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Gastric motility functional study based on electrical bioimpedance measurements and simultaneous electrogastrography 被引量:9
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作者 zhang-yong LI Chao-shi REN +2 位作者 Shu ZHAO Hong SHA Juan DENG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第12期983-989,共7页
For some time now,the research on gastric motility and function has fallen behind in the amount of research on gastric endocrine,exocrine secretion,and gastric morphology.In this paper,a noninvasive method to study ga... For some time now,the research on gastric motility and function has fallen behind in the amount of research on gastric endocrine,exocrine secretion,and gastric morphology.In this paper,a noninvasive method to study gastric motility was developed,taking bioimpedance measurements over the gastric area simultaneously with the electrogastrography(EGG).This is based on the concept of observing and analyzing simultaneously the intrinsic electrical gastric activity(basic electric rhythm) and the mechanical gastric activity.Additionally,preliminary clinical studies of healthy subjects and subjects with functional dyspepsia(FD) and gastritis were carried out.The impedance gastric motility(IGM) measurements of the healthy and FD subjects were compared,along with the studies of the FD subjects before treatment and after one week and three weeks of treatment.We also compared IGM measurements of healthy subjects and subjects with erosive gastritis,along with the studies of the subjects with erosive gastritis before treatment and after one week of treatment.Results show that FD subjects have poor gastric motility(P<0.01).After a week of treatment,the gastric motility of FD subjects was not yet improved although the EGG had returned to normal by this time.By three weeks of treatment,the regular IGM rhythm returned in FD subjects.There was a significant difference of IGM parameters between the gastritis and healthy subjects(P<0.05).The EGG rhythm of the gastritis subjects returned to normal at one week post-treatment,while IGM parameters showed a trend to improvement(P>0.05),These results suggest the possibility of clinic application of the proposed method. 展开更多
关键词 Gastric motility Electrical bioimpedance ELECTROGASTROGRAPHY Functional dyspepsia GASTRITIS
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棱形石墨烯纳米孔道内离子传输性能的分子动力学模拟
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作者 张勇 蒋更平 《原子与分子物理学报》 北大核心 2024年第5期46-60,共15页
纳米通道的尺寸、结构和表面化学对其内部溶液的分布结构和输运性质有着重大影响.本文研究了一种全新的菱形石墨烯纳米通道.这种理想的通道与最近被广泛研究的金属有机框架材料(MOF)的内部结构类似,有着与传统的碳纳米管截然不同的内部... 纳米通道的尺寸、结构和表面化学对其内部溶液的分布结构和输运性质有着重大影响.本文研究了一种全新的菱形石墨烯纳米通道.这种理想的通道与最近被广泛研究的金属有机框架材料(MOF)的内部结构类似,有着与传统的碳纳米管截然不同的内部结构.本文使用分子动力学模拟的方法研究在不同尺寸的菱形石墨烯纳米通道内的KCl溶液的性质,并将其与同尺寸的单壁碳纳米管进行了比较.研究结果表明在小孔道内(<20)其内部的溶液结构呈现若干个密度极高的聚集区域,即出现了结晶化的趋势.这一研究结果,将为MOF的结构设计提供思路,从而有望实现类似于生物离子通道的高选择性和高传输能力. 展开更多
关键词 纳米通道 分子动力学模拟 离子输运
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Non-leguminous winter cover crop and nitrogen rate in relation to double rice grain yield and nitrogen uptake in Dongting Lake Plain, Hunan Province, China 被引量:4
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作者 ZHU Bo YI Li-xia +5 位作者 XU He-shui GUO Li-mei HU Yue-gao ZENG Zhao-hai CHEN Fu LIU zhang-yong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第11期2507-2514,共8页
