Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or force...Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or forceps to save the newborn. The purpose of this study was to determine the prevalence of vacuum-assisted vaginal delivery (VAVD) and its associated short-term maternal and neonatal outcomes at Ndola Teaching Hospital. Methods: A retrospective cross-sectional descriptive study through the analysis of routine data for women with singleton-term pregnancies who delivered by vacuum compared with spontaneous vaginal delivery was done at a tertiary hospital for the years 2020 and 2021. Chi-square and Logistic regression were used to investigate factors of vacuum delivery and to adjust for potential confounders. Results: Results showed that VAVD was mostly performed in women who had delayed second stage of labour (25.4%), maternal exhaustion (16.0%), foetal distress in the second stage of labour (12.3%). The overall VAVD prevalence was 3.7% (581/15591). Logistic regression showed that multiparous women were noted to be 87.5% (aOR 0.125;95% CI 0.025 - 0.629;p = 0.012) less likely to undergo VAVD compared to nulliparous women. Registrars were almost 6 times (aOR 5.650;95% CI 1.458 - 22.222, p = 0.012) more likely to conduct VAVD compared to midwives. Episiotomy was 3 times (aOR 3.390;95% CI 1.185 - 9.524;p Conclusion: The findings indicate the underutilisation of VAVD at NTH based on the low prevalence of 3.7%. VAVD outcomes were affected by multiparity, skill level and Episiotomy procedure, in addition, VAVD influenced admission to the NICU. Hence, there is a need to increase skills in VAVD among first-line healthcare workers such as midwives and intern doctors.展开更多
Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses recei...Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses received excisional biopsy with ultrasoundguided vacuum-assisted system.The pathology of patients,results of hematoma development and outcome,influence factors for hematoma occurrence(nodule size,nodule location,number of nodule,breast shape,menstrual period,efficacy time of bandage,and application of hemostatic agents during the procedure) were recorded.Results Pathologic examination revealed fibroadenomas in 138 lesions,fibroadenosis in 127 lesions,intraductal papillomas in 39 lesions,inflammatory change in 4 lesions,retention cyst of the breast in 3 lesions,and benign phyllodes tumor in 1 lesion.Thirty hematomas were observed in patients(9.6%).Finally,97.0%hematomas were absorbed completely within 6 months follow-up.The incidence rates of hematoma were increased by 24.7%,10.0%,63.2%,13.9%in the nodule diameter larger or equal to 25 mm group,removal of larger or equal to two nodules once time from one patient group,menstrual period group,and larger and loose breast group,respectively(all P<0.05).However,the incidences were decreased by 60.6%in the bandage performed for 12-24 hours or beyond 24 hours group(P<0.05).The multiple logistic regression models revealed that nodule size(x^2=15.227,P<0.001),number of nodule(x^2=7.767,P=0.005),menstrual period(x^2=24.530,P<0.001),and breast shape(x^2=9.559,P=0.002) were independent risk factors associated with hematoma occurrence,but efficacy time of bandage was a protective factor associated with hematoma occurrence.Conclusion The occurrence of hematoma after the minimally invasive operation was associated with nodule size,number of nodule,menstrual period,breast shape,and efficacy time of bandage.展开更多
Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentine...Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentinel lymph node biopsy （SLNB） should be performed in patients with an initial diagnosis of DCIS. Methods： A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results： Eighty-two patients （66.1%） had pure DCIS and 25 （20.2%） had DCIS with microinvasion （DCISM）, 17 （13.7%） updated to invasive breast cancer （IBC）. 115 patients （92.7%） underwent SLNB, among them, 70 patients （56.5%） underwent axillary node dissection. 3 of 115 patients （2.6%） had a positive sentinel lymph node, only 1 （1.4%） of 70 patients had axillary lymph node metastasis, in 84 patients （66.7%） who were diagnosed DCIS by core needle biopsy （CNB） and vacuum-assisted biopsy （VAB）. 26 patients （31.0%） were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion： The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients.展开更多
The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common elec...The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common electron transport layer(ETL) needs to be annealed for improving the optoelectronic properties,while conventional flexible substrates could barely stand the high temperature. Herein, a vacuumassisted annealing SnO_(2) ETL at low temperature(100℃) is utilized in flexible PSCs and achieved high efficiency of 20.14%. Meanwhile, the open-circuit voltage(V_(oc)) increases from 1.07 V to 1.14 V. The flexible PSCs also show robust bending stability with 86.8% of the initial efficiency is retained after 1000 bending cycles at a bending radius of 5 mm. X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), and contact angle measurements show that the density of oxygen vacancies, the surface roughness of the SnO_(2) layer, and film hydrophobicity are significantly increased, respectively. These improvements could be due to the oxygen-deficient environment in a vacuum chamber, and the rapid evaporation of solvents. The proposed vacuum-assisted low-temperature annealing method not only improves the efficiency of flexible PSCs but is also compatible and promising in the large-scale commercialization of flexible PSCs.展开更多
BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And mo...BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective treatment for diabetic foot that can significantly improve limb salvage rates.The use of VAC after ER simplifies and facilitates wound repair.展开更多
Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide...Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide treatment planning. This technique has been used in our institute since 2000 and two new wireless handheld ultrasound-guided VABB de- vices have been introduced since May 2012. In this report we analyze our experience with these revolutionary devices which are able to provide the option of single-insertion contiguous tissue samples respectively with a 13/14-gauge aperture. Our initial experience on 75 lesions shows that these devices are safe, fast, procedurally advantageous for operators and well accepted by patients. Finally VABB procedures can markedly reduce the need for surgical biopsy.展开更多
