低盐水体Na^(+)/K^(+)对凡纳滨对虾生长、体成分与肝胰腺、鳃组织结构的影响

缺钾在内陆低盐度盐碱水中经常发生,为探究低盐水体中不同钾缺乏程度对凡纳滨对虾生长、存活、体成分以及鳃和肝胰腺组织结构的影响,实验参照海水离子组成配置盐度为2的低盐度水体,在Na^(+)/K^(+)(mg/mg)比值为27、47、67、87、107 (分别记为A、B、C、D、E组)的条件下,对体重为(1.04±0.23) g的凡纳滨对虾幼虾开展了为期60 d的养殖实验。结果显示,E组对虾的存活率为44.64%±20.95%,显著低于A、B、D三组;E组体重为(4.86±0.66) g,显著低于其他4组;A~D组之间的湿重、增重率、特定生长率差异不显著,但均大于E组且差异显著;在饲料系数上,E组最高并与A、D组差异显著。在体成分上,各组全虾钾含量、灰分含量差异不显著,E组的水分含量高于其他组,并与A、B组差异显著;E组粗蛋白含量最低,且与B组差异显著。E组对虾鳃组织角质层明显受损,红细胞数量减少,空泡增多,肝胰腺B细胞及其内部转运泡体积增大,肝小管结构受损。研究表明,低盐条件下严重缺钾引起了对虾鳃和肝胰腺损伤,降低了对虾的存活率和生长率;水体缺钾在前期即可对对虾的生长产生明显影响,而对存活的影响随养殖时间的增加而增大。实验结果有助于为内陆低盐度盐碱水养殖凡纳滨对虾提供理论依据。

Na^(+)/K^(+)-ATPase:ion pump,signal transducer,or cytoprotective protein,and novel biological functions

Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed.

Na^(+)通道在锰神经细胞毒性中的作用

目的初步探讨Na^(+)通道在锰神经细胞毒性中对γ-氨基丁酸(GABA)的作用。方法SH-SY5Y细胞建立锰暴露模型,并分为空白对照组、0.25 mmol/L MnCl_(2)、0.50 mmol/L MnCl_(2)、1.00 mmol/L MnCl_(2)。河豚毒素(tetrodotoxin,TTX)0.10μmol/L、0.20μmol/L进行干预,MTT法测其细胞存活率、光学显微镜进行形态学观察、蛋白质印迹法检测Na^(+)通道中Nav1.1通道蛋白和GABA的标记酶谷氨酸脱羧酶65(GAD65)蛋白的表达水平。结果MnCl_(2)可抑制细胞增殖,0.25 mmol/L MnCl_(2)、0.50 mmol/L MnCl_(2)、1.00 mmol/L MnCl_(2)均可显著降低细胞存活率,差异均具有统计学意义(P<0.05);TTX可改善锰暴露所致的神经元损伤,提高细胞存活率,差异具有统计学意义(P<0.05);锰暴露可上调神经元GAD65蛋白表达水平,差异具有统计学意义(P<0.05),但锰暴露未改变神经元细胞Nav1.1蛋白的表达水平,差异无统计学意义(P>0.05)。结论锰暴露所致神经元损伤及GABA能损伤可能与其Nav1.1蛋白表达无关。

