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活结法硅胶管逆行植入鼻泪管治疗下泪道阻塞 被引量:5
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作者 刘东光 《眼科新进展》 CAS 北大核心 1989年第3期47-48,共2页
我院自1987年用活结法行硅胶管逆行植入鼻泪管治疗下泪道阻塞23例,经4月~1年观察,疗效与袁氏鼻泪管逆行放置义管相似,但本术式更简便,报告如下.
关键词 泪道阻塞 鼻泪管 活结法 硅胶管
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巧用活结系于单侧鼻导管留置胃管固定法的效果观察 被引量:2
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作者 邓金燕 左美玉 +1 位作者 华锋凯 廖昌燕 《右江医学》 2018年第2期247-248,共2页
对于不能经口进食或胃肠减压的患者,插胃管是一个重要治疗手段。插管后的留置与固定是临床护理的工作重点。有效固定胃管不仅便于观察胃液性质和量,还可进行有效减压、引流,减轻吻合口张力,促进伤口愈合,减少术后并发症的发生[1]... 对于不能经口进食或胃肠减压的患者,插胃管是一个重要治疗手段。插管后的留置与固定是临床护理的工作重点。有效固定胃管不仅便于观察胃液性质和量,还可进行有效减压、引流,减轻吻合口张力,促进伤口愈合,减少术后并发症的发生[1]。若不能妥善固定,易造成胃管移位、脱出,引起呛咳、误吸甚至威胁患者生命[2]。因胃管固定不牢而造成意外拔管的发生率为9.8%~45.2%[3],不仅增加患者术后并发症风险、延长住院天数、增加住院费用,还增加了护理工作量[4]。笔者自创一种胃管固定方法,并与传统胃管固定方法作对照,现在总结如下。 展开更多
关键词 胃管留置 胃管固定 活结固定 传统固定
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可拆除双活结无张力荷包缝合法在耻骨上前列腺切除术中的应用 被引量:1
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作者 程世平 贾全安 +4 位作者 任光学 高志强 蔡宏俊 周德清 王乐群 《临床泌尿外科杂志》 2000年第6期275-276,共2页
关键词 前列腺切除术 活结无张力荷包缝合 术式
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Effect of cetyltrimethylammonium bromide on morphology and porous structure of mesoporous hydroxyapatite 被引量:4
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作者 王晶 黄苏萍 +2 位作者 胡堃 周科朝 孙虹 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期483-489,共7页
The mesoporous hydroxyapatite (HA) was synthesized by hydrothermal method utilizing cationic surfactant cetyltrimethylammonium bromide (CTAB) as template. The crystalline phase, morphology and porous structure wer... The mesoporous hydroxyapatite (HA) was synthesized by hydrothermal method utilizing cationic surfactant cetyltrimethylammonium bromide (CTAB) as template. The crystalline phase, morphology and porous structure were characterized respectively by different detecting techniques. The results reveal that the particles are highly crystalline hydroxyapatite phase. The surfactant has little influence on the morphology of the crystals, but affects the porous structure obviously. The sample without CTAB has a low surface area not exceeding 33 m^2/g, and no distinct pores can be observed by TEM. While the samples obtained with the surfactant get better parameters. Numerous open-ended pores centered at 2-7 nm spread unequally on the surface of the hydroxyapatite nanorods. The N2 adsorption-desorption experiments show type IV isotherms with distinct hysteresis loops, illustrating the presence of mesoporous structure. When the mole ratio of CTAB to HA is 1:2, the sample has the largest surface area of 97.1 m^2/g and pore volume of 0.466 cm^3/g. 展开更多
关键词 HYDROXYAPATITE cetyltrimethylammonium bromide cationic surfactant soft-template mesoporous structure
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Rational construction of thermally stable single atom catalysts:From atomic structure to practical applications 被引量:4
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作者 Hongwei Lv Wenxin Guo +2 位作者 Min Chen Huang Zhou Yuen Wu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2022年第1期71-91,共21页
As a new frontier in catalysis field,single-atom catalysts(SACs)hold unique electronic structure and high atom utilization,which have displayed unprecedented activity and selectivity toward a wide range of catalytic r... As a new frontier in catalysis field,single-atom catalysts(SACs)hold unique electronic structure and high atom utilization,which have displayed unprecedented activity and selectivity toward a wide range of catalytic reactions.However,many reported SACs are susceptible to Ostwald ripening process in high temperature environment or long-term catalytic application,which will cause sintering and deactivation.This is due to the weak interaction between the metal atom and supports.The regeneration and recycling of deactivated catalysts will greatly increase the time and economic cost of industrial production.Therefore,it is necessary to develop SACs with excellent thermal stability to meet the industrial demands.Here,we discuss the fundamental comprehension of the stability of thermally stable SACs obtained from different synthesis methods.The influences of the speciation of metal centers and coordination environments on thermal stability are summarized.The importance of using novel in situ and operando characterizations to reveal dynamic structural evolution under synthesis and reaction conditions and to identify active sites of thermally stable SACs is highlighted.The mechanistic understanding of the unique role of thermally stable SACs in thermocatalytic application is also discussed.At last,a brief perspective on the remaining challenges and future directions of thermally stable SACs is presented. 展开更多
