The effects of repeated freezing and thawing on bovine sperm morphometry and function.

Refreezing the remaining genetic resources after in vitro fertilization (IVF) can conserve genetic materials. However, the precise damage inflicted by repeated freezing and thawing on bovine sperm and its underlying mechanism remain largely unexplored. Thus, this study investigates the impact of repeated freeze-thaw cycles on sperm. Our findings indicate that such cycles significantly reduce sperm viability and motility. Furthermore, the integrity of the sperm plasma membrane and acrosome is compromised during this process, exacerbating the advanced apoptosis triggered by oxidative stress. Additionally, transmission electron microscopy exposed severe damage to the plasma membranes of both the sperm head and tail. Notably, the "9 + 2" structure of the tail was disrupted, along with a significant decrease in the level of the axonemal protein DNAH10, leading to reduced sperm motility. IVF outcomes revealed that repeated freeze-thaw cycles considerably impair sperm fertilization capability, ultimately reducing the blastocyst rate. In summary, our research demonstrates that repeated freeze-thaw cycles lead to a decline in sperm viability and motility, attributed to oxidative stress-induced apoptosis and DNAH10-related dynamic deficiency. As a result, the utility of semen is compromised after repeated freezing.

A new type of electron microscope rapid collection device for atmospheric particles and its application cases.

A device for collecting atmospheric particulates matter for on-line electron microscopy was designed and manufactured by using 3D modeling and printing technology. The device was used to collect atmospheric particulates matter in Xining city of Qinghai province for seven consecutive days and used to collect atmospheric particulates matter in Jinan city of Shandong province for 30 consecutive days. And the samples were analyzed by electron microscopy. Through it can obtain ultra structure and size distribution information of atmospheric particulates matter. The experimental results reflected the distribution of atmospheric particulate matter in real time. The on-line acquisition device for electron microscopy is practical, fast, and convenient, which greatly shortens the sampling period and can be carried to any place outdoors for real-time sampling. The morphological structure and particle size distribution of atmospheric particles in sampling area was observed by electron microscope. The device has reference value to the study of PM2.5 and PM10 in atmosphere and air pollution. This acquisition device is convenient for the detection of sample by electron microscopy. It can further expand and simplify the sampling technology of large-scale instruments and equipment. This new method of real-time monitoring of air pollution is worth popularizing and applying.

Zinc regulates the hydraulic response of maize root under water stress conditions.

Zinc (Zn) is involved in plant growth and stress resistance and is known to increase crop yield. Here, we investigated the effect of Zn on water absorption in the roots of maize (Zea mays L.), a crop which is sensitive to Zn deficiency, during water stress conditions. Seedlings of the maize variety "Zhengdan 958" were cultivated with 0.1 or 6 µM ZnSO4·7H2O. To simulate drought stress, three-week-old seedlings were exposed to 15% polyethylene glycol (PEG). Root growth parameters, root antioxidant enzyme activity, root hydraulic conductivity, root aquaporin gene expression, root and leaf anatomy structure, leaf water potential, chlorophyll content, leaf area, and gas exchange parameters were measured. Under water stress, moderate Zn treatment promoted root growth; maintained root and leaf anatomy structural integrity. Moderate Zn significantly increased roots hydraulic conductivity (51%) and decreased roots antioxidant enzyme activity (POD: -11.1%, CAT: -35.1%, SOD: -3.1%) compared with low-level Zn under water stress. The expression of ZmPIP1;1, ZmPIP1;2, and ZmPIP2;2 was significantly higher with moderate Zn treatment than that of low-level Zn treatment. The leaf water potential, chlorophyll content, leaf area, and gas exchange parameters with moderate Zn treatment increased significantly under water stress compared with low-level Zn treatment. The moderate concentration of Zn improved root hydraulic conductivity in maize and increased resistance to simulated drought conditions by maintaining root structural integrity, decreasing antioxidant enzyme activity, and increasing aquaporin gene expression. Moderate Zn application increased root water absorption and leaf transpiration, thereby maintaining maize water balance under water stress conditions.

