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Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism
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作者 Yujie Yang Xinyi Li +7 位作者 Jiaying Lu Jingjie Ge Mingjia Chen Ruixin Yao Mei Tian Jian Wang Fengtao Liu Chuantao Zuo 《Neural Regeneration Research》 SCIE CAS 2025年第1期93-106,共14页
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
关键词 aromatic amino acid decarboxylase brain imaging dopamine transporter Parkinson’s disease PARKINSONISM positron emission tomography presynaptic dopaminergic function vesicle monoamine transporter type 2
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Unraveling brain aging through the lens of oral microbiota
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作者 Qinchao Hu Si Wang +2 位作者 Weiqi Zhang Jing Qu Guang-Hui Liu 《Neural Regeneration Research》 SCIE CAS 2025年第7期1930-1943,共14页
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
关键词 Alzheimer's disease brain aging multiple sclerosis NEURODEGENERATION neurodegenerative diseases oral microbiota Parkinson's disease PERIODONTITIS BACTERIA Porphyromonas gingivalis
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The Applications of CRISPR Screening in Aging Research
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作者 XU Jia-Xin JING Yao-Bin +1 位作者 QU Jing LIU Guang-Hui 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2024年第9期1186-1196,共11页
The advancement of Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)gene editing technology has revolutionized the comprehension of human genome,propelling molecular and cellular biology research into ... The advancement of Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR)gene editing technology has revolutionized the comprehension of human genome,propelling molecular and cellular biology research into unexplored realms and accelerating progress in life sciences and medicine.CRISPR-based gene screening,recognized for its efficiency and practicality,is widely utilized across diverse biological fields.Aging is a multifaceted process governed by a myriad of genetic and epigenetic factors.Unraveling the genes regulating aging holds promise for understanding this intricate phenomenon and devising strategies for its assessment and intervention.This review provides a comprehensive overview of the progress in CRISPR screening and its applications in aging research,while also offering insights into future directions.CRISPR-based genetic-manipulation tools are positioned as indispensable instruments for mitigating aging and managing age-related diseases. 展开更多
关键词 Clustered Regularly Interspaced Short Palindromic Repeats(CRISPR) genetic screening AGING
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Preventing brain aging by the artificial enforcement of the unfolded protein response:future directions
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作者 Felipe Cabral-Miranda Claudio Hetz 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期393-394,共2页
As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly depe... As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families. 展开更多
关键词 DISEASES AGING DIRECTIONS
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Aging-induced memory loss due to decreased N1-acetyl-5-methoxykynuramine,a melatonin metabolite,in the hippocampus:a potential prophylactic agent for dementia
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作者 Kazuki Watanabe Atsuhiko Hattori 《Neural Regeneration Research》 SCIE CAS 2025年第6期1705-1706,共2页
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
关键词 metabolism primarily AGENT
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Aging impairs the osteocytic regulation of collagen integrity and bone quality
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作者 Charles A.Schurman Serra Kaya +12 位作者 Neha Dole Nadja M.Maldonado Luna Natalia Castillo Ryan Potter Jacob P.Rose Joanna Bons Christina D.King Jordan B.Burton Birgit Schilling Simon Melov Simon Tang Eric Schaible Tamara Alliston 《Bone Research》 SCIE CAS CSCD 2024年第1期78-94,共17页
Poor bone quality is a major factor in skeletal fragility in elderly individuals.The molecular mechanisms that establish and maintain bone quality,independent of bone mass,are unknown but are thought to be primarily d... Poor bone quality is a major factor in skeletal fragility in elderly individuals.The molecular mechanisms that establish and maintain bone quality,independent of bone mass,are unknown but are thought to be primarily determined by osteocytes.We hypothesize that the age-related decline in bone quality results from the suppression of osteocyte perilacunar/canalicular remodeling(PLR),which maintains bone material properties.We examined bones from young and aged mice with osteocyte-intrinsic repression of TGFβsignaling(TβRII^(ocy−/−))that suppresses PLR.The control aged bone displayed decreased TGFβsignaling and PLR,but aging did not worsen the existing PLR suppression in male TβRII^(ocy−/−)bone.This relationship impacted the behavior of collagen material at the nanoscale and tissue scale in macromechanical tests.The effects of age on bone mass,density,and mineral material behavior were independent of osteocytic TGFβ.We determined that the decline in bone quality with age arises from the loss of osteocyte function and the loss of TGFβ-dependent maintenance of collagen integrity. 展开更多
