N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory lo...N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.展开更多
In this editorial,a commentary on the article by Chang et al has been provided,the course of treatment of anorectal fistulas,especially complex and recurring ones,require accurate diagnostic procedures for determining...In this editorial,a commentary on the article by Chang et al has been provided,the course of treatment of anorectal fistulas,especially complex and recurring ones,require accurate diagnostic procedures for determining ideal surgical procedures.Conventional ways of imaging sometimes fall short,offering insufficient insights in aggravated instances.In this editorial,a novel application of hydrogen peroxide-enhanced magnetic resonance imaging(HP-MRI)that promises significant improvements in the imaging of anorectal fistula.Study is based on a retrospective investigation of 60 patients,contrasts the new HP-MRI with conventional diagnostic techniques such as physical examination,trans-perineal ultrasonography and poor spatial resolution MRI.The findings demonstrate HP-MRI's incredible diagnostic performance,with sensitivity and specificity rates of 96.08%and 90.91%,respectively,and unparalleled interobserver agreement(Kappa values ranging from 0.80 to 0.89).It has been a significant advancement for assessment of anorectal fistulas providing a better roadmap for surgical planning,lowering recurrence rates as well as reduced personal and financial burden on patients by reducing the need for repeated treatment and extended hospital stays.The remaining funds can be utilized for treatment of other medical need.Ultimately HP-MRI provides us a healthier&more efficient society by improvising patients well-being&optimized healthcare infrastructure.展开更多
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism....Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.展开更多
The oral cavity is a complex physiological community encompassing a wide range of microorganisms.Dysbiosis of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even...The oral cavity is a complex physiological community encompassing a wide range of microorganisms.Dysbiosis of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative diseases.Recent studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention strategies.In this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and neurodegeneration.We also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.展开更多
BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is defined by the abnormal lipid deposition in hepatocytes.The prevalence of MASLD is significantly increased in the elderly population,suggest...BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is defined by the abnormal lipid deposition in hepatocytes.The prevalence of MASLD is significantly increased in the elderly population,suggesting that aging may be related to the occurrence of MASLD.Emerging evidences suggest that vitamin D receptor(VDR)may be implicated in the progression of MASLD.Therefore,additional researches are warranted to elucidate whether VDR plays a role in aging-related MASLD.AIM To investigate the relationship between aging and MASLD and explore the role and related mechanisms of VDR in aging-related MASLD.METHODS Cellular senescence models were established,and the senescence phenotype of telomerase RNA component knockout mice was validated.These mice were then used as a senescence model for subsequent studies.Changes in VDR expression in the livers of aging mice were examined.VDR knockdown models,including cell knockdown models and hepatic-specific VDR knockout mice,were constructed,and MASLD was established in these models.Additionally,vitamin D(VD)-supplemented models,including senescent liver cell lines and senescent mice,were constructed.RESULTS The steatosis in senescent liver cells was more severe than in normal cells(P<0.05).Moreover,hepatic steatosis was significantly more pronounced in senescence model mice compared to control group when the MASLD model was successfully induced(P<0.05).Therefore,we concluded that aging aggravated hepatic steatosis.The hepatic expression of VDR increased after aging.VDR knockdown in senescent liver cells and senescent mice alleviated hepatic steatosis(P<0.05).When senescent liver cells were stimulated with VD,cellular steatosis was aggravated(P<0.05).However,VD supplementation had no effect on aging mice.CONCLUSION Aging can lead to increased hepatic steatosis,and the hepatic-specific knockdown of VDR alleviated aging-related MASLD.VDR could serve as a potential molecular target for aging-related MASLD.展开更多
BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diag...BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.展开更多
Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pinea...Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.展开更多
Lifestyle and demographics of the world's population are causing serious health problems impacting the brain,increasing the incidence of Alzheimer's disease(AD)and other types of dementia.Although we have gain...Lifestyle and demographics of the world's population are causing serious health problems impacting the brain,increasing the incidence of Alzheimer's disease(AD)and other types of dementia.Although we have gained important insights into the pathogenic mechanisms of AD,only palliative care is available to patients.AD is characterized by the abnormal deposition of protein aggregates in the brain formed by amyloidβand hyper-phosphorylated,Tau in addition to neuroinflammation.展开更多