Effects of low frequency pulsed electromagnetic field on stomach blood circulation and ultra microstructure of stress ulcer in rats / 医疗卫生装备

Objective To determine non-thermal biological effect of low frequency pulsed electromagnetic field (LFPEF)on the stomach blood circulation and ultra microstructure of rat stress ulcer. Methods Thirty-six Sprague-Dawley rats were assigned to three equal groups:control,ulcer without interference group(UW)and ulcer exposure groups(UE).The rats stress ulcer models were constructed with the combination method of soak and bind in the low-pressure and hypoxia circumstance. Based on the singlechip,a LFPEF generator with adjustable frequency, amplitude and duty ratio was developed. Then the stomachs of the rats were exposed to the LFPEF generator 3 hours per day.On days 1,3,5 and 7,the blood circulation of the stomach was analyzed by the content of the serum NO and contrast ultrasonography.In addition,the ulcer tissue was taken out for section-staining. Finally, the pathological change of the stomach ultra microstructure was observed under a light microscope. Results On different days, the contents of the serum NO and microbubble concentration of UE group were significantly higher than those of the UW group(P<0.05). The pathological observation showed that the restoration of the gastric tissue in UE group was faster than that in the UW group(P<0.05).Conclusion LFPEF with certain proper parameter could improve the gastric tissue blood circulation and accelerate the stress ulcer restoration. [Chinese Medical Equipment Journal,2018,39(5):35-38]

A study on thyroid injury in rats with sepsis / 中华急诊医学杂志

Objective To explore the effects of sepsis on the ultrastructure and function of thyroid in rats.Methods This study was performed in the Animal Department of Fujian Medical University,the Key Laboratory of Fujian Provincial Cardiovascular Institute and the Electron.Microscopic Department of Fujian Medical University.Thirty-two pathogen-free male Sprague-Dawley rats weighing 180-220 g selected,and were randomly (random number) divided into control group (C group,n =8),12 hour group (n =8),24 hour group (n =8) and 36 hour group (n =8).The 12 h group,24 h group and 36 h group were established to be sepsis groups.The sepsis model was made by cecal ligation and puncture (CLP).The samples of blood and thyroid tissue of rats in 12 h group were taken 12 hours after modeling,and then the same procedure was done in the rats of 24 h group and 36 h group separately 24 hours and 36 hours after modeling.Blood serum was obtained by centrifugation to detect the thyroid function using measurement of different of kinds of hormones (T3,T4,fT3,fT4,TSH).Thyroid tissue was available to determine the expression of caspase-3,cell apoptosis and change of ultra-microstructure.Raw data were analyzed using SPSS19.0 software.Caspase-3 grey value was determined by Image J software.Thyroid hormone levels were presented as mean ± standard deviation.The differences in levels of different kinds of thyroid hormone among all the groups were determined by one-way ANOVA.TUNEL positive staining and caspase-3 expression were presented as median (P25,P75).Results Compared to the control group,the T4 decreased significantly (P＜0.05) in the 12 h group,the 24 h group and the 36 h group,both the tT3 and the fT4 decreased significantly in the 24 h group and the 36 h group (P ＜0.05),and the T3 decreased significantly in the 36 h group (P ＜ 0.05).The expression of caspase-3 in the 24 h group was higher than that in the C group (P ＜ 0.05).There was significant difference in rate of celt apoptosis in thyroid tissue among those four groups,and both the 24 h group and the 36 h group had higher rate of cell apoptosis than the C group significantly (P ＜0.05).In those sepsis groups,a series of pathological ultrastructural changes were found in thyroid follicular epithelial cells as following:the nucleus became smaller and more distinctly stained,and quite a few vacuoles were visualized in cell.Furthermore,the cell membrane was broken,and nuclei showed pyknosis.Conionclus In sepsis rats,the significant changes of different kinds of thyroid hormone in serum are similar to those found in the thyroidal illness syndrome,the expression of caspase-3 and cell apoptosis in thyroid tissue increase,and pathological change of thyroid follicular epithelial cells can be observed under electron microscopy.