关键词 MAINTAIN primarily INTEGRITY
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Quality of life and aging
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作者 Masoud Gharib Vahid Rashedi 《Life Research》 2024年第3期1-1,共1页
The aging population has far-reaching implications for health,significantly influencing medical care and health policy.According to the World Health Organization(WHO),by 2030,one in six people worldwide will be aged 6... The aging population has far-reaching implications for health,significantly influencing medical care and health policy.According to the World Health Organization(WHO),by 2030,one in six people worldwide will be aged 60 years or older.Furthermore,the population of individuals aged 60 and older is projected to increase from 1 billion in 2020 to 1.4 billion in 2030.By 2050,this population is expected to double,reaching 2.1 billion.Similarly,the number of people aged 80 years and older is anticipated to triple between 2020 and 2050,reaching 426 million[1].This demographic shift toward older adults,known as population aging,initially began in high-income countries but has now extended to low and middle-income nations.By 2050,approximately two-thirds of the world’s population aged 60 and older will reside in these countries.The effects of this aging population pose significant challenges for human health,necessitating substantial societal adjustments[2]. 展开更多
关键词 DEMOGRAPHIC INCOME REACHING
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Current Perspective in the Discovery of Anti-aging Agents from Natural Products 被引量:10
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作者 Ai-Jun Ding Shan-Qing Zheng +5 位作者 Xiao-Bing Huang Ti-Kun Xing Gui-Sheng Wu Hua-Ying Sun Shu-Hua Qi Huai-Rong Luo 《Natural Products and Bioprospecting》 CAS 2017年第5期335-404,共70页
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
关键词 AGING Natural products ANTI-AGING Drug screening
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Low-frequency transcranial magnetic stimulation is beneficial for enhancing synaptic plasticity in the aging brain 被引量:3
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作者 Zhan-chi Zhang Feng Luan +3 位作者 Chun-yan Xie Dan-dan Geng Yan-yong Wang Jun Ma 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第6期916-924,共9页
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
关键词 neural regeneration non-invasive brain stimulation transcranial magnetic stimulation neurotrophic factor brain-derived neurotrophic factor NEUROPLASTICITY HIPPOCAMPUS AGING cognitive function
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Phosphorylated tau as a toxic agent in synaptic mitochondria: implications in aging and Alzheimer’s disease 被引量:2
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作者 Angie K.Torres Bastián I.Rivera +2 位作者 Catalina M.Polanco Claudia Jara Cheril Tapia-Rojas 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第8期1645-1651,共7页
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
关键词 age pathology AGING Alzheimer’s disease hippocampus memory MITOCHONDRIA PHF-1 phosphorylated tau synaptic mitochondria tau
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Analysis of imaging characteristics of blunt traumatic aortic dissection: an 8-year experience 被引量:1
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作者 Li Li Li-ying Lin Yuan-qiang Lu 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2022年第5期361-366,共6页
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
关键词 Blunt trauma Traumatic aortic dissection Imaging characteristic DIAGNOSIS Delayed thoracic endovascular aortic repair
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Aging in China: perspectives on public health 被引量:8
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作者 Yuting Han Yao He +3 位作者 Jun Lyu Canqing Yu Mingze Bian Liming Lee 《Global Health Journal》 2020年第1期11-17,共7页
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
关键词 AGING China ELDERLY PUBLIC HEALTH HEALTH status GERIATRIC care CHALLENGE Policy
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Gd-EOB-DTPA-enhanced magnetic resonance imaging for focal liver lesions in Chinese patients:a multicenter,open-label,phase Ⅲ study 被引量:39
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作者 Meng-Su Zeng Hui-Yi Ye +8 位作者 Liang Guo Wei-Jun Peng Jian-Ping Lu Gao-Jun Teng Josy Breuer Yi Huan Ping Li Jian-Rong Xu Chang-Hong Liang 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2013年第6期607-616,共10页
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
关键词 gadoxetate disodium magnetic resonance imaging LIVER focal liver lesions
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Applications,of fluorescence lifetime imaging in clinical medicine 被引量:2
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作者 Zhanwen Wang Yanping Zheng +7 位作者 Deqiang Zhao Ziwei Zhao Lixin Liu Artem Pliss Feiqi Zhu Jun Liu Junle Qu Ping Luan 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2018年第1期106-122,共17页
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
关键词 Fluorescence lifetime fluorescence lifetime imaging microscopy clinical medicine