Non-metallic inclusions and zyglo indications frequently occur in the superalloy castings produced through the traditional vacuum gravity investment casting process,particularly in components with thin-walled and comp...Non-metallic inclusions and zyglo indications frequently occur in the superalloy castings produced through the traditional vacuum gravity investment casting process,particularly in components with thin-walled and complex structural features.The vacuum-assisted low-pressure casting(VLC),a type of counter-gravity casting(CGC)method,has been developed to minimize non-metallic inclusions and zyglo indications in superalloy castings.Rectifying frames for gas turbines made from K446 alloy were produced semi-continuously using the VLC process and subsequently evaluated through tensile testing,chemical composition analysis,X-ray diffraction,and zyglo penetrant inspection.The results indicate a roughly 10%improvement in tensile strength at 800℃ compared to gravity casting.Moreover,no significant changes are observed in the chemical composition of the alloys from the beginning to the end of a casting campaign,indicating that the developed VLC process is viable for the engineering-scale production of superalloy castings.Compared to traditional vacuum gravity casting(GC)method,the application of VLC can reduce the numbers of non-metallic inclusions and Zyglo indications in the castings by over 80%.At the same time,it significantly shortens the production time by 3 to 5 days.展开更多
Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a...Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites.The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated.The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure.Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite trend.When the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 MPa.This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size.展开更多
Objective To compare and evaluate the efficacy of diagnosis and excision for appropriately selected breast multi-focal lesions and solitary lesion by ultrasound-guided vacuum-assisted biopsy(UGVAB).Methods Among 392 a...Objective To compare and evaluate the efficacy of diagnosis and excision for appropriately selected breast multi-focal lesions and solitary lesion by ultrasound-guided vacuum-assisted biopsy(UGVAB).Methods Among 392 appropriately selected patients,187 patients with multi-focal lesions and 205 patients with solitary lesion were treated by the 8-gauge UGVAB from May 2007 to June 2009.All lesions were removed as completely as possible.The patients with benign pathology underwent physical and ultrasound examinations at one week and 6 months after procedure.Results During the procedure,only three patients had vasovagal syncope and twenty others complained of other intraoperative discomfort.An accurate pathological diagnosis was obtained in all lesions.There was no apparent false-negative result among the 696 lesions with benign pathology at a follow-up of 6 months after procedure.The rates of malignant or premalignant pathology,postoperative complications and residual lesions in patients with multi-focal lesions were higher than those in patients with solitary lesion.If each lesion was considered as a subject of study,there was no significant difference between the two groups.Conclusion UGVAB is an effective method for diagnosis and excision of appropriately selected breast multi-focal lesions and can be used routinely.展开更多
Objective:To evaluate the safety and effectiveness of vacuum-assisted excision for benign intraductal papilloma of breast.Methods:The databases including PubMed,Embase,Cochrane Library,WangFang,CNIK,VIP and Web of Sci...Objective:To evaluate the safety and effectiveness of vacuum-assisted excision for benign intraductal papilloma of breast.Methods:The databases including PubMed,Embase,Cochrane Library,WangFang,CNIK,VIP and Web of Science were searched by computer,according the inclusion and exclusion criteria after screening of literature.The Cochrane handbook and Newcastle-Ottawa scale was used to evaluate the studies.Then the Review Manager 5.3 software was to used analyze the data.Results:A total of 1016 patients was included in 9 articles.The amount of blood loss in vacuum-assisted surgery was less than that in open surgery[MD=-6.38,95%CI(-9.90,-2.86),P<0.05].The drainage[MD=-2.56,95%CI(-4.97,-0.15,P<0.05]and drainage time[MD=-0.25,95%CI(-0.40,-0.09),P<0.05]in vacuum-assisted surgery was less than that in open surgery.There were also few postoperative complications than that in open surgery[RR=0.43,95%CI(0.29,0.64),P<0.05].Compared with open surgery,the postoperative recurrence rate was lower in vacuum-assisted surgery[RR=0.26,95%CI(0.14,0.49),P<0.05].Last,there was no statistically significant difference in the operative time between vacuum-assisted surgery and open surgery,[SD=-12.82,95%CI(-25.70,0.06),P=0.05].Conclusion:Compared with open surgery,vacuum-assisted excision has the advantages of less blood loss and lower postoperative complications,but the operative time is not statistically significant compared with open surgery.In addition,compared with open surgery in this study,vacuum-assisted excision has the advantages of lower recurrence rate,but it still needs long-term dynamic observation.展开更多
Objective： The objective of this study was to compare the underestimation rate of invasive carcinoma cases with ductal carcinoma in situ （DCIS） at percutaneous ultrasound-guided core biopsies of breast lesions betw...Objective： The objective of this study was to compare the underestimation rate of invasive carcinoma cases with ductal carcinoma in situ （DCIS） at percutaneous ultrasound-guided core biopsies of breast lesions between 14-gauge automated core needle biopsy （ACNB） and 11-gauge vacuum-assisted biopsy （VAB）, and analyze the diagnostic advantages and insufficiencies in DCIS between this two methods, and to determine the relationship between the lesion type （masses or microcalcifications on radiological findings ） and DCIS underestimation rate. Methods： We collected 152 breast lesions which were diagnosed as DCIS by retrospectively reviewing data about ultrasound-guided biopsies of breast lesions （from February 2003 to July 2010）. There were 98 lesions in 95 patients by 14-gauge ACNB, and 54 lesions in 52 patients by 11-gauge VAB （The system used in this study called Mammatome, MMT）. The clinical and radiological findings were reviewed; meanwhile all the selected patients had histological results of the biopsies and follow-up surgeries which also achieved the reliable pathological results to compare with the biopsy results. The differences between two correlated histological results defined as underestimation, and the histological DCIS underestimation rates were compared between the two groups. According to the radiological characteristics, each group was classified into two subgroups （masses or micrecalcifications group）, and the differences between subgroups were also analyzed. Results： The DCIS underestimation rate was 45.9% （45/98） for 14-gauge ACNB and 16.6% （9/54） for MMT. According to the lesion type on ultrasonography, DCIS underestimation was 31.0% （26/84） in masses （43.1% using ACNB and 12.1% using MMT; P = 0.003） and 42.6% （29/68） in microcalcifications （48.9% using ACNB and 23,8% using MMT; P = 0,036）, Conclusion： The underestimation rate of invasive carcinoma in cases with DCIS at ultrasound-guided core biopsies is significantly higher for ACNB than for MMT. Furthermore, this difference does not alter among the two lesion types presented on ultrasonography. So ultrasound-guided VAB （MMT system） could be an effective and useful method for the diagnosis of DCIS lesions no matter what the lesion type is.展开更多
