Effect of sugar type on the survival of frozen-thawed rhesus monkey (Macaca mulatta) sperm

Sperm-freezing extenders supplemented with sugar or a combination of different sugars are widely used for the cryopreservation of nonhuman primate spermatozoa. Understanding which sugar or combination of sugars offers the highest level of cryoprotection w

Small-scale turbulent fluctuations beyond Taylor's frozen-flow hypothesis

The space-time cross-correlation function C-T(r, tau) of local temperature fluctuations in turbulent Rayleigh-Benard convection is obtained from simultaneous two-point time series measurements. The obtained C-T(r, tau) is found to have the scaling form C-T(r(E), 0) with r(E)=[(r-U tau)(2)+ V-2 tau(2)](1/2), where U and V are two characteristic velocities associated with the mean and rms velocities of the flow. The experiment verifies the theory and demonstrates its applications to a class of turbulent flows in which the requirement of Taylor's frozen flow hypothesis is not met.

An Efficient Front-Tracking Method For Fully Nonlinear Interfacial Waves

A fully nonlinear and dispersive model within the framework of potential theory is developed for interfacial (2-layer) waves. To circumvent the difficulties arisen from the moving boundary problem a viable technique based on the mixed Eulerian and Lagrangian concept is proposed: the computing area is partitioned by a moving mesh system which adjusts its location vertically to conform to the shape of the moving boundaries but keeps frozen in the horizontal direction. Accordingly, a modified dynamic condition is required to properly compute the boundary potentials. To demonstrate the effectiveness of the current method, two important problems for the interfacial wave dynamics, the generation and evolution processes, are investigated. Firstly, analytical solutions for the interfacial wave generations by the interaction between the barotropic tide and topography are derived and compared favorably with the numerical results. Furthermore simulations are performed for the nonlinear interfacial wave evolutions at various water depth ratios and satisfactory agreement is achieved with the existing asymptotical theories. (c) 2008 Elsevier Inc. All rights reserved.

Effect of glycerol and dimethyl sulfoxide on cryopreservation of rhesus monkey (Macaca mulatta) sperm

Glycerol and dimethyl sulfoxide (DMSO) are widely used as penetrating cryoprotectants in the freezing of sperm, and various concentrations are applied in different species and laboratories. The present study aimed to examine the effect of these two cryoprotectants at different concentrations (2%, 5%, 10%, and 15% glycerol or DMSO) on rhesus monkey sperm cryopreservation. The results showed that the highest recovery of post-thaw sperm motility, and plasma membrane and acrosome integrity was achieved when the sperm was frozen with 5% glycerol. Spermatozoa cryopreserved with 15% DMSO showed the lowest post-thaw sperm motility, and spermatozoa cryopreserved with 15% glycerol and 15% DMSO showed the lowest plasma membrane integrity among the eight groups. The results achieved with 5% glycerol were significantly better for all parameters than those obtained with 5% DMSO. The functional cryosurvival of sperm frozen with 5% glycerol was further assessed by in vitro fertilization (IVF). Overall, 85.7% of the oocytes were successfully fertilized, and 51.4% and 5.7% of the resulting zygotes developed into morulae and blastocysts, respectively. The results indicate that the type and concentration of the penetrating cryoprotectant used can greatly affect the survival of rhesus monkey sperm after it is frozen and thawed. The suitable glycerol level for rhesus monkey sperm freezing is 5%, and DMSO is not suitable for rhesus monkey sperm cryopreservation. (C) 2004 Wiley-Liss, Inc.

杜泊绵羊冷冻胚胎移植

介绍了从新西兰引进的冷冻杜泊羊胚胎解冻后移植到同期发情湖羊和小尾寒羊母羊受体的方法步骤,并分析、评价了胚胎移植的效果。结果表明:受体羊总平均同期发情率为78.4%,胚胎移植利用率达49.1%,妊娠率达59.4%,产羔率达58.0%,羔羊出生重为4.7 kg(公)和4.3 kg(母),羔羊1月龄和3月龄体重分别为14.9kg和32.4 kg;不同批次和不同品种受体间胚移效果亦存在不同程度的差异;4批次试验共移植冷冻胚胎475枚,产羔266只,现存活245只。该研究建立了可靠而有效的杜泊绵羊冷冻胚胎移植技术,有望在畜牧业科研和生产中广泛推广应用。

