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Navigating Market Choices: Understanding Carrot Market Outlet Selection among Smallholder Farmers in Kenya
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作者 Hillary Kiprotich Ngeno Ngenoh Evans +1 位作者 Oscar Ayuya Ingasia Hillary K. Bett 《Agricultural Sciences》 2024年第6期676-703,共28页
This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the fact... This research delves into the hurdles and strategies aimed at augmenting the market involvement of smallholder carrot farmers in Nakuru County, Kenya. Employing a Multinomial Logit (MNL) model, it scrutinizes the factors influencing the selection of marketing outlets among carrot farmers. The findings unveil that a significant majority (81%) of surveyed farmers actively participate in diverse market outlets, encompassing the farm gate, cleaning point, local market, external market, and export market. Notably, pivotal buyers include aggregators, brokers, wholesalers, retailers, and consumers, with transactions predominantly occurring at the farm level. Additionally, the analysis discerns substantial influences of socio-economic characteristics, experiential factors, and geographical proximity on farmers’ choices of market outlets. Specifically, gender, age, land size, farming experience, and distance to markets emerge as critical determinants. Moreover, the study delves into the examination of market margins along the carrot value chain, shedding light on the potential profitability of carrot farming in the region. Remarkably, higher average gross margins are identified in export and external markets, signaling lucrative prospects for farmers targeting these segments. However, disparities in profit distribution between farmers and traders underscore the necessity for interventions to ensure equitable value distribution throughout the value chain. These findings underscore the imperative for tailored interventions to tackle challenges and foster inclusive agricultural development. Strategies such as farmer organizations, contracting, and vertical integration are advocated to enhance market access and profitability for smallholder carrot farmers. Thus, this study enriches our comprehension of the dynamics within carrot value chains and provides valuable insights for policymakers and development practitioners aiming to uplift rural livelihoods and bolster food security. 展开更多
关键词 Market outlet Selection Smallholder Farmers Multinomial Logit Model Determinants Carrot Value Chain
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Primary gastroduodenal tuberculosis presenting as gastric outlet obstruction:A case report and review of literature 被引量:7
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作者 Abdihamid Mohamed Ali Yahye Garad Mohamed +4 位作者 Abdirahman Ahmed Mohamud Abdulkadir Nor Mohamed Mohamed Rage Ahmed Ismail Mohamud Abdullahi Tuba Saydam 《World Journal of Clinical Cases》 SCIE 2024年第8期1536-1543,共8页
BACKGROUND Mycobacterium tuberculosis(TB)is the causative agent of TB,a chronic granulo-matous illness.This disease is prevalent in low-income countries,posing a significant global health challenge.Gastrointestinal TB... BACKGROUND Mycobacterium tuberculosis(TB)is the causative agent of TB,a chronic granulo-matous illness.This disease is prevalent in low-income countries,posing a significant global health challenge.Gastrointestinal TB is one of the three forms.The disease can mimic other intra-abdominal conditions,leading to delayed diagnosis owing to the absence of specific symptoms.While gastric outlet obs-truction(GOO)remains a frequent complication,its incidence has declined with the advent of proton pump inhibitors and Helicobacter pylori eradication therapy.Gastroduodenal TB can cause upper gastrointestinal hemorrhage,obstruction,and malignancy-like tumors.CASE SUMMARY A 23-year-old male presented with recurrent epigastric pain,distension,nausea,vomiting,and weight loss,prompting a referral to a gastroenterologist clinic.Endoscopic examination revealed distorted gastric mucosa and signs of chronic inflammation.However,treatment was interrupted,possibly owing to vomiting or comorbidities such as human immunodeficiency virus infection or diabetes.Subsequent surgical intervention revealed a dilated stomach and diffuse thickening of the duodenal wall.Resection revealed gastric wall effacement with TB.CONCLUSION Primary gastric TB is rare,frequently leading to GOO.Given its rarity,suspicions should be promptly raised when encountering relevant symptoms,often requiring surgical intervention for diagnosis and treatment. 展开更多
