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Synthesis of Vanadium Carbide Nanopowders via Mechanical Alloying and Microwave Heating Methods

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Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 332-336页

作者：杨宝震 zheng Hongjuan 赵志伟 zheng juan CHEN Feixiao School of Material Science and Engineering Henan University of Technology

A simple and fast method of preparation of vanadium carbide(V_8 C_7) nanopowders using mechanical alloying assisted microwave heating method was demonstrated. The micron-sized V_2O_5 and nano-sized carbon black were used as starting materials. The as-prepared powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), thermogravimetric and differential scanning calorimetry(TG-DSC), transmission electron microscopy(TEM), and X-ray photoelectron spectroscopy(XPS) techniques. The experimental results show that the V_8C_7 powders can be obtained by microwave heating at 1 100 ℃ for 1 h(34 wt% C). The synthesized powders show good dispersion and are mainly composed of spherical or near-spherical particles with a mean diameter of about 30 nm. The XPS spectra show that the surface of the specimen mainly consists of V, C, and O three species elements.

关键词： vanadium carbide mechanical alloying microwave heating microstructure nanopowders

Therapeutic effect of Cistanche deserticola on defecation in senile constipation rat model through stem cell factor/C-kit signaling pathway

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World Journal of Gastroenterology 2021年第32期27卷 5392-5403页

作者： Xia Zhang Fa-juan zheng Zhen Zhang Department of Science and Education Chongqing Hospital of Traditional Chinese MedicineChongqing 400021China Department of Anorectal Chongqing Hospital of Traditional Chinese MedicineChongqing 400021China

BACKGROUND Constipation is one of the chronic gastrointestinal functional *** seriously affects the quality of *** deserticola(***)can treat constipation obviously,but its mechanism has not been *** supposed that mechanism of it improved the intestinal motility by stimulating interstitial Cajal cells(ICC).Activation of the C-kit receptor on the surface of ICC is closely related to ICC function,and the stem cell factor(SCF)/C-kit signaling pathways plays an important role on *** investigate the mechanism of how *** treats constipation,this study aimed to establish a constipation model in rats and explore the role of SCF/C-kit signaling pathway in the *** To explore the SCF/C-kit signaling pathways in the role of *** for treatment of constipation by a constipation rat *** Forty-eight 8-mo-old Sprague–Dawley rats were divided into 4 groups by random weight method:Normal group(n=12),model group(n=12),*** group(n=12)and blocker group(n=12).The normal group received normal saline by gavage;the model group received loperamide by gavage;the blocker group received loperamide and *** by gavage,and STI571 was injected by *** treatment,the weight,fecal granules and fecal quality were recorded every 10 *** day 20 after model induction,the colon tissues of each group were *** and eosin staining was used to observe pathological *** levels of SCF,C-kit and Aquaporin genes were detected by immunohistochemistry,western blotting,and real-time-quantitative polymerase chain *** colonic epithelial mitochondria and goblet cells were observed by transmission electron *** Compared with the normal group,as treatment progressed,the weight of rats in the model and blocker groups decreased significantly,the stool weight decreased,and the stool quality was dry(P<0.05).*** reversed the decrease in body weight and

关键词： Cistanche deserticola Senile constipation Stem cell factors C-kit

Improved stability and oral bioavailability of Ganneng dropping pills following transforming lignans of herpeto- spermum caudigerum into nanosuspensions

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Chinese Journal of Natural Medicines 2018年第1期16卷 70-80页

作者： LI juan-juan CHENG Ling SHEN Gang QIU Ling SHEN Cheng-Ying zheng juan XU Rong YUAN Hai-Long Department of Pharmacy Air Force General Hospital of PLA Beijing 100142 China Department of Pharmacy Guangyuan Central Hospital Guanyuan 628000 China Department of Pharmacy Shuangliu District Maternal and Child Health Hospital Chengdu 610075 China Chengdu Institute of Chinese Herbal Medicine Chengdu 610045 China

The present study was designed to improve storage stability and oral bioavailability of Ganneng dropping pills(GNDP) by transforming lignans of Herpetospermum caudigerum(HL) composed of herpetrione(HPE) and herpetin(HPN) into nanosuspension(HL-NS), the main active ingredient of GNDP, HL-NS was prepared by high pressure homogenization and lyophilized to transform into solid nanoparticles(HL nanoparticles), and then the formulated HL nanoparticles were perfused into matrix to obtain NS-GNDP by melting method. For a period of 3 months, the content uniformity, storage stability and pharmacokinetics test in vivo of NS-GNDP were evaluated and compared with regular GNDP at room temperature. The results demonstrated that uniformity of dosage units of NS-GNDP was acceptable according to the criteria of Chinese Pharmacopoeia 2015 J. Physical stability of NS-GNDP was investigated systemically using photon correlation spectroscopy(PCS), zeta potential measurement, and scanning electron microscopy(SEM). There was a slight increase in particles and PI of HL-NS re-dispersed from NS-GNDP after storage for 3 months, compared with new formulated NS-GNDP, which indicated a good redispersibility of the NS-GNDP containing HL-NS after storage. Besides, chemical stability of NS-GNDP was studied and the results revealed that HPE and HPN degradation was less when compared with that of GNDP, providing more than 99% of drug residue after storage for 3 months. In the dissolution test in vitro, NS-GNDP remarkably exhibited an increased dissolution velocity compared with GNDP and no distinct dissolution difference existed within 3 months. The pharmacokinetic study showed that HPE and HPN in NS-GNDP exhibited a significant increase in AUC0–t, Cmax and decrease in Tmax when compared with regular GNDP. These results indicated that NS-GNDP possessed superiority with improved storage stability and increased dissolution rate and oral bioavailability.