影响杜泊羊冷冻胚胎移植成功率的因素

采用引进的杜泊羊冷冻胚胎, 以云南当地绵羊为受体进行胚胎移植。同期发情处理了158 只受体 羊, 同期发情率为82191 %; 对102 只进行了胚胎移植, 实际移植率为77186 % , 3 个情期内移植妊娠率达 7415 %; 出生68 只, 产羔率达6617 %。分析表明, 胚胎发育阶段及级别、卵巢黄体情况、以及胚胎移植技术 熟练程度直接影响胚胎移植成功率; 此外, 受体羊的处理程序及移植后的饲养管理、移植时机的把握、移植季 节以及胚胎冷冻及解冻方法也会影响杜泊羊移植妊娠率, 进而影响产羔率。

Cryopreservation of cynomolgus monkey (Macaca fascicularis) spermatozoa in a chemically defined extender

Aim: To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. Methods: Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris (mTTE) synthetic extender and glycerol as cryoprotectant. The effects of glycerol concentration (1%,3%, 5%, 10% and 15% [v/v]) and its equilibration time (10 min, 30 min, 60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity. Results: The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P < 0.05) for 5% glycerol (42.95 +/- 2.55 and 50.39 +/- 2.42, respectively) than those of the other groups (1%: 19.19 +/- 3.22 and 24.84 +/- 3.64; 3%: 34.23 +/- 3.43 and 41.37 +/- 3.42; 10%: 15.68 +/- 2.36 and 21.39 +/- 3.14; 15%: 7.47 +/- 1.44 and 12.90 +/- 2.18). The parameters for 30 min equilibration (42.95 2.55 and 50.39 2.42) were better (P < 0.05) than those of the other groups (10 min: 31.33 +/- 3.06 and 38. 98 +/- 3.31; 60 min: 32.49 +/- 3.86 and 40.01 +/- 4.18; 90 min: 31.16 +/- 3.66 and 38.30 +/- 3.78). Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity. Conclusion: Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender, which is related to the concentration and the equilibration time of glycerol.

Effects of various extenders and permeating cryoprotectants on cryopreservation of cynomolgus monkey (Macaca fascicularis) spermatozoa

The cryoprotective effects of 11 different extenders, TTE, DM, mDM, LG-DM, G-DM, TCG, TEST, TSM, Test-M, Test-H, and LM, on sperm cryopreservation of cynomolgus monkey (Macaca fascicularis) have been compared with glycerol as cryoprotectant. Sperm motility, plasma membrane, and acrosomal integrity were examined to evaluate frozen-thawed sperm function. The results showed that TTE, DM, mDM, LG-DM, G-DM, and TCG exhibited the best and similar protective efficiencies for cynomolgus monkey sperm cryopreservation in terms of sperm motility and plasma membrane integrity (P > .05). The acrosomal integrity for spermatozoa cryopreserved in TCG was statistically lower than that of TTE, DM, mDM, LG-DM, and G-DM (P < .05) but was significantly higher than that of TEST, TSM, Test-M, Test-H, and LM (P < .05). The postthaw sperm motility for 5 other extenders (TEST, TSM, Test-M, Test-H, and LIVI) did not exceed 30%, and the 3 sperm parameters evaluated for them were significantly lower than that of TTE, DM, mDM, LG-DM, G-DM, and TCG (P < .05). On the basis of these findings, 5 commonly used permeating cryoprotectants, glycerol, ethylene glycol, dimethyl sulfoxide, acetamide and propylene glycol have further been tested for their effectiveness on sperm cryopreservation in extenders of TTE, DM, mDM, LG-DM, G-DM, and TCG. The results showed that the sperm cryoprotective efficiencies of glycerol and ethylene glycol were similar and best among 5 permeating cryoprotectant treatments (P > .05). Dimethyl sulfoxide or acetamide resulted in average cryoprotection for cynomolgus monkey spermatozoa: poorer than glycerol or ethylene glycol but better than that of propylene glycol (P < .05). In addition, the action of permeating cryoprotectant appeared to be independent of extenders. The results in the present study demonstrate that 1) TTE, DM, mDM, LG-DM, G-DM, and TCG are excellent extenders and suitable for cynomolgus monkey sperm cryopreservation; 2) the mechanism of action of permeating cryoprotectants are not affected by extender composition; 3) ethylene glycol has a similar cryoprotective efficacy to glycerol that makes it a successful cryoprotectant for sperm cryopreservation in cynomolgus monkeys.