关键词 TUBERCULOSIS Gastrointestinal tuberculosis Gastric outlet obstruction Gastroduodenal tuberculosis Case report
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Endoscopic ultrasound guided-gastroenterostomy is the best choice in the treatment of gastric outlet obstruction
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作者 Mateusz Jagielski 《World Journal of Gastrointestinal Endoscopy》 2024年第12期691-693,共3页
First of all,I would like to congratulate Vilas-Boas et al on an interesting publication.In this letter the authors write about very interesting topics in the management of patients with malignant gastric outlet obstr... First of all,I would like to congratulate Vilas-Boas et al on an interesting publication.In this letter the authors write about very interesting topics in the management of patients with malignant gastric outlet obstruction(GOO).GOO developed in up to 20%of patients with advanced hepatopancreatobiliary disease both in benign and malignant form.For this reason,the issue is very current.I fully agree with Vilas-Boas et al that technical aspect of the procedures(surgeon’s view)often differs from the patient’s view(regarding such factors as cancerrelated survival,overall survival,body mass composition,nutritional biomarkers,chemotherapy tolerance and patient-reported quality of life).The mentioned factors should be taken into account when interpreting the effectiveness of treatment modalities for malignant GOO(mGOO),which should be also considered in the future studies in this subject.In my opinion,all above mentioned factors could be summarized in one term:“Improving quality of life of patients with mGOO”. 展开更多
关键词 Gastric outlet obstruction GASTROENTEROSTOMY Endoscopic ultrasound Endoscopic stenting Pancraetic cancer ENDOSCOPY
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Treatment of choice for malignant gastric outlet obstruction: More than clearing the road
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作者 Li Jiang Xiao-Ping Chen 《World Journal of Gastrointestinal Endoscopy》 2024年第11期587-594,共8页
In this editorial,we comment on the in-press article in the World Journal of Gas-trointestinal Endoscopy concerning the treatment of malignant gastric outlet obstruction(mGOO).The original theory of treatment involves... In this editorial,we comment on the in-press article in the World Journal of Gas-trointestinal Endoscopy concerning the treatment of malignant gastric outlet obstruction(mGOO).The original theory of treatment involves bypassing the obstruction or reenabling the patency of the passage.Conventional surgical gastroenterostomy provides long-term relief of symptoms in selected patients,with substantial morbidity and a considerable rate of delayed gastric emptying.Endoscopic stenting was introduced as an alternative minimally invasive proce-dure with less procedural morbidity and rapid clinical improvement;however,it presented a high rate of long-term recurrence.Therefore,challenges remain in the treatment of mGOO patients to improve clinical outcomes.Endoscopic ultra-sound-guided gastroenterostomy has recently emerged as a promising method because of the combined effects of surgery and endoscopy,whereas stomach-partitioning gastrojejunostomy has been reported as a modified surgical proce-dure to reduce the rate of delayed gastric emptying.In decision-making regarding the treatment of choice,it should be taken into account that mGOO might be accompanied by a variety of pathological conditions,including cancer cachexia,anorexia,malabsorption,and etc.,all of which can also lead to the characteristic symptoms and poor nutritional status of mGOO.The treatment plan should consider comprehensive aspects of patients to achieve practical improve-ments in prognosis and the quality of life. 展开更多
关键词 Malignant gastric outlet obstruction Surgical gastroenterostomy Endoscopic stenting Endoscopic ultrasound-guided gastroenterostomy Stomach-partitioning gastrojejunostomy Anorexia‒cachexia syndrome
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Editor-in-Chief articles of choice and comments from January to June 2024
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作者 Andrzej S Tarnawski 《World Journal of Gastroenterology》 SCIE CAS 2024年第34期3875-3882,共8页
