Background Several studies found that vitamin D3 might alter glucose metabolism,protect kidney from injury and even proposed the mechanisms.But results from previous studies have been conflicting.The aim of this study...Background Several studies found that vitamin D3 might alter glucose metabolism,protect kidney from injury and even proposed the mechanisms.But results from previous studies have been conflicting.The aim of this study was to evaluate the efficacy and safety of vitamin D3 in patients with diabetic nephropathy.The underlying mechanism of vitamin D3 decreasing proteinuria is also discussed.Methods We conducted a search of English and Chinese articles using database of Pubmed,Embase,Sinomed,CNKI,Wanfang and clinical trial register centers,for randomized controlled trials of vitamin D3 in diabetic nephropathy patients.Two reviewers performed independently.Meta-analysis was used when studies were homogeneous enough.Results Twenty studies,including 1 497 patients with diabetic nephropathy,were involved in this systemic review.Vitamin D3-treated patients with diabetic nephropathy had a statistically significant reduction in 24-hour proteinuria （weighted mean difference-0.44,95% CI-0.54 to-0.34,Z=8.80,P 〈0.000 01） and urine albumin/creatine ratio （standardized mean difference-0.29,95% CI-0.48 to-0.10,Z=2.96,P=0.003）.But vitamin D3 supplementation did not significantly reduce blood pressure and hemoglobin A1c compared with control group.The potential mechanisms about the renal protection of vitamin D3,including the inhibition of rennin-angiotensin system,the protection of kidney from inflammation,fibrosis and the structure change of kidney are discussed.In addition,vitamin D3 did not significantly increase the incidence of adverse effects,including total adverse effects,gastrointestinal adverse effects and fluctuation of blood pressure.Conclusions Vitamin D3 can ameliorate proteinuria and protect kidney from injury in patients with diabetic nephropathy.This renoprotective effect is independent of blood pressure and glucose reduction.And it does not increase any adverse effects than control,even in combination therapy with angiotensin converting enzyme inhibitors/angiotensin receptor blockers.But due to the limited randomized controlled trials of high quality,more clinical researches should be taken in the future.展开更多
This study considered whether the narrowing of the upper （broad and wandering） reaches of the Lower Yellow River could result in a reduction in sedimentation and even an increase in channel erosion in both the upper...This study considered whether the narrowing of the upper （broad and wandering） reaches of the Lower Yellow River could result in a reduction in sedimentation and even an increase in channel erosion in both the upper and the lower （narrow and meandering） reaches. Analysis of field data and numerical modeling results both justify the proposal to narrow the channel. A positive correlation was found between channel eroded-area and the channel width. Therefore narrowing under conditions of low flow will reduce the amount of erosion in the reach, which, in turn, will reduce the amount of sediment transported into the lower channel. This will reduce the amount of siltation in the lower reaches of the river. However, narrowing under conditions of high flow with a low concentration of sediment will reduce both the extent of flood attenuation along the narrowed channel and the amount of lateral channel bank collapse, which results in increased flows and less sedimentation in the lower channel, leading to increased erosion. When flows with a high concentration of sediment are released from the Xiaolangdi Reservoir, both the lower narrow channel and the upper channel can transport a large amount of the sediment load. It is concluded that the narrowing of the upper broad channel will result in a reduction in sedimentation, or even in channel erosion, in both the upper and the lower channels if the reservoir is operated such that the volume of sediment added during low flows is balanced by the volume eroded during high flows with a low concentration of sediment.展开更多
文摘Background Several studies found that vitamin D3 might alter glucose metabolism,protect kidney from injury and even proposed the mechanisms.But results from previous studies have been conflicting.The aim of this study was to evaluate the efficacy and safety of vitamin D3 in patients with diabetic nephropathy.The underlying mechanism of vitamin D3 decreasing proteinuria is also discussed.Methods We conducted a search of English and Chinese articles using database of Pubmed,Embase,Sinomed,CNKI,Wanfang and clinical trial register centers,for randomized controlled trials of vitamin D3 in diabetic nephropathy patients.Two reviewers performed independently.Meta-analysis was used when studies were homogeneous enough.Results Twenty studies,including 1 497 patients with diabetic nephropathy,were involved in this systemic review.Vitamin D3-treated patients with diabetic nephropathy had a statistically significant reduction in 24-hour proteinuria （weighted mean difference-0.44,95% CI-0.54 to-0.34,Z=8.80,P 〈0.000 01） and urine albumin/creatine ratio （standardized mean difference-0.29,95% CI-0.48 to-0.10,Z=2.96,P=0.003）.But vitamin D3 supplementation did not significantly reduce blood pressure and hemoglobin A1c compared with control group.The potential mechanisms about the renal protection of vitamin D3,including the inhibition of rennin-angiotensin system,the protection of kidney from inflammation,fibrosis and the structure change of kidney are discussed.In addition,vitamin D3 did not significantly increase the incidence of adverse effects,including total adverse effects,gastrointestinal adverse effects and fluctuation of blood pressure.Conclusions Vitamin D3 can ameliorate proteinuria and protect kidney from injury in patients with diabetic nephropathy.This renoprotective effect is independent of blood pressure and glucose reduction.And it does not increase any adverse effects than control,even in combination therapy with angiotensin converting enzyme inhibitors/angiotensin receptor blockers.But due to the limited randomized controlled trials of high quality,more clinical researches should be taken in the future.
文摘This study considered whether the narrowing of the upper （broad and wandering） reaches of the Lower Yellow River could result in a reduction in sedimentation and even an increase in channel erosion in both the upper and the lower （narrow and meandering） reaches. Analysis of field data and numerical modeling results both justify the proposal to narrow the channel. A positive correlation was found between channel eroded-area and the channel width. Therefore narrowing under conditions of low flow will reduce the amount of erosion in the reach, which, in turn, will reduce the amount of sediment transported into the lower channel. This will reduce the amount of siltation in the lower reaches of the river. However, narrowing under conditions of high flow with a low concentration of sediment will reduce both the extent of flood attenuation along the narrowed channel and the amount of lateral channel bank collapse, which results in increased flows and less sedimentation in the lower channel, leading to increased erosion. When flows with a high concentration of sediment are released from the Xiaolangdi Reservoir, both the lower narrow channel and the upper channel can transport a large amount of the sediment load. It is concluded that the narrowing of the upper broad channel will result in a reduction in sedimentation, or even in channel erosion, in both the upper and the lower channels if the reservoir is operated such that the volume of sediment added during low flows is balanced by the volume eroded during high flows with a low concentration of sediment.
