Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance to...Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain,but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical.In this study,ischemic stroke was induced in rats through middle cerebral artery occlusion surgery.Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia,and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation.Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation.Furthermore,the stimulation promoted motor function recovery,reduced cerebral infarction volume in the rat model of ischemic stroke,and induced the expression of brain-derived neurotrophic factor in the ischemic brain.Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume.This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia.Additionally,our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo.These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke.展开更多
Background:Platinum can cause chemotherapy-related cognitive impairment.Low-intensity focused ultrasound(LIFUS)is a promising noninvasive physical stimulation method with a unique advantage in neurological rehabilitat...Background:Platinum can cause chemotherapy-related cognitive impairment.Low-intensity focused ultrasound(LIFUS)is a promising noninvasive physical stimulation method with a unique advantage in neurological rehabilitation.We aimed to investigate whether LIFUS can alleviate cisplatin-induced cognitive impairment in rats and explore the related neuropatho-logical mechanisms.Methods:After confirming the target position for LIFUS treatment in 18 rats,64 rats were randomly divided into four groups:control,model,sham,and LIFUS groups.Before and after LIFUS treatment,detailed biological behavioral assessments and magnetic resonance imaging were performed.Finally,the rats were euthanized,and relevant histopathological and molecular biological experiments were conducted and analyzed.Results:In the Morris water maze,the model group showed fewer platform crossings(1.250.93 vs.5.691.58),a longer escape latency(41.6536.55 s vs.6.382.11 s),and a lower novel object recognition index(29.7711.83 vs.83.695.67)than the control group.LIFUS treatment improved these metrics,with more platform crossings(3.130.34),a higher recognition index(65.588.71),and a shorter escape latency(6.452.27 s).Longitudinal analysis of the LIFUS group further confirmed these improvements.Neuroimaging revealed significant differences in diffusion tensor imaging metrics of specific brain regions pre-and post-LIFUS.Moreover,neuropathology showed higher dendritic spine density,less myelin loss,fewer apoptotic cells,more synapses,and less mitochondrial autophagy after LIFUS treatment.The neuroimaging indicators were correlated with behavioral improvements,highlighting the potential of LIFUS for alleviating cognitive impairment(as demonstrated through imaging and analysis).Our investigation of the molecular biological mechanisms revealed distinct protein expression patterns in the hippocampus and its subregions.In the model group,glial fibrillary acidic protein(GFAP)and ionized calcium-binding adaptor molecule 1(IBA1)expression levels were elevated across the hippocampus,whereas neuronal nuclei(NeuN)expression was reduced.Subregional analysis revealed higher GFAP and IBA1 and lower NeuN,especially in the dentate gyrus subregion.Moreover,positive cell areas were larger in the cornu ammonis(CA)1,CA2,CA3,and dentate gyrus regions.In the CA2 and CA3,significant differences among the groups were observed in GFAP-positive cell counts and areas,and there were variations in NeuN expression.Conclusions:Our results suggest that LIFUS can reverse cisplatin-induced cognitive impairments.The neuroimaging findings were consistent with the behavioral and histological results and suggest a neuropathological basis that supports further research into the clinical applications of LIFUS.Furthermore,LIFUS appeared to enhance the plasticity of neuronal synapses in the rat hippocampus and reduce hippocampal inflammation.These findings highlight the clinical potential of LIFUS as an effective,noninvasive therapeutic strategy and monitoring tool for chemotherapy-induced cognitive deficits.展开更多
Techniques for manipulating nanodroplets lie at the core of numerous miniaturized systems in chemical and biological research endeavors.In this study,we introduce a versatile methodology for calculating the acoustic v...Techniques for manipulating nanodroplets lie at the core of numerous miniaturized systems in chemical and biological research endeavors.In this study,we introduce a versatile methodology for calculating the acoustic vortex field,integrating hybrid wave equation principles with ray acoustics.This approach demonstrates remarkable consistency between simulated results and experimental observations.Importantly,both theoretical analysis and experimental validation confirm that particles whose diameters match the wavelength(Mie particles)can be effectively trapped within a focused acoustic vortex field,rotating in circular trajectories centered at the vortex center.This research significantly expands the scope of acoustic vortex manipulation for larger particles and introduces a novel implementation strategy with potential applications in targeted drug delivery for clinical adjuvant therapy.展开更多
Transcranial focused ultrasound(tFUS)is an emerging modality with strong potential for non-invasively treating brain disorders.However,the inhomogeneity and complex structure of the skull induce substantial phase aber...Transcranial focused ultrasound(tFUS)is an emerging modality with strong potential for non-invasively treating brain disorders.However,the inhomogeneity and complex structure of the skull induce substantial phase aberrations and pressure attenuation;these can distort and shift the acoustic focus,thus hindering the efficiency of tFUS therapy.To achieve effective treatments,phased array transducers combined with aberration correction algorithms are commonly implemented.The present report aims to provide a comprehensive review of the current methods used for tFUS phase aberration correction.We first searched the PubMed and Web of Science databases for studies on phase aberration correction algorithms,identifying 54 articles for review.Relevant information,including the principles of algorithms and refocusing performances,were then extracted from the selected articles.The phase correction algorithms involved two main steps:acoustic field estimation and transmitted pulse adjustment.Our review identified key benchmarks for evaluating the effectiveness of these algorithms,each of which was used in at least three studies.These benchmarks included pressure and intensity,positioning error,focal region size,peak sidelobe ratio,and computational efficiency.Algorithm performances varied under different benchmarks,thus highlighting the importance of application-specific algorithm selection for achieving optimal tFUS therapy outcomes.The present review provides a thorough overview and comparison of various phase correction algorithms,and may offer valuable guidance to tFUS researchers when selecting appropriate phase correction algorithms for specific applications.展开更多
Focused ultrasound(FUS)therapy generates sufficient heat for medical interventions like tumor ablation by concentrating energy at the focal point.The complex viscoelastic properties of biological tissues pose challeng...Focused ultrasound(FUS)therapy generates sufficient heat for medical interventions like tumor ablation by concentrating energy at the focal point.The complex viscoelastic properties of biological tissues pose challenges in balancing focusing precision and penetration depth,impacting the safety of surrounding tissues and treatment efficacy.This study develops an acoustic-solid-thermal coupling computational model to elucidate the dynamic mechanical response and energy dissipation mechanisms of soft tissue during FUS thermal therapy using a hyper-viscoelastic constitutive model.Results indicate that the high compressibility and low shear resistance of biological tissues result in a unique shear dissipation mechanism.Energy dissipation efficiency per area is indirectly influenced by load frequency via its effect on the dynamic shear modulus and is directly proportional to load amplitude.Focusing precision,represented by the focal zone width,is inversely controlled by frequency via wavelength.A mathematical model for evaluating temperature rise efficiency is proposed,and an optimal frequency for efficient FUS thermal therapy in brain-like soft materials is identified.This research elucidates the link between viscoelastic tissue behavior and FUS treatment outcomes,offering insights for optimizing FUS applications in various medical fields.展开更多
