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Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury
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作者 Yan Wang Dai Li +12 位作者 Lan Zhang Zhenyu Yin Zhaoli Han Xintong Ge Meimei Li Jing Zhao Shishuang Zhang Yan Zuo Xiangyang Xiong Han Gao qiang liu Fanglian Chen Ping Lei 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第9期2010-2018,共9页
We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repet... We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury. 展开更多
关键词 apoptosis C/EBP homologous protein endoplasmic reticulum stress EXOSOME inositol-requiring enzyme MICROGLIA miR-124-3p neuron repetitive mild traumatic brain injury X-box binding protein 1
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Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis
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作者 Conglin Wang Fangyuan Cheng +9 位作者 Zhaoli Han Bo Yan Pan Liao Zhenyu Yin Xintong Ge Dai Li Rongrong Zhong qiang liu Fanglian Chen Ping Lei 《Neural Regeneration Research》 SCIE CAS 2025年第2期518-532,共15页
Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)... Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes. 展开更多
关键词 AKT ASTROCYTE blood-brain barrier cerebral edema EXOSOMES human-induced pluripotent stem cells intracerebral hemorrhage neural stem cells NEUROINFLAMMATION PI3K
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Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example
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作者 Xiao-Dong Guo qiang liu +3 位作者 Hui-Rong Zhang Xu-Fei Shi Chuan-Yu Qin Zhi-qiang Zhang 《China Geology》 CAS CSCD 2024年第1期116-124,共9页
The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the ... The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars. 展开更多
关键词 Soil heavy metals As+Hg+Cu+Pb+Zn+Ni+Cd Environmental capacity GROUNDWATER Hazard degree Migration flux model Agricultural geological survey engineering Hunchun Basin Jilin Province
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Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures
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作者 qiang liu Wei Xu +7 位作者 Xiaoxi Li Tongyao Zhang Chengbing Qin Fang Luo Zhihong Zhu Shiqiao Qin Mengjian Zhu Kostya S Novoselov 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第1期328-338,共11页
Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of g... Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators. 展开更多
关键词 suspended graphene ultrafast light emitter van der Waals heterostructures thermal radiation electron–phonon interaction
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Mechanical behaviors of backfill-rock composites: Physical shear test and back-analysis
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作者 Jie Xin Quan Jiang +5 位作者 Fengqiang Gong Lang liu Chang liu qiang liu Yao Yang Pengfei Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期807-827,共21页
The shear behavior of backfill-rock composites is crucial for mine safety and the management of surface subsidence.For exposing the shear failure mechanism of backfill-rock composites,we conducted shear tests on backf... The shear behavior of backfill-rock composites is crucial for mine safety and the management of surface subsidence.For exposing the shear failure mechanism of backfill-rock composites,we conducted shear tests on backfill-rock composites under three constant normal loads,compared with the unfilled rock.To investigate the macro-and meso-failure characteristics of the samples in the shear tests,the cracking behavior of samples was recorded by a high-speed camera and acoustic emission monitoring.In parallel with the experimental test,the numerical models of backfill-rock composites and unfilled rock were established using the discrete element method to analyze the continuous-discontinuous shearing process.Based on the damage mechanics and statistics,a novel shear constitutive model was proposed to describe mechanical behavior.The results show that backfill-rock composites had a special bimodal phenomenon of shearing load-deformation curve,i.e.the first