Diabetic foot attack(DFA)is the most severe presentation of diabetic foot disease,with the patient commonly displaying severe sepsis,which can be limb or life threatening.DFA can be classified into two main categories...Diabetic foot attack(DFA)is the most severe presentation of diabetic foot disease,with the patient commonly displaying severe sepsis,which can be limb or life threatening.DFA can be classified into two main categories:Typical and atypical.A typical DFA is secondary to a severe infection in the foot,often initiated by minor breaches in skin integrity that allow pathogens to enter and proliferate.This form often progresses rapidly due to the underlying diabetic pathophysiology of neuropathy,microvascular disease,and hyperglycemia,which facilitate infection spread and tissue necrosis.This form of DFA can present as one of a number of severe infective pathologies including pyomyositis,necrotizing fasciitis,and myonecrosis,all of which can lead to systemic sepsis and multiorgan failure.An atypical DFA,however,is not primarily infection-driven.It can occur secondary to either ischemia or Charcot arthropathy.Management of the typical DFA involves prompt diagnosis,aggressive infection control,and a multidisciplinary approach.Treatment can be guided by the current International Working Group on the Diabetic Foot/Infectious Diseases Society of America guidelines on diabetic foot infections,and the combined British Orthopaedic Foot and Ankle Society-Vascular Society guidelines.This article highlights the importance of early recognition,comprehensive management strategies,and the need for further research to establish standardized protocols and improve clinical outcomes for patients with DFA.展开更多
Aging is a process characterized by accumulating degenerative damages,resulting in the death of an organism ultimately.The main goal of aging research is to develop therapies that delay age-related diseases in human.S...Aging is a process characterized by accumulating degenerative damages,resulting in the death of an organism ultimately.The main goal of aging research is to develop therapies that delay age-related diseases in human.Since signaling pathways in aging of Caenorhabditis elegans(C.elegans),fruit flies and mice are evolutionarily conserved,compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human.Natural products have special resource advantage and with few side effect.Recently,many compounds or extracts from natural products slowing aging and extending lifespan have been reported.Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C.elegans or other species,and the prospect in developing antiaging medicine from natural products.展开更多
During normal aging,there is a decline in all physiological functions in the organism.One of the most affected organs is the brain,where neurons lose their proper synaptic function leading to cognitive impairment.Agin...During normal aging,there is a decline in all physiological functions in the organism.One of the most affected organs is the brain,where neurons lose their proper synaptic function leading to cognitive impairment.Aging is one of the main risk factors for the development of neurodegenerative diseases,such as Alzheimer’s disease.One of the main responsible factors for synaptic dysfunction in aging and neurodegenerative diseases is the accumulation of abnormal proteins forming aggregates.The most studied brain aggregates are the senile plaques,formed by Aβpeptide;however,the aggregates formed by phosphorylated tau protein have gained relevance in the last years by their toxicity.It is reported that neurons undergo severe mitochondrial dysfunction with age,with a decrease in adenosine 5′-triphosphate production,loss of the mitochondrial membrane potential,redox imbalance,impaired mitophagy,and loss of calcium buffer capacity.Interestingly,abnormal tau protein interacts with several mitochondrial proteins,suggesting that it could induce mitochondrial dysfunction.Nevertheless,whether tau-mediated mitochondrial dysfunction occurs indirectly or directly is still unknown.A recent study of our laboratory shows that phosphorylated tau at Ser396/404(known as PHF-1),an epitope commonly related to pathology,accumulates inside mitochondria during normal aging.This accumulation occurs preferentially in synaptic mitochondria,which suggests that it may contribute to the synaptic failure and cognitive impairment seen in aged individuals.Here,we review the main tau modifications promoting mitochondrial dysfunction,and the possible mechanism involved.Also,we discuss the evidence that supports the possibility that phosphorylated tau accumulation in synaptic mitochondria promotes synaptic and cognitive impairment in aging.Finally,we show evidence and argue about the presence of phosphorylated tau PHF-1 inside mitochondria in Alzheimer’s disease,which could be considered as an early event in the neurodegenerative process.Thus,phosphorylated tau PHF-1 inside the mitochondria could be considered such a potential therapeutic target to prevent or attenuate age-related cognitive impairment.展开更多
In the aging brain, cognitive function gradually dedines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel ne...In the aging brain, cognitive function gradually dedines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel neurological and psychiatric tool used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency transcranial magnetic stimulation （〈1 Hz） ameliorates synaptic plasticity and spatial cognitive deficits in learning-impaired mice. However, the mechanisms by which this treatment improves these deficits during normal aging are still unknown. Therefore, the current study investigated the effects of transcranial magnetic stimulation on the brain-derived neurotrophic factor signal pathway, synaptic protein markers, and spatial memory behavior in the hippocampus of normal aged mice. The study also investigated the downstream regulator, Fyn kinase, and the downstream effectors, synaptophysin and growth-associated protein 43 （both synaptic markers）, to determine the possible mechanisms by which transcranial magnetic stimulation regulates cognitive capacity. Transcranial magnetic stimulation with low intensity （110% average resting motor threshold intensity, 1 Hz） increased mRNA and protein levels of brain-derived neurotrophic factor, tropomyosin receptor kinase B, and Fyn in the hippocampus of aged mice. The treatment also upregulated the mRNA and protein expression of synaptophysin and growth-associated protein 43 in the hippocampus of these mice. In conclusion, brain-derived neurotrophic factor signaling may play an important role in sustaining and regulating structural synaptic plasticity induced by transcranial magnetic stimulation in the hippocampus of aging mice, and Fyn may be critical during this regulation. These responses may change the structural plasticity of the aging hippocampus, thereby improving cognitive function.展开更多