Annual ryegrass(Lolium multiflorum Lam.), a non-leguminous winter cover crop, has been adopted to absorb soil native N to minimize N loss from an intensive double rice cropping system in southern China, but a little... Annual ryegrass(Lolium multiflorum Lam.), a non-leguminous winter cover crop, has been adopted to absorb soil native N to minimize N loss from an intensive double rice cropping system in southern China, but a little is known about its effects on rice grain yield and rice N use efficiency. In this study, effects of ryegrass on double rice yield, N uptake and use efficiency were measured under different fertilizer N rates. A 3-year(2009–2011) field experiment arranged in a split-plot design was undertaken. Main plots were ryegrass(RG) as a winter cover crop and winter fallow(WF) without weed. Subplots were three N treatments for each rice season: 0(N_0), 100(N_(100)) and 200 kg N ha–1(N_(200)). In the 3-year experiment, RG reduced grain yield and plant N uptake for early rice(0.4–1.7 t ha–1 for grain yield and 4.6–20.3 kg ha–1 for N uptake) and double rice(0.6–2.0 t ha–1 for grain yield and 6.3–27.0 kg ha–1 for N uptake) when compared with WF among different N rates. Yield and N uptake decrease due to RG was smaller in N_(100) and N_(200) plots than in N_0 plots. The reduction in early rice grain yield in RG plots was associated with decrease number of panicles. Agronomic N use efficiency and fertilizer N recovery efficiency were higher in RG plots than winter fallow for early rice and double rice among different N rates and experimental years. RG tended to have little effect on grain yield, N uptake, agronomic N use efficiency, and fertilizer N recovery efficiency in the late rice season. These results suggest that ryegrass may reduce grain yield while it improves rice N use efficiency in a double rice cropping system. 展开更多
关键词 double rice grain yield N uptake N use efficiency winter cover crop
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Protective Effects of Different Hypothermal Preservation Solutions on Structure and Function of Isolated Rat Arteries
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作者 zhang-yong REN Shao-cheng LYU +4 位作者 Han-xuan WANG Jing WANG Lin ZHOU Qiang HE Ren LANG 《Current Medical Science》 SCIE CAS 2023年第4期768-778,共11页
Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,imp... Objective:With the increasing application of vascular reconstruction in surgical procedures,allogeneic vessels are becoming more popular in clinical practice due to their abundant sources,precise diameter matching,improved histocompatibility,and higher long-term patency rate.This study aimed to investigate the protective effect of various preservation solutions on the function and structure of the isolated rat abdominal aorta preserved under hypothermal conditions.Methods:The study utilized a total of 150 Sprague-Dawley(SD)rats,with 144 rats allocated to the experimental groups and 6 rats allocated to the control groups.The abdominal aorta of the rats was chosen as the subject of our research.The aorta in the experimental groups were randomly assigned to 4 groups:University of Wisconsin(UW)solution group,histidine-tryptophan-ketoglutarate(HTK)solution group,normal saline(NS)group,and sodium lactate Ringer's solution(RS)group.Samples were subjected to examination after preservation periods of 1 day,3 days,5 days,7 