Physiological mechanisms underlying reduced photosynthesis in wheat leaves grown in the field under conditions of nitrogen and water deficiency

Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants,and leads to a decrease in grain yield.In this study,by measuring the effects of water and N deficiencies,both individually and combined,we characterized the responses of wheat(Triticum aestivum L.Yumai 49-198)plants to these two deficiencies using physiological measurements and comparative proteomics.Significant decreases in grain yield and leaf photosynthetic performance were observed in all deficiency conditions,and 106 photosynthetic proteins that showed responses were identified.Nitrogen deficiency induced the least change in photosynthetic proteins,and similar changes in most of these proteins were also observed for the combined nitrogen and water deficiencies.Water deficiency induced the largest change in photosynthetic proteins and resulted in the lowest 1000-kernel weight.Severe decreases in photosynthesis in both the water-deficiency and combined N and water deficiency groups were reflected mainly in an imbalanced ATP/NADPH ratio associated with the light reaction,which influences carbon metabolism in the Calvin cycle.Photorespiration was respectively stimulated or inhibited by N or water deficiency,while suppression of photorespiratory flux and activation of nitrogen recycling were observed in the combined N and water deficiency treatments.Comparison of photosynthetic proteins between experimental sites suggested that precipitation affected linear electron flow in the photoreaction,and thus photosynthetic efficiency.Our results provide a baseline for future studies of the roles of these photosynthetic proteins in the response to N or water deficiency and their effect on 1000-kernel weight.

States of graphene oxide and surface functional groups amid adsorption of dyes and heavy metal ions

Water pollution regarding dyes and heavy metal ions is crucial facing the world.How to effectively separate these contaminants from water has been a key issue.Graphene oxide(GO)promises the greenwater world as a long-lasting spotlight adsorbent material and therefore,harnessing GO has been the research hotspot for over a decade.The state of GO as well as its surface functional groups plays an important role in adsorption.And the way of preparation and structural modification matters to the performance of GO.In this review,the significance of the state of existence of stock GO and surface functional groups is explored in terms of preparation,structural modification,and adsorption.Besides,various adsorbates for GO adsorption are also involved,the discussion of which is rarely established elsewhere.

高度散光儿童眼前节生物学参数的特征分析

目的:分析高度散光儿童眼前节生物学参数的特征。方法:系列病例研究。收集2020年10月至2021年10月就诊于河南省儿童医院的散光患儿82例(82眼),其中高度散光患儿64例(散光≥2.00 DC),中低度散光患儿18例(散光<2.00 DC)。采用SIRIUS天狼星三维角膜地形图及眼前节分析系统测定患儿眼前节生物学参数,包括角膜参数和前房参数。角膜参数包括角膜最薄点厚度、角膜最薄点位置、中央角膜厚度、角膜体积、角膜前后表面K1、角膜前后表面K2、角膜前后表面球镜度、角膜前后表面柱镜度、光学区4 mm球镜度、光学区4 mm柱镜度;前房参数包括前房深度、水平虹膜直径、虹膜角膜夹角、前房直径。采用独立样本t检验、单因素方差分析等方法对眼前节各生物学参数进行统计学分析。结果:高度散光组儿童与中低度散光组相比,前房参数、角膜厚度和角膜体积差异均无统计学意义,2组角膜最薄点位置分别有97%和89%位于颞下方,高度散光组角膜前、后表面K1值较低(t=-2.61,P=0.011;t=2.40,P=0.019),角膜前、后表面散光及光学区4 mm散光度数较大(t=-11.00,P<0.001;t=5.58,P<0.001;t=-10.25,P<0.001)。散光程度较高组,前房直径较大,2组差异具有统计学意义(F=3.03,P=0.036)。高度散光组屈光状态转化为等效球镜度,等效球镜度越小,前房深度和房角越大,组间差异具有统计学意义(F=11.12,P<0.001;F=5.07,P=0.009)。结论:高度散光组儿童的角膜前后表面散光及光学区4 mm散光较大,角膜最薄点位置大多位于颞下方,角膜前后表面K1值较低,散光程度较高组儿童,前房直径较大,高度散光组等效球镜度越小,前房深度和房角越大。

急性闭角型青光眼慢性期行青光眼白内障联合术后房角功能观察

目的:探讨青光眼白内障联合手术治疗急性闭角型青光眼慢性期合并白内障患者术后房角功能。方法:回顾性系列病例分析。2017年11月至2018年3月在河南省人民医院青光眼中心收治的急性闭角型青光眼慢性期合并白内障患者37例(37眼)。患者为青光眼急性期发作后经药物治疗3~14 d,术前眼压高于21 mmHg(1 mmHg=0.133 kPa);房角关闭范围>2个象限;超声生物显微镜(UBM)示前房变浅,周边虹膜根部与小梁网贴附范围>2个象限;晶状体核混浊度≥Ⅲ级。所有患眼均行常规双切口小梁切除+超声乳化白内障吸除+人工晶状体植入+房角分离术,术中均未使用抗代谢药物,巩膜瓣常规可调节缝线密闭缝合。术前术后观察患者的最佳矫正视力(BCVA)、眼压、中央前房深度、前房角开放程度及滤过泡形成情况。采用Wilcoxon符号秩和检验、方差分析、配对t检验及Pearson相关分析对各项观察指标进行分析。结果:术后7 d时眼压为(18.8±1.7)mmHg,较术前明显下降(t=16.562,P<0.001),15例患者形成滤过泡。术后1个月眼压为(15.5±1.8)mmHg,较术前明显下降(t=20.529,P<0.001),仅有5例患者存在功能性滤过泡。术后半年,眼压为(14.9±2.4)mmHg,23例患者术后眼压<16 mmHg,14例患者术后眼压介于16~20 mmHg之间,较术前眼压明显下降(t=24.458,P<0.001);UBM示所有患者术后房角重新开放范围>2个象限,术后眼压与术前房角粘连程度无相关关系(r=0.016,P=0.926);术后中央前房深度较术前加深(t=-25.195,P<0.001);33例患者术后BCVA较术前提高,4例患者术后BCVA较前无改善,术前术后BCVA差异具有统计学意义(Z=-5.017,P<0.001);5例患者术后上方结膜可见功能性滤过泡形成,32例患者术后未见明显滤过泡,UBM也证实结膜下无有效滤过泡形成。结论:对于急性闭角型青光眼慢性期合并白内障患者,行双切口小梁切除+超声乳化白内障吸除+人工晶状体植入+房角分离术可有效降低眼压。眼压的下降很可能是房角区小梁网功能的恢复,而不是依赖于外滤过通道的建立。