Numerical simulation analysis of heat and mass transfer of saline wastewater in a falling film evaporation tube based on different inlet modes.

Falling film evaporation technology is widely used in the treatment of salt-containing wastewater in coal chemical industry. However, there is still a lack of research on the inlet method of vertical falling film evaporation tubes. In this paper, the heat and mass transfer processes of saline wastewater under vertical and tangential inlets were investigated using numerical simulations. On this basis, the differences in flow and heat transfer processes between saline wastewater and pure water under tangential inlet were investigated. The results showed that the flow velocity of saline wastewater with a falling film evaporation tube in a tangential inlet mode was larger. Meanwhile, the turbulence in this way was more intense and the fluid temperature in the vertical tube was higher. Saline wastewater has higher temperature and smaller liquid volume fraction than pure water liquid membrane in the range of 193-1,000 mm from the inlet. The use of tangential inlet method to treat salt-containing wastewater has higher evaporation efficiency and is a very effective way to guide the improvement of heat transfer efficiency.

Expression and Characterization of a Novel Cold-Adapted Chitosanase from Marine Renibacterium sp. Suitable for Chitooligosaccharides Preparation.

(1) Background: Chitooligosaccharides (COS) have numerous applications due to their excellent properties. Chitosan hydrolysis using chitosanases has been proposed as an advisable method for COS preparation. Although many chitosanases from various sources have been identified, the cold-adapted ones with high stability are still rather rare but required. (2) Methods: A novel chitosanase named CsnY from marine bacterium Renibacterium sp. Y82 was expressed in Escherichia coli, following sequence analysis. Then, the characterizations of recombinant CsnY purified through Ni-NTA affinity chromatography were conducted, including effects of pH and temperature, effects of metal ions and chemicals, and final product analysis. (3) Results: The GH46 family chitosanase CsnY possessed promising thermostability at broad temperature range (0-50 °C), and with optimal activity at 40 °C and pH 6.0, especially showing relatively high activity (over 80% of its maximum activity) at low temperatures (20-30 °C), which demonstrated the cold-adapted property. Common metal ions or chemicals had no obvious effect on CsnY except Mn2+ and Co2+. Finally, CsnY was determined to be an endo-type chitosanase generating chitodisaccharides and -trisaccharides as main products, whose total concentration reached 56.74 mM within 2 h against 2% (w/v) initial chitosan substrate. (4) Conclusions: The results suggest the cold-adapted CsnY with favorable stability has desirable potential for the industrial production of COS.

Adsorption of Cr(VI) from Aqueous Solution by Ethylenediaminetetraacetic Acid-Chitosan-Modified Metal-Organic Framework.

Cu-BTC was synthesised by hydrothermal method in this study to adsorb and remove the toxic heavy metal hexavalent chromium Cr(VI) in water. The EDTA-chitosan/Cu-BTC was prepared by the surface modification of Cu-BTC with EDTA-modified chitosan. The initial concentration effects of adsorbed chromium solution, adsorbent dosage, adsorption time, adsorption temperature and pH of chromium solution on adsorption capacity were estimated using the single-factor optimisation experiment. Results show that the adsorption capacity of the modified composite was higher than that of Cu-BTC. Cu-BTC and EDTA-chitosan/Cu-BTC exhibited significant adsorption of Cr(VI) under acidic conditions in water and basically independent of temperature. Their adsorption processes conformed with the pseudo-second-order model. The Langmuir adsorption isotherm model obtained the adsorption isotherm, which indicated that the adsorption process was single molecule adsorption. Isotherm fitting obtained the maximum adsorption amounts of Cr(VI) for Cu-BTC and EDTA-chitosan/Cu-BTC at 27.32 and 46.51 mg·g-1, respectively. Factor and principal component analyses show that the main factors affecting the adsorption of Cr(VI) in the EDTA-chitosan/Cu-BTC composites are pH, initial concentration and adsorption time. Therefore, EDTA-chitosan-modified Cu-BTC was a more feasible metal-organic framework material than Cu-BTC because of better adsorption performance, which can be used for adsorption removal of Cr(VI) in water.

Expression and clinical significance of peripheral blood CD4~+CD25~+T cells in patients with systemic lupus erythematosis / 中华风湿病学杂志

Objective To investigate the expression and clinical significance of peripheral blood CD4~+, CD25~+ and CD4~+CD25~+ T subpopulations in patients with systemic lupus erythematosis.Methods The per- centage and fluorescence intensities of peripheral blood CD4~+,CD25~+ and CD4~+CD25~+ subpopulations from 34 SLE and 18 normal controls were measured with flow cytometry assay,then the correlation with clincal data was analyzed.The CD25~+ cells were defined as the CD25~(high) cells if their fluorescence intensity was higher than 10. Results The percentage of CD4~+CD25~+,CD4~+CD25~(high) T lymphocytes in active SLE patients[(4.80?1.21)% and (0.25?0.10)%]was lower than that in normal controls[(8.92?3.21)% and(0.44?0.22)% and non-active SLE patients(11.28?2.09)% and(0.59?0.34)%](P＜0.05).However,as for the CD25~+ cells in the CD4~+ T cells,there was no difference between SLE patients and normal control group.Peripheral blood CD4~+CD25~+,CD4~+CD25~(high) cells in SLE were reversely correlated with SLEDAI(r=-0.74,P=0.004 and r=-0.614,P=0.026),but not with others such as complements,ANA titers etc.Peripheral blood CD4~+ and CD25~+ lymphocytes in active SLE pa- tients were also lower than those in normal controls[(23?7)vs(34?7)and(7.4?1.8)vs(13.9?3.4),P＜0.05]. CD25 fluorescence intensities were higher in the SLE patients those in the normal controls,but CD4 fluores- cence intensities were not.Conclusion CD4~+CD25~+ may play a role in the pathogenesis of SLE.

Acquired hemophilia A in patients with systemic lupus erythematosus:report of a case and review of literature / 中华风湿病学杂志

Objective To summarize the manifestation and treatment of acquired hemophilia A in pa- tients with systemic lupus erythematosus(SLE).Method A case was investigated retrospectively and the lit- erature was reviewed.Results A 25-year-old woman with a 5 year history of SLE was admitted to hospital due to abdominal pain.She was diagnosed with acquired factorⅧinhibitor deficiency based on a prolonged activated partial-thromboplastin time(APTT,135.3 s),reduced factorⅧactivity(0.9%)and factorⅧin- hibitor(26.1 BU/ml).Sonography and magnetic nuclear resonance of the abdomen confirmed the presence of a retro-uterine hematoma.The patient was initially treated with intravenous pulse and oral corticosteroids,factorⅧplasma concentrated and intravenous immunoglobulin.Clinical and biological improvement was promptly obtained.Conclusions Attention should be paid to the association between SLE and acquired hemophilia A. Combination therapy may be recommended as initial therapy for the management of acquired hemophilia A in patients with SLE.But no standardized treatment can be recommended at present.