This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-s...This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-source software Open FOAM~?, a two-dimensional viscous-flow numerical wave flume was developed to simulate the fluid resonant motions induced by transient focused wave groups with different spectral peak periods and wave amplitudes. The results indicate that for all the incident focused wave amplitudes considered, the amplitudes of the free surface elevation in the gap, horizontal wave force and moment all exhibit a bimodal variation trend with increasing spectral peak period. The peak values of the above amplitude-period curve appear near the resonant period of the first and second harmonic components of the free surface elevation. However, the variation in the vertical wave force versus the spectral peak period presents different patterns. In addition, the first-to fourth-order harmonic components in the wave surface and forces are further examined via the four-phase combination method. The results show that the first-to secondorder harmonic components play a dominant role in the overall amplitude.展开更多
[Objectives]To investigate the effect of low-intensity focused ultrasound(LIFU)on rats with spinal cord injury(SCI)by examining the expression of calcineurin(CaN)and nuclear factor of activated T-cells(NFAT)in the inj...[Objectives]To investigate the effect of low-intensity focused ultrasound(LIFU)on rats with spinal cord injury(SCI)by examining the expression of calcineurin(CaN)and nuclear factor of activated T-cells(NFAT)in the injured spinal cord region following LIFU intervention.[Methods]Twenty-four specific pathogen-free(SPF)female Wistar rats,aged 7-8 weeks(160-180 g),were selected.Six rats were randomly assigned to the sham-operated group(SHAM),undergoing laminectomy only without spinal cord injury.Spinal cord injury models were established in the remaining rats using a modified Allen s weight-drop method at the T10 thoracic vertebral level.The 18 rats with successful modeling were then randomly divided into the spinal cord injury model group(SCI group),LIFU treatment group 1(T1 group),and LIFU treatment group 2(T2 group),with six rats in each group.LIFU treatment(for T1 and T2 groups)commenced on day 4 after injury,administered once daily for 20 min per session,for a total of 11 consecutive days.Tissues were harvested on day 14.Changes in CaN and NFAT4 mRNA expression were assessed using quantitative polymerase chain reaction(qPCR).Changes in CaN and NFAT4 protein expression were evaluated by Western blot analysis.[Results]qPCR analysis revealed that compared to the SHAM group,mRNA expression levels of both CaN and NFAT4 were decreased in the SCI group;compared to the SCI group,mRNA expression levels of CaN and NFAT4 were increased in both the T1 and T2 groups;furthermore,compared to the T1 group,mRNA expression levels of CaN and NFAT4 were higher in the T2 group.Western Blot analysis showed that compared to the SHAM group,protein expression levels of both CaN and NFAT4 were downregulated in the SCI group;compared to the SCI group,protein expression levels of CaN and NFAT4 were increased in both the T1 and T2 groups;moreover,compared to the T1 group,protein expression levels of CaN and NFAT4 were higher in the T2 group.[Conclusions]LIFU may contribute to functional recovery in SCI rats by modulating the expression levels of CaN and NFAT4.展开更多
The noninvasive ablation of pancreatic cancer with high intensity focused ultrasound(HIFU) energy is received increasingly widespread interest. With rapidly temperature rise to cytotoxic levels within the focal volume...The noninvasive ablation of pancreatic cancer with high intensity focused ultrasound(HIFU) energy is received increasingly widespread interest. With rapidly temperature rise to cytotoxic levels within the focal volume of ultrasound beams, HIFU can selectively ablate a targeted lesion of the pancreas without any damage to surrounding or overlying tissues. Preliminary studies suggest that this approach is technical safe and feasible, and can be used alone or in combination with systemic chemotherapy for the treatment of patients with locally advanced pancreatic cancer. It can effectively alleviate cancer-related abdominal pain, and may confer an additional survival benefit with few significant complications. This review provides a brief overview of HIFU, describes current clinical applications, summarizes characteristics of continuous and pulsed HIFU, and discusses future applications and challenges in the treatment of pancreatic cancer.展开更多
It has long been noticed that focus is able to influence the truth-conditions of coun-terfactual conditionals.Namely,stressing different parts of a counterfactual leads to distinct interpretations.However,existing the...It has long been noticed that focus is able to influence the truth-conditions of coun-terfactual conditionals.Namely,stressing different parts of a counterfactual leads to distinct interpretations.However,existing theories,such as those by von Finte1 and Rooth,fail to ad-equately account for this phenomenon.In this paper,I exposit the drawbacks of these theories and then propose a novel account,ie.the Good Question-Answer(GQA)view.The GQA account posits that focus triggers question-answer pairs,and pragmatic pressures conceming the adequacy of such question answer pairs in contexts are able to affect the truth-conditions of counterfactuals.I also argue for the GQA account by appeal to its theoretical virtues.展开更多
Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is an emerging, non-invasive hyperthermia technology which can be used for the treatment of benign and malignant tumours, in conjunction with intracranial ...Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is an emerging, non-invasive hyperthermia technology which can be used for the treatment of benign and malignant tumours, in conjunction with intracranial neurological diseases. To treat different indications, it is often necessary to design special focused ultrasound devices and treatment plans, which poses great challenges and results in substantial costs during software development. This article introduces a general software architecture that can be applied to three different focused ultrasound devices for the treatment of uterine fibroids, breast fibroids, and pain palliation of bone metastases, respectively, and can be integrated with GE Discovery or Signa MRI scanners and Xingaoyi BroadScan MRI scanners. Finally, the proposed software architecture was shown to possess desirable universality and safety through various tests and animal experimental studies.展开更多
Background: The unaesthetic appearance of the female intimate area (vulva, “mound of venus” and perianal region) is a triggering factor of negative psychological responses, embarrassment, anxiety and insecurity in m...Background: The unaesthetic appearance of the female intimate area (vulva, “mound of venus” and perianal region) is a triggering factor of negative psychological responses, embarrassment, anxiety and insecurity in many women. Using rejuvenating equipment for vaginal structure or for the intimate area as a whole is already widespread in the literature, and High-Intensity Focused Ultrasound (HIFU) has proven to be very effective in the clinical practice of many professionals. This study, therefore, aims to describe the fundamentals and applicability that guide the use of HIFU in vulvar rejuvenation. Materials and Methods: Exploratory research was carried out, presented in a narrative review, to highlight the action of HIFU in female intimate rejuvenation. The review explored scientific articles published and available in the following databases: MEDLINE (Medical Literature Analysis and Retrieval System Online), PubMed (National Library of Medicine), SCIELO (Scientific Electronic Library Online), and LILACS (Latin Literature American and the Caribbean in Health Sciences). In addition, some clinical findings obtained through a retrospective analysis of medical records were added to describe the authors’ clinical experience in the use of Focused Ultrasound (HIFU) for vulvar rejuvenation. Results: We verified that the tissues of female external genitalia respond very well to the stimuli of the focused sound waves of the HIFU, being able to produce immediate and lasting results through isolated applications or in association with intradermotherapy or other therapeutic resources. Conclusion: We conclude that using High Intensity Focused Ultrasound aimed at vulvar rejuvenation is safely indicated and assures excellent aesthetic results at the end of the treatment because similarly to other treatment techniques, the thermal stimuli of HIFU are also able to produce an excellent therapeutic response in the dermal tissue of the female intimate area, promoting intense neocollagenesis and generating great aesthetic improvement.展开更多
