检索结果-南通市图书馆

Effect of cholesterol-loaded cyclodextrin enriched extenders on the quality of pre- frozen and frozen buffalo semen

Asian pacific Journal of Reproduction 2022年第3期11卷 146-152页

作者： Asmaa A.Mostafa Mohamed S.el-Belely Sayed T.ismail reda i.el-sheshtawy Mohamed i.Shahba Abassia Frozen Semen Center General Organization for Veterinary ServicesCairoEgypt Department of Theriogenology Faculty of Veterinary MedicineCairo UniversityGizaEgypt Department of Animal Reproduction and Artificial insemination National Research CentreDokkiGizaEgypt

Objective:To investigate the effects of non-permeable cryoprotectant,cholesterol-loaded cyclodextrin,when added at different concentrations into cooled and frozen-thawed semen extended with Tris-citrate-fructose egg yolk glycerol and lecithin-based extenders.Methods:A total of 40 ejaculates from four buffalo bulls were collected using artificial vagina.Ejaculates were extended with one of Tris-citrate-fructose egg yolk glycerol and lecithin-based extenders which contained different concentrations[0(control),0.75,1.50,2.25 and 3.00 mg/mL]of cholesterol-loaded cyclodextrin.The extended semen samples were cooled to 5曟and then frozen slowly to-196曟in 0.25 mL ministraws before being stored in liquid nitrogen pending its evaluation.Sperm motility,live sperm,normal sperm morphology,sperm membrane integrity and acrosome morphology were measured.Results:Supplementation of cholesterol-loaded cyclodextrin improved progressive motility,viability,morphology and acrosome as well as plasma membrane integrities at 1.50-2.25 mg/mL depending upon types of used extenders and stages of pre-and post-freezing process(Pion was 1.50 mg/mL at pre-freeze stage and 2.25 mg/mL at post-freezing.However,greater concentration(3.00 mg/mL)of cholesterol-loaded cyclodextrin had a detrimental effect compared to the control group with the two evaluated extenders(Pions:Cholesterol-loaded cyclodextrin supplementation at 1.50-2.25 mg/mL concentration could improve pre-frozen and post-thawed buffalo sperm quality.The most suitable concentration is 1.50 mg/mL at pre-freeze stage and 2.25 mg/mL at post-freezing.

关键词： Buffalo Semen Tris Cooling Cryopreservation Cholesterol-loaded cyclodextrin Semen evaluation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of butylated hydroxytoluene on quality of pre-frozen and frozen buffalo semen

引用

Asian pacific Journal of Reproduction 2019年第1期8卷 20-24页

Objective: To clarify the antioxidant effect of butylated hydroxytoulene (BHT) at different concentrations on cooled and post frozen semen diluted in tris-citrate-fructose egg yolk glycerol and lecithin -based extenders. Methods: Forty ejaculates were harvested from four buffalo bulls by means of the artificial vagina. Ejaculated semen samples were diluted with each of the tris citrate-fructose egg yolk glycerol and lecithin-based extender diluents. The semen samples diluted with each of the two extenders were added to pre-warmed dried test tubes containing BHT (prepared in ethanol) to get concentrations at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mM/mL BHT. These ingredients were put at 37 ℃ for 5 min to allow the proper BHT spermatozoal permeation. The diluted semen samples were cooled to 5 ℃ and then frozen to -196 ℃ in 0.25 mL ministraws before dipping in liquid nitrogen pending its evaluation. Sperm motility, viability, morphology, intact acrosome and membrane integrity were tested. Visual motility was tested using a high power ordinary microscope (at 400 × ) with closed circuit television, and sperm concentration was tested using Neubauer haemocytometer and abnormality % using eosin-nigrosin stain. Spermatozoal membrane integrity was tested using the hypo-osmotic swelling test. The sperm with swollen twisting tail was normally intact. Sperm acrosomal integrity % was tested as mentioned by Watson. Results: Addition of BHT improved (Pive motility, viability, morphology and acrosome as well as plasma membrane integrities at 0.5-2.0 mM/mL depending upon types of used extenders and stages of pre-and post-freezing process. Higher levels of 2.5 and 3.0 mM/mL BHT had a deteriorating (Pif compared to the control and all extenders assayed. Conclusions: BHT addition at lower concentration can improve pre-frozen and post-thawed buffalo sperm quality.