Red emissive carbon dots(CDs)are highly desired for biological applications.However,serious luminescence quenching of red emissive CDs in aqueous solution greatly hinders their application in high performance biologic...Red emissive carbon dots(CDs)are highly desired for biological applications.However,serious luminescence quenching of red emissive CDs in aqueous solution greatly hinders their application in high performance biological imaging.Herein,we reported a facile strategy to realize enhanced red emission of CDs in aqueous solution by surface modification with polyetherimide(PEI)via microwave heating method.High photoluminescence quantum yield(PLQY)of 25%was realized from the PEI functionalized CDs(CDs@PEI)in aqueous solution.The proposed PEI functionalization strategy not only protects the red emission against water molecules quenching,but also reverses the surface charges from negativity to positivity to promote cellular uptake of CDs,leading to clear cell imaging in red fluorescence region.More important,CDs@PEI exhibits much better photostability than commercial red emissive dye(MitoT racker red)in cell fluorescent imaging.Potential application of CDs@PEI on fast staining of cells for clonogenic assay has also been demonstrated.展开更多
BACKGROUND:Traumatic aortic dissection(TAD)has a low incidence but extremely high mortality.It always presents atypical clinical manifestations that are easily missed or misdiagnosed.This study mainly aims to describe...BACKGROUND:Traumatic aortic dissection(TAD)has a low incidence but extremely high mortality.It always presents atypical clinical manifestations that are easily missed or misdiagnosed.This study mainly aims to describe the imaging characteristics and management of TAD patients.METHODS:A retrospective analysis of 27 blunt TAD patients was performed between 2013 and 2020.Demographic features,imaging characteristics,and management were analyzed.RESULTS:Twenty-seven patients with type B aortic dissection(age 56.04±16.07 years,20 men)were included.Aortic intimal tears were mostly initiated from the aortic isthmus.The sizes of the proximal intimal tears in the greater curvature were larger than those in the lesser curvature(1.78±0.56 cm vs.1.24±0.52 cm,P=0.031).Compared with those in the control group,the maximum diameters of the aortic arch,thoracic aorta,and abdominal aorta in the TAD patients were all significantly widened(all P<0.050).Multivariate logistic regression analysis showed that the maximum diameter of the thoracic aorta was an independent risk factor for TAD,with a predictive value with an area under the receiver operating characteristic curve(AUC)of 0.673.Finally,26 patients successfully underwent delayed thoracic endovascular aortic repair(TEVAR),and the remaining one patient was treated conservatively.No progression of aortic dissection or death occurred during the six-month follow-up period.CONCLUSIONS:In blunt trauma,the aortic isthmus is the most common site of proximal intimal tears.An accurate diagnosis of TAD requires an overall consideration of medical history and imaging characteristics.Delayed TEVAR might be an eff ective therapeutic option for TAD.展开更多
In line with the worldwide trend in population aging,China has stepped into an aging society since 2000.The outstanding features of aging,including a large proportion of the older population,rapid growth,dramatic expa...In line with the worldwide trend in population aging,China has stepped into an aging society since 2000.The outstanding features of aging,including a large proportion of the older population,rapid growth,dramatic expansion of the oldest-old,and uneven aging distribution,have put China in a unique position.Besides,older population is expanding in parallel with the escalating burden of disease,high prevalence of disability,and low social involvement.However,China is not prepared to solve these problems in terms of the economy,awareness,geriatric care system,geriatric team,social security,or age-friendly environment.From the perspective of public health,we summarized the major challenges and proposed the following policy recommendations:(1)strengthening the top-level design and building a"government-leading,multi-sectoral-cooperating,and society-participating"pattern;(2)enhancing health services by implementing the"comprehensive health"strategy;(3)developing home and community care,coordinately enhance institutional care,promote integration of medical and care systems,and establish a multidimensional tailored care system;(4)optimizing geriatric the supporting system,included the construction of geriatric team and the long-term care insurance system;and(5)establishing a physical and socially age-friendly environment.展开更多
BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions ...BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.展开更多
Fluorescence lifetime is not only associated with the molecular structure f fuorophores,but alsostrongly depends on the environment around them,which llows fuorescence lifetime imagingmicroscopy(FLIM)to be used as a t...Fluorescence lifetime is not only associated with the molecular structure f fuorophores,but alsostrongly depends on the environment around them,which llows fuorescence lifetime imagingmicroscopy(FLIM)to be used as a tool for precise measurement of the cell or tisue microenvironment,This review introduces the basic principle of fuorescence lifetime imagingtechnology and its application in clinical medicine,including research and diagnosis of diseases inskin,brain,eyes,mouth,bone,blood vessels and cavity organs,and drug evaluation.As anoninvasive,nontoxic and nonionizing radiation technique,FLIM demonstrates excellent per-formance with high sensitivity and specificity,which allows to determine precise position of thelesion and,thus,has good potential for application in biomedical research and clinical diagnosis.展开更多
BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,diges...BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,digestion,and immunity,holds a pivotal role in the aging process of organisms.Although extensive research on liver aging has been carried out,no bibliometric analysis has been conducted to evaluate the scientific progress in this area.AIM To analyze basic knowledge,development trends,and current research frontiers in the field via bibliometric methods.METHODS We conducted bibliometric analyses via a range of analytical tools including Python,the bibliometrix package in R,CiteSpace,and VOSviewer.We retrieved publication data on liver aging research from the Web of Science Core Collection Database.A scientific knowledge map was constructed to display the contributions from different authors,journals,countries,institutions,as well as patterns of co-occurrence keywords and co-cited references.Additionally,gene regulation pathways associated with liver aging were analyzed via the STRING database.RESULTS We identified 4288 articles on liver aging,authored by 24034 contributors from 4092 institutions across 85 countries.Notably,the years 1991 and 2020 presented significant bursts in publication output.The United States led in terms of publications(n=1008,25.1%),citations(n=55205),and international collaborations(multiple country publications=214).Keywords such as“lipid metabolism”,“fatty liver disease”,“inflammation”,“liver fibrosis”and“target”were prominent,highlighting the current research hotspots.Notably,the top 64 genes,each of which appeared in at least 8 articles,were involved in pathways essential for cell survival and aging,including the phosphatidylinositol 3-kinase/protein kinase B,Forkhead box O and p53 signaling pathways.CONCLUSION This study highlights key areas of liver aging and offers a comprehensive overview of research trends,as well as insights into potential value for collaborative pursuits and clinical implementations.展开更多
1 Aging in Asia-an avalanche starts to form With decreasing fertilityrate and increasing life expectan-cy, the world is aging- withhighest rates in Asia. The socio-economic, financial and medicalconsequences of the ag...1 Aging in Asia-an avalanche starts to form With decreasing fertilityrate and increasing life expectan-cy, the world is aging- withhighest rates in Asia. The socio-economic, financial and medicalconsequences of the aging popu-展开更多
The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it ...The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.展开更多
基金supported by the National Institute on Aging(Nos.AG000723 and AG000578)(to VAB)the Fondation Sante(No.19656),Greece 2.0+1 种基金the National Recovery and Resilience Plan’s flagship program TAEDR-0535850the European Research Council(No.101077374-Synapto Mitophagy)(to KP)。
文摘N umerous neurological disorders negatively impact the nervous system,either through loss of neurons or by disrupting the normal functioning of neural networks.These impairments manifest as cognitive defects,memory loss,behavioral abnormalities,and motor dysfunctions.Decades of research have significantly advanced our understanding of the pathophysiology underlying neurodegene rative diseases,including Alzheimer's disease(AD),Parkinson's disease,amyotrophic lateral sclerosis,and others.
文摘In this editorial,a commentary on the article by Chang et al has been provided,the course of treatment of anorectal fistulas,especially complex and recurring ones,require accurate diagnostic procedures for determining ideal surgical procedures.Conventional ways of imaging sometimes fall short,offering insufficient insights in aggravated instances.In this editorial,a novel application of hydrogen peroxide-enhanced magnetic resonance imaging(HP-MRI)that promises significant improvements in the imaging of anorectal fistula.Study is based on a retrospective investigation of 60 patients,contrasts the new HP-MRI with conventional diagnostic techniques such as physical examination,trans-perineal ultrasonography and poor spatial resolution MRI.The findings demonstrate HP-MRI's incredible diagnostic performance,with sensitivity and specificity rates of 96.08%and 90.91%,respectively,and unparalleled interobserver agreement(Kappa values ranging from 0.80 to 0.89).It has been a significant advancement for assessment of anorectal fistulas providing a better roadmap for surgical planning,lowering recurrence rates as well as reduced personal and financial burden on patients by reducing the need for repeated treatment and extended hospital stays.The remaining funds can be utilized for treatment of other medical need.Ultimately HP-MRI provides us a healthier&more efficient society by improvising patients well-being&optimized healthcare infrastructure.
基金supported by the Research Project of the Shanghai Health Commission,No.2020YJZX0111(to CZ)the National Natural Science Foundation of China,Nos.82021002(to CZ),82272039(to CZ),82171252(to FL)+1 种基金a grant from the National Health Commission of People’s Republic of China(PRC),No.Pro20211231084249000238(to JW)Medical Innovation Research Project of Shanghai Science and Technology Commission,No.21Y11903300(to JG).
文摘Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders.
基金supported by the National Natural Science Foundation of China,No.81921006(to GHL)。
文摘The oral cavity is a complex physiological community encompassing a wide range of microorganisms.Dysbiosis of oral microbiota can lead to various oral infectious diseases,such as periodontitis and tooth decay,and even affect systemic health,including brain aging and neurodegenerative diseases.Recent studies have highlighted how oral microbes might be involved in brain aging and neurodegeneration,indicating potential avenues for intervention strategies.In this review,we summarize clinical evidence demonstrating a link between oral microbes/oral infectious diseases and brain aging/neurodegenerative diseases,and dissect potential mechanisms by which oral microbes contribute to brain aging and neurodegeneration.We also highlight advances in therapeutic development grounded in the realm of oral microbes,with the goal of advancing brain health and promoting healthy aging.
