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61.
Background peptide chemistry, and the known 49-amino acid sequence of thymopoietin and the known 9-amino acid sequence of the facteur thymique serique (FTS) allowed the concept that Arg49 of thymopoietin might be linked to Gln1 of FTS in a new 58-amino acid peptide in tissue. Cleavage between Arg49 and Gln50 adjacent to the unique Lys48-Arg49 moiety could liberate thymopoietin and the [H-Gln1]-FTS which could cyclize to FTS by the known reaction. In support of, rather than negating, this concept, synthetic FTS and the new dodecapeptide consisting of Val-Lys-Arg linked to the N-terminal of [H-Gln1]-FTS showed comparable immune stimulating activity, ; both peptides appeared more active than synthetic thymopoietin II. 相似文献
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Haokun Yuan Sarah C. Kramer Eric H. Y. Lau Benjamin J. Cowling Wan Yang 《PLoS computational biology》2021,17(6)
Climate drivers such as humidity and temperature may play a key role in influenza seasonal transmission dynamics. Such a relationship has been well defined for temperate regions. However, to date no models capable of capturing the diverse seasonal pattern in tropical and subtropical climates exist. In addition, multiple influenza viruses could cocirculate and shape epidemic dynamics. Here we construct seven mechanistic epidemic models to test the effect of two major climate drivers (humidity and temperature) and multi-strain co-circulation on influenza transmission in Hong Kong, an influenza epidemic center located in the subtropics. Based on model fit to long-term influenza surveillance data from 1998 to 2018, we found that a simple model incorporating the effect of both humidity and temperature best recreated the influenza epidemic patterns observed in Hong Kong. The model quantifies a bimodal effect of absolute humidity on influenza transmission where both low and very high humidity levels facilitate transmission quadratically; the model also quantifies the monotonic but nonlinear relationship with temperature. In addition, model results suggest that, at the population level, a shorter immunity period can approximate the co-circulation of influenza virus (sub)types. The basic reproductive number R0 estimated by the best-fit model is also consistent with laboratory influenza survival and transmission studies under various combinations of humidity and temperature levels. Overall, our study has developed a simple mechanistic model capable of quantifying the impact of climate drivers on influenza transmission in (sub)tropical regions. This model can be applied to improve influenza forecasting in the (sub)tropics in the future. 相似文献
64.
Lab-scale study of an anaerobic membrane bioreactor (AnMBR) for dilute municipal wastewater treatment 总被引:1,自引:0,他引:1
Seung Hyuk Baek Krishna R. Pagilla Hyung-Jin Kim 《Biotechnology and Bioprocess Engineering》2010,15(4):704-708
Anaerobic bioreactors supplemented with membrane technology have become quite popular, owing to their favorable energy recovery
characteristics. In this study, a lab-scale anaerobic Membrane Bioreactor (AnMBR) was assessed in experimental treatments
of pre-settled dilute municipal wastewater obtained from a full-scaled wastewater treatment plant. The MBR system was operated
in continuous flow mode for 440 days. To evaluate the performance of the AnMBR under various loading rates, the hydraulic
retention time (HRT) was reduced in a stepwise manner (from 2 to 0.5 days). Afterward, the mixed liquor suspended solids (MLSS)
were reduced from 7,000 to 3,000 mg/L in increments of 1,000 mg/L, resulting in a decrease in solids retention time (SRT)
at a constant HRT of 1.0 day. The soluble chemical oxygen demand (SCOD) concentration in the feed varied between 38 and 131
mg/L, whereas the average permeate SCOD ranged between 18 and 37 mg/L, reflecting excellent effluent quality. The AnMBR performance
in terms of COD removal proved stable, despite variations in influent characteristics and HRT and SRT changes. The concentration
of extracellular polymeric substance (EPS) was reduced with decreases in HRT from 42 to 22 mg VS/mg of MLSS, thereby indicating
that the increased biomass concentration biodegraded the EPS at lower HRTs. AnMBR is, therefore, demonstrably a feasible option
for the treatment of dilute wastewater with separate stage nitrogen and phosphorus removal processes. 相似文献
65.
Seung U. Kim 《Histochemistry and cell biology》1976,48(3):205-217
Summary Explants of 10–12 day chick embryo spinal cord were cultured by coverslip-roller tube method for 3–80 days. The cellular and subcellular localization of acetylcholinesterase activity in cultured neurons was studied by the thiocholine techniques of Karnovsky and Roots and Lewis and Shute.At the light microscopic level, acetylcholinesterase was demonstrated in the neurons of both ventral and dorsal horn regions. Occasionally neurons migrated in the outgrowth zone exhibited strong intracellular activity.At the electron microscopic level, acetylcholinesterase activity was found in the nuclear envelope, granular endoplasmic reticulum and the Golgi apparatus of the neurons. No enzyme reaction was detected in the glial cell cytoplasm. 相似文献
66.
Abstract The syntheses of three classes of adenosine analogues involving cyclosubstitution at the 6-position and functionalization at the 2-position are reported. The target molecules synthesized are stable with respect to hydrolytic deamination by mammalian adenosine deaminase, and, because of major structural changes at the 2- and 6-positions, these compounds are expected to be poor phosphorylation substrates for the kinases. Adenosine receptor binding data reveal that several of the compounds synthesized show excellent A1 receptor affinity and A2/A1 selectivity. 相似文献
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Food Biophysics - Caffeic acid phenethyl ester (CAPE) has high cytotoxicity against various cancer cells but has low water solubility and poor bioavailability. The objective of this work was to... 相似文献
70.
The psychrophile Clostridium sp. strain 69 contains a thermolabile triose phosphate isomerase which is inactivated rapidly in vitro and in vivo at 32 C. 相似文献