关键词： Butylated hydroxytoulene Lecithin Egg yolk Buffalo semen Cryopreservation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

impact of replacing egg yolk with lecithin on quality of pre-freeze and post-thaw buffalo spermatozoa

引用

Asian pacific Journal of Reproduction 2018年第6期7卷 254-260页

作者： Asmaa A.Mostafa Mohamed.S.el-Belely Sayed.T.ismail reda.i.el-sheshtawy Mohamed i.Shahba Abassia Frozen Semen Center General Organization for Veterinary ServicesCairoEgypt Department of Theriogenology Faculty of Veterinary MedicineCairo UniversityGizaEgypt Animal Reproduction and Artificial insemination Department National Research CentreDokkiGizaEgypt

Objective:To estimate the result of egg yolk replacement with alternative cryopreservatives such as plant-derived lecithin from soybean on sperm quality parameters pre and post freezing in buffalo bulls.Methods: The control cryopreservation extender was tris-citric acid-fructose-egg yolk-glycerol (TCFYG) diluent. Semen samples were extended gradually 1:10 with TCFYG control extender and tris-citric acid-fructose-glycerol (TCFG) extender plus variable concentrations of soybean lecithin (0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0%) to ensure 60 million active spermatozoa/mL of the extended semen. The diluted semen samples were refrigerated slowly (roughly for 2 h) up to 5℃ and equilibrated for 2 h. Semen was filled into 0.25 mL polyvinyl French straws (iMV, France). After equilibration period, the straws were placed horizontally on a rack and frozen in a vapor 4 cm above liquid nitrogen for 10 min and were then dipped stored in liquid nitrogen at -196℃. Results:The respective overall percentages of forward motile spermatozoa, live spermatozoa, morphologically normal spermatozoa, acrosome integrity and hypo-osmotic swelling reactivity observed primarily in fresh semen, after equilibration (pre-freeze stage) and post freezing (post-thaw stage) in TCFYG (control) extended semen declined progressi.ely and statically (Ping these periods of study. Pre-freezing stage: replacement of egg yolk into TCFG with soybean lecithin at concentrations of 1.0% and 1.5% significantly (Peliorated the maintenance of (motility, viability, acrosome and membrane integrity %), meanwhile it had significantly (Pity % of spermatozoa to the lowest value compared to control TCFYG and to some other concentrations in use. Post-thaw stage: the replacement of egg yolk with 1.0% soybean lecithin (SL) showed significantly (Pigher percentage of sperm progressive motility compared to 1.5% SL and TCFYG control. These values were significantly (Pigher than 0.5%, 2.0%, 2.5% and 3.0% SL. The post thawi

关键词： Buffalo Semen Preservation Soybean lecithin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Thermal performance of domed roof in air-conditioned spaces

Energy and Built Environment

引用

Energy and Built Environment 2024年第2期5卷 270-287页

作者： ibrahim reda Raouf N.AbdelMessih Mohamed Steit Ehab M.Mina Mechanical Power Engineering Faculty of EngineeringAin Shams University1 El-Sarayat St.Cairo 11517Egypt Architectural Engineering Faculty of EngineeringAin Shams UniversityCairoEgypt

Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in buildings.The thermal performance of domed roofs has been investigated in many naturally ventilated spaces.However,few studies have discussed their performance in conditioned spaces.Therefore,this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque.At an earlier stage,field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021,in addition to validating the computational model.The findings of this study confirm that,under mechanical cooling conditions,the flat roof offers a lower indoor temperature than the domed roof by 0.4℃and 0.1℃for open and closed doors,respecti.ely.Similarly,the air velocity is lower by approximately 0.01 m/s for both door modes.The overall PMV values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,respecti.ely.Based on these small differences,it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces.However,the air patterns are substantially different,the overall thermal performance is similar.This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate,regardless of their aesthetic and acoustical behaviour.