关键词： Ganneng dropping pills Lignans Herpetospermum caudigerum Nanosuspensions Stability Oral bioavailability

Synthesis of vanadium and chromium carbides(V_8C_7–Cr_3C_2) nanocomposite via an in situ precursor method

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Rare Metals 2015年第7期34卷 498-504页

作者： Zhi-Wei Zhao Wen-Meng Hu Hong-juan zheng Fei-Xiao Chen College of Materials Science and Engineering Henan University of Technology

In situ synthesis method was used to prepare V8C7–*** vanadate, ammonium dichromate and nanometer carbon black were used as raw *** products were characterized by X-ray diffractometry(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), thermogravimetric and differential scanning calorimetry(TGDSC) and X-ray photoelectron spectroscopy(XPS) *** results show that V8C7–Cr3C2nanocomposite with an average crystallite size of 25.4 nm can be synthesized at 1200 °C for 1 *** synthesis temperature required by the method is at least 200 °C lower than that required by the conventional approaches for preparing vanadium and chromium *** powders show good dispersion and are mainly composed of spherical or nearly spherical particles with a mean diameter of about 30 *** weight loss ratio of the precursor throughout the reaction process reaches 58 wt%.Three exothermic peaks and four endothermic peaks occur during the *** surface of the specimen is mainly composed of V, Cr, C and O elements.

关键词： Nanocomposite Carbides Precursor In situ synthesis

Researches of soft-sediment deformation structures and seismites in China—A brief review

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Journal of Palaeogeography 2016年第4期5卷 311-317页

作者： Zeng-Zhao Feng Zhi-Dong Bao Xiu-juan zheng Yuan Wang China University of Petroleum(Beijing)

During the past 30 years （1987-2016）, a great progress has been made in researches of soft-sediment deformation structures （SSDS）, seismites and pataeoearthquakes in China. However, the research thought of this academic fietd is not open enough. It is atmost with one viewpoint or one voice, i.e., atmost art the papers pubtished in journals of China considered the layers with SSDS as seismites. On the other hand, the authors are very glad to learn that the professors and students of China University of Petroleum （East China） have proposed different academic viewpoints on the origin of SSDS in Lingshan Istand, Qingdao, Shandong Province, China. It is a very active academic atmosphere. The authors＇ ideas are as follows：（1） The SSDS are sedimentary structures with multi-origin. The term ＂SSDS＂ is a good sedimentary and geological term and shoutd be utilized continuat[y. （2） The term ＂seismites＂ is a term which is definitety assigned to the layers with SSDS induced by earthquakes. It is one type of the tayers with SSDS. It is not equal to SSDS. （3） Some geotogists suggested obsoleting the term ＂seismites＂. These suggestions are rational However, since the term ＂seismites＂ has been utilized for a long time in China and worldwide, to obsolete this term should be discussed and agreement should be acquired from numerous geologists in China and worldwide. It may be suitable that let the geological practice decide whether to obsolete it or not. （4） Hopefully, further progress will be made in the researches of SSDS.

关键词： Soft-sediment deformation structures (SSDS) Multi-origin Seismites Pataeoearthquake Ling-shan Island China

There was no “Great Bank of Guizhou” in the Early Triassic in Guizhou Province, South China

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Journal of Palaeogeography 2015年第1期4卷 99-108页

作者： Zeng-Zhao Feng Zhi-Dong Bao Xiu-juan zheng Yuan Wang China University of Petroleum (Beijing)

In the 1990s, some geologists named the Early Triassic isolated carbonate platform in the Luodian area of southern Guizhou Province in South China as the ＂Great Bank of Guizhou＂. During the past twenty years, this term ＂Great Bank of Guizhou＂ was used in more than 300 articles in foreign countries. In the 1990s, the authors have studied the lithofacies palaeogeography of the Early and Middle Triassic in South China. In June 2014, we went to the Luodian area and studied the Early Triassic Bianyang section again. According to the geological data we acquired, in the Early Triassic of the Luodian area of southern Guizhou Province, there was only an isolated ＂Luodian Carbonate Platform＂, while no bank existed, not to mention the ＂Great Bank of Guizhou＂. It is worth further discussion.

