[Determination of dimethyl oxalate and diethyl oxalate in workplace air by high performance liquid chromatography].

Objective: To establish a high performance liquid chromatography method for the simultaneous determination of dimethyl oxalate (DMO) and diethyl oxalate (DEO) in workplace air. Methods: From January 2022 to January 2023, air samples were collected by silica gel tubes, desorbed by acetonitrile, separated by C18 chromatographic column, detected by photo-array detector, and retention time was used to characterize and peak area was used to quantify at 210 nm wavelength. Results: The linear relationships of DMO and DEO were good, r>0.999. The detection limits of DMO and DEO were 0.39 and 0.52 µg/ml, respectively. The quantitative limit was 1.28 µg/ml for DMO and 1.72 µg/ml for DEO. Average desorption efficiency for DMO was 82.40%-92.72%, and DEO was 94.13%-97.69%. The intra-assay precision of DMO was 1.87%-6.18%, and DEO was 2.25%-3.31%. Inter-assay precision of DMO was 3.29%-5.73%, and DEO was 1.38%-2.94%. Average sampling efficiencies were 100% for both DMO and DEO. Breakthrough capacity of DMO was 37.61 mg (200 mg solid adsorbent), DEO was >28.11 mg (200 mg solid adsorbent). Samples should be stored at 4 ℃ for at least 7 days. Conclusion: This method is easy to operate and has strong practicability. All indicators meet the requirements of the specification, and it is suitable for the simultaneous determination of DMO and DEO in the workplace air.

[Investigation of occupational noise exposure and hearing loss among automobile manufacturing workers].

Objective: To investigation the situation of occupational noise exposure and hearing loss among workers in automobile manufacturing enterprise during 2017-2019 in Wuhan. Methods: Workers in automobile manufacturing who underwent physical examination in Wuhan Hospital for the Prevention and Treatment of Occupational Diseases from 2017 to 2019 were included as subjects in the cross-sectional survey. Questionnaire survey, noise detection and pure tone threshold test were used. Excluding individuals with working time less than 3 years and information deficiency, 3 948 individuals were finally included in the study. Results: Among 3 948 workers, 128 workers had hearing loss and the rate of hearing loss was 3.24%, among which 101 workers had high-frequency hearing loss and 27 workers were diagnosed as occupational noise deafness. The prevalence of hearing loss among workers previously exposed to noise was significantly higher than that without prior exposure (12.10%, 0.96%, P<0.05) . The prevalence of hearing loss among workers with occupational noise exposure <80 dB (A) , 80~<85 dB (A) and ≥85 dB (A) was 1.83%, 2.69% and 5.09%, respectively. The prevalence of high frequency hearing loss was 1.60%, 2.05% and 3.71%, respectively. The prevalence of occupational noise deafness was 0.23%, 0.64% and 1.38%, respectively. The prevalence of hearing loss and high frequency hearing loss among workers exposed to different occupational noise was statistically significant (P<0.05) , while the prevalence of occupational noise deafness was not statistically significant (P>0.05) . There were statistically significant differences in the prevalence of hearing loss (2.88%, 4.45%) and occupational noise deafness (0.46%, 1.41%) between those who used protective equipment and those who did not (P<0.05) . Compared with workers exposed to occupational noise <80 dB (A) , workers exposed to occupational noise ≥85 dB (A) had A 3.16-fold increased risk of hearing loss (OR=3.16, 95%CI: 1.44~6.95, P<0.05) . Compared to workers using hearing protective equipment, the risk of hearing loss (OR=1.96, 95%CI: 1.25~3.06, P<0.05) and occupational noise deafness (OR=3.46, 95%CI: 1.51-7.96, P<0.05) significantly increased among those without using hearing protective equipment. Conclusion: The risk of hearing loss in automobile manufacturing workers is significantly associated with occupational noise exposure and the use of hearing protective equipment. Good hearing protection may reduce the risk of occupational noise-induced hearing loss and occupational noise deafness.

[Analysis of clinical early warning informations of severe preeclampsia before onset].