As the Editor-in-Chief of the World Journal of Gastroenterology,I carefully review all articles every week before a new issue’s online publication,including the title,clinical and research importance,originality,nove... As the Editor-in-Chief of the World Journal of Gastroenterology,I carefully review all articles every week before a new issue’s online publication,including the title,clinical and research importance,originality,novelty,and ratings by the peer reviewers.Based on this review,I select the papers of choice and suggest pertinent changes(e.g.,in the title or text)to the company editors responsible for publication.This process,while time-consuming,is essential for assuring the quality of publications and highlighting important articles that readers may revisit. 展开更多
关键词 Papers of choice Weekly review Suggested changes/revisions Hepatocellular carcinoma Pancreatic cancer Liver cirrhosis Liver injury Gastric cancer Colorectal cancer Inflammatory bowel diseases
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Editor-in-Chief articles of choice and comments at the year-end of 2023
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作者 Andrzej S Tarnawski 《World Journal of Gastroenterology》 SCIE CAS 2024年第1期1-8,共8页
As the Editor-in-Chief of World Journal of Gastroenterology,every week prior to a new issue’s online publication,I perform a careful review of all encompassed articles,including the title,clinical and/or research imp... As the Editor-in-Chief of World Journal of Gastroenterology,every week prior to a new issue’s online publication,I perform a careful review of all encompassed articles,including the title,clinical and/or research importance,originality,novelty,and ratings by the peer reviewers.Based on this review,I select the papers of choice and suggest pertinent changes(e.g.,in the title)to the Company Editors responsible for publication.This process,while time-consuming,is very important for assuring the quality of publications and highlighting important articles that Readers may revisit. 展开更多
关键词 Papers of choice Careful weekly review Suggested changes/revisions Hepatocellular carcinoma Pancreatic cancer Liver cirrhosis Liver injury Gastric cancer Colorectal cancer Inflammatory bowel diseases
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The Influence of Social Media on College Choice among Undergraduates Majoring in Big Data Management and Application in China:Taking Guilin University of Electronic Technology as an Example
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作者 Junchao Dong Joan P.Lazaro 《Journal of Contemporary Educational Research》 2024年第10期128-138,共11页
This study aims to investigate the influence of social media on college choice among undergraduates majoring in Big Data Management and Application in China.The study attempts to reveal how information on social media... This study aims to investigate the influence of social media on college choice among undergraduates majoring in Big Data Management and Application in China.The study attempts to reveal how information on social media platforms such as Weibo,WeChat,and Zhihu influences the cognition and choice process of prospective students.By employing an online quantitative survey questionnaire,data were collected from the 2022 and 2023 classes of new students majoring in Big Data Management and Application at Guilin University of Electronic Technology.The aim was to evaluate the role of social media in their college choice process and understand the features and information that most attract prospective students.Social media has become a key factor influencing the college choice decision-making of undergraduates majoring in Big Data Management and Application in China.Students tend to obtain school information through social media platforms and use this information as an important reference in their decision-making process.Higher education institutions should strengthen their social media information dissemination,providing accurate,timely,and attractive information.It is also necessary to ensure effective management of social media platforms,maintain a positive reputation for the school on social media,and increase the interest and trust of prospective students.Simultaneously,educational decision-makers should consider incorporating social media analysis into their recruitment strategies to better attract new student enrollment.This study provides a new perspective for understanding higher education choice behavior in the digital age,particularly by revealing the importance of social media in the educational decision-making process.This has important practical and theoretical implications for higher education institutions,policymakers,and social media platform operators. 展开更多
关键词 Social media Big Data Management and Application Undergraduate college choice Student decision-making behavior Chinese higher education