days,14 days,30 days,and 90 days.Evaluation of vascular physiological function involved detecting and assessing vasoconstriction ability and measuring cell viability through the MTT test.Evaluation of the vascular wall structure involved tension tolerance tests and pathological staining.Results:The pathogen-positive rate in the HTK group and NS group at 1 month was 16.7%.Regarding the vascular skeleton structure,both the UW group and HTK group exhibited intact structures after 2 weeks of preservation,with slightly edematous collagen and elastic fibers,which was significantly better than that of the NS group and RS group.In terms of cell activity and contractile function,all preservation groups showed similar effects within 2 weeks.However,after 2 weeks,the UW group showed the most favorable preservation effect(P<0.05).In terms of vascular tension,different groups exhibited similar effects within 1 week.However,after 2 weeks,the UW group showed the best preservation effect(P<0.05).Conclusion:All 4 types o 展开更多
关键词 rat model allogeneic artery preservation solution vascular preservation technique vascular reconstruction
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Functional reconstruction of ischemic contracture in the lower limb 被引量:1
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作者 TANG Hao zhang Shao-cheng TAN zhang-yong ZHU Hong-wei zhang Qiu-lin LI Ming 《Chinese Journal of Traumatology》 CAS 2011年第2期96-99,共4页
Objective: To discuss the method of functional reconstruction of ischemic contracture in the lower limb and propose a classification protocol for ischemic contracture in the lower limb based on its severity and progn... Objective: To discuss the method of functional reconstruction of ischemic contracture in the lower limb and propose a classification protocol for ischemic contracture in the lower limb based on its severity and prognosis. Methods: Atotal of 42 patients with ischemic contracture in the lower limb were included in this study. According to different types of disturbance and degrees of severity, surgical reconstructions consisting of nerve decompression, tendon lengthening or transfer, intrinsic foot muscle release and sural-tibial nerve anastomosis were performed in every patient. Results: Postoperatively, all patients were able to walk on flat ground. Drop foot was corrected in 10 patients, and 5 patients still felt some difficulty during stair activity. Split Achilles tendon transfer to flexor hallucis longus tendon was performed in 12 patients, and their walking stability was improved. Seven patients accepted ipsilateral suraltibial nerve anastomosis, and sensitivity recovery reached to S2 in 2 patients and S3 in 5 patients. Conclusions: Iscbemic contracture in the lower limb is a devastating complication after lower limb trauma. The prevention of contracture is much more important than the treatment of an established contracture. Split Achilles tendon transfer to flexor hallucis longus tendon and sural-tibial nerve anastomosis, which was initially implemented by us, could improve the functional recovery of ischemic contracture in lower limbs, and thus provides a new alternative for functional reconstruction of ischemic contracture in the lower limb. 展开更多
关键词 Ischemic contracture CLASSIFICATION Recovery of function
