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1Impact of periampullary diverticula on the outcome and fluoroscopy time in endoscopic retrograde cholangiopancreatography显示文摘BACKGROUND: It is unclear whether the presence of periampullary diverticula (PAD) affects technical success and complication rates during endoscopic retrograde cholangio- pancreatography (ERCP). Moreover, the impact of PAD on fluoroscopy duration is still unknown. The present study aimed to investigate the success rate and difficulty of common bile duct (CBD) cannulation, post-procedure complications and fluoroscopy duration in patients with and without PAD. METHODS: Patients from January 2008 to December 2010 with PAD (group A) and without PAD (group B) and similar indications for therapeutic ERCP were prospectively compared. The comparison included patient characteristics, findings of ERCP, and details of procedure and fluoroscopy time. The influence of papilla's location with respect to the diverticulum on procedure was also investigated. RESULTS: A total of 428 consecutive patients who had undergone therapeutic ERCP for similar indications were divided in two groups according to the presence (group A, 107 patients) or absence (group B, 321 patients) of PAD. The mean age and ASA score of the patients with PAD were significantly higher than those patients without PAD. The main indication was choledocholithiasis. Successful final CBD cannulation was achieved in 97.20% of the patients in group A vs 99.69% in group B (P=0.05). CBD diameter, number of stones and the largest stone size were significantly higher in group A thangroup B (P<0.001). Complete clearance of the CBD after the first attempt was achieved in 85.86% and 94.75% of the patients in groups A and B, respectively (P=0.03). In both groups, the time needed to complete the procedure and fluoroscopy time was significantly longer in patients with PAD (22.87 vs 18.99 minutes, P<0.001; 76.51 vs 47.42 seconds, P<0.001). There was no significant difference between the two groups in the complication rate. The type of papilla's location with respect to the diverticulum did not influence the total cannulation rate and post-procedure complications. CONCLUSION: The presence of a PAD does not affect the success rate and complications of therapeutic ERCP in expert hands; however, the fluoroscopy time is significantly longer in patients with PAD.Panagiotis Katsinelos Grigoris Chatzimavroudis Kostas Tziomalos Christos Zavos Athanasios Beltsis Georgia Lazaraki Sotiris Terzoudis Jannis Kountouras 2013Hepatobiliary & Pancreatic Diseases International2013,12,4:15
2掺硫硒化镓晶体在太赫兹波段的光学特性显示文摘利用太赫兹时域光谱技术测量了掺硫硒化镓(GaSe1-xSx)晶体在太赫兹波段的光学参数,包括折射系数、吸收系数等。使用自由空间电光取样法获得了太赫兹电磁波的脉冲波形,对不同硫掺杂量的硒化镓晶体进行了研究,在硫的掺杂量为0,0.01,0.14,0.26,0.37时,在0.22.0 THz测得了GaSe1-xSx的折射系数、吸收系数等光学参数。此外还在吸收光谱上观察到E′^(2)和E″^(2)两个声子振动模态,其强度与频率会随着硫的掺杂量而改变,且即使是微量的硫掺杂也会影响吸收光谱上的声子振动模态。最后,在相位匹配ee-e的条件下,模拟了利用锁模钛蓝宝石激光使此类晶体产生太赫兹辐射的可能性。罗志伟 古新安 朱韦臻 唐维聪 ANDREEV YURY LANSKII Grigory MOROZOV Alexander ZUEV Vladimir 2011光学精密工程2011,19,2:10
3Effects of Helicobacterpyloriinfection on gastric emptying rate in patients with non-ulcer dyspepsia显示文摘AIM: The pathogenesis of delayed gastric emptying in patients with non-ulcer dyspepsia (NUD) remains unclear. We aimed to examine whether gastric emptying rate in NUD patients was associated with Helicobacterpylori(Hpylori) infection and whether it was affected by eradication of the infection. METHODS: Gastric emptying rate of a mixed solid-liquid meal was assessed by the paracetamol absorption method in NUD patients and asymptomatic controls (n=-17). Hpylori status was assessed by serology and biopsy urease test. Hpylori-positive NUD patients (n=-23) received 10-day triple eradication therapy. H pylori status was re-assessed by biopsy urease test four weeks later, and if eradication was confirmed, gastric emptying rate was re-evaluated. RESULTS: Thirty-three NUD patients and 17 controls were evaluated. NUD patients had significantly