雌性大鼠生育力与早期胚胎发育毒性阳性模型建立及比较

目的比较Sprague Dawley(SD)雌性大鼠交配前给予不同剂量和次数的环磷酰胺(Cyclophosphamide,CTX)后生殖和发育指标的变化,建立生育力与早期胚胎发育毒性试验(Ⅰ段)标准化阳性对照模型。方法SD大鼠150只,雌雄各半,按体重随机分为溶媒对照组、CTX 20 mg/kg和CTX 100 mg/kg组,每组50只,雌雄各半。雌性大鼠于交配前14 d分别按5次和1次腹腔注射(intraperitoneal,ip)给予20 mg/kg和100 mg/kg的CTX,每日1次;溶媒对照组同途径给予等量生理盐水。用于交配的各组雄性大鼠不给药;每天观察SD大鼠一般状况,每周测定2次体重和1次摄食量。雌性大鼠于妊娠第14天(GD14;查到精子或阴栓日为GD0)处死进行终末检查并计算妊娠率、着床前丢失率、着床率、平均黄体数、平均着床数、着床后丢失率、平均活胎数、活胎率、子宫连胎重和吸收胎率等指标。结果与溶媒对照组相比,CTX各组SD大鼠体重和摄食量均明显降低(P<0.05或P<0.01),妊娠率、着床前丢失率、着床率、平均黄体数和平均着床数均无统计学差异;CTX 20 mg/kg组子宫连胎重明显降低(P<0.01);CTX 100 mg/kg着床后丢失率明显增加(P<0.01),平均活胎数、活胎率、子宫连胎重明显偏低,吸收胎率明显偏高(P<0.05或P<0.01)。结论雌性SD大鼠于交配前14 d按20 mg/kg和100 mg/kg分别以5次和1次腹腔注射给予CTX,均可以成功地建立SD雌性大鼠生育力与早期胚胎发育毒性阳性模型,且CTX按100mg/kg给药1次的给药方案为最佳选择。

Optimization of Isolation and Identification Conditions of Glibenclamide Annotation

A method for dispersive liquid-liquid microextraction of glibenclamide on model mixtures with urine has been developed. The extraction conditions have been optimized and the influence of extractants and dispersing agent for allocation of toxicant from biosubstrate has been experimentally established. The method of TLC （thin layer chromatography） screening in order to remove endogenous and exogenous substances has been developed. The method of IR-spectroscopy for confirmatory analysis has been used. The combination of the two methods of analysis allows identifying glibenclamide quickly and reliably isolated from bioliquid and reducing the risk of false-positive results.

Simulating the Performance of Solar Water Heating Systems

This paper presents a software for simulating the thermal performance of solar water heating systems. The implemented model computes the energy balance in the hot water storage tank in each time step along a simulation interval. Its input data are values from a typical meteorological year of a chosen location and the hot water load. The system components are the hot water storage tank and the solar collector. Firstly, the validation of the model is presented and then four solar water heating systems are simulated in four different cities along one year. The storage tank water hourly temperatures were obtained for a typical meteorological year and those values were compared with the values obtained by the widespread TRNSYS simulation software. The results obtained from this comparison were satisfactory.

血站核酸筛查模式对输血传播HBV残余风险影响的评估研究

目的初步评估探讨核酸筛查模式对献血人群乙型肝炎病毒(hepatitis B virus,HBV)传播残余风险度的影响。方法采用中国大陆执业比对工作组信息管理系统的相关数据,利用NAT单阳性率-窗口期比率数学模型(NAT yield/WP ratio model),对2015—2019年度我国18家血液中心的献血人群HBV传播的残余风险度进行趋势分析;同时分析比较2019年18家血液中心的ELISA联合核酸单检/混检(ELISA+ID-NAT/MP-NAT)和ELISA联合核酸混检(ELISA+MP-NAT)2种血液筛查(简称血筛)模式对残余风险度的影响。结果18家血液中心5年的HBV血筛残余风险度总体趋势经趋势卡方检验显示:核酸检测单阳性率趋势χ^(2)=39.42(P<0.01),残余风险度趋势χ^(2)=279.792(P<0.01);ELISA+ID-NAT/MP-NAT和ELISA+MP-NAT 2种不同血筛模式对残余风险度RR的影响差异有显著统计学意义,卡方检验显示χ^(2)=7.4(P<0.01)。结论自2015年我国将核酸检测用于血筛以来,HBV输血传播的残余风险度呈逐年下降趋势,目前主要的2种血筛模式对血液残余风险度有可能造成差别。

Drag-reduction of a nonionic surfactant aqueous solution and its rheological characteristics

In order to develop turbulent drag-reducing technology by using an environmentally friendly additive in a water-transporting system,the drag reducing characteristics in a non-ionic surfactant(Oleyldimethylamineoxide,ODMAO) dilute aqueous solution flowing in a circular pipe of 5 mm diameter have been experimentally investigated with an air-driven fluid resistance test device.The rheological characteristics of the solution have also been examined by a rheometer with a cone-plate flow cell.The results show that the ODMAO solutions are drag-reducing when concentration is 400 ppm or higher,that the critical Reynolds number corresponding to the maximum drag reduction rate increases with both concentration and temperature,and that the maximum drag reduction rate can reach up to 70% in the straight pipe.At low shear rates,the shear viscosity of ODMAO solutions with a relatively high drag-reduction behaves similarly to Newtonian fluids;at above a certain critical shear rate,it is firstly shear-thickening,then shear-thinning.Such shear-rate-dependent characteristics of the shear viscosity are attributed to the different transitions of micellar network structure induced by different shear rates.Relaxation of shear stress after removing an applied constant shear rate at which the solution is in the SIS(shear-induced structure) state is found to be well expressed by a 2-step Maxwell model with a tail relaxation time much shorter than that for a drag-reducing cationic surfactant,which indicates that for the ODMAO solution,a viscoelasticity as strong as a drag-reducing cationic surfactant is not needed to realize turbulent drag-reduction.

Control of large angle maneuvers for the flexible solar sail

Solar sail is a new type of spacecraft for deep space exploration,which flies by the pressure of sunlight.The attitude of the sail determines its orbit,so altitude control plays an important role in the mission.However,the large flexible structure leads to some difficulty in attitude control.This paper establishes the reduced dynamic model of a flexible solar sail with foreshortening deformation,and coupling with its attitude and vibration.As usual,large angle maneuvering will lead to the vibration of flexible structure,so the time optimal control of solar sail maneuvering is considered.Bang-Bang control of the solar sail generates large amplitude and sustained vibration,while the combined control based on input shaping can eliminate the vibration efficiently.With the comparison of two reduced models,it is demonstrated that the choice of two models depends on the attention to the stretching deformation.

A curved surface solar radiation pressure force model for solar sail deformation

A precise force model is of vital importance for dynamics and control of solar sails. Among various factors, deviations from the ideal flat sails, elastic deformations of the sails, are really important as most solar sails are large flexible membranes. In this study, the deformed sails are modeled as smooth curved surfaces and a general total force model (GTFM) for the deformed sails is proposed. Various simplified versions of this GTFM are also derived for the symmetric deformation cases. Furthermore, differences between the ideal force models and our precise GTFM are investigated. The numerical results demonstrate that both the previous ideal reflected model and flat optical model are not as satisfactory as claimed before, by contrast with the actual dynamics from the GTFM. Thus this work paves the way for sail craft's precise navigation where exact forces are needed.