shearing peak corresponded to rock break and the second shearing peak induced by the broken of aeolian sand-cement/fly ash paste backfill.Moreover,the shearing characteristic curves of the backfill-rock composites could be roughly divided into four stages,i.e.the shear failure of the specimens experienced:stage I:stress concentration;stage II:crack propagation;stage III:crack coalescence;stage IV:shearing friction.The numerical simulation shows that the existence of aeolian sand-cement/fly ash paste backfill inevitably altered the coalescence type and failure mode of the specimens and had a strengthening effect on the shear strength of backfillrock composites.Based on damage mechanics and statistics,a shear constitutive model was proposed to describe the shear fracture characteristics of specimens,especially the bimodal phenomenon.Finally,the micro-and meso-mechanisms of shear failure were discussed by combining the micro-test and numerical results.The research can advance the better understanding of the shear behavior of backfill-rock composites and contribute to the safety of mining engineering. 展开更多
关键词 Physical simulation Backfill-rock composites Shear failure CRACKING Shear constitutive model
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Sequential neoadjuvant chemotherapy using pegylated liposomal doxorubicin and cyclophosphamide followed by taxanes with complete trastuzumab and pertuzumab treatment for HER2-positive breast cancer: A phase Ⅱ single-arm study
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作者 Yaping Yang Liang Jin +11 位作者 Yudong Li Nanyan Rao Chang Gong Shunrong Li Jiannan Wu Jinghua Zhao Linxiaoxiao Ding Fengxia Gan Jun Zhang Ruifa Feng Zhenzhen liu qiang liu 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2024年第1期55-65,共11页
Objective: Despite cardiotoxicity overlap, the trastuzumab/pertuzumab and anthracycline combination remains crucial due to significant benefits. Pegylated liposomal doxorubicin(PLD), a less cardiotoxic anthracycline, ... Objective: Despite cardiotoxicity overlap, the trastuzumab/pertuzumab and anthracycline combination remains crucial due to significant benefits. Pegylated liposomal doxorubicin(PLD), a less cardiotoxic anthracycline, was evaluated for efficacy and cardiac safety when combined with cyclophosphamide and followed by taxanes with trastuzumab/pertuzumab in human epidermal growth factor receptor-2(HER2)-positive early breast cancer(BC).Methods: In this multicenter, phase II study, patients with confirmed HER2-positive early BC received four cycles of PLD(30-35 mg/m^(2)) and cyclophosphamide(600 mg/m^(2)), followed by four cycles of taxanes(docetaxel,90-100 mg/m^(2) or nab-paclitaxel, 260 mg/m^(2)), concomitant with eight cycles of trastuzumab(8 mg/kg loading dose,then 6 mg/kg) and pertuzumab(840 mg loading dose, then 420 mg) every 3 weeks. The primary endpoint was total pathological complete response(tp CR, yp T0/is yp N0). Secondary endpoints included breast p CR(bp CR),objective response rate(ORR), disease control rate, rate of breast-conserving surgery(BCS), and safety(with a focus on cardiotoxicity).Results: Between May 27, 2020 and May 11, 2022, 78 patients were treated with surgery, 42(53.8%) of whom had BCS. After neoadjuvant therapy, 47 [60.3%, 95% confidence interval(95% CI), 48.5%-71.2%] patients achieved tp CR, and 49(62.8%) achieved bp CR. ORRs were 76.9%(95% CI, 66.0%-85.7%) and 93.6%(95% CI,85.7%-97.9%) after 4-cycle and 8-cycle neoadjuvant therapy, respectively. Nine(11.5%) patients experienced asymptomatic left ventricular ejection fraction(LVEF) reductions of ≥10% from baseline, all with a minimum value of >55%. No treatment-related abnormal cardiac function changes were observed in mean N-terminal pro-BNP(NT-pro BNP), troponin I, or high-sensitivity troponin.Conclusions: This dual HER2-blockade with sequential polychemotherapy showed promising activity with rapid tumor regression in HER2-positive BC. Importantly, this regimen showed an acceptable safety profile,especially a low risk of cardiac events, suggesting it as an attractive treatment approach with a favorable risk-benefit balance. 展开更多