AIM:To analyze whether high-intensity focused ultrasound(HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma(HCC).METHODS:From January 2007 to December 2010,49 consecutive HCC pa...AIM:To analyze whether high-intensity focused ultrasound(HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma(HCC).METHODS:From January 2007 to December 2010,49 consecutive HCC patients were listed for liver transplantation(UCSF criteria).The median waiting time for transplantation was 9.5 mo.Twenty-nine patients received transarterial chemoembolization(TACE) as a bringing therapy and 16 patients received no treatment before transplantation.Five patients received HIFU ablation as a bridging therapy.Another five patients with the same tumor staging(within the UCSF criteria) who received HIFU ablation but not on the transplant list were included for comparison.Patients were comparable in terms of Child-Pugh and model for end-stage liver disease scores,tumor size and number,and cause of cirrhosis.RESULTS:The HIFU group and TACE group showed no difference in terms of tumor size and tumor number.One patient in the HIFU group and no patient in the TACE group had gross ascites.The median hospital stay was 1 d(range,1-21 d) in the TACE group and two days(range,1-9 d) in the HIFU group(P < 0.000).No HIFU-related complication occurred.In the HIFU group,nine patients(90%) had complete response and one patient(10%) had partial response to the treatment.In the TACE group,only one patient(3%) had response to the treatment while 14 patients(48%) had stable disease and 14 patients(48%) had progressive disease(P = 0.00).Seven patients in the TACE group and no patient in the HIFU group dropped out from the transplant waiting list(P = 0.559).CONCLUSION:HIFU ablation is safe and effective in the treatment of HCC for patients with advanced cirrhosis.It may reduce the drop-out rate of liver transplant candidate.展开更多
Recent advances in high intensity focused ultrasound(HIFU),which was developed in the 1940s as a viable thermal tissue ablation approach,have increased its popularity.In clinics,HIFU has been applied to treat a variet...Recent advances in high intensity focused ultrasound(HIFU),which was developed in the 1940s as a viable thermal tissue ablation approach,have increased its popularity.In clinics,HIFU has been applied to treat a variety of solid malignant tumors in a well-defined volume,including the pancreas,liver,prostate,breast,uterine fibroids,and soft-tissue sarcomas.In comparison to conventional tumor/cancer treatment modalities,such as open surgery,radio-and chemo-therapy,HIFU has the advantages of non-invasion,non-ionization,and fewer complications after treatment.Over 100 000 cases have been treated throughout the world with great success.The fundamental principles of HIFU ablation are coagulative thermal necrosis due to the absorption of ultrasound energy during transmission in tissue and the induced cavitation damage.This paper reviews the clinical outcomes of HIFU ablation for applicable cancers,and then summarizes the recommendations for a satisfactory HIFU treatment according to clinical experience.In addition,the current challenges in HIFU for engineers and physicians are also included.More recent horizons have broadened the application of HIFU in tumor treatment,such as HIFU-mediated drug delivery,vessel occlusion,and soft tissue erosion(“histotripsy”).In summary,HIFU is likely to play a significant role in the future oncology practice.展开更多
AIM： To analyze the local and systemic complications of high intensity focused ultrasound （HIFU） for patients with recurrent and metastatic abdominal tumors. METHODS： From Aug 2001 to Aug 2004, 17 patients with re...AIM： To analyze the local and systemic complications of high intensity focused ultrasound （HIFU） for patients with recurrent and metastatic abdominal tumors. METHODS： From Aug 2001 to Aug 2004, 17 patients with recurrent and metastatic abdominal tumors were enrolled in this study. Real-time sonography was taken, and vital signs, liver and kidney function, skin burns, local reactions, and systemic effects were observed and recored before, during, and after HIFU. CT and MR/were also taken before and after HIFU. RESULTS： All 17 patients had skin burns and pain in the treatment region; the next common complication was neurapraxia of the stomach and intestines to variable degrees. The other local and systemic complications were relatively rare. Severe complications were present in two patients; one developed a superior mesenteric artery infarction resulting in necrosis of the entire small intestines, and the other one suffered from a perforation in terminal ileum due to HIFU treatment. CONCLUSION： Although HIFU is a one of noninvasive treatments for the recurrent and metastatic abdominal tumors, there are still some common and severe complications which need serious consideration.展开更多
AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocell...AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocellular carcinoma were used to generate antitumor vaccines.Ten mice underwent HIFU ablation,and the remaining 10 mice received a sham-HIFU procedure with no ultrasound irradiation.Sixty normal mice were randomly divided into HIFU vaccine,tumor vaccine and control groups.These mice were immunized with HIFU-generated vaccine,tumor-generated vaccine,and saline,respectively.In addition,20 mice bearing H22 tumors were successfully treated with HIFU ablation. The protective immunity of the vaccinated mice was investigated before and after a subsequent H22 tumor challenge.Using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay,the cytotoxicity of splenic lymphocytes co-cultured with H22 cells wasdetermined in vitro before the tumor challenge,and tumor volume and survival were measured in vivo after the challenge in each group.The mechanism was also explored by loading the vaccines with bone marrowderived dendritic cells(DCs). RESULTS:Compared to the control,HIFU therapy, tumor-generated and HIFU-generated vaccines significantly increased cytolytic activity against H22 cells in the splenocytes of the vaccinated mice(P<0.001). The tumor volume was significantly smaller in the HIFU vaccine group than in the tumor vaccine group(P <0.05)and control group(P<0.01).However,there was no tumor growth after H22 rechallenge in the HIFU therapy group.Forty-eight-day survival rate was 100%in mice in the HIFU therapy group,30%in both the HIFU vaccine and tumor vaccine groups,and 20% in the control group,indicating that the HIFU-treated mice displayed significantly longer survival than the vaccinated mice in the remaining three groups(P< 0.001).After bone marrow-derived DCs were incubated with HIFU-generated and tumor-generated vaccines, the number of mature DCs expressing MHC-Ⅱ + ,CD80 + and CD86 + molecules was significantly increased,and interleukin-12 and interferon-γlevels were significantly higher in the supernatants when compared with immature DCs incubated with mouse serum(P<0.001). However,no differences of the number of mature DCs and cytokine levels were observed between the HIFU- generated and tumor-generated vaccines(P>0.05). CONCLUSION:Tumor debris remaining after HIFU can improve tumor immunogenicity.This debris releases tumor antigens as an effective vaccine to develop host antitumor immune response after HIFU ablation.展开更多