Objective: To explore the early warning informations of severepre-eclampsia before onset. Methods: The study was an observational case-control study. The study group consisted of 77 single-pregnancy preeclampsia pregnant women and the control group took 154 normal cases who were delivered to Tianjin Fifth Central Hospital (Peking University binhai Hospital) from January 2014 to December 2017 in the perinatal care referral system in Tianjin. To analyze changes in clinical indicators before the onset of severe pre-eclampsia with statistical methods. Results: Prehypertension, weight gain>0.85 kg/week, fetal growth restriction, edema and decline of plasma albumin, thrombocytopenia, poor compliance, perinatal examinations and examinations in tertiary hospitals were associated with severe pre-eclampsia (P<0.001). Multivariate regression analysis showed that the risk factors of severe preeclampsia were pre-hypertension, weight gain>0.85 kg/week, edema, thrombocytopeniaand poor compliance. The increase in the number of prenatal examinations in tertiary hospitals was a protective factor for severe preeclampsia. Conclusion: Prehypertension, weight gain during pregnancy (>0.85 kg/week), edema, thrombocytopenia, and poor compliance were warning informations of severe pre-eclampsia, and the increased number of prenatal examinations in tertiary hospitals was a protective factor for severe pre-eclampsia.

Effects of N-carbamylglutamate and L-arginine on gonadotrophin-releasing hormone (GnRH) gene expression and secretion in GT1-7 cells.

Recent studies have shown that N-carbamylglutamate (NCG) and arginine (ARG) supplementation improves reproductive performance in livestock. The objectives of the present study were to evaluate the effects of NCG and ARG on GT1-7 cell gonadotrophin-releasing hormone (GnRH) secretion, gene expression and cell proliferation. GT1-7 cells were treated in vitro with different concentrations of NCG (0-1.0mM) or ARG (0-4.0mM) in serum-free medium for 12 or 24h. For GnRH secretion and cell proliferation, GT1-7 cells were more sensitive to NCG than ARG. NCG treatment after 12h increased cell numbers and inhibited GnRH secretion in a dose-dependent manner (P<0.05), although there was no significant effect of NCG on these parameters after 24h culture. ARG treatment decreased GnRH secretion after 24h (P<0.05), whereas it had no effect after 12h. GT1-7 cells express GnRH, Kiss-1 metastasis-suppressor (Kiss1), G-protein coupled receptor 54 (GPR54), neuronal nitric oxide synthase (nNOS) and estrogen receptor α (ERα) genes. High concentrations of NCG (1.0mM) and ARG (4.0mM) inhibited (P<0.05) GnRH and nNOS mRNA abundance in GT1-7 cells. ARG treatment decreased Kiss1 and increased ERα mRNA abundance. Thus, high concentrations of NCG (1.0mM) and ARG (4.0mM) may act both directly and indirectly to regulate GnRH neuron function by downregulating genes related to GnRH synthesis and secretion to slow GnRH production while stimulating GT1-7 cell proliferation.

[Evaluation of the tear film function in diabetic patients using the Keratograph 5M].

Objective: To evaluate the tear film function of diabetic patients using the Keratograph 5M and to analyze its related factors. Methods: Case-control study. A total of 89 inpatients (174 eyes) diagnosed with diabetes in the Department of Endocrinology at our hospital were recruited. According to the fundus fluorescein angiography results, subjects were divided into two groups, diabetic retinopathy (DR) group and none-DR group. All subjects were examined for duration of diabetes, glycosylated hemoglobin, creatinine, 24-hour urinary protein, and 24-hour urinary microalbumin/urinary creatinine, and by electromyography. The Keratograph 5M was used to obtain the first and average tear film break-up time (BUTf and BUTav), tear meniscus height, the upper and lower meibomian gland loss scores. The data were analyzed by SPSS. Results: Compared to the non-DR group, the BUTf and the BUTav in the DR group were shorter [(8.42±4.71) s vs. (10.24±5.32) s, (11.20±5.25) s vs. (12.67±5.52) s; P=0.000]. There was no significant difference in the tear meniscus height between the three groups (P=0.067). The tear meniscus height were negatively related with glycosylated hemoglobin, and not related with duration of diabetes, 24-hour urinary microalbumin/urinary creatinine, creatinine, 24-h urinary protein, and electromyography results. As the duration of diabetic longer, the upper and lower meibomian gland loss scores added(Z=19.514, 15.342, P<0.05). Patients with EMG abnormal, the lower meibomian gland loss scores added(Z=-2.312, P<0.05). Conclusions: The Keratograph 5M can directly evaluate the tear film condition of diabetic patients.Diabetic patients with retinopathy and higher glycosylated hemoglobin tend to suffer tear film dysfunction. (Chin J Ophthalmol, 2018, 54:762-766).