关键词 Breast cancer HER2-positive breast cancer dual HER2 blockade neoadjuvant therapy sequential therapy
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Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction
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作者 Yangtian liu Xiaopeng Yan +2 位作者 qiang liu Tai An Jian Dai 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期328-338,共11页
The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference systems.However,the electromagnetic environment of modern battlefields is complex,and the signal-to-n... The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference systems.However,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio fuzes.To solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is proposed.First,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)signal.Then,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for classification.The DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical algorithms.The trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs. 展开更多
关键词 Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze
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Evaluation of genetic response of mesenchymal stem cells to nanosecond pulsed electric fields by whole transcriptome sequencing
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作者 Jian-Jing Lin Tong Ning +5 位作者 Shi-Cheng Jia Ke-Jia Li Yong-Can Huang qiang liu Jian-Hao Lin Xin-Tao Zhang 《World Journal of Stem Cells》 SCIE 2024年第3期305-323,共19页
BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short du... BACKGROUND Mesenchymal stem cells(MSCs)modulated by various exogenous signals have been applied extensively in regenerative medicine research.Notably,nanosecond pulsed electric fields(nsPEFs),characterized by short duration and high strength,significantly influence cell phenotypes and regulate MSCs differentiation via multiple pathways.Consequently,we used transcriptomics to study changes in messenger RNA(mRNA),long noncoding RNA(lncRNA),microRNA(miRNA),and circular RNA expression during nsPEFs application.AIM To explore gene expression profiles and potential transcriptional regulatory mechanisms in MSCs pretreated with nsPEFs.METHODS The impact of nsPEFs on the MSCs transcriptome was investigated through whole transcriptome sequencing.MSCs were pretreated with 5-pulse nsPEFs(100 ns at 10 kV/cm,1 Hz),followed by total RNA isolation.Each transcript was normalized by fragments per kilobase per million.Fold change and difference significance were applied to screen the differentially expressed genes(DEGs).Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to elucidate gene functions,complemented by quantitative polymerase chain reaction verification.RESULTS In total,263 DEGs were discovered,with 92 upregulated and 171 downregulated.DEGs were predominantly enriched in epithelial cell proliferation,osteoblast differentiation,mesenchymal cell differentiation,nuclear division,and wound healing.Regarding cellular components,DEGs are primarily involved in condensed chromosome,chromosomal region,actin cytoskeleton,and kinetochore.From aspect of molecular functions,DEGs are mainly involved in glycosaminoglycan binding,integrin binding,nuclear steroid receptor activity,cytoskeletal motor activity,and steroid binding.Quantitative real-time polymerase chain reaction confirmed targeted transcript regulation.CONCLUSION Our systematic investigation of the wide-ranging transcriptional pattern modulated by nsPEFs revealed the differential expression of 263 mRNAs,2 miRNAs,and 65 lncRNAs.Our study demonstrates that nsPEFs may affect stem cells through several signaling pathways,which are involved in vesicular transport,calcium ion transport,cytoskeleton,and cell differentiation. 展开更多
关键词 Nanosecond pulsed electric fields Whole transcriptome sequencing Mesenchymal stem cells Genetic response Stem cell engineering
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Retrospective analysis of discordant results between histology and other clinical diagnostic tests on helicobacter pylori infection
