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Metabolic enzymes in seasonally acclimatized and cold acclimated rufous-collared sparrow inhabiting a Chilean Mediterranean environment

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Current Zoology 2014年第3期60卷 338-350页

作者： isaac PenA-VILLALOBOS Monica NUNEZ-VILLEGAS Francisco BOZINOVIC Pablo SABAT Departamento de Ciencias Ecologicas Facultad de Ciencias Universidad de Chile Casilla 653 Santiago Chile Departamento de Ecologia and Center of Applied Ecology & Sustainability (CAPES) Facultad de Ciencias Biol6gicas Pontificia Universidad Cat61ica de Chile Santiago 6513677 Chile

Due to the higher energy requirements of birds during winter, it is predicted that the activities of metabolic enzymes （e.g., citrate synthase, CS and cytochrome C oxidase, COX） should increase in tandem with increases in rates of energy expendi ture （e.g., basal metabolic rate, BMR）. However, there is mixed support for the hypothesis of enzymatic acclimatization. Fur thermore, there is little information about the effect of ambient temperature on energetics and tissue enzyme activity levels in passerines inhabiting seasonal Mediterranean environments. In this study we evaluated the interplay between BMR and enzyme activities of freshly caught individuals of the passerine Zonotrichia capensis in winter and summer in a Mediterranean environment from central Chile, and also in warm （30℃） and cold （15℃） labacclimated birds. The results revealed a lack of seasonal variation in BMR, thermal conductance and in the activity of CS and COX. However, we found higher BMR and lower thermal conductance in coldacclimated than in warmacclimated birds. Also, total CS activity was higher in the flight muscles of coldacclimated than in warmacclimated birds. We found also a significant correlation between BMR and total CS activity in pectoral muscle. Although some authors have suggested that BMR mainly depends on the metabolic intensity and mass of internal organs, our results revealed that skeletal muscles such as the flight muscles may also affect BMR. Finally, differences in the accli mation and acclimatization responses in Rufouscollared sparrows suggest that largescale oscillations in the physical environment might maintain the capacity for flexibility in thermogenic traits through generations .

关键词： Basal metabolic rate Citrate synthase Cytochrome C oxidase Phenotypic flexibility Thermal acclimation,Zonotrichia capensis

Use of testicular sperm in couples with SCSA-defined high sperm DNA fragmentation and failed intracytoplasmic sperm injection using ejaculated sperm

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Asian Journal of Andrology 2020年第4期22卷 348-353页

作者： Mohannad Alharbi Fadl Hamouche Simon Phillips Jacques isaac Kadoch Armand Zini Division of Urology Department of SurgeryMcGill UniversityMontreal H4A3J1Canada Department of Urology College of MedicineQassim UniversityQassim 1162Saudi Arabia OVO Fertility Clinic Montreal H4P2S4Canada Department of Obstetrics and Gynecology University of MontrealMontreal H3C3J7Canada

Sperm DNA fragmentation(SDF)has been linked with male infertility,and previous studies suggest that SDF can have negative influence on pregnancy outcomes with assisted *** performed a retrospective review of consecutive couples with a high SDF level that had intracytoplasmic sperm injection(ICSI)using testicular sperm(T-ICSI).We compared the T-ICSI outcomes to that of two control groups:87 couples with failed first ICSI cycle and who had a second ICSI cycle using ejaculated sperm(Ej-ICSI),and 48 consecutive couples with high sperm chromatin structure assay(SCSA)-defined SDF(>15%)that underwent an ICSI cycle using ejaculated sperm after one or more failed ICSI cycles(Ej-ICSI-high SDF).The mean number of oocytes that were retrieved and the total number of embryos were not different among the three *** mean number of transferred embryos in the T-ICSI group was higher than the Ej-ICSI group but not significantly different than the Ej-ICSI-high SDF group(1.4,1.2,and 1.3,respectively,Pent than the Ej-ICSI and Ej-ICSI-high SDF groups(48.6%,48.2%,and 38.7%,respectively,P>0.05).No significant difference was found in live birth rate when comparing T-ICSI to Ej-ICSI and Ej-ICSI-high SDF *** results suggest that pregnancy outcomes and live birth rates with T-ICSI are not significantly superior to Ej-ICSI in patients with an elevated SCSA-defined sperm DNA fragmentation and prior ICSI failure(s).