关键词 Thermal stability Single-atom catalyst Sintering and deactivation Synthesis method Thermocatalytic application
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Er^(3+)-activated silica inverse opals synthesized by the solgel method 被引量:2
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作者 A. Chiappini C.Armellini +11 位作者 A. Chiasera Y. Jestin M. Ferrari M. Mattarelli M. Montagna E. Moser C. Tosello L. Zampedri G. Nunzi Conti S. Pelli R. M. Almeida G. C. Righini 《Optoelectronics Letters》 EI 2007年第3期184-187,共4页
We present the details of the sol-gel processing used to realize inverse silica opal,where the silica was activated with 0.3 mol% of Er3+ ions. The template(direct opal) was obtained assembling polystyrene spheres of ... We present the details of the sol-gel processing used to realize inverse silica opal,where the silica was activated with 0.3 mol% of Er3+ ions. The template(direct opal) was obtained assembling polystyrene spheres of the dimensions of 260 nm by means of a vertical deposition technique. The Er3+-activated silica inverse opal was obtained infiltrating,into the void of the template,the silica sol doped with Er3+ ions and subsequently removing the polystyrene spheres by means of calcinations. Scanning electron microscope showed that the inverse opals possess a fcc structure with a air hollows of about 210 nm and a photonic band gap,in the visible range,was observed from reflectance measurements. Spectroscopic properties of Er3+-activated silica inverse opal were investigated by luminescence spectroscopy,where,upon excitation at 514.5 nm,an emission of 4I13/2 → 4I15/2 of Er3+ ions transition with a 21 nm bandwidth was observed. Moreover the 4I13/2 level decay curve presents a single-exponential profile,with a measured lifetime of 18 ms,corresponding a high quantum efficiency of the system. 展开更多
关键词 铒掺杂 活性硅 反opal结构 溶胶-凝胶 合成
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Preparation, characterization and catalytic performance of single-atom catalysts 被引量:20
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作者 Liqiong Wang Liang Huang +3 位作者 Feng Liang Simin Liu Yuhua Wang Haijun Zhang 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第9期1528-1539,共12页
Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation ... Supported and colloidal single‐atom catalysts(SACs),which possess excellent catalytic properties,are particularly important in both fundamental studies and practical applications.The progress made in the preparation methods,characterization,catalytic performances and mechanisms of SACs anchored to metal oxides,two‐dimensional materials and the surface of metal nanoclusters(NCs)are reviewed.The different techniques for SAC fabrication,including conventional solution methods based on co‐precipitation,incipient wetness co‐impregnation,and the chemical vapor deposition method,as well as the newer atom layer deposition(ALD)and galvanic replacement methods,are summarized.The main results from experimental and theoretical studies of various catalytic reactions over SACs,including oxidation reactions,hydrogenation,water gas shift,photocatalytic H2evolution and electrochemical reactions,are also discussed.Moreover,the electronic properties of the single atoms and their interactions with the supports are described to assist in understanding the origin of the high catalytic activity and selectivity of SACs.Finally,possible future research directions of SACs and their applications are proposed. 展开更多
关键词 Single atom catalyst Preparation method Catalytic activity CHARACTERIZATION Electronic properties
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Is sentinel lymph node biopsy necessary for the patients diagnosed with breast ductal carcinoma in situ using core needle biopsy or vacuum-assisted biopsy as the initial diagnostic method? 被引量:4
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作者 Xiaoyi Zhang Rui Wang +1 位作者 Zhiyong Wu Xueqing Jiang 《The Chinese-German Journal of Clinical Oncology》 CAS 2014年第11期509-514,共6页
Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ (DCIS). The purpose of this study was to investigate whether sentine... Axillary lymph node status is one of the most important prognostic indicator of survival for breast cancer, especially in ductal carcinoma in situ (DCIS). The purpose of this study was to investigate whether sentinel lymph node biopsy (SLNB) should be performed in patients with an initial diagnosis of DCIS. Methods: A retrospective study was performed of 124 patients with an initial diagnosis of DCIS between March 2000 and June 2014. The patients were treated with either SLNB or axillary node dissection during the surgery, and we compared the clinicopathologic characteristics, image features, and immunohistochemical results. Results: Eighty-two patients (66.1%) had pure DCIS and 25 (20.2%) had DCIS with microinvasion (DCISM), 17 (13.7%) updated to invasive breast cancer (IBC). 115 patients (92.7%) underwent SLNB, among them, 70 patients (56.5%) underwent axillary node dissection. 3 of 115 patients (2.6%) had a positive sentinel lymph node, only 1 (1.4%) of 70 patients had axillary lymph node metastasis, in 84 patients (66.7%) who were diagnosed DCIS by core needle biopsy (CNB) and vacuum-assisted biopsy (VAB). 26 patients (31.0%) were upstaged into IBC or DCISM in the final histological diagnosis. The statistically significant factors predictive of underestimation were large tumor size, microcalcifications, comedo necrosis, positive Her-2 status, negative estrogen receptor status. Conclusion: The metastasis of sentinel lymph nodes in pure DCIS is very low, but the underestimation of invasive carcinoma in patients with an initial diagnosis of DCIS is an usual incident, especially in the cases when DCIS is diagnosed by CNB or VAB. Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated with large tumor sizes, microcalcifications, comedo necrosis, positive Her-2 status, negative ER status are more likely to be DCISM and IBC in final diagnosis. SLNB should be performed in this part of patients. 展开更多
关键词 ductal carcinoma in situ (DCIS) breast cancer sentinel lymph node biopsy (SLNB) core needle biopsy (CNB) vacuum-assisted biopsy (VAB)
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Predicting intrinsic disorder in proteins: an overview 被引量:11
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作者 Bo He Kejun Wang +3 位作者 Yunlong Liu Bin Xue Vladimir N Uversky A Keith Dunker 《Cell Research》 SCIE CAS CSCD 2009年第8期929-949,共21页
The discovery of intrinsically disordered proteins (IDP) (i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures) came as an unexpected surprise, as the existence of suc... The discovery of intrinsically disordered proteins (IDP) (i.e., biologically active proteins that do not possess stable secondary and/or tertiary structures) came as an unexpected surprise, as the existence of such proteins is in contradiction to the traditional "sequence →structure →function" paradigm. Accurate prediction of a protein's predisposition to be intrinsically disordered is a necessary prerequisite for the further understanding of principles and mechanisms of protein folding and function, and is a key for the elaboration of a new structural and functional hierarchy of proteins. Therefore, prediction of IDPs has attracted the attention of many researchers, and a number of prediction tools have been developed. Predictions of disorder, in turn, are playing major roles in directing laboratory experiments that are leading to the discovery of ever more disordered proteins, and thereby leading to a positive feedback loop in the investigation of these proteins. In this review of algorithms for intrinsic disorder prediction, the basic concepts of various prediction methods for IDPs are summarized, the strengths and shortcomings of many of the methods are analyzed, and the difficulties and directions of future development of IDP prediction techniques are discussed. 展开更多
关键词 PROTEIN intrinsic disorder prediction method
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Design and Synthesis of Novel Fluorine-containing Acrylates 被引量:1
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作者 Yan Chao WU Chao WU Xiao Mao ZOU Fang Zhong HU Hua Zheng YANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第10期1293-1296,共4页
A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These ... A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed. 展开更多
关键词 Fluorine-containing compound ACRYLATES synthesis.