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作者 Xiaohua Qi Kevin Kuan +3 位作者 Tony El Jabbour Yungtai Lo qiang liu Yanan Fang 《World Journal of Gastrointestinal Endoscopy》 2024年第2期64-71,共8页
BACKGROUND A reliable test is essential for diagnosing Helicobacter pylori(H.pylori)infection,and crucial for managing H.pylori-related diseases.Serving as an excellent method for detecting H.pylori infection,histolog... BACKGROUND A reliable test is essential for diagnosing Helicobacter pylori(H.pylori)infection,and crucial for managing H.pylori-related diseases.Serving as an excellent method for detecting H.pylori infection,histologic examination is a test that clinicians heavily rely on,especially when complemented with immunohistochemistry(IHC).Additionally,other diagnostic tests for H.pylori,such as the rapid urease test(CLO test)and stool antigen test(SA),are also highly sensitive and specific.Typically,the results of histology and other tests align with each other.However,on rare occasions,discrepancy between histopathology and other H.pylori diagnostic tests occurs.AIM To investigate the discordance between histology and other H.pylori tests,the underlying causes,and the impact on clinical management.METHODS Pathology reports of gastric biopsies were retrieved spanning August 2013 and July 2018.Reports were included in the study only if there were other H.pylori tests within seven days of the biopsy.These additional tests include CLO test,SA,and H.pylori culture.Concordance between histopathology and other tests was determined based on the consistency of results.In instances where histology results were negative while other tests were positive,the slides were retrieved for re-assessment,and the clinical chart was reviewed.RESULTS Of 1396 pathology reports were identified,each accompanied by one additional H.pylori test.The concordance rates in detecting H.pylori infection between biopsy and other tests did not exhibit significant differences based on the number of biopsy fragments.117 discrepant cases were identified.Only 20 cases(9 with CLO test and 11 with SA)had negative biopsy but positive results in other tests.Four cases initially stained with Warthin-Starry turned out to be positive for H.pylori with subsequent IHC staining.Among the remaining 16 true discrepant cases,10 patients were on proton pump inhibitors before the biopsy and/or other tests.Most patients underwent treatment,except for two who were untreated,and two patients who were lost to follow-up.CONCLUSION There are rare discrepant cases with negative biopsy but positive in SA or CLO test.Various factors may contribute to this inconsistency.Most patients in such cases had undergone treatment. 展开更多
关键词 Helicobacter pylori DISCORDANCE Gastric biopsy HISTOLOGY Rapid urease test Stool antigen test Helicobacter pylori culture
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特发性黄斑前膜术后视力与黄斑区形态结构和血流密度的相关性 被引量:3
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作者 张凌 何东林 +4 位作者 刘强 肖旗彬 陈静 乐原 陈彬 《国际眼科杂志》 CAS 北大核心 2023年第3期504-507,共4页
目的:利用光学相干断层扫描血管成像(OCTA)观察特发性黄斑前膜(IMEM)患者术后黄斑区形态结构及血流密度的变化,分析其与视力的相关性。方法:前瞻性研究。连续收集2020-01/2021-07就诊于我院的IMEM患者45例45眼,观察术前、术后1wk,1、3、... 目的:利用光学相干断层扫描血管成像(OCTA)观察特发性黄斑前膜(IMEM)患者术后黄斑区形态结构及血流密度的变化,分析其与视力的相关性。方法:前瞻性研究。连续收集2020-01/2021-07就诊于我院的IMEM患者45例45眼,观察术前、术后1wk,1、3、6mo最佳矫正视力(BCVA)、中央黄斑区厚度(CMT)、中心凹无血管区(FAZ)面积、中心凹视网膜浅层毛细血管丛(SCP)血流密度的变化。结果:与术前比较,纳入患者术后1wk BCVA无明显变化(P>0.05),术后1、3、6mo均明显改善(P<0.05);术后1wk CMT明显增厚(P<0.05),术后1、3、6mo均明显降低(P<0.05);术后1wk,1mo FAZ面积无明显变化(P>0.05),术后3、6mo明显扩大(P<0.05);术后1wk,1、3mo SCP血流密度均无明显变化(P>0.05),术后6mo明显减少(P<0.05)。术后3、6mo纳入患者BCVA与CMT呈正相关(r=0.457、0.615,P=0.032、0.012)。结论:特发性黄斑前膜手术后1mo内视力恢复快,之后趋于平稳,而中心凹形态及血流分布的恢复滞后于视力恢复,且与视力无明显相关性。 展开更多
关键词 黄斑前膜 特发性 玻璃体切割手术 光学相干断层扫描血管成像 微结构
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20mm厚AZ31镁合金厚板搅拌摩擦焊接接头的显微组织演变及强化机制
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作者 刘强 王文 +7 位作者 彭湃 张婷 韩鹏 关肖虎 王智 乔柯 蔡军 王快社 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第11期3295-3308,共14页