The origin and migration of natural gas and the accumulation of gas hydrates within the Pearl River Mouth Basin of the northern South China Sea are poorly understood. Based on high-resolution 2D/3D seismic data, three...The origin and migration of natural gas and the accumulation of gas hydrates within the Pearl River Mouth Basin of the northern South China Sea are poorly understood. Based on high-resolution 2D/3D seismic data, three environments of focused fluid flow： gas chimneys, mud diapirs and active faults have been identified. Widespread gas chimneys that act as important conduits for fluid flow are located below bottom simulating reflections and above basal uplifts. The occurrence and evolution of gas chimneys can be divided into a violent eruptive stage and a quiet seepage stage. For most gas chimneys, the strong eruptions are deduced to have happened during the Dongsha Movement in the latest Miocene, which are observed below Pliocene strata and few active faults develop above the top of the Miocene. The formation pressures of the Baiyun Sag currently are considered to be normal, based on these terms： 1） Borehole pressure tests with pressure coefficients of 1.043-l.047; 2） The distribution of gas chimneys is limited to strata older than the Pliocene; 3） Disseminated methane hydrates, rather than fractured hydrates, are found in the hydrate samples; 4） The gas hydrate is mainly charged with biogenic gas rather than thermogenic gas based on the chemical tests from gas hydrates cores. However, periods of quiet focused fluid flow also enable the establishment of good conduits for the migration of abundant biogenic gas and lesser volumes ofthermogenic gas. A geological model goveming fluid flow has been proposed to interpret the release of overpressure, the migration of fluids and the formation of gas hydrates, in an integrated manner. This model suggests that gas chimneys positioned above basal uplifts were caused by the Dongsha Movement at about 5.5 Ma. Biogenic gas occupies the strata above the base of the middle Miocene and migrates slowly into the gas chimney columns. Some of the biogenic gas and small volumes ofthermogenic gas eventually contribute to the formation of the gas hydrates.展开更多
High-intensity focused ultrasound(HIFU)is a noninvasive modality that uses an extracorporeal source of focused ultrasound energy.This technique was introduced by Lynn et al and is able to induce coagulative necrosis i...High-intensity focused ultrasound(HIFU)is a noninvasive modality that uses an extracorporeal source of focused ultrasound energy.This technique was introduced by Lynn et al and is able to induce coagulative necrosis in selected tissues without damaging adjacent structures.Although HIFU has been studied for 50years,recent technological developments now allow its use for tumours of the liver,prostate and other sites.In liver disease,HIFU has been used to treat unresectable,advanced stages of hepatocellular carcinoma(HCC)and liver metastases.Hepatocellular carcinoma is a serious health problem worldwide and is endemic in some areas because of its association with hepatitis B and C viruses(in 20%of cases).Liver transplantation(LT)has become one of the best treatments available because it removes both the tumour and the underlying liver disease such as cirrhosis(which is present in approximately 80%of cases).The prerequisite for longterm transplant success depends on tumour load and strict selection criteria regarding the size and number of tumour nodules.The need to obtain the optimal benefit from the limited number of organs available has prompted strict selection criteria limited to only those patients with early HCC who have a better long-term outcome after LT.The so-called"bridging therapy"has the aim of controlling disease burden for patients who are on the organ transplant waiting list.Amongst various treatment options,transarterial chemoembolisation and radiofrequency ablation are the most popular treatment choices.Recently,Cheung et al demonstrated that HIFU ablation is a safe and effective method for the treatment of HCC patients with advanced cirrhosis as a bridging therapy and that it reduced the dropout rate from the liver transplant waiting list.In this commentary,we discuss the current value of HIFU in the treatment of liver disease,including its value as a bridging therapy,and examine the potential advantages of other therapeutic strategies.展开更多
AIM:To evaluate the safety and clinical application of high-intensity focused ultrasound(HIFU)therapy for unresectable pancreatic cancer(PC).METHODS:Thirty PC patients(16 cases in stage III and 14 cases in stage IV)wi...AIM:To evaluate the safety and clinical application of high-intensity focused ultrasound(HIFU)therapy for unresectable pancreatic cancer(PC).METHODS:Thirty PC patients(16 cases in stage III and 14 cases in stage IV)with visualized pancreatic tumors were admitted for HIFU therapy as an optional local therapy in addition to systemic chemotherapy or chemoradiotherapy.Informed consent was obtained.This study began at the end of 2008 and was approved by the ethics committee of our hospital[Institutional Review Board(IRB):890].The HIFU device used was the FEP-BY02(Yuande Bio-Medical Engineering,Beijing,China).RESULTS:The mean tumor size after HIFU therapy changed to 30.9±1.7 mm from 31.7±1.7 mm at pre-therapy.There were no significant changes in tumor size,mean number of treatment sessions(2.7±0.1 mm),or mean total treatment time(2.4±0.1 h).The rate of symptom relief effect was 66.7%.The effectiveness of primary lesion treatment was as follows:complete response,0;partial response,4;stable disease,22;progressive disease,4.Treatment after HIFU therapy included 2 operations,24 chemotherapy treatments,and 4 best supportive care treatments.Adverse events occurred in 10%of cases,namely pseudocyst formation in 2 cases and mild pancreatitis development in 1.However,no severe adverse events occurred in this study.CONCLUSION:We suggest that HIFU therapy is safe and has the potential to be a new method of combination therapy for PC.展开更多
BACKGROUND: High-intensity focused ultrasound (HIFU) is a non-invasive method of solid tissue ablation therapy. However, only a few studies have reported the effect of HIFU for unresectable pancreatic cancer. This stu...BACKGROUND: High-intensity focused ultrasound (HIFU) is a non-invasive method of solid tissue ablation therapy. However, only a few studies have reported the effect of HIFU for unresectable pancreatic cancer. This study aimed to evaluate the clinical benefits, survival time and complications associated with the use of HIFU ablation in patients with unresectable pancreatic cancer. METHODS: Twenty-five patients with unresectable pancreatic cancer were enrolled in our study. All patients received HIFU therapy for tumors at least once. The therapeutic effects of HIFU was evaluated in terms of Karnofsky performance status (KPS) scores, pain relief, serum CA19-9, and imaging by B-US and CT before and after the therapy. We also recorded median overall survival time and complications caused by the treatment. RESULTS: In the 25 patients, KPS scores were above 60, and increased KPS was observed in 23 patients after treatment. Pain relief occurred in 23 patients. Serum CA19-9 levels were significantly reduced one month after HIFU treatment and became negative in 5 patients. B-US revealed enhanced tumor echogenicity in 13 patients and decreased tumor blood supply in 9. Tumor necrosis was confirmed by CT in 8 patients one month after HIFU treatment. The median overall survival time was 10 months, and the 1-year survival rate was 42%. No severe complications were observed after HIFU treatment. CONCLUSION: HIFU can effectively relieve pain, increase KPS, decrease tumor growth and prolong the survival time of patients with unresectable pancreatic cancer.展开更多
In this paper, a numerical model is developed based on the High Order Spectral （HOS） method with a non-periodic boundary. A wave maker boundary condition is introduced to simulate wave generation at the incident bou...In this paper, a numerical model is developed based on the High Order Spectral （HOS） method with a non-periodic boundary. A wave maker boundary condition is introduced to simulate wave generation at the incident boundary in the HOS method. Based on the numerical model, the effects of wave parameters, such as the assumed focused amplitude, the central frequency, the frequency bandwidth, the wave amplitude distribution and the directional spreading on the surface elevation of the focused wave, the maximum generated wave crest, and the shifting of the focusing point, are numerically investigated. Especially, the effects of the wave directionality on the focused wave properties are emphasized. The numerical results show that the shifting of the focusing point and the maximum crest of the wave group are dependent on the amplitude of the focused wave, the central frequency, and the wave amplitude distribution type. The wave directionality has a definite effect on multidirectional focused waves. Generally, it can even out the difference between the simulated wave amplitude and the amplitude expected from theory and reduce the shifting of the focusing points, implying that the higher order interaction has an influence on wave focusing, especially for 2D wave. In 3D wave groups, a broader directional spreading weakens the higher nonlinear interactions.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,Nos.G2021KY05107,G2021KY05101the National Natural Science Foundation of China,Nos.32071316,32211530049+1 种基金the Natural Science Foundation of Shaanxi Province,No.2022-JM482the Education and Teaching Reform Funds for the Central Universities,No.23GZ230102(all to LL and HH).
