ONE MAJOR PHASE IN HIGH TC Y-Ba-CU-O DETERMINED BY ELECTRON DIFFRACTION

A major phase in high Tc Y-Ba-Cu oxide with zero resistance at 91K and high volume fraction of diamagnetic superconductive phase has been identified by electron diffraction.It appears to be an orthorhombic twinned structure with a=3.89Å,b=3.82Å and c=11.7lÅ.Some defects were observed by TEM.

Effects of Cryopreservation on the Ultrastructure of Human Testicular Sperm

Objective To investigate effects of cryopreservation on changes of the ultrastructure of human testicular sperm and evaluate the efficacy of cryopreserving testicular tissue as a source of sperm for assisted reproduction. Methods Testicular biopsy tissues were obtained from infertile patients （n=12） with obstructive azoospermia and cryopreserved. Testicular sperm motility was observed after in vitro culture procedure. The ultrastructure of testicular sperm （n=6） was examined by transmission electron microscope. Results After cryopreservation, 10 biopsy tissues frozen revealed motile sperm, and 2 samples showed non-motile sperm. Some testicular sperm in frozen-thawed group had normal morphology in fine structures. Sperm head in frozen-thawed tissue showed a proportion of nuclei with more electron-dense granules of chromatin. In a few frozen-thawed sperm heads, formation of vesicles and degeneration were observed. The frozen-thawed testicular sperm frequently showed swollen or/and ruptured of the plasma membrane and acrosome membranes. Conclusion Cryopreservation of testicular tissue is simple and efficacious for testicular sperm extraction. And the freezing-thawing procedure of testicular tissue causes damage to ultrastructural morphology of human testicular sperm.

Sodium iodate-induced retina degeneration observed in non-separate sclerochoroid/retina pigment epithelium/retina whole mounts

Background:Sodium iodate(SI)is a chemical widely applied to induce retina degeneration in animal models.SI treatment caused formation of rosettes/folds in the outer nuclear layer(ONL)of the rat retina,but it was previously unclear whether SI also forms rosettes in mice.In addition,SI induced retina degeneration was never addressed in non-separate sclerochoroid/retina pigment epithelium/retina whole mount.Here we displayed features of retina degeneration including rosette formation in mice and developed a morphological analytic assessment using sclerochoroid/retina pigment epithelium/retina whole mounts.Methods:SI was intraperitoneally injected in Sprague-Dawley(SD)rats and C57BL/6J mice using a single dose(50 mg/kg)or with a dose range(10 to 50 mg/kg)in BALB/C mice.Rat retinas were investigated up to 2-week post-injection by histology and whole mounts,and mouse retinas were investigated up to 3-week post-injection by histology,fluorescent staining of sections and/or sclerochoroid/retina pigment epithelium/retina whole mounts for the morphological evaluations of the SI-induced retina damage.Results:SI-induced retina damage caused photoreceptor(PR)degeneration and rosettes/folds formation,as well as retina pigment epithelium degeneration and inward migration.It displayed mixed nuclei from choroid to PRs,due to layer disorganization,as shown by single horizontal images in the sclerochoroid/retina pigment epithelium/retina whole mounts.Measurement of the PR rosette area induced by SI provided a quantitative,morphological evaluation of retina degeneration.Conclusions:The method of non-separate sclerochoroid/retina pigment epithelium/retina whole staining and mount allows us to observe the integral horizontal view of damage from sclera to PR layers,which cannot be addressed by using sectioned and separate whole mount methods.This method is applicable for morphological evaluation of retina damage,especially in the subretinal layer.

Nano-Crystalline Diamond Films Grown by Radio-Frequency Inductively Coupled Plasma Jet Enhanced Chemical Vapor Deposition

Radio-frequency inductively coupled plasma jet is utilized to grow diamond films to combine the advantages of clean deposition environment and large deposition area. Before diamond growth, the simulation of deposition environment is studied to understand the flow field and the properties of the plasma. The optical emission spectra fOES） are also applied to diagnose the rf plasma. The plasma density ne and the electron temperature Te deduced from the data measured by OES are about 1.0 × 1014 1/cm3 and 1.4 eV, which are in good agreement with the data calculated in the simulation. Based on the data from both simulation and measurement, the optimized growth parameters are determined to grow diamond films. Nano-crystalline diamond with cauliflower-like morphology is obtained. The crystalline feature and impurity of as-grown films are also studied.

A piece of new HRTEM lattice image evidence for P2_1ca hypersthene of Chengde, China

Traditionally the space group of orthopyroxenes is catalogued into Pbca.Nevertheless,in 1974,Smyth found out that the bronzite from one lunar rock is of P21ca based on thepresence of the 0 kl diffractions with k-odd.Sequently it was reported that the ortho-pyroxenes from certain meteorites and a lunar soil are of P21ca.Some

Unique Ultrastructural Alterations in the Placenta Associated With Macrosomia Induced by Gestational Diabetes Mellitus

Objective:To investigate the morphological and ultrastructural alterations in placentas from pregnancies with gestational diabetes mellitus(GDM)–induced macrosomia,term nondiabetic macrosomia,and normal pregnancies.Methods:Sixty full-term placentaswere collected,and clinical data alongwith informed consent were obtained from pregnant womenwho underwent regular visit checks and delivered their newborns in Northwest Women’s and Children’s Hospital between May and December 2022.Placentas were divided into three equal groups:normal pregnancy(control group),nondiabetic macrosomia group,and macrosomia complicated with GDM(diabetic macrosomia)group.Gross morphological data of placentas were recorded,and placental samples were processed for examination of ultrastructural and stereological changes using transmission electron microscopy.Analysis of variance and chi-squared test were used to examine the differences among the three groups for continuous and categorical variables,respectively.Results:The baseline characteristics of mothers and neonates did not differ across the three groups,except for a significantly higher birth weight in the diabetic macrosomia group(4172.00±151.20 g vs.3192.00±328.70 g,P<0.001)and nondiabetic macrosomia group(4138.00±115.20 g vs.3192.00±328.70 g,P<0.001)comparedwith control group.Examination of the placentas revealed that placental weight was also highest in the diabeticmacrosomia group comparedwith control group(810.00±15.81 g vs.490.00±51.48 g,P<0.001)and nondiabetic macrosomia group(810.00±15.81 g vs.684.00±62.69 g,P<0.001),but the ratio of neonatal birth weight to placental weight(BW/PW)was significantly lower in the diabetic macrosomia group compared with that in the control group(5.15±0.19 vs.6.54±0.63,P<0.001)and nondiabetic macrosomia group(5.15±0.19 vs.6.09±0.52,P<0.001)group.In contrast,the BW/PW ratio in nondiabetic macrosomia did not differ significantly from that in the control group.Distinct ultrastructural changes in terminal villi and stereological alterations in microvilli were observed in the diabetic macrosomia group,including changes in the appearance of cytoplasmic organelles and the fetal capillary endothelium and thickness of the vasculo-syncytial membrane and basal membrane.Conclusion:Significant ultrastructural and stereological alterations were discovered in the placentas from pregnant women with macrosomia induced by GDM.These alterationsmay be the response of the placenta to the hyperglycemia condition encountered during pregnancies complicated with GDM.