基金Supported by the National Natural Science Foundation of China,No.820300089.
文摘BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD)is defined by the abnormal lipid deposition in hepatocytes.The prevalence of MASLD is significantly increased in the elderly population,suggesting that aging may be related to the occurrence of MASLD.Emerging evidences suggest that vitamin D receptor(VDR)may be implicated in the progression of MASLD.Therefore,additional researches are warranted to elucidate whether VDR plays a role in aging-related MASLD.AIM To investigate the relationship between aging and MASLD and explore the role and related mechanisms of VDR in aging-related MASLD.METHODS Cellular senescence models were established,and the senescence phenotype of telomerase RNA component knockout mice was validated.These mice were then used as a senescence model for subsequent studies.Changes in VDR expression in the livers of aging mice were examined.VDR knockdown models,including cell knockdown models and hepatic-specific VDR knockout mice,were constructed,and MASLD was established in these models.Additionally,vitamin D(VD)-supplemented models,including senescent liver cell lines and senescent mice,were constructed.RESULTS The steatosis in senescent liver cells was more severe than in normal cells(P<0.05).Moreover,hepatic steatosis was significantly more pronounced in senescence model mice compared to control group when the MASLD model was successfully induced(P<0.05).Therefore,we concluded that aging aggravated hepatic steatosis.The hepatic expression of VDR increased after aging.VDR knockdown in senescent liver cells and senescent mice alleviated hepatic steatosis(P<0.05).When senescent liver cells were stimulated with VD,cellular steatosis was aggravated(P<0.05).However,VD supplementation had no effect on aging mice.CONCLUSION Aging can lead to increased hepatic steatosis,and the hepatic-specific knockdown of VDR alleviated aging-related MASLD.VDR could serve as a potential molecular target for aging-related MASLD.
基金Supported by the National Natural Science Foundation of China,No.82202185and Shanghai Science and Technology Development Foundation,No.22Y11911500.
文摘BACKGROUND Hepatic steatosis,characterized by fat accumulation in hepatocytes,can result from metabolic dysfunction-associated steatotic liver disease(MASLD),infections,alcoholism,chemotherapy,and toxins.MASLD is diagnosed via imaging or biopsy with metabolic criteria and may progress to metabolic dysfunction–asso-ciated steatohepatitis,potentially leading to fibrosis,cirrhosis,or cancer.The coexistence of hepatic steatosis with chronic hepatitis B(CHB)is mainly related to metabolic factors and increases mortality and cancer risks.As a noninvasive method,attenuation imaging(ATI)shows promise in quantifying liver fat,demonstrating strong correlation with liver biopsy.AIM To investigate the disparity of ATI for assessing biopsy-based hepatic steatosis in CHB patients and MASLD patients.METHODS The study enrolled 249 patients who underwent both ATI and liver biopsy,including 78 with CHB and 171 with MASLD.Hepatic steatosis was classified into grades S0 to S3 according to the proportion of fat cells present.Liver fibrosis was staged from 0 to 4 according to the meta-analysis of histological data in viral hepatitis scoring system.The diagnostic performance of attenuation coefficient(AC)values across different groups was compared for each grade of steatosis.Factors associated with the AC values were determined through linear regression analysis.A multivariate logistic regression model was established to predict≥S2 within the MASLD group.RESULTS In both the CHB and the MASLD groups,AC values increased significantly with higher steatosis grade(P<0.001).In the CHB group,the areas under the curve(AUCs)of AC for predicting steatosis grades≥S1,≥S2 and S3 were 0.918,0.960 and 0.987,respectively.In contrast,the MASLD group showed AUCs of 0.836,0.774,and 0.688 for the same steatosis grades.The diagnostic performance of AC for detecting≥S2 and S3 indicated significant differences between the two groups(both P<0.001).Multivariate linear regression analysis identified body mass index,trigly-cerides,and steatosis grade as significant factors for AC.When the steatosis grade is≥S2,it can progress to more serious liver conditions.A clinical model integrating blood biochemical parameters and AC was developed in the MASLD group to enhance the prediction of≥S2,achieving an AUC of 0.848.CONCLUSION The AC could effectively discriminate the degree of steatosis in both the CHB and MASLD groups.In the MASLD group,when combined with blood biochemical parameters,AC exhibited better predictive ability for moderate to severe steatosis.
基金supported by JSPS KAKENHI Grant Number JP22K11823 to AH and JP22J01508 to KW。
文摘Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.
