对二巯基苯促进的孔雀绿的芬顿降解(英文)

研究了对二巯基苯对染料的芬顿降解反应的影响.研究发现,对二巯基苯可以显著加速孔雀绿和罗丹明B等有机染料的芬顿降解,但是不能提高染料的矿化率.通过循环伏安和邻菲啰啉实验,确认对二巯基苯在芬顿反应中的助催化剂作用是通过加速Fe3+/Fe2+的循环实现的.将对二巯基苯和氢醌的助催化效果做了比较.     

水力空化降解壳聚糖产物分子量分布的研究

文章在确定最佳水力空化降解壳聚糖工艺条件的基础上,采用凝胶渗透色谱法测定了壳聚糖不同时间降解产物的分子量分布。结果表明:水力空化降解壳聚糖的效果明显,壳聚糖降解产物的分子量下降显著,降解产物的分散度较原料壳聚糖也有所减小。     

Computation of time domain response by numerical inversion of the Laplace transform

A new method for the calculation of time responses of lumped time invariant networks is presented. It is based on the numerical inversion of the Laplace transform and involves the computation of the frequency domain function at pre-assigned complex points and forming a weighted sum. The method exactly inverts a certain number of terms of the Taylor expansion of the time response and is thus equivalent to the methods used for the integration of differential equations. This equivalence is established on two examples. The order of integration can be changed between 1 and 46 without any difficulty. Additional properties resulting from the application of the numerical Laplace transform inversion are also discussed and some novel applications indicated.     

Cellular immune response to infection by different genotypes of hepatitis C virus

The present study aimed to estimate the cellular immune response to infection by different HCV genotypes in some Egyptian patients with chronic liver disease. HCV-RNA and HCV genotypes were conducted using type-specific primers to amplify the core region of HCV genome. The levels of IFN-gamma and TNF-alpha, PIIINP, SOD enzyme were also determined. The results showed that genotype 4 was the prevalent one (88.57%).Genotype 3 was found mixed with genotype 2 and 4 (11.42% and 34.28% respectively). Genotype 1 was absent from patients under study. No significant differences were observed in the level of IFN-gamma interferon, SOD enzyme and ALT enzyme between those genotypes. On the other hand the level of TNF-alpha was greatly increased in patients infected with mixed HCV genotypes 3, 4 compared with patients with genotype 4 and those infected with mixed genotypes 2, 3. Otherwise PIIINP was decreased significantly of the same group compared with other groups.     

Immunomodulation of ovalbumin-specific IgG and other classes of antibody response by honey in mice

It was reported earlier that intraperitoneal administration of honey had immunosuppressive activity on elicitation of allergen-specific murine antibody response as evaluated by passive cutaneous anaphylaxis and double immunodiffusion methods. In this study, the immunomudulatory effect of honey is evaluated by enzyme linked immunosorbent assay (ELISA) using ovalbumin as model allergen. It was found that ovalbumin (OVA)-specific IgG antibody responses elicited with various doses of OVA were significantly suppressed by rock bee honey (p<0.01). Honey was also found to have inhibited the production of OVA-specific IgM, IgA, IgG₁, and IgG_2b whereas that of IgG_2a and IgG₃ were not affected. Furthermore, honey also suppressed the OVA-specific total IgG antibody response in various inbred mice with different genetic background. In addition, the suppressive activity of honey was examined in different groups of mice by injecting honey at different time intervals, before and after immunization with OVA. The anti-OVA IgG antibody response was suppressed significantly when honey was injected 12 hours prior/latter to OVA injection. These results confirm the suppressive activity of honey on antibody response and suggest possible clinical application.     