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Electrical bioimpedance gastric motility measurement based on an electrical-mechanical composite mechanism 被引量:2
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作者 Shu Zhao Hong Sha +1 位作者 zhang-yong Li, Chao-Shi Ren 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第25期3282-3287,共6页
AIM: To introduce a bioimpedance gastric motility mea- surement method based on an electrical-mechanical composite concept and a preliminary clinical application. METHODS: A noninvasive gastric motility measure- men... AIM: To introduce a bioimpedance gastric motility mea- surement method based on an electrical-mechanical composite concept and a preliminary clinical application. METHODS: A noninvasive gastric motility measure- ment method combining electrogastrograrn (EGG) and impedance gastric motility (IGM) test was used. Prelim- inary clinical application studies of patients with func- tional dyspepsia (FD) and gastritis, as well as healthy controls, were carried out. Twenty-eight FD patients (mean age 40.9±9.7 years) and 40 healthy volun- teers (mean age 30.9±7.9 years) were involved. IGM spectrum was measured for both the healthy subjects and FD patients, and outcomes were compared in the FD patients before treatment and 1 wk and 3 wk after treatment. IGM parameters were obtained from 30 erosive gastritis patients (mean age 50.5±13.0 years) and 40 healthy adults, and IGM and EGG results were compared in the gastritis patients before treatment and 1 wk after treatment.RESULTS: There were significant differences in the IGM parameters between the FD patients and healthy subjects, and FD patients had a poorer gastric motility [percentage of normal frequency (PNF) 70.8±25.5 in healthy subjects and 28.3 =t= 16.9 in FD patients, P 〈 0.01]. After 1 wk administration of domperidone 10 mg, tid, the gastric motility of FD patients was not im- proved, although the EGG of the patients had returned to normal. After 3 wk of treatment, the IGM rhythm of the FD patients became normal. There was a significant difference in IGM parameters between the two groups (PNF 70.4:1:25.5 for healthy subjects and 36.1 4- 21.8 for gastritis patients, P 〈 0.05). The EGG rhythm of the gastritis patients returned to normal (frequency insta- bility coefficient 2.22±0.43 before treatment and 1.77 :t: 0.19 one wk after treatment, P 〈 0.05) after 1 wk of treatment with sodium rabeprazole tablets, 10 mg, qd, po, qm, while some IGM parameters showed a tenden- cy toward improvement but had not reached s 展开更多
关键词 Gastric motility Electrical bioimpedance Electrical-mechanical composite ELECTROGASTROGRAM
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社交电商涉罪行为的刑法规制——以“花生日记”传销案为例 被引量:1
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作者 张勇 郑天城 《时代法学》 2021年第4期8-18,共11页
互联网在赋予传统电子商务新属性的同时,也带来了新的机遇和挑战。作为电子商务的一种新的衍生模式,社交电商在蓬勃发展的同时,也蕴含了一系列的刑事风险。为了平衡电子商务的创新效用和风险管控,对于社交电商刑事风险的治理,应当秉持... 互联网在赋予传统电子商务新属性的同时,也带来了新的机遇和挑战。作为电子商务的一种新的衍生模式,社交电商在蓬勃发展的同时,也蕴含了一系列的刑事风险。为了平衡电子商务的创新效用和风险管控,对于社交电商刑事风险的治理,应当秉持行政规制先行、刑法谨慎介入的谦抑理念,同时确立投资者权益先于金融风险防控的法益保护观念,充分利用行政立法和刑法解释机制,促进社交电商的合规化发展。基于实质解释的立场,社交电商本质上仍属于数字经济创新,在认定其涉罪行为时应当极其谨慎,只有利用社交电商进行非法经营、组织、领导传销活动、侵犯公民个人信息等违法犯罪活动,并达到严重扰乱市场经济秩序危害程度的,才应纳入刑事评价的范畴。 展开更多
关键词 社交电商 刑事风险 出罪路径 实质解释
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Prognosis of Liver Transplantation for Hepatocellular Carcinoma in Terms of Different Criteria:A Single Center Experience