delayed gastric emptying compared with controls. The mean maximum plasma paracetamol concentration divided by body mass (Cmax/BM) was 0.173 and 0.224 mg/L.kg respectively (P=0.02), the mean area under plasma paracetamol concentration-time curve divided by body mass (AUC/BM) was 18.42 and 24.39 mg.min/L.kg respectively (P=-0.01). Gastric emptying rate did not differ significantly between H pylori-positive and H pylori-negative NUD patients. The mean Cmax/BM was 0.172 and 0.177 mg/Ukg respectively (P=-0.58), the mean AUC/BM was 18.43 and 18.38 rag.min/L.kg respectively (P=0.91). Among 14 NUD patients who were initially H pylori-positive, confirmed eradication of the infection did not significantly alter gastric emptying rate. The mean Cmax/BM was 0.171 and 0.160 mg/Ukg before and after Hp eradication, respectively (P=0.64), the mean AUC/BM was 17.41 and 18.02 mg.min/Ukg before and after eradication, respectively (P=-0.93). CONCLUSION: Although gastric emptying is delayed in NUD patients compared with controls, gastric emptying rate is not associated with H pylori status nor it is affected by eradication of the infection.Grigoris I Leontiadis George I Minopoulos Efstratios Maltezos Stamatia Kotsiou Konstantinos I Manolas Konstantinos Simopoulos Dimitrios Hatseras 2004World Journal of Gastroenterology2004,10,12:9
4微波预处理加速阔叶树材干燥的技术分析显示文摘微波用于阔叶树木材预处理,可缩短木材的干燥时间;降低木材干燥降等损失、增加高质量木材出材率,为大截面木材干燥提供了可能性;减少了贮存场地及占用资金,降低了木材运输费用。澳大利亚的应用研究结果表明,微波处理费用只占低质量木材价格的4.1%~4.9%,或高质量木材价格的2.3%~2.8%。周永东 Grigory Torgovnikov Peter Vinden 傅峰 2011木材工业2011,25,1:7
5Clinical significance of mesenteric panniculitis-like abnormalities on abdominal computerized tomography in patients with malignant neoplasms显示文摘AIM To clarify the association of malignancy with mesenteric panniculitis-like changes on computed tomography(CT).METHODS All abdominal CT scans performed at North Shore University HealthS ystem showing mesenteric panniculitis from January 2005 to August 2010 were identified in the Radnet(Rad Net Corporation, Los Angeles, CA) database. Patients with a new or known diagnosis of a malignancy were included for this analysis. Longitudinal clinical histories were obtained from electronic medical records.RESULTS In total, 147794 abdominal CT scans were performed during the study period. Three hundred and fiftynine patients had mesenteric panniculitis(MP)-like abnormalities on their abdominal CT. Of these patients, 81 patients(22.6%) had a known history of cancer at the time of their CT scan. Nineteen(5.3%) had a new diagnosis of cancer in concurrence with their CT, but the majority of these(14/19, 74%) were undergoing CT as part of a malignancy evaluation. Lymphomas were the most common cancers associated with MPlike findings on CT(36 cases, 36%), with follicular lymphoma being the most frequent subtype(17/36). A variety of solid tumors, most commonly prostate(7) and renal cell cancers(6) also were seen. CT follow up was obtained in 56 patients. Findings in the mesentery were unchanged in 45(80%), worsened in 6(11%), and improved in 5 patients(9%). Positron emission tomography(PET) scans performed in 44 patients only showed a positive uptake in the mesenteric mass in 2 patients(5%). CONCLUSION A new diagnosis of cancer is uncommon in patients with CT findings suggestive of MP. MP-like mesenteric abnormalities on CT generally remain stable in patients with associated malignancies. PET scanning is not recommended in the evaluation of patients with mesenteric panniculitis-like findings on CT.Eli D Ehrenpreis Grigory Roginsky Richard M Gore 2016World Journal of Gastroenterology2016,22,48:7
