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Insulin sensitizers for the treatment of non-alcoholic fatty liver disease 被引量:14
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作者 Zeynel Abidin Ozturk Abdurrahman Kadayifci 《World Journal of Hepatology》 CAS 2014年第4期199-206,共8页
Non-alcoholic fatty liver disease(NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome,which includes hypertension,central obesity,dyslipidemia and insuli... Non-alcoholic fatty liver disease(NAFLD) is the leading cause of liver disease in the Western world and is closely associated with metabolic syndrome,which includes hypertension,central obesity,dyslipidemia and insulin resistance.NAFLD includes a wide spectrum of liver alterations,ranging from simple hepatic steatosis to variable degrees of fibrosis,cirrhosis and even hepatocellular carcinoma.Although the etiology and progression of the disorder remain poorly understood,insulin resistance is considered to play a pivotal role in the pathogenesis.Insulin sensitizers such as biguanides,thiazolidinediones(TZDs),glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase 4 inhibitors have been studied as therapeutic approaches for NAFLD in recent years.Metformin improves insulin sensitivity and serum alanine transaminase and aspartate transaminase(ALT/AST) levels in the majority of subjects; however,it has no significant effect on liver histology.TZDs improve insulin sensitivity,serum ALT/ AST levels and histology in some cases,but there are some concerns about the safety of long-term therapy.Selection of appropriate patients for avoiding side effects and the treatment of underlying disease are themain points.These drugs are the best choice for the treatment of NAFLD in patients with type 2 DM who are also candidates for treatment with an insulin sensitizer.The present review provides an overview of insulin sensitizers in the treatment of NAFLD. 展开更多
关键词 Insulin sensitizers Metformin Non-alcoholic fatty liver disease Non-alcoholic STEATOHEPATITIS THIAZOLIDINEDIONES
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Design consideration of phthalocyanines as sensitizers for enhanced sono-photodynamic combinatorial therapy of cancer
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作者 Lindokuhle Cindy Nene Heidi Abrahamse 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2024年第3期1077-1097,共21页
Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development ... Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development of resistance for some,including chemotherapy,radiation,and surgery.Sono-photodynamic combinatorial therapy(SPDT)has been developed as an alternative treatment modality which offers a non-invasive and controllable therapeutic approach.SPDT combines the mechanism of action of sonodynamic therapy(SDT),which uses ultrasound,and photodynamic therapy(PDT),which uses light,to activate a sensitizer and initiate cancer eradication.The use of phthalocyanines(Pcs)as sensitizers for SPDT is gaining interest owing to their ability to induce intracellular oxidative stress and initiate toxicity under SDT and PDT.This review discusses some of the structural prerequisites of Pcs which may influence their overall SPDT activities in cancer therapy. 展开更多
关键词 Sonodynamic therapy Photodynamic therapy Combinatorial therapy Phthalocyanines SENSITIZER CANCER
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Antarctic red algae in dye-sensitized photoelectrochemical cells for water splitting
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作者 Florentina ARISPE María Fernanda CERDÁ 《Advances in Polar Science》 CSCD 2024年第2期219-227,共9页
Phycoerythrin extracted from Antarctic red seaweeds shows promising characteristics to be applied as an anode sensitizer in water-splitting photoelectrochemical cells.Under light irradiation and using an LED lamp,the ... Phycoerythrin extracted from Antarctic red seaweeds shows promising characteristics to be applied as an anode sensitizer in water-splitting photoelectrochemical cells.Under light irradiation and using an LED lamp,the red-colored protein shows an interesting ability to profit the incident light,as confirmed by the presence of oxygen bubbles next to the electrode surface without applying any external potential.Our results showed that the addition of iodide is helpful to allow the regeneration of the dye;nevertheless,oxygen evolution is not favored.Thermodynamics analysis of the involved semi-reactions is also helpful to understand the observed results.The exploration of Antarctic resources offers then an alternative for the development of green energies,with a particular focus on their use as sensitizers to profit from the sunlight in water-splitting as well as in photovoltaic devices. 展开更多