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Influence of land use characteristics and trip attributes on commuting mode choice: a case of Nanjing 被引量:5
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作者 刘志伟 邓卫 季彦婕 《Journal of Southeast University(English Edition)》 EI CAS 2014年第1期107-112,共6页
The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit (NL) model. Based on the random utility maximum theory, the NL model is form... The effects of socio-demographics, land use characteristics and trip attributes on the commute mode choice are studied with a nested logit (NL) model. Based on the random utility maximum theory, the NL model is formulated. The analysis is carried out in the main area of Nanjing. Direct and cross elasticities are calculated to analyze the effects of travel time and travel cost on the selection of travel mode choice. The results reveal that the non-motorized travel modes are more attractive in the areas with higher housing and employment accessibility and car owners are found to be more likely to commute to work by car. The bus and subway choice probabilities are more sensitive to changes in travel times than to changes in travel costs. In conclusion, a comprehensive public transit system and effective integration of land use and transportation policies help to relieve the traffic congestion levels caused by the increasing urban sprawl. 展开更多
关键词 traffic engineering land use travel mode choice nested logit model elasticity analysis
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Test Research on the Characteristics of Pollution Boundary Layer in the River Outlet Area of Grand Liao River 被引量:1
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作者 张云海 杨洪斌 邹旭东 《Meteorological and Environmental Research》 CAS 2010年第6期57-61,共5页
By using the meteorological data in the pollution boundary layer which was observed in two ground observation sites:coast and land in the river outlet area of Grand Liao River during January-February in 2007,the daily... By using the meteorological data in the pollution boundary layer which was observed in two ground observation sites:coast and land in the river outlet area of Grand Liao River during January-February in 2007,the daily change characteristics of pollute boundary layer in winter in the area were discussed. The results showed that the pollute boundary layer in the river outlet area of Grand Liao River was affected by the sea and land. In the certain weather condition,maybe the sea-land breeze appeared in the low altitude which was below 200 m in the coastal zone. The stability change in the different height in the coastal zone was more stable than in the land zone,and the wind field change in the area was mainly in 300 m low altitude. At night,the temperature inversion often appears in the area,and the thickness of temperature inversion layer is stably during 200-300 m. The thermal internal boundary layer penetrated deeply into the land about 10 km,and the height could reach 800 m. The atmospheric diffusion ability in the coastal area was weaker and stronger in the land area. 展开更多
关键词 River outlet of Liao River Pollution characteristics Boundary layer Atmospheric diffusion Test research China
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An empirical study on travel demand management modeling based on discrete choice method 被引量:3
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作者 陆振波 王树盛 《Journal of Southeast University(English Edition)》 EI CAS 2012年第1期106-111,共6页
In view of the problem that the requirements of travel demand management and traffic policy-sensitivity are ignored during the establishment process of the travel demand forecasting model, a discrete-choice-based trav... In view of the problem that the requirements of travel demand management and traffic policy-sensitivity are ignored during the establishment process of the travel demand forecasting model, a discrete-choice-based travel demand forecasting model is proposed to demonstrate its applicability to travel demand management. A car-bus discrete choice model is established, including three variables, i. e,, individual socioeconomic characteristics, time, and cost, and the traffic policy-sensitivity is evaluated through two kinds of traffic policies: parking charges and bus priorities. The empirical results show that travel choice is insensitive to the policy of parking charges as 88. 41% of the travelers are insensitive to parking charges; travel choice is, however, sensitive to the policy of bus priorities as 67.70% of the car travelers and 77.02% of the bus travelers are sensitive to bus priorities. The discrete-choice-based travel demand forecasting model is quite policy-sensitive and also has a good adaptability for travel demand management when meeting the basic functions of the demand forecasting model. 展开更多