[Influencing factors for reproductive health of female workers in petrochemical industry].

Objective: To investigate the reproductive health status of female workers in petrochemical industry, and to provide a reference for improving reproductive health status and developing preventive and control measures for female workers in petrochemical industry. Methods: A face-to-face questionnaire survey was performed from January to October, 2016. The Questionnaire on Women's Reproductive Health was used to investigate the reproductive health of female workers in petrochemical industry. The multivariate logistic regression model was used to identify the influencing factors for reproductive health of female workers in petrochemical industry. Results: Among the 7485 female workers, 1 268 (40.9%) had abnormal menstrual period, 1 437 (46.4%) had abnormal menstrual volume, 177 (28.5%) had hyperplasia of mammary glands, and 1 807 (24.6%) had gynecological inflammation. The reproductive system diseases in female workers in petrochemical industry were associated with the factors including age, marital status, education level, unhealthy living habits, abortion, overtime work, work shift, workload, video operation, occupational exposure, positive events, and negative events, and among these factors, negative events (odds ratio[OR]= 1.856) , unhealthy living habits (OR=1.542) , and positive events (OR=1.516) had greater impact on reproductive system diseases. Conclusion: Many chemical substances in the occupational environment of petrochemical industry can cause damage to the reproductive system, which not only affects the health of the female workers, but also poses potential threats to the health of their offspring. Occupational exposure, unhealthy living habits, overtime work, and work shift have great influence on reproductive system diseases in female workers.

[Investigation of neck and shoulder pain among workers in an automobile plant].

Objective: To investigate the prevalence and risk factors of neck and shoulder pain (NSP) among automobile manufacturing workers and to provide a theoretical basis for prevention of NSP. Methods: From November 5 to November 19, 2017, a total 446 works who had worked for more than one year were recruited from an automobile plant by cluster sampling method. Chi square test and unconditional logistic regression were used to exam the relation between influencing factors and NSP. Results: The annual prevalence rate of NSP was 34.8%. Multifactor regression analysis showed that age、work fatigue、department staff shortages、lifting heavy objects in awkward positions、neck flexion foreword and prolong sitting position work were the risk factors of NSP (OR=2.18, 95%CI:1.49~3.18; OR=4.52, 95%CI:1.27~16.00; OR=1.66, 95%CI:1.04~26.68; OR=2.10, 95%CI:1.16~3.81; OR=2.25, 95%CI:1.39~3.66; OR=2.42, 95%CI:1.06~5.56) and work break was the benefit factors of NSP (OR=0.58, 95%CI:0.36~0.94) . Conclusion: The annual prevalence rate of NSP among automobile manufacturing workers was high. Lifing heavy objects、awkward working positions and unreasonable work arrangement were the major risk factors of NSP, and work break can effectively reduce the risk of NSP. Effective ergonomic intervention should be carried out to prevent the occurrence of NSP.

[Correlation between social support and quality of life in patients with breast cancer at different periods of treatment].

Objective: To analyze the differences between the social support for breast cancer patients and healthy female, and to explore the correlation between social support and quality of life (QOL) in the patients. Methods: From January 2013 to December 2014, 101 patients with operable breast cancer treated at Xinyu City People's Hospital were recruited as the experimental group. They completed questionnaires in the preoperative, postoperative chemoradiotherapy and rehabilitation periods, respectively.101 healthy female volunteers recruited from the community were included as control group, whose age and level of education were matched with those of the experimental group.The general questionnaire including basic information, disease conditions and other projects, perceived social support scale (PSSS), quality of life of breast cancer patients (FACT-B) were applied to evaluate the general situation, social support and QOL of the subjects. The differences in PSSS scores between the experimental and control groups were compared. The correlation between PSSS score and FACT-B score in the experimental group was analyzed. SPSS 18.0 software was used for statistical analysis. Results: The general situations of the experimental and control groups were comparable (all P>0.05). The rates of the total social support score ≥50 in the experimental and control groups were not significantly different (93.6% vs. 94.7%, P=0.067). Compared with that of the control group (23.2±4.8), the scores of family support in the experimental group in preoperative, postoperative chemoradiotherapy and rehabilitation periods were statistically higher (25.6±3.2, 24.2±4.2 and 24.0±3.4, respectively, P=0.034). The social support scores of patients with different demographic characteristics were different. Among the demographic characteristics, years of education and place of residence had the largest impact. The scores of social support in patients with longer education years and living in the urban area were higher than those with shorter education years and living in the rural areas (P<0.001). The scores of QOL among preoperative, postoperative chemoradiotherapy and rehabilitation periods in the experimental group were significantly different (all P<0.05). The patients gained the highest score of QOL in the preoperative period (110.7±5.1) and the lowest in the postoperative chemoradiotherapy period (95.3±18.1). The QOL of patients in the experimental group in preoperative, postoperative chemoradiotherapy and rehabilitation periods were all positively correlated with the overall social support (all P<0.01). Conclusions: The QOL of breast cancer patients at different periods of treatment is positively correlated with the social support. The quality of life can be enhanced by improving the social support for the patients.