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Colorectal cancer lymph node staining by activated carbon nanoparticles suspension in vivo or methylene blue in vitro 被引量:41
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作者 Hong-Ke Cai Hai-Fei He Wei Tian Mei-Qi Zhou Yue Hu Yong-Chuan Deng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第42期6148-6154,共7页
AIM:To investigate whether activated carbon nanoparticles suspension(ACNS) or methylene blue(MB) can increase the detected number of lymph nodes in colorectal cancer.METHODS:Sixty-seven of 72 colorectal cancer patient... AIM:To investigate whether activated carbon nanoparticles suspension(ACNS) or methylene blue(MB) can increase the detected number of lymph nodes in colorectal cancer.METHODS:Sixty-seven of 72 colorectal cancer patients treated at our hospital fulfilled the inclusion criteria of the study which was conducted from December 2010 to February 2012.Seven patients refused to participate.Eventually,60 patients were included,and randomly assigned to three groups(20 in each group):ACNS group(group A),MB group(group B) and non-stained conventional surgical group(group C).In group A,patients received subserosal injection of 1 mL ACNS in a 4-quadrant region around the mass.In group B,the main artery of specimen was identified and isolated after the specimen was removed,and 2 mL MB was slowly injected into the isolated,stretched and fixed vessel.In group C,no ACNS and MB were injected.All the mesentery lymph nodes were isolated and removed systematically by visually inspecting and palpating the adipose tissue.RESULTS:No difference was observed among the three groups in age,gender,tumor location,tumor diameter,T-stage,degree of differentiation,postoperative complications and peritoneal drainage retention time.The total number of detected lymph nodes was 535,476 and 223 in the three groups,respectively.The mean number of detected lymph nodes per patient was significantly higher in group A than in group C(26.8 ± 8.4 vs 12.2 ± 3.2,P < 0.001).Similarly,there were significantly more lymph nodes detected in group B than in group C(23.8 ± 6.9 vs 12.2 ± 3.2,P < 0.001).However,there was no significant difference between group A and group B.There were 50,46 and 32 metastatic lymph nodes dissected in 13 patients of group A,10 patients of group B and 11 patients of group C,without significant differences among the three groups.Eleven of the 60 patients had insufficient number of detected lymph nodes(< 12).Only one patient with T 4a rectal cancer had 10 lymph nodes detected in group B,the other 10 patients were all from group C.Based on the different diameter categories,the number of detected lymph nodes in groups A and B was significantly higher than in group C.However,there was no statistically significant difference between group A and group B.The metastatic lymph nodes were not significant different among the three groups.Similarly,tumor location,T stage and tumor differentiation did not affect the staining results.Body mass index was a minor influencing factor in the two different staining methods.The stained lymph nodes can easily be identified from the mesenteric adipose tissues,and the staining time for lymph nodes was not significantly different compared with unstained group.None of the patients in groups A and B had drug-related complications.CONCLUSION:Both activated carbon nanoparticles suspension in vivo and methylene blue in vitro can be used as tracers to increase the detected number of lymph nodes in colorectal cancer. 展开更多
关键词 NANOTECHNOLOGY Activated carbon nanoparticles suspension Methylene blue Lymph nodes Colorectal cancer
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Decreasing Pin1 suppresses telomerase activity by NF-κB in HCT116 cells colorectal carcinoma
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作者 Jianwen Sun Lijun Fan +2 位作者 Meining Li Yuehong Zhang Niuliang Cheng 《The Chinese-German Journal of Clinical Oncology》 CAS 2013年第4期181-187,共7页
Objective: The aim of our study was to investigate the effect of Pin 1 on the telomerase activity in human colorectal carcinoma HCT116 cells. Methods: Firstly, we transfected plasmid pGenesil-l-Pinl (p-shRNA) usin... Objective: The aim of our study was to investigate the effect of Pin 1 on the telomerase activity in human colorectal carcinoma HCT116 cells. Methods: Firstly, we transfected plasmid pGenesil-l-Pinl (p-shRNA) using liposome (Lipofectamine 2000) into colorectal cancer HCT-116 cells to down-regulate the expression of Pin1. To detect the apoptotic rate of HCT116 cells was by cytometry (FCM). The expression of Pin1 and hTERT at RNA levels in human colorectal cancer HCT116 cells were determined by RT-PCR. To evaluate the activity of telomerase was by TRAP-silver staining. The subcellular localization and accumulative level of p-NF-κB/p65 protein at the nuclear was detected by Immunofluorescence and Western blotting. The DNA-binding activity of NF-κB/p65 was detected by electrophoretic