关键词： Thermal comfort Computational fluid dynamics(CFD) Predicted mean vote(PMV)and predicted percentage dissatisfied(PPD) Domed roof Flat roof

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cryopreservation of cattle semen using coconut water extender with different glycerol concentrations

引用

Asian pacific Journal of Reproduction 2017年第6期6卷 279-282页

作者： reda ibrahim el-sheshtawy Walid Said el-Nattat Gamal Abdel Daiem Ali Animal Reproduction and Al Department Veterinary DivisionNational Research CentreDokkiGizaEgypt

Objective:To investigate the effect of coconut water with a lone concentration and different concentrations of glycerol on chilled and cryopreserved cattle semen characteristics.Methods: Semen was collected from five mature cattle bulls, at weekly intervals for 5 weeks. The ejaculates were pooled and evaluated for dilution processing. Tris citrate egg yolk fructose was used as control treatment for semen, while 50% (V/V) coconut water, 25% (V/V) bi-distilled water and 25% (V/V, 5% anhydrous monosodium citrate) to 20 mL egg yolk and three different concentrations of glycerol (4%, 6% and 8%) were used as coconut water (CW)-glycerol-yolk extenders (CWCG-4, CWCG-6 and CWCG-8). Extended semen was cooled and cryopreserved. Sperm motility%, sperm membrane integrity%, normal acrosome%, live sperm% and total sperm abnormalities% were recorded after equilibrium and after freeze-thawing.Results:The addition of 4% glycerol to coconut water enriched media (CWCG-4) revealed the most effective addition of glycerol on all parameters after equilibrium and after freeze-thawing.Conclusions:Coconut water enriched media with 4% glycerol addition is safe to be used as an extender in bull semen preservation because it is a sterile liquid. So, it can be used without addition of antibiotics to the extender, as antibiotics have to some extent hazardous effect on spermatozoa.

关键词： Semen Glycerol Coconut water Freeze thawing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Anisotropic alignments of hierarchical Li2SiO3/TiO2@nano-C anode//LiMnPO4@nano-C cathode architectures for full-cell lithium-ion battery

引用

National Science Review 2020年第5期7卷 863-880页

作者： Hesham Khalifa Sherif A. el-Safty Abdullah reda Mohamed A. Shenashen Alaa i.Eid Research Center for Functional Materials National Institute for Materials Science Department of Petrochemical Egyptian Petroleum Research Institute Composite Lab Advanced Materials Division Central Metallurgical R&D Institute

We report on low-cost fabrication and high-energy density of full-cell lithium-ion battery (LiB) models.Super-hierarchical electrode architectures of Li2SiO3/TiO2@nano-carbon anode (LSO.TO@nano-C) and high-voltage olivine LiMnPO4@nano-carbon cathode (LMPO@nano-C) are designed for half-and full-system LiB-CR2032 coin cell models.On the basis of primary architecture-power-driven LiB geometrics,the structure keys including three-dimensional (3D) modeling superhierarchy,multiscale micro/nano architectures and anisotropic surface heterogeneity affect the buildup design of anode/cathode LiB electrodes.Such hierarchical electrode surface topologies enable continuous in-/out-flow rates and fast transport pathways of Li+-ions during charge/discharge cycles.The stacked layer configurations of pouch LiB-types lead to excellent charge/discharge rate,and energy density of237.6 Wh kg-1.As the most promising LiB-configurations,the high specific energy density of hierarchical pouch battery systems may improve energy storage for long-driving range of electric vehicles.indeed,the anisotropic alignments of hierarchical electrode architectures in the large-scale LiBs provide proof of excellent capacity storage and outstanding durability and cyclability.The full-system LiB-CR2032 coin cell models maintain high specific capacity of～89.8%within a long-term life period of2000 cycles,and average Coulombic efficiency of99.8%at 1C rate for future configuration of LiB manufacturing and commercialization challenges.