关键词： intracytoplasmic sperm injection male infertility sperm chromatin structure assay sperm DNA fragmentation sperm retrieval testicular sperm

The Influencing Factors of Capital Structure and Types of Firm Growth Opportunities:Empirical Analysis from Chinese Listed Firms

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The Influencing Factors of Capital Structure and Types of Fi...

作者： Amusa isaac 中国石油大学(北京)

学位级别：硕士

The relevance of an organization or a firm is mostly dependent on its ability to make a reliable optimal capital structure *** capital structure among other things determines the financing ability of the firm now and in the *** value and cost of a firm have more to do with capital structure *** study has launched into a dimension of firm growth opportunities that deal with the influencing factors of capital structure of the Chinese listed *** data collected and used for this study is from the Chinese Stock Market and Accounting Research(CSMR).CSMR is an all-inclusive catalogue for Chinese corporate study,covering statistics on the Chinese standard market,financial reports,and China commercial supremacy of Chinese registered *** used for the study covered about 3,487 companies from 2006 to 2018.A total of twenty-eight influencing factors were selected for the study but to test their validity and ensure how well they influence the Chinese firms and their growth avenues;a series of analyses were done but in all only nine of them proved to be reliable and valid for the *** dimensions of profitability were realized,cashflow,size,the collateral value of an asset,expense to sale,fixed asset to net worth,and asset turnover,all these represent the explanatory variables in this *** is characterized as the reliant variable in the first fragment of this work,where we attempt to uncover the rapport between leverage and the selected influencing factors of capital *** second part dealt with types of firm growth opportunities,leverage,and the influencing *** analysis,variance inflation factor(VIF),and correlation methods were utilized to investigate connections that may exist among these *** paper aimed at selecting well-proven factors of capital structure that statistically conform to the Chinese business environment,analysed the rapport between growth opportunities and the capital str

关键词： Firm growth opportunities Influencing factors Chinese listed firms Capital structure

Microstructural Characterization and Tensile Behavior of Rutile(TiO_2)-Reinforced AA6063 Aluminum Matrix Composites Prepared by Friction Stir Processing

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Acta Metallurgica Sinica(english Letters) 2019年第1期32卷 52-62页

作者： Sahayam Joyson Abraham isaac Dinaharan Jebaraj David Raja Selvam Esther Titilayo Akinlabi Department of Mechanical engineering V V College of Engineering Department of Mechanical engineering Science University of Johannesburg Auckland Park Kingsway Campus Department of Mechanical engineering Karunya Institute of Technology and Sciences

Rutile(TiO_2) particle-reinforced aluminum matrix composites were prepared by friction stir processing. The microstructure was studied using conventional and advanced characterization techniques. TiO_2 particles were found to be dispersed uniformly in the composite. Clusters of TiO_2 particles were observed at a higher particle content of 18 vol%. The interface between the TiO_2 particle and the aluminum matrix was characterized by the absence of pores and reactive ***-grain boundaries, ultra-fine grains and dislocation density were observed in the composites. TiO_2 particles improved the mechanical properties of the composites. However, a drop in tensile strength was observed at a higher particle content due to cluster formation. All the prepared composites exhibited ductile mode of fracture.

关键词： Aluminum matrix composites Friction stir processing Rutile Microstructure Tensile strength

RecGuard: An efficient privacy preservation blockchain-based system for online social network users

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Blockchain(Research and Applications) 2023年第1期4卷 36-47页

作者： Samuel Akwasi Frimpong Mu Han Edward Kwadwo Boahen Rexford Nii Ayitey Sosu isaac Hanson Otu Larbi-Siaw isaac Baffour Senkyire Department of Computer Science and Technology Jiangsu University212013ZhenjiangChina Department of Computer engineering Ghana Communication Technology UniversityGhana Department of Computer Science Ghana Communication Technology UniversityGhana Department of Telecom engineering Ghana Communication Technology UniversityGhana School of Finance and Economics Jiangsu University 212013ZhenjiangChina

Recommendation systems provide ease and convenience for users to address information overload problems while interacting with online platforms such as social media and ***,it raises several questions about privacy,especially for users who prefer to remain anonymous,especially on online social networks(OSNs).Moreover,due to the commercialization of online users'data,some service providers sell users'data to third parties at the blind side of the users,which leads to trust issues between users and service *** matters call for a system that gives online users much-needed control and autonomy of their *** the advancement of blockchain technology,many research institutions are experimenting with decentralized technologies to resolve the OSN user dilemma of privacy intrusion against third parties and *** resolve these limitations,we propose RecGuard,a privacy preservation blockchain-based network *** developed two smart contracts,RG-SH and RG-ST,to ensure the security and privacy of user *** RG-SH manages user data,whereas the RGST stores data.A graph convolutional network(GCN)was integrated with the blockchain-based system to detect malicious ***,we implemented our framework prototype on a locally simulated *** analysis and experiment results show that the proposed scheme demonstrates the effectiveness and privacy of users in our framework.