关键词 sensitizers WATER-SPLITTING red algae ELECTROCHEMICAL
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近红外无创血糖浓度的Label Sensitivity算法和支持向量机回归
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作者 孟琪 赵鹏 +4 位作者 宦克为 李野 姜志侠 张瀚文 周林华 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第3期617-624,共8页
近红外光谱分析技术在生物医学工程领域具有广阔应用前景。无创且持续性地测量能实时监控人体血糖水平,给糖尿病患者带来极大便利性、提高生存质量、降低糖尿病并发症发生率具有很大的社会效益。无创血糖监测的想法提出较早,但仍然存在... 近红外光谱分析技术在生物医学工程领域具有广阔应用前景。无创且持续性地测量能实时监控人体血糖水平,给糖尿病患者带来极大便利性、提高生存质量、降低糖尿病并发症发生率具有很大的社会效益。无创血糖监测的想法提出较早,但仍然存在预测精度低、预测值与标签值相关性不高等难点,至今没有达到临床要求。近年来,光谱检测技术发展迅猛且机器学习技术在智能信息处理方面具有明显优势,两者结合可以有效提高人体无创血糖医学监测模型的精度和普适性。提出了一种标签敏感度算法(LS),并结合支持向量机方法建立了人体血糖含量预测模型。使用近红外光谱仪采集了4名志愿者食指处动态血液光谱数据(每名志愿者28组数据),并使用多元散射矫正(MSC)方法消除了部分光散射的影响。考虑血糖对不同波长光的吸收有差异,提出了基于血糖浓度标签差的特征波长挑选方法,并构建了标签敏感度支持向量机(LSSVR)预测模型。设计实验,对比该模型与偏最小二乘回归(PLSR)和区分度支持向量机(FSSVR)算法。结果表明,LS算法的最佳特征波长数为32,经特征波长选择后的LSSVR表现最佳,其均方误差降低至0.02 mmol·L^(-1),明显优于全谱段PLSR模型,血糖浓度的预测值与标签值的相关系数提升至99.8%,预测值全部位于可容许误差的克拉克网格A区内。LSSVR模型的优异表现为早日实现血糖的无创监测提供了新思路。 展开更多
关键词 无创血糖 近红外光谱 特征波长 Label Sensitivity算法 支持向量机
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Identification, pathogenicity, and fungicide sensitivity of Eutiarosporella dactylidis associated with leaf blight on maize in China 被引量:1
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作者 Cheng Guo Xiaojie Zhang +9 位作者 Baobao Wang Zhihuan Yang Jiping Li Shengjun Xu Chunming Wang Zhijie Guo Tianwang Zhou Liu Hong Xiaoming Wang Canxing Duan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期888-900,共13页
Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and s... Maize(Zea mays L.) is an economically vital grain crop that is cultivated worldwide. In 2011, a maize foliar disease was detected in Lingtai and Lintao counties in Gansu Province, China. The characteristic signs and symptoms of this disease include irregular chlorotic lesions on the tips and edges of infected leaves and black punctate fruiting bodies in dead leaf tissues. Given favourable environmental conditions, this disease spread to areas surrounding Gansu. In this study, infected leaves were collected from Gansu and Ningxia Hui Autonomous Region between 2018and 2020 to identify the disease-causing pathogen. Based on morphological features, pathogenicity tests, and multilocus phylogenetic analysis involving internal transcribed spacer(ITS), 18S small subunit rDNA(SSU), 28S large subunit rDNA(LSU), translation elongation factor 1-alpha(TEF), and β-tubulin(TUB) sequences, Eutiarosporella dactylidis was identified as the causative pathogen of this newly discovered leaf blight. Furthermore, an in vitro bioassay was conducted on representative strains using six fungicides, and both fludioxonil and carbendazim were found to significantly inhibit the mycelial growth of E. dactylidis. The results of this study provide a reference for the detection and management of Eutiarosporella leaf blight. 展开更多
关键词 maize leaf blight MORPHOLOGY molecular phylogeny Eutiarosporella dactylidis fungicide sensitivity
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Recent progress in sono-photodynamic cancer therapy:From developed new sensitizers to nanotechnology-based efficacy-enhancing strategies 被引量:6
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作者 Yilin Zheng Jinxiang Ye +2 位作者 Ziying Li Haijun Chen Yu Gao 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2021年第8期2197-2219,共23页
Many sensitizers have not only photodynamic effects,but also sonodynamic effects.Therefore,the combination of sonodynamic therapy(SDT)and photodynamic therapy(PDT)using sensitizers for sonophotodynamic therapy(SPDT)pr... Many sensitizers have not only photodynamic effects,but also sonodynamic effects.Therefore,the combination of sonodynamic therapy(SDT)and photodynamic therapy(PDT)using sensitizers for sonophotodynamic therapy(SPDT)provides alternative opportunities for clinical cancer therapy.Although significant advances have been made in synthesizing new sensitizers for SPDT,few of them are successfully applied in clinical settings.The anti-tumor effects of the sensitizers are restricted by the lack of tumor-targeting specificity,incapability in deep intratumoral delivery,and the deteriorating tumor microenvironment.The application of nanotechnology-based drug delivery systems(NDDSs)can solve the above shortcomings,thereby improving the SPDT efficacy.This review summarizes various sensitizers as sono/photosensitizers that can be further used in SPDT,and describes different strategies for enhancing tumor treatment by NDDSs,such as overcoming biological barriers,improving tumor-targeted delivery and intratumoral delivery,providing stimuli-responsive controlled-release characteristics,stimulating anti-tumor immunity,increasing oxygen supply,employing different therapeutic modalities,and combining diagnosis and treatment.The challenges and prospects for further development of intelligent sensitizers and translational NDDSs for SPDT are also discussed. 展开更多
