Regulation of Chloroplast ATP Synthase Modulates Photoprotection in the CAM Plant Vanilla planifolia.

Generally, regulation of cyclic electron flow (CEF) and chloroplast ATP synthase play key roles in photoprotection for photosystems I and II (PSI and PSII) in C3 and C4 plants, especially when CO2 assimilation is restricted. However, how CAM plants protect PSI and PSII when CO2 assimilation is restricted is largely known. In the present study, we measured PSI, PSII, and electrochromic shift signals in the CAM plant Vanilla planifolia. The quantum yields of PSI and PSII photochemistry largely decreased in the afternoon compared to in the morning, indicating that CO2 assimilation was strongly restricted in the afternoon. Meanwhile, non-photochemical quenching (NPQ) in PSII and the donor side limitation of PSI (Y(ND)) significantly increased to protect PSI and PSII. Under such conditions, proton gradient (∆pH) across the thylakoid membranes largely increased and CEF was slightly stimulated, indicating that the increased ∆pH was not caused by the regulation of CEF. In contrast, the activity of chloroplast ATP synthase (gH+) largely decreased in the afternoon. At a given proton flux, the decreasing gH+ increased ∆pH and thus contributed to the enhancement of NPQ and Y(ND). Therefore, in the CAM plant V. planifolia, the ∆pH-dependent photoprotective mechanism is mainly regulated by the regulation of gH+ rather than CEF when CO2 assimilation is restricted.

In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep, the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development.</p><p><b>METHODS</b>Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep. A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments. The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed. After 3 months, the lumbar vertebrae with the screws were removed and examined by micro-CT, histological, and biomechanical analyses.</p><p><b>RESULTS</b>Under nonloading conditions, there is bone formation around the surfaces of coated screws. The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most, the one of the collagen/chondroitin sulfate coating and hydroxyapatite coating is followed, and no significant difference between the two groups. In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws, such as bone mineral content, bone mineral density, tissue mineral content, tissue bone mineral density, bone volume fraction, and connection density, those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest. Under nonloading conditions, the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest, and that of the uncoated screws was minimal (P < 0.01). Under loading conditions, the maximum pullout strength of each group of pedicle screws was less than that of the pedicle screws in the nonloading state (P < 0.01) with no significant difference between the groups (P > 0.05).</p><p><b>CONCLUSIONS</b>Under nonloading conditions, the coatings of both organic and inorganic components of the extracellular matrix of titanium pedicle screws can conduct or induce bone formation around the surface of the screws. The ability of collagen/chondroitin sulfate/hydroxyapatite coatings to induce bone formation is stronger; under loading conditions, a large amount of connective tissue formed around the surfaces of the screws in each group. No significant differences were found between the groups.</p>

Artificial neural network parameters optimization software and its application in the design of sustained release tablets / 药学学报

Artificial neural network (ANN) is a multi-objective optimization method that needs mathematic and statistic knowledge which restricts its application in the pharmaceutical research area. An artificial neural network parameters optimization software (ANNPOS) programmed by the Visual Basic language was developed to overcome this shortcoming. In the design of a sustained release formulation, the suitable parameters of ANN were estimated by the ANNPOS. And then the Matlab 5.0 Neural Network Toolbox was used to determine the optimal formulation. It showed that the ANNPOS reduced the complexity and difficulty in the ANN's application.

Short-term and long-term outcomes of moxifloxacin treatment in acute exacerbations of COPD / 中国感染与化疗杂志

Objective To investigate the aetiology of acute exacerbations of COPD (AECOPD),and the effects of moxifloxacin in the treatment of AECOPD.Methods Patients with stable COPD based on GOLD criteria were included in the study.Sputum collected at first exacerbation was analyzed for bacteria count and culture.IL-6,IL-8 and TNF-?were measured by enzyme- linked immunosorbent assay (ELISA).Eligible patients were randomized to receive moxifloxacin (400 mg qd for 5 days) or ce- faclor (250 mg q8h for 7 days).Efficacy parameters were evaluated at 7 and 14 days after treatment initiation and 1 year later. Results Of the 46 patients with moderate or severe COPD (male 38,moderate 24),21 (45.65%) were microbiologically evalu- able at baseline.The main pathogen was Haemophilus influenzae (10/21).Clinical efficacy rate was 87.0% in moxifloxacin group and 82.6% in cefaclor group.Bacterial eradication rate was 80.0% and 72.7% respectively.The difference between groups was not statistically significant in terms of clinical or microbiological efficacy.In moxifloxacin arm,the frequency of ex- acerbation was 2.6?1.0,significantly lower than control arm (3.5?1.4,P

Spatial variability of soil organic carbon in relation to environmental factors of a typical small watershed in the black soil region, northeast China.

A total of 292 soil samples were taken from surface soil (0-20 cm) of a typical small watershed-Tongshuang in the black soil region of Heilongjiang province, northeast China in June 2005 for examining the concentration of soil organic carbon (SOC). Spatial variability of SOC in relation to topography and land use was evaluated using classical statistics, geostatistics and geographic information system (GIS) analyses. The objective of this study was to provide a scientific basis for land management targeting at improving soil quality in this region. Classical statistical analysis results indicated that the variability of SOC was moderate (C (V) = 0.30). Slope position and land use types were discriminating factors for its spatial variability. Geostatistics analyses showed that SOC had a strong spatial autocorrelation, which was mainly induced by structural factors. Mean concentration of SOC in surface soil was 2.27% in this watershed, which was a very low level in the northern black soil region of northeast China. In this small watershed, present soil and water conservation measures played an important role in controlling soil loss. But SOC's restoration was unsatisfactory. Nearly three-quarters of the area had worrisome productivity. How to improve SOC concentration targeting at soil fertility is a pressing need in the future.

Relationship between expression of cyclin D1, Ki-67 and bcl-2 and biologic behavior in CD117-positive gastrointestinal stromal tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathologic features of gastrointestinal stromal tumors (GISTs) and to identify reliable prognostic parameters.</p><p><b>METHODS</b>Fifty-nine GISTs were studied by immunostaining of CD117, CD34, SMA, desmin, S-100, bcl-2, and Ki-67. Histopathologic evaluations included tumor size, necrosis, histological growth patterns, mitotic activities and tumor lymphocytic infiltrate. The patients were clinically followed for 2 to 9 years. Univariate, multivariate and correlative statistical evaluations were used to analyze the data.</p><p><b>RESULTS</b>Among the 59 patients, 40 were alive and 15 died of their tumors at follow-up, the remaining 4 patients died of other causes. Pathological parameters that correlated with prognosis included tumor sizes of more than 5 cm, tumor tissue necrosis, mitotic cell count equal or higher than 5 per 50 high power field, Ki-67 labeling index (LI) equal or higher than 5% and intense bcl-2 immunostaining. Multivariate analysis showed that the mitotic count and Ki-67 LI were independent prognostic indicators. There was a correlation between mitotic count and Ki-67 LI.</p><p><b>CONCLUSIONS</b>Mitotic count and Ki-67 LI are the best predictors for a poor outcome of GIST after surgical treatment. Ki-67 immunostaining may substitute mitotic count as a useful prognostic parameter.</p>