利拉鲁肽通过调控自噬和Na^(+),K^(+)-ATPase活性抑制高糖诱导的心肌细胞肥大

目的探讨利拉鲁肽(liraglutide,LRG)抑制高糖(HG)诱导的心肌细胞肥大的可能机制。方法体外培养H9c2细胞,分为对照(CON)组、HG组、低、中、高剂量LRG(LRG-L、LRG-M、LRG-H)组、LRG-H+自噬抑制剂3-甲基腺嘌呤(3-MA)组。鬼笔环肽染色观察细胞表面积;试剂盒测定细胞膜Na^(+),K^(+)-ATPase(NKA)活性;Real time-PCR和Western blot测定NKAα1、NKAα2 mRNA和蛋白表达;单丹磺胺戊二胺(MDC)荧光染色观察自噬囊泡数量;Western blot测定肥大标志基因(ANP、β-MHC)、自噬标志基因(Beclin-1、LC3、p62)蛋白表达。随后将H9c2细胞分为CON组、HG组、LRG-H组、LRG-H+Sirt1抑制剂EX 527组、LRG-H+AMPK抑制剂Compound C(CC)组,再次检测上述指标;Western blot测定Sirt1/AMPK/mTOR通路相关蛋白表达。结果LRG可抑制心肌细胞肥大,下调ANP、β-MHC蛋白表达;LRG可促进NKA活性恢复,上调NKAα2 mRNA和蛋白表达;LRG可增加自噬囊泡数量,上调Beclin-1、LC3-Ⅱ/LC3-Ⅰ蛋白表达,下调p62蛋白表达;LRG可上调Sirt1、p-AMPK/AMPK蛋白表达,下调p-mTOR/mTOR蛋白表达;使用自噬抑制剂3-MA、Sirt1抑制剂EX 527、AMPK抑制剂CC则部分逆转了LRG的作用。结论LRG可抑制高糖所致心肌细胞肥大,其机制与调控Sirt1/AMPK/mTOR通路激活自噬及促进NKA活性恢复有关。

Effect of monovalent anions on cationic Gemini micro-emulsion

Micro-emulsion usually consists of water, oil, surfactants and co-surfactants, and each component has an effect on the phase behavior and solubilization of the micro-emulsion. When the surfactant in the micro-emulsion system is quaternary ammonium cationic Gemini surfactant, the surfactant mainly combines with the anions in the salt. With the increase of salt concentration, the phase transformation of Winsor I → Winsor III → Winsor II occurred, but the optimum salinity and salt width are different because of the type of salt. The effects of 5 different kinds of monovalent anions, including C_6H_5SO_3^-, I-, Br-, NO_3^- and Cl-, on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are researched by Winsor phase diagram. It is found that the effects of organic anions C_6H_5SO_3-and I-on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are most significant, and the effects of Br-, NO_3^- and Cl-are less significant. Meanwhile, when the optimum solubilization is achieved, the amount of sodium benzoate is the least, indicating that the organic anion has stronger self-organization behavior with quaternary ammonium cationic Gemini surfactants.

Separation of mixed salts(Cl-/SO42-) by ED based on monovalent anion selective membranes

The industrial products or wastewater rich in the mixed salts(Cl-/SO4^2-) not only causes the environmental damage, but also induces waste of resource. In this study, an ED stack with monovalent selective AEMs and conventional CEMs was employed to separate the Cl-and SO42-from simulated wastewater. The effect of current density and mass fraction percentage was investigated in order to optimize the experimental conditions during ED process. It was found that at a concentration ratio between NaCl and Na2SO4 of 95/5(wt%/wt%) and a current density of40 m A·cm^-2, a current efficiency of 72%, an energy consumption of 1.6 k W·h·kg^-1 Na Cl and a Cl-/SO4^2-concentration(67.5/3.5 g·L^-1) were obtained. Hence, it is appropriate and effective to separate Cl-and SO42-by ED using the monovalent selective AEMs.

不同类型盐生植物适应盐胁迫的生理生长机制及Na^(+)逆向转运研究进展

盐生植物是指能在离子浓度至少200 mmol/L以上的生境中生长并完成生活史的植物。盐生植物可分为稀盐盐生植物、泌盐盐生植物、拒盐盐生植物三类。本文从生长形态、生理和分子3个方面总结三类盐生植物响应盐胁迫的不同策略及研究进展,发现盐生植物在分子水平上主要通过Na^(+)转运蛋白和为其提供能量的两类基因应对体内过高Na^(+),这可能是引起盐生植物生理和生长形态异于非盐生植物的重要因素。其中稀盐盐生植物主要通过液泡离子区隔化应对盐胁迫,并表现出肉质化生长形态;泌盐盐生植物通过将体内盐分排出体外应对盐胁迫,并进化出特有的生理结构——盐腺或盐囊泡;拒盐盐生植物通过将盐离子积累在皮层细胞液泡和根部木质部薄壁细胞中减少向上运输Na^(+),同时根部多栓质化减少Na^(+)吸收。本综述旨在为今后研究盐生植物及其耐盐机制提供相关依据,为植物耐盐分子育种奠定基础。