关键词 sensitizers Sonodynamic therapy Photodynamic therapy Sono-photodynamic therapy Nanoparticles Drug delivery Cancer Efficacy-enhancing strategies
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A mini-review on recent progress of new sensitizers for luminescence of lanthanide doped nanomaterials 被引量:7
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作者 Hongxin Zhang Zi-Han Chen +1 位作者 Xuan Liu Fan Zhang 《Nano Research》 SCIE EI CAS CSCD 2020年第7期1795-1809,共15页
Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great... Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great attractions,the light absorption of these lanthanide doped nanocrystals is inherently weak due to the electric dipole-forbidden 4f→4f transitions.Even worse,the quantum yields of upconverison nanocrystals are very low,which will unavoidably hinder their further applications.In a typical lanthanide luminescent nanosystem,both sensitizers as light absorption centers and activators as light emitting centers are necessary and important for desired luminescence properties.Among various sensitization systems,only Yb3+and Nd+are considered as the most efficient sensitizers.Thus,the corresponding excitation wavelengths are strictly limited around 980 and 808 nm.To enrich excitation wavelengths and boost luminescence intensity,exploring more sensitization units that possess larger absorption cross section,higher efficiency of energy transfer process and independent excitation is imperative and beneficial for the demands of different applications,such as broadened absorption in near infrared(NIR)region for higher conversion efficiency of solar cells,prolonged excitation wavelength to second near infrared windows region(NIR Ⅱ,1,000-1,700 nm)for in vivo fluorescence imaging with deeper tissue depth and higher spatial resolution,more orthogonal excitations and emissions to improve optical multiplexing,and so on.Therefore,in the review,we primarily conclude several major energy transfer mechanisms from sensitizers to activators.Then we present three kinds of sensitizers,including lanthanide ions,organic dyes and quantum dots(QDs),and introduce the newly designed sensitization system that allows us to exploit superior excitation wavelength and amplity luminescence intensity.Finally,several future challenges and opportunities for the sensitizing strategies are discussed in hope of directing and broadening the applications of lanthanide nanosystem. 展开更多
关键词 lanthanide luminescenee new sensitizers organic dyes quantum dots
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Molecular Design of D-Tr-A Type II Organic Sensitizers for Dye Sensitized Solar Cells 被引量:1
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作者 李士锋 杨希川 +3 位作者 瞿定峰 王维瀚 王瑜 孙立成 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2012年第10期2315-2321,共7页
Four new type II organic dyes with D-n-A structure (donor-n-conjugated-acceptor) and two typical type II sen- sitizers based on catechol as reference dyes are synthesized and applied in dye sensitized solar cells (... Four new type II organic dyes with D-n-A structure (donor-n-conjugated-acceptor) and two typical type II sen- sitizers based on catechol as reference dyes are synthesized and applied in dye sensitized solar cells (DSCs). The four dyes can be adsorbed on TiO2 through hydroxyl group directly. Electron injection can occur not only through the anchoring group (hydroxyl group) but also through the electron-withdrawing group (-CN) located close to the semiconductor surface. Experimental results show that the type II sensitizers with a D-π-A system obviously out- perform the typical type II sensitizers providing much higher conversion efficiency due to the strong electronic push-pull effect. Among these dyes, LS223 gives the best solar energy conversion efficiency of 3.6%, with Jsc = 7.3 mAocm 2, Voc=0.69 V, FF=0.71, the maximum IPCE value reaches 74.9%. 展开更多
关键词 type II sensitizers D-π-A photovoltaic devices solar cells
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Significantly enhanced thermal stability of HMX by phase-transition lysozyme coating
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作者 Jiahui Liu Congmei Lin +3 位作者 Jianhu Zhang Chengcheng Zeng Zhijian Yang Fude Nie 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期60-68,共9页
