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1高通量测序和DGGE分析土壤微生物群落的技术评价显示文摘【目的】比较新一代高通量测序与传统的变性梯度凝胶电泳(Denaturing Gradient Gel Electrophoresis,DGGE)指纹图谱技术,评价两种技术研究土壤微生物群落结构的优缺点。【方法】针对新西兰典型草地和森林土壤,以16S rRNA基因为标靶,通过高通量测序和DGGE技术分析土壤微生物群落的组成、丰度和多样性,比较两种方法在土壤微生物研究中的适用性。【结果】在不同的微生物分类水平,高通量测序草地土壤检测到22门,54纲,60目,131科,350属;而DGGE仅检测到6门,9纲,8目,10科,10属,表明DGGE显著低估了土壤微生物的群落组成。森林土壤也得到了类似规律,高通量测序的检测灵敏度是DGGE的3.8、6.7、6.4、19.2及39.4倍。进一步分析土壤中主要微生物类群的相对丰度,发现分类水平越低,高通量测序与DGGE的结果差异越大,尤其在科和属的水平上差异最大。以高通量测序结果为标准,DGGE明显高估了土壤中大多数微生物类群的相对丰度,最高可达2000倍。两种方法都表明草地土壤的多样性指数高于森林土壤,但DGGE多样性指数的绝对值远低于高通量测序结果。【结论】高通量测序能够较为全面和准确的反映土壤微生物群落结构,而DGGE仅能够反映有限的优势微生物类群,在很大程度上极可能低估土壤微生物的物种组成并高估其丰度。夏围围 贾仲君 2014微生物学报2014,54,12:151
2Use of portal pressure studies in the management of variceal haemorrhage显示文摘Portal hypertension occurs as a complication of liver cirrhosis and complications such as variceal bleeding lead to significant demands on resources. Endoscopy is the gold standard method for screening cirrhotic patients however universal endoscopic screening may mean a lot of unnecessary procedures as the presence of oesophageal varices is variable hence a large time and cost burden on endoscopy units to carry out both screening and subsequent follow up of variceal bleeds. A less invasive method to identify those at high risk of bleeding would allow earlier prophylactic measures to be applied. Hepatic venous pressure gradient (HVPG) is an acceptable indirect measurement of portal hypertension and predictor of the complications of portal hypertension in adult cirrhotics. Varices develop at a HVPG of 10-12 mmHg with the appearance of other complications with HPVG > 12 mmHg. Variceal bleeding does not occur in pressures under 12 mmHg. HPVG > 20 mmHg measured early after admission is a significant prognostic indicator of failure to control bleeding varices, indeed early transjugular intrahepatic portosystemic shunt (TIPS) in such circumstances reduces mortality significantly. HVPG can be used to identify responders to medical therapy. Patients who do not achieve the suggested reduction targets in HVPG have a high risk of rebleeding despite endoscopic ligation and may not derive significant overall mortality benefit from endoscopic intervention alone, ultimately requiring TIPS or liver transplantation. Early HVPG measurements following a variceal bleed can help to identify those at risk of treatment failure who may benefit from early intervention with TIPS. Therefore, we suggest using HVPG measurement as the investigation of choice in those with confirmed cirrhosis in place of endoscopy for intitial variceal screening and, where indicated, a trial of B-blockade, either intravenously during the initial pressure study with assessment of response or oral therapy with repeat HVPG six weeks later. In those with elevated pressures, primary medical prophylaxis could be commenced with subsequent close monitoring of HVPG thus negating the need for endoscopy at this point. All patients presenting with variceal haemorrhage should undergo HVPG measurement and those with a gradient greater than 20 mmHg should be considered for early TIPS. By introducing portal pressure studies into a management algorithm for variceal bleeding, the number of endoscopies required for further intervention and follow up can be reduced leading to significant savings in terms of cost and demand on resources.Jennifer Addley Tony CK Tham William Jonathan Cash 2012World Journal of Gastrointestinal Endoscopy2012,4,7:37
3Homogenization of temperature field and temperature gradient field显示文摘The homogenization of temperature field and temperature gradient field are very important for many devices, systems and equipments, such as satellites and electronic devices. This paper discusses the distribution optimization of the limited high conductivity material with the simulated annealing algorithm to homogenize the temperature field in a two-dimensional heat conduction problem. At the same time, the temperature gradient field is homogenized with the bionic optimization method. The results show that the two optimization targets are consistent to some extent, while the bionic optimization method could save much computing time. In addition, there are threshold values for the amount of high conductivity material and the ratio of the high conductivity to the low conductivity beyond which further increasing these values brings very little improvement on the homogenization of temperature field and temperature gradient field.CHENG XueTao XU XiangHua LIANG XinGang 2009Science China(Technological Sciences)2009,52,10:35