关键词： Early Triassic Luolou Formation Ziyun Formation Great Bank of GuizhouLuodian Carbonate Platform Bianyang section South China

Uniaxial Time-Dependent Ratcheting of SS304 Stainless Steel at High Temperatures

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Journal of Iron and Steel Research International 2007年第1期14卷 53-59页

作者： KANG Guo-zheng ZHANG juan SUN Ya-fang KAN Qian-hua Department of Applied Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 Sichuan China

The uniaxial time-dependent strain cyclic behaviors and ratcheting of SS304 stainless steel were studied at high temperatures （350 ℃ and 700 ℃）. The effects of straining and stressing rates, holding time at the peak and/or valley of each cycle in addition to ambient temperature on the cyclic softening/hardening behavior and ratcheting of the material were discussed. It can be seen from experimental results that the material presents remarkable time dependence at 700 ℃, and the ratcheting strain depends greatly on the stressing rate, holding time and ambient temperature. Some significant conclusions are obtained, which are useful to build a constitutive model describiog the time-dependent cyclic deformation of the material.

关键词： SS304 stainless steel time dependence ratcheting high temperature

Comparison of surgical effect and postoperative patient experience between laparoendoscopic single-site and conventional laparoscopic varicocelectomy, a *** and meta-analysis

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Asian Journal of Andrology 2017年第2期19卷 248-255页

作者： zheng Zhang Shu-juan zheng Wen Yu You-Feng Han Hai Chen Yun Chen Yu-Tian Dai Department of Andrology Affiliated Drum Tower Hospital School of Medicine Nanjing University Nanjing 210008 China

The present meta-analysis was conducted to compare the clinical effect and patient experience of laparoendoscopic single-site varicocelectomy （LESSV） and conventional laparoscopic varicocelectomy. The candidate studies were included after literature search of database Cochrane Library, PubMed, EMBASE, and MEDLINE. Related information on essential data and outcome measures was extracted from the eligible studies by two independent authors, and a meta-analysis was conducted using STATA 12.0 software. Subgroup analyses were conducted by study design （RCT and non-RCT）. The odds ratio （OR） or standardized mean difference （SMD） and their 95% confidence intervals （95% CIs） were used to estimate the outcome measures. Seven articles were included in our meta-analysis. The results indicated that patient who had undergone LESSV had a shorter duration of back to work （overall： SMD = -1.454, 95% Ch -2.502m0.405, P= 0.007; non-RCT： SMD = -2.906, 95% Ch -3.796-2.017, P= 0.000; and RCT： SMD = -0.841, 95% Ch -1.393-0.289, P = 0.003） and less pain experience at 3 h or 6 h （SMD = -0.447, 95% Ch -0.754-0.139, P = 0.004）, day 1 （SMD = -0.477, 95% Ch -0.905-0.05, P = 0.029）, and day 2 （SMD = -0.612, 95% Ch -1.099-0.125, P= 0.014） postoperatively based on RCT studies. However, the meta-analyses based on operation time, clinical effect （improvement of semen quality and scrotal pain relief）, and complications （hydrocele and recurrence） yielded nonsignificant results. In conclusion, LESSV had a rapid recovery and less pain experience over conventional laparoscopic varicocelectomy. However, there was no statistically significant difference between the two varicocelectomy techniques in terms of the clinical effect and the incidence of hydrocele and varicocele recurrence. More high-quality studies are warranted for a comprehensive conclusion.

关键词： complications conventional laparoscopic varicocelectomy laparoendoscopic single-site varicocelectomy meta-analysis pain score semen quality

Optimal timing of invasive intervention for high-risk non-ST-segment-elevation myocardial infarction patients

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Journal of Geriatric Cardiology 2024年第8期21卷 807-815页

作者： juan-juan zheng Yue-Qiao SI Tian-Yang XIA Bing-Jun LU Chun-Yu ZENG Wei-Eric WANG Department of Geriatrics Southwest HospitalThird Military Medical UniversityChongqingChina Department of Cardiology Daping HospitalThird Military Medical UniversityChongqingChina

OBJECTIVE To compare the immediate,early,and delayed percutaneous coronary intervention(PCI)strategies in non-ST-segment-elevation myocardial infarction(NSTEMI)patients with *** Medical records of patients treated at the Daping Hospital,Third Military Medical University,Chongqing,China between 2011 and 2021 were retrospectively *** patients with complete available information were *** patients assigned into three groups based on the timing of PCI including immediate(<2 h),early(2–24 h)and delayed(≥24 h)*** Cox hazards regression and simpler nonlinear models were *** A total of 657 patients were included in the *** median follow-up length was 3.29(interquartile range:1.45–4.85)*** PCI strategy improved the major adverse cardiac event(MACE)outcome compared to the immediate or delayed PCI *** PCI,diabetes mellitus,and left main or/and left anterior descending or/and left circumflex stenosis or/and right coronary artery≥99%were predictors for MACE *** optimal timing range for PCI to reduce MACE risk is 3–14 h *** high-risk NSTEMI patients,early PCI reduced primary clinical outcomes compared to immediate or delayed PCI,and the optimal timing range was 3–14 h *** PCI was superior for NSTEMI with chronic kidney *** Delayed invasive strategy was helpful to reduce the incidence of MACE for high-risk NSTEMI with chronic kidney *** immediate PCI strategy might increase the rate of MACE.

关键词： patients infarction Chongqing