Background: Ultrasound-guided, vacuum-assisted excision [UGVAE] of fibroadenomas is an emerging minimally invasive procedure. UGVAE is being increasingly employed by breast radiologists and surgeons. It has been appro...Background: Ultrasound-guided, vacuum-assisted excision [UGVAE] of fibroadenomas is an emerging minimally invasive procedure. UGVAE is being increasingly employed by breast radiologists and surgeons. It has been approved for this use since 2006 by the National Institute for Health and Clinical Excellence in the UK. The aim of this systematic review is to evaluate the efficacy and safety of this procedure based on the up to date available evidence. Methods: A comprehensive literature search of the Cochrane library, Medline, Embase, PubMed, Google scholar, Trip-database, Internet, and the reference lists of relevant articles was performed. We searched for literature with sizeable cases of therapeutic vacuum-assisted excision of fibroadenomas. All prospective studies with more than 20 study participants were screened. The study quality was assessed using the Grading of Recommendations Assessment, Development, and Evaluation [GRADE] approach. All were in English. Results: Of the four case series that fulfilled the inclusion criteria there were 516 patients in which 520 procedures were performed. Overall complete excision rate was 89.4%. In two of the studies, this was 100% when the lesions were less than 1.5 cm but reduced to 61% when between 1.5 and 2 cm. Most common significant complication was bleeding with 2 cases of pneumothorax. None of the studies can be regarded as high quality going by GRADE approach. Conclusion: Within the limit of the current published case series, UGVAE appears to be an effective and safe procedure for excision of small fibroadenomas of less than 15 mm in size. A well designed case control study or randomized controlled trials with a sufficient sample size is needed to further assess its safety, effectiveness and more importantly, patients’ satisfaction especially in larger sized fibroadenomas.展开更多
Objectives:To compare the effectiveness of vacuum-assisted closure(VAC)against traditional drainage technique,using a retrospective case-control study design,in terms of managing deep neck infections(DNIs).Methods:Pat...Objectives:To compare the effectiveness of vacuum-assisted closure(VAC)against traditional drainage technique,using a retrospective case-control study design,in terms of managing deep neck infections(DNIs).Methods:Patients presenting to Peking Union Medical College Hospital diagnosed with DNIs were recruited in this study.We analyzed the clinical characteristics of DNI patients and divided them into(a)VAC placement group(26 cases)and(b)traditional drainage group(57 cases)according to whether VAC was placed.The differences in length of stay(LOS),wound healing time,and debridement frequency were compared between the two groups.Results:Eighty-three patients had multiple-space infections,i.e.infection at two or more sites.The debridement frequency of the VAC group was significantly lower than that of the traditional drainage group(p=0.001).The wound healing time of the traditional drainage group and VAC group was 38 days(a range of 13-98 days)and 40 days(a range of 11-106 days),respectively;the average LOS was 15 days(a range of 2-68 days)and 16 days(a range of 4-35 days),respectively;and the debridement frequencies were one time(a range of 0-3 times)and zero times(a range of 0-2 times),respectively.The two groups did not differ significantly in wound healing time and hospitalization duration(p=0.319 and 0.937).Conclusions:VAC treatment of DNIs has significant advantages in reducing the frequency of debridement and patient suffering,but it does not show significant advantages in wound healing.Randomized trials are still needed to demonstrate its efficacy.展开更多
Background:Ultrasound‑guided vacuum-assisted excision(UGVAE)and breast biopsy are widely used for the diagnosis and treatment of both benign and suspicious breast lesions.In this retrospective study,we aimed to determ...Background:Ultrasound‑guided vacuum-assisted excision(UGVAE)and breast biopsy are widely used for the diagnosis and treatment of both benign and suspicious breast lesions.In this retrospective study,we aimed to determine the safety of UGVAE for benign breast lesions and provide guidance for clinical practice.Methods:We analyzed clinical and pathological data of female patients who had undergone UGVAE between January 2015 and December 2017 at our institution.All breast lesions were categorized according to the Breast Imaging Reporting and Data System(BI-RADS)before performing UGVAE.Results:In our study cohort,UGVAE was used to resect 10,378 breast lesions from 5789 patients,and selected clinical and histopathological data were analyzed.The most common adverse events were postoperative bleeding(0.24%)and skin hypersensitivity(0.67%).The residual lesion rate was 2.27%.Fibroadenomas accounted for most of the benign lesions(7932 of 10,193;77.82%).Breast cancer was diagnosed in 150 lesions from 128 patients.Multivariable binary logistic regression analyses showed that older age(odds ratio[OR]=2.034,95%confidence interval[CI]:1.668–2.480,p<0.001),higher BI-RADS category(OR=9.514,95%CI:6.790–13.332,p<0.001),and larger legion size(OR=1.048,95%CI:1.019–1.077,p=0.001)were associated with an increased likelihood of breast cancer.Ninety-six patients with breast cancer had undergone follow-up treatment,achieving a 3-year disease-free survival rate of 97.2%and a 3-year overall survival rate of 100%.Conclusions:UGVAE is a safe and effective means of removing benign breast lesions,causing minimal postoperative trauma and fewer complications compared with open surgery.Moreover,UGVAE had little impact on the follow-up treatment and survival of patients diagnosed with breast cancer.展开更多
Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coati...Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coating technique. MIS trench capacitors with diameter of-6 μm and depth of-54 μm were successfully fabricated with polyimide insulator step coverage better than 30%. C-V characteristics and leakage current properties of the MIS trench capacitor were evaluated under thermal treat- ment. Experimental results show that, the minimum capacitance density is around 4.82 nF/cm2, and the leakage current density after 30 cycles of thermal chock tests becomes stable and it is around 30 nA/cm2 under bias voltage of 20 V. It also shows that, the polyimide dielectric liner is with an excellent capability in constraining copper ion diffusion and mobile charges even un- der test temperature as high as 125℃. Finite element analysis results show that TSVs with polyimide dielectric liner are with lower risks in SiO2 interlayer dielectric （ILD） fracture and interfacial delamination along dielectric-silicon interface, thus, higher thermo-mechanical reliability can be expected.展开更多