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作者 Shao-cheng LYU Jing WANG +2 位作者 zhang-yong REN Di CAO Qiang HE 《Current Medical Science》 SCIE CAS 2022年第3期548-554,共7页
Objective Patients undergoing liver transplantation for hepatocellular carcinoma(HCC)within the Milan criteria have an excellent outcome.We developed a program to analyze and prove that the Milan criteria can be expan... Objective Patients undergoing liver transplantation for hepatocellular carcinoma(HCC)within the Milan criteria have an excellent outcome.We developed a program to analyze and prove that the Milan criteria can be expanded safely and effectively.Methods We retrospectively reviewed 117 HCC patients treated with liver transplantation between January 2013 and December 2017.Patients were grouped according to the Milan criteria,the University of California,San Francisco(UCSF)criteria,Up-to-seven criteria and Hangzhou criteria.Tumor-free and overall survival rates were investigated with a Kaplan-Meier analysis.Multivariable regression Cox models produced survival estimates for the patients that exceeded the Milan criteria.Results The 1-year,3-year and 5-year overall survival rates of patients fulfilling the Milan criteria(n=44)were 100%,87.5%and 78.9%,respectively.Compared with the Milan criteria,the UCSF criteria(n=50),Up-to-seven criteria(n=51)and Hangzhou criteria(n=86)provided an expansion of 13.6%,15.9%and 95.9%,respectively.The 1-year,3-year and 5-year overall survival rates of patients fulfilling UCSF criteria,Up-to-seven criteria and Hangzhou criteria were 96.0%,84.9%,76.9%;96.1%,85.2%,77.6%and 97.7%,83.9%,66.7%,respectively(P>0.05).Multifactor Cox regression showed that tumor diameter and microvascular invasion were independent risk factors for survival in patients that exceeded the Milan criteria.Conclusion Compared with the Milan criteria,the Hangzhou criteria can safely expand the scope of liver transplantation for HCC to a certain extent.By contrast,the UCSF criteria and Up-to-seven criteria result in a limited number of patients which need further expansion.Tumor diameter and microvascular invasion were the independent risk factors for survival in patients that exceeded the Milan criteria. 展开更多
关键词 liver transplantation hepatocellular carcinoma SURVIVAL Milan criteria
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Visible Light Emission in Highly Charged Kr^(17+) Ions Colliding with an Al Surface
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作者 YANG Zhi-Hu XU Qiu-Mei +2 位作者 GUO Yi-Pan WU Ye-Hong SONG zhang-yong 《Chinese Physics Letters》 SCIE CAS CSCD 2013年第1期61-62,共2页
We report light emission during the bombardment of Kr^(17+) ions on an Al surface in the wavelength range 300–700 nm.The three spectral lines of the sputtered Al atoms belong to transitions of Al I–at 309.26,Al I–4... We report light emission during the bombardment of Kr^(17+) ions on an Al surface in the wavelength range 300–700 nm.The three spectral lines of the sputtered Al atoms belong to transitions of Al I–at 309.26,Al I–4s 2S1/2 at 394.72 and Al I 3p^(2)P°_(3/2)–4_(s)^(2)S_(1/2) at 396.50 nm.During the neutralization process,the seven spectral lines of Kr I and Kr II from the incident ion of Kr^(17+)attribute to transitions of Kr I 5p^(2)[3/2]2–7d^(2)[1/2]°1 at 616.33,Kr II 5s ^(2)D_(5/2)–5p ^(2)D°_(3/2) at 410.86,Kr II 5p 4P°_(5/2)–6s 4P_(5/2) at 430.58,Kr II 4d^(2)D_(3/2)–4f ^(2)[3]°_(5/2) at 434.42,Kr II 4d ^(4)D_(1/2)–5p ^(2)S°_(1/2) at 485.80,Kr II 4p ^(4)S_(3/2)–6s ^(4)P°_(3/2) at 618.57 and Kr II 5p 4P°_(3/2)–4d ^(2)D_(5/2) at 656.41 nm.Light emissions of sputtered species depend on energy of the incident ions deposited on the target surface atoms.Light emissions of the neutralized projectiles are formed due to many electrons of the conduction band of the solid surface captured in excited states of the incident ion. 展开更多