mobility shift assay (EMSA). Results: Using liposome into colorectal cancer HCT-116 cells, and down-regulate the expression of Pin1 (0.392 ± 0.072-fold; P = 0.001), and the apoptotic rate was increased (11.40% ± 1.54%; P 〈 0.05). Compared with transfected p-CON cell group, in transfected p-shRNA cell group, the transcription of hTERT was lower (0.171 ±0.060-fold; P = 0.001) by quantitative real-time RT-PCR, and the results of TRAP-silver staining analysis suggested that the telomerase activity was significantly declined (0.384 ± 0.015-fold; P 〈 0.05). Furthermore, it was demonstrated by Immunofluorescence that p-NF-κB/p65 had a nuclear localization, and the level of p-NF-κB/p65 protein at the nuclear was reduced with silencing the expression of Pin1 by Western blotting. Using EMSA, it was suggested that NF-κB/p65 was able to bind to hTERT promoter, and the direct interaction was declined with silencing the expression of Pin1. Conclusion: Taken together, silencing Pin1 may suppress activity of telomerase and the expression of hTERT by inhibiting NF-κB/p65 activity and reducing the combination of NF-κB/p65 and hTERT gene promoter. 展开更多
关键词 colonic cancer PIN1 HTERT NF-ΚB
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给蛇口戴个帽
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作者 王宁 《中国钓鱼》 2004年第12期23-23,共1页
在手竿主线与竿梢蛇口线的连接上,不少钓友采用“活结法”。即在主线一端10厘米处回折后打上下两个结,组装时将食指、中指插入两结间后翻转勾出一活扣,然后将它套在事先已在竿梢蛇口线末端打好的一死结后方拉紧即可。此种连接方法十... 在手竿主线与竿梢蛇口线的连接上,不少钓友采用“活结法”。即在主线一端10厘米处回折后打上下两个结,组装时将食指、中指插入两结间后翻转勾出一活扣,然后将它套在事先已在竿梢蛇口线末端打好的一死结后方拉紧即可。此种连接方法十分实用,但美中不足的是在垂钓过程中有松脱的可能, 展开更多
关键词 钓鱼 钓具 蛇口线 活结法
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Structure for energy cycle: a unique status of the second law of thermodynamics for living systems 被引量:1
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作者 Shunong Bai Hao Ge Hong Qian 《Science China(Life Sciences)》 SCIE CAS CSCD 2018年第10期1266-1273,共8页
Distinguishing things from beings, or matters from lives, is a fundamental question. Extending E. Schr?dinger's neg-entropy and I. Prigogine's dissipative structure, we propose a chemical kinetic view that the... Distinguishing things from beings, or matters from lives, is a fundamental question. Extending E. Schr?dinger's neg-entropy and I. Prigogine's dissipative structure, we propose a chemical kinetic view that the earliest "live" process is embedded essentially in a special interaction between a pair of specific components under a particular, corresponding environmental conditions. The interaction exists as an inter-molecular-force-bond complex(IMFBC) that couples two separate chemical processes: one is the spontaneous formation of the IMFBC driven by a decrease of Gibbs free energy as a dissipative process; while the other is the disassembly of the IMFBC driven thermodynamically by free energy input from the environment. The two chemical processes coupled by the IMFBC originated independently and were considered non-living on Earth, but the IMFBC coupling of the two can be considered as the earliest form of metabolism: the first landmark on the path from things to a being. The dynamic formation and disassembly of the IMFBC, as a composite individual, follows a principle designated as "… structure for energy for structure for energy…", the cycle continues; and for short it will be referred to as "structure for energy cycle". With additional features derived from this starting point, the IMFBC-centered "live" process spontaneously evolved into more complex living organisms with the characteristics currently known. 展开更多
关键词 structure energy living systems IMFBC CYCLE
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Clinical Observations on 100 Cases of Ulcerative Colitis Treated with the Method of Clearing Away Heat,Expelling Dampness,Promoting Blood Circulation and Healing Ulcer 被引量:3
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作者 叶柏 沈红 +2 位作者 陆乐 王亚奇 段树民 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2010年第2期98-102,共5页
Objective: To observe the clinical therapeutic effect of dampness, promoting blood circulation and healing ulcer on the method of clearing away heat, expelling ulcerative colitis. Methods: The 100 cases were randoml... Objective: To observe the clinical therapeutic effect of dampness, promoting blood circulation and healing ulcer on the method of clearing away heat, expelling ulcerative colitis. Methods: The 100 cases were randomly divided into a control group of 45 cases treated with retention enema of the enterosoluble tablet sulfasalazine once every evening and a treatment group of 55 cases treated with retention enema of the decoction for clearing away heat, expelling dampness, promoting blood circulation and healing ulcer once every evening. The patients in both groups orally took Chinese drug for basic treatment for 30 days as a course. After treatment, the clinical therapeutic effects in the 2 groups were compared and changed symptoms in intestinal mucosa were observed under endoscope. Results: The total effective rate of treatment group was better in relieving symptoms of TCM syndrome (90.9%) and intestinal mucosa (83.3%) than that of control group (68.9%, 56.3%) (P〈0.01 or P〈0.05). Conclusion: With good therapeutic effect on ulcerative colitis, Qinghua Huoxue Lianyang therapy (clearing away heat, expelling dampness, promoting blood circulation and healing ulcer) can obviously repair intestinal mucosa. 展开更多