[Effect of exendin-4 on lipid deposition in skeletal muscle of diet-induced obese mice and its underlying mechanism].

Objective: To investigate the effect of exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist, on reducing lipid deposition and improving insulin resistance in skeletal muscle and the underlying mechanisms in high-fat diet (HFD)-induced obese mice. Methods: Twelve male C57BL/6J mice were challenged with HFD for 12 weeks to induce obesity and then randomly divided into two groups: exendin-4 group (intraperitoneal injection of 24 nmol·kg-1·d-1 exendin-4 for 4 weeks) and HFD group (intraperitoneal injection of normal saline for 4 weeks), with 6 mice in each group. Additional 6 mice were also selected as control group. Body weight, fasting blood glucose were recorded. Serum triglyceride (TG), total cholesterol (TC), insulin and skeletal muscle triglyceride levels were measured by enzyme-linked immunosobent assay (ELISA). Oil red O staining was used for morphologic changes of frozen sections from skeletal muscle. The protein levels of lipid metabolic pathway mediated by AMP-activated protein kinase (AMPK) and insulin signailing pathway were determined by Western blot. Results: Compared with mice in HFD group, exendin-4 significantly decreased body weight[(37.68±1.80) vs (46.03±5.00) g, P<0.025], fasting blood glucose[(5.40±0.33) vs (7.65±1.92) mmol/L, P<0.025], serum TG[(37.78±7.14) vs (80.76±34.22) mg/dl, P<0.025], TC[(180.13±18.75) vs (217.57±22.52) mg/dl, P<0.025], insulin[(0.58±0.01) vs (1.67±1.23) ng/ml, P<0.025]and skeletal muscle TG levels[(9.84±1.08) vs (19.35±7.44) mg/g, P<0.025]of obese mice. Oil red O staining revealed that exendin-4 alleviated the accumulation of larger lipid droplets in skeletal muscle. The protein expressions of lipolysis and lipid oxidation mediated by AMPK and insulin signailing pathway were up-regulated, and the protein expressions of lipogenesis mediated by AMPK were down-regulated after intervention of exendin-4. Conclusion: Exendin-4 reduces lipid deposition and insulin resistance in skeletal muscle of HFD-induced obese mice via activating AMPK and up-regulating insulin signailing pathway.

In vitro and in vivo antitumor activity of a novel chlorin derivative for photodynamic therapy.

In presented paper, a new chlorin derivative 5,10,15,20-tetrakis[(5-N-morpholino)pentyl] chlorin (TMC) was investigated as a photosensitizer in photodynamic therapy (PDT). Cellular uptake, cytotoxicity, intracellular location, biodistribution and antitumor effects were studied using human esophageal cancer cells (Eca-109) and human cervical cancer cells (Hela) in vitro and an esophageal cancer model in BALB/c nude mice. Cellular uptake and biodistribution of TMC were measured by fluorescence spectrophotometer. Cytotoxicity of TMC against Eca-109 and Hela cells was determined by MTT assay. The intracellular location of TMC was detected with a confocal microscopy. It was showed that TMC could rapidly accumulate in tumor cells and localize in cytoplasm. TMC was found to be low-toxic in dark but extensively photosensitive in vitro. A fast clearance rate of TMC was observed in Eca-109-bearing mice. In particular, TMC could significantly inhibit the tumor growth and exhibit a notable antitumor efficacy for PDT in vivo.

[Effect of umbilical cord mesenchymal stem cell transplantation on immune function and prognosis of patients with decompensated hepatitis B cirrhosis].

