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Selection of overburden surface mining method in West Virginia by analytical hierarchy process 被引量:5
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作者 Timothy A.Nolan Vladislav Kecojevic 《International Journal of Coal Science & Technology》 EI CAS 2014年第3期306-314,共9页
The broad objective of this research was to improve current surface mining practices and reduce negative environmental impact of overburden removal in West Virginia(WV).The specific objectives were to(i)compare conven... The broad objective of this research was to improve current surface mining practices and reduce negative environmental impact of overburden removal in West Virginia(WV).The specific objectives were to(i)compare conventional surface mining method(drilling,blasting,digging,and loading)to a surface miner(SM)method,and(ii)apply the analytical hierarchy process(AHP)to help select the optimal mining method based on production,cost and environmental criteria.The design and the procedures used in this research involve five interrelated modules:(i)rock properties of overburden in WV,(ii)drilling and blasting,(iii)digging and loading,(iv)SM method,and(v)comparative analysis and selection of the optimal mining method by AHP.Results of this research indicate that application of SM method would yield higher cost of overburden removal than conventional mining methods in rocks with a high unconfined compressive strength and abrasivity.A significant advantage of SM method,where applicable,is the elimination of the negative environmental impacts associated with blasting. 展开更多
关键词 Surface mining West Virginia OVERBURDEN Production rate COST Environmental impact AHP model
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An Analysis of Farming in the Rural Economic Development of West Virginia
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作者 Saima Bashir Janaranjana Herath Tesfa Gebremedhin 《Journal of Agricultural Science and Technology(B)》 2012年第7期848-855,共8页
Farming is still an important sector in rural economic development of West Virginia where 44% of the population lives in rural areas and 24% of the land is used for farming. While income earnings, education and employ... Farming is still an important sector in rural economic development of West Virginia where 44% of the population lives in rural areas and 24% of the land is used for farming. While income earnings, education and employment rates are low in rural areas, poverty rates and unemployment are high compared to the urban areas. Thus, in the context of rural development farming is a potential major economic sector where 42% of the people's primary occupation is reported as farming. The objective of this study is to identify and estimate the potential impacts of farm employment in rural economic growth of West Virginia. Data from U.S. Bureau of Labor Statistics and U.S Census Bureau for the period of 1993 to 2008 are used for the empirical analysis. A model derived from the three simultaneous equations of Duncan is used for analysis. Three-Stage Least Squares (3SLS) method using the statistical package of STATA is used for estimation. The results concerning simultaneous relationships with population density growth, per capita income growth, and farm employment growth reveal significant importance of farming in rural economic development of West Virginia. Furthermore, the results indicate the positive impacts of population density, number of people with farming as principal occupation, and crop production on rural farming sector. 展开更多
关键词 FARMING rural economic development simultaneous equation 3SLS ANALYSIS West Virginia.
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Assessing stand structure in successional stages of dark coniferous forests in western Sichuan, China 被引量:1
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作者 Jiangming Ma Shirong Liu +1 位作者 Zuomin Shi Jingxin Wang 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第4期779-786,共8页