基金funded by U.S.Air Force Office of Scientific Research FA9550-21-1-0096,FONDAP program 15150012,ANID/FONDEF ID1ID22I10120,FONDECY/ANID 1220573the US Army Medical Research Acquisition Activity(USAMRAA)project number AL2201415DoD Award HT9425-23-1-0990,AL220141(to CH)。
文摘Lifestyle and demographics of the world's population are causing serious health problems impacting the brain,increasing the incidence of Alzheimer's disease(AD)and other types of dementia.Although we have gained important insights into the pathogenic mechanisms of AD,only palliative care is available to patients.AD is characterized by the abnormal deposition of protein aggregates in the brain formed by amyloidβand hyper-phosphorylated,Tau in addition to neuroinflammation.
文摘Diabetic foot attack(DFA)is the most severe presentation of diabetic foot disease,with the patient commonly displaying severe sepsis,which can be limb or life threatening.DFA can be classified into two main categories:Typical and atypical.A typical DFA is secondary to a severe infection in the foot,often initiated by minor breaches in skin integrity that allow pathogens to enter and proliferate.This form often progresses rapidly due to the underlying diabetic pathophysiology of neuropathy,microvascular disease,and hyperglycemia,which facilitate infection spread and tissue necrosis.This form of DFA can present as one of a number of severe infective pathologies including pyomyositis,necrotizing fasciitis,and myonecrosis,all of which can lead to systemic sepsis and multiorgan failure.An atypical DFA,however,is not primarily infection-driven.It can occur secondary to either ischemia or Charcot arthropathy.Management of the typical DFA involves prompt diagnosis,aggressive infection control,and a multidisciplinary approach.Treatment can be guided by the current International Working Group on the Diabetic Foot/Infectious Diseases Society of America guidelines on diabetic foot infections,and the combined British Orthopaedic Foot and Ankle Society-Vascular Society guidelines.This article highlights the importance of early recognition,comprehensive management strategies,and the need for further research to establish standardized protocols and improve clinical outcomes for patients with DFA.
基金the Natural Science Foundation of China(81671405 and 81370453)Natural Science Foundation of Yunnan province(2013FA045 and 2015FB172)Open Funds of Guangdong Key Laboratory of Marine Materia Medica.
文摘Aging is a process characterized by accumulating degenerative damages,resulting in the death of an organism ultimately.The main goal of aging research is to develop therapies that delay age-related diseases in human.Since signaling pathways in aging of Caenorhabditis elegans(C.elegans),fruit flies and mice are evolutionarily conserved,compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human.Natural products have special resource advantage and with few side effect.Recently,many compounds or extracts from natural products slowing aging and extending lifespan have been reported.Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C.elegans or other species,and the prospect in developing antiaging medicine from natural products.
基金supported by FONDECYT,No.11170546,CONICYT PAI,No.77170091(to CTR)FONDECYT,No.3210591(to CJ).
文摘During normal aging,there is a decline in all physiological functions in the organism.One of the most affected organs is the brain,where neurons lose their proper synaptic function leading to cognitive impairment.Aging is one of the main risk factors for the development of neurodegenerative diseases,such as Alzheimer’s disease.One of the main responsible factors for synaptic dysfunction in aging and neurodegenerative diseases is the accumulation of abnormal proteins forming aggregates.The most studied brain aggregates are the senile plaques,formed by Aβpeptide;however,the aggregates formed by phosphorylated tau protein have gained relevance in the last years by their toxicity.It is reported that neurons undergo severe mitochondrial dysfunction with age,with a decrease in adenosine 5′-triphosphate production,loss of the mitochondrial membrane potential,redox imbalance,impaired mitophagy,and loss of calcium buffer capacity.Interestingly,abnormal tau protein interacts with several mitochondrial proteins,suggesting that it could induce mitochondrial dysfunction.Nevertheless,whether tau-mediated mitochondrial dysfunction occurs indirectly or directly is still unknown.A recent study of our laboratory shows that phosphorylated tau at Ser396/404(known as PHF-1),an epitope commonly related to pathology,accumulates inside mitochondria during normal aging.This accumulation occurs preferentially in synaptic mitochondria,which suggests that it may contribute to the synaptic failure and cognitive impairment seen in aged individuals.Here,we review the main tau modifications promoting mitochondrial dysfunction,and the possible mechanism involved.Also,we discuss the evidence that supports the possibility that phosphorylated tau accumulation in synaptic mitochondria promotes synaptic and cognitive impairment in aging.Finally,we show evidence and argue about the presence of phosphorylated tau PHF-1 inside mitochondria in Alzheimer’s disease,which could be considered as an early event in the neurodegenerative process.Thus,phosphorylated tau PHF-1 inside the mitochondria could be considered such a potential therapeutic target to prevent or attenuate age-related cognitive impairment.