Influences of Xuebijing injection on organs' ultra-microstructure in septic shock rats / 中国中西医结合急救杂志

Objective To investigate the influences of Xuebijing injection on organs' ultra-microstructure in septic shock rats. Methods Fifteen male Sprague-Dawley (SD) rats of clean grade were selected. According to the method of random digits table, all of them were divided into three groups: sham operation group, model group and Xuebijing treated group, 5 rats being in each group. Cecal ligation and puncture (CLP) was adopted to reproduce abdominal cavity infection leading to sepsis model formation. While the rats in sham operation group just underwent abdominal median incision, abdominal exploration and closure of abdominal wall after flipping retrocecal region. In the Xuebijing treated group, within 1 hour after the operation, Xuebijing injection (4 mL/kg) was transfused through the catheter inserted in the femoral vein, and then normal saline (2 mL·kg-1·h-1) was continuously transfused until the rat being sacrificed. In the sham operation group and model group, equal volume of normal saline was given after operation. The blood pressure of all the rats was monitored continuously by a pressure device connected with a catheter inserted in the right carotid artery. The rats were observed for 12 hours, afterwards they were sacrificed, the samples of heart, lung, kidney and liver were taken, and their ultrastructural changes were observed under an electron microscope. Results The blood pressure of sham operation group was decreased a little with time extension, but within normal limits. The mean arterial pressure (MAP) of model group and Xuebijing treated group developed into a state of sepsis shock at 9 hours and 10 hours after operation respectively, and MAP were lower than 70 mmHg (1 mmHg=0.133 kPa). The MAP levels of model and Xuebijing groups at 11 hours after operation were lower significantly than those of sham operation group (mmHg:58.7±7.0, 58.7±8.3 vs. 91.0±8.2, both P0.05). The results of the observation with electron microscope:the structures of heart, lung, liver and kidney in sham operation group were basically normal;all the organs of model group appeared different degrees of structural damage. Compared with model group, the injury of heart and lung in Xuebijing treated group was milder, especially, the changes of cellular mitochondria were obvious;however, there was no significant difference in injury of kidney and liver between the model and Xuebijing treated groups. Conclusion Xuebijing injection can play a certain role in stabilizing the circulatory system in rats with septic shock, and can possibly ameliorate the heart and lung damage caused by infection and shock.

Effects of high temperature stress on plasma membrane permeability and chloroplast structure of Huperzia serrata / 中草药

Objective: Huperzia serrata, whose growth is limited by high temperature, is a rare medicinal plant with the treatment function for Alzheimer's disease (AD). To research the effect of high temperature on the structure and function of cell membrane and chloroplast, and to provide the evidence for production practices. Methods: H. serrata was processed at 25, 30, 35, and 40°C, respectively, then the content changes of malondial dehyde (MDA) and conductivity rate, and the content changes of total chlorophyll, chlorophyll a, chlorophyll b, and chlorophyll a/b values were measured. The changes of the chloroplast ultra microstructure were observed under the transmission electron microscope (TEM). Results: The changes of MDA and conductivity rate in the process at 35 and 40°C were significantly higher than those of the control group; After processed at 40°C for 4 d, the total chlorophyll was decreased significantly, and became the lowest on the day 6, just was 58% compared to the control group; the change trends to the contents of chlorophyll a, chlorophyll b, and total chlorophyll were similar; TEM observation revealed that after processed at 35°C for 4 d, the chloroplast structure appeared deformation, and after processed at 40°C for 4 d, the chloroplast structure subjected obvious destruction capsule fuzzy, fracture in different degrees, thylakoid in disorder, matrix lamellar irregular, and so on. Conclusion: According to the changes of physiological index, ultramicroscopic structure, and external morphology of chloroplast, the suitable temperature for H. serrata is 25-30°C, 40°C is the limited temperature, causing death after 4 d stress, and 35°C has obvious impact on the growth, long-time stress in 35°C could also cause plant deaths.