Synthesis, Crystal Structure and Characterization of Energetic Monovalent Copper Azide Complex: [Cu_2(dmpz)(N_3)_2]_n

A novel cuprous azide complex with the formula of [Cu2（dmpz）（N3）2]n（1, dmpz： 2,6-dimethylpyrazine） has been synthesized through hydrothermal synthesis with the reducibility of H3PO3 and structurally characterized by single-crystal X-ray diffraction method. Single-crystal X-ray diffraction analysis reveals the title complex represents a three-dimensional network structure featuring 2D [Cu N3]n plane units bridged by bridging dmpz ligands to form a 3D network. Research results reveal that 1 has lower impact sensitivity and friction sensitivity, which may be expected to become insensitive energetic material and have potential applications. Crystal data： monoclinic, space group C2/c, a = 17.8599（15）, b = 8.2889（5）, c = 14.8076（14） A, β = 113.2580（10）o, V = 2014.0（3） A3, Z = 8, S = 1.025, the final R = 0.0303, w R = 0.0825 for 1460 observed reflections with I 2σ（I） and R = 0.0386, wR = 0.0870 for all reflections. In addition, elemental analysis, IR, and sensitivity characterization are presented.

Monovalent cation perm-selective membranes(MCPMs)"New developments and perspectives

As one of the most typical and promising membrane processes, electrodialysis(ED) technique plays a more and more significant role in industrial separation. Especially, the separation of monovalent cations and multivalent cations is currently a hot topic, which is not only desirable for many industries but also challenging for academic explorations. The main aim of the present contribution is to view the advances of a wide variety of monovalent cation perm-selective membranes(MCPMs) and their preparation technologies including(1) covalent crosslinking,(2) surface modification,(3) polymer blending,(4) electrospinning,(5) nanofiltration alike membrane,and(6) organic–inorganic hybrid. The relevant advantages and disadvantages with respect to some specific cases have been discussed and compared in detail. Furthermore, we elaborately discuss the opportunities and challenges of MCPMs, the fabricating strategies to take and the future perspectives.

温阳益气活血方对慢性心力衰竭大鼠心肌组织Na^(+)-K^(+)-ATP酶、Ca^(2+)-ATP酶的影响

目的观察温阳益气活血方对慢性心力衰竭大鼠心肌组织Na^(+)-K^(+)-ATP酶、Ca^(2+)-ATP酶的影响,探讨其治疗心力衰竭的作用机制。方法采用皮下多点注射异丙肾上腺素制备慢性心力衰竭大鼠模型,将成模大鼠随机分为模型组、西药组和温阳益气活血方低、中、高剂量组,每组14只,另设空白组15只,给药组分别予相应药物灌胃,空白组和模型组予等量生理盐水,连续6周。超声检测大鼠心功能,ELISA检测血清脑钠肽(BNP)含量,计算心脏质量指数(HMI),HE染色观察心肌组织病理变化,酶活比色法、免疫组化及RT-PCR检测心肌组织Na^(+)-K^(+)-ATP酶、Ca^(2+)-ATP酶活性及表达。结果与空白组比较,模型组大鼠左室射血分数(LVEF)、左室短轴缩短率(LVFS)显著降低(P<0.01);血清BNP含量显著增加,HMI显著升高(P<0.01);心肌组织大量纤维水肿,胞质疏松,组织边缘心肌纤维溶解,伴有少量淋巴细胞浸润;心肌组织Na^(+)-K^(+)-ATP酶、Ca^(2+)-ATP酶活性显著减弱,蛋白及mRNA表达显著降低(P<0.01)。与模型组比较,温阳益气活血方高剂量组大鼠LVEF、LVFS显著升高(P<0.01);血清BNP含量显著减少,HMI显著降低(P<0.05,P<0.01);心肌纤维水肿、胞质疏松、炎症浸润、细胞空泡变性及纤维溶解程度均有改善;心肌组织Na^(+)-K^(+)-ATP酶和Ca^(2+)-ATP酶活性显著增强,蛋白及mRNA表达显著升高(P<0.01)。结论温阳益气活血方能通过调节心肌Na^(+)-K^(+)-ATP酶、Ca^(2+)-ATP酶活性及表达改善心力衰竭大鼠心功能不全,发挥治疗慢性心力衰竭的作用。