4Spatiotemporal dynamics of aboveground primary productivity along a precipitation gradient in Chinese temperate grassland显示文摘Investigating the spatial and temporal variance in productivity along natural precipitation gradients is one of the most efficient approaches to improve understanding of how ecosystems respond to climate change. In this paper, by using the natural precipitation gradient of the Inner Mongolian Plateau from east to west determined by relatively long-term observations, we analyzed the temporal and spatial dynamics of aboveground net primary productivity (ANPP) of the temperate grasslands covering this region. Across this grassland transect, ANPP increased exponentially with the increase of mean annual precipitation (MAP) (ANPP=24.47e0.005MAP, R2=0.48). Values for the three vegetation types desert steppe, typical steppe, and meadow steppe were: 60.86 gm-2a-1, 167.14 gm-2a-1 and 288.73 gm-2a-1 respectively. By contrast, temperature had negative effects on ANPP. The moisture index (K ), which takes into ac- count both precipitation and temperature could explain the spatial variance of ANPP better than MAP alone (ANPP=2020.34K1.24, R2=0.57). Temporally, we found that the inter-annual variation in ANPP (cal- culated as the coefficient of variation, CV) got greater with the increase of aridity. However, this trend was not correlated with the inter-annual variation of precipitation. For all of the three vegetation types, ANPP had greater inter-annual variation than annual precipitation (PPT). Their difference (ANPP CV/PPT CV) was greatest in desert steppe and least in meadow steppe. Our results suggest that in more arid regions, grasslands not only have lower productivity, but also higher inter-annual variation of production. Climate change may have significant effects on the productivity through changes in precipitation pattern, vegetation growth potential, and species diversity.HU ZhongMin FAN JiangWen ZHONG HuaPing YU GuiRui 2007Science China Earth Sciences2007,50,5:23
5ZnO varistors with high voltage gradient and low leakage current by doping rare-earth oxide显示文摘The surge arrester of 1000 kV gas-insulated substation (GIS) needs ZnO varistor with high voltage gradient to effectively improve the potential distribution along ZnO varistor column inside the metal-oxide surge arresters. In this paper, the elec-trical and structural parameters of ZnO varistors are changed by doping with some rare-earth oxides, and the mechanism which leads these changes is discussed. When rare-earth oxide additives are added into ZnO varistors, the growing speed is slowed down due to the stabilization of the new spinel phases formed in the grain-boundary by rare-earth oxide additives, then the size of ZnO grains is smaller, and the voltage gradient of varistor increases obviously. By adding suitable amount of oxides of metal Co and Mn, the leakage current can be effectively decreased and the nonlinearity coefficient increased. The novel ZnO varistor samples sintered with the optimal additives have a voltage gradient of 492 V/mm, and the nonlinearity coefficient of 76, but their leakage currents are only 1 μA.HE JinLiang HU Jun LIN YuanHua 2008Science China(Technological Sciences)2008,51,6:21
6Osteopontin: A non-invasive parameter of portal hypertension and prognostic marker of cirrhosis显示文摘AIM: To investigate the relationship between osteopontin plasma concentrations and the severity of portal hypertension and to assess osteopontin prognostic value.METHODS: A cohort of 154 patients with confirmed liver cirrhosis(112 ethylic, 108 men, age 34-72 years)were enrolled in the study. Hepatic venous pressure gradient(HVPG) measurement and laboratory and ultrasound examinations were carried out for all patients. HVPG was measured using a standard catheterization method with the balloon wedge technique. Osteopontin was measured using the enzyme-linked immunosorbent assay(ELISA) method in plasma. Patients were followed up with a specific focus on mortality. The control group consisted of 137 healthy age- and sex- matched individuals.RESULTS: The mean value of HVPG was 16.18 ± 5.6 mm Hg. Compared to controls, the plasma levels of osteopontin in cirrhotic patients were significantly higher(P < 0.001). The plasma levels of osteopontin were positively