6Combined endoscopic and ursodeoxycholic acid treatment of biliary cast syndrome in a non-transplant patient显示文摘A 76-year-old diabetic man underwent cholecystectomy for gangrenous calculous cholecystitis. His postoperative course was complicated by the development of Candida albicans esophagitis necessitating antifungal therapy, and total parenteral nutrition (TPN) for 15 d. Seven weeks after cholecystectomy, he presented with cholangitis. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated extrahepatic filling defects. Despite endoscopic extraction of a biliary cast, cholestasis remained unchanged. Oral administration of ursodeoxycholic acid (UDCA), 750 mg/d, resulted in normalization of liver function tests. We, therefore, propose for the f irst time, combined endoscopic plus UDCA treatment for the management of biliary cast syndrome.Panagiotis Katsinelos Jannis Kountouras Grigoris Chatzimavroudis Christos Zavos Ioannis Pilpilidis George Paroutoglou 2008World Journal of Gastroenterology2008,14,33:7
7Methods of computed tomography screening and management of lung cancer in Tianjin: design of a population-based cohort study显示文摘Objective: European lung cancer screening studies using computed tomography(CT) have shown that a management protocol based on measuring lung nodule volume and volume doubling time(VDT) is more specific for early lung cancer detection than a diameter-based protocol. However, whether this also applies to a Chinese population is unclear. The aim of this study is to compare the diagnostic performance of a volume-based protocol with a diameter-based protocol for lung cancer detection and optimize the nodule management criteria for a Chinese population.Methods: This study has a population-based, prospective cohort design and includes 4000 participants from the Hexi district of Tianjin, China. Participants will undergo low-dose chest CT at baseline and after 1 year. Initially, detected lung nodules will be evaluated for diameter and managed according to a routine diameter-based protocol(Clinical Practice Guideline in Oncology for Lung Cancer Screening, Version 2.2018). Subsequently, lung nodules will be evaluated for volume and management will be simulated according to a volume-based protocol and VDT(a European lung nodule management protocol). Participants will be followed up for 4 years to evaluate lung cancer incidence and mortality. The primary outcome is the diagnostic performance of the European volume-based protocol compared to diameter-based management regarding lung nodules detected using low-dose CT.Results: The diagnostic performance of volume-and diameter-based management for lung nodules in a Chinese population will be estimated and compared.Conclusions: Through the study, we expect to improve the management of lung nodules and early detection of lung cancer in Chinese populations.Yihui Du Yingru Zhao Grigory Sidorenkov Geertruida H.de Bock Xiaonan Cui Yubei Huang Monique D.Dorrius Mieneke Rook Harry J.M.Groen Marjolein A.Heuvelmans Rozemarijn Vliegenthart Kexin Chen Xueqian Xie Shiyuan Liu Matthijs Oudkerk Zhaoxiang Ye 2019Cancer Biology & Medicine2019,16,1:7
8Influence of hepatitis viruses on clinico-pathological profiles and long-term outcome in patients undergoing surgery for hepatocellular carcinoma显示文摘BACKGROUND: The global risk of hepatocellular carcinoma(HCC) is largely due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In recent years, however, an increased prevalence of non-viral HCC has been noted. The clinical impact of the presence/absence of viral infections in HCC remains controversial. The present study aimed to assess the effect of hepatitis viruses on demographics, clinical and pathological features and long-term outcome in a large cohort of Romanian patients who underwent surgery for HCC. METHODS: The study included 404 patients with HCC who had undergone resection, transplantation or radiofrequency ablation at a single institution between 2001 and 2010. The patients were divided into four groups: 85 patients with hepatitis B virus infection (HBV group), 164 patients with hepatitis C virus infection (HCV group), 39 patients with hepatitis B and C virus co-infection (HBCV group), and 116 patients without viral infection (non-BC group). RESULTS: The patients of both HBV (56.0±11.3 years) and HBCV groups (56.0±9.9 years) were