Identifying humanitarian information for emergency response by modeling the correlation and independence between text and images

Information residing in multiple modalities (e.g., text, image) of social media posts can jointly provide more comprehensive and clearer insights into an ongoing emergency. To identify information valuable for humanitarian aid from noisy multimodal data, we first clarify the categories of humanitarian information, and define a multi-label multimodal humanitarian information identification task, which can adapt to the label inconsistency issue caused by modality independence while maintaining the correlation between modalities. We proposed a Multimodal Humanitarian Information Identification Model that simultaneously captures the Correlation and Independence between modalities (CIMHIM). A tailor-made dataset containing 4,383 annotated text-image pairs was built to evaluate the effectiveness of our model. The experimental results show that CIMHIM outperforms both unimodal and multimodal baseline methods by at least 0.019 in macro-F1 and 0.022 in accuracy. The combination of OCR text, object-level features, and the decision rule based on label correlations enhances the overall performance of CIMHIM. Additional experiments on a similar dataset (CrisisMMD) also demonstrate the robustness of CIMHIM. The task, model, and dataset proposed in this study contribute to the practice of leveraging multimodal social media resources to support effective emergency response.     

High-yield production of the human lysozyme by Pichia pastoris SMD1168 using response surface methodology and high-cell-density fermentation

BackgroundLysozyme plays a crucial role in innate immunity with its well-recognized bacteriolytic activity. In this study, the influence of expression parameters (inoculation volume, culture volume, growth time, induction temperature and time, initial pH and methanol concentration) on human lysozyme (HLZ) production in recombinant P. pastoris SMD1168 was investigated through Plackett–Burman (PB) design and response surface methodology (RSM).ResultsIt was revealed that induction temperature, induction time and culture volume had significant influence (P < 0.01) on HLZ expression level, which were elected for further optimization with three-dimensional response surface designs for enhanced HLZ production. The highest lysozyme activity reached 3301 U/mL under optimized conditions (at 23.5°C for 90 h with culture volume of 48 mL) in shake flask, which increased 2.2 fold compared with that achieved with the standard protocol (Invitrogen). When high-cell-density fermentation of the recombinant Pichia pastoris was performed in a 15 L fermenter under optimized conditions, the extracellular lysozyme activity reached 47,680 U/mL. SDS-PAGE analysis of the product demonstrated that HLZ was produced as a single major protein with a molecular weight of approximately 14.7 kDa, consistent with its expected size.ConclusionsThe results indicated that the optimized culture conditions using PB design and RSM significantly enhanced the expression level of HLZ, and the Pichia expression system for HLZ production was successful and industrially promising.     

Arsenic tolerance and bioleaching from realgar based on response surface methodology by Acidithiobacillus ferrooxidans isolated from Wudalianchi volcanic lake,northeast China

BackgroundTraditional methods of obtaining arsenic have disadvantages such as high cost and high energy consumption. Realgar is one of the most abundant arsenic sulphide minerals and usually treated as waste in industry. The aim of the present study was to screen an arsenic tolerant bacterium used for bioleaching arsenic from realgar.ResultsAn acidophilic iron-oxidizing bacterium BYQ-12 was isolated from Wudalianchi volcanic lake in northeast China. BYQ-12 was a motile, rod-shaped gram-negative bacterium with an optimum growth at 30°C and pH 2.5. 16S rDNA phylogeny showed that BYQ-12 was a new strain of Acidithiobacillus ferrooxidans. The inhibitory concentrations (ICs) of arsenite and arsenate were 32 and 64 mM, respectively. A significant second-order model was established using a Box–Behnken design of response surface methodology (BBD-RSM) and it estimated that a maximum arsenic bioleaching rate (73.97%) could be obtained when the pulp concentration, pH and initial ferrous ion concentration were set at optimized values of 0.95% w/v, 1.74 and 3.68 g/L, respectively. SEM, EDS and XRD analyses also revealed that there was direct bioleaching besides indirect electrochemical leaching in the arsenic bioleaching system.ConclusionFrom this work we were successful in isolating an acidophilic, arsenic tolerant ferrous iron-oxidizing bacterium. The BBD-RSM analysis showed that maximum arsenic bioleaching rate obtained under optimum conditions, and the most effective factor for arsenic leaching was initial ferrous ion concentration. These revealed that BYQ-12 could be used for bioleaching of arsenic from arsenical minerals.