Neuroprotection of n-Butanol Extract from Roots of Potentilla anserina on Hypoxic Injury in Primary Hippocampal Neurons / 中草药·英文版

Objective To investigate the protective effect of n-butanol extract from the roots of Potentilla anserina (NP) on hypoxic hippocampal neurons in neonatal rats.Methods Primary cultured hippocampal neurons were pretreated with different concentration of NP (0.25,0.0625,and 0.0156 mg/mL) before incubation in a low oxygen (0.1％) environment for 4 h.Cell viability was evaluated by Trypan blue staining assay.Lactate dehydrogenase (LDH) released by neurons into the medium was measured.The activity of superoxide dismutase (SOD) in cell cytosol was determined using nitroblue tetrazolium.Morphological changes and mitochondrial function were observed by transmission electron microscopy.Results Hypoxic injury could decrease the cells viability of neuron,enhance LDH release (P ＜ 0.05),decrease SOD activity,and increase mitochondrial injury.Pretreatment with NP significantly increased cell viability,decreased LDH release (P ＜ 0.05),promoted SOD activity (P ＜ 0.05),and remarkably improved cellular ultra-microstructure compared with the model group.Conclusion NP could protect the primary hippocampal neurons from hypoxic injury by attenuating mitochondrial cell death.

Ultrastructure change of conjunctiva and fascia tissue of conjunctivochalasis / 中华实验眼科杂志

Background Bulbar conjunctiva tissue appears to be thinning,elasticity declined,tension reduced and fascia atrophied in conjunctivochalasis.Histopathological examination of conjunctivochalasis shows decrease of elastic fibers and melt of collagen fibers.But there are fewer studies on the ultrastructure of conjunctiva of conjunctivochalasis up to now.Objective This study was to investigate the ultrastructure change of conjunctiva tissue in conjunctivochalasis.Methods Five loose conjunctiva samples of conjunctivochalasis and 5 normal conjunctival tissue samples were collected and ultra-microstructure changes of these samples were observed under the transmission electron microscope.Results The number of fibroblasts in conjunctivochalasis lamina was progressively decreased.The shape of fibroblasts was long and fusiform.Somatic synapse was slim.Nucleus-cytoplasm ratio was increased.Disorder,scattered and broken of the collagen fibril were seen,and some areas were dissolved or lacunae.Normal conjunctival fibroblasts were oval or polygonal,with wieners and long somatic synapse,and intercellular matrix was full of collagen fibril and dense arranged fibers.Fibroblasts in fascia of eonjunctivochalasis were linear,and collagen fibril was seriously defected.Fascia fibroblasts of normal bulbar conjunctiva were spindleshaped and bigger than conjunctivochalasis fibroblasts.There were full of collagen fibrils in intercellular matrix.Conclusions The collagen fibril is decreased and fibroblast cells are degenerated in lamina and fascia of conjunctivochalasis.

Changes of platelet activation markers and platelet ultra-microstructure in the patients with acute myocardial infarction / 中华急诊医学杂志

Objective To investigate the expressions of platelet activation-dependent granule membrane protein and platelet-derived growth factor receptor-αB, and the ultra-microstructure changes of platelets in patients with acute ST-segment elevation myocardial infarction(STEMI). Method The expressions of platelet activationdependent granule of glycoprotein (CD62P)and platelet derived growth factor receptor αβ subtype (PDGFR-αβ)of platelets in peripheral blood in 36 patients with acute ST-segment elevation myocardial infarction(STEMI) hospitalized and another 34 healthy subjects over the same period (control group) were investigated by flow cytometry and data were analyzed. The changes of ultra microstructure and activity of blood platelets in those patients and control group were observed under the scanning electron microscope. Results The expressions of CD62P and PDGFR-αβin patients with STEMI group before treatment were (3.65 ± 1.87) % and (0.43 ± 0.39) %, respectively, and those after treatment were (0.96 ± 0.79) % and (0.28 ± 0. 24) %, respectively, whereas those in control group were (0.67 ± 0.35) % and (0.27 ± 0.22) %, respectively, which were much lower in control than those in patients with STEMI before treatment (P ＜ 0.01 or P ＜ 0.05) respectively. There were statistically significant differences in the expressions of CD62P and PDGFR-αβ in patients group between pre-treatment and posttreatment (P ＜0.01 or P ＜0.05), respectively. Obvious ultra-microstructure changes of platelet surface in patients with STEMI group were observed. Conclusions Due to platelet activation in AMI, the expressions of CD62P can be used as effective indicators for monitoring coronary heart disease, and the PDGFR-αβ can be used as a reference indicator. The platelet surface ultra-microstructure changes during platelet activation in patients with AMI can be found by scanning electron microscopy.