A new robust bio-inspired route by using lysozyme aqueous solution for surface modification on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)was described in this paper.HMX crystals were coated by in situ phase transitio... A new robust bio-inspired route by using lysozyme aqueous solution for surface modification on 1,3,5,7-tetranitro-1,3,5,7-tetrazocane(HMX)was described in this paper.HMX crystals were coated by in situ phase transition of lysozyme(PTL)molecules.The HMX decorated by PTL was characterized by SEM,XRD,FTIR and XPS,demonstrating a dense core-shell coating layer.The coverage of lysozyme on HMX crystal was calculated by the ratio of sulfur content.The surface coverage increased from 60.5% to 93.5% when the content of PTL was changed from 0.5 wt% to 2.0 wt%,indicating efficient coating.The thermal stability of HMX was investigated by in situ XRD and DSC.The thermal phase transition temperature of HMX(β to δ phase)was delayed by 42℃ with 2.0 wt% PTL coating,which prevented HMX from thermal damage and sensitivity by the effect of PTL coating.After heating at 215℃,large cracks appeared in the naked HMX crystal,while the PTL coated HMX still maintained intact,with the impact energy of HMX dropped dramatically from 5 J to 2 J.However,the impact energy of HMX with 1.0 wt% and 2.0 wt% coating content(HMX@PTL-1.0 and HMX@PTL-2.0)was unchanged(5 J).Present results potentially enable large-scale fabrication of polymorphic energetic materials with outstanding thermal stability by novel lysozyme coating. 展开更多
关键词 HMX LYSOZYME Phase transition Thermal stability Sensitivity
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Resistance development,cross-resistance,and fitness costs associated with Aphis gossypii resistance towards sulfoxaflor and acetamiprid in different geographical regions
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作者 Wei Wang Renfu Zhang +4 位作者 Haiyang Liu Ruifeng Ding Qiushi Huang Ju Yao Gemei Liang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第7期2332-2345,共14页
Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii population... Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii populations with different basal insecticide resistance levels,and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance,as well as differences in fitness.Under the same selection pressure,Yarkant A.gossypii(with low basal insecticide resistance)evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A.gossypii(with high basal insecticide resistance),and the evolution of A.gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe,Xingjiang,China.The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid,imidacloprid,thiamethoxam and pymetrozine;while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor,imidacloprid,thiamethoxam,pymetrozine,and chlorpyrifos.The relative fitness of A.gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.The relative fitness levels of the sulfoxaflor-resistant strains(Yarkant-SulR and Jinghe-SulR)were lower than those of the acetamipridresistant strains(Yarkant-AceR and Jinghe-AceR).In addition,the relative fitness levels of sulfoxaflor-and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.In summary,basal insecticide resistance of A.gossypii and insecticide type affected the evolution of resistance to insecticides in A.gossypii,as well as cross-resistance to other insecticides.The sulfoxaflor-and acetamiprid-resistant A.gossypii strains had obvious fitness costs.The results of this work will contribute to the insecticide resistance management and integrated management of A.gossypii. 展开更多
关键词 Aphis gossypii sulfoxaflor ACETAMIPRID CROSS-RESISTANCE fitness costs different sensitivities
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Sensitivity and resistance risk analysis of Didymella bryoniae populations to fluopyram
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作者 Zhiwen Wu Xiaowei Cai +2 位作者 Xuewei Mao Mingguo Zhou Yiping Hou 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第7期2306-2317,共12页
Fluopyram is an succinate dehydrogenase inhibitors(SDHI)fungicide that has been registered in China to control gummy stem blight(GSB)in watermelons for many years.However,whether the field pathogens of GSB are still s... Fluopyram is an succinate dehydrogenase inhibitors(SDHI)fungicide that has been registered in China to control gummy stem blight(GSB)in watermelons for many years.However,whether the field pathogens of GSB are still sensitive to fluopyram or not is unknown.Therefore,we collected 69 Didymella bryoniae isolates from the fields that usually use fluopyram to control GSB to determine the sensitivity change.The EC50(50%inhibition effect)values of fluopyram against D.bryoniae ranged from 0.0691 to 0.3503μg mL–1 and the variation factor was 