Carbon-fiber-reinforced plastics(CFRP)with improved mechanical properties based on modified epoxy binders were investigated in this study.By adding 15 parts by weight(p.b.w.)of copolymer of polysulfone with cardo phth...Carbon-fiber-reinforced plastics(CFRP)with improved mechanical properties based on modified epoxy binders were investigated in this study.By adding 15 parts by weight(p.b.w.)of copolymer of polysulfone with cardo phthalide group(PSFP-70C)to the epoxyanhydride binder,the flexural strength of the epoxy polymer was increased by 60%,the CFRP based on it by 57%,the flexural modulus of the epoxy polymer was increased by 83%,and the composite by 96%.The adhesion strength of the binder to carbon fiber reached a high level at 10 p.b.w.of thermoplastic modifier and increased by 65%compared to the unmodified binder.Scanning electron microscopy(SEM)was used to determine that in epoxyanhydride systems with a polysulfone content of 5–15 p.b.w.,the structure belongs to the"matrix dispersion"type and with a content of 20 p.b.w.to the"interpenetrating phase"type.A heterogeneous structure was also observed using dynamic mechanical analysis.展开更多
The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that t...The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that the HPDC under the vacuum could significantly change the morphology and distribution of the microstructure. For both conventional and vacuum-assist HPDC processes, the externally solidified crystals （ESCs） tended to aggregate in the center along the thickness direction of the castings. Besides, the aggregation was more pronounced, and the number of ESCs decreased, and the ESCs tended to become smaller and more globular, as the distance between the specimen location and runner increased. Compared with the conventional castings, the vacuum-assist HPDC can significantly reduce the size and amount of ESCs, and the ESCs tended to be more globular. For the distribution of ESCs along the thickness of the specimens, the aggregation tendency was more pronounced in vacuum-assist die castings than that in conventional castings. Besides, the distribution of ESCs at different locations was more converged in the vacuum-assist HPDC than that in the conventional HPDC.展开更多
There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery...There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery is unrealistic for the vast majority of procedures in neonates or small infants;however,considerable progress has been made by using techniques that decrease the need for homologous blood products or even allow bloodless surgery in older infants and children.These techniques involve a decrease in prime volume by downsizing the bypass circuit with the help of vacuumassisted venous drainage,microplegia,autologous blood predonation with or without infusion of recombinant(erythropoietin),cell salvaging,ultrafiltration and retrograde autologous priming.The three major techniques which are simple,safe,efficient,and cost-effective are:a prime volume as small as possible,cardioplegia with negligible hydric balance and circuit residual blood salvaged without any alteration.Furthermore,these three techniques can be used for all the patients,including emergencies and small babies.In every pediatric surgical unit,a strategy to decrease or avoid blood bank transfusion must be implemented.A strategy to minimize transfusion requirement requires a combined effort involving the entire surgical team with pre-,peri-,and postoperative planning and management.展开更多
Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shieldin...Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shielding materials(i.e.,when the EM wave is incident from different sides of the sample,the EMI shielding effectiveness(SE)is rather different)are strongly required;unfortunately,no comprehensive literature report is available on this research field.Herein,Nicoated melamine foams(Ni@MF)were obtained by a facile electroless plating process,and multiwalled carbon nanotube(CNT)papers were prepared via a simple vacuum-assisted self-assembly approach.Then,step-wise asymmetric poly(butylene adipate-co-terephthalate)(PBAT)composites consisting of loose Ni@MF layer and compact CNT layer were successfully fabricated via a facile solution encapsulation approach.The step-wise asymmetric structures and electrical conductivity endow the Ni@MF/CNT/PBAT composites with unprecedented directional EMI shielding performances.When the EM wave is incident from Ni@MF layer or CNT layer,Ni@MF-5/CNT-75/PBAT exhibits the total EMI SE(SET)of 38.3 and 29.5 dB,respectively,which illustrates theΔSET of 8.8 dB.This work opens a new research window for directional EMI shielding composites with step-wise asymmetric structures,which has promising applications in portable electronics and next-generation communication technologies.展开更多
BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literat...BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literature.Here,we present two cases of breast DCIS arising within a fibroadenoma and discuss their clinical and imaging findings as well as treatment.CASE SUMMARY The patients did not have cancer-related personal and family histories.Case 1(a 49-year-old woman)was diagnosed with a bilateral breast nodule in May 2018 and was followed(preoperative imaging data including ultrasound and mammography)for 3 years;she underwent an excisional biopsy to address an enlargement in nodule size.Case 2(a 37-year-old woman)was diagnosed with a left breast nodule in June 2021 and consequently received vacuum-assisted biopsy of the tumor which appeared as“irregularly shaped”and“unevenly textured”tissue on ultrasound.The pathological diagnosis was clear in both cases.Both patients underwent breast-conserving surgery and sentinel lymph node biopsy.The two cases received or planned to receive radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION Breast DCIS arising within a fibroadenoma is rare,but patients treated with radiotherapy and endocrine therapy can have good prognosis.展开更多
文摘Background: The maternal and neonatal morbidity caused by prolonged labour, maternal exhaustion and other factors push clinicians to speed up the delivery process by employing equipment such as vacuum suction or forceps to save the newborn. The purpose of this study was to determine the prevalence of vacuum-assisted vaginal delivery (VAVD) and its associated short-term maternal and neonatal outcomes at Ndola Teaching Hospital. Methods: A retrospective cross-sectional descriptive study through the analysis of routine data for women with singleton-term pregnancies who delivered by vacuum compared with spontaneous vaginal delivery was done at a tertiary hospital for the years 2020 and 2021. Chi-square and Logistic regression were used to investigate factors of vacuum delivery and to adjust for potential confounders. Results: Results showed that VAVD was mostly performed in women who had delayed second stage of labour (25.4%), maternal exhaustion (16.0%), foetal distress in the second stage of labour (12.3%). The overall VAVD prevalence was 3.7% (581/15591). Logistic regression showed that multiparous women were noted to be 87.5% (aOR 0.125;95% CI 0.025 - 0.629;p = 0.012) less likely to undergo VAVD compared to nulliparous women. Registrars were almost 6 times (aOR 5.650;95% CI 1.458 - 22.222, p = 0.012) more likely to conduct VAVD compared to midwives. Episiotomy was 3 times (aOR 3.390;95% CI 1.185 - 9.524;p Conclusion: The findings indicate the underutilisation of VAVD at NTH based on the low prevalence of 3.7%. VAVD outcomes were affected by multiparity, skill level and Episiotomy procedure, in addition, VAVD influenced admission to the NICU. Hence, there is a need to increase skills in VAVD among first-line healthcare workers such as midwives and intern doctors.
