Identifying Intraspecific Variation in Venom Yield of Chinese Cobra (Naja atra) from Ten Populations in Mainland China

Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra (Naja atra) is a large sized, venomous snake commonly found in southeastern China, where it causes a heavy burden of snakebites. To examine the effects of various factors (morphology, sex, age, season, and geographical origin) on the venom yield in this snake, we collected venom samples of 446 individuals (426 adults and 20 neonates) from 10 populations of N. atra over an eight-year period. We used two variables, lyophilized venom mass (venom yield) and solid content of venom (% solids), to quantify the venom yield. We used linear regression analysis to check if venom yield was related to morphological factors, one-way ANOVA and one-way ANCOVA to detect the sexual, ontogenetic, and geographic variation in venom yield, and repeated-measures ANOVA to examine seasonal shifts in venom yield. Our results indicate that venom yield of N. atra is positively related to the morphological traits examined, with male snakes expelling more venom than females. Venom yield in N. atra was age-related, with elder snakes always expelling more venom than younger ones. Geographic variation in venom yield was also observed, while seasonal variation was not. The solid content of venom was lower in males than in females, but this was not related to morphology, season, age, or geography. Our findings suggest that venom yield in N. atra is influenced by multiple factors, as well as by the interactions among these factors

Development of material removal function in atmospheric pressure plasma jet machining processing

The removal function is one of the key factors in achieving ultra-precision machining results by computer controlled optic surface principle. In the atmospheric pressure plasma jet machining process,the distribution of active radicals on the workpiece surface is one of the major factors that affect the removal function. However, the distribution of jet pressure on the workpiece surface affects the distribution of active radicals. The pressure distribution of the plasma jet effluent on the workpiece surface has been simulated according to jet theory. The spatial density distribution of active radicals is measured with atomic emission spectroscopy. The results show that there is a relationship between the activeradical distribution and the jet pressure distribution. Finally, based onexperimental data, the material removal function model has been developed by curve fitting, and in this model, the reactive gas flux and the distance between the nozzle and the workpiece is defined/calculated/obtained by the parametersof the removal function

Quantitative analysis of the risk of hydrogen sulfide release from gas hydrates

The role that H2S plays in the global sulfur cycle has been studied extensively in recent years. This paper focuses on the influence of H2S released from gas hydrates on sulfur cycle and establishes a one-dimensional mathematical model to calculate the amount of H2S released from the dissociation of gas hydrates present in multiple layers in the Qiongdongnan Basin China. The results show that the sulfate and methane transition zone that covers an area of about 100 km2in the Qiongdongnan Basin contains 2.3 × 1012 g of pyrite, which requires 4.06 × 1011 mol of H2S for its formation. The H2S released from the dissociation of gas hydrates is 5.4 ×1011 mol, which is about 1.3 times that needed for the formation of pyrite. Therefore, the H2S released from the gas hydrates is an important source of H2S for the formation of pyrite in the sulfate-methane transition zone of Qiongdongnan Basin. According to the flux of H2S and the partial pressure of O2 (PO2) in the atmosphere, the critical value of the balance between the flux of H2S and PO2 turns out to be 0.13 mol kg−1∙bar−1. Furthermore, considering the effect of global sea-level changes, three risk modes are identified to categorize the amount of H2S released from the dissociation of gas hydrate into the atmosphere. We classify the periods from 5–12 Ma BP, 25–29 Ma BP, 47–52 Ma, and 57–61 Ma BP into the high-risk mode. Furthermore, the results show that a part of the H2S released from the gas hydrate dissociation is oxidized by the Fe (III) oxide metal, with much of the metal ions being released into the pore water. Another part of the H2S is re-oxidized by the O2 in the ocean, with much of SO42- released into the seawater. Therefore, the process also provides metal ions and SO42- to pore water or seawater when the H2S released from gas hydrate diffuses from the bottom. This paper provides new insights into the source of H2S in the ocean and shows that the H2S contained in gas hydrates plays an important role in the global sulfur cycle