Objective: To investigate the effect of human umbilical cord mesenchymal stem cells (hUCMSCs) on the immune function and prognosis of patients with decompensated hepatitis B cirrhosis. Methods: A total of 65 patients with decompensated hepatitis B cirrhosis were divided into observation group and control group. The patients in the observation group were given intervention (via the proper hepatic artery or the portal vein) and intravenous infusion of 4×108 hUCMSCs in two doses, as well as the same basic treatment as in the control group. The patients in the control group were given conventional medical treatment. ELISA as used to measure the serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), interleukin-10 (IL-10), and transforming growth factor-ß (TGFß) in the observation group before surgery and at 1 week after surgery, as well as the serum levels of IL-6, TNFα, IL-10, and TGFß in the control group on admission and at 1 week after admission. Flow cytometry was used to measure the percentage of lymphocyte subsets in the observation group before surgery and at 1 week after surgery, as well as that in the control group on admission and at 1 week after admission. In addition, the patients' prognosis and major complications during hospitalization were observed in both groups, and the patients were followed up for 24 weeks to record the number of deaths. The t-test was used for comparison of continuous data, and the chi-square test was used for comparison of categorical data which were expressed as percentages. Results: At 1 week after the transplantation of hUCMSCs, compared with the control group, the observation group had significant reductions in the serum levels of IL-6 and TNFα and significant increases in the serum levels of IL-10 and TGFß (all P < 0.001), as well as significant increases in the percentages of T4 cells and Treg cells and significant reductions in the percentages of T8 cells and B cells (all P < 0.05). There were no significant differences in the changes in T3 cells and natural killer cells between the two groups (P > 0.05). Compared with the control group, the observation group had a significantly lower probability of progression to liver failure (6.45% vs 14.71%, P = 0.017). Conclusion: In the treatment of patients with decompensated hepatitis B cirrhosis, transplantation of UCMSCs can inhibit the proliferation of T cells and B cells and the differentiation of T8 cells, upregulate Treg cells, promote the secretion of immunosuppressive cytokines, and reduce the production of inflammatory cytokines. Therefore, it can alleviate liver inflammatory response and liver cell damage and reduce the probability of hepatic failure.

Amphipathic KALA fusogenic peptide enhances absorption of insulin and calcitonin by pulmonary membranes of rats.

OBJECTIVE: The aim was to investigate the absorption-enhancing effect (AEE) of lysine-alanine-leucine-alanine (KALA) repeating unit peptide upon pulmonary absorption of peptide and protein medicines among rats. MATERIALS AND METHODS: Absorption of insulin and calcitonin in the lung was evaluated using varying concentrations of KALA peptide from 0.1% to 1.0% (w/v). The study also examined the lung damage caused by the KALA peptide. RESULTS: KALA peptide with various concentrations improved the absorption of insulin and calcitonin in the lungs. It also reduced glucose and calcium levels in the blood compared to the control, with the AEE increasing in a concentration-dependent manner due to the KALA peptide. In toxicity assays, test results for protein and lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF) did not show a significant increase in the presence of KALA peptide at various concentrations. This implies that the KALA peptide did not cause any membrane damage to lung tissues. In transmembrane electrical resistance (TEER) and permeability detection, a decrease in TEER value and an increase in papp value by the addition of KALA peptide indicated that KALA peptide had the ability to aid the drug delivery through epithelial cells via both paracellular and transcellular pathways. CONCLUSIONS: KALA peptides are suitable as an absorption enhancer at lower concentrations (below 1.0%, w/v) for improving the absorption of insulin and calcitonin from the lung with no observed toxic impact.

Protective effects of protocatechuic acid on growth performance, intestinal barrier and antioxidant capacity in broilers challenged with lipopolysaccharide.