基金Supported by the National Major Scientific Equipment Special Project(2012YQ16020304)
文摘Objective To explore the influence factors in hematoma formation after removing benign breast lesions with an ultrasound-guided vacuum-assisted system.Methods A total of 232 females with 312 benign breast masses received excisional biopsy with ultrasoundguided vacuum-assisted system.The pathology of patients,results of hematoma development and outcome,influence factors for hematoma occurrence(nodule size,nodule location,number of nodule,breast shape,menstrual period,efficacy time of bandage,and application of hemostatic agents during the procedure) were recorded.Results Pathologic examination revealed fibroadenomas in 138 lesions,fibroadenosis in 127 lesions,intraductal papillomas in 39 lesions,inflammatory change in 4 lesions,retention cyst of the breast in 3 lesions,and benign phyllodes tumor in 1 lesion.Thirty hematomas were observed in patients(9.6%).Finally,97.0%hematomas were absorbed completely within 6 months follow-up.The incidence rates of hematoma were increased by 24.7%,10.0%,63.2%,13.9%in the nodule diameter larger or equal to 25 mm group,removal of larger or equal to two nodules once time from one patient group,menstrual period group,and larger and loose breast group,respectively(all P<0.05).However,the incidences were decreased by 60.6%in the bandage performed for 12-24 hours or beyond 24 hours group(P<0.05).The multiple logistic regression models revealed that nodule size(x^2=15.227,P<0.001),number of nodule(x^2=7.767,P=0.005),menstrual period(x^2=24.530,P<0.001),and breast shape(x^2=9.559,P=0.002) were independent risk factors associated with hematoma occurrence,but efficacy time of bandage was a protective factor associated with hematoma occurrence.Conclusion The occurrence of hematoma after the minimally invasive operation was associated with nodule size,number of nodule,menstrual period,breast shape,and efficacy time of bandage.
文摘Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ （DCIS）. The purpose of this study was to investigate whether sentinel lymph node biopsy （SLNB） should be performed in patients with an initial diagnosis of DCIS. Methods： A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results： Eighty-two patients （66.1%） had pure DCIS and 25 （20.2%） had DCIS with microinvasion （DCISM）, 17 （13.7%） updated to invasive breast cancer （IBC）. 115 patients （92.7%） underwent SLNB, among them, 70 patients （56.5%） underwent axillary node dissection. 3 of 115 patients （2.6%） had a positive sentinel lymph node, only 1 （1.4%） of 70 patients had axillary lymph node metastasis, in 84 patients （66.7%） who were diagnosed DCIS by core needle biopsy （CNB） and vacuum-assisted biopsy （VAB）. 26 patients （31.0%） were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion： The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients.
基金supported by the National Natural Science Foundation of China(61774046)。
文摘The demand for lightweight, flexible, and high-performance portable power sources urgently requires high-efficiency and stable flexible solar cells. In the case of perovskite solar cells(PSCs), most of the common electron transport layer(ETL) needs to be annealed for improving the optoelectronic properties,while conventional flexible substrates could barely stand the high temperature. Herein, a vacuumassisted annealing SnO_(2) ETL at low temperature(100℃) is utilized in flexible PSCs and achieved high efficiency of 20.14%. Meanwhile, the open-circuit voltage(V_(oc)) increases from 1.07 V to 1.14 V. The flexible PSCs also show robust bending stability with 86.8% of the initial efficiency is retained after 1000 bending cycles at a bending radius of 5 mm. X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), and contact angle measurements show that the density of oxygen vacancies, the surface roughness of the SnO_(2) layer, and film hydrophobicity are significantly increased, respectively. These improvements could be due to the oxygen-deficient environment in a vacuum chamber, and the rapid evaporation of solvents. The proposed vacuum-assisted low-temperature annealing method not only improves the efficiency of flexible PSCs but is also compatible and promising in the large-scale commercialization of flexible PSCs.
文摘BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation rates.And most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot patients.AIM To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic foot.METHODS Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April 2022.Diabetic foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity arteries.Continuous subcutaneous insulin infusion pumps were used to achieve glycemic control.Lower limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or stenting.Wounds were cleaned by nibbling debridement.Wound granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap transplantation.RESULTS Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent implantation.In the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old BA.VAC was performed in 32 wounds.Twenty-four cases of skin grafting and 2 cases of skin flap transplantation were performed.Two patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in combination with VAC is a safe and effective treatment for diabetic foot that can significantly improve limb salvage rates.The use of VAC after ER simplifies and facilitates wound repair.
文摘Vacuum-assisted breast biopsy (VABB) plays a fundamental role in the preoperative assessment of breast lesions pro- viding large histology samples that are useful to define diagnoses and biological parameters to guide treatment planning. This technique has been used in our institute since 2000 and two new wireless handheld ultrasound-guided VABB de- vices have been introduced since May 2012. In this report we analyze our experience with these revolutionary devices which are able to provide the option of single-insertion contiguous tissue samples respectively with a 13/14-gauge aperture. Our initial experience on 75 lesions shows that these devices are safe, fast, procedurally advantageous for operators and well accepted by patients. Finally VABB procedures can markedly reduce the need for surgical biopsy.
基金financially supported by the National Key Research and Development Plan Project of the Ministry of Science and Technology:Intelligent Liquid Precision Casting Technology and Application of Large Complex Thin-Wall High-End Metal Components(No.2022YFB3706800).