related to HVPG(P = 0.0022, r = 0.25) and differed among the individual Child-Pugh groups of patients. The cut-off value of 80 ng/m L osteopontin distinguished patients with significant portal hypertension(HVPG above 10 mm Hg) at 75% sensitivity and 63% specificity. The mean follow-up of patients was 3.7 ± 2.6 years. The probability of cumulative survival was 39% for patients with HVPG > 10 mm Hg and 65% for those with HVPG ≤ 10 mm Hg(P = 0.0086, odds ratio(OR), 2.92, 95% confidence interval(CI): 1.09-7.76). Osteopontin showed a similar prognostic value to HVPG. Patients with osteopontin values above 80 ng/m L had significantly lower cumulative survival compared to those with osteopontin ≤ 80 ng/m L(37% vs 56%, P = 0.00035; OR = 2.23, 95%CI: 1.06-4.68).CONCLUSION: Osteopontin is a non-invasive parameter of portal hypertension that distinguishes patients with clinically significant portal hypertension. It is a strong prognostic factor for survival.Radan Bruha Marie Jachymova Jaromir Petrtyl Karel Dvorak Martin Lenicek Petr Urbanek Tomislav Svestka Libor Vitek 2016World Journal of Gastroenterology2016,22,12:20
7Management of small hepatocellular carcinoma in cirrhosis:Focus on portal hypertension显示文摘The incidence of hepatocellular carcinoma(HCC) is rising worldwide being currently the fifth most common cancer and third cause of cancer-related mortality.Early detection of HCC through surveillance programs have enabled the identification of small nodules with higher frequency,and nowadays account for 10%-15% of patients diagnosed in the West and almost 30% in Japan.Patients with small HCC can be candidates for potential curative treatments:liver transplantation,surgical resection and percutaneous ablation,depending on the presence of portal hypertension and co-morbidities.This review will analyze recent advancements in the clinical management of these individuals,focusing on issues related to the role of portal hypertension,the debate between resection and ablative therapies and the future impact of molecular technologies.Virginia Hernandez-Gea Fanny Turon Annalisa Berzigotti Augusto Villanueva 2013World Journal of Gastroenterology2013,19,8:20
8A Liutex based definition and identification of vortex core center lines显示文摘Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient.Yi-sheng Gao Jian-ming Liu Yi-fei Yu Chaoqun Liu 2019Journal of Hydrodynamics2019,31,3:19
9不同性状窖泥的细菌群落结构与酸酯含量分析显示文摘为了解不同性状窖泥细菌群落结构及酸酯代谢的差异,分别选取新窖泥、趋老熟窖泥和老熟窖泥,对其细菌16S r DNA的V3区进行变性梯度凝胶电泳分析和同源性比较,并结合窖泥主要有机酸及有机酸酯含量进行了典型相关分析。结果表明,老熟窖泥的细菌多样性指数及均匀度指数高于新窖泥和趋老熟窖泥,得到的39个优势条带,进行细菌DNA测序可分为14类;Clostridium XIVa、Aminobacterium均只在老熟窖泥中检测到;新窖泥和趋老熟窖泥与Lactococcus、Lactobacillus、乳酸、乳酸乙酯含量正相关,老熟窖泥与Clostridiales、己酸、己酸乙酯和丁酸含量正相关。袁玉菊 张倩颖 曾丽云 张文学 2017食品与发酵工业2017,43,1:17
10Al_(80)Ni_6Y_8Co_4Cu_2 GLASS ALLOYS CONTAINING NANOSCALEPARTICLES BY ISOTHERMAL ANNEALING OR QUENCHING显示文摘Al80Ni6 Y8 Co4 Cu2 amorphous ribbons were isothermally annealed and a mixed structure consisting of α-Al particle with a size of less than 15nm and Al3Ni compound with a size of about 30nm was obtained. The crystallization kinetics of Al80Ni6 Y8 Co4 Cu2 amorphous alloy shows that the precipitation of α-Al particles is the growth process controlled by diffusion of the solute elements rejected from the growing crystals. By quenching at different cooling rates, a mixed structure consisting of nanoscale α-Al particles and the remaining glass matrix or structure consisting of nanoscale particle (Al phase or Al3Ni compound) with a size of about 100nm was formed. The addition of Co elements and Cu elements to Al-Ni-Y alloy systems increases the glass formation ability of the alloy and the thermal stability of the supercooled liquid region against crystallization, which results from significant difference of atomic size, strong bonding nature among constituent elements and the low diffisivity of the solute elements due to the concentration gradient in the growing front of crystals.Z. Bian, G. He and G.L. Chen (State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China) J. Lu, D.J. Chen, G.C. Tu, G.J. Chen and X.J. Hu (Shougang Metallurgical Research Institute, Beijing 2000Acta Metallurgica Sinica(English Letters)2000,13,5:16
