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A new method to remove arsenic from aqueous chloride solution by using lead oxide was proposed, and the effects of the lead(II)/arsenic(V) molar ratio (nPb(II):nAs(V)), initial pH of solution, initial concentrations of chloride ion (Cl−) and arsenic(V) on arsenic removal were investigated. The results showed that nPb(II):nAs(V), initial pH and initial Cl− concentration had great influence on arsenic removal. The suitable conditions of arsenic removal were initial pH of 1.8–2.4 and initial Cl− concentration of 0.52–2.00 g L−1 for 200 mg L−1 As(V) solution. Initial As(V) concentration had little influence on arsenic removal when the appropriate nAs(V):n Cl − was controlled in the solution at nPb(II):nAs(V) of 1.52. Based on these conditions, As(V) removal efficiency reached up to 99.99% and As(V) concentration decreased from 200 mg L−1 to less than 0.01 mg L−1 at initial pH of 1.8 with nPb(II):nAs(V) of 2.12. Various characterizations confirm that the formed precipitate was mimetite (Pb5(AsO4)3Cl) and had better thermal stability within 500 °C. For the prevalent problem of lead dissolution by forming mimetite, Pb residual concentration reduced from 337.6 to 0.07 mg L−1 using sodium sulfide in the solution after arsenic removal. Therefore, lead oxide could be used as an effective reagent of arsenic removal to remove As(V) from aqueous chloride solution.

Primary adenocarcinoma of the vulva is uncommon, and cloacogenic adenocarcinoma of the vulva is extremely rare. Here the authors report a vulvar neoplasm, arising in continuity with the epidermis, characterized by villoglandular architecture, and mucinous-type ep- ithelium with intestinal differentiation (goblet cells). Histochemistry, immunohistochemistry, and gene mutation analysis revealed a colon-like pattern, except for CK7 expression. Extensive workup failed to reveal other primary cancers. In order to provide a much bet- ter experience for diagnosis, the authors compared the previously published cases with the present case regarding clinical presentation and histopathologic aspect. They believe that the notion of the tumor arising from cloacal remnants is a more acceptable viewpoint, and its behavior is mostly indolent. In the present case, a wide local excision was sufficient for radical cure.

To study the distribution characteristics of lactobacillus in the vaginal mucosa of patients with HPV infection.The planting density of lactobacillus in vaginal secretions of 95 cases with HPV16/18 infection and 90 cases of normal women of childbearing age were observed by oil microscope. And the strains of vaginal lactobacilli in two groups were analyzed using species-specific polymerase chain reaction (Species-specific PCR) and the distribution of vaginal lactobacilli in patients with HPV16/18 infection were investigated.In HPV16/18 infective groups, the planting density of lactobacillus in the vaginal mucosa was 104 (68-186)/HP. It was significantly lower than that of the normal group (234 (161-326)/HP, P0.05). Compared with the normal group, the positive rates of lactobacillus iners, lactobacillus crispatus, and lactobacillus gasseri were significantly lower in HPV16/18 infection group (P0.05).The HPV16/18 infection is associated with the decreased number of lactobacillus and the imbalance of vaginal flora; Lactobacillus iners, lactobacillus crispatus, and lactobacillus gasseri may play a key role in maintaining the vaginal micro ecological environment.

This paper reports the characterisation methods used in evaluating the chemical changes in glass fibre/epoxy prepregs during storage in an environment chamber. The specimens were exposed to an environment with a relative humidity of 50% at 25°C for up to 196 days. Various physicochemical analysis methods were used to determine the extent of the changes to the prepregs during storage. These methods include infrared spectroscopy (IR), thermal analysis (TA) and other chemical methods to measure the volatile and insoluble components content. During storage, the chemical reaction occurs between some epoxide groups, which is known as precuring. Results indicate that precuring in the epoxy resin system consumed a considerable number of epoxide groups during the exposure. The epoxide index obtained from IR analysis gives a straight measure of the number of epoxide groups remaining in the prepregs at different stages of the storage. A parameter known as the “precured degree”, defined from the epoxide index, can be used to measure the prepregs’ quality. A set of laminates made from prepregs that had been degraded to different degrees were subjected to flexural and tensile testing. The flexural and tensile properties were significantly reduced as a consequence of the increase in the precured degree for the prepregs. The results show that it is important to control the precuring reaction in epoxy-based prepregs during storage before they are transferred into composite products.

Disturbance may severely degrade the control accuracy of an input-saturated system and even induce instability. This paper intends to present an approach to realize optimal disturbance attenuation for an input-saturated system subject to magnitude-bounded disturbance. Based on circle criterion and the techniques of linear matrix inequalities and convex optimization, stability properties of a system under a known feedback controller are analyzed and an linear approach of synthesizing optimal feedback controller is proposed. Illustrative examples are given and state trajectories of the system before and after stabilization are compared to examine the effectiveness of the proposed approach. The simulation results show that the synthesized controller is effective in stabilizing the system and realizing optimal disturbance attenuation.

Five antibiotics compounds, tetracycline (TC), oxytetracycline (OTC), doxycycline (DOC), chlortetracycline (CTC) and chloramphenicol (CP), were successfully separated and determined by high performance capillary electrophoresis(HPCE). Effects of buffer pH, various organic additives and temperature on electrophoretic separation of antibiotics were investigated. Satisfactory separation of these five antibiotics was achieved in the buffer of pH 3.2, 0.02 mol/L Na2HPO4-0.01 mol/L citric acid with addition of 4% (V/V) N-methylmorpholine and 12% (V/V) acetonitrile within 20 minutes. The calibration graphs were linear by plotting the peak area against the sample concentration over the range of 150 micrograms/L to 750 micrograms/L and the correlation coefficients were greater than 0.9917. The detection limits were 10 micrograms/L for CP, 20 micrograms/L for TC, OTC and DOC and 40 micrograms/L for CP (signal to noise ratio5). HPCE method was successfully applied to the analysis of trace antibiotics in honey.