significantly younger than those of the HCV (61.0±8.5 years, P=0.001) and non-BC groups(61.0±13.0 years, P=0.002). Interestingly, the prevalence of liver cirrhosis was significantly lower in the non-BC group (47%)than in any other subsets (72%-90%, P<0.002). Furthermore, the non-BC patients were more advanced according to the Barcelona Clinic Liver Cancer stages than the patients of the HCV or HBCV groups (P<0.020); accordingly, they were more frequently assessed beyond the Milan criteria than any other groups (P=0.001). No significant differences in the disease-free or overall survival rates were observed among these groups. CONCLUSIONS: Patients with non-viral HCC are diagnosed at advanced ages and stages, a situation plausibly due to the poor effectiveness of cancer surveillance in community practice. The presence of viral infections does not appear to impair the longterm prognosis after surgical treatment in patients with HCC; however, there is a trend for worse disease-free survival rates in HBCV patients, though statistical significance was not reached.Anna-Maria Tanase Traian Dumitrascu Simona Dima Razvan Grigorie Agnes Marchio Pascal Pineau Irinel Popescu 2014Hepatobiliary & Pancreatic Diseases International2014,13,2:7
9Proportional fuzzy feed-forward architecture control validation by wind tunnel tests of a morphing wing显示文摘In aircraft wing design,engineers aim to provide the best possible aerodynamic performance under cruise flight conditions in terms of lift-to-drag ratio.Conventional control surfaces such as flaps,ailerons,variable wing sweep and spoilers are used to trim the aircraft for other flight conditions.The appearance of the morphing wing concept launched a new challenge in the area of overall wing and aircraft performance improvement during different flight segments by locally altering the flow over the aircraft's wings.This paper describes the development and application of a control system for an actuation mechanism integrated in a new morphing wing structure.The controlled actuation system includes four similar miniature electromechanical actuators disposed in two parallel actuation lines.The experimental model of the morphing wing is based on a full-scale portion of an aircraft wing,which is equipped with an aileron.The upper surface of the wing is a flexible one,being closed to the wing tip;the flexible skin is made of light composite materials.The four actuators are controlled in unison to change the flexible upper surface to improve the flow quality on the upper surface by delaying or advancing the transition point from laminar to turbulent regime.The actuators transform the torque into vertical forces.Their bases are fixed on the wing ribs and their top link arms are attached to supporting plates fixed onto the flexible skin with screws.The actuators push or pull the flexible skin using the necessary torque until the desired vertical displacement of each actuator is achieved.The four vertical displacements of the actuators,correlated with the new shape of the wing,are provided by a database obtained through a preliminary aerodynamic optimization for specific flight conditions.The control system is designed to control the positions of the actuators in real time in order to obtain and to maintain the desired shape of the wing for a specified flight condition.The feasibility and effectiveness of the developed control system by use of a proportional fuzzy feed-forward methodology are demonstrated experimentally through bench and wind tunnel tests of the morphing wing model.Michel Joёl Tchatchueng Kammegne Ruxandra Mihaela Botez Lucian Teodor Grigorie Mahmoud Mamou Youssef Mebarki 2017Chinese Journal of Aeronautics2017,30,2:6