11Double-stream-pouring technique for production of gradient materials by continuous casting显示文摘A novel method for producing gradient materials by continuous casting is introduced. By using many-stream-pouring technique, samples with gradient distribution of alloy composition along the cross section have been prepared. The main difference of this method from the conventional continuous casting is the pouring system equipped with two sets of tundishes for liquid metals of different alloy compositions. Special consideration is given to the promotion and control of the cross-sectional mass transport. The steady heat transfer and mass flow ensure a partial mixing of two metals and yield a continously varying composition distribution. By adjusting the processing parameters, composition profile with different shapes can be achieved. First experiments have been carried out in Al-Si system and Al-Cu system for three series of Al/AlSi, AlSi/Al and AlCu/Al. It is shown that the alloy composition, the microstructure and the mechanical property change smoothly from the centre to the surface of the samples. This simple and practical method is potential for mass prodution of 'structural gradient materials' and may offer a new way for alloy design.Zhang Weiwen Zhu Cangshan Wei Xingzhao Meng Jilong Yuan Shugui Yu Ge 1998Chinese Science Bulletin1998,43,11:16
12Further insight into the convergence of the Fletcher-Reeves method显示文摘The convergence properties of the Fletcher-Reeves method for unconstrained optimization are further studied with the technique of generalized line search. Two conditions are given which guarantee the global convergence of the Fletcher-Reeves method using generalized Wolfe line searches or generalized Arjimo line searches, whereas an example is constructed showing that the conditions cannot be relaxed in certain senses.戴彧虹 1999Science China Mathematics1999,42,9:16
13Preparation of 2024/3003 gradient materials by semi-continuous casting using double-stream-pouring technique显示文摘The 2024/3003 aluminum gradient alloys are prepared by semi continuous casting. The influences of throttle bore diameter of embedded nozzle and temperature of internal melt on composition distribution, macrostructure, hardness are analyzed, and the stability of gradient distribution of composition, macrostructure and hardness along the axial direction of the ingot is also studied. The results show that diffe rent composition profiles can be achieved by adjusting the processing parameters; the volume fraction of inner alloy in the ingot can be increased by enlarging the throttle bore diameter and elevating the temperature of inner melt; quasi steady solidification can be realized within 20 s during cast processing, and consistent quality ingot is obtained by controlling the casting speed and liquid height of inner melt.李元元 费劲 陈维平 张卫文 邵明 2002Journal of Central South University of Technology2002,9,4:14
14A REGULARIZED CONJUGATE GRADIENT METHOD FOR SYMMETRIC POSITIVE DEFINITE SYSTEM OF LINEAR EQUATIONS显示文摘AbstractA class of regularized conjugate gradient methods is presented for solving the large sparse system of linear equations of which the coefficient matrix is an ill-conditioned symmetric positive definite matrix. The convergence properties of these methods are discussed in depth, and the best possible choices of the parameters involved in the new methods are investigated in detail. Numerical computations show that the new methods are more efficient and robust than both classical relaxation methods and classical conjugate direction methods.Zhong-zhi Bai Shao-liang Zhang 2002Journal of Computational Mathematics2002,20,4:13
15Effects of narrow plant spacing on root distribution and physiological nitrogen use efficiency in summer maize显示文摘The objective of this study was to understand the effects of plant spacing on grain yield and root competition in summer maize(Zea mays L.). Maize cultivar Denghai 661 was planted in rectangular tanks(0.54 m × 0.27 m × 1.00 m) under 27 cm(normal) and 6 cm(narrow) plant spacing and treated with zero and 7.5 g nitrogen(N) per plant. Compared to normal plant spacing, narrow plant spacing generated less root biomass in the 0–20 cm zone under both N rates, slight reductions of dry root weight in the 20–40 cm and 40–70 cm zones at the mid-grain filling stage, and slight variation of dry root weights in the 70–100 cm zone during the whole growth period. Narrow plant spacing decreased root reductive activity in all root zones, especially at the grain-filling stage. Grain yield and above-ground biomass were 5.0% and 8.4% lower in the narrow plant spacing than with normal plant spacing, although narrow plant spacing significantly increased N harvest index and N use efficiency in both grain yield and biomass, and higher N translocation rates from vegetative organs. These results indicate that the reductive activity of maize roots in all soil layers and dry weights of shallow roots were significantly decreased under narrow plant spacing conditions, resulting in lower root biomass and yield reduction at maturity. Therefore, a moderately dense sowing is a basis for high yield in summer maize.Wenshun Jiang Kongjun Wang Qiuping Wu Shuting Dong Peng Liu Jiwang Zhang 2013The Crop Journal2013,1,1:13