关键词： Blockchain Privacy Online social network Recommender system

Finite Element Analysis of Spur and Helical Gears

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Finite Element Analysis of Spur and Helical Gears

作者： NKURUNZIZA isaac 北京理工大学

学位级别：硕士

As one of the fundamental components,gears are widely used in various applications due to its precision transmission,high reliability,and compact structure,mature manufacturing processes,***,due to the rapid development of modern technology,such as high-speed railway,the gear transmission develops toward heavy load,high speed,high precision,low noise and high life expectancy,which demands the deep understanding of gear *** a successful analysis method,finite element method is widely applied in various stress related *** design of an effective and reliable gearing system includes its ability to withstand root bending stress（RBS）and surface contact stress（SCS）.Various research methods such as theoretical,numerical and experimental have been adopted throughout the years,however,theoretical and numerical methods are specially preferred as experimental testing may be much *** many researchers have utilized FEM to predict RBS and *** thesis conducts the analysis of micro-pitting mechanism of gear based on Finite Element Method（FEM）.Contact pressure,subsurface stress,and relative velocity of involute spur and helical gears teeth in meshing are studied with the consideration of friction coefficient *** main contents and conclusions are as follows:Finite element models of gears are built based on three-dimensional solid model and proper finite element and mesh structure are *** changes of normal force,contact pressure,and subsurface stresses are explored during the meshing *** results show that normal force,contact pressure,and subsurface stress increase first during approach process,then get maximal near the pitch point,and finally decrease during the recess *** gear shows much successive change of normal force and subsurface stress,which promote preferred *** effect of friction coefficient on the contact performance of gear is *** can be found that the increase of friction

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Refining the American Urological Association and American Society for Radiation Oncology guideline for adjuvant radiotherapy after radical prostatectomy using the pathologic Gleason score

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Asian Journal of Andrology 2017年第1期19卷 20-25页

作者： Wan Song Young Suk Kwon Seong Soo Jeon isaac Yi Kim Section of Urologic Oncology Rutgers Cancer Institute of New Jersey Rutgers The State University of New Jersey New Brunswick NJ 08903 USA Department of Urology Samsung Medical Center Sungkyunkwan University School of Medicine Seoul South Korea.

Recently, it has been suggested that the guideline for adjuvant radiotherapy （ART） following radical prostatectomy （RP） sponsored by the American Urological Association and American Society for Radiation Oncology （AUA/ASTRO） may result in a significant overtreatment. Thus, the objective of the present study was to refine the AUA/ASTRO guideline for ART in patients at risk for biochemical recurrence （BCR） after RP. To this end, we reviewed our prospectively maintained database and selected 193 patients who met the AUA/ASTRO ART criteria. With a median follow-up of 24.0 months, BCR rate was 17.6% （34/193）. When stratified by the Gleason score, BCR rate in men with Gleason score 6 was 6.8%. There was no significant association between BCR-free survival and surgical margin （P= 0.690） and pathologic stage （P= 0.353） in patients with the Gleason score 6. However, in patients with positive surgical margins （PSMs）/pathologic stage ≥T3, there was a significant difference in BCR-free survival according to Gleason score （≤7 vs8-10, P= 0.047）. Multivariate Cox regression analysis demonstrated that pathologic stage ≥T3 （HR = 2.106; P = 0.018）, PSMs （HR = 2.411; P = 0.003）, and pathologic Gleason score 8-10 （HR = 4.715; P 〈 0.001） were independent predictors of BCR after RP. Therefore, in addition to pathologic stage 〉T3 and PSMs, Gleason score 8-10 predicts 8CR after RP. In patients with Gleason score 6, observation rather than ART may be more appropriate regardless of stage and surgical margin status.