10Control of PHERES1 Imprinting in Arabidopsis by Direct Tandem Repeats显示文摘印的 Genomic 是引起依赖于 parent-of-origin 的特定的基因的 monoallelic 表示的 epigenetic 现象。Arabidopsis 基因 PHERES1 印要求 FERTILIZATION 独立种子(FIS ) Polycomb 组建筑群以及包含一个双人脚踏车三元组重复序列的一个远侧地定位的 methylated 区域的功能。在这研究,我们调查了靠近的 PHERES1 相当或相同的事物 PHERES2 的规定。我们发现 PHERES2 也是 FIS Polycomb 组建筑群的直接目标基因,,但是,与 PHERES1 相对照, PHERES2 同等地从母亲、父亲的等位基因被表示。因此, PHERES2 没被印的 genomic 调整,与在 PHERES2 的双人脚踏车重复的缺乏相关。从 PHERES1 地点消除双人脚踏车重复废除印的 PHERES1,证明双人脚踏车重复为印的 PHERES1 是必要的。一起拿这些结果,我们最近复制的基因 PHERES1 和 PHERES2 两个都是 FIS Polycomb 的目标基因的学习表演组织建筑群但是仅仅 PHERES1 被印的 genomic 调整,它是可能的在 PHERES1 地点的最近由重复序列的存在引起了。Corina Belle R. Villar Aleksandra Erilova Grigory Makarevich Raphael Trosch Claudia Kohler 2009Molecular Plant2009,2,4:6
11Partially covered vs uncovered sphincterotome and postendoscopic sphincterotomy bleeding显示文摘AIM: To prospectively compare partially covered vs uncovered sphincterotome use on post-endoscopic biliary sphincterotomy (ES) hemorrhage and other complications. METHODS: All patients referred for therapeutic endoscopic retrograde cholangiopancreatography (ERCP) were randomly assigned to undergo ES either with a partially covered or an uncovered sphincterotome. Both patient and technical risk factors contributing to the development of post-ES bleeding were recorded and analyzed. The characteristics of bleeding was recorded during and after ES. Other complications were also compared. RESULTS: Three-hundred and eighty-seven patients were recruited in this study; 194 patients underwent ES with a partially covered sphincterotome and 193 with conventional uncovered sphincterotome. No statistical difference was noted in the baseline characteristics and risk factors for post-ES induced hemorrhage between the 2 groups. No significant difference in the incidence and pattern of visible bleeding rates was found between the 2 groups (immediate bleeding in 24 patients with the partially covered sphincterotome vs 19 patients with the uncovered sphincterotome, P = 0.418). Delayed bleeding was observed in 2 patients with a partially covered sphincterotome and in 1 patient with an uncovered sphincterotome (P = 0.62). No statistical difference was noted in the rate of other complications. CONCLUSION: The partially covered sphincterotome was not associated with a lower frequency of bleeding. Also, there was no difference in the incidence of other significant complications between the 2 types of sphincterotome.Panagiotis Katsinelos George Paroutoglou Jannis Kountouras Grigoris Chatzimavroudis Christos Zavos Sotiris Terzoudis Taxiarchis Katsinelos Kostas Fasoulas George Gelas George Tzovaras Ioannis Pilpilidis 2010World Journal of Gastroenterology2010,16,40:5
12Recent advances in pharmacological treatment of irritable bowel syndrome显示文摘Irritable bowel syndrome(IBS) is a highly prevalent functional disorder that reduces patients' quality of life. It is a chronic disorder characterized by abdominal pain or discomfort associated with disordered defecation in the absence of identifiable structural or biochemical abnormalities. IBS imposes a significant economic burden to the healthcare system. Alteration in neurohumoral mechanisms and psychological factors, bacterial overgrowth, genetic factors, gut motility, visceral hypersensitivity, and immune system factors are currently believed to influence the pathogenesis of IBS. It is possible that there is an interaction of one or more of these etiologic factors leading to heterogeneous symptoms of IBS. IBS treatment is predicated upon the patient's most bothersome symptoms. Despite the wide range of medications and the high prevalence of the disease, to date no completely effective remedy is available. This article reviews the literature from January 2008 to July 2013 on the subject of IBS peripherally acting pharmacological treatment. Drugs are categorized according to their administration for IBS-C, IBS-D or abdominal pain predominant IBS.Georgia Lazaraki Grigoris Chatzimavroudis Panagiotis Katsinelos 2014World Journal of Gastroenterology2014,20,27:5