关键词 INCIDENT TRANSITIONS
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Measurements of the Spectrum of Singly Ionized Argon between 320 and 520 nm
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作者 YANG Zhao-Rui YUAN Ping +2 位作者 SONG zhang-yong XU Qiu-Mei YANG Zhi-Hu 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第1期98-101,共4页
We report beam-foil measurements of the spectrum for Ar 1Ⅱ.Totally 56 lines are measured.Most of them are mainly ascribed to 3d-4p,4s-4p,4p-4d and 4p-5s resonance transitions.These spectral lines are identified,among... We report beam-foil measurements of the spectrum for Ar 1Ⅱ.Totally 56 lines are measured.Most of them are mainly ascribed to 3d-4p,4s-4p,4p-4d and 4p-5s resonance transitions.These spectral lines are identified,among which 16 lines are new and accurately measured.Analyses of the spectra are based on a comparison with the other experimental results and calculated vaJues. 展开更多
关键词 TRANSITIONS SPECTRUM BEAM
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城镇化与农业全要素生产率提升:异质性与空间效应 被引量:50
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作者 武宵旭 葛鹏飞 徐璋勇 《中国人口·资源与环境》 CSSCI CSCD 北大核心 2019年第5期149-156,共8页
农业过剩劳动力的城镇化流动有助于改善农业资源配置效率,实现全要素生产率的增长,进而推动农业发展质量,实现乡村振兴战略。本文基于SBM-DDF和Malmquist-Luenberger生产率指数,在测算农业过剩劳动力的基础上,从常住城镇化和就业城镇化... 农业过剩劳动力的城镇化流动有助于改善农业资源配置效率,实现全要素生产率的增长,进而推动农业发展质量,实现乡村振兴战略。本文基于SBM-DDF和Malmquist-Luenberger生产率指数,在测算农业过剩劳动力的基础上,从常住城镇化和就业城镇化视角分别考察了其对农业全要素生产率的差异性影响。研究发现:①地区间的农业劳动力要素过剩表现出较大差异。具体,中部地区的农业过剩劳动力高于东部和西部,粮食主产区的过剩量高于主销区和平衡区。②整体上,常住城镇化和就业城镇化对农业全要素生产率均表现出促进作用。分地区显示,常住城镇化的促进作用对西部地区最为明显,其次为东部和西部;就不同粮食功能区而言,其对粮食平衡区的促进作用最大,然后是主销区和主产区。③区分不同产业就业城镇化对农业全要素生产率的影响,发现相比于第二产业就业城镇化,第三产业就业城镇化对农业全要素生产率的正向影响更大;进一步地,第二、三产业就业城镇化对东部和主销区的农业全要素生产率影响不显著,对其余区域均有着显著地正向影响。④空间分析表明,就业城镇化具有正向的空间溢出效应,但常住城镇化则不存在;实现"就业"和"身份"的双重改变,是实现农业过剩劳动力持久"转身"的决定因素。政策启示在于,本地城镇化是解决农业过剩劳动力的首选;关注包容性社会政策设计,积极引导农业过剩劳动力城镇服务业就业,不失为改善现阶段城乡社会鸿沟,强化非农"转身"稳定性,实现乡村振兴计划的可行方案。 展开更多
关键词 城镇化 农业全要素生产率 劳动力转移 空间效应 异质性
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数字金融对经济发展与生态环境协同性的影响 被引量:38
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作者 刘潭 徐璋勇 张凯莉 《现代财经(天津财经大学学报)》 CSSCI 北大核心 2022年第2期21-36,共16页
数字金融为促进经济与生态环境协调发展提供了新的动力和契机。以协调发展为研究视角,基于2011-2018年中国285个地级市数据,从理论和实证两方面探究了数字金融对经济发展与生态环境协同性的影响及其内在机理。研究发现:城市尺度上,经济... 数字金融为促进经济与生态环境协调发展提供了新的动力和契机。以协调发展为研究视角,基于2011-2018年中国285个地级市数据,从理论和实证两方面探究了数字金融对经济发展与生态环境协同性的影响及其内在机理。研究发现:城市尺度上,经济发展与生态环境的协同性呈动态上升趋势,空间分布存在"东高、中西低"的特征。数字金融能够有效提升经济发展与生态环境的协同性。对于等级较高的城市和非资源型城市,数字金融具有更强的协同驱动效果。机制分析表明技术创新、产业升级和投资调整是数字金融影响经济与生态环境协调发展的重要传导路径,数字金融通过促进科技成果转化、产业结构优化和投资效率提升,推动经济绿色转型,减轻对环境的不良影响,从而助力经济与环境协调发展。结论启示应强化金融市场与环保产业的双向联动,借助数字科技和信息平台,有效发挥数字金融的"协调引导"效应。 展开更多
关键词 数字金融 经济发展 生态环境 协调发展
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稻虾共作模式下稻田土壤氨氧化微生物丰度和群落结构的特征 被引量:32
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作者 王蓉 朱杰 +1 位作者 金涛 刘章勇 《植物营养与肥料学报》 CAS CSCD 北大核心 2019年第11期1887-1899,共13页