Effect of Liposomal Transfection of UCH-L1 siRNA on Proliferation and Apoptosis of Lung Cancer Cell Line H157

Background and objective Several reports demonstrated that the ubiquitin C terminal hydrolase-L1 (UCH-L1) has been found to be an oncogene in malignant tumors such as esophageal carcinoma, lung cancer and breast cancer. The aim of this study is to explore the effects of liposomal transfection of UCH-L1 siRNA on the proliferation and apoptosis of lung adenocarcinoma cell lines H157. Methods UCH-L1 siRNA was synthesized and transfected into H157 cell by liposome. Cell morphological change was observed with microscope, and cell proliferation and apoptosis index detected by flow cytometry, UCH-L1 mRNA expression was determined by RT-PCR and protein level of UCH-L1 was determined by Western blot. Results For the H157 cell transfected with siRNA, cell proliferation was inhibited significantly, cell apoptosis appeared obviously, the expression of UCH-L1 mRNA and protein level of UCH-L1 significantly decreased. Conclusion UCH-L1 siRNA is able to inhibit the proliferation of lung adenocarcinoma cell lines H157 and induce the apoptosis. UCH-L1 might become a new target for lung carcinoma gene therapy

Pilot-Scale Selective Electrodialysis for the Separation of Chloride and Sulphate from High-Salinity Wastewater

The separation of chloride and sulphate is important for the treatment of high salt wastewater, and monovalent selective electrodialysis (MSED) has advantages in terms of energy consumption and pre-treatment costs compared to nanofiltration salt separation. Most of the research on monovalent anion-selective membranes (MASM) is still on a laboratory scale due to the preparation process, cost, and other reasons. In this study, a low-cost, easy-to-operate modification scheme was used to prepare MASM, which was applied to assemble a pilot-scale electrodialysis device to treat reverse osmosis concentrated water with a salt content of 4% to 5%. The results indicate that the optimum operating conditions for the device are: 250 L/h influent flow rate for the concentration and dilute compartments, 350 L/h influent flow rate for the electrode compartment and a constant voltage of 20 V. The separation effect of the pilot electrodialysis plant at optimal operating conditions was: the Cl− and SO42− transmission rates of 80% and 2.54% respectively, the separation efficiency (S) of 93.85% and the Energy consumption per unit of NaCl (ENaCl) of 0.344 kWh/kg. The analysis of the variation of the three parameters of selective separation performance during electrodialysis indicates that the separation efficiency (S) is a suitable parameter for measuring the selective separation performance of the device compared to the monovalent selectivity coefficient (PSO42−Cl−)

Analysis of Fiberglass Winding Angle on Natural Frequency of Free Vibration of Cylindrical Shell with Asymmetric Boundary Conditions

In order to obtain approximate solution of natural frequencies for the free vibration of anisotropic circular cylindrical shells made of GFRP (glass fiber-reinforced plastic) with asymmetric boundary conditions, Love’s theory and energy method are used. Computation results show that the fundamental natural frequency comes from different vibration modes while the winding angle varies, the effect of number of axial half waves is stronger than number of circumferential waves on natural frequency of free vibration of anisotropic circular cylindrical shell. The effect of shell’s geometrical parameters is also investigated on natural frequencies

Analysis of Fiberglass Winding Angle on Natural Frequency of Free Vibration of Cylindrical Shell with Asymmetric Boundary Conditions

In order to obtain approximate solution of natural frequencies for the free vibration of anisotropic circular cylindrical shells made of GFRP (glass fiber-reinforced plastic) with asymmetric boundary conditions, Love’s theory and energy method are used. Computation results show that the fundamental natural frequency comes from different vibration modes while the winding angle varies, the effect of number of axial half waves is stronger than number of circumferential waves on natural frequency of free vibration of anisotropic circular cylindrical shell. The effect of shell’s geometrical parameters is also investigated on natural frequencies