文摘Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain,but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical.In this study,ischemic stroke was induced in rats through middle cerebral artery occlusion surgery.Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia,and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation.Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation.Furthermore,the stimulation promoted motor function recovery,reduced cerebral infarction volume in the rat model of ischemic stroke,and induced the expression of brain-derived neurotrophic factor in the ischemic brain.Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume.This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia.Additionally,our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo.These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke.
基金supported by the National Natural Science Foundation of China(82171908 and 82102015)the General Project of the Nanjing Medical Science and Technology Development Program(YKK21075)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515140030).
文摘Background:Platinum can cause chemotherapy-related cognitive impairment.Low-intensity focused ultrasound(LIFUS)is a promising noninvasive physical stimulation method with a unique advantage in neurological rehabilitation.We aimed to investigate whether LIFUS can alleviate cisplatin-induced cognitive impairment in rats and explore the related neuropatho-logical mechanisms.Methods:After confirming the target position for LIFUS treatment in 18 rats,64 rats were randomly divided into four groups:control,model,sham,and LIFUS groups.Before and after LIFUS treatment,detailed biological behavioral assessments and magnetic resonance imaging were performed.Finally,the rats were euthanized,and relevant histopathological and molecular biological experiments were conducted and analyzed.Results:In the Morris water maze,the model group showed fewer platform crossings(1.250.93 vs.5.691.58),a longer escape latency(41.6536.55 s vs.6.382.11 s),and a lower novel object recognition index(29.7711.83 vs.83.695.67)than the control group.LIFUS treatment improved these metrics,with more platform crossings(3.130.34),a higher recognition index(65.588.71),and a shorter escape latency(6.452.27 s).Longitudinal analysis of the LIFUS group further confirmed these improvements.Neuroimaging revealed significant differences in diffusion tensor imaging metrics of specific brain regions pre-and post-LIFUS.Moreover,neuropathology showed higher dendritic spine density,less myelin loss,fewer apoptotic cells,more synapses,and less mitochondrial autophagy after LIFUS treatment.The neuroimaging indicators were correlated with behavioral improvements,highlighting the potential of LIFUS for alleviating cognitive impairment(as demonstrated through imaging and analysis).Our investigation of the molecular biological mechanisms revealed distinct protein expression patterns in the hippocampus and its subregions.In the model group,glial fibrillary acidic protein(GFAP)and ionized calcium-binding adaptor molecule 1(IBA1)expression levels were elevated across the hippocampus,whereas neuronal nuclei(NeuN)expression was reduced.Subregional analysis revealed higher GFAP and IBA1 and lower NeuN,especially in the dentate gyrus subregion.Moreover,positive cell areas were larger in the cornu ammonis(CA)1,CA2,CA3,and dentate gyrus regions.In the CA2 and CA3,significant differences among the groups were observed in GFAP-positive cell counts and areas,and there were variations in NeuN expression.Conclusions:Our results suggest that LIFUS can reverse cisplatin-induced cognitive impairments.The neuroimaging findings were consistent with the behavioral and histological results and suggest a neuropathological basis that supports further research into the clinical applications of LIFUS.Furthermore,LIFUS appeared to enhance the plasticity of neuronal synapses in the rat hippocampus and reduce hippocampal inflammation.These findings highlight the clinical potential of LIFUS as an effective,noninvasive therapeutic strategy and monitoring tool for chemotherapy-induced cognitive deficits.
基金Project supported by the National Key R&D Program of China(Grant No.2023YFE0201900)。
文摘Techniques for manipulating nanodroplets lie at the core of numerous miniaturized systems in chemical and biological research endeavors.In this study,we introduce a versatile methodology for calculating the acoustic vortex field,integrating hybrid wave equation principles with ray acoustics.This approach demonstrates remarkable consistency between simulated results and experimental observations.Importantly,both theoretical analysis and experimental validation confirm that particles whose diameters match the wavelength(Mie particles)can be effectively trapped within a focused acoustic vortex field,rotating in circular trajectories centered at the vortex center.This research significantly expands the scope of acoustic vortex manipulation for larger particles and introduces a novel implementation strategy with potential applications in targeted drug delivery for clinical adjuvant therapy.
基金supported by Start-Up Grant From ShanghaiTech University,2021F0209-000-09Natural Science Foundation of Shanghai Municipality,23ZR1442000。
文摘Transcranial focused ultrasound(tFUS)is an emerging modality with strong potential for non-invasively treating brain disorders.However,the inhomogeneity and complex structure of the skull induce substantial phase aberrations and pressure attenuation;these can distort and shift the acoustic focus,thus hindering the efficiency of tFUS therapy.To achieve effective treatments,phased array transducers combined with aberration correction algorithms are commonly implemented.The present report aims to provide a comprehensive review of the current methods used for tFUS phase aberration correction.We first searched the PubMed and Web of Science databases for studies on phase aberration correction algorithms,identifying 54 articles for review.Relevant information,including the principles of algorithms and refocusing performances,were then extracted from the selected articles.The phase correction algorithms involved two main steps:acoustic field estimation and transmitted pulse adjustment.Our review identified key benchmarks for evaluating the effectiveness of these algorithms,each of which was used in at least three studies.These benchmarks included pressure and intensity,positioning error,focal region size,peak sidelobe ratio,and computational efficiency.Algorithm performances varied under different benchmarks,thus highlighting the importance of application-specific algorithm selection for achieving optimal tFUS therapy outcomes.The present review provides a thorough overview and comparison of various phase correction algorithms,and may offer valuable guidance to tFUS researchers when selecting appropriate phase correction algorithms for specific applications.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11972205,11921002,11972210,and 12302096)the National Key Research Development Program of China(Grant No.2020-JCJQ-ZD-254).
文摘Focused ultrasound(FUS)therapy generates sufficient heat for medical interventions like tumor ablation by concentrating energy at the focal point.The complex viscoelastic properties of biological tissues pose challenges in balancing focusing precision and penetration depth,impacting the safety of surrounding tissues and treatment efficacy.This study develops an acoustic-solid-thermal coupling computational model to elucidate the dynamic mechanical response and energy dissipation mechanisms of soft tissue during FUS thermal therapy using a hyper-viscoelastic constitutive model.Results indicate that the high compressibility and low shear resistance of biological tissues result in a unique shear dissipation mechanism.Energy dissipation efficiency per area is indirectly influenced by load frequency via its effect on the dynamic shear modulus and is directly proportional to load amplitude.Focusing precision,represented by the focal zone width,is inversely controlled by frequency via wavelength.A mathematical model for evaluating temperature rise efficiency is proposed,and an optimal frequency for efficient FUS thermal therapy in brain-like soft materials is identified.This research elucidates the link between viscoelastic tissue behavior and FUS treatment outcomes,offering insights for optimizing FUS applications in various medical fields.