采用搅拌摩擦焊焊接20mm厚AZ31镁合金板材,并沿厚度方向分5层对接头的显微组织和力学性能进行表征。结果表明:焊接温度和温降速率的不同导致搅拌区晶粒尺寸不均匀,且在材料流动行为的作用下,接头不同区域形成不同强织构。此外,接头各层... 采用搅拌摩擦焊焊接20mm厚AZ31镁合金板材,并沿厚度方向分5层对接头的显微组织和力学性能进行表征。结果表明:焊接温度和温降速率的不同导致搅拌区晶粒尺寸不均匀,且在材料流动行为的作用下,接头不同区域形成不同强织构。此外,接头各层的屈服强度和抗拉强度从上表面至下表面整体呈逐渐增加的趋势,伸长率沿接头厚度方向首先由9.5%升高至10.5%,然后逐渐降低至6.0%。整体接头的抗拉强度达到母材的88.5%。接头的主要强化机制为细晶强化。 展开更多
关键词 显微组织演变 力学性能 强化机制 搅拌摩擦焊 镁合金 厚板
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Advances in the Application of Perovskite Materials 被引量:3
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作者 Lixiu Zhang Luyao Mei +37 位作者 Kaiyang Wang Yinhua Lv Shuai Zhang Yaxiao Lian Xiaoke liu Zhiwei Ma Guanjun Xiao qiang liu Shuaibo Zhai Shengli Zhang Gengling liu Ligang Yuan Bingbing Guo Ziming Chen Keyu Wei Aqiang liu Shizhong Yue Guangda Niu Xiyan Pan Jie Sun Yong Hua Wu‑qiang Wu Dawei Di Baodan Zhao Jianjun Tian Zhijie Wang Yang Yang Liang Chu Mingjian Yuan Haibo Zeng Hin‑Lap Yip Keyou Yan Wentao Xu Lu Zhu Wenhua Zhang Guichuan Xing Feng Gao Liming Ding 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第10期334-381,共48页
Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allo... Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices(solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices(artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices. 展开更多
关键词 Perovskites Optoelectronic devices Neuromorphic devices Pressure-induced emission
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Facile integration of an Al-rich Al_(1-x)In_(x)N photodetector on free-standing GaN by radio-frequency magnetron sputtering
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作者 刘新科 林之晨 +12 位作者 林钰恒 陈建金 邹苹 周杰 李博 沈龙海 朱德亮 刘强 俞文杰 黎晓华 顾泓 王新中 黄双武 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期591-597,共7页
Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap e... Al_(1-x)In_(x)N, a Ⅲ-nitride semiconductor material, is currently of great research interest due to its remarkable physical properties and chemical stability. When the Al and In compositions are tuned, its band-gap energy varies from 0.7 eV to 6.2 eV, which shows great potential for application in photodetectors. Here, we report the fabrication and performance evaluation of integrated Al_(1-x)In_(x)N on a free-standing GaN substrate through direct radio-frequency magnetron sputtering.The optical properties of Al_(1-x)In_(x)N will be enhanced by the polarization effect of a heterostructure composed of Al_(1-x)In_(x)N and other Ⅲ-nitride materials. An Al_(1-x)In_(x)N/Ga N visible-light photodetector was prepared by semiconductor fabrication technologies such as lithography and metal deposition. The highest photoresponsivity achieved was 1.52 A·W^(-1)under 365 nm wavelength illumination and the photodetector was determined to have the composition Al0.75In0.25N/GaN.A rise time of 0.55 s was observed after transient analysis of the device. The prepared Al_(1-x)In_(x)N visible-light photodetector had a low dark current, high photoresponsivity and fast response speed. By promoting a low-cost, simple fabrication method,this study expands the application of ternary alloy Al_(1-x)In_(x)N visible-light photodetectors in optical communication. 展开更多
关键词 Ali-xIn N PHOTODETECTOR GaN radio-frequency magnetron sputtering ternary alloy
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Orchid diversity and distribution pattern in karst forests in eastern Yunnan Province,China
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作者 qiang liu Xunfeng Wu +4 位作者 Haitao Xing Kuanbo Chi Wenhua Wang Liang Song Xiaoke Xing 《Forest Ecosystems》 SCIE CSCD 2023年第3期348-356,共9页
Global biodiversity loss and mass extinction of species have raised serious global concerns,especially in fragile ecosystems.Karst forest,a well-known fragile ecosystem,is served as a natural laboratory for biogeograp... Global biodiversity loss and mass extinction of species have raised serious global concerns,especially in fragile ecosystems.Karst forest,a well-known fragile ecosystem,is served as a natural laboratory for biogeographical,ecological,evolutionary,and taxonomic research.However,species richness and distribution patterns in karst forests largely remain unclear.Orchidaceae has been regarded as the“flagship”group of plant diversity.In this