5.07.The mean EC50 value was(0.1579±0.0669)μg mL–1 and the curve of sensitivity was unimodal.No resistant strains were found in the isolates,which means that the pathogens were still sensitive to fluopyram.The minimal inhibition concentration(MIC)of fluopyram against D.bryoniae was 3μg mL–1.Four low-resistant mutants and two mediumresistant mutants were obtained using fungicide taming and the resistance of mutants could be inherited stably.The growth rate of mutants decreased significantly compared with that of wild-type strains while the biomass of most mutants was similar to that of wild-type strains.The sensitivity of most resistant mutants to various stresses was increased compared with that of wild-type strains.The virulence of mutants receded except for low-resistant mutant XN51FR-1,which had the same lesion area as XN51 on the watermelon leaves.The results indicated that the fitness of resistant mutants was decreased compared with that of wild-type strains.The cross-resistance assay indicated that fluopyram-resistant mutants were positive cross-resistant to all six SDHI fungicides in this test but were still sensitive to fluazinam and tebuconazole.So the resistance risk of D.bryoniae to fluopyram was moderate.In addition,we found that the SdhB gene of low-resistant mutant XN30FR-1 had three new point mutations at positions K258N,A259P,and H277N.Medium-resistant mutant XN52FR-1 showed a mutation at position H277N and other mutants did not have any point mutation. 展开更多
关键词 fluopyram D.bryoniae sensitivity risk assessment
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Finite element model updating for structural damage detection using transmissibility data
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作者 Ahmad Izadi Akbar Esfandiari 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期87-101,共15页
This paper presents a new finite element model updating method for estimating structural parameters and detecting structural damage location and severity based on the structural responses(output-only data).The method ... This paper presents a new finite element model updating method for estimating structural parameters and detecting structural damage location and severity based on the structural responses(output-only data).The method uses the sensitivity relation of transmissibility data through a least-squares algorithm and appropriate normalization of the extracted equations.The proposed transmissibility-based sensitivity equation produces a more significant number of equations than the sensitivity equations based on the frequency response function(FRF),which can estimate the structural parameters with higher accuracy.The abilities of the proposed method are assessed by using numerical data of a two-story two-bay frame model and a plate structure model.In evaluating different damage cases,the number,location,and stiffness reduction of the damaged elements and the severity of the simulated damage have been accurately identified.The reliability and stability of the presented method against measurement and modeling errors are examined using error-contaminated data.The parameter estimation results prove the method’s capabilities as an accurate model updating algorithm. 展开更多
关键词 damage detection model updating output-only TRANSMISSIBILITY sensitivity equation
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Linear dichroism transition and polarization-sensitive photodetector of quasi-one-dimensional palladium bromide
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作者 朱万里 甄伟立 +5 位作者 牛瑞 焦珂珂 岳智来 胡慧杰 薛飞 张昌锦 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期532-539,共8页
Perpendicular optical reversal of the linear dichroism transition has promising applications in polarization-sensitive optoelectronic devices. We perform a systematical study on the in-plane optical anisotropy of quas... Perpendicular optical reversal of the linear dichroism transition has promising applications in polarization-sensitive optoelectronic devices. We perform a systematical study on the in-plane optical anisotropy of quasi-one-dimensional PdBr_(2) by using combined measurements of the angle-resolved polarized Raman spectroscopy(ARPRS) and anisotropic optical absorption spectrum. The analyses of ARPRS data validate the anisotropic Raman properties of the PdBr_(2) flake.And anisotropic optical absorption spectrum of PdBr_(2) nanoflake demonstrates distinct optical linear dichroism reversal. Photodetector constructed by PdBr_(2) nanowire exhibits high responsivity of 747 A·W^(-1) and specific detectivity of 5.8×10^(12) Jones. And the photodetector demonstrates prominent polarization-sensitive photoresponsivity under 405-nm light irradiation with large photocurrent anisotropy ratio of 1.56, which is superior to those of most of previously reported quasi-one-dimensional counterparts. Our study offers fundamental insights into the strong optical anisotropy exhibited by PdBr_(2), establishing it as a promising candidate for miniaturization and integration trends of polarization-related applications. 展开更多