Subalpine dark coniferous forests in the western Sichuan Province of China play an important role in the hydrological processes in the upper reaches of the Yangtze River. Second-growth forests, with different stand su... Subalpine dark coniferous forests in the western Sichuan Province of China play an important role in the hydrological processes in the upper reaches of the Yangtze River. Second-growth forests, with different stand successional stages, have developed as a result of logging over the past 50 years. Forest cover and stand structure changed greatly with concomitant degradation of forest ecosystem functions. To understand how the stand structures of the second-growth forests change during the stand succession process, we analyzed stand structure characteristics and an old-growth state index of the bamboo and moss-forest types. We found that stand structure at the young successional stage featured one-third of the structure characteristics of the old-growth dark coniferous forests,while the structure of the medium-aged stage had reached half the structure of the old-growth state. The two forest types were similar in the rate of development at the young successional stage but differed at the medium-aged stage;the moss-forest type had more advanced development than the bamboo-forest type at the medium-aged successional stage. 展开更多
关键词 stand forests bamboo leaved ecosystem logging young Yangtze succession shrub
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L-Arginine Levels among Hypertensive Patients in Sokoto, North Western Nigeria
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作者 O. Erhabor A. B. Ibrahim +12 位作者 Y. Abdulrahaman A. H. Chiroma M. Imoru F. P. Udomah M. Ahmed K. Ibrahin H. Buhari A. Okwesili O. Onuigwe H. M. Liman K. Van Dyke N. B. Egenti I. P. Iwueke 《Open Journal of Blood Diseases》 2017年第1期1-15,共15页
Hypertension is a major public health problem that adversely affects the health status of individuals, families and communities. L-arginine levels of a total of 90 consecutively-recruited hypertensive subjects and 50 ... Hypertension is a major public health problem that adversely affects the health status of individuals, families and communities. L-arginine levels of a total of 90 consecutively-recruited hypertensive subjects and 50 age-matched non-hypertensive controls were studied. Plasma from subjects and control participants were analyzed for L-arginine. The mean values of L-arginine level were significantly lower among the hypertensive subjects which are (174.33 ± 78.31 μmol/L) compared to those of the 50 non-hypertensive controls (237.82 ± 261.16 μmol/L) (p = 0.04). There was no statistically significant difference in the L-arginine levels of hypertensive subjects based on gender, age and ethnici-ty (p = 0.87, 0.23 and 0.57) respectively. The L-arginine level was significantly higher among married hypertensive subjects (181.71 ± 78.17 μmol/L) compared to single or unmarried subjects (130.62 ± 65.99 μmol/L) (p = 0.03). The mean value of L-arginine level was significantly higher among hypertensive subjects with mild blood pressure (187.63 ± 77.93 μmol/L) compared to those with high blood pressure (156.93 ± 76.31 μmol/L). The difference however was not statistically significant (p = 0.05). The findings from this study confirm that the level of L-arginine is lower among hypertensive subjects compared to non-hypertensive controls. Age, gender and ethnicity did not have a significant effect on the L-arginine levels of hypertensive subjects. L-arginine level was significantly lower among single hypertensive patients and those with markedly raised blood pressure. It is recommended the L-arginine supplement be prescribed to hypertensive patient as a prophylactic measure. There is a need to enlighten hypertensive patients in the area on the need to maintain a balanced diet containing sufficient level of L-arginine. 展开更多