study,we use Wanfengshan Nature Reserve in southeast Yunnan,China,as a model to determine the conservation status of orchids in the karst forest by conducting systematic field surveys in the past three years from 2019 to 2022.In total,we identified 78 orchid species in 35 genera in Wanfengshan Nature Reserve.The dominant species were Bulbophyllum andersonii,Eria coronaria,Nervilia mackinnonii and Paphiopedilum micranthum.Multiple life forms were also observed,including epiphyte(14.29%),facultative epiphyte(18.18%),lithophyte(23.38%),and terrestrial(44.15%).Orchid species richness showed a bimodal pattern varied with altitude,the higher richness was recorded at 1,500-1,600 and 1,200-1,300 m,while the minimum was below 1,100 m.Each independent hill is rich in orchid species including‘endemic’species.A total of 25(33.8%)orchid species were considered threatened by the Redlist of Chinese Vascular Plants(Qin et al.,2017),including 3 CR species,5 EN species and 17 VU species.We call for more research addressing the mechanisms of ecological adaption,mycorrhizal interactions,and pollination of orchids in karst forests,and effective ways for recovery and conservation of orchids. 展开更多
关键词 Orchid diversity Limestone forest Resource investigation Threatened status Orchid conservation
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Conjugated polymerized bimetallic phthalocyanine based electrocatalyst with Fe-N_(4)/Co-N_(4) dual-sites synergistic effect for zinc-air battery
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作者 Shuaifeng Wang Zhongfang Li +5 位作者 Wenjie Duan Peng Sun Jigang Wang qiang liu Lei Zhang Yanqiong Zhuang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第11期41-53,I0002,共14页
The bifunctional oxygen catalyst is essential for zinc-air batteries(ZABs).Here,an efficient bifunctional oxygen catalyst,PPcFeCo/3D-G,is obtained throughπ-πinteraction between the conjugated polymerized iron-cobalt... The bifunctional oxygen catalyst is essential for zinc-air batteries(ZABs).Here,an efficient bifunctional oxygen catalyst,PPcFeCo/3D-G,is obtained throughπ-πinteraction between the conjugated polymerized iron-cobalt phthalocyanine(PPcFeCo)with excellent thermal stability and three-dimensional graphene(3D-G).The bimetallic synergistic effect of PPcFeCo,verified by DFT(Density functional theory)calculation,andπ-πinteractions enhances the catalytic activity and durability of the PPcFeCo/3D-G.Regarding electrochemical performance,the PPcFeCo/3D-G with a high electron transfer number(3.98,@0.768 V vs.RHE)has excellent half-wave potential(E_(1/2)=0.890 V vs.RHE)and exhibits outstanding reversibility(ΔE=0.700 V,ΔE=Ej=10-E_(1/2)).The liquid ZAB(LZAB)employed PPcFeCo/3D-G displays a high power density(222 m W cm^(-2)),a specific capacity(792 m A h g-1),and excellent durability(120 h).This work has guiding significance for the preparation of high-efficiency bifunctional catalysts. 展开更多
关键词 Zn-airbattery Bifunctional oxygen catalysts Polymerized iron-cobalt phthalocyanine Bimetallic synergy π-πinteraction
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Tectonic boundaries in the South China Sea from aeromagnetic signature
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作者 Yao LUO Hang YIN +5 位作者 qiang liu Jingmin LI Shihua liu Wei GAO Rui LI Yi YANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第2期550-561,共12页
Magnetic data has been widely applied in the tectonic division.High-resolution magnetic data were used to analyze the geotectonic zoning of the South China Sea.Based on the newly compilated magnetic data,the processin... Magnetic data has been widely applied in the tectonic division.High-resolution magnetic data were used to analyze the geotectonic zoning of the South China Sea.Based on the newly compilated magnetic data,the processing results and the distribution of known faults,we consider that the U-shaped line approximately along the South China Sea national boundary of China shown in the magnetic map is a significant geological and geophysical boundary.We first described the linear characteristics of the magnetic data and then applied pseudo-gravity,Euler deconvolution,tilt derivatives,and the texture segmentation method to process the data.Results show that the dividing line between the South China Sea and the surrounding blocks is approximately along this U-shaped line.The dividing line between the South China domain and the South China Sea domain is along with the Dongsha Islands to Xisha Trough,which is different from the previous geophysical zoning results.Our results are almost consistent with those of the gravity data indicating roughly the tectonic zonation along the U-shaped line. 展开更多