基金financially supported by the National Natural Science Foundation of China (Grant No. 52371277)the State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation (Tianjin University)(Grant No. HESS-2323)+2 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province (Grant No. KYCX24_4071)the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2023A1515010890)the Open foundation of Key Laboratory of Port.Waterway&Sedimentation Engineering (Grant No. Yk224001-1)。
文摘This paper explores the phenomenon of fluid resonance occurring within a narrow gap between a vessel and a vertical wharf, taking ships berthing in front of a gravity wharf as the research background. Using the open-source software Open FOAM~?, a two-dimensional viscous-flow numerical wave flume was developed to simulate the fluid resonant motions induced by transient focused wave groups with different spectral peak periods and wave amplitudes. The results indicate that for all the incident focused wave amplitudes considered, the amplitudes of the free surface elevation in the gap, horizontal wave force and moment all exhibit a bimodal variation trend with increasing spectral peak period. The peak values of the above amplitude-period curve appear near the resonant period of the first and second harmonic components of the free surface elevation. However, the variation in the vertical wave force versus the spectral peak period presents different patterns. In addition, the first-to fourth-order harmonic components in the wave surface and forces are further examined via the four-phase combination method. The results show that the first-to secondorder harmonic components play a dominant role in the overall amplitude.
文摘[Objectives]To investigate the effect of low-intensity focused ultrasound(LIFU)on rats with spinal cord injury(SCI)by examining the expression of calcineurin(CaN)and nuclear factor of activated T-cells(NFAT)in the injured spinal cord region following LIFU intervention.[Methods]Twenty-four specific pathogen-free(SPF)female Wistar rats,aged 7-8 weeks(160-180 g),were selected.Six rats were randomly assigned to the sham-operated group(SHAM),undergoing laminectomy only without spinal cord injury.Spinal cord injury models were established in the remaining rats using a modified Allen s weight-drop method at the T10 thoracic vertebral level.The 18 rats with successful modeling were then randomly divided into the spinal cord injury model group(SCI group),LIFU treatment group 1(T1 group),and LIFU treatment group 2(T2 group),with six rats in each group.LIFU treatment(for T1 and T2 groups)commenced on day 4 after injury,administered once daily for 20 min per session,for a total of 11 consecutive days.Tissues were harvested on day 14.Changes in CaN and NFAT4 mRNA expression were assessed using quantitative polymerase chain reaction(qPCR).Changes in CaN and NFAT4 protein expression were evaluated by Western blot analysis.[Results]qPCR analysis revealed that compared to the SHAM group,mRNA expression levels of both CaN and NFAT4 were decreased in the SCI group;compared to the SCI group,mRNA expression levels of CaN and NFAT4 were increased in both the T1 and T2 groups;furthermore,compared to the T1 group,mRNA expression levels of CaN and NFAT4 were higher in the T2 group.Western Blot analysis showed that compared to the SHAM group,protein expression levels of both CaN and NFAT4 were downregulated in the SCI group;compared to the SCI group,protein expression levels of CaN and NFAT4 were increased in both the T1 and T2 groups;moreover,compared to the T1 group,protein expression levels of CaN and NFAT4 were higher in the T2 group.[Conclusions]LIFU may contribute to functional recovery in SCI rats by modulating the expression levels of CaN and NFAT4.
文摘The noninvasive ablation of pancreatic cancer with high intensity focused ultrasound(HIFU) energy is received increasingly widespread interest. With rapidly temperature rise to cytotoxic levels within the focal volume of ultrasound beams, HIFU can selectively ablate a targeted lesion of the pancreas without any damage to surrounding or overlying tissues. Preliminary studies suggest that this approach is technical safe and feasible, and can be used alone or in combination with systemic chemotherapy for the treatment of patients with locally advanced pancreatic cancer. It can effectively alleviate cancer-related abdominal pain, and may confer an additional survival benefit with few significant complications. This review provides a brief overview of HIFU, describes current clinical applications, summarizes characteristics of continuous and pulsed HIFU, and discusses future applications and challenges in the treatment of pancreatic cancer.
基金supported by the Major Program of National Social Science Foundation of China(No.23&ZD240)。
文摘It has long been noticed that focus is able to influence the truth-conditions of coun-terfactual conditionals.Namely,stressing different parts of a counterfactual leads to distinct interpretations.However,existing theories,such as those by von Finte1 and Rooth,fail to ad-equately account for this phenomenon.In this paper,I exposit the drawbacks of these theories and then propose a novel account,ie.the Good Question-Answer(GQA)view.The GQA account posits that focus triggers question-answer pairs,and pragmatic pressures conceming the adequacy of such question answer pairs in contexts are able to affect the truth-conditions of counterfactuals.I also argue for the GQA account by appeal to its theoretical virtues.
基金the National Natural Science Foundation of China (Nos. 81727806 and 11774231)the National Key Research and Development Program of Ministry of Science and Technology (No. 2017YFC0108900)+1 种基金the Shanghai Municipal Education Commission—Gaofeng Clinical Medicine Grant Support—Gainers from Shanghai Jiao Tong University School of Medicine (No. 20152230)the Emerging Frontier Technology Joint Research Program of Shanghai Shen-Kang Hospital Development Center (No. SHDC2017127)。
文摘Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is an emerging, non-invasive hyperthermia technology which can be used for the treatment of benign and malignant tumours, in conjunction with intracranial neurological diseases. To treat different indications, it is often necessary to design special focused ultrasound devices and treatment plans, which poses great challenges and results in substantial costs during software development. This article introduces a general software architecture that can be applied to three different focused ultrasound devices for the treatment of uterine fibroids, breast fibroids, and pain palliation of bone metastases, respectively, and can be integrated with GE Discovery or Signa MRI scanners and Xingaoyi BroadScan MRI scanners. Finally, the proposed software architecture was shown to possess desirable universality and safety through various tests and animal experimental studies.
文摘Background: The unaesthetic appearance of the female intimate area (vulva, “mound of venus” and perianal region) is a triggering factor of negative psychological responses, embarrassment, anxiety and insecurity in many women. Using rejuvenating equipment for vaginal structure or for the intimate area as a whole is already widespread in the literature, and High-Intensity Focused Ultrasound (HIFU) has proven to be very effective in the clinical practice of many professionals. This study, therefore, aims to describe the fundamentals and applicability that guide the use of HIFU in vulvar rejuvenation. Materials and Methods: Exploratory research was carried out, presented in a narrative review, to highlight the action of HIFU in female intimate rejuvenation. The review explored scientific articles published and available in the following databases: MEDLINE (Medical Literature Analysis and Retrieval System Online), PubMed (National Library of Medicine), SCIELO (Scientific Electronic Library Online), and LILACS (Latin Literature American and the Caribbean in Health Sciences). In addition, some clinical findings obtained through a retrospective analysis of medical records were added to describe the authors’ clinical experience in the use of Focused Ultrasound (HIFU) for vulvar rejuvenation. Results: We verified that the tissues of female external genitalia respond very well to the stimuli of the focused sound waves of the HIFU, being able to produce immediate and lasting results through isolated applications or in association with intradermotherapy or other therapeutic resources. Conclusion: We conclude that using High Intensity Focused Ultrasound aimed at vulvar rejuvenation is safely indicated and assures excellent aesthetic results at the end of the treatment because similarly to other treatment techniques, the thermal stimuli of HIFU are also able to produce an excellent therapeutic response in the dermal tissue of the female intimate area, promoting intense neocollagenesis and generating great aesthetic improvement.
