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AIM: To compare the clinical outcomes of wavefront guided femtosecond LASIK (WFG LASIK) and conventional femtosecond LASIK (NWFG LASIK) in eyes with myopia and myopia astigmatism. METHODS: This was a retrospective, nonrandomized, comparative investigation enrolling 236 eyes of 122 patients (18-50y) with low & moderate and high myopia. The WFG group including 97 eyes (50 patients) undergone WFG LASIK and the NWFG group including 139 eyes (72 patients) undergone conventional LASIK. Mean efficacy index, high order aberrations (HOAs), pupil size and the quality of visual questionnaire were evaluated 6mo postoperatively. RESULTS: There is no difference between WFG group (-0.054±0.049 in logMAR) and NWFG group (-0.040±0.056) in uncorrected distance visual acuity (UDVA) postoperatively. The myopia astigmatism is higher in WFG group than that in NWFG group (P

Angiogenesis is a complex process, which involves the sprouting of new blood vessels from pre-existing vasculature. Pathological retinal angiogenesis can lead to vision loss and even blindness. Cyclin-dependent kinase 1 (CDK1) is involved in regulation of the cell cycle and is reported to contribute to tumor progression. However, the role of CDK1 in retinal angiogenesis is largely unknown. The purpose of the present study was to investigate the role of CDK1 in retinal angiogenesis. Western blotting, reverse transcription-quantitative PCR (RT-qPCR) analysis, immunofluorescence and immunohistochemistry were used to evaluate the expression of CDK1 in pathological angiogenesis using an oxygen-induced retinopathy (OIR) mouse model. Small interfering (si)RNA sequences against CDK1 were synthesized and incubated with retinal cells. The efficiency of knockdown was confirmed by western blot and RT-qPCR assays. The effect of CDK1 siRNAs on angiogenesis in vitro was investigated using EdU cell proliferation, cell migration and tube formation assays. Subsequently, flow cytometry was used to assess the effects of CDK1 siRNAs on cell cycle distribution and on the induction of apoptosis. The expression levels of cell cycle- and apoptosis-related genes were detected using western blotting. CDK1 was overexpressed in pathological retinal angiogenesis. CDK1 siRNAs inhibited human umbilical vein endothelial cell proliferation, migration and tube formation. The possible mechanisms involved the induction of cell cycle arrest at the G2/M phase and the induction of apoptosis via an increase in the expression levels of p21 and p53. In conclusion, the data indicated that CDK1 was overexpressed in the OIR model and that silencing of CDK1 inhibited angiogenesis in vitro. CDK1 may be a novel therapeutic target for pathological retinal angiogenesis.

A field growing/non-growing season asymmetric warming experiment (C: control, i.e., no warming in the entire year; GLNG: growing season warming lower than non-growing season warming; GHNG: growing season warming higher than non-growing season warming) was conducted in an alpine meadow of the Northern Tibetan Plateau in early June 2015. The effects of growing/non-growing season asymmetric warming on the normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), aboveground biomass (AGB) and gross primary production (GPP) in 2015–2017 were examined. The ‘GLNG’ and ‘GHNG’ treatments significantly increased the annual mean air temperature (Ta) by 2.95 °C and 2.76 °C, and the vapor pressure deficit (VPD) by 0.23 kPa and 0.28 kPa but significantly reduced the annual mean soil moisture (SM) by 0.02 m3 m−3 and 0.02 m3 m−3 respectively; however, changes in the annual mean Ta, VPD and SM were the same between the ‘GLNG’ and ‘GHNG’ treatments over the three years in 2015–2017. There were no significant differences in the SAVI and GPP among the ‘C', ‘GLNG’ and ‘GHNG’ treatments over the three growing seasons in 2015–2017. The ‘GLNG’ and ‘GHNG’ treatments did not significantly affect the NDVI and AGB compared to ‘C’, whereas the NDVI and AGB under the ‘GLNG’ treatment were significantly greater than those under the ‘GHNG’ treatment over the three growing seasons in 2015–2017. The significant differences in NDVI and AGB between the ‘GLNG’ and ‘GHNG’ treatments may be attributed to the different effects under the ‘GLNG’ and ‘GHNG’ treatments on the non-growing season Ta, growing season water availability and soil nitrogen availability. Therefore, the non-growing season with a higher warming magnitude may have stronger effects on the aboveground plant production than did the growing season with a higher warming magnitude in the alpine meadow of the Northern Tibetan Plateau.

Precipitation and growing season length (GSL) are vital abiotic and biotic variables in controlling vegetation productivity in alpine regions. However, their relative effects on vegetation productivity have not been fully understood. In this study, we examined the responses of the maximum normalized difference vegetation index (NDVImax) to growing season precipitation (GSP) and GSL from 2000 to 2013 in 36 alpine grassland sites on the Tibetan Plateau. Our results indicated that NDVImax showed a positive relationship with prolonged GSL (R2 = 0.12) and GSP (R2 = 0.39). The linear slope of NDVImax increased with that of GSP rather than GSL. Therefore, GSP had a stronger effect on NDVImax than did GSL in alpine grasslands on the Tibetan Plateau.

AIM: To investigate the effect of gold nanoparticles on retinal angiogenesis in vitro and in vivo, and to reveal the possible mechanism. METHODS: Seed growth method was used to synthesize gold nanoparticles (GNPs). The size, zeta potential, absorption spectrum and morphology of GNPs were identified using Malvern Nano-ZS, multimode reader (BioTek synergy2) and transmission electron microscope. Cell viability was analyzed using cell counting kit-8 method and cell growth was assessed with EdU kit. Transwell chamber was used to investigate cell migration. Tube formation method was used to assess the angiogenic property in vitro. Oxygen induced retinopathy (OIR) model was used to investigate the effect of GNPs on retinal angiogenesis. Confocal microscope and Western blot were used to study the possible mechanism of GNPs inhibited angiogenesis. RESULTS: The GNPs synthesized were uniform and well dispersed. GNPs of 10 μg/mL and 20 μg/mL were able to inhibit human umbilical vein endothelial cells proliferation (50% and 72% separately, P

The general impact of extra nitrogen on ecological stoichiometry was examined in alpine grasslands on the Tibetan Plateau. Extra nitrogen increased the ratio of nitrogen to phosphorus (N:P ratio) in leaves and aboveground parts of plants by 43.4% and 32.7%, respectively. In contrast, extra nitrogen reduced the ratio of carbon to nitrogen (C:N ratio) in leaves by 30.6%. Extra nitrogen decreased soil C:N ratio by 9.1% in alpine meadows, but increased soil C:N ratio by 3.4% in alpine steppes. Extra urea had a stronger positive impact on aboveground vegetation N:P ratio than did extra ammonium nitrate. Extra urea rather than ammonium nitrate decreased aboveground vegetation C:N ratio and soil C:N ratio. The impact of extra nitrogen on aboveground vegetation N:P ratio was positively correlated with latitude, mean annual temperature and precipitation, nitrogen application rate and accumulated amount, but negatively correlated with elevation, duration and aboveground vegetation N:P ratio of the control plots. The impact of extra nitrogen on leaves N:P ratio was positively correlated with nitrogen application rate and accumulated amount. The impact of extra nitrogen on leaves C:N ratio was positively correlated with latitude, but negatively correlated with mean annual temperature and precipitation, nitrogen application rate, accumulated amount, duration and leaves C:N ratio of the control plots. Therefore, nitrogen enrichment caused by human activities will most likely alter element balance and alpine plants from nitrogen limitation to phosphorus limitation. This effect may weaken with time, and increase with climatic warming, increased precipitation and nitrogen input rate.