关键词： lithium-ion batteries micro/nano architectures LiMnPO4@nano-carbon cathode Li2SiO3/TiO2@nano-carbon anode LiB-CR2032 coin cell models

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Egyptian heavy vacuum gas oil hydrotreating over Co-Mo/CNT and Co-Mo/γ-Al2O3 catalysts

引用

燃料化学学报 2016年第7期44卷 853-861页

作者： W.Ahmed Hoda,S.Ahmed H.S.el-sheshtawy Nadia,A.Mohamed Asmaa,i.Zahran Egyptian Petroleum Research institute 1Aahmed El-Zomor st.Naser city 11727CairoEgypt Ain-Shams University for Girls Roqqsy SquireCairoEgypt

The catalytic activity of CoMoS /CNT towards the Egyptian heavy vacuum gas oil hydrotreating was studied. The delivered CNT was functionalized with 6 mol /L HNO_3. The CNT were loaded with 12% MoO_3( by weight) and 0.7 Co /Mo atomic ratio with impregnation methods. The γ-Al_2O_3 catalyst was also prepared by impregnation method to compare both catalysts activities.The analysis tools such XRD,Raman spectroscopy,TEM,and BET were used to characterize the catalysts. The autoclave reactor was used to operate the hydrotreating experiments. The hydrotreating reactions were tested at various operating conditions of temperature 325-375 ℃,pressure 2-6 MPa,time 2-6 h,and catalyst /oil ratio( by weight) of 1 ∶75,1 ∶33 and 1 ∶10. The results revealed that the CoMoS /CNT was highly efficient for the hydrotreating more than the CoMoS /γ-Al_2O_3. Also, the hydrodesulfurization( HDS) increased with increasing catalyst /oil ratio. Additionally,results showed that the optimum condition was temperature 350℃,pressure 4 MPa,catalyst /oil ratio of 1 ∶75 for 2 h. Furthermore,even at low CoMoS /CNT catalyst /oil ratio of 1 ∶75,an acceptable HDS of 77.1% was achieved.

关键词： hydrotreatment hydrodesulfurization carbon nanotube heavy vacuum gas oil(HVGO)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

impact of silymarin enriched semen extender on bull sperm preservability

引用

Asian pacific Journal of Reproduction 2017年第2期6卷 81-84页

作者： el-sheshtawy Ri.el-Nattat WS Animal Reproduction and Ai Dept. Veterinary Research DivisionNational Research CentreDokkiEgypt

Objective:To explore the effect of silymarin on bull spermatozoa during cooling and cryopreservation. Methods: Pooled bull semen were diluted by Tris-Citrate-Fructose egg yolk diluents, purified silymarin powder (obtained from the milk thistle silybum marianum), purchased from Unipharma, Al Obour city, Egypt, was soaked in Tris-citric acid-fructose diluent for 48 h at 10℃ making a stock solution (70 mg/mL), from this stock solution we obtained concentrations of 0.18 mg/mL, 0.36 mg/mL, 0.54 mg/mL, 0.72 mg/mL, 0.90 mg/mL in addition to the control (0.0 mg/mL) reaching a final volume of 5 mL in each tube. Egg yolk was added to each tube to obtain silymarin enriched semen extender (SEE) with 20% egg yolk, cooled slowly up to 5℃ and equilibrated for 4 h. Semen was packed into 0.25 mL polyvinyl French straws (iMV, France). After equilibration periods, the straws were placed horizontally on a rack and frozen in a vapor 4 cm above liquid nitrogen for 10 min and were then dipped in liquid nitrogen. Extended semen was subjected to evaluation (motility, alive %, abnormality %, intact sperm membrane (HOST)% and conception rate) in both chilled and frozen semen.Results: Table 1 revealed that Sperm motility of the concentrations 2, 3 and 4 after 8 d of chilling were significantly (Pigher than control. Sperm motility of the concentration 2 (45.00%±2.89%) after 9 d of chilling was higher than control and the other concentrations. Addition of SEE in concentration 1 and 2 gave post thawing sperm motility as high as the control (47.50±2.81 and 45.00±2.58, respecti.ely) while other concentration have lower effects on motility as compared to the control. Addition of silymarin improved post thawing alive% and was significantly higher (Pignificantly (Ping abnormal sperm in concentration 3 and 4 (11.83±0.65 and 16.00±0.58, respecti.ely). SEE improved significantly (Ping intact spermatozoa membranes (HOST%) in concentrations 2, 4 and 5