关键词 discrete choice travel demand forecasting traveldemand management logit model
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Plights and Outlet:Environmental Problem Analysis of Agricultural Eco-tourism 被引量:2
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作者 廖军华 《Journal of Landscape Research》 2011年第2期84-87,共4页
As agricultural eco-tourism development played a vital role in promoting rural economic and social development and constructing new harmonious countryside,the paper had analyzed environmental problem produced during i... As agricultural eco-tourism development played a vital role in promoting rural economic and social development and constructing new harmonious countryside,the paper had analyzed environmental problem produced during its development,pointed out that blind development of agricultural eco-tourism had seriously destroyed resources and ecological environment and that tourist infrastructure construction and urbanization had ruined rural unique natural landscape.In view of current situation of environment,it also studied reasons causing environmental disruption,which lied in insufficient guidance and support of government,deficient scientific development planning and management system,and poor environmental consciousness of tourist operators and tourists.On this basis,it summarized that agricultural eco-tourism development should follow principles of sustainable development,synchronization between development and protection,and coordination between tourism development and environmental protection.It concluded proper ways to develop agricultural eco-tourism,and emphasized that it should draw up scientific and reasonable development planning,enhance government's macro-administration,establish and perfect ecological compensation mechanism,and strive to cultivate people's environmental awareness. 展开更多
关键词 AGRICULTURAL ECO-TOURISM ENVIRONMENTAL PROBLEMS Analysis Plights outletS
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Routes Choice of Urban Agriculture,Ecotourism and Cultural Innovation Industry Fusion
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作者 朱启酒 钱静 《Agricultural Science & Technology》 CAS 2012年第12期2667-2670,共4页
The fusion of urban agriculture, ecotourism and cultural innovation industry has been a necessary way for industry updating, value increase and income im- provement of farmers in suburbs. The methods available of the ... The fusion of urban agriculture, ecotourism and cultural innovation industry has been a necessary way for industry updating, value increase and income im- provement of farmers in suburbs. The methods available of the fusion are as fol- lows: corporation development and operation, led by government with an integrated plan; corporation management and development under guidance of market with sup- port from government; collective development under guidance of market and policies; individual development and operation with the model of "villagers participation de- pending on infrastructure provided by government". The four routes enjoy exclusive advantages and characters. Hence, different villages and towns should adopt the most suitable one according to local conditions for further development and management. 展开更多
关键词 choice of route Industry fusion Culture innovation ECOTOURISM Urbanagriculture
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澳洲坚果主导品种Own Choice的品种配置研究
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作者 孔广红 陶丽 +3 位作者 贺熙勇 倪书邦 陈丽兰 肖晓明 《中国南方果树》 北大核心 2024年第5期74-79,共6页
为了明确澳洲坚果园主导品种Own Choice(O.C)的最适配置品种,选择HAES863、D、D4、HAES816、HAES906、HAES294、HAES900、A4等8个品种为O.C授粉,统计分析不同授粉处理的着果率、杂交不亲和性程度指数、着果花序率、每果序着果数、落果... 为了明确澳洲坚果园主导品种Own Choice(O.C)的最适配置品种,选择HAES863、D、D4、HAES816、HAES906、HAES294、HAES900、A4等8个品种为O.C授粉,统计分析不同授粉处理的着果率、杂交不亲和性程度指数、着果花序率、每果序着果数、落果率、壳果横径等指标。结果表明,以着果率及着果花序率统计的杂交不亲和性程度指数发现,HAES863、D、D4、HAES816、HAES906与O.C的杂交亲和性高于A4、HAES294、HAES900。供试品种处理的着果率与着果花序率之间存在正相关关系,初步推断可使用着果花序率代替着果率评价O.C与不同品种的杂交不亲和性程度;8个授粉处理的平均着果花序率为40.60%,可以此推断O.C与不同授粉品种的田间杂交不亲和性程度。综合分析推断,澳洲坚果主导品种O.C的最适配置品种为HAES863和D4,根据小气候可选择性搭配种植D、HAES906、HAES816。 展开更多
关键词 澳洲坚果 Own choice 授粉品种 着果率 着果花序率 杂交不亲和性
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Learning and learning choice in the nematode Caenorhabditis elegans 被引量:1
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作者 叶华跃 叶波平 王大勇 《Neuroscience Bulletin》 SCIE CAS CSCD 2006年第6期355-360,共6页
