Compatible solutes adaptive alterations in Arthrobacter simplex during exposure to ethanol, and the effect of trehalose on the stress resistance and biotransformation performance.

Ethanol-tolerant Arthrobacter simplex is desirable since ethanol facilitates hydrophobic substrates dissolution on an industrial scale. Herein, alterations in compatible solutes were investigated under ethanol stress. The results showed that the amount of trehalose and glycerol increased while that of glutamate and proline decreased. The trehalose protectant role was verified and its concentration was positively related to the degree of cell tolerance. otsA, otsB and treS, three trehalose biosynthesis genes in A. simplex, also enhanced Escherichia coli stress tolerance, but the increased tolerance was dependent on the type and level of the stress. A. simplex strains accumulating trehalose showed a higher productivity in systems containing more ethanol and substrate because of better viability. The underlying mechanisms of trehalose were involved in better cell integrity, higher membrane stability, stronger reactive oxygen species scavenging capacity and higher energy level. Therefore, trehalose was a general protectant and the upregulation of its biosynthesis by genetic modification enhanced cell stress tolerance, consequently promoted productivity.

Analysis of the SAITS alcoholism model on scale-free networks with demographic and nonlinear infectivity.

A more realistic alcoholism model on scale-free networks with demographic and nonlinear infectivity is introduced in this paper. The basic reproduction number [Formula: see text] is derived from the next-generation method. Global stability of the alcohol-free equilibrium is obtained. The persistence of our model is also derived. Furthermore, the SAITS model with nonlinear infectivity is also investigated. Stability of all the equilibria and persistence are also obtained. Some numerical simulations are also presented to verify and extend our theoretical results.

[Efficacy observation of Thoroughfare Vessel theory in acupuncture for post-stroke dysphasia].

OBJECTIVE: To compare the difference in the efficacy on post-stoke dysphagia between the point selection according to Thoroughfare Vessel theory and conventional point selection in treatment. METHODS: Seventy-eight patients were randomly divided into an observation group (n = 42) and a control group (n = 36). In observation group, acupuncture was applied to the acupoints selected according to Thoroughfare Vessel theory such as Dazhu (BL 11), Shangjuxu (ST 37), Xiajuxu (ST 39), Neiguan (PC 6) and Gongsun (SP 4) Mainly. In control group, acupuncture was applied to the conventional acupoints such as Fengchi (GB 20), Lianquan (CV 23), Tiantu (CV 22), Neiguan (PC 6) and Zusanli (ST 36), etc. Acupuncture was given once per day in either group, 12 treatments made one session and 4 sessions of treatment were required. The water swallow test was adopted to assess the swallowing function in two groups. RESULTS: The effective rate was 100.0% (42/42) in observation group and was 77.8% (28/36) in control group. The efficacy in observation group was superior to control group (P < 0.05). The curative time was (28.65 +/- 10.42) days in observation group and was (38.74 +/- 21.30) days in control group. The time was shorter apparently in observation group as compared with control group (P < 0.05). CONCLUSION: The Thoroughfare Vessel theory in acupuncture treatment for post-stroke dysphasia achieves a superior efficacy as compared with the conventional acupoint selection, and this theory may quickly determine the point prescription in treatment.

[Effects of leaf litter replacement on soil biological and chemical characteristics in main artificial forests in Qinling Mountains].

Through 2 years leaf litter replacement experiments in 4 typical artificial pure forests Larix kaempferi, Pinus tabulaeformis, Catalpa fargesii, and Quercus aliena var. acuteserrata in Qinling Mountains of China, this paper studied the effects of leaf litter replacement on soil biological and chemical characteristics and the interspecific relationships between different tree species. The results showed that the annual decomposition rate of broad-leaved litter was 33.70% higher than that of needle-leaved litter. The annual decomposition rate of needle-leaved litter increased by 8.35%-12.15% when replaced to broad-leaved forests, whereas that of broad-leaved litter decreased by 5.38%-9.49% when replaced to needle-leaved forests. Leaf litter replacement between needle and broad-leaved forests could increase the contents of soil organic-C and available N, P and K, and the increments were obviously higher in needle-leaved forests (8.70%-35.84%) than in broad-leaved forests (3.73%-10.44%). In needle-leaved forests, the increments with the replacement of C. fargesii litter (24.63%-35.84%) were higher than those with the replacement of Q. aliena var. acuteserrata litter (8.70%-28.15%). Furthermore, the replacement of broad-leaved litter could make the soil pH in needle-leaved forests changed from light-acid to neutral, and increase soil enzyme activities, microbial amounts, and microbial biomass C and N contents. The increments with the replacement of C. fargesii litter were higher than those with the replacement of Q. aliena var. acuteserrata litter. The soil enzyme activities, microbial amounts, and microbial biomass C and N contents in broad-leaved forests after the replacement of needle-leaved litter differed with broadleaved tree species. Q. aliena var. acuteserrata forest had the higher soil enzyme activities and microbial biomass C and N contents, while C. fargesii forest was in adverse. It was suggested that in the control of soil degradation under artificial pure forests, much attention should be paid to the direction of interspecific relationship in mixed forestation and leaf litter replacement.