Quantified ultrastructural study of spermatozoa in unexplained failure of in vitro fertilization

Failure of in vitro fertilization or very low cleavage rates may occur even though oocyte and semen parameters seem satisfactory. Quantified ultrastructural study of spermatozoa was performed in such cases of failure (n =6) or low cleavage rate (<20%; n =4). Through 1 to 11 retrievals, the number of inseminated oocytes ranged from 14 to 145. The results were compared to those of six fertile men. Quantification was achieved by cataloguing cell defects of the spermatozoon heads and mid-/principal pieces of the flagella. Using the data from each specimen, the percentages of total cellular abnormalities in the head/mid-/principal pieces were established. At the level of the head overall percentages for six groups of defects were determined. The overall percentage of combined head abnormalities, defined as the presence of at least three of these six defects on the same spermatozoon head, was established. Statistical differences among control and patient groups were analyzed by nonparametric Mann—Whitney Utest. The percentages of anomalies of the midpiece and of the principal piece were not significantly different between patients and controls. Motility assessed by spermogram was considered functionally uncompromised. In eight patients the percentage of cell alterations of the head (93–100 vs 77.3 ± 6.4%) and the percentage of combined anomalies of the head (78.1–100 vs 60.8 ± 8.5%) were significantly different between patients and controls. In two cases, the percentages established for all head parameters considered were not globally different from those observed in controls. Thus in 8 cases of 10, electron microscopy with quantified analysis supplied valuable evidence about the poor quality of these sperm samples judged as normal under light microscopy and may provide an explanation for their impaired fertilizability. In the two other cases the fact that the sperm appeared to be ultrastructurally normal does not rule out functional sperm pathology. Alternatively, defects in the oocyte may also account for unexplained failures of in vitro fertilization.     

Effects of dexamethasone on the differentiation of membrane structure in cultured astrocytes.

Astrocytic processes investing vascular structures or forming the surface of mammalian brain have large numbers of orthogonally packed aggregates of intramembrane particles, termed "assemblies." Similar particle aggregates are expressed by astrocytes derived from neonatal rat forebrain in secondary culture, but they are much more uniformly distributed across the membranes of the cultured cells. Dexamethasone, a potent glucocorticoid, affects the differentiation of astrocyte membrane structure in two patterns, depending on the rate of proliferation in the culture. When confluent secondary cultures of astrocytes are exposed to 5 microM dexamethasone, the densities of assemblies increase, and in some cells approach the values present in the glial limitans in vivo. However, when rapidly proliferating astrocytes are exposed to dexamethasone during the first week of secondary culture, most of the astrocytes fail to express any assemblies. The rate of astrocyte proliferation is slowed, and a lower cell density is reached during the first 2 weeks of secondary culture in dexamethasone. The suppression of assemblies is transient: as the cultures approach confluence, the proportion of cells expressing assemblies increases to nearly control levels, and the density of assemblies increases to greater than control values in some astrocytes. Certain of the effects of dexamethasone on cultured astrocytes may have relevance for understanding the mechanism(s) of its action in treating cerebral edema.     

钢基Cu-5%Al激光熔覆层颗粒组织分布的定量分析

熔覆层中的颗粒相分布不仅影响材料性能，同时也是研究熔覆过程各种反应机制的主要依据。本文利用图像分析技术，定量分析了Ｑ２３５钢表面Ｃｕ５％Ａｌ激光熔覆层的富铁相颗粒分布情况。发现熔覆过程中在熔池中存在熔体对流环，熔池中的对流带动颗粒运动，是决定熔覆层颗粒分布的主要因素。     

心力衰竭患儿血浆心房利钠肽水平变化及临床意义

目的:探讨心力衰竭患儿血浆心房利钠肽(ANP)的变化及其临床意义。方法:心力衰竭患儿34例,分成3个亚组,Ⅰ度心衰组14例,Ⅱ度心衰组13例,Ⅲ度心衰组7例。分别测定治疗前后血浆ANP水平、血清肌酸激酶同工酶(CK-MB)水平,并作超声心动图检查,观察血浆ANP水平与左室射血分数(LVEF)之间的关系。选取健康儿童20例作为对照组,以了解小儿心力衰竭时ANP、CK-MB变化情况。结果(:1)心力衰竭组ANP、CK-MB水平均明显高于正常对照组,随着心力衰竭程度的加重,血浆ANP水平逐渐增高,与心衰程度呈正相关,与LVEF呈负相关。而CK-MB与心衰程度、LVEF之间均没有相关性。(2)心功能好转后ANP、CK-MB水平均明显下降(P<0.01),LVEF明显增高(P<0.01)。结论:心力衰竭时,血浆ANP水平明显增高,并且与心衰程度、LVEF有较好的关联。     

Development and Optimization of Broadband Acoustic Metamaterial Absorber Based on Parallel–Connection Square Helmholtz Resonators

An acoustic metamaterial absorber of parallel–connection square Helmholtz resonators is proposed in this study, and its sound absorption coefficients are optimized to reduce the noise for the given conditions in the factory. A two–dimensional equivalent simulation model is built to obtain the initial value of parameters and a three–dimensional finite element model is constructed to simulate the sound absorption performance of the metamaterial cell, which aims to improve the research efficiency. The optimal parameters of metamaterial cells are obtained through the particle swarm optimization algorithm, and its effectiveness and accuracy are validated through preparing the experimental sample using 3D printing and measuring the sound absorption coefficient by the standing wave tube detection. The consistency between the experimental data and simulation data verifies feasibility of the proposed optimization method and usefulness of the developed acoustic metamaterial absorber, and the desired sound absorption performances for given conditions are achieved. The experimental results prove that parallel–connection square Helmholtz resonators can achieve an adjustable frequency spectrum for the low frequency noise control by parameter optimization, which is propitious to promote its application in reducing the noise in the factory.     