Comparative studies with six extenders for sperm cryopreservation in the cynomolgus monkey (Macaca fascicularis) and rhesus monkey (Macaca mulatta)

Ejaculated spermatozoa from cynomolgus monkeys and rhesus monkeys were frozen in straws with six different extenders (TTE, DM, mDM, LG-DM, G-DM, and TCG) containing glycerol. Sperm motility and head membrane and acrosomal integrity were evaluated after fr

INTERVALLEY-GAMMA-CHI DEFORMATION POTENTIALS IN III-V ZINCBLENDE AND SI SEMICONDUCTORS BY AB-INITIO PSEUDOPOTENTIAL CALCULATIONS

Intervalley GAMMA - X deformation potential constants (IVDP's) have been calculated by first principle pseudopotential method for the III-V zincblende semiconductors AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs and InSb. As a prototype crystal we have also carried out calculations on Si. When comparing the calculated IVDP's of LA phonon for GaP, InP and InAs and LO phonon for AlAs, AlSb, GaAs, GaSb and InSb with a previous calculation by EPM in rigid approximation, good agreements are found. However, our ab initio pseudopotential results of LA phonon for AlAs, AlSb, GaAs, GaSb and InSb and LO phonon for GaP, InP and InAs are about one order of magnitude smaller than those obtained by EPM calculations, which indicate that the electron redistributions upon the phonon deformations may be important in affecting GAMMA - X intervalley shatterings for these phonon modes when the anions are being displaced. In our calculations the phonon modes of LA and LO at X point have been evaluated in frozen phonon approximation. We have obtained, at the same time, the LAX and LOX phonon frequencies for these materials from total energy calculations. The calculated phonon frequencies agree very well with experimental values for these semiconductors.

INTERVALLEY GAMMA-CHI DEFORMATION POTENTIALS IN III-V ZINCBLENDE SEMICONDUCTORS BY ABINITIO PSEUDOPOTENTIAL CALCULATIONS

Intervalley GAMMA-X deformation-potential constants (IVDP's) have been calculated by use of a first-principles pseudopotential method for the III-V zinc-blende semiconductors AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, and InSb. When the calculated IVDP's of LA phonons for GaP, InP, and InAs and of LO phonons for AlAs, AlSb, GaAs, GaSb, and InSb are compared with results of a previous calculation that used the empirical pseudopotential method (EPM) and a rigid-ion approximation, good agreement is found. However, our ab initio pseudopotential results on IVDP's of LA phonons for AlAs, AlSb, GaAs, GaSb, and InSb and of LO phonons for GaP, InP, and InAs are about one order of magnitude smaller than those obtained by use of EPM calculations, indicating that the electron redistribution accompanying crystal-lattice deformation has a significant effect on GAMMA-X intervalley scattering for these phonon modes when the anions are being displaced. In our calculations the LA- and LO-phonon modes at the X point have been evaluated in the frozen-phonon approximation. We have also obtained the LAX- and LOX-phonon frequencies for these materials from total-energy calculations, which agree very well with experimental values for these semiconductors. We have also calculated GAMMA-X hole-phonon scattering matrix elements for the top valence bands in these nine semiconductors, from which the GAMMA-X IVDP's of the top valence bands for the longitudinal phonons and transverse phonons are evaluated, respectively.

1ST PRINCIPLES PSEUDOPOTENTIAL CALCULATIONS OF ZONE BOUNDARY PHONON FREQUENCIES OF III-V-ZINCBLENDE SEMICONDUCTORS

Longitudinal zone boundary X phonon frequencies have been calculated by a first principles pseudopotential method for III-V zincblende semiconductors AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs and InSb. The phonon frequencies have been evaluated from total energy calculations in the frozen phonon approximation. The calculated phonon frequencies agree very well with the experimental values.

耗散粒子动力学处理复杂固体壁面的一种有效方法

耗散粒子动力学(dissipative particle dynamics,DPD)作为一种介观尺度拉格朗日型粒子方法,已经成功地应用于微纳米流动和生化科技的研究中. 复杂固体壁面的处理和壁面边界条件的实施一直是DPD方法发展及应用的一个障碍. 提出了处理复杂固体壁面的一种新的方法. 复杂固体区域通过冻结随机分布并且达到平衡状态的DPD粒子代表;所冻结的DPD粒子位于临近流动区域的一个截距内;在靠近固体壁面的流动区域中设置流动反弹层,当流动DPD粒子进入此流动层后反弹回流动区域. 应用这种固体壁面处理方法.