关键词 L-ARGININE HYPERTENSIVE Patients Sokoto NIGERIA
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护理专业国际学生短期访学教育项目的设计与实施
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作者 Ubolrat Piamjariyakul Saima Shafique +4 位作者 Dana L.Friend Kimberly A.Adams Wiyakarn Sanghuachang Trisha M.Petitte Stephanie Young 《International Journal of Nursing Sciences》 CSCD 2024年第1期83-90,共8页
目的旨在描述制定及评估一项短期留学生研究和教育项目。方法研究分为项目制定与实施及评价2部分。根据1名国际学生的短期访学需求,护理学院的全球护理项目协调员和首席导师共同确定项目基本内容和团队成员。该项目学习活动考虑了该国... 目的旨在描述制定及评估一项短期留学生研究和教育项目。方法研究分为项目制定与实施及评价2部分。根据1名国际学生的短期访学需求,护理学院的全球护理项目协调员和首席导师共同确定项目基本内容和团队成员。该项目学习活动考虑了该国际学生对老年人和居家临终关怀的兴趣,包括4项内容:.开展研究工作,参与教学活动,参与临床实践活动,以及特殊活动和专业发展培训课程。在为期6个月的访学结束时,对参与此次教学活动的教师、研究生及留学生进行访谈和简短问卷调查。结果通过访谈了解到3个方面的内容:通过参与该项目中获得的经验(增强了教育和研究的多样性,获得了新的全球医疗保健知识,对文化意识的自我反思和促进);项目实施的障碍和挑战(签证申请过程,英语语言障碍,缺乏公共交通设施,时间安排冲突);克服这些障碍和挑战的策略(在课程中增加文化多样性信息;与其他同学一起学习英语;使用不同的沟通技巧;在签证申请过程中与大学全球事务办公室持续合作;提供互动体验)。所有项目参与者都对该项目表示非常满意(4.67±0.50),认为对他们在科研、教学和临床实践方面的护理技能有很大影响(4.67±0.50)。结论此次项目的参与者均获得了相关经验,可用于今后的教学指导活动。国际护理专业学生需要得到帮助才能更好地适应访学环境,教师必须具有文化敏感性,了解学生的学习需求,并倡导营造适合学生学习的环境。 展开更多
关键词 评价 国际学生 护理教育 课程
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eQUEST Based Building Energy Modeling Analysis for Energy Efficiency of Buildings
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作者 Saroj Lamichhane Roseline Mostafa +1 位作者 Bhaskaran Gopalakrishnan Dayakar G.Devaru 《Energy Engineering》 EI 2024年第10期2743-2767,共25页
Building energy performance is a function of numerous building parameters.In this study,sensitivity analysis on twenty parameters is performed to determine the top three parameters that have the most significant impac... Building energy performance is a function of numerous building parameters.In this study,sensitivity analysis on twenty parameters is performed to determine the top three parameters that have the most significant impact on the energy performance of buildings.Actual data from two fully operational commercial buildings were collected and used to develop a building energy model in the Quick Energy Simulation Tool(eQUEST).The model is calibrated using the Normalized Mean Bias Error(NMBE)and Coefficient of Variation of Root Mean Square Error(CV(RMSE))method.The model satisfies the NMBE and CV(RMSE)criteria set by the American Society of Heating,Refrigeration,and Air-Conditioning(ASHRAE)Guideline 14,Federal Energy Management Program(FEMP),and International Performance Measurement and Verification Protocol(IPMVP)for building energy model calibration.The values of the parameters are varied in two levels,and then the percentage change in output is calculated.Fractional factorial analysis on eight parameters with the highest percentage change in energy performance is performed at two levels in a statistical software JMP.For building A,the top 3 parameters from the percentage change method are:Heating setpoint,cooling setpoint and server room.From fractional factorial design,the top 3 parameters are:heating setpoint(p-value=0.00129),cooling setpoint(p-value=0.00133),and setback control(p-value=0.00317).For building B,the top 3 parameters from both methods are:Server room(pvalue=0.0000),heating setpoint(p-value=0.00014),and cooling setpoint(p-value=0.00035).If the best values for all top three parameters are taken simultaneously,energy efficiency improves by 29%for building A and 35%for building B. 展开更多
关键词 Energy efficiency EQUEST energy consumption building energy modeling
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Condition indices for rigid pavements: A comparative analysis of state DOTs using Michigan PMS data
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作者 Rahul Raj Singh Mumtahin Hasnat +3 位作者 Muhammed Emin Kutay Syed Waqar Haider James Bryce Bora Cetin 《Journal of Road Engineering》 2024年第3期348-360,共13页