亚精胺对盐胁迫下黄华占水稻幼苗根系抗氧化酶活性及Na^(+)稳态的影响

以黄华占种子为材料,研究盐胁迫条件下,外源亚精胺(Spd)对水稻幼苗根系的生长、抗氧化酶活性、活性氧(ROS)代谢、丙二醛(MDA)以及Na^(+)稳态的影响。结果表明,经100 mmol/L NaCl溶液处理水稻幼苗根系的ROS、·O_(2)^(-)、H_(2)O_(2)、Na^(+)和MDA含量显著升高,过氧化物酶(POD)和过氧化氢酶(CAT)活性显著降低;在盐胁迫条件下,施用0.1 mmol/L Spd显著提高水稻幼苗根系的CAT和POD活性,显著降低ROS、·O_(2)^(-)、H_(2)O_(2)、Na^(+)和MDA含量,从而减轻Na^(+)毒害和过氧化造成的膜损伤,保护生物膜系统的稳定,维持细胞的稳态。

Influence of monovalent cations and CuO nanoparticles on X-nanozeolite in uranium anionic species separation from contaminated drinking water

The main purpose of this work was the modification of NaX nanozeolite using copper oxide nanoparticles and various monovalent cations such as K^+, Cs^+, and Ag^+in order to make the negatively charged zeolite surface accessible for anionic forms of uranium which are the most dominant species of uranium in the contaminated radioactive waters at natural p H. Various methods such as the X-ray fluorescence(XRF), X-ray powder diffraction(XRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR), and atomic absorption spectroscopy(AAS) were used to characterize the final synthesized absorbents. Batch technique was used to study the adsorption behavior of uranium ions from polluted drinking water by Na X nanozeolite and its modified forms. In order to better understand the performance of them, the results were compared with those that were obtained for synthesizing bulk NaX zeolite and Na-form of clinoptilolite natural zeolite. Preliminary results indicated that uranium sorption increased as the loading level of CuO nanoparticles on NaX nanozeolite increased from 2.1 wt% to 11.2 wt%. In addition,from the obtained data, an increase in uranium removal efficiency resulted as charge/ionic radius ratio of exchanged cation decreased. Also, the effect of contact time, solid–liquid ratio, initial concentration and temperature on the adsorption process was studied. It is worth mentioning that, in this study, the sorption of uranium was performed under natural conditions of pH and the presence of competing cations and anions which are available in drinking waters.