基金supported by the Natural Science Foundation of Hebei Province of China,No.H2015206409Science and Technology Research Youth Fund Project of Hebei Colleges and Universities in China,No.QN20131068,QN2014140+1 种基金a grant from Health and Family Planning Commission Medical Scientific Research Project in Hebei Province of China,No.ZL20140017a grant from Hebei Science and Technology Support Program Project of China,No.132777209,132777135
文摘In the aging brain, cognitive function gradually dedines and causes a progressive reduction in the structural and functional plasticity of the hippocampus. Transcranial magnetic stimulation is an emerging and novel neurological and psychiatric tool used to investigate the neurobiology of cognitive function. Recent studies have demonstrated that low-frequency transcranial magnetic stimulation （〈1 Hz） ameliorates synaptic plasticity and spatial cognitive deficits in learning-impaired mice. However, the mechanisms by which this treatment improves these deficits during normal aging are still unknown. Therefore, the current study investigated the effects of transcranial magnetic stimulation on the brain-derived neurotrophic factor signal pathway, synaptic protein markers, and spatial memory behavior in the hippocampus of normal aged mice. The study also investigated the downstream regulator, Fyn kinase, and the downstream effectors, synaptophysin and growth-associated protein 43 （both synaptic markers）, to determine the possible mechanisms by which transcranial magnetic stimulation regulates cognitive capacity. Transcranial magnetic stimulation with low intensity （110% average resting motor threshold intensity, 1 Hz） increased mRNA and protein levels of brain-derived neurotrophic factor, tropomyosin receptor kinase B, and Fyn in the hippocampus of aged mice. The treatment also upregulated the mRNA and protein expression of synaptophysin and growth-associated protein 43 in the hippocampus of these mice. In conclusion, brain-derived neurotrophic factor signaling may play an important role in sustaining and regulating structural synaptic plasticity induced by transcranial magnetic stimulation in the hippocampus of aging mice, and Fyn may be critical during this regulation. These responses may change the structural plasticity of the aging hippocampus, thereby improving cognitive function.
基金supported by the National Natural Science Foundation of China(No.61922091)the Science and Technology Development Fund of Macao SAR(Nos.0040/2019/A1,0073/2019/AMJ,0128/2020/A3 and 0131/2020/A3)University of Macao(Nos.SRG2019-00163-IAPME,MYRG2019-00103-IAPME)。
文摘Red emissive carbon dots(CDs)are highly desired for biological applications.However,serious luminescence quenching of red emissive CDs in aqueous solution greatly hinders their application in high performance biological imaging.Herein,we reported a facile strategy to realize enhanced red emission of CDs in aqueous solution by surface modification with polyetherimide(PEI)via microwave heating method.High photoluminescence quantum yield(PLQY)of 25%was realized from the PEI functionalized CDs(CDs@PEI)in aqueous solution.The proposed PEI functionalization strategy not only protects the red emission against water molecules quenching,but also reverses the surface charges from negativity to positivity to promote cellular uptake of CDs,leading to clear cell imaging in red fluorescence region.More important,CDs@PEI exhibits much better photostability than commercial red emissive dye(MitoT racker red)in cell fluorescent imaging.Potential application of CDs@PEI on fast staining of cells for clonogenic assay has also been demonstrated.
基金This study was supported by the National Natural Science Foundation of China(81272075 and 81801572)the Foundation of Key Discipline Construction of Zhejiang Province for Traditional Chinese Medicine(2017-XK-A36).
文摘BACKGROUND:Traumatic aortic dissection(TAD)has a low incidence but extremely high mortality.It always presents atypical clinical manifestations that are easily missed or misdiagnosed.This study mainly aims to describe the imaging characteristics and management of TAD patients.METHODS:A retrospective analysis of 27 blunt TAD patients was performed between 2013 and 2020.Demographic features,imaging characteristics,and management were analyzed.RESULTS:Twenty-seven patients with type B aortic dissection(age 56.04±16.07 years,20 men)were included.Aortic intimal tears were mostly initiated from the aortic isthmus.The sizes of the proximal intimal tears in the greater curvature were larger than those in the lesser curvature(1.78±0.56 cm vs.1.24±0.52 cm,P=0.031).Compared with those in the control group,the maximum diameters of the aortic arch,thoracic aorta,and abdominal aorta in the TAD patients were all significantly widened(all P<0.050).Multivariate logistic regression analysis showed that the maximum diameter of the thoracic aorta was an independent risk factor for TAD,with a predictive value with an area under the receiver operating characteristic curve(AUC)of 0.673.Finally,26 patients successfully underwent delayed thoracic endovascular aortic repair(TEVAR),and the remaining one patient was treated conservatively.No progression of aortic dissection or death occurred during the six-month follow-up period.CONCLUSIONS:In blunt trauma,the aortic isthmus is the most common site of proximal intimal tears.An accurate diagnosis of TAD requires an overall consideration of medical history and imaging characteristics.Delayed TEVAR might be an eff ective therapeutic option for TAD.
基金the National Natural Science Foundation of China(Grant No.81941018).