关键词 South China Sea U-shaped line tectonic zoning aeromagnetic map texture segmentation
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Revising the H_(2)^(16)O line-shape parameters around 1.1μm based on the speed-dependent Nelkin–Ghatak profile and the Hartmann–Tran profile
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作者 张惠 郑健捷 +6 位作者 刘强 朱文越 钱仙妹 江贵生 查申龙 张启磊 马宏亮 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期305-311,共7页
Accurate spectroscopic data for H_(2)^(16)O in the 1.1μm region are particularly important for the study of Earth's atmosphere.The pure water vapor molecular spectra were measured based on direct laser absorption... Accurate spectroscopic data for H_(2)^(16)O in the 1.1μm region are particularly important for the study of Earth's atmosphere.The pure water vapor molecular spectra were measured based on direct laser absorption spectroscopy using a narrow line-width external cavity diode laser combined with a high-precision Fabry-Pérot etalon.A total of 31 H_(2)^(16)O transitions were studied for the first time by using the speed-dependent Nelkin-Ghatak profile and the Hartmann-Tran profile.From an accurate line-shape analysis,we obtained the line intensities and the self-broadening coefficients,and they are compared with the available data reported in the HITRAN 2016 database and the HITRAN 2020 database.Finally,we obtained information on the influence of Dicke narrowing,as well as the correlations between Dicke narrowing and speed dependence,and of speed-dependent effects. 展开更多
关键词 pure water vapor molecule the speed-dependent Nelkin–Ghatak profile the Hartmann–Tran profile line intensities
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Micro-Expression Recognition Based on Spatio-Temporal Feature Extraction of Key Regions
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作者 Wenqiu Zhu Yongsheng Li +1 位作者 qiang liu Zhigao Zeng 《Computers, Materials & Continua》 SCIE EI 2023年第10期1373-1392,共20页
Aiming at the problems of short duration,low intensity,and difficult detection of micro-expressions(MEs),the global and local features of ME video frames are extracted by combining spatial feature extraction and tempo... Aiming at the problems of short duration,low intensity,and difficult detection of micro-expressions(MEs),the global and local features of ME video frames are extracted by combining spatial feature extraction and temporal feature extraction.Based on traditional convolution neural network(CNN)and long short-term memory(LSTM),a recognition method combining global identification attention network(GIA),block identification attention network(BIA)and bi-directional long short-term memory(Bi-LSTM)is proposed.In the BIA,the ME video frame will be cropped,and the training will be carried out by cropping into 24 identification blocks(IBs),10 IBs and uncropped IBs.To alleviate the overfitting problem in training,we first extract the basic features of the preprocessed sequence through the transfer learning layer,and then extract the global and local spatial features of the output data through the GIA layer and the BIA layer,respectively.In the BIA layer,the input data will be cropped into local feature vectors with attention weights to extract the local features of the ME frames;in the GIA layer,the global features of the ME frames will be extracted.Finally,after fusing the global and local feature vectors,the ME time-series information is extracted by Bi-LSTM.The experimental results show that using IBs can significantly improve the model’s ability to extract subtle facial features,and the model works best when 10 IBs are used. 展开更多