关键词 linear dichroism reversal polarization sensitivity ANISOTROPY polarized photodetector
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Long-term thinning decreases the contribution of heterotrophic respiration to soil respiration in subalpine plantations
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作者 Longfei Chen Zhibin He +7 位作者 Wenzhi Zhao Xi Zhu Qin Shen Mingdan Song Zhengpeng Li Junqia Kong Shuping Yang Yuan Gao 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期189-204,共16页
Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicult... Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicultural practice,the long-term impacts of thinning on R_(S) and its heterotrophic and autotrophic respiration components(R_(h) and Ra,respectively)in subalpine plantations are poorly understood,espe-cially in winter.A 3-year field observation was carried out with consideration of winter CO_(2) efflux in middle-aged sub-alpine spruce plantations in northwestern China.A trench-ing method was used to explore the long-term impacts of thinning on Rs,Rn and R_(a).Seventeen years after thinning,mean annual Rs,Rn and R_(a) increased,while the contribu-tion of R_(h) to R_(s) decreased with thinning intensity.Thinning significantly decreased winter R,because of the reduction in R_(n) but had no significant effect on Ra.The temperature sensitivity(Q_(10))of R_(h) and R_(a) also increased with thinning intensity,with lower Q_(10) values for R_(h)(2.1-2.6)than for Ra(2.4-2.8).The results revealed the explanatory variables and pathways related to R_(n) and R_(a) dynamics.Thinning increased soil moisture and nitrate nitrogen(NO_(3)^(-)-N),and the enhanced nitrogen and water availability promoted R_(h) and R_(a) by improving fine root biomass and microbial activity.Our results highlight the positive roles of NO_(3)^(-)-N in stimulating R_(s) components following long-term thinning.Therefore,applications of nitrogen fertilizer are not recommended while thinning subalpine spruce plantations from the perspective of reducing soil CO_(2) emissions.The increased Q_(10) values of R_(s) components indicate that a large increase in soil CO_(2) emissions would be expected following thinning because of more pronounced climate warming in alpineregions. 展开更多
关键词 Heterotrophic respiration Autotrophic respiration Long-term thinning impacts Cold seasons Subalpine plantations Temperature sensitivity
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Impact of effective stress on permeability for carbonate fractured-vuggy rocks
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作者 Ke Sun Huiqing Liu +5 位作者 Juliana Y.Leung Jing Wang Yabin Feng Renjie Liu Zhijiang Kang Yun Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期942-960,共19页
To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of ef... To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(i.e.altered stress conditions)for the fractured core models and the vuggy core models have similar change patterns.The ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy reservoirs.Since each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and 1.Meanwhile,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was proposed.It is proved theoretically that the ESCP of CFVR generally varies between 0 and 1.Additionally,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial model.The concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the weakest.In general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs. 展开更多
关键词 Effective stress PERMEABILITY Carbonate fractured-vuggy rocks Structure characteristics Stress sensitivity
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Aggravation of Cancer,Heart Diseases and Diabetes Subsequent to COVID-19 Lockdown via Mathematical Modeling
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作者 Fatma Nese Efil Sania Qureshi +3 位作者 Nezihal Gokbulut Kamyar Hosseini Evren Hincal Amanullah Soomro 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期485-512,共28页