16DESIGN AND PROPERTIES OF A FUNCTIONALLY GRADIENT CERAMIC TOOL MATERIAL显示文摘Based on the analyses of the severity of cutting process as well as the failure mechanisms of ceramic tools, a model for designing functionally gradient ceramic tool materials with symmetrical distribution is presented, by which a Al 2O 3/(W,Ti)C ceramic tool material FG 2 was developed. Multi objective optimization method was employed in designing the compositional distribution of this ceramic tool material. The results of both continuous and intermittent cutting tests are indicative of the much better cutting behavior of the functionally gradient ceramic tool FG 2 than that of the common ceramic tool SG 4.J. Zhao,X. Ai, J.H. Zhang, J.X. Deng and C.Z. Huang Department of Mechanical Engineering, Shandong University of Technology, Jinan 250061,China 1999Acta Metallurgica Sinica(English Letters)1999,12,5:13
17Intracoronary pressure gradient measurement in acute myocardial infarction patients with the no-reflow phenomenon during primary percutaneous coronary intervention显示文摘Background:Various experimental and clinical studies have reported on coronary microcirculatory dysfunction('no-reflow'phenomenon).Nevertheless,pathogenesis and effective treatment are yet to be fully elucidated.This study aimed to measure the intracoronary pressure gradient in the no-reflow artery during emergent percutaneous coronary intervention and explore the potential mechanism of no-reflow.Methods:From September 1st,2018 to June 30th,2019,intracoronary pressure in acute myocardial infarction patient was continuously measured by aspiration catheter from distal to proximal segment in the Department of Coronary Care Unit,Tianjin Chest Hospital,respectively in no-reflow arteries(no-reflow group)and arteries with thrombolysis in myocardial infarction-3 flow(control group).At least 12 cardiac cycles were consecutively recorded when the catheter was pulled back.The forward systolic pressure gradient was calculated as proximal systolic pressure minus distal systolic pressure.Comparison between groups was made using the Student t test,Mann-Whitney U-test or Chi-square test,as appropriate.Results:Intracoronary pressure in 33 no-reflow group and 26 in control group were measured.The intracoronary forward systolic pressure gradient was-1.3(-4.8,0.7)and 3.8(0.8,8.8)mmHg in no-reflow group and control group(Z=-3.989,P<0.001),respectively,while the forward diastolic pressure gradient was-1.0(-3.2,0)and 4.6(0,16.5)mmHg in respective groups(Z=-3.851,P<0.001).Moreover,the intracoronary forward pressure gradient showed significant difference between that before and after nicorandil medication(Z=-3.668,P<0.001 in systolic pressure gradient and Z=-3.530,P<0.001 in diastolic pressure gradient).Conclusions:No reflow during emergent coronary revascularization is significantly associated with local hemodynamic abnormalities in the coronary arteries.Intracoronary nicorandil administration at the distal segment of a coronary artery with an aspiration catheter could improve the microcirculatory dysfunction and resume normal coronary pressure gradient.Clinical trial registration:www.ClinicalTrials.gov(No.NCT 03600259).Ming-Dong Gao En-Yuan Zhang Yuan-Ying Liu Xiao-Wei Li Jian-Yong Xiao Gen-Yi Sun Yin Liu 2020Chinese Medical Journal2020,,7:12
