[Effects of understory removal on soil microbial community composition in subtropical Phyllostachys edulis plantations]. / 林下植物剔除对毛竹林土壤微生物群落结构的影响.

We investigated the effects of understory removal on soil microbial community and soil physicochemical properties in a field experiment following random block design in subtropical moso bamboo (Phyllostachys edulis) plantations, which were widely contributed in middle subtropical area, aiming to assess the regulation mechanism of understory plants on soil microbial community. The results showed that understory removal significantly increased the contents of soil N, NO3--N, and soil available phosphorus, but decreased soil pH and the contents of soil NH4+-N and soil phosphorus (TP). Moreover, understory removal decreased total and bacterial PLFAs (B) and increasing soil fungal PLFAs (F), resulting in a higher F/B ratio. Redundancy analysis showed that changes in fungal PLFAs caused by understory removal were mainly attributed to soil acidification, while changes in bacterial PLFAs caused by understory removal were mainly due to the decreases in soil TP and pH. Furthermore, i14:0、i15:0 and i16:0 contributed to the decreases in bacterial biomass. Our results suggested that understory removal might not be suitable for the management of subtropical P. edulis plantations, as it would alter microbial community composition. The shift of soil microbial community from bacteria to fungi could inhibit microbial decomposition function.

A Benziodoxole-Based Hypervalent Iodine(III) Compound Functioning as a Peptide Coupling Reagent.

1-Benzoyloxy-1,2-benziodoxol-3-(1H)-one (IBA-OBz), a readily available and bench stable benziodoxole-based iodine(III) reagent, can be employed for the synthesis of dipeptides from various standard and sterically hindered amino acids in the presence of (4-MeOC6H4)3P. The combined system of IBA-OBz/(4-MeOC6H4)3P is also successfully applied to the solid-phase peptide synthesis and a pentapeptide leu-enkephalin in unprotected form has been synthesized. Density functional theory calculations reveal that the rate-limiting step is nucleophilic attack of 4-dimethylaminopyridine (DMAP) onto IBA-OBz.

CD4+ TSCMs in the Bone Marrow Assist in Maturation of Antibodies against Influenza in Mice.

The bone marrow (BM) is not only a reservoir of hematopoietic stem cells but a repository of immunological memory cells. Further characterizing BM-resident memory T cells would be helpful to reveal the complicated relationship between the BM and immunological memory. In this study, we identified CD122high stem cell antigen-1 (Sca-1) high B cell lymphoma 2 (Bcl-2) high CD4+ stem cell-like memory T cells (TSCMs) as a distinct memory T cell subset, which preferentially reside in the BM, where they respond vigorously to blood-borne antigens. Interestingly, the natural CD4+ TSCMs homing to the BM colocalized with VCAM-1+ IL-15+ IL-7+ CXCL-12+ stromal cells. Furthermore, compared to spleen-resident CD4+ TSCMs, BM-resident TSCMs induced the production of high-affinity antibodies against influenza by B lymphocytes more efficiently. Taken together, these observations indicate that the BM provides an appropriate microenvironment for the survival of CD4+ TSCMs, which broadens our knowledge regarding the memory maintenance of antigen-specific CD4+ T lymphocytes.

[Resveratrol protects human sperm against cryopreservation-induced injury].

OBJECTIVE: To investigate the effects of resveratrol in the cryopreservation medium on the quality and function of post-thaw sperm. METHODS: Semen samples were obtained from 50 normozoospermic and 50 oligoasthenozoospermic men, liquefied and then cryopreserved in the glycerol-egg yolk-citrate (GEYC) medium with or without 30 µmol/L resveratrol. Sperm motility, viability and acrosome reaction (AR) were examined before and after thawing. Sperm lipid peroxidation and the level of reactive oxygen species (ROS) were measured using commercial malondialdehyde (MDA) and the ROS assay kit. Sperm mitochondrial membrane potential (MMP) and DNA damage were determined by Rhodamine 123 staining and TUNEL. RESULTS: The percentage of progressively motile sperm (PMS), total sperm motility, sperm viability, MMP and AR were significantly decreased (P <0.05) while the levels of sperm ROS, MDA and DNA fragmentation index (DFI) remarkably increased in both the normozoospermia and oligoasthenozoospermia groups after cryopreservation as compared with those in the fresh ejaculate (P <0.05). In comparison with the non-resveratrol control, the post-thaw sperm cryopreserved with 30 µmol/L resveratrol showed markedly higher PMS (ï¼»32.7 ± 4.8ï¼½ vs ï¼»43.1 ± 6.3ï¼½ %, P <0.05), total motility (ï¼»44.8 ± 6.9ï¼½ vs ï¼»56.9 ± 7.4ï¼½ %, P <0.05), viability (ï¼»52.3 ± 6.1ï¼½ vs ï¼»67.5 ± 5.6ï¼½ %, P <0.05), MMP (ï¼»56.5 ± 7.0ï¼½ vs ï¼»63.4 ± 7.5ï¼½ %, P <0.05) and AR (ï¼»16.6 ± 3.8ï¼½ vs ï¼»26.3 ± 4.7ï¼½ %, P <0.05) but lower ROS, MDA and DFI (all P <0.05) in the normozoospermia group, and so did the post-thaw sperm in the oligoasthenozoospermia group, with a particularly lower DFI (ï¼»28.5 ± 4.8ï¼½ vs ï¼»36.3 ± 5.7ï¼½%, P <0.01). CONCLUSIONS: Resveratrol in the cryopreservation medium can improve the quality and function of post-thaw human sperm by reducing cryopreservation-induced sperm injury and the level of ROS.