【目的】研究稻虾共作模式下土壤氨氧化微生物数量、群落多样性及群落结构,深入了解该模式下的土壤微生态环境的演变。【方法】试验点在湖北省荆州市长江大学农学院基地,设置稻虾共作模式(CR)与常规中稻种植模式(MR),借助荧光定量PCR技... 【目的】研究稻虾共作模式下土壤氨氧化微生物数量、群落多样性及群落结构,深入了解该模式下的土壤微生态环境的演变。【方法】试验点在湖北省荆州市长江大学农学院基地,设置稻虾共作模式(CR)与常规中稻种植模式(MR),借助荧光定量PCR技术与Illumina Miseq高通量测序平台,分析了土壤氨氧化细菌(AOB)与古菌(AOA)丰度、多样性及群落结构。【结果】与MR模式相比,CR模式显著提高了土壤硝态氮、总碳及总氮含量,对土壤p H、碱解氮及土壤碳氮比无显著影响。CR模式土壤AOA与AOB amo A基因拷贝数为3.13×10^5和7.01×10^5 copies/g干土,MR模式土壤AOA、AOB amoA基因拷贝数为1.41×10^5和3.87×10^5 copies/g干土,两个模式土壤AOB的数量均显著高于AOA,CR模式土壤AOA、AOB的数量均显著高于MR模式(P<0.05)。α群落多样性指数表明,相比MR,CR模式显著降低了土壤AOA群落多样性,对AOB群落多样性无显著影响。Venn结果分析,CR模式增加了AOA amoA基因的物种,改变了AOB amoA基因的物种组成,且AOB amoA物种数量下降。在属水平上,norank_c_environmental_samples_p_Thaumarchaeota、unclassified_k_norank_d_Archaea、norank_c_environmental_samples_p_Crenarchaeota、norank_p_environmental_samples_k_norank为AOA的优势类群,相对丰度占AOA amoA基因总序列的99.25%~99.46%,CR模式显著提高了norank_c_environmental_samples_p_Crenarchaeota在AOA群落属水平的相对丰度;unclassified_k_norank_d_Bacteria、norank_f_environmental_samples、norank_o_environmental_samples_c_Betaproteobacteria、unclassified_o_Nitrosomonadales为AOB的优势类群,相对丰度共占97.78%~98.49%,且CR模式显著增加了norank_o_environmental_samples_c_Betaproteobacteria与unclassified_o_Nitrosomonadales在AOB群落属水平的相对丰度。冗余分析(RDA)结果显示,土壤基本理化性质对于土壤AOA、AOB群落结构影响有着相似的趋势,其中对AOA、AOB群落结构影响最大的因子是硝态氮,其 展开更多
关键词 稻虾共作 氨氧化细菌 氨氧化古菌 微生物丰度 群落多样性 高通量测序
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甲醇制烯烃工艺及工业化最新进展 被引量:27
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作者 张世杰 吴秀章 +2 位作者 刘勇 纪贵臣 文尧顺 《现代化工》 CAS CSCD 北大核心 2017年第8期1-6,共6页
综述了目前国内外典型的甲醇制烯烃工艺,包括UOP/Hydro公司的MTO工艺、Exxon Mobile的OTO工艺、大连化物所的DMTO工艺、中石化的SMTO工艺以及神华集团的SHMTO工艺等,对比了其工艺技术特点,详细论述了各自的工业化进程,总结了各自的最新... 综述了目前国内外典型的甲醇制烯烃工艺,包括UOP/Hydro公司的MTO工艺、Exxon Mobile的OTO工艺、大连化物所的DMTO工艺、中石化的SMTO工艺以及神华集团的SHMTO工艺等,对比了其工艺技术特点,详细论述了各自的工业化进程,总结了各自的最新项目进展及运行效果。最后指出,在当前形势下,产品的差异化以及精细化是未来甲醇制烯烃项目保持竞争性的发展方向。 展开更多
关键词 甲醇制烯烃 工艺技术 工业化进程 项目进展
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金融发展是否促进了“一带一路”国家绿色全要素生产率增长? 被引量:22
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作者 王小腾 徐璋勇 刘潭 《经济经纬》 CSSCI 北大核心 2018年第5期17-22,共6页
利用"一带一路"沿线国家的跨国面板数据,基于SBM-DDF模型的龙伯格生产率指数测算绿色全要素生产率,从金融深化、金融结构与金融效率三个维度衡量金融发展,运用动态GMM方法研究金融发展对绿色全要素生产率的影响机制。结果发现... 利用"一带一路"沿线国家的跨国面板数据,基于SBM-DDF模型的龙伯格生产率指数测算绿色全要素生产率,从金融深化、金融结构与金融效率三个维度衡量金融发展,运用动态GMM方法研究金融发展对绿色全要素生产率的影响机制。结果发现:从长期来看,金融深化与金融结构的优化对绿色全要素生产率存在促进作用,而金融效率的过度提升对绿色全要素生产率存在负面效应。针对绿色全要素生产率的分解项而言,在长期,金融深化与金融结构的优化对技术效率存在促进作用,金融结构的优化对技术进步存在促进作用,而金融深化对技术进步存在负面作用。考虑到区域差异性,将样本分为亚洲与欧洲区域,进一步分析发现:欧洲国家金融结构的优化不论长期还是短期对绿色全要素生产率以及技术进步均存在着正向效应,而在亚洲国家中则没有这种效应;在亚洲国家中,金融效率的提升对绿色全要素生产率的影响是负向的,在欧洲国家中,其影响却是正向的。 展开更多
关键词 “一带一路” 金融发展 绿色全要素生产率
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基于改进平滑A*算法的移动机器人路径规划 被引量:19
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作者 付丽霞 任玉洁 +1 位作者 张勇 毛剑琳 《计算机仿真》 北大核心 2020年第8期271-276,共6页
针对传统A*算法用于路径规划时存在路径长、转折角度大、实时性差等问题,本文提出了基于改进平滑A*算法的移动机器人路径规划方法。首先对机器人视觉传感器获取的图像进行处理,得到机器人前方视线范围内障碍物的边缘信息。然后将这些边... 针对传统A*算法用于路径规划时存在路径长、转折角度大、实时性差等问题,本文提出了基于改进平滑A*算法的移动机器人路径规划方法。首先对机器人视觉传感器获取的图像进行处理,得到机器人前方视线范围内障碍物的边缘信息。然后将这些边缘信息中的像素坐标转换为世界坐标,并得到障碍物的实际坐标,从而实现障碍物的识别和定位。机器人行驶过程中,通过融合人工势场的平滑A*算法对检测到的障碍物进行动态避障。实验结果表明,所提出的方法有效避免了传统人工势场法因陷入局部极小值点而导致的路径规划失败问题,并优于D*算法,能够使机器人在移动过程中识别动态障碍物位置,并规划出一条到达目标点的安全无碰撞较优路径。 展开更多
关键词 机器视觉 人工势场法 路径规划 动态避障
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经皮椎体成形术治疗骨质疏松性椎体压缩骨折的临床疗效及术后邻近椎体骨折的危险因素分析 被引量:19
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作者 王强 张骏 +2 位作者 王天 刘万舜 谭章勇 《现代生物医学进展》 CAS 2021年第21期4095-4099,共5页