褪黑素通过H_(2)O_(2)调控盐胁迫下小豆Na^(+)/K^(+)平衡机制

为探究褪黑素对盐胁迫下小豆幼苗生长发育的影响,以保红876为材料,设置4个处理:CK(清水)、S(60 mmol/L NaCl)、MT(50μmol/L褪黑素)和S-MT(60 mmol/L NaCl和50μmol/L褪黑素),并分析了小豆幼苗生长指标、光合指标、矿质元素离子含量和抗氧化酶活性的变化。结果表明,在盐胁迫条件下,较CK处理,小豆幼苗的生长受到明显抑制,叶绿素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO_(2)浓度(Ci)显著降低;叶、茎中Na^(+)含量显著上升,叶片中Ca^(2+)含量显著上升而Mg^( 2+)含量则显著下降,豆苗Na^(+)/K^(+)比值显著增加;MDA和H_(2)O_(2)含量显著上升,破坏了膜脂选择透性。盐胁迫下施加褪黑素后,较S处理,显著提高了豆苗株高、叶面积和生物量,总根长显著增加;同时提高了叶绿素含量、叶片Pn、Tr和Ci;叶、茎中Na^(+)和K^(+)含量显著降低,叶片Mg^( 2+)含量显著升高同时Ca^(2+)含量显著降低,豆苗Na^(+)/K^(+)比值降低;MDA、O_(2)^(-)和H_(2)O_(2)含量下降;提高了叶片和根系SOD、POD和CAT活性。正常条件下,施加褪黑素可以促进豆苗的生长,提高幼苗的光合能力,提高了可溶性蛋白含量。对15个代表指标进行Spearman相关分析,发现总根长、叶绿素含量、净光合速率、抗氧化酶活性均与Na^(+)/K^(+)比值和ROS含量呈显著或极显著负相关。综上所述,盐胁迫下,褪黑素通过激活了豆苗抗氧化酶活性,可直接和间接的减少H_(2)O_(2)含量,保持膜脂渗透稳定性,从而利于植物体内Na^(+)/K^(+)平衡;同时,H_(2)O_(2)和Ca^(2+)作为信号分子,在褪黑素调节细胞内离子平衡的过程中存在协同效应,从而提高植物的耐盐能力。

盐胁迫下外源脯氨酸对油菜Na^(+)/K^(+)平衡、生长及抗氧化系统的影响

为探究盐胁迫下外源脯氨酸对油菜生长发育的调控机制,以甘蓝型油菜为试验材料,在150 mmol/L盐胁迫下设置5个外源脯氨酸水平(0、0.25、0.5、1和2 mmol/L),探究外源脯氨酸对盐胁迫下抗氧化系统、渗透物质和离子含量的影响。结果显示:盐胁迫显著抑制油菜的生长,较低浓度(0.25 mmol/L和0.5 mmol/L)外源脯氨酸均可促进油菜的生长,相比0.25 mmol/L外源脯氨酸,施用0.5 mmol/L对油菜长势具有较好的促进作用,能够减少叶片Na^(+)积累,提高K^(+)含量,提高抗氧化酶的活性,并降低活性氧含量。另外,0.5 mmol/L外源脯氨酸还可以促进油菜叶片脯氨酸等渗透物质的积累。而施用较高浓度(1 mmol/L和2 mmol/L)外源脯氨酸不仅没有缓解盐胁迫,还对油菜叶片造成进一步的伤害。综上,盐胁迫会对油菜生长造成损伤,而施用适量外源脯氨酸能够激发抗氧化系统,有效缓解盐胁迫对油菜生长的抑制,提高油菜的耐盐性。

含钾矿物钾释放过程Na^(+)和NH_(4)^(+)的影响

研究阳离子盐溶液振荡平衡浸提条件下三种含钾矿物中钾的释放及动力学模型,为钾矿活化和土壤钾素肥力的评价提供依据。以三种含钾矿物(黑云母、伊利石、蒙脱石)为研究对象,采用阳离子盐溶液(NH_(4)^(+)、Na^(+))进行振荡平衡浸提,分析阳离子对活化钾矿动态释钾过程的影响,研究矿物钾的释放规律及动力学模型。结果表明:(1)不同含钾矿物的非水溶性钾释放存在显著差异,表现为黑云母>伊利石>蒙脱石。(2)不同浸提剂下释钾量表现为NH_(4)Cl>NaCl>H_(2) O,Na^(+)和NH_(4)^(+)较去离子水(对照)相比,分别增加了0.28~1.09倍和0.06~0.70倍。(3)释钾速率随时间的增加表现为先快后慢,最后趋于平缓。快速反应阶段的平均时间为32 h,释钾量占总释钾量的54.86%~80.50%。(4)钾释放动力学模型的决定系数(R 2)为0.805~0.999,黑云母、伊利石的钾释放最优动力学模型均为一级动力学模型,蒙脱石钾释放动力学模型的拟合度效果为一级动力学模型、Elovich模型。Na^(+)能显著提高三种含钾矿物的钾累积吸附量,NH_(4)^(+)对伊利石钾累积吸附量的影响不显著;一级动力学模型是三种含钾矿物释钾的最优动力学模型。本研究可为阳离子活化含钾矿物及土壤钾素肥力的合理评价提供理论依据和数据支撑。