Pavement infrastructure is vital in providing services and links between various sectors of society. Therefore, thepreservation and maintenance of these roads are critical to attaining a pavement network in good condi... Pavement infrastructure is vital in providing services and links between various sectors of society. Therefore, thepreservation and maintenance of these roads are critical to attaining a pavement network in good conditionthroughout its service life. Various performance indicators like the international roughness index (IRI), pavementcondition index (PCI), and present serviceability rating (PSR) have been used by the state department of transportation (DOT) and highway agencies for evaluating pavement surface conditions and planning future maintenance strategies. Limited data availability, multiple distresses depending on region, lack of correlation of thesecondition indices to maintenance strategies, and data collection limitations pose a challenge for applying theseindices to local conditions. This paper compares condition indices of different states for rigid pavements. Further,using a specific condition index for local conditions is also highlighted. For this purpose, five states and theircorresponding condition indices were evaluated and compared to the Michigan DOT distress index (DI). Thesestates include Virginia, Minnesota, North Dakota, Louisiana, and Oregon. The corresponding distresses of eachcondition index were converted to make them compatible with the MDOT DI. This study used the MDOT'spavement management system (PMS) database to evaluate each condition index for 433 rigid pavement sections.Each distress index was plotted against MDOT DI and compared using a paired t-test. Results show that thecondition indices of Virginia and Minnesota are comparable to DI in terms of the Spearman correlation value. Thet-test results show that except for Virgina, condition indices from other states statistically differ from DI.Therefore, one can't use those directly for local conditions in Michigan. This paper presents the evaluation anddata requirements for each condition index and its impact on selecting a maintenance treatment. 展开更多
关键词 Rigid pavement Pavement management Condition index Distress index
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Implementation of Fuzzy Logic Control into an Equivalent Minimization Strategy for Adaptive Energy Management of A Parallel Hybrid Electric Vehicle
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作者 Jared A. Diethorn Andrew C. Nix +1 位作者 Mario G. Perhinschi W. Scott Wayne 《Journal of Transportation Technologies》 2024年第1期88-118,共31页
As government agencies continue to tighten emissions regulations due to the continued increase in greenhouse gas production, automotive industries are seeking to produce increasingly efficient vehicle technology. Hybr... As government agencies continue to tighten emissions regulations due to the continued increase in greenhouse gas production, automotive industries are seeking to produce increasingly efficient vehicle technology. Hybrid electric vehicles (HEVs) have been introduced to mitigate problems while improving fuel economy. HEVs have led to the demand of creating more advanced controls software to consider multiple components for propulsive power in a vehicle. A large section in the software development process is the implementation of an optimal energy management strategy meant to improve the overall fuel efficiency of the vehicle. Optimal strategies can be implemented when driving conditions are known a prior. The Equivalent Consumption Minimization Strategy (ECMS) is an optimal control strategy that uses an equivalence factor to equate electrical to mechanical power when performing torque split determination between the internal combustion engine and electric motor for propulsive and regenerative torque. This equivalence factor is determined from offline vehicle simulations using a sensitivity analysis to provide optimal