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First Asian ISSAM Meeting on the Aging Male, Kuala Lumpur,Malaysia, 1-3 March 2001-an overview
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作者 RenateLeinmüller BrunoLunenfeld 《Asian Journal of Andrology》 SCIE CAS CSCD 2001年第2期151-154,共4页
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
关键词 Kuala Lumpur Malaysia March 2001-an overview First Asian ISSAM Meeting on the Aging Male
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Studies on the Effect of Accelerated Thermal Aging on Electrical and Physicochemical Properties of XLPE Cable
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作者 金天雄 金之俭 +3 位作者 江平开 朱子述 刘飞 金义天 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第1期91-95,共5页
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
关键词 electrical and physicochemical properties accelerated thermal aging crosslinked polyethylene (XLPE) cable insulation
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In situ Raman imaging of high-temperature solid-state reactions in the CaSO4-SiO2 system
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作者 Nadine Bohme Kerstin Hauke +1 位作者 Manuela Neuroth Thorsten Geisler 《International Journal of Coal Science & Technology》 EI 2019年第2期247-259,共13页
The deposition of mineral phases on the heat transfer surfaces of brown coal power plants may have a negative effect on power plant boilers. The paragenesis of these deposits contains information about the actual temp... The deposition of mineral phases on the heat transfer surfaces of brown coal power plants may have a negative effect on power plant boilers. The paragenesis of these deposits contains information about the actual temperature prevailed during the combustion of lignite, if the temperature-dependences of distinct mineral transformations or reactions are known. Here, we report results of a sintering study (to ?1100℃) with samples containing anhydrite, quartz, and gehlenite, which are typical components of Rhenish lignite ashes. Thermal decompositions and solid-state reactions were analyzed (1) in situ and (2) both in situ and after quenching using confocal hyperspectral Raman imaging. This novel application of confocal Raman spectroscopy provides temperature-and time-resolved, 2-dimensional information about sintering processes with a micrometer-scale resolution. In the course of the sintering experiments with anhydrite and quartz with a weight ratio of 2:1 both polymorphs wollastonite and pseudowollastonite were identified in situ at about 920 and 1000℃, respectively. The formation of pseudowollastonite was thus observed about 120℃ below the phase transition temperature, demonstrating that it can form metastably. In addition,α′L-Ca2SiO4 was identified at about 1100℃. In samples containing equal weight fractions of anhydrite and quartz that were quenched after firing for 9h at about 1100℃,β-Ca2SiO4 (larnite) crystallized as rims around anhydrite grains and in direct contact to wollastonite. We furthermore observed that, depending on the ratio between quartz and anhydrite, wollastonite replaced quartz grains between 920 and 1100℃., i.e., the higher the quartz content, the lower the formation temperature of wollastonite. 展开更多
关键词 ASH deposition CALCIUM SILICATE CALCIUM SULFATE High-temperature RAMAN imaging
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Standardization of choroidal thickness measurements using enhanced depth imaging optical coherence tomography
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作者 Nattapon Boonarpha Yalin Zheng +5 位作者 Alexandros N.Stangos Huiqi Lu Ankur Raj Gabriela Czanner Simon P.Harding Jayashree Nair-Sahni 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第3期484-491,共8页
AIM: To describe and evaluate a standardized protocol for measuring the choroidal thickness(Ch T) using enhanced depth imaging optical coherence tomography(EDI OCT).METHODS: Single 9 mm EDI OCT line scans across the f... AIM: To describe and evaluate a standardized protocol for measuring the choroidal thickness(Ch T) using enhanced depth imaging optical coherence tomography(EDI OCT).METHODS: Single 9 mm EDI OCT line scans across the fovea were used for this study. The protocol used in this study classified the EDI OCT images into four groups based on the appearance of the choroidal-scleral interface and suprachoroidal space. Two evaluation iterations of experiments were performed: first, the protocol was validated in a pilot study of 12 healthy eyes. Afterwards, the applicability of the protocol was tested in 82 eyes of patients with diabetes. Inter-observer and intra-observer agreements on image classifications were performed using Cohen’s kappa coefficient(κ). Intraclass correlation coefficient(ICC) and Bland-Altman’s methodology were used for the measurement of the Ch T.RESULTS: There was a moderate(κ=0.42) and perfect(κ =1) inter- and intra-observer agreements on image classifications from healthy eyes images and substantial(κ =0.66) and almost perfect(κ =0.86) agreements from diabetic eyes images. The proposed protocol showed excellent inter- and intra-observer agreements for the Ch T measurements on both, healthy eyes and diabetic eyes(ICC 】0.90 in all image categories). The Bland-Altman plot showed a relatively large Ch T measurement agreement in the scans that contained less visible choroidal outer boundary. CONCLUSION: A protocol to standardize Ch T measurements in EDI OCT images has been developed;the results obtained using this protocol show that the technique is accurate and reliable for routine clinical practice and research. 展开更多