'Prohibition of the antibiotic uses' aggravates the problem of intestinal diseases in poultry, and nutritional regulation has become a research hotspot, such as supplementation with active ingredients derived from plants. This research was conducted to investigate the effects of protocatechuic acid (PCA) on growth, intestinal barrier, and antioxidant capacity of broilers injected with lipopolysaccharide (LPS). Four hundred and eighty 1-day-old yellow feather broilers were randomly allocated to four groups, each with six replicates of 20 broilers. The treatments were basal diet + saline injection (CON) or LPS injection (CON-LPS), and diets with 300 or 600 mg/kg PCA supplementation + LPS injection (P300, P600). Birds were injected intramuscularly on 17th and 19th day of age, then sampled on day 21. The LPS injection significantly decreased BW and average daily gain of broilers, and compared with birds in CON-LPS, PCA supplementation increased (P < 0.05) those variables; moreover, 300 mg/kg PCA also decreased the feed-to-gain ratio. No differences were observed in relative weights of immune organs (P > 0.05). LPS decreased the villus height/crypt depth ratio (V/C) in jejunum of broilers, while PCA (P300 and P600) increased (P < 0.05) the jejunal villus height and V/C compared with birds in CON-LPS. LPS challenge increased jejunal malondialdehyde (MDA) concentration and decreased total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities in plasma (P < 0.05); compared with birds in CON-LPS, jejunal and plasmal GSH-Px activity (P300 and P600) and jejunal T-SOD activity (P300) were decreased (P < 0.05), and hepatic MDA concentration (P600) was increased (P < 0.05). LPS significantly decreased the transcript abundances of OCLN, ZO-1, JAM2, MUC2, SOD1, CAT and GPX in jejunal mucosa of birds, and supplementation with PCA attenuated the decrease in OCLN, JAM2, and MUC2 expression compared with birds in CON-LPS; moreover, 600 mg/kg PCA offset the deduction in SOD1, CAT and GPX expression. In conclusion, dietary supplementation with PCA could improve antioxidant status and attenuate the damage in intestinal barrier and loss in growth performance of LPS-challenged broilers, and 600 mg/kg PCA showed more improved effects on antioxidant capacity.

Tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure.

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Quasimonoenergetic proton bunch generation by dual-peaked electrostatic-field acceleration in foils irradiated by an intense linearly polarized laser.

It is found that stable proton acceleration from a thin foil irradiated by a linearly polarized ultraintense laser can be realized for appropriate foil thickness and laser intensity. A dual-peaked electrostatic field, originating from the oscillating and nonoscillating components of the laser ponderomotive force, is formed around the foil surfaces. This field combines radiation-pressure acceleration and target normal sheath acceleration to produce a single quasimonoenergetic ion bunch. A criterion for this mechanism to be operative is obtained and verified by two-dimensional particle-in-cell simulation. At a laser intensity of ∼5.5×10(22) W/cm(2), quasimonoenergetic GeV proton bunches are obtained with ∼100 MeV energy spread, less than 4° spatial divergence, and ∼50% energy conversion efficiency from the laser.

The contraceptive effect of a novel filtering-type nano-copper complex/polymer composites intra-vas device on male animals.

Contraceptive techniques which target vas deferens have been paid great attention for their good efficacy, safety and reversibility. We have made a filtering-type intra-vas device (IVD) using nano-copper complex/polymer composites. Twenty male adult Beagle dogs and 40 male rabbits were randomly assigned to four groups (sham-operation, IVD, reversal and vasectomy groups). Dogs' semen parameters, concentration of α-glucosidase, copper and zinc ions were tested pre-operation and 1, 3, 6 and 12 months post-operation. The pregnancy rates of the rabbits were evaluated by mating trials after the IVDs were implanted. The histology of testis, epididymides and vas deferens of the animals was examined using an electron microscope. Apoptosis of the cells in the testes, epididymides and vas deferens was detected by TUNEL method. There was no sperm in the semen of dogs, which had been inserted IVD and vasectomized at 1, 3, 6 and 12 months post-operation. The concentration of α-glucosidase in the IVD group, reversal group and sham-operation group was not significantly different between pre- and post-operation. The pregnancy rates of the female rabbits in the vasectomy, IVD and reversal groups were all zero, but the pregnancy rate in the reversal group, after taking out IVD, and that of the sham-operation group was 60% and 80%, respectively. The ultrastructures of the testes, epididymides and vas deferens of the male animals in the IVD group and sham-operation group were in normal ranges compared with the vasectomy group. The apoptosis of the cells in the testes, epididymides and vas deferens in the vasectomy group of both dogs and rabbits was obvious compared with the other groups. No significant changes in the quantities of copper and zinc ions were found in semen of the male dogs both pre- and post-operation. Our studies demonstrated that the filtering-type nano-copper complex/polymer composites intra-vas device may be an efficacious, safe and reversible male contraceptive device.

Plasma devices to guide and collimate a high density of MeV electrons.

The development of ultra-intense lasers has facilitated new studies in laboratory astrophysics and high-density nuclear science, including laser fusion. Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser-matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser-matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.