13Cecal lipoma with pseudomalignant features: A case report and review of the literature显示文摘Colonic lipoma is a well-documented benign neoplasia, endoscopically appearing as a smooth round yellowish polyp with a thick stalk or broad-based attachment. We describe a 63-year old woman with persistent abdominal pain, in whom colonoscopy revealed a cecal mass with malignant features. Based on the colonoscopy findings, right hemicolectomy was laparoscopically performed for a presumptive diagnosis of a cecal adenocarcinoma, but histological examination revealed a colonic lipoma with overlying mucosal ulceration.Panagiotis Katsinelos Grigoris Chatzimavroudis Christos Zavos Ioannis Pilpilidis Georgia Lazaraki Basilis Papaziogas George Paroutoglou Jannis Kountouras Dimitris Paikos 2007World Journal of Gastroenterology2007,13,17:5
14Endoclipping treatment of life-threatening rectal bleeding after prostate biopsy显示文摘Rectal bleeding is frequently seen in patients undergoing transrectal ultrasound(TRUS)-guided multiple biopsy of the prostate,but is usually mild and stops spontaneously.We report what is believed to be the first case of life-threatening rectal bleeding following this procedure,which was successfully treated by endoscopic intervention through placement of three clips on the sites of bleeding.This case emphasizes endoscopic intervention associated with endoclipping as a safe and effective method to achieve hemostasis in massive rectal bleeding after prostate biopsy.Additionally,current data on the complications of the TRUS-guided multiple biopsy of the prostate and the options for treating fulminant rectal bleeding, a consequence of this procedure,are described.Panagiotis Katsinelos Jannis Kountouras Georgios Dimitriadis Grigoris Chatzimavroudis Christos Zavos Ioannis Pilpilidis George Paroutoglou George Germanidis Kostas Mimidis 2009World Journal of Gastroenterology2009,15,9:4
15A Finite Difference Scheme on a Priori Adapted Meshes for a Singularly Perturbed Parabolic Convection-Diffusion Equation显示文摘A boundary value problem is considered for a singularly perturbed parabolic convection-diffusion equation;we construct a finite difference scheme on a priori (se-quentially) adapted meshes and study its convergence.The scheme on a priori adapted meshes is constructed using a majorant function for the singular component of the discrete solution,which allows us to find a priori a subdomain where the computed solution requires a further improvement.This subdomain is defined by the perturbation parameterε,the step-size of a uniform mesh in x,and also by the required accuracy of the discrete solution and the prescribed number of refinement iterations K for im- proving the solution.To solve the discrete problems aimed at the improvement of the solution,we use uniform meshes on the subdomains.The error of the numerical so- lution depends weakly on the parameterε.The scheme converges almostε-uniformly, precisely,under the condition N^(-1)=o(ε~v),where N denotes the number of nodes in the spatial mesh,and the value v=v(K) can be chosen arbitrarily small for suitable K.Grigory I.Shishkin 2008Numerical Mathematics(Theory,Methods and Applications)2008,1,2:4
16Pancreatic adenocarcinoma:Outstanding problems显示文摘Pancreatic adenocarcinoma remains the fourth leading cause of cancer-related death and is one of the most aggressive malignant tumors with an overall 5-year survival rate of less than 4%.Surgical resection remains the only potentially curative treatment but is only possible for 15%-20% of patients with pancreatic adenocarcinoma.About 40% of patients have locally advanced nonresectable disease.In the past,determination of pancreatic cancer resectability was made at surgical exploration.The development of modern imaging techniques has allowed preoperative staging of patients.Institutions disagree about the criteria used to classify patients.Vascular invasion in pancreatic cancers plays a very important role in determining treatment and prognosis.There is no evidence-based consensus on the optimal preoperative imaging assessment of patients with suspected pancreatic cancer and a unified definition ofborderline resectable