关键词： Cattle Semen Preservation Silymarin

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability

引用

Asian pacific Journal of Reproduction 2018年第2期7卷 93-96页

作者： el-sheshtawy Ri.el-Nattat WS Animal Reproduction and Artificial insemination Department Veterinary DivisionNational Research CenterDokkiGiza

Objective:To evaluate effect of tris-extender supplemented with various concentrations of strawberry (Fragaria spp.) on bull semen preservability.Methods: Pooled bull semen were extended with tris-citrate-fructose egg yolk diluent (control, 0% strawberry) and various concentrations of tris strawberry (TSB) (1%-6%) to achieve 60 million motile spermatozoa per milliliter. Extended semen were subjected to semen freezing protocol. Semen assessment including motility, alive%, abnormality%, intact sperm membrane (hypo-osmotic swelling test) and conception rate were carried out for both chilled and frozen semen. Results: Results showed that sperm motility after chilling was enhanced in groups treated with various concentrations of TSB from 1% to 5% and exhibited higher significance (Pilling. in frozen semen, 3%, 4%, 5% and 6% concentrations gave the best significance (Pility in comparison with the control. Concentration 1% revealed the highest significance (Pive% as compared to the control. Hypo-osmotic swelling test was maintained as the control. Concentration 3% gave the lowest significance (Pidering abnormality%. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 5% and 6% in cattle.Conclusions: it is concluded that 1%-5% concentrations of TSB ameliorate bull semen characteristics after chilling, and 3%-6% concentrations of TSB improve bull semen characteristics after freezing. Higher conception rate exists in 5% and 6% concentration of TSB.

关键词： Cattle Semen Preservation Strawberry

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effect ofDiospyros kakienriched extender on cattle bull sperm parameters and conception rate

引用

Asian pacific Journal of Reproduction 2017年第3期6卷 128-132页

作者： el-sheshtawy Ri.el-Nattat WS Animal Reproduction and Ai Department. Veterinary Research DivisionNational Research CentreDokkiEgypt

Objective:To explore the effect of Diospyros kaki on cattle spermatozoa during chilling and cryopreservation.Methods: Five milliliter of blended Persimmon (Diospyros kaki) flesh was added to 45 mL TCF to obtain 10% stock solution. Kaki enriched extender (KEE) was prepared by adding to TCF in concentrations 0.0/5.0 mL (control, 0%), 0.5/4.5 mL (1%), 1/4 mL (2%), 1.5/3.5 mL (3%), 2.0/3.0 mL (4%), 2.5/2.5 mL (5%), 3.0/2.0 mL (6%), 3.5/1.5 mL (7%), 4.0/1.0 mL (8%), 4.5/0.5 mL (9%) and 5.0/0.0 mL (10%) to obtain a final volume 5 mL in each tube. Whole egg yolk was added to each tube to obtain KEE with 20% egg yolk (KEEY), all tubes were centrifuged to get rid of debris. Semen was added to the supernatants in other tubes. Extended semen was subjected to evaluation (motility, alive sperm and intact sperm membrane (HOST) %) in both chilled and cryopreserved semen. Conception rate was carried out.Results:Sperm motility was significantly (Pigh after 11 d of chilling with the concentration 1%, 2%, 3%, 4%, 5% as compared to the control (41.67±1.67, 41.67±1.67, 40.00±0.00, 41.67±1.67 and 41.67±1.67, respecti.ely) and also non-significantly kept high at the other concentrations up to 9 d of chilling. Addition of KEE had significantly (Pimproved post thawing sperm motility % with the concentrations 1, 2, 3, 4, 5 and 6% as compared to the control (51.67±5.27, 55.00±3.16, 48.33±1.05, 45.00±3.96, 57.00±2.50, 55.00±5.00 and 43.33±5.11 respecti.ely).While the other concentrations exhibit no effect. Addition of KEE maintained alive sperm%, abnormalities% and % of intact spermatozoa membranes (HOST %) as good as the control with all concentrations of kaki used in our study. The conception rate upon using frozen semen in insemination showed higher conception rate in concentrations of 2%, 4% and 6 % KEE in cattle.Conclusion: it could be concluded that some concentrations ofDiospyros kaki improved bull semen quality post-chilling and post-freezing.

关键词： Cattle Semen Preservation Diospyros kaki

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：