目的:观察骨质疏松性椎体压缩骨折(OVCFs)患者以经皮椎体成形术(PVP)治疗后的临床疗效,并分析术后邻近椎体骨折的危险因素。方法:选取我院2018年6月~2020年9月期间收治的OVCFs患者180例,给予PVP治疗,观察其治疗效果、骨水泥渗漏情况、... 目的:观察骨质疏松性椎体压缩骨折(OVCFs)患者以经皮椎体成形术(PVP)治疗后的临床疗效,并分析术后邻近椎体骨折的危险因素。方法:选取我院2018年6月~2020年9月期间收治的OVCFs患者180例,给予PVP治疗,观察其治疗效果、骨水泥渗漏情况、术后邻近椎体骨折发生情况,采用单因素及多因素Logistic回归分析术后邻近椎体骨折的危险因素。结果:OVCFs患者术前~术后6个月功能障碍指数(ODI)、疼痛视觉模拟评分(VAS)、活动能力评分(LAS)均呈降低趋势(P<0.05)。随访期间,180例患者中,15例(8.33%)出现了骨水泥渗漏,但均不需要进一步处理。32例(17.78%)出现了术后邻近椎体骨折,148例未出现术后邻近椎体骨折,并以此进行分组。再骨折组、未再骨折组在年龄、骨折病史、骨密度、Cobb角、椎体高度恢复、骨水泥渗漏情况、使用抗骨质疏松药物方面对比有明显差异(P<0.05)。年龄>70岁、骨水泥渗漏、骨密度<-2.5SD、未使用抗骨质疏松药物、Cobb角<15°、椎体高度恢复率>87%均是PVP术后邻近椎体骨折的危险因素(P<0.05)。结论:PVP治疗OVCFs疗效较好,可缓解患者疼痛、减轻功能障碍、改善活动能力,术后邻近椎体骨折的发生受年龄、骨密度、Cobb角等多种因素影响,临床可针对这些因素给予对应的干预措施。 展开更多
关键词 骨质疏松性椎体压缩骨折 邻近椎体骨折 疗效 经皮椎体成形术 危险因素
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二代测序技术检测650例非小细胞肺癌驱动基因突变 被引量:16
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作者 赵冉 伍潇怡 +4 位作者 陈颖玮 何章勇 罗鹏 黄维纲 王雪亮 《临床与实验病理学杂志》 CAS CSCD 北大核心 2022年第2期152-156,共5页
目的探讨驱动基因在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的突变情况。方法采用二代测序(next-generation sequencing,NGS)靶向检测,分析650例NSCLC组织中ALK、BCL2L11、BRAF、EGFR、ERBB2、FGFR、KRAS、MAP2K1、MET、NRAS... 目的探讨驱动基因在非小细胞肺癌(non-small cell lung cancer,NSCLC)中的突变情况。方法采用二代测序(next-generation sequencing,NGS)靶向检测,分析650例NSCLC组织中ALK、BCL2L11、BRAF、EGFR、ERBB2、FGFR、KRAS、MAP2K1、MET、NRAS、NTRK、PIK3CA、RET、TP53、ROS1共15种基因的突变情况。结果NSCLC中至少发生1种基因突变频率为61.23%。67.65%突变位点位于EGFR基因;携带EGFR突变患者有313例(48.15%),其中56例(17.89%)合并其他基因突变,包括48例EGFR合并另1种基因突变,7例EGFR合并其他2种基因共突变以及1例EGFR合并其他3种基因共突变。除exon 19del、exon 20ins、T790M和L858R外,还发现其他24种非常见EGFR突变;除EML4-ALK融合外,还发现3种ALK基因其他不同位点突变。NSCLC中女性、腺癌患者发生突变的频率更高(P<0.05)。结论应用NGS技术可揭示NSCLC各驱动基因变异更多的独特特征,为NSCLC药物开发和靶向治疗提供参考。 展开更多
关键词 肺肿瘤 非小细胞肺癌 二代测序 基因突变 EGFR
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基于3种标准的社区老年患者潜在不适当用药评估 被引量:16
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作者 陈张勇 刘利刚 +4 位作者 吐达洪 张京慧 孙路路 赵志刚 栗芳 《中国新药与临床杂志》 CAS CSCD 北大核心 2018年第12期700-706,共7页
目的调查本院医联体社区卫生服务站老年患者潜在不适当用药(PIM)情况,并分析3种标准适用性。方法采用问卷调查形式现场调查本院医联体社区卫生服务站65岁以上老年患者用药情况,分别以2015版Beers标准、 2014版STOPP准则和《中国老年人... 目的调查本院医联体社区卫生服务站老年患者潜在不适当用药(PIM)情况,并分析3种标准适用性。方法采用问卷调查形式现场调查本院医联体社区卫生服务站65岁以上老年患者用药情况,分别以2015版Beers标准、 2014版STOPP准则和《中国老年人潜在不适当用药目录》为依据,对社区老年患者用药情况进行评估分析。结果调查共收集患者795例,年龄为(77.7±7.3)岁,患病(4.6±2.1)种,用药品种(5.2±3.0)种。依据Beers标准, 202例(25.4%)患者存在共261项PIM;依据STOPP准则, 147例(18.5%)患者存在共202项PIM;依据《中国老年人潜在不适当用药目录》, 230例(28.9%)患者存在共275项PIM。Beers标准提示存在PIM而STOPP准则和《中国老年人潜在不适当用药目录》未提示PIM的患者数量均为83例。《中国潜在不适当用药目录》提示存在PIM而Beers标准和STOPP准则未提示PIM的患者数量分别为111例和107例。STOPP准则提示存在PIM而Beers标准和《中国老年人潜在不适当用药目录》未提示PIM的患者数量分别为28例和24例。结论本院医联体社区老年患者存在PIM情况较为严重, 3种标准在评估和预防中国社区老年患者PIM中均有重要参考意义,联合使用Beers标准和《中国老年人潜在不适当用药目录》更为敏感。 展开更多
关键词 老年人 Beers标准 STOPP准则 中国老年人潜在不适当用药目录 老年人保健服务
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保险能改善对农户的信贷配给吗?——来自822户农户调查的经验证据 被引量:15
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作者 左斐 徐璋勇 罗添元 《云南财经大学学报》 CSSCI 北大核心 2019年第8期63-75,共13页
针对保险能否支持农户融资的问题,基于2014年陕、苏二省822户农户的调查数据,采用四元Probit模型,在有效分离信贷、保险供需行为的前提下,对保险之于农户信贷供给的影响进行实证检验。结果显示,总体上保险的存在显著提高了农户获取正规... 针对保险能否支持农户融资的问题,基于2014年陕、苏二省822户农户的调查数据,采用四元Probit模型,在有效分离信贷、保险供需行为的前提下,对保险之于农户信贷供给的影响进行实证检验。结果显示,总体上保险的存在显著提高了农户获取正规信贷的能力,但与信贷损失挂钩的农作物保险相比其他类别的商业保险更能发挥作用;同时,陕西样本地区相比江苏样本地区保险对信贷的支持作用更加明显,而这一差异来源于陕西样本地区政策性的银保互联支持。研究为信贷保险互联的制度安排提供了进一步经验支持。着眼于缓解农户信贷配给,应当进一步支持构建多样化的信贷保险关联机制。 展开更多
关键词 信贷可得性 信息不对称 信贷配给 四元Probit
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