文摘Non-metallic inclusions and zyglo indications frequently occur in the superalloy castings produced through the traditional vacuum gravity investment casting process,particularly in components with thin-walled and complex structural features.The vacuum-assisted low-pressure casting(VLC),a type of counter-gravity casting(CGC)method,has been developed to minimize non-metallic inclusions and zyglo indications in superalloy castings.Rectifying frames for gas turbines made from K446 alloy were produced semi-continuously using the VLC process and subsequently evaluated through tensile testing,chemical composition analysis,X-ray diffraction,and zyglo penetrant inspection.The results indicate a roughly 10%improvement in tensile strength at 800℃ compared to gravity casting.Moreover,no significant changes are observed in the chemical composition of the alloys from the beginning to the end of a casting campaign,indicating that the developed VLC process is viable for the engineering-scale production of superalloy castings.Compared to traditional vacuum gravity casting(GC)method,the application of VLC can reduce the numbers of non-metallic inclusions and Zyglo indications in the castings by over 80%.At the same time,it significantly shortens the production time by 3 to 5 days.
文摘Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites.The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated.The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure.Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite trend.When the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 MPa.This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size.
文摘Objective To compare and evaluate the efficacy of diagnosis and excision for appropriately selected breast multi-focal lesions and solitary lesion by ultrasound-guided vacuum-assisted biopsy(UGVAB).Methods Among 392 appropriately selected patients,187 patients with multi-focal lesions and 205 patients with solitary lesion were treated by the 8-gauge UGVAB from May 2007 to June 2009.All lesions were removed as completely as possible.The patients with benign pathology underwent physical and ultrasound examinations at one week and 6 months after procedure.Results During the procedure,only three patients had vasovagal syncope and twenty others complained of other intraoperative discomfort.An accurate pathological diagnosis was obtained in all lesions.There was no apparent false-negative result among the 696 lesions with benign pathology at a follow-up of 6 months after procedure.The rates of malignant or premalignant pathology,postoperative complications and residual lesions in patients with multi-focal lesions were higher than those in patients with solitary lesion.If each lesion was considered as a subject of study,there was no significant difference between the two groups.Conclusion UGVAB is an effective method for diagnosis and excision of appropriately selected breast multi-focal lesions and can be used routinely.
基金This study was supported by Key R&D Program of Hainan Province(No.ZDYF2017087)In-Hospital Project of the Second Affiliated Hospital of Hainan Medical University[The Second Affiliated Hospital of Haiyi Medical University(No.2018-11)]。
文摘Objective:To evaluate the safety and effectiveness of vacuum-assisted excision for benign intraductal papilloma of breast.Methods:The databases including PubMed,Embase,Cochrane Library,WangFang,CNIK,VIP and Web of Science were searched by computer,according the inclusion and exclusion criteria after screening of literature.The Cochrane handbook and Newcastle-Ottawa scale was used to evaluate the studies.Then the Review Manager 5.3 software was to used analyze the data.Results:A total of 1016 patients was included in 9 articles.The amount of blood loss in vacuum-assisted surgery was less than that in open surgery[MD=-6.38,95%CI(-9.90,-2.86),P<0.05].The drainage[MD=-2.56,95%CI(-4.97,-0.15,P<0.05]and drainage time[MD=-0.25,95%CI(-0.40,-0.09),P<0.05]in vacuum-assisted surgery was less than that in open surgery.There were also few postoperative complications than that in open surgery[RR=0.43,95%CI(0.29,0.64),P<0.05].Compared with open surgery,the postoperative recurrence rate was lower in vacuum-assisted surgery[RR=0.26,95%CI(0.14,0.49),P<0.05].Last,there was no statistically significant difference in the operative time between vacuum-assisted surgery and open surgery,[SD=-12.82,95%CI(-25.70,0.06),P=0.05].Conclusion:Compared with open surgery,vacuum-assisted excision has the advantages of less blood loss and lower postoperative complications,but the operative time is not statistically significant compared with open surgery.In addition,compared with open surgery in this study,vacuum-assisted excision has the advantages of lower recurrence rate,but it still needs long-term dynamic observation.
文摘Objective： The objective of this study was to compare the underestimation rate of invasive carcinoma cases with ductal carcinoma in situ （DCIS） at percutaneous ultrasound-guided core biopsies of breast lesions between 14-gauge automated core needle biopsy （ACNB） and 11-gauge vacuum-assisted biopsy （VAB）, and analyze the diagnostic advantages and insufficiencies in DCIS between this two methods, and to determine the relationship between the lesion type （masses or microcalcifications on radiological findings ） and DCIS underestimation rate. Methods： We collected 152 breast lesions which were diagnosed as DCIS by retrospectively reviewing data about ultrasound-guided biopsies of breast lesions （from February 2003 to July 2010）. There were 98 lesions in 95 patients by 14-gauge ACNB, and 54 lesions in 52 patients by 11-gauge VAB （The system used in this study called Mammatome, MMT）. The clinical and radiological findings were reviewed; meanwhile all the selected patients had histological results of the biopsies and follow-up surgeries which also achieved the reliable pathological results to compare with the biopsy results. The differences between two correlated histological results defined as underestimation, and the histological DCIS underestimation rates were compared between the two groups. According to the radiological characteristics, each group was classified into two subgroups （masses or micrecalcifications group）, and the differences between subgroups were also analyzed. Results： The DCIS underestimation rate was 45.9% （45/98） for 14-gauge ACNB and 16.6% （9/54） for MMT. According to the lesion type on ultrasonography, DCIS underestimation was 31.0% （26/84） in masses （43.1% using ACNB and 12.1% using MMT; P = 0.003） and 42.6% （29/68） in microcalcifications （48.9% using ACNB and 23,8% using MMT; P = 0,036）, Conclusion： The underestimation rate of invasive carcinoma in cases with DCIS at ultrasound-guided core biopsies is significantly higher for ACNB than for MMT. Furthermore, this difference does not alter among the two lesion types presented on ultrasonography. So ultrasound-guided VAB （MMT system） could be an effective and useful method for the diagnosis of DCIS lesions no matter what the lesion type is.