fuel economy results while maintaining predetermined high voltage battery state of charge (SOC) constraints. When the control hierarchy is modified or different driving styles are applied, the analysis must be redone to update the equivalence factor. The goal of this work is to implement a fuzzy logic controller that dynamically updates the equivalence factor to improve fuel economy, maintain a strict charge sustaining window of operation for the high voltage battery, and reduce computational time required during algorithm development. The adaptive algorithm is validated against global optimum fuel economy and charge sustaining results from a sensitivity analysis performed for multiple drive cycles. Results show a maximum fuel economy improvement of 9.82% when using a mild driving style and a 95% success rate when maintaining an ending SOC within 5% of the desired SOC regardless of starting SOC. 展开更多
关键词 Hybrid Electric Vehicle Fuzzy Logic Adaptive Control Charge Sustainability
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Impact of index admission cholecystectomy vs interval cholecystectomy on readmission rate in acute cholangitis: National Readmission Database survey
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作者 Abdullah Sohail Ahmed Shehadah +4 位作者 Ammad Chaudhary Khadija Naseem Amna Iqbal Ahmad Khan Shailendra Singh 《World Journal of Gastrointestinal Endoscopy》 2024年第6期350-360,共11页
BACKGROUND Elective cholecystectomy(CCY)is recommended for patients with gallstone-related acute cholangitis(AC)following endoscopic decompression to prevent recurrent biliary events.However,the optimal timing and imp... BACKGROUND Elective cholecystectomy(CCY)is recommended for patients with gallstone-related acute cholangitis(AC)following endoscopic decompression to prevent recurrent biliary events.However,the optimal timing and implications of CCY remain unclear.AIM To examine the impact of same-admission CCY compared to interval CCY on patients with gallstone-related AC using the National Readmission Database(NRD).METHODS We queried the NRD to identify all gallstone-related AC hospitalizations in adult patients with and without the same admission CCY between 2016 and 2020.Our primary outcome was all-cause 30-d readmission rates,and secondary outcomes included in-hospital mortality,length of stay(LOS),and hospitalization cost.RESULTS Among the 124964 gallstone-related AC hospitalizations,only 14.67%underwent the same admission CCY.The all-cause 30-d readmissions in the same admission CCY group were almost half that of the non-CCY group(5.56%vs 11.50%).Patients in the same admission CCY group had a longer mean LOS and higher hospitalization costs attrib-utable to surgery.Although the most common reason for readmission was sepsis in both groups,the second most common reason was AC in the interval CCY group.CONCLUSION Our study suggests that patients with gallstone-related AC who do not undergo the same admission CCY have twice the risk of readmission compared to those who undergo CCY during the same admission.These readmis-sions can potentially be prevented by performing same-admission CCY in appropriate patients,which may reduce subsequent hospitalization costs secondary to readmissions. 展开更多
关键词 Acute cholangitis Gallstone-related complications National Readmission Database 30-d readmission rates Resource utilization In-hospital mortality
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The Axiology of Consciousness in Mocombeian Consciousness Field Theory
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作者 Paul C.Mocombe 《Philosophy Study》 2024年第4期168-185,共18页