中性粒细胞与高密度脂蛋白胆固醇比值对急性心肌梗死病人院内主要心血管不良事件的预测价值

目的探讨中性粒细胞与高密度脂蛋白胆固醇( HDL-C)的比值( NHR)对 AMI病人发生院内 MACE的预测价值以及 NHR与 Gensini评分量化的冠状动脉病变严重程度、左室射血分数( LVEF)量化的心脏泵功能的潜在关联。方法纳入 2018年 1月至 2022年 1月东南大学附属中大医院住院并接受冠状动脉造影的 546例 AMI病人。收集人口统计学数据、临床资料及计算 Gensini评分,依据住院期间是否发生 MACE,分为 MACE组( n=105)和非 MACE组( n=441)。使用受试者操作特征曲线(ROC曲线)检验 NHR预测院内 MACE的能力,并确定最佳截断值。使用多因素 logistic回归分析院内 MACE的影响因素,时,采用线性回归分析 NHR对 Gensini评分、 LVEF值的影响,并通过 Graphpad prism绘图进行可视化处理。院内 MACE定义同为:住院死亡、心源性休克、致血流动力学紊乱的恶性心律失常(包括室颤、持续性室速、高度及三度房室传导阻滞)等。结果MACE组的 NHR［13.64(9.89,18.19)］显著高于非 MACE组［7.73(5.83,10.07)］并且 NHR对 AMI病人院内 MACE具有较强的预测价值［AUC:0.84,95%CI:(0.79,0.88),P<0.001］调整混杂因素后,多因素二元,logistic回归分析显示 NHR是 AMI病人院内MACE的独立危险因素［OR:1.29,95%CI:(1.16,1.43),P<0.001］。线性回归分析显示 NHR与 AMI病人 Gensini评分呈显著正相关( P<0.001)与 LVEF呈显著负相关( P<0.001)。结论,本研究证实 NHR是 AMI病人院内 MACE的有力预测指标,是院内MACE的独立危险,因素之一,与 Gensini评分量化的冠状动脉病变严重程度呈显著正相关,与 LVEF量化的心脏泵功能呈显著负相关,可用于早期识别 AMI病人院内 MACE的高危人群,辅助临床诊疗。     

Transiently Transfected Mammalian Cell Cultures: An Adaptable and Effective Platform for Virus-like Particle-Based Vaccines against Foot-and-Mouth Disease Virus

RNA viruses, such as foot-and-mouth disease virus (FMDV), have error-prone replication resulting in the continuous emergence of new viral strains capable of evading current vaccine coverage. Vaccine formulations must be regularly updated, which is both costly and technically challenging for many vaccine platforms. In this report, we describe a plasmid-based virus-like particle (VLP) production platform utilizing transiently transfected mammalian cell cultures that combines both the rapid response adaptability of nucleic-acid-based vaccines with the ability to produce intact capsid epitopes required for immunity. Formulated vaccines which employed this platform conferred complete protection from clinical foot-and-mouth disease in both swine and cattle. This novel platform can be quickly adapted to new viral strains and serotypes through targeted exchanges of only the FMDV capsid polypeptide nucleic acid sequences, from which processed structural capsid proteins are derived. This platform obviates the need for high biocontainment manufacturing facilities to produce inactivated whole-virus vaccines from infected mammalian cell cultures, which requires upstream expansion and downstream concentration of large quantities of live virulent viruses.     

纳米喷雾干燥技术用于生地黄低聚糖微粉的制备工艺研究

目的采用纳米喷雾干燥技术制备载药量高、收率高、吸湿性好的生地黄低聚糖微粉。方法采用B-90纳米喷雾干燥仪制备生地黄低聚糖微粉,采用单因素试验考察后,通过正交试验设计,以平均粒径、收率和吸湿率为评价指标,考察进风口温度、喷雾干燥效率和药液质量分数对制备工艺的影响并优选最佳制备工艺。结果正交试验结果得到最佳制备工艺条件:进风口温度为110℃、喷雾干燥效率为50%、药液质量分数为1.0%,最终得到了载药量为30%、收率为89%、吸湿性良好的生地黄低聚糖微粉,微粉形态稳定。结论采用纳米喷雾干燥技术制备生地黄低聚糖的工艺稳定可行,得到的微粉质量良好,优于传统的喷雾干燥。     

三七总皂苷-丹参酮复合粒子的溶剂沉积法制备及其表征

目的为了解决粒子作为吸入载药系统,药物复方能同步传递的效果,制备出核/壳三七总皂苷-丹参酮复合粒子。方法在三七总皂苷粒子表面利用溶剂沉积法包覆一层丹参酮。分别利用扫描电镜(SEM)、X射线衍射(XRD)、差热分析(DTA)、激光光散射粒径扫描、高效液相色谱(HPLC)对复合粒子进行表征。结果通过上述表征,证明采用溶剂沉积法可成功制备包覆式复合粒子,即丹参酮包裹三七总皂苷复合粒子。结论复合粒子的有效制备为粒子载药系统复方药物的同步传递提供了有力保障,为复方粉雾剂的制备提供了技术支持。