血清Na^(+)水平对慢性心力衰竭患者预后的预测价值

目的 研究血清Na^(+)水平对慢性心力衰竭(Chronic heart failure, CHF)患者预后的预测价值。方法 以2021年1月-12月新疆医科大学第一附属医院心力衰竭科收治的104例CHF伴有低钠血症的患者为低钠血症组,随机抽取研究期间血清Na^(+)水平正常的127例CHF患者为正常血钠组。比较两组患者的临床指标及预后情况,评估血清Na^(+)水平对CHF患者预后的影响。结果 Kaplan-Meier生存分析结果表明伴有低钠血症的CHF患者预后较血清Na^(+)水平正常CHF患者差(Plog rank=0.014),多因素COX回归分析提示血清Na^(+)水平和N端前脑钠肽(NT-proBNP)是CHF全因死亡的独立预测因子(P<0.05),血清Na^(+)水平是CHF患者发生死亡的独立保护因素。受试者工作特征曲线(ROC)显示:血清Na^(+)水平的敏感度为0.564,特异度为0.693,约登指数为0.257,AUC为0.641,(95%CI:0.554-0.728,P=0.002),临界值为134.55 mmol/L。NT-proBNP的敏感度为0.964,特异度为0.318,约登指数为0.282,AUC为0.672,(95%CI:0.593-0.750,P<0.001),临界值为938 pg/mL。两者联合评估CHF预后的AUC为0.700。结论 血清Na^(+)水平对CHF预后具有预测价值,是CHF预后的保护性因素。血清Na^(+)水平和NT-proBNP联合评估可提高对心衰预后的预测价值。

盐度胁迫对彩虹明樱蛤存活、抗氧化酶和Na^(+)/K^(+)-ATP酶活性的影响

为探究彩虹明樱蛤(Moerella iribescens)对盐度胁迫的适应能力和调节机制,对其进行急性盐度胁迫实验,在盐度5~50之间设定10个盐度梯度(5,6,8,11,14,18,23,30,39,50),观察死亡情况。结果显示,盐度胁迫96 h后,盐度50组死亡率为100%,盐度39、30、23、6、5死亡率分别为43.3%、6.7%、3.3%、1.7%、8.3%,而盐度8~18之间的4个组中未发现死亡个体。根据急性胁迫实验结果设置5个盐度梯度(6、12、18、24、30),测定0、24、48、72、96 h鳃和消化腺超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)和Na^(+)/K^(+)-ATP酶活性变化。结果显示,在同一盐度胁迫下,彩虹明樱蛤鳃和消化腺的SOD、CAT、GSH-Px和Na^(+)/K^(+)-ATP酶活性随时间的变化呈先上升后下降并趋于稳定的变化趋势,不同盐度组SOD、CAT和GSH-Px活性在24 h或48 h达到高峰,不同盐度组Na^(+)/K^(+)-ATP活性在48 h或72 h达到高峰。研究表明,彩虹明樱蛤的适宜盐度为8~18,3种抗氧化酶对盐度胁迫响应时间短于Na^(+)/K^(+)-ATP酶。研究从生存适应和应激相关酶活性角度探讨了彩虹明樱蛤对盐度的响应,可为其养殖和保育提供科学依据。