The global populationhas beenandwill continue to be severely impacted by theCOVID-19 epidemic.The primary objective of this research is to demonstrate the future impact of COVID-19 on those who suffer from other fatal... The global populationhas beenandwill continue to be severely impacted by theCOVID-19 epidemic.The primary objective of this research is to demonstrate the future impact of COVID-19 on those who suffer from other fatal conditions such as cancer,heart disease,and diabetes.Here,using ordinary differential equations(ODEs),two mathematical models are developed to explain the association between COVID-19 and cancer and between COVID-19 and diabetes and heart disease.After that,we highlight the stability assessments that can be applied to these models.Sensitivity analysis is used to examine how changes in certain factors impact different aspects of disease.The sensitivity analysis showed that many people are still nervous about seeing a doctor due to COVID-19,which could result in a dramatic increase in the diagnosis of various ailments in the years to come.The correlation between diabetes and cardiovascular illness is also illustrated graphically.The effects of smoking and obesity are also found to be significant in disease compartments.Model fitting is also provided for interpreting the relationship between real data and the results of thiswork.Diabetic people,in particular,need tomonitor their health conditions closely and practice heart health maintenance.People with heart diseases should undergo regular checks so that they can protect themselves from diabetes and take some precautions including suitable diets.The main purpose of this study is to emphasize the importance of regular checks,to warn people about the effects of COVID-19(including avoiding healthcare centers and doctors because of the spread of infectious diseases)and to indicate the importance of family history of cancer,heart diseases and diabetes.The provision of the recommendations requires an increase in public consciousness. 展开更多
关键词 COVID-19 mathematical modeling CANCER DIABETES heart diseases sensitivity analysis
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A semi-analytical model for coupled flow in stress-sensitive multi-scale shale reservoirs with fractal characteristics
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作者 Qian Zhang Wen-Dong Wang +4 位作者 Yu-Liang Su Wei Chen Zheng-Dong Lei Lei Li Yong-Mao Hao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期327-342,共16页
A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes... A large number of nanopores and complex fracture structures in shale reservoirs results in multi-scale flow of oil. With the development of shale oil reservoirs, the permeability of multi-scale media undergoes changes due to stress sensitivity, which plays a crucial role in controlling pressure propagation and oil flow. This paper proposes a multi-scale coupled flow mathematical model of matrix nanopores, induced fractures, and hydraulic fractures. In this model, the micro-scale effects of shale oil flow in fractal nanopores, fractal induced fracture network, and stress sensitivity of multi-scale media are considered. We solved the model iteratively using Pedrosa transform, semi-analytic Segmented Bessel function, Laplace transform. The results of this model exhibit good agreement with the numerical solution and field production data, confirming the high accuracy of the model. As well, the influence of stress sensitivity on permeability, pressure and production is analyzed. It is shown that the permeability and production decrease significantly when induced fractures are weakly supported. Closed induced fractures can inhibit interporosity flow in the stimulated reservoir volume (SRV). It has been shown in sensitivity analysis that hydraulic fractures are beneficial to early production, and induced fractures in SRV are beneficial to middle production. The model can characterize multi-scale flow characteristics of shale oil, providing theoretical guidance for rapid productivity evaluation. 展开更多
关键词 Multi-scale coupled flow Stress sensitivity Shale oil Micro-scale effect Fractal theory
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A comparison of model choice strategies for logistic regression
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作者 Markku Karhunen 《Journal of Data and Information Science》 CSCD 2024年第1期37-52,共16页