文摘In line with the worldwide trend in population aging,China has stepped into an aging society since 2000.The outstanding features of aging,including a large proportion of the older population,rapid growth,dramatic expansion of the oldest-old,and uneven aging distribution,have put China in a unique position.Besides,older population is expanding in parallel with the escalating burden of disease,high prevalence of disability,and low social involvement.However,China is not prepared to solve these problems in terms of the economy,awareness,geriatric care system,geriatric team,social security,or age-friendly environment.From the perspective of public health,we summarized the major challenges and proposed the following policy recommendations:(1)strengthening the top-level design and building a"government-leading,multi-sectoral-cooperating,and society-participating"pattern;(2)enhancing health services by implementing the"comprehensive health"strategy;(3)developing home and community care,coordinately enhance institutional care,promote integration of medical and care systems,and establish a multidimensional tailored care system;(4)optimizing geriatric the supporting system,included the construction of geriatric team and the long-term care insurance system;and(5)establishing a physical and socially age-friendly environment.
基金supported by a grant from Bayer HealthCare/Bayer Schering Pharma AG
文摘BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.
基金funded by the Science and Technology Planning Fundamental Research Project of Shenzhen(No.JCYJ20150324140036853)National Natural Science Foundation of China(No.61378091)+1 种基金Ningbo Natural Science Foundation Project(No.2016A610032)the Central University Basic Scientic Research Business Expenses Project(No.NSIY051405).
文摘Fluorescence lifetime is not only associated with the molecular structure f fuorophores,but alsostrongly depends on the environment around them,which llows fuorescence lifetime imagingmicroscopy(FLIM)to be used as a tool for precise measurement of the cell or tisue microenvironment,This review introduces the basic principle of fuorescence lifetime imagingtechnology and its application in clinical medicine,including research and diagnosis of diseases inskin,brain,eyes,mouth,bone,blood vessels and cavity organs,and drug evaluation.As anoninvasive,nontoxic and nonionizing radiation technique,FLIM demonstrates excellent per-formance with high sensitivity and specificity,which allows to determine precise position of thelesion and,thus,has good potential for application in biomedical research and clinical diagnosis.
基金Supported by the National Natural Science Foundation of China,No.82271587,No.82172600,No.81972270,No.91849108,and No.82200665the National Key R&D Program of China,No.2022YFC3401601+2 种基金the Zhejiang Provincial Natural Science Foundation of China,No.LY22H030009the Zhejiang Provincial Science and Technology Program of Traditional Chinese Medicine,No.2023ZL480the Medical and Health Research Project of Zhejiang Province,No.2023RC153.
文摘BACKGROUND With the increasing of the global aging population,healthy aging and prevention of age-related diseases have become increasingly important.The liver,a vital organ involved in metabolism,detoxification,digestion,and immunity,holds a pivotal role in the aging process of organisms.Although extensive research on liver aging has been carried out,no bibliometric analysis has been conducted to evaluate the scientific progress in this area.AIM To analyze basic knowledge,development trends,and current research frontiers in the field via bibliometric methods.METHODS We conducted bibliometric analyses via a range of analytical tools including Python,the bibliometrix package in R,CiteSpace,and VOSviewer.We retrieved publication data on liver aging research from the Web of Science Core Collection Database.A scientific knowledge map was constructed to display the contributions from different authors,journals,countries,institutions,as well as patterns of co-occurrence keywords and co-cited references.Additionally,gene regulation pathways associated with liver aging were analyzed via the STRING database.RESULTS We identified 4288 articles on liver aging,authored by 24034 contributors from 4092 institutions across 85 countries.Notably,the years 1991 and 2020 presented significant bursts in publication output.The United States led in terms of publications(n=1008,25.1%),citations(n=55205),and international collaborations(multiple country publications=214).Keywords such as“lipid metabolism”,“fatty liver disease”,“inflammation”,“liver fibrosis”and“target”were prominent,highlighting the current research hotspots.Notably,the top 64 genes,each of which appeared in at least 8 articles,were involved in pathways essential for cell survival and aging,including the phosphatidylinositol 3-kinase/protein kinase B,Forkhead box O and p53 signaling pathways.CONCLUSION This study highlights key areas of liver aging and offers a comprehensive overview of research trends,as well as insights into potential value for collaborative pursuits and clinical implementations.
文摘1 Aging in Asia-an avalanche starts to form With decreasing fertilityrate and increasing life expectan-cy, the world is aging- withhighest rates in Asia. The socio-economic, financial and medicalconsequences of the aging popu-
基金Major Research Project of Shanghai City(No. 045211024)
文摘The degradation of crosslinked polyethylene (XLPE) cable insulation during service, such as thermo-oxidation and water treeing may lead to a premature electrical breakdown of the XLPE insulation cables. Therefore, it is necessary to optimize the period of replacement to evenly distribute the replacement cost by ascertaining the deterioration degree. Estimation of the aging degree is at present the most important task for diagnosis of the residual lifetime of the power cable insulation. This paper presents a study on the changes in the dielectric properties of the thermally aged XLPE cables in the frequency range from 0.07～10 MHz. Based on electrical and physicochemical characterization, some new "dactylograms" for the thermally aged XLPE cable insulation have been proposed.