文摘Background: Ultrasound-guided, vacuum-assisted excision [UGVAE] of fibroadenomas is an emerging minimally invasive procedure. UGVAE is being increasingly employed by breast radiologists and surgeons. It has been approved for this use since 2006 by the National Institute for Health and Clinical Excellence in the UK. The aim of this systematic review is to evaluate the efficacy and safety of this procedure based on the up to date available evidence. Methods: A comprehensive literature search of the Cochrane library, Medline, Embase, PubMed, Google scholar, Trip-database, Internet, and the reference lists of relevant articles was performed. We searched for literature with sizeable cases of therapeutic vacuum-assisted excision of fibroadenomas. All prospective studies with more than 20 study participants were screened. The study quality was assessed using the Grading of Recommendations Assessment, Development, and Evaluation [GRADE] approach. All were in English. Results: Of the four case series that fulfilled the inclusion criteria there were 516 patients in which 520 procedures were performed. Overall complete excision rate was 89.4%. In two of the studies, this was 100% when the lesions were less than 1.5 cm but reduced to 61% when between 1.5 and 2 cm. Most common significant complication was bleeding with 2 cases of pneumothorax. None of the studies can be regarded as high quality going by GRADE approach. Conclusion: Within the limit of the current published case series, UGVAE appears to be an effective and safe procedure for excision of small fibroadenomas of less than 15 mm in size. A well designed case control study or randomized controlled trials with a sufficient sample size is needed to further assess its safety, effectiveness and more importantly, patients’ satisfaction especially in larger sized fibroadenomas.
基金Natural Science Foundation of Beijing Municipality(Grant/Award Number:7192171)Peking Union Medical Foundation,Pumch Healthcare Quality and Safety Incubation Program(Grant/Award Number:XHZJ2411)。
文摘Objectives:To compare the effectiveness of vacuum-assisted closure(VAC)against traditional drainage technique,using a retrospective case-control study design,in terms of managing deep neck infections(DNIs).Methods:Patients presenting to Peking Union Medical College Hospital diagnosed with DNIs were recruited in this study.We analyzed the clinical characteristics of DNI patients and divided them into(a)VAC placement group(26 cases)and(b)traditional drainage group(57 cases)according to whether VAC was placed.The differences in length of stay(LOS),wound healing time,and debridement frequency were compared between the two groups.Results:Eighty-three patients had multiple-space infections,i.e.infection at two or more sites.The debridement frequency of the VAC group was significantly lower than that of the traditional drainage group(p=0.001).The wound healing time of the traditional drainage group and VAC group was 38 days(a range of 13-98 days)and 40 days(a range of 11-106 days),respectively;the average LOS was 15 days(a range of 2-68 days)and 16 days(a range of 4-35 days),respectively;and the debridement frequencies were one time(a range of 0-3 times)and zero times(a range of 0-2 times),respectively.The two groups did not differ significantly in wound healing time and hospitalization duration(p=0.319 and 0.937).Conclusions:VAC treatment of DNIs has significant advantages in reducing the frequency of debridement and patient suffering,but it does not show significant advantages in wound healing.Randomized trials are still needed to demonstrate its efficacy.
基金Military Key Clinical Speciality(Grants:51561Z23612)Chongqing Talent Program Project(Grants:cstc2022ycjh-bgzxm0091)+1 种基金Chongqing Major Medical Research Program(Joint Program of Chongqing Municipal Health Commission and Science and Technology Bureau)(Grants:2024DBXM001)Chongqing Clinical Diagnosis and Treatment Center of Breast Cancer(Grants:425Z2a1).
文摘Background:Ultrasound‑guided vacuum-assisted excision(UGVAE)and breast biopsy are widely used for the diagnosis and treatment of both benign and suspicious breast lesions.In this retrospective study,we aimed to determine the safety of UGVAE for benign breast lesions and provide guidance for clinical practice.Methods:We analyzed clinical and pathological data of female patients who had undergone UGVAE between January 2015 and December 2017 at our institution.All breast lesions were categorized according to the Breast Imaging Reporting and Data System(BI-RADS)before performing UGVAE.Results:In our study cohort,UGVAE was used to resect 10,378 breast lesions from 5789 patients,and selected clinical and histopathological data were analyzed.The most common adverse events were postoperative bleeding(0.24%)and skin hypersensitivity(0.67%).The residual lesion rate was 2.27%.Fibroadenomas accounted for most of the benign lesions(7932 of 10,193;77.82%).Breast cancer was diagnosed in 150 lesions from 128 patients.Multivariable binary logistic regression analyses showed that older age(odds ratio[OR]=2.034,95%confidence interval[CI]:1.668–2.480,p<0.001),higher BI-RADS category(OR=9.514,95%CI:6.790–13.332,p<0.001),and larger legion size(OR=1.048,95%CI:1.019–1.077,p=0.001)were associated with an increased likelihood of breast cancer.Ninety-six patients with breast cancer had undergone follow-up treatment,achieving a 3-year disease-free survival rate of 97.2%and a 3-year overall survival rate of 100%.Conclusions:UGVAE is a safe and effective means of removing benign breast lesions,causing minimal postoperative trauma and fewer complications compared with open surgery.Moreover,UGVAE had little impact on the follow-up treatment and survival of patients diagnosed with breast cancer.
基金supported by the National Natural Science Foundation of China(Grant Nos.61404008&61574016)"111"Project of China(Grant No.B14010)
文摘Low-k and high aspect ratio blind through-silicon-vias （TSVs） to be applied in ＂via-last/backside via＂ 3-D integration paradigm were fabricated with polyimide dielectric liners formed by vacuum-assisted spin coating technique. MIS trench capacitors with diameter of-6 μm and depth of-54 μm were successfully fabricated with polyimide insulator step coverage better than 30%. C-V characteristics and leakage current properties of the MIS trench capacitor were evaluated under thermal treat- ment. Experimental results show that, the minimum capacitance density is around 4.82 nF/cm2, and the leakage current density after 30 cycles of thermal chock tests becomes stable and it is around 30 nA/cm2 under bias voltage of 20 V. It also shows that, the polyimide dielectric liner is with an excellent capability in constraining copper ion diffusion and mobile charges even un- der test temperature as high as 125℃. Finite element analysis results show that TSVs with polyimide dielectric liner are with lower risks in SiO2 interlayer dielectric （ILD） fracture and interfacial delamination along dielectric-silicon interface, thus, higher thermo-mechanical reliability can be expected.