关键词 CHOROID enhanced depth imaging choroidal thickness optical coherence tomography DIABETES
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Skin Anti-Aging Benefits of a 2% Resveratrol Emulsion
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作者 Anke Schulte to Brinke Ciska Janssens-Böcker Martina Kerscher 《Journal of Cosmetics, Dermatological Sciences and Applications》 2021年第2期155-168,共14页
<strong>Background:</strong> Young and intact skin is highly responsive. As skin ages, its responsiveness decreases. Production of structural components of the skin slows down and signs of skin aging appea... <strong>Background:</strong> Young and intact skin is highly responsive. As skin ages, its responsiveness decreases. Production of structural components of the skin slows down and signs of skin aging appear. External influences like UV radiation and pollution contribute to signs of skin aging. They lead to an increased formation of so-called free radicals. Bioactive antioxidant compounds, such as polyphenols, have beneficial effects on skin health by free radical scavenging. The purpose of this study was to evaluate the topical effects of new and highly concentrated resveratrol containing emulsion (Medskin Solutions Dr. Suwelack AG, 2% trans-resveratrol) on age-related alterations to the skin. <strong>Methods:</strong> A clinical observation study was performed on 20 subjects to observe the effects of a 2% resveratrol emulsion on typical signs of skin aging. Product was applied once daily for a period of 8 weeks in combination with a standardized treatment. Tested parameters were skin elasticity, skin barrier function, skin smoothness, skin thickness and density. <strong>Results:</strong> After 8 weeks of treatment, skin pH value is significantly lowered and skin barrier function improved. The value of skin elasticity (+5.3%), and skin density (+ 10.7%) had increased, while skin roughness (-6.4%) and skin dispensability (-45.9%) had diminished. Intensity of skin redness had decreased. Furthermore, expert and participant evaluations show satisfaction, especially with regard to skin smoothness and skin moisture. Conclusion: The resveratrol emulsion shows positive outcomes by supporting reduction of skin wrinkling and increasing skin firmness, as well as reducing skin redness, and is therefore an all-round anti-aging treatment. 展开更多
关键词 RESVERATROL EMULSION Skin Care Skin Aging
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Mechanisms of neuroplasticity and brain degeneration: strategies for protection during the aging process 被引量:9
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作者 Mariana Toricelli Arthur Antonio Ruiz Pereira +4 位作者 Guilherme Souza Abrao Helena Nascimento Malerba Julia Maia Hudson Sousa Buck Tania Araujo Viel 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第1期58-67,共10页
Aging is a dynamic and progressive process that begins at conception and continues until death.This process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the ind... Aging is a dynamic and progressive process that begins at conception and continues until death.This process leads to a decrease in homeostasis and morphological,biochemical and psychological changes,increasing the individual’s vulnerability to various diseases.The growth in the number of aging populations has increased the prevalence of chronic degenerative diseases,impairment of the central nervous system and dementias,such as Alzheimer’s disease,whose main risk factor is age,leading to an increase of the number of individuals who need daily support for life activities.Some theories about aging suggest it is caused by an increase of cellular senescence and reactive oxygen species,which leads to inflammation,oxidation,cell membrane damage and consequently neuronal death.Also,mitochondrial mutations,which are generated throughout the aging process,can lead to changes in energy production,deficiencies in electron transport and apoptosis induction that can result in decreased function.Additionally,increasing cellular senescence and the release of proinflammatory cytokines can cause irreversible damage to neuronal cells.Recent reports point to the importance of changing lifestyle by increasing physical exercise,improving nutrition and environmental enrichment to activate neuroprotective defense mechanisms.Therefore,this review aims to address the latest information about the different mechanisms related to neuroplasticity and neuronal death and to provide strategies that can improve neuroprotection and decrease the neurodegeneration caused by aging and environmental stressors. 展开更多
关键词 cell senescence cell signaling CHOLINERGIC enriched environment long-term potentiation NEURODEGENERATION NEUROGENESIS neuroinflammatory neuronal death NEUROPROTECTION neurotophin
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