The nematode Caenorhabditis elegans is an attractive model organism to study the behavioral plasticity for its simple system and ability to respond to diverse environmental stimuli, such as touch, smell, taste and tem... The nematode Caenorhabditis elegans is an attractive model organism to study the behavioral plasticity for its simple system and ability to respond to diverse environmental stimuli, such as touch, smell, taste and temperature. Learning in C. elegans encompasses both non-associative learning and associative learning. Till now, themotaxis and chemotaxis are two major paradigms for associative learning and there are at least 6 forms of chemotaxis-mediated associative learning. Three research systems have also been explored to study the mechanism of learning choice in worms. This review will discuss the forms, research models, genetic and molecular regulation of learning and learning choice in C. elegans. 展开更多
关键词 LEARNING learning choice Caenorhabditis elegans
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On developing multiple-choice and the washback-Taking cloze as an example
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作者 曾燕虹 《英语广场(学术研究)》 2014年第2期70-73,共4页
There are several types of cloze. The MC cloze is widely used in national examinations. MC cloze is similar to multiple choice, but not exactly the same. To develop an MC cloze, a suitable passage should be chosen fir... There are several types of cloze. The MC cloze is widely used in national examinations. MC cloze is similar to multiple choice, but not exactly the same. To develop an MC cloze, a suitable passage should be chosen first, then some of the words should be deleted, and finally the distractors for each item are set. To test whether the cloze is validable and reliable, the students are asked to take a pretest. The results are analyzed by GITEST. The data demonstrates that the difficulty level and the discrimination are not good enough. Some of the distractors are too tricky while some others are too weakly distractive. 展开更多
关键词 CLOZE multiple-choice DESIGN washback
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Procedure for prolapse and hemorrhoids vs traditional surgery for outlet obstructive constipation 被引量:57
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作者 Ming Lu Bo Yang +2 位作者 Yang Liu Qing Liu Hao Wen 《World Journal of Gastroenterology》 SCIE CAS 2015年第26期8178-8183,共6页
AIM: To compare the clinical efficacies of two surgical procedures for hemorrhoid rectal prolapse with outlet obstruction-induced constipation.METHODS: One hundred eight inpatients who underwent surgery for outlet obs... AIM: To compare the clinical efficacies of two surgical procedures for hemorrhoid rectal prolapse with outlet obstruction-induced constipation.METHODS: One hundred eight inpatients who underwent surgery for outlet obstructive constipation caused by internal rectal prolapse and circumferential hemorrhoids at the First Affiliated Hospital of Xinjiang Medical University from June 2012 to June 2013 were prospectively included in the study.The patients with rectal prolapse hemorrhoids with outlet obstructioninduced constipation were randomly divided into two groups to undergo either a procedure for prolapse and hemorrhoids(PPH)(n = 54) or conventional surgery(n = 54; control group).Short-term(operative time,postoperative hospital stay,postoperative urinary retention,postoperative perianal edema,and postoperative pain) and long-term(postoperative anal stenosis,postoperative sensory anal incontinence,postoperative recurrence,and postoperative difficulty in defecation) clinical effects were compared between the two groups.The short- and long-term efficacies of the two procedures were determined.RESULTS: In terms of short-term clinical effects,operative time and postoperative hospital stay were significantly shorter in the PPH group than in the control group(24.36 ± 5.16 min vs 44.27 ± 6.57 min,2.1 ± 1.4 d vs 3.6 ± 2.3 d,both P < 0.01).The incidence of postoperative urinary retention was higher in the PPH group than in the control group,but the difference was not statistically significant(48.15% vs 37.04%).Theincidence of perianal edema was significantly lower in the PPH group(11.11% vs 42.60%,P < 0.05).The visual analogue scale scores at 24 h after surgery,first defecation,and one week after surgery were significantly lower in the PPH group(2.9 ± 0.9 vs 8.3 ± 1.1,2.0 ± 0.5 vs 6.5 ± 0.8,and 1.7 ± 0.5 vs 5.0 ± 0.7,respectively,all P < 0.01).With regard to long-term clinical effects,the incidence of anal stenosis was lower in the PPH group than in the control group,but the difference was not significant(1.85% vs 5.56%).The incidence of sensory anal incontinence was significantly lower in the PPH group(3.70% vs 12.96%,P < 0.05).The incidences of recurrent internal rectal prolapse and difficulty in defecation were lower in the PPH group than in the control group,but the differences were not significant(11.11% vs 16.67% and 12.96% vs 24.07%,respectively).CONCLUSION: PPH is superior to the traditional surgery in the management of outlet obstructive constipation caused by internal rectal prolapse with circumferential hemorrhoids. 展开更多