基金financially supported by the Ministry of Science and Higher Education of the Russian Federation。
文摘Carbon-fiber-reinforced plastics(CFRP)with improved mechanical properties based on modified epoxy binders were investigated in this study.By adding 15 parts by weight(p.b.w.)of copolymer of polysulfone with cardo phthalide group(PSFP-70C)to the epoxyanhydride binder,the flexural strength of the epoxy polymer was increased by 60%,the CFRP based on it by 57%,the flexural modulus of the epoxy polymer was increased by 83%,and the composite by 96%.The adhesion strength of the binder to carbon fiber reached a high level at 10 p.b.w.of thermoplastic modifier and increased by 65%compared to the unmodified binder.Scanning electron microscopy(SEM)was used to determine that in epoxyanhydride systems with a polysulfone content of 5–15 p.b.w.,the structure belongs to the"matrix dispersion"type and with a content of 20 p.b.w.to the"interpenetrating phase"type.A heterogeneous structure was also observed using dynamic mechanical analysis.
基金the financial support of the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No. 2012ZX04012011)the National Natural Science Foundation of China(Grant No.51275269)the Independent Research Program of Tsinghua University(Grant No.20121087918)
文摘The structures in vacuum-assist high-pressure die casting （HPDC） AM60B alloy were studied by using an optical microscope and a scanning electron microscope with an energy dispersive spectrometer. It was found that the HPDC under the vacuum could significantly change the morphology and distribution of the microstructure. For both conventional and vacuum-assist HPDC processes, the externally solidified crystals （ESCs） tended to aggregate in the center along the thickness direction of the castings. Besides, the aggregation was more pronounced, and the number of ESCs decreased, and the ESCs tended to become smaller and more globular, as the distance between the specimen location and runner increased. Compared with the conventional castings, the vacuum-assist HPDC can significantly reduce the size and amount of ESCs, and the ESCs tended to be more globular. For the distribution of ESCs along the thickness of the specimens, the aggregation tendency was more pronounced in vacuum-assist die castings than that in conventional castings. Besides, the distribution of ESCs at different locations was more converged in the vacuum-assist HPDC than that in the conventional HPDC.
文摘There is increasing concern about the safety of homologous blood transfusion during cardiac surgery,and a restrictive transfusion practice is associated with improved outcome.Transfusion-free pediatric cardiac surgery is unrealistic for the vast majority of procedures in neonates or small infants;however,considerable progress has been made by using techniques that decrease the need for homologous blood products or even allow bloodless surgery in older infants and children.These techniques involve a decrease in prime volume by downsizing the bypass circuit with the help of vacuumassisted venous drainage,microplegia,autologous blood predonation with or without infusion of recombinant(erythropoietin),cell salvaging,ultrafiltration and retrograde autologous priming.The three major techniques which are simple,safe,efficient,and cost-effective are:a prime volume as small as possible,cardioplegia with negligible hydric balance and circuit residual blood salvaged without any alteration.Furthermore,these three techniques can be used for all the patients,including emergencies and small babies.In every pediatric surgical unit,a strategy to decrease or avoid blood bank transfusion must be implemented.A strategy to minimize transfusion requirement requires a combined effort involving the entire surgical team with pre-,peri-,and postoperative planning and management.
基金Science and Technology Plan Project of Guizhou Province(No.[2019]1084 and[2018]5781)National Natural Science Foundation of China(No.51963003)+3 种基金The Youth Science and Technology Talent Growth Project of Guizhou Province Education Department(No.[2018]106)Outstanding Youth Program of Guizhou Province(No.20170439178)The Key project of Fundamental research in Guizhou province[2020]1Z044Scientific Research Project of Introduced Talents of Guizhou University(No.(2017)07)are acknowledged for the financial support.
文摘Some precision electronics such as signal transmitters need to not only emit effective signal but also be protected from the external electromagnetic(EM)waves.Thus,directional electromagnetic interference(EMI)shielding materials(i.e.,when the EM wave is incident from different sides of the sample,the EMI shielding effectiveness(SE)is rather different)are strongly required;unfortunately,no comprehensive literature report is available on this research field.Herein,Nicoated melamine foams(Ni@MF)were obtained by a facile electroless plating process,and multiwalled carbon nanotube(CNT)papers were prepared via a simple vacuum-assisted self-assembly approach.Then,step-wise asymmetric poly(butylene adipate-co-terephthalate)(PBAT)composites consisting of loose Ni@MF layer and compact CNT layer were successfully fabricated via a facile solution encapsulation approach.The step-wise asymmetric structures and electrical conductivity endow the Ni@MF/CNT/PBAT composites with unprecedented directional EMI shielding performances.When the EM wave is incident from Ni@MF layer or CNT layer,Ni@MF-5/CNT-75/PBAT exhibits the total EMI SE(SET)of 38.3 and 29.5 dB,respectively,which illustrates theΔSET of 8.8 dB.This work opens a new research window for directional EMI shielding composites with step-wise asymmetric structures,which has promising applications in portable electronics and next-generation communication technologies.
文摘BACKGROUND Ductal carcinoma in situ(DCIS)arising within fibroadenoma is a type of tumor that is rarely encountered in clinic,with only about 100 cases of carcinoma arising within a fibroadenoma reported in the literature.Here,we present two cases of breast DCIS arising within a fibroadenoma and discuss their clinical and imaging findings as well as treatment.CASE SUMMARY The patients did not have cancer-related personal and family histories.Case 1(a 49-year-old woman)was diagnosed with a bilateral breast nodule in May 2018 and was followed(preoperative imaging data including ultrasound and mammography)for 3 years;she underwent an excisional biopsy to address an enlargement in nodule size.Case 2(a 37-year-old woman)was diagnosed with a left breast nodule in June 2021 and consequently received vacuum-assisted biopsy of the tumor which appeared as“irregularly shaped”and“unevenly textured”tissue on ultrasound.The pathological diagnosis was clear in both cases.Both patients underwent breast-conserving surgery and sentinel lymph node biopsy.The two cases received or planned to receive radiotherapy as well as endocrine therapy(tamoxifen).CONCLUSION Breast DCIS arising within a fibroadenoma is rare,but patients treated with radiotherapy and endocrine therapy can have good prognosis.