关键词 Qinghua Huoxue Lianyang therapy herbal enema ulcerative colitis
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A simple electrochemical method for conversion of Pt wires to Pt concave icosahedra and nanocubes on carbon paper for electrocatalytic hydrogen evolution 被引量:6
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作者 Zhimin Luo Chaoliang Tan +11 位作者 Zhuangchai Lai Xiao Zhang Junze Chen Ye Chen Bo Chen Yue Gong Zhicheng Zhang Xuejun Wu Bing Li Yun Zong Lin Gu Hua Zhang 《Science China Materials》 SCIE EI CSCD 2019年第1期115-121,共7页
In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanost... In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl(3 mol L-1 KCl) are used as the counter, working and reference electrodes, respectively.Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals,such as Au and Pd, from their bulk materials, which could exhibit various promising applications. 展开更多
关键词 noble metals electrochemical conversion concave nanostructures ELECTROCATALYSIS hydrogen evolution
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On the Tangent Bundle of a Hypersurface in a Riemannian Manifold
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作者 Zhonghua HOU Lei SUN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第4期579-602,共24页
Let (Mn, g) and (N^n+1, G) be Riemannian manifolds. Let TMn and TN^n+1 be the associated tangent bundles. Let f : (M^n, g) → (N^+1, G) be an isometrical immersion with g = f^*G, F = (f, df) : (TM^n,g... Let (Mn, g) and (N^n+1, G) be Riemannian manifolds. Let TMn and TN^n+1 be the associated tangent bundles. Let f : (M^n, g) → (N^+1, G) be an isometrical immersion with g = f^*G, F = (f, df) : (TM^n,g) → (TN^n+1, Gs) be the isometrical immersion with g= F*Gs where (df)x : TxM → Tf(x)N for any x∈ M is the differential map, and Gs be the Sasaki metric on TN induced from G. This paper deals with the geometry of TM^n as a submanifold of TN^n+1 by the moving frame method. The authors firstly study the extrinsic geometry of TMn in TN^n+1. Then the integrability of the induced almost complex structure of TM is discussed. 展开更多
关键词 HYPERSURFACES Tangent bundle Mean curvature vector Sasaki metric Almost complex structure Kghlerian form
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Upper crustal P-wave velocity structure beneath two volcanic areas in northern Iran
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作者 LU Yan CHEN Ling 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第4期786-795,共10页
Detailed information about the crustal structure is essential for better understanding the occurrence and mechanisms of earthquakes and volcanoes.Here we present a study of the upper crustal P-wave velocity structure ... Detailed information about the crustal structure is essential for better understanding the occurrence and mechanisms of earthquakes and volcanoes.Here we present a study of the upper crustal P-wave velocity structure of two seismically and volcanically active areas in northern Iran using the two-dimensional Pg travel time tomography method.The imaging results suggest low velocities in the upper crust beneath the Damavand and Sahand-Sabalan volcanic areas in the central and western parts of northern Iran,respectively.The upper crustal low velocities in these two areas roughly coincide with previously imaged low Pn velocity anomalies,suggesting that the Late Cenozoic volcanic activity was probably caused by the upwelling of hot materials from the mantle.The image feature of the Pg velocity structure beneath the Sahand-Sabalan volcanic area further indicates that the hot materials stored in the upper crust beneath Sahand may be larger in size than those stored beneath Sabalan.Comparison of the Pg velocity images with the earthquake distribution in north Iran suggests that earthquakes mainly occur at moderately low velocity or low to high velocity boundary areas instead of significantly low or high velocity regions.The anisotropy results show that the Pg wave fast direction is consistent with the GPS direction at high Pg velocity areas and the fast direction is inconsistent with the GPS direction but consistent with the strike direction of faults at low velocity areas.Our new upper crustal structural images provide the basic observation for better understanding of the regional seismicity and volcanism,and link the surface geological phenomena to deep crustal and mantle processes associated with the active tectonics in northern Iran. 展开更多
关键词 Equatorial ionization anomaly Sudden stratospheric warming Ionosphere
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