关键词 Internal RECTAL PROLAPSE outlet obstructiveconstipation Procedure for PROLAPSE and HEMORRHOIDS PROSPECTIVE STUDY Randomized controlled STUDY
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Logit-based exit choice model of evacuation in rooms with internal obstacles and multiple exits 被引量:12
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作者 郭仁拥 黄海军 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第3期101-107,共7页
A logit-based discrete choice model is proposed to study the exit choice behaviour of evacuees in rooms with internal obstacles and multiple exits. Several factors influencing the exit choice behaviour, including the ... A logit-based discrete choice model is proposed to study the exit choice behaviour of evacuees in rooms with internal obstacles and multiple exits. Several factors influencing the exit choice behaviour, including the information obtained by evacuees, the tendency of following others, the visibility and familiarity of exits and the physical conditions of nearby exits, are considered. Evacuees are allowed to re-select their target exits for minimizing the perceived disutility during evacuation process. Numerical results from applying the model to cellular automata simulation of evacuation are presented and the effects of some model parameters on evacuation time are investigated. 展开更多
关键词 exit choice EVACUATION logit-based discrete choice cellular automata
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Numerical Prediction and Performance Experiment in a Deep-well Centrifugal Pump with Different Impeller Outlet Width 被引量:20
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作者 SHI Weidong ZHOU Ling +2 位作者 LU Weigang PEI Bing LANG Tao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第1期46-52,共7页
The existing research of the deep-well centrifugal pump mainly focuses on reduce the manufacturing cost and improve the pump performance, and how to combine above two aspects together is the most difficult and importa... The existing research of the deep-well centrifugal pump mainly focuses on reduce the manufacturing cost and improve the pump performance, and how to combine above two aspects together is the most difficult and important topic. In this study, the performances of the deep-well centrifugal pump with four different impeller outlet widths are studied by the numerical, theoretical and experimental methods in this paper. Two stages deep-well centrifugal pump equipped with different impellers are simulated employing the commercial CFD software to solve the Navier-Stokes equations for three-dimensional incompressible steady flow. The sensitivity analyses of the grid size and turbulence model have been performed to improve numerical accuracy. The flow field distributions are acquired and compared under the design operating conditions, including the static pressure, turbulence kinetic energy and velocity. The prototype is manufactured and tested to certify the numerical predicted performance. The numerical results of pump performance are higher than the test results, but their change trends have an acceptable agreement with each other. The performance results indicted that the oversize impeller outlet width leads to poor pump performances and increasing shaft power. Changing the performance of deep-well centrifugal pump by alter impeller outlet width is practicable and convenient, which is worth popularizing in the engineering application. The proposed research enhances the theoretical basis of pump design to improve the performance and reduce the manufacturing cost of deep-well centrifugal pump. 展开更多
关键词 deep-well centrifugal pump impeller outlet width performance numerical simulation
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Is there a correlation between the outcome of transurethral resection of prostate and preoperative degree of bladder outlet obstruction? 被引量:10
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作者 Mi Mi Oh Jin Wook Kim +1 位作者 Je long Kim Du Geon Moon 《Asian Journal of Andrology》 SCIE CAS CSCD 2012年第4期556-559,共4页