文摘AIM:To analyze whether high-intensity focused ultrasound(HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma(HCC).METHODS:From January 2007 to December 2010,49 consecutive HCC patients were listed for liver transplantation(UCSF criteria).The median waiting time for transplantation was 9.5 mo.Twenty-nine patients received transarterial chemoembolization(TACE) as a bringing therapy and 16 patients received no treatment before transplantation.Five patients received HIFU ablation as a bridging therapy.Another five patients with the same tumor staging(within the UCSF criteria) who received HIFU ablation but not on the transplant list were included for comparison.Patients were comparable in terms of Child-Pugh and model for end-stage liver disease scores,tumor size and number,and cause of cirrhosis.RESULTS:The HIFU group and TACE group showed no difference in terms of tumor size and tumor number.One patient in the HIFU group and no patient in the TACE group had gross ascites.The median hospital stay was 1 d(range,1-21 d) in the TACE group and two days(range,1-9 d) in the HIFU group(P < 0.000).No HIFU-related complication occurred.In the HIFU group,nine patients(90%) had complete response and one patient(10%) had partial response to the treatment.In the TACE group,only one patient(3%) had response to the treatment while 14 patients(48%) had stable disease and 14 patients(48%) had progressive disease(P = 0.00).Seven patients in the TACE group and no patient in the HIFU group dropped out from the transplant waiting list(P = 0.559).CONCLUSION:HIFU ablation is safe and effective in the treatment of HCC for patients with advanced cirrhosis.It may reduce the drop-out rate of liver transplant candidate.
文摘Recent advances in high intensity focused ultrasound(HIFU),which was developed in the 1940s as a viable thermal tissue ablation approach,have increased its popularity.In clinics,HIFU has been applied to treat a variety of solid malignant tumors in a well-defined volume,including the pancreas,liver,prostate,breast,uterine fibroids,and soft-tissue sarcomas.In comparison to conventional tumor/cancer treatment modalities,such as open surgery,radio-and chemo-therapy,HIFU has the advantages of non-invasion,non-ionization,and fewer complications after treatment.Over 100 000 cases have been treated throughout the world with great success.The fundamental principles of HIFU ablation are coagulative thermal necrosis due to the absorption of ultrasound energy during transmission in tissue and the induced cavitation damage.This paper reviews the clinical outcomes of HIFU ablation for applicable cancers,and then summarizes the recommendations for a satisfactory HIFU treatment according to clinical experience.In addition,the current challenges in HIFU for engineers and physicians are also included.More recent horizons have broadened the application of HIFU in tumor treatment,such as HIFU-mediated drug delivery,vessel occlusion,and soft tissue erosion(“histotripsy”).In summary,HIFU is likely to play a significant role in the future oncology practice.
文摘AIM： To analyze the local and systemic complications of high intensity focused ultrasound （HIFU） for patients with recurrent and metastatic abdominal tumors. METHODS： From Aug 2001 to Aug 2004, 17 patients with recurrent and metastatic abdominal tumors were enrolled in this study. Real-time sonography was taken, and vital signs, liver and kidney function, skin burns, local reactions, and systemic effects were observed and recored before, during, and after HIFU. CT and MR/were also taken before and after HIFU. RESULTS： All 17 patients had skin burns and pain in the treatment region; the next common complication was neurapraxia of the stomach and intestines to variable degrees. The other local and systemic complications were relatively rare. Severe complications were present in two patients; one developed a superior mesenteric artery infarction resulting in necrosis of the entire small intestines, and the other one suffered from a perforation in terminal ileum due to HIFU treatment. CONCLUSION： Although HIFU is a one of noninvasive treatments for the recurrent and metastatic abdominal tumors, there are still some common and severe complications which need serious consideration.
基金Supported by The Foundation of Ministry of Education of China,No.IRT0454
文摘AIM:To investigate whether tumor debris created by high-intensity focused ultrasound(HIFU)could trigger antitumor immunity in a mouse hepatocellular carcinoma model. METHODS:Twenty C57BL/6J mice bearing H22 hepatocellular carcinoma were used to generate antitumor vaccines.Ten mice underwent HIFU ablation,and the remaining 10 mice received a sham-HIFU procedure with no ultrasound irradiation.Sixty normal mice were randomly divided into HIFU vaccine,tumor vaccine and control groups.These mice were immunized with HIFU-generated vaccine,tumor-generated vaccine,and saline,respectively.In addition,20 mice bearing H22 tumors were successfully treated with HIFU ablation. The protective immunity of the vaccinated mice was investigated before and after a subsequent H22 tumor challenge.Using the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay,the cytotoxicity of splenic lymphocytes co-cultured with H22 cells wasdetermined in vitro before the tumor challenge,and tumor volume and survival were measured in vivo after the challenge in each group.The mechanism was also explored by loading the vaccines with bone marrowderived dendritic cells(DCs). RESULTS:Compared to the control,HIFU therapy, tumor-generated and HIFU-generated vaccines significantly increased cytolytic activity against H22 cells in the splenocytes of the vaccinated mice(P<0.001). The tumor volume was significantly smaller in the HIFU vaccine group than in the tumor vaccine group(P <0.05)and control group(P<0.01).However,there was no tumor growth after H22 rechallenge in the HIFU therapy group.Forty-eight-day survival rate was 100%in mice in the HIFU therapy group,30%in both the HIFU vaccine and tumor vaccine groups,and 20% in the control group,indicating that the HIFU-treated mice displayed significantly longer survival than the vaccinated mice in the remaining three groups(P< 0.001).After bone marrow-derived DCs were incubated with HIFU-generated and tumor-generated vaccines, the number of mature DCs expressing MHC-Ⅱ + ,CD80 + and CD86 + molecules was significantly increased,and interleukin-12 and interferon-γlevels were significantly higher in the supernatants when compared with immature DCs incubated with mouse serum(P<0.001). However,no differences of the number of mature DCs and cytokine levels were observed between the HIFU- generated and tumor-generated vaccines(P>0.05). CONCLUSION:Tumor debris remaining after HIFU can improve tumor immunogenicity.This debris releases tumor antigens as an effective vaccine to develop host antitumor immune response after HIFU ablation.