This work explores the axiology of consciousness in Mocombe’s consciousness field in the material world.The paper critically assesses Mocombe’s consciousness field theory(CFT)within the larger body of contemporary o... This work explores the axiology of consciousness in Mocombe’s consciousness field in the material world.The paper critically assesses Mocombe’s consciousness field theory(CFT)within the larger body of contemporary ontological debates regarding the nature,origin,and constitution of consciousness in the universe.The work goes on to highlight the manifestation of Mocombe’s consciousness field in the material resource framework that is the earth,and the nature and origins of ethics and values. 展开更多
关键词 structuration theory phenomenological structuralism structure/agency mythopraxis quantum mechanics social class language game Haitian epistemology Haitian/Vilokan idealism consciousness field theory
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The Black American Church: A Reactionary and Ideological Apparatus of Slavery
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作者 Paul C.Mocombe 《Philosophy Study》 2024年第1期30-41,共12页
This work argues that Denmark Vesey,Nat Turner,Gabriel Prosser,David Walker,Henry Highland Garnet,amongst a few others were the reactionary(dialectical)exceptions to the black church,not the norm,an(ideological)instit... This work argues that Denmark Vesey,Nat Turner,Gabriel Prosser,David Walker,Henry Highland Garnet,amongst a few others were the reactionary(dialectical)exceptions to the black church,not the norm,an(ideological)institution established to interpellate and indoctrinate blacks to accept their conditions in slavery.In other words,the aforementioned were the enslaved who used Christian dogma to(negative dialectically)respond to the barbarity of slavery by violently convicting white Christian society for not living up to its values,ideas,and ideals given the treatment of African people by so-called Christians.In the latter sense it was reactionary;in the former,it was an ideological apparatus of domination and control for the institution of slavery.The contemporary attempt to racially vindicate the black church as a sui generis revolutionary institution overflowing with Africanisms is ahistorical and ideological reaped in pseudoscientific propositions stemming from postmodern and post-structural theories. 展开更多
关键词 Black Church African-Americanization racial identity religiosity black diaspora SPIRITUALISM phenomenological structuralism
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Spontaneous Tumor Lysis Syndrome Secondary to Iatrogenic Acute Kidney Injury: A Case Report
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作者 Joseph Capito Mitchell Hoyson +2 位作者 Amie M. Ashcraft Hassan Suleiman Courtney S. Pilkerton 《Case Reports in Clinical Medicine》 2024年第5期155-161,共7页
Spontaneous Tumor Lysis Syndrome (STLS) is a rare oncologic condition caused by the breakdown of neoplastic tissue in the absence of traditional anti-tumor therapy. It is postulated that cancers with rapidly dividing ... Spontaneous Tumor Lysis Syndrome (STLS) is a rare oncologic condition caused by the breakdown of neoplastic tissue in the absence of traditional anti-tumor therapy. It is postulated that cancers with rapidly dividing cells lead to increased cell turnover which exceeds the kidneys’ ability to adequately filtrate by-products of cellular breakdown (i.e., phosphate, potassium, anduric acid), leading to end organ damage. It has been reported in the past that kidney failure is a sequelae of Tumor Lysis Syndrome (TLS), but there have been no reports that demonstrate acute kidney injury (AKI) preceding TLS. The case presented here demonstrates TLS in a patient with no formal cancer diagnosis, who had received no chemotherapy or radiation that was precipitated by an iatrogenic AKI with chlorthalidone and ibuprofen. This unusual pattern of AKI preceding STLS may provide insight into the pathophysiology of the condition and could possibly lead to greater understanding of this phenomenon. 展开更多
关键词 Spontaneous Tumor Lysis Acute Kidney Injury LYMPHOMA CHLORTHALIDONE NSAID