18A general theoretical principle for single-phase convection heat transfer enhancement显示文摘The main methods of single-phase convection heat transfer enhancement are analyzed in this paper, and the unity of contradiction between heat transfer enhancement and energy consumption(or exergy destruction)is expounded.The thermodynamic relationship between heat(or exergy)transfer efficiency and energy consumption(or exergy destruction)as well as driving forces is established,and a general theoretical principle for single-phase convection heat transfer enhancement is further obtained. The principle shows that temperature gradient field distribution and velocity field distribution constrain each other,and that the optimum heat transfer efficiency can be obtained when they are synergetic.If the level of the synergy of temperature gradient field distribution with velocity field distribution is determined,the relative uniform temperature gradient is required,and vice versa.The principle also shows the relationship of relative temperature gradient with specific heat and coefficient of heat conductivity.The deduced results can be used as a theoretical guidance for single-phase convection heat transfer enhancement and optimum design of heat exchangers.WANG SongPing CHEN QingLin ZHANG BingJian HUA Ben 2009Science China(Technological Sciences)2009,52,12:12
19PARTICULATE SIZE EFFECTS IN THE PARTICLE-REINFORCED METAL-MATRIX COMPOSITES显示文摘The influences of particle size on the mechanical properties of theparticulate metal matrix composite are obviously displayed in the experimental ob-servations. However, the phenomenon can not be predicted directly using the conven-tional elastic-plastic theory. It is because that no length scale parameters are involvedin the conventional theory. In the present research, using the strain gradient plas-ticity theory, a systematic research of the particle size effect in the particulate metalmatrix composite is carried out. The roles of many composite factors, such as: theparticle size, the Young’s modulus of the particle, the particle aspect ratio and vol-ume fraction, as well as the plastic strain hardening exponent of the matrix material,are studied in detail. In order to obtain a general understanding tor the compos-ite behavior, two kinds of particle shapes, ellipsoid and cylinder, are considered tocheck the strength dependence of the smooth or non-smooth particle surface. Finally,the prediction results will be applied to the several experiments about the ceramicparticle-reinforced metal-matrix composites. The material length scale parameter ispredicted.魏悦广 2001Acta Mechanica Sinica2001,17,1:12
20Comparison of hepatic venous pressure gradient and endoscopic grading of esophageal varices显示文摘AIM: To determine the correlation between the hepatic venous pressure gradient and the endoscopic grade of esophageal varices.METHODS: From September 2009 to March 2013, a total of 176 measurements of hepatic venous pressure gradient(HVPG) were done in 146 patients. Each transjugular HVPG was measured twice, first using an end whole catheter(EH-HVPG), and then using a balloon catheter(B-HVPG). The HVPG was compared with the endoscopic grade of esophageal varices(according to the general rules for recording endoscopic findings of esophagogastric varices), which was recorded within a month of the measurement of HVPG.RESULTS: The study included 110 men and 36 women, with a mean age of 56.1 years(range, 43-76 years). The technical success rate of the pressure measurements was 100% and there were no complication related to the procedures. Mean HVPG was 15.3 mm Hg as measured using the end hole catheter method and 16.5 mm Hg as measured using the balloon catheter method. Mean HVPG(both EHHVPG and B-HVPG) was not significantly different among patients with different characteristics, including sex and comorbid factors, except for cases with hepatocellular carcinoma(B-HVPG, P = 0.01; EH-HVPG, P = 0.02). Portal hypertension(> 12 mm Hg HVPG) occurred in 66% of patients according to EH-HVPG and 83% of patients according to B-HVGP, and significantly correlated with Child's status(B-HVPG, P < 0.000; EHHVGP, P < 0.000) and esophageal varies observed upon endoscopy(EH-HVGP, P = 0.003; B-HVGP, P = 0.006). One hundred and thirty-five endoscopies were performed, of which 15 showed normal findings, 27 showed grade 1 endoscopic esophageal varices, 49 showed grade 2 varices, and 44 showed grade 3 varices. When comparing endoscopic esophageal variceal grades and HVPG using univariate analysis, the P value was 0.004 for EH-HVPG and 0.002 for B-HVPG. CONCLUSION: Both EH-HVPG and B-HVPG showed a positive correlation with the endoscopic grade of esophageal varices, with B-HVPG showing a stronger correlation than EH-HVPG.Eun Ji Lee Yong Jae Kim Dong Erk Goo Seung Boo Yang Hyun-Joo Kim Jae Young Jang Soung Won Jeong 2016World Journal of Gastroenterology2016,22,11:11
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