基金Supported by the National Natural Science Foundation of China (Nos.40930845 and 41006031)the International Science & Technology Cooperation Program of China (No. 2010DFA21740)the National Science and Technology Major Project (No. 2011ZX05026-004-06)
文摘The origin and migration of natural gas and the accumulation of gas hydrates within the Pearl River Mouth Basin of the northern South China Sea are poorly understood. Based on high-resolution 2D/3D seismic data, three environments of focused fluid flow： gas chimneys, mud diapirs and active faults have been identified. Widespread gas chimneys that act as important conduits for fluid flow are located below bottom simulating reflections and above basal uplifts. The occurrence and evolution of gas chimneys can be divided into a violent eruptive stage and a quiet seepage stage. For most gas chimneys, the strong eruptions are deduced to have happened during the Dongsha Movement in the latest Miocene, which are observed below Pliocene strata and few active faults develop above the top of the Miocene. The formation pressures of the Baiyun Sag currently are considered to be normal, based on these terms： 1） Borehole pressure tests with pressure coefficients of 1.043-l.047; 2） The distribution of gas chimneys is limited to strata older than the Pliocene; 3） Disseminated methane hydrates, rather than fractured hydrates, are found in the hydrate samples; 4） The gas hydrate is mainly charged with biogenic gas rather than thermogenic gas based on the chemical tests from gas hydrates cores. However, periods of quiet focused fluid flow also enable the establishment of good conduits for the migration of abundant biogenic gas and lesser volumes ofthermogenic gas. A geological model goveming fluid flow has been proposed to interpret the release of overpressure, the migration of fluids and the formation of gas hydrates, in an integrated manner. This model suggests that gas chimneys positioned above basal uplifts were caused by the Dongsha Movement at about 5.5 Ma. Biogenic gas occupies the strata above the base of the middle Miocene and migrates slowly into the gas chimney columns. Some of the biogenic gas and small volumes ofthermogenic gas eventually contribute to the formation of the gas hydrates.
文摘High-intensity focused ultrasound(HIFU)is a noninvasive modality that uses an extracorporeal source of focused ultrasound energy.This technique was introduced by Lynn et al and is able to induce coagulative necrosis in selected tissues without damaging adjacent structures.Although HIFU has been studied for 50years,recent technological developments now allow its use for tumours of the liver,prostate and other sites.In liver disease,HIFU has been used to treat unresectable,advanced stages of hepatocellular carcinoma(HCC)and liver metastases.Hepatocellular carcinoma is a serious health problem worldwide and is endemic in some areas because of its association with hepatitis B and C viruses(in 20%of cases).Liver transplantation(LT)has become one of the best treatments available because it removes both the tumour and the underlying liver disease such as cirrhosis(which is present in approximately 80%of cases).The prerequisite for longterm transplant success depends on tumour load and strict selection criteria regarding the size and number of tumour nodules.The need to obtain the optimal benefit from the limited number of organs available has prompted strict selection criteria limited to only those patients with early HCC who have a better long-term outcome after LT.The so-called"bridging therapy"has the aim of controlling disease burden for patients who are on the organ transplant waiting list.Amongst various treatment options,transarterial chemoembolisation and radiofrequency ablation are the most popular treatment choices.Recently,Cheung et al demonstrated that HIFU ablation is a safe and effective method for the treatment of HCC patients with advanced cirrhosis as a bridging therapy and that it reduced the dropout rate from the liver transplant waiting list.In this commentary,we discuss the current value of HIFU in the treatment of liver disease,including its value as a bridging therapy,and examine the potential advantages of other therapeutic strategies.
基金Supported by The cancer research project group of Tokyo Medical University
文摘AIM:To evaluate the safety and clinical application of high-intensity focused ultrasound(HIFU)therapy for unresectable pancreatic cancer(PC).METHODS:Thirty PC patients(16 cases in stage III and 14 cases in stage IV)with visualized pancreatic tumors were admitted for HIFU therapy as an optional local therapy in addition to systemic chemotherapy or chemoradiotherapy.Informed consent was obtained.This study began at the end of 2008 and was approved by the ethics committee of our hospital[Institutional Review Board(IRB):890].The HIFU device used was the FEP-BY02(Yuande Bio-Medical Engineering,Beijing,China).RESULTS:The mean tumor size after HIFU therapy changed to 30.9±1.7 mm from 31.7±1.7 mm at pre-therapy.There were no significant changes in tumor size,mean number of treatment sessions(2.7±0.1 mm),or mean total treatment time(2.4±0.1 h).The rate of symptom relief effect was 66.7%.The effectiveness of primary lesion treatment was as follows:complete response,0;partial response,4;stable disease,22;progressive disease,4.Treatment after HIFU therapy included 2 operations,24 chemotherapy treatments,and 4 best supportive care treatments.Adverse events occurred in 10%of cases,namely pseudocyst formation in 2 cases and mild pancreatitis development in 1.However,no severe adverse events occurred in this study.CONCLUSION:We suggest that HIFU therapy is safe and has the potential to be a new method of combination therapy for PC.
基金supported by grants from the Ministry of Health Research Foundation(WKJ2006-1-007)the Hunan Provincial National Science Foundation (11JJ5060)
文摘BACKGROUND: High-intensity focused ultrasound (HIFU) is a non-invasive method of solid tissue ablation therapy. However, only a few studies have reported the effect of HIFU for unresectable pancreatic cancer. This study aimed to evaluate the clinical benefits, survival time and complications associated with the use of HIFU ablation in patients with unresectable pancreatic cancer. METHODS: Twenty-five patients with unresectable pancreatic cancer were enrolled in our study. All patients received HIFU therapy for tumors at least once. The therapeutic effects of HIFU was evaluated in terms of Karnofsky performance status (KPS) scores, pain relief, serum CA19-9, and imaging by B-US and CT before and after the therapy. We also recorded median overall survival time and complications caused by the treatment. RESULTS: In the 25 patients, KPS scores were above 60, and increased KPS was observed in 23 patients after treatment. Pain relief occurred in 23 patients. Serum CA19-9 levels were significantly reduced one month after HIFU treatment and became negative in 5 patients. B-US revealed enhanced tumor echogenicity in 13 patients and decreased tumor blood supply in 9. Tumor necrosis was confirmed by CT in 8 patients one month after HIFU treatment. The median overall survival time was 10 months, and the 1-year survival rate was 42%. No severe complications were observed after HIFU treatment. CONCLUSION: HIFU can effectively relieve pain, increase KPS, decrease tumor growth and prolong the survival time of patients with unresectable pancreatic cancer.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51309050 and 51221961)the National Basic Research Program of China(973 Program,Grant Nos.2013CB036101 and 2011CB013703)
文摘In this paper, a numerical model is developed based on the High Order Spectral （HOS） method with a non-periodic boundary. A wave maker boundary condition is introduced to simulate wave generation at the incident boundary in the HOS method. Based on the numerical model, the effects of wave parameters, such as the assumed focused amplitude, the central frequency, the frequency bandwidth, the wave amplitude distribution and the directional spreading on the surface elevation of the focused wave, the maximum generated wave crest, and the shifting of the focusing point, are numerically investigated. Especially, the effects of the wave directionality on the focused wave properties are emphasized. The numerical results show that the shifting of the focusing point and the maximum crest of the wave group are dependent on the amplitude of the focused wave, the central frequency, and the wave amplitude distribution type. The wave directionality has a definite effect on multidirectional focused waves. Generally, it can even out the difference between the simulated wave amplitude and the amplitude expected from theory and reduce the shifting of the focusing points, implying that the higher order interaction has an influence on wave focusing, especially for 2D wave. In 3D wave groups, a broader directional spreading weakens the higher nonlinear interactions.