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Impact of frailty on endoscopic retrograde cholangiopancreatography outcomes in nonagenarians:A United States national experience
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作者 Sanket Dhirubhai Basida Dushyant Singh Dahiya +11 位作者 Muhammad Nadeem Yousaf Brinda Basida Bhanu Siva Mohan Pinnam Manesh Kumar Gangwani Hassam Ali Sahib Singh Yash R Shah Daksh Ahluwalia Mihir Prakash Shah Saurabh Chandan Neil R Sharma Shyam Thakkar 《World Journal of Gastrointestinal Endoscopy》 2024年第3期148-156,共9页
BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an essential therapeutic tool for biliary and pancreatic diseases.Frail and elderly patients,especially those aged≥90 years are generally considered a... BACKGROUND Endoscopic retrograde cholangiopancreatography(ERCP)is an essential therapeutic tool for biliary and pancreatic diseases.Frail and elderly patients,especially those aged≥90 years are generally considered a higher-risk population for ERCP-related complications.AIM To investigate outcomes of ERCP in the Non-agenarian population(≥90 years)concerning Frailty.METHODS This is a cohort study using the 2018-2020 National Readmission Database.Patients aged≥90 were identified who underwent ERCP,using the international classification of diseases-10 code with clinical modification.Johns Hopkins’s adjusted clinical groups frailty indicator was used to classify patients as frail and non-frail.The primary outcome was mortality,and the secondary outcomes were morbidity and the 30 d readmission rate related to ERCP.We used univariate and multivariate regression models for analysis.RESULTS A total of 9448 patients were admitted for any indications of ERCP.Frail and non-frail patients were 3445(36.46%)and 6003(63.53%)respectively.Indications for ERCP were Choledocholithiasis(74.84%),Biliary pancreatitis(9.19%),Pancreatico-biliary cancer(7.6%),Biliary stricture(4.84%),and Cholangitis(1.51%).Mortality rates were higher in frail group[adjusted odds ratio(aOR)=1.68,P=0.02].The Intra-procedural complications were insigni-ficant between the two groups which included bleeding(aOR=0.72,P=0.67),accidental punctures/lacerations(aOR=0.77,P=0.5),and mechanical ventilation rates(aOR=1.19,P=0.6).Post-ERCP complication rate was similar for bleeding(aOR=0.72,P=0.41)and post-ERCP pancreatitis(aOR=1.4,P=0.44).Frail patients had a longer length of stay(6.7 d vs 5.5 d)and higher mean total charges of hospitalization($78807 vs$71392)compared to controls(P<0.001).The 30 d all-cause readmission rates between frail and non-frail patients were similar(P=0.96).CONCLUSION There was a significantly higher mortality risk and healthcare burden amongst nonagenarian frail patients undergoing ERCP compared to non-frail.Larger studies are warranted to investigate and mitigate modifiable risk factors. 展开更多
关键词 Endoscopic retrograde cholangiopancreatography NONAGENARIANS FRAILTY MORTALITY Healthcare burden
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两种烟煤的液化及液化油的组成特征研究 被引量:26
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作者 朱继升 Lawrence P.Norcio +6 位作者 Edwin L.Kugler Dady B.Dadyburjor YANG Jian-li LIU Zhen-yu 杨建丽 刘振宇 钟炳 《燃料化学学报》 EI CAS CSCD 北大核心 2001年第3期214-218,共5页
在 40 0℃、30min、7MPa冷氢压条件下两种煤液化结果表明 ,兖州煤比DECS 6 (美国煤 )煤更容易液化或共液化 ,这可能与兖州煤硫含量比较高有关 ,但DECS 6煤的油收率要高于兖州煤 ,表明EDCS 6煤容易裂解生成小分子化合物。同种煤液化油的... 在 40 0℃、30min、7MPa冷氢压条件下两种煤液化结果表明 ,兖州煤比DECS 6 (美国煤 )煤更容易液化或共液化 ,这可能与兖州煤硫含量比较高有关 ,但DECS 6煤的油收率要高于兖州煤 ,表明EDCS 6煤容易裂解生成小分子化合物。同种煤液化油的沸点分布特征基本一致。UV(紫外光谱 )特征表明 ,液化油中单环芳烃主要为烷基取代苯类化合物 ,二环芳烃组分主要是烷基取代萘类化合物 ,三环芳烃主要为渺位缩合的菲类化合物 ,四环芳烃主要为芘、屈艹 类化合物 ,五环芳烃以苯并芘类化合物为主 ,而极性化合物可归属为含O、S。 展开更多
关键词 液化 沸点分布 族组成 烟煤 液化油
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咯利普兰对H_2O_2致PC12细胞氧化应激损伤的保护作用 被引量:7
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作者 卓烨烨 林焕冰 +2 位作者 周恒 张汉霆 徐江平 《中国药理学通报》 CAS CSCD 北大核心 2010年第11期1429-1435,共7页