pancreatic cancer is also lacking.Thus,there is much room for improvement in all aspects of treatment for pancreatic cancer.Multi-detector computed tomography has been widely accepted as the imaging technique of choice for diagnosing and staging pancreatic cancer.With improved surgical techniques and advanced perioperative management,vascular resection and reconstruction are performed more frequently;patients thought once to be unresectable are undergoing radical surgery.However,when attempting heroic surgery,a realistic approach concerning the patient's age and health status,probability of recovery after surgery,perioperative morbidity and mortality and life quality after tumor resection is necessary.Olga P Zakharova Grigory G Karmazanovsky Viacheslav I Egorov 2012World Journal of Gastrointestinal Surgery2012,4,5:4
17Wireless capsule endoscopy in detecting small-intestinal polyps in familial adenomatous polyposis显示文摘AIM:To detect the prevalence of small bowel polyps by wireless capsule endoscopy(WCE)in patients with familial adenomatous polyposis(FAP).METHODS:We examined prospectively 14 patients with FAP to assess the location,size and number of small-intestinal polyps.Patients'age,sex,years of observation after surgery,type of surgery,duodenal polyps and colorectal cancer at surgery were analyzed.RESULTS:During WCE,polyps were detected in 9/14(64.3%)patients.Duodenal adenomatous polyps were found in nine(64.3%)patients,and jejunal and ileal polyps in seven(50%)and eight(57.1%),respectively.The Spigelman stage of duodenal polyposis was associated with the presence of jejunal and ileal polyps.Identification of the ampulla of Vater was not achieved with WCE.Importantly,the findings of WCE had no immediate impact on the further clinical management of FAP patients.No procedure-related complications were observed in the patients.CONCLUSION:WCE is a promising noninvasive new method for the detection of small-intestinal polyps.Further investigation is required to determine which phenotype of FAP is needed for surveillance with WCE.Panagiotis Katsinelos Jannis Kountouras Grigoris Chatzimavroudis Christos Zavos Ioannis Pilpilidis Kostas Fasoulas George Paroutoglou 2009World Journal of Gastroenterology2009,15,48:3
18Value of two-phase dynamic multidetector computed tomography in differential diagnosis of post-inflammatory strictures from esophageal cancer显示文摘AIM: To characterize the computed tomography(CT) findings in patients with post-inflammatory esophageal strictures(corrosive and peptic) and reveal the optimal scanning phase protocols for distinguishing postinflammatory esophageal stricture and esophageal cancer.METHODS: Sixty-five patients with esophageal strictures of different etiology were included in this study: 24 patients with 27 histopathologically confirmed corrosive strictures, 10 patients with 12 peptic strictures and 31 patients with esophageal cancer were evaluated with a two-phase dynamic contrast-enhanced MDCT. Arterial and venous phases at 10 and 35 s after the attenuation of 200 HU were obtained at the descending aorta, with a delayed phase at 6-8 min after the start of injection of contrast media. For qualitative analysis, CT scans of benign strictures were reviewed for the presence/absence of the following features: 'target sign', luminal mass, homogeneity of contrast medium uptake, concentric wall thickening, conically shapedsuprastenotic dilatation, smooth boundaries of stenosis and smooth mucous membrane at the transition to stenosis, which were compared with a control group of 31 patients who had esophageal cancer. The quantitative analysis included densitometric parameter acquisition using regions-of-interest measurement of the zone of stenosis and normal esophageal wall and the difference between those measurements(ΔCT) at all phases of bolus contrast enhancement. Esophageal wall thickening, length of esophageal wall thickening and size of the regional lymph nodes were also evaluated. RESULTS: The