Purpose:The purpose of this study is to develop and compare model choice strategies in context of logistic regression.Model choice means the choice of the covariates to be included in the model.Design/methodology/appr... Purpose:The purpose of this study is to develop and compare model choice strategies in context of logistic regression.Model choice means the choice of the covariates to be included in the model.Design/methodology/approach:The study is based on Monte Carlo simulations.The methods are compared in terms of three measures of accuracy:specificity and two kinds of sensitivity.A loss function combining sensitivity and specificity is introduced and used for a final comparison.Findings:The choice of method depends on how much the users emphasize sensitivity against specificity.It also depends on the sample size.For a typical logistic regression setting with a moderate sample size and a small to moderate effect size,either BIC,BICc or Lasso seems to be optimal.Research limitations:Numerical simulations cannot cover the whole range of data-generating processes occurring with real-world data.Thus,more simulations are needed.Practical implications:Researchers can refer to these results if they believe that their data-generating process is somewhat similar to some of the scenarios presented in this paper.Alternatively,they could run their own simulations and calculate the loss function.Originality/value:This is a systematic comparison of model choice algorithms and heuristics in context of logistic regression.The distinction between two types of sensitivity and a comparison based on a loss function are methodological novelties. 展开更多
关键词 Model choice Logistic regression Logit regression Monte Carlo simulations Sensitivity SPECIFICITY
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Spatial sensitivity to absorption changes for various near-infrared spectroscopy methods:A compendium review
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作者 Giles Blaney Angelo Sassaroli Sergio Fantini 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第4期1-115,共115页
This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three tempo... This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three temporal domains,continuous wave,frequency domain,and time domain,each obtain different optical data types whose changes may be related to effective homogeneous changes in the absorption coefficient.Sensitivity is the relationship between a localized perturbation and the recovered effective homogeneous absorption change.Therefore,spatial sensitivity maps representing the perturbation location can be generated for the numerous optical data types in the three temporal domains.The review first presents a history of the past 30 years of work investigating this sensitivity in optically diffuse media.These works are experimental and theoretical,presenting one-,two-,and three-dimensional sensitivity maps for different Near-Infrared Spectroscopy methods,domains,and data types.Following this history,we present a compendium of sensitivity maps organized by temporal domain and then data type.This compendium provides a valuable tool to compare the spatial sensitivity of various measurement methods and parameters in one document.Methods for one to generate these maps are provided in Appendix A,including the code.This historical review and comprehensive sensitivity map compendium provides a single source researchers may use to visualize,investigate,compare,and generate sensitivity to localized absorption change maps. 展开更多
关键词 Diffuse optics diffusion theory Monte Carlo spatial sensitivity absorption perturbations near-infrared spectroscopy CONTINUOUS-WAVE FREQUENCY-DOMAIN time-domain
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Dinitrophenyl-oxadiazole compounds:Design strategy,synthesis,and properties of a series of new melt-cast explosives
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作者 Bao-long Kuang Ting-wei Wang +6 位作者 Cong Li Mou Sun Qamar-un-Nisa Tariq Chao Zhang Zhi-ming Xie Zu-jia Lu Jian-guo Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期100-107,共8页
Melt-cast explosives are the most widely used energetic materials in military composite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives.In this work,a series o... Melt-cast explosives are the most widely used energetic materials in military composite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives.In this work,a series of dinitrophenyl-oxadiazole compounds were designed and prepared.These compounds have an ideal low melting point(80-97℃),good detonation performance(detonation velocity D=6455-6971 m/s,detonation pressure P=18-19 GPa)and extreme insensitive nature(impact sensitivity≥60 J,friction sensitivity>360 N).All these compounds were well characterized by nuclear magnetic resonance,fourier transform infrared spectroscopy,elemental analysis.Compounds 2,3 were unambiguously confirmed by X-ray single crystal diffraction analysis.As a result,their overall properties are superior to traditional melt-cast explosives trinitrotoluene(TNT)and dinitroanisole(DNAN)which may have excellent potential applications in insensitive melt-cast explosives. 展开更多
关键词 Dinitrophenyl-oxadiazole Melt-cast explosive Low sensitivity
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