To compare the impact of transurethral resection of prostate (TURP) on symptom scores and maximal flow rates (Qmax) in patients with equivocal bladder outlet obstruction (BOO) and definite BOO and to assess the ... To compare the impact of transurethral resection of prostate (TURP) on symptom scores and maximal flow rates (Qmax) in patients with equivocal bladder outlet obstruction (BOO) and definite BOO and to assess the relationship between the surgical outcomes and degree of preoperative BOO, we prospectively evaluated men with lower urinary tract symptoms and bladder outlet obstruction index (BOO1) greater than 20, who were refractory to conventional medical treatment and underwent TURP. Urodynamic evaluation, International Prostate Symptom Score (IPSS), uroflowmetry, post-void residual volume (PVR) check and transrectal ultrasound were performed. 20〈B001〈40 was defined as equivocal BOO and BOO1 〉~40 as definite BOO. Changes of IPSS, Qmax, PVR and correlation analysis was performed between the degree of improvement of Qmax, subdomains of I PSS and BOO1. Fifty-four patients showed equivocal BOO and 80 patients showed definite BOO. Preoperatively equivocal BOO group and definite BOO group showed significant differences in maximal bladder capacity and prevalence of detrusor overactivity, whereas no difference was noted in prostate volume. Postoperatively both groups showed improvements in Qmax, obstructive (IPSSO) and irritative (IPSSI) subdomain of IPSS, but the degree of improvement in Qmax and IPSSI subdomain was statistically significantly greater in definite BOO group. The degree of improvement of Qmax and IPSSI showed weak correlation with preoperative BOO1. As a weak correlation was identified between preoperative degree of BOO and outcome of TURP, other factors other than BOO1 such as severity of patients' symptoms should be considered in deciding treatment modality. 展开更多
关键词 bladder outlet obstruction bladder outlet obstruction index International Prostate Symptom Scores
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Self-expandable metal stents for malignant gastric outlet obstruction: A pooled analysis of prospective literature 被引量:6
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作者 Emo E van Halsema Erik AJ Rauws +1 位作者 Paul Fockens Jeanin E van Hooft 《World Journal of Gastroenterology》 SCIE CAS 2015年第43期12468-12481,共14页
AIM: To provide an overview of the clinical outcomes of self-expandable metal stent(SEMS) placement for malignant gastric outlet obstruction(MGOO).METHODS: A systematic literature search was performed in Pub Med of th... AIM: To provide an overview of the clinical outcomes of self-expandable metal stent(SEMS) placement for malignant gastric outlet obstruction(MGOO).METHODS: A systematic literature search was performed in Pub Med of the literature published between January 2009 and March 2015. Only prospective studies that reported on the clinical success of stent placement for MGOO were included. The primary endpoint was clinical success,defined according to the definition used in the original article. Data were pooled and analyzed using descriptive statistics. Subgroup analyses were performed for partially covered SEMSs(PCSEMSs) and uncovered SEMSs(UCSEMSs) using Fisher's exact test.RESULTS: A total of 19 studies,including 1281 patients,were included in the final analysis. Gastric(42%) and pancreatic(37%) cancer were the main causes of MGOO. UCSEMSs were used in 76% of patients and PCSEMSs in 24%. The overall pooled technical success rate was 97.3% and the clinical success rate was 85.7%. Stent dysfunction occurred in 19.6% of patients,mainly caused by re-obstruction(12.6%) and stent migration(4.3%),and was comparable between PCSEMSs and UCSEMSs(21.2% vs 19.1%,respectively,P = 0.412). Re-obstruction was more common with UCSEMSs(14.9% vs 5.1%,P < 0.001) and stent migration was more frequent after PCSEMS placement(10.9% vs 2.2%,P < 0.001). The overall perforation rate was 1.2%. Bleeding was reported in 4.1% of patients,including major bleeding in 0.8%. The median stent patency ranged from 68 to 307 d in five studies. The median overall survival ranged from 49 to 183 d in 13 studies.CONCLUSION: The clinical outcomes in this large population showed that enteral stent placement was feasible,effective and safe. Therefore,stent placement is a valid treatment option for the palliation of MGOO. 展开更多
关键词 STENTS Gastric outlet OBSTRUCTION STOMACH NEOPLASM
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