Lentivirus­mediated RIG­I knockdown relieves cell proliferation inhibition, cell cycle arrest and apoptosis in ATRA­induced NB4 cells via the AKT­FOXO3A signaling pathway in vitro.

Retinoic acid inducible gene I (RIG­I) is upregulated during all­trans retinoic acid (ATRA)­induced terminal granulocytic differentiation of NB4 acute promyelocytic leukemia (APL) cells. However, the function and mechanism of RIG­I in NB4 cells remains to be fully elucidated. In the present study, lentivirus­mediated RIG­I­knockdown was used to investigate the proliferation, cell cycle and apoptotic processes of ATRA­induced NB4 cells in vitro using an MTT assay and flow cytometry, respectively. The roles of RIG­I and the AKT­FOXO3A signaling pathway were investigated using western blot analysis. The results showed that the ATRA­induced expression of RIG­I was specifically and effectively knocked down at the mRNA and protein levels by lentivirus mediated RIG­I short hairpin RNA. In addition, silencing of RIG­I reduced the ATRA­induced inhibition of NB4 cell proliferation, cell cycle arrest and apoptosis. Further investigations indicated that with ATRA­induced expression of RIG­I, levels of phosphorylated (p)AKT­Thr308 and pForkhead Box (FOX) O3A­Thr32 were decreased, the expression levels of cell cycle arrest protein p27 and the apoptotic protein, tumor necrosis factor­related apoptosis­inducing ligand (TRAIL), directly transcribed by FOXO3A were increased. By contrast, following the knockdown of ATRA­induced expression of RIG­I, the levels of pAKT­Thr308 and pFOXO3A­Thr32 were increased, and the protein expression levels of p27 and TRAIL were decreased. Taken together, these results showed that the knockdown of RIG­I reduced the inhibition of cell proliferation, cell cycle arrest and apoptosis in the ATRA­induced NB4 cells via the AKT­FOXO3A signaling pathway.

Coaxial electrospinning of P(LLA-CL)/heparin biodegradable polymer nanofibers: potential vascular graft for substitution of femoral artery.

Electrospinning is one of the most simple and effective methods to prepare polymer fibers with the diameters ranging from nanometer to several micrometers. Poly(L-lactide)-co-poly (ɛ-caprolactone) (P(LLA-CL)) fibers and P(LLA-CL)/heparin coaxial composite fibers herein were successfully prepared by single electrospinning and coaxial electrospinning, respectively. The prepared endothelialized P(LLA-CL) and P(LLA-CL)/heparin vascular grafts were used in the Beagle dogs experiment to evaluate the feasibility of thus made different scaffolds for substitution of dog femoral artery in early period, medium term, and long term, meanwhile the pure P(LLA-CL) vascular graft was used as the control group during all the experiments. The animal model was established by using the graft materials to anastomose both femoral arteries of dogs. The vascular grafts patency rates (i.e., the unobstructed capacity of blood vessel) were detected by color Doppler flow imaging technology and digital subtraction angiography. To observe the histological morphology at different periods, the vascular grafts were removed after 7, 14, and 30 days, and the corresponding histological changes were evaluated by hematoxylin and eosin staining. The experimental results show that in the early period, the patency rates of pure P(LLA-CL) graft, endothelial P(LLA-CL) graft, and P(LLA-CL)/heparin graft were 75%, 75%, and 100%, respectively; in the medium term, the patency rates of pure P(LLA-CL) graft and endothelial P(LLA-CL) graft were 25%, whereas that of P(LLA-CL)/heparin graft was 50%; the patency rates of pure P(LLA-CL) graft and endothelial P(LLA-CL) graft were down to 0%, whereas the patency rate of P(LLA-CL)/heparin graft was 25% in the long term. This preliminary study has demonstrated that P(LLA-CL)/heparin coaxial composite fiber maybe a reliable artificial graft for the replacement of femoral artery. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.