关键词： adjuvant radiotherapy biochemical recurrence radical prostatectomy

Management of pancreaticobiliary disease using a new intra-ductal endoscope:The Texas experience

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World Journal of Gastroenterology 2009年第11期15卷 1353-1358页

作者： Douglas S Fishman Paul R Tarnasky Sandeep N Patel isaac Raijman Texas Children’s Hospital Section of Pediatric Gastroenterology and NutritionBaylor College of Medicine6621 Fannin StreetHoustonTX 77030United States Digestive Health Associates Methodist Pavilion II 221 West Colorado Blvd.DallasTX 75208-2359United States Division of Gastroenterology and Nutrition The University of Texas Health Science Center at San Antonio7703 Floyd Curl Drive San AntonioTX 78229-3900United States Digestive Associates of Houston 6620 Main Street.HoustonTX 77030United States

AIM:To evaluate a new single-operator mini-endoscope, Spyglass,for its performance,feasibility and safety in the management of pancreaticobiliary disease. METHODS:In a multicenter retrospective analysis of patients undergoing intraductal endoscopy,we evaluated 128 patients(71 men,mean age 57.6 years).Indications were therapeutic(TX)in 72(56%) and diagnostic(DX)in 56(44%). RESULTS:Peroral endoscopy was performed in 121 and percutaneous in *** indications included CBD stones in 41,PD stones in six,and biliary strictures in *** indications included abnormal LFT’s in 15, abnormal imaging in 38 and cholangiocarcinoma staging in *** of the stone(s)was considered good in 31,fair in six,and poor in four. Advancement of the electrohydraulic lithotripsy probe was not possible in three patients and proper targeting of the lesion was partial in four patients.A holmium laser was used successfully in three *** clearance was achieved in 37 patients after one procedure and in four patients after two *** of biliary strictures was modified in 20/29 and confirmed to be malignant in 10/*** the modified patients,no diagnosis was available in *** demonstrated malignancy in 8/17 and non-malignancy in *** pathology by imaging studies and abnormal LFT’s was modified in 43/63(66%).Staging of cholangiocarcinoma demonstrated multicentric cholangiocarcinoma in 2/*** was no morbidity associated with the use of Spyglass. CONCLUSION:Spyglass Spyscopeis a first generation, single operator miniature endoscope that can evaluate and treat various biliary and pancreatic tract diseases.

关键词： Intra-ductal endoscopy Choledochoscopy Cholangiopancreatoscopy endoscopic retrogradecholangiopancreatography Biliary disease Sclerosingcholangitis Cholangiocarcinoma Lithotripsy Pancreaticdisease Spyglass

Pro-inflammatory cytokines profiles in Nigerian pregnant women infected with Plasmodium falciparum malaria

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Asian Pacific Journal of Tropical Medicine 2010年第9期3卷 731-733页

作者： Nmorsi OPG isaac C Ohaneme BA Obiazi HAK Tropical Diseases Research Unit Department of ZoologyAmbrose Alli UniversityEkpomaNigeria Department of Medical Laboratory Sciences Ambrose Alli UniversityEkpomaNigeria

Objective:To investigate the pro-inflammatory cytokines profiles in in Nigerian pregnant women infected with Plasmodium falciparum(***) ***:Peripheral, and placental blood samples were collected from 96 consenting volunteers comprising 76 *** infected pregnant women and 20 healthy uninfected pregnant women in ***,and subjected to ELISA for cytokines ***:Increased serum concentrations of interferon-gamma(IFN-γ) was observed in infected pregnant women than their uninfected counterparts[(31.2±20.9) pg/mL vs(1.8±0.9) pg/mL]and these differences were statistically significant(χ~2= 26.18,Pen in peripheral blood of the infected pregnant women than the uninfected women[(13.9±3.6) pg/mL vs(28.4±5.28) pg/mL]respectively was not statistically significant(χ~2= 4.96,P>0.05). The interleukin-6(IL-6) was significantly elevated in infected pregnant women(81.0±26.1 pg/mL) than in the uninfected pregnant women[(25.0±5.0) pg/mL](χ~2 = 29.58,Pentration of IL-6,IL-12 and IFN-γin the placental blood from infected pregnant women were(53.5±23.4) pg/mL,(8.7±6.9) pg/mL and(16.4±4.0) pg/mL,respectively. The multigravidae had a higher haemoglobin level of 10.2 g/dL and birth weight of 3 000 g than the primigrivadae with lower haemoglobin level of 7.5 g/dL and birth weight of 2 430 g. Conclusions:The elevated IFN-γamong the malarous pregnant women implicates it as the major cytokine mediator in the host responses to systematic *** malaria in our locality.

关键词： Pro-inflammatory cytokines Pregnant women Plasmodium falciparum Nigeria