presence of a concentric esophageal wall, conically shaped suprastenotic dilatation, smooth upper and lower boundaries, 'target sign' and smooth mucous membrane at the transition to stenosis were suggestive of a benign cause, with sensitivities of 92.31%, 87.17%, 94.87%, 76.92% and 82.05%, respectively, and specificities of 70.96%, 89.66%, 80.65%, 96.77% and 93.55%, respectively. The features that were most suggestive of a malignant cause were eccentric esophageal wall thickening, tuberous upper and lower boundaries of stenosis, absence of mucous membrane visualization, rupture of the mucous membrane at the upper boundary of stenosis, cup-shaped suprastenotic dilatation, luminal mass and enlarged regional lymph nodes with specificities of 92.31% 94.87%, 67.86%, 100%, 97.44%, 94.87% and 82.86%, respectively and sensitivities of 70.97%, 80.65%, 96.77%, 80.65%, 54.84%, 87.10% and 60%, respectively. The highest tumor attenuation occurred in the arterial phase(mean attenuation 74.13 ± 17.42 HU), and the mean attenuation difference between the tumor and the normal esophageal wall(mean ΔCT) in the arterial phase was 23.86 ± 19.31 HU. Here, 11.5 HU of ΔCT in the arterial phase was the cut-off value used to differentiate esophageal cancer from post-inflammatory stricture(P = 0.000). The highest attenuation of postinflammatory strictures occurred in the delayed phase(mean attenuation 71.66 ± 14.28 HU), and the mean ΔCT in delayed phase was 34.03 ± 15.94 HU. Here, 18.5 HU of ΔCT in delayed phase was the cut-off value used to differentiate post-inflammatory stricture from esophageal cancer(P < 0.0001).CONCLUSION: The described imaging findings reveal high diagnostic significance in the differentiation of benign strictures from esophageal cancer.Grigory G Karmazanovsky Svetlana A Buryakina Evgeny V Kondratiev Qin Yang Dmitry V Ruchkin Dmitry V Kalinin 2015World Journal of Gastroenterology2015,21,29:3
19A comparative study of 10-Fr vs. 7-Fr straight plastic stents in the treatment of postcholecystectomy bile leak显示文摘Panagiotis Katsinelos Jannis Kountouras George Paroutoglou Grigoris Chatzimavroudis George Germanidis Christos Zavos Ioannis Pilpilidis Dimitris Paikos Basilis Papaziogas 2008Surgical Endoscopy2008,,1:3
20Dynamic failure of dry and fully saturated limestone samples based on incubation time concept显示文摘This paper outlines the results of experimental study of the dynamic rock failure based on the comparison of dry and saturated limestone samples obtained during the dynamic compression and split tests. The tests were performed using the Kolsky method and its modifications for dynamic splitting. The mechanical data(e.g. strength, time and energy characteristics) of this material at high strain rates are obtained. It is shown that these characteristics are sensitive to the strain rate. A unified interpretation of these rate effects, based on the structuraletemporal approach, is hereby presented. It is demonstrated that the temporal dependence of the dynamic compressive and split tensile strengths of dry and saturated limestone samples can be predicted by the incubation time criterion. Previously discovered possibilities to optimize(minimize) the energy input for the failure process is discussed in connection with industrial rock failure processes. It is shown that the optimal energy input value associated with critical load, which is required to initialize failure in the rock media, strongly depends on the incubation time and the impact duration. The optimal load shapes, which minimize the momentum for a single failure impact, are demonstrated. Through this investigation, a possible approach to reduce the specific energy required for rock cutting by means of high-frequency vibrations is also discussed.Yuri V. Petrov Ivan V. Smirnov Grigory A. Volkov Andrei K. Abramian Anatoliy M. Bragov Stanislav N. Verichev 2017Journal of Rock Mechanics and Geotechnical Engineering2017,9,1:3
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