目的探讨PDE4抑制剂咯利普兰(rolipram)对H2O2致PC12细胞氧化应激损伤的保护作用及其作用机制。方法以H2O2损伤PC12细胞为氧化应激损伤模型,MTT法检测细胞存活率;碘化丙啶(Propidium iodide,PI)染色流式细胞术检测细胞周期变化;化学比... 目的探讨PDE4抑制剂咯利普兰(rolipram)对H2O2致PC12细胞氧化应激损伤的保护作用及其作用机制。方法以H2O2损伤PC12细胞为氧化应激损伤模型,MTT法检测细胞存活率;碘化丙啶(Propidium iodide,PI)染色流式细胞术检测细胞周期变化;化学比色法测定细胞清除羟自由基(·OH)和超氧阴离子自由基(O2·)的能力;以及培养上清液中的丙二醛(MDA)、谷胱甘肽(GSH)和一氧化氮(NO)含量、超氧化物歧化酶(SOD)活性。Western blot和Real-time RT-PCR检测细胞内硫氧还蛋白(Trx)和诱导型一氧化氮合酶(iNOS)的表达。结果咯利普兰能明显提高H2O2损伤的PC12细胞存活率,恢复细胞增殖;提高细胞清除·OH和O2·的能力;降低MDA和NO含量,提高GSH含量和SOD活性;使Trx蛋白和mRNA表达增加,同时下调iNOS蛋白和mRNA表达。结论咯利普兰对H2O2致PC12细胞损伤具有保护作用,其作用机制可能与提高PC12细胞的抗氧化能力相关。 展开更多
关键词 咯利普兰 氧化应激 PC12细胞 cAMP应答元件结合蛋白 活性氧簇 硫氧还蛋白 诱导型一氧化氮合酶
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磷酸二酯酶抑制剂与学习记忆相关信号转导通路研究进展 被引量:8
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作者 王闯 程玉芳 +1 位作者 张汉霆 徐江平 《中国药理学通报》 CAS CSCD 北大核心 2009年第7期844-847,共4页
大量的研究表明,环磷酸腺苷反应元件结合蛋白(cAMP response element binding protein,CREB)直接或间接激活相关基因转录,进而表达c-fos、c-jun、BDNF等,在神经元应激损伤后的再生、存活及修复以及学习记忆等方面发挥重要作用。磷酸二... 大量的研究表明,环磷酸腺苷反应元件结合蛋白(cAMP response element binding protein,CREB)直接或间接激活相关基因转录,进而表达c-fos、c-jun、BDNF等,在神经元应激损伤后的再生、存活及修复以及学习记忆等方面发挥重要作用。磷酸二酯酶可以水解环磷酸腺苷(cyclic AMP,cAMP)及环磷酸鸟苷(cyclic GMP,cGMP),进而影响其下游信号转导,发挥对CREB的调节作用。该文从磷酸二酯酶抑制剂与学习记忆相关信号通路的关系及在学习记忆障碍中发挥的作用予以综述,并由该通路入手对发现治疗神经退行性变疾病药物作用新靶点的可能性予以展望。 展开更多
关键词 CAMP CGMP 信号转导通路 学习记忆 神经退行性变疾病 靶点
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氧化应激与阿尔采末病 被引量:9
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作者 卓烨烨 张汉霆 徐江平 《中国药理学通报》 CAS CSCD 北大核心 2010年第4期435-437,共3页
阿尔采末病(Alzheimer’s disease,AD)是一种以进行性认知功能障碍和记忆力损害为主的中枢神经系统退行性疾病。对AD的发病机制存在多种假说,其中氧化应激假说目前越来越受到重视。该文从自由基来源、AD病理特征与氧化应激的关系、相关... 阿尔采末病(Alzheimer’s disease,AD)是一种以进行性认知功能障碍和记忆力损害为主的中枢神经系统退行性疾病。对AD的发病机制存在多种假说,其中氧化应激假说目前越来越受到重视。该文从自由基来源、AD病理特征与氧化应激的关系、相关的动物和临床相关研究、常用抗氧化剂和磷酸二酯酶抑制剂在抗氧化应激方面对AD的治疗作用等,对近年来国内外氧化应激与AD关系的研究进行简要综述。 展开更多
关键词 阿尔采末病 氧化应激 发病机制 神经元 自由基 抗氧化剂 磷酸二酯酶抑制剂
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利用T_1加权DCE-MRI技术对脑胶质瘤分级 被引量:9
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作者 邓振生 张娜 +3 位作者 孟莉 王小宜 廖伟华 HOU BL 《中国生物医学工程学报》 CAS CSCD 北大核心 2010年第1期16-21,共6页
应用T1加权动态对比度增强磁共振成像(DCE-MRI)技术对脑胶质瘤进行术前分级,验证其用于脑胶质瘤分级的准确性和可重复性。对26例脑胶质瘤患者团注Gd-DTPA对比剂后,以1.5TSiemens Syngo MRI扫描仪采集DCE T1加权图像。首先基于改进的Toft... 应用T1加权动态对比度增强磁共振成像(DCE-MRI)技术对脑胶质瘤进行术前分级,验证其用于脑胶质瘤分级的准确性和可重复性。对26例脑胶质瘤患者团注Gd-DTPA对比剂后,以1.5TSiemens Syngo MRI扫描仪采集DCE T1加权图像。首先基于改进的Tofts两室药物动力学模型,从采集到的动态组图像建立病灶区感兴趣区内的平均信号强度-时间曲线,然后应用非线性最小二乘拟合方法对该曲线进行拟合,获取定量参数。这些参数包括:初始增强率ER、回流速率常数Kep、排泄速率常数Kel、曲线下面积AUC、峰值高度PH、到达峰值的时间TTP,最后与临床组织病理学结果进行比较,建立这些定量参数与脑胶质瘤分级之间的定量关系。采用独立样本t检验比较任意两个分级之间各定量参数的统计学差异,P<0.05作为统计学差异标准。ER、AUC和PH随着脑胶质瘤的病理分级由低到高地增加;低级别脑胶质瘤中的Ⅰ与Ⅱ级之间以及高级别中的Ⅲ与Ⅳ级之间的比较结果显示,ER、AUC和PH的值均无明显统计学差异(P>0.05);低级别与高级别级之间的比较结果显示,仅参数ER的差异具有统计学意义(P<0.05)。ER是术前准确界定脑胶质瘤低级别与高级别的最具敏感性和特异性的参数,其界定阈值约为0.68。 展开更多
关键词 定量灌注MRI T1加权DCE 脑胶质瘤 定量药物动力学 非线性最小二乘拟合
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耦合装药特性对深孔预裂爆破应力波能量衰减的影响 被引量:15
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作者 蔡峰 刘泽功 《煤炭学报》 EI CAS CSCD 北大核心 2014年第S2期384-389,共6页
针对利用深孔预裂爆破技术对低透气性煤层进行强化增透过程中爆生应力波能量弱、衰减快、信噪比低的现状,对爆破孔装药结构提出了改进方案,建立了耦合装药对爆破孔孔壁透射波能量和爆炸载荷影响特性的数值计算模型,利用Matlab编程技术... 针对利用深孔预裂爆破技术对低透气性煤层进行强化增透过程中爆生应力波能量弱、衰减快、信噪比低的现状,对爆破孔装药结构提出了改进方案,建立了耦合装药对爆破孔孔壁透射波能量和爆炸载荷影响特性的数值计算模型,利用Matlab编程技术对此数值计算模型进行了计算并获得解析解。在淮南矿业集团顾桥矿进行了爆生应力波能量受耦合装药系数ξ变化的影响特性的现场实验,对基于功率谱的能量分析法进行了改进,并利用此分析法对实验数据进行分析。数值计算和现场实验均表明:随ξ的增大应力波总能量反而减小;当ξ为1.5时,应力波信号在10~50 Hz频段的能量最强,且信噪比也最高。因而在爆破增透实施过程中应将耦合装药系数ξ设计为1.5左右,从而获得最佳的增透半径和增透效果。 展开更多
关键词 耦合装药系数 深孔预裂爆破 应力波 能量衰减
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国内外奥运旅游研究进展综述 被引量:16
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作者 李健 罗芬 邓金阳 《旅游学刊》 CSSCI 北大核心 2007年第9期80-87,共8页
自公元前776年举办第一届古代奥运会以来,旅游与奥运会便形影相随。随着现代人类休闲时间的增多与经济承受力的增强,作为大型事件的奥运会吸引了越来越多的旅游者观光游览,同时也受到旅游学术界越来越多的关注。本文以奥运旅游的起源、... 自公元前776年举办第一届古代奥运会以来,旅游与奥运会便形影相随。随着现代人类休闲时间的增多与经济承受力的增强,作为大型事件的奥运会吸引了越来越多的旅游者观光游览,同时也受到旅游学术界越来越多的关注。本文以奥运旅游的起源、奥运旅游的定义与特点出发,从奥运旅游研究历史、吸引物研究、市场特征研究、经济社会影响研究等多方面对国内外奥运旅游研究进行了总结。 展开更多
关键词 奥林匹克 奥运会 奥运旅游 奥运经济
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