质膜Na^(+)/H^(+)逆向转运蛋白SOS1在植物离子稳态平衡中的作用

植物通过一系列复杂转运系统调节离子稳态以适应盐渍环境,SOS(salt overly sensitive)信号通路是植物响应非生物胁迫的主要信号途径,主要由质膜Na^(+)/H^(+)逆向转运蛋白SOS1、丝氨酸/苏氨酸类蛋白激酶SOS2和钙感应器SOS3组成。SOS1作为SOS信号通路的主要成员之一,广泛存在于高等植物中,由于早期的进化差异,可能导致不同物种SOS1的结构和理化性质存在一定的特异性。SOS1蛋白为一个同型二聚体,每个单体由跨膜和胞内结构域组成,这为整合来自不同途径的信号和调节Na^(+)转运提供了稳定的对接平台。SOS1基因转录水平受到不同胁迫条件的调控,通过Ca^(2+)信号调控、磷酸化、自抑制和与离子转运体协同调控等机制可抑制或激活SOS1活性。该蛋白具有调控植物昼夜节律和pH以及维持离子稳态等功能,在植物逆境胁迫响应中发挥重要作用。论文对SOS1的结构、功能、调控机制及其维持植物离子稳态平衡作用等方面的研究进展加以综述,并对其未来研究方向进行展望,以期为农作物抗逆性遗传改良提供理论支持和优异基因资源。

SELECTION OF NEW EPITOPES FROM MONOVALENT DISPLAYED PHAGE OCTAPEPTIDE LIBRARY

A library of 2 ×107 random octapeptides was constructed by use of phagemid-based monovalent phage display system. The randomly synthesized degenerated oligodeoxyribonucleotides (oligos ) were fused to the truncated g Ⅲ (p230-p403). Sequence analysis of 11 randomly chosen clones suggested that the degenerated inserts and its deduced amino acid (aa) sequences are randomly distributed. The library was used to select binding peptides to the monoclonal antibody (mAb) 9E10, which recognizes a continuous decapeptide epi- tope of denatured human c-myc protein. After four to five rounds of panning, most of the eluted clones could bind to 9E10. Sequence analysis of the selected positive clones indicated that the binding sequences could fall into two classes, one class (clone 1) shares a consensus motif, ISE x x L, with c-myc decapeptide; and the sequences of the other class are entirely different. The binding of both classes to 9E10 could be specifically inhibited by free c-myc decapeptide. The immunogenicity of the phage peptide was further investigated by construction of multivalent displayed phage peptides and immunization of animals with or without adjuvant. ELISA and competitive ELISA showed that anti-serum from both mice and rabbit immunized with either clone could bind to the original antigen, c-myc decapeptide. These results denote that in spite of the dissimilarity of the selected peptides with c-myc decapeptide, they are capable of inducing similar immune respones in vivo, thus actually mimicking the antigen epitope.

血清Na^(+)联合红细胞分布宽度对急性心力衰竭的预后分析

目的 探讨血清钠离子(Na^(+))联合红细胞分布宽度对急性心力衰竭(AHF)患者的预后价值。方法 选取武汉市第七医院在2019年1月至2022年1月期间收治的280例急性心力衰竭患者作为研究对象,患者年龄均>65岁。根据随访期间(90 d)是否发生不良事件将患者分为预后不良组(102例)和非预后不良组(178例)。比较两组患者的一般情况、血清Na^(+)浓度、红细胞宽度等指标水平,并采用ROC曲线分析血清Na^(+)浓度联合红细胞宽度对急性心力衰竭不良预后患者的评估价值。结果 两组患者的年龄、性别、基础疾病情况、吸烟史及LVEDD水平比较,差异无统计学意义(t/χ^(2)=0.415、2.643、2.659、0.185、0.032、0.007、1.648,P>0.05)。预后不良组中心功能分级Ⅳ级、有既往心衰入院史以及血清RDW高于非预后不良组,差异有统计学意义(P<0.05);预后不良组患者的EF、血清Na+浓度低于非预后不良组,差异有统计学意义(t=7.803、11.184,P<0.05)。NYHAⅣ级患者的血清钠水平明显低于NYHAⅢ级患者,而RDW水平高于NYHAⅢ级患者(t=12.102、8.003,P均<0.05);多元回归分析显示血清Na^(+)<138 mmol/L和RDW≥13.14%是AHF预后的独立危险因素(P<0.05)。结论 血清Na^(+)浓度联合红细胞分布宽度可有效评估急性心力衰竭患者病情严重程度,对急性心力衰竭不良预后情况具有较好预测价值及临床意义。