关键词 Micro-expression recognition attention mechanism long and short-term memory network transfer learning identification block
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Comparison on crack propagation under tension at 150℃ of Mg-2Zn-1.5Mn alloy sheets with and without crack notch
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作者 qiang liu Jiangfeng Song +5 位作者 Qiuyan Shen Liangyin Wu Bin Jiang Weimin Gan Kaihong Zheng Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第5期1536-1548,共13页
Generally,edge crack of rolled magnesium alloy sheets initiates in the RD(rolling direction)-ND(normal direction)plane and then propagate in the RD-TD(transverse direction)plane.Hence,the Mg-2Zn-1.5Mn(ZM21)alloy sheet... Generally,edge crack of rolled magnesium alloy sheets initiates in the RD(rolling direction)-ND(normal direction)plane and then propagate in the RD-TD(transverse direction)plane.Hence,the Mg-2Zn-1.5Mn(ZM21)alloy sheets with and without crack notch were designed to carry out in-situ tensile experiments under 150℃(the same temperature of rolling),with the aim to understand their crack propagation mechanism.The scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)techniques were utilized to reveal microstructural evolution in real time at designated displacements.The results show that the prismatic slip,basal slip,and extension twining play synergistic role in coordinating strain during the tensile process in ZM21 alloy sheet at 150℃.In both tensile samples with and without crack notch,localized strain is mainly concentrated at relatively fine grain area and the grain boundaries or triple junctions of the grains with large basal Schmid factor(SF)difference,which eventually leads to severe surface roughening and subsequent crack initiation.Compared with the sample without crack notch,the pre-cracked sample exhibits severer deformation at the crack tip due to strain concentration.Strain gradient distribution is observed at the crack tip region in the pre-cracked sample.The crack propagation path of the sample with pre-crack is identified and the underlying mechanism is also discussed. 展开更多
关键词 ZM21 alloy In-situ tensile test Crack propagation path Crack notch
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Ensuring User Privacy and Model Security via Machine Unlearning: A Review
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作者 Yonghao Tang Zhiping Cai +2 位作者 qiang liu Tongqing Zhou qiang Ni 《Computers, Materials & Continua》 SCIE EI 2023年第11期2645-2656,共12页
As an emerging discipline,machine learning has been widely used in artificial intelligence,education,meteorology and other fields.In the training of machine learning models,trainers need to use a large amount of pract... As an emerging discipline,machine learning has been widely used in artificial intelligence,education,meteorology and other fields.In the training of machine learning models,trainers need to use a large amount of practical data,which inevitably involves user privacy.Besides,by polluting the training data,a malicious adversary can poison the model,thus compromising model security.The data provider hopes that the model trainer can prove to them the confidentiality of the model.Trainer will be required to withdraw data when the trust collapses.In the meantime,trainers hope to forget the injected data to regain security when finding crafted poisoned data after the model training.Therefore,we focus on forgetting systems,the process of which we call machine unlearning,capable of forgetting specific data entirely and efficiently.In this paper,we present the first comprehensive survey of this realm.We summarize and categorize existing machine unlearning methods based on their characteristics and analyze the relation between machine unlearning and relevant fields(e.g.,inference attacks and data poisoning attacks).Finally,we briefly conclude the existing research directions. 展开更多
关键词 Machine learning machine unlearning privacy protection trusted data deletion
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