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1.
Liu Y  Tang F  Kang CJ  Cao X 《Luminescence》2012,27(4):274-278
Detection of hydrogen sulphide (H2S) was conducted based on cataluminescence (CTL) sensors, using alkaline‐earth metal carbonates as catalysts. Optimal working conditions, analytical characteristics and the response properties of the sensor were investigated. CTL intensity examination showed that sensors fabricated with CaCO3, SrCO3 or BaCO3 could be used to detect H2S gas sensitively. The optimal sensing temperature was about 320 °C. Under the sensing conditions with temperature at ca. 320 °C and gas flow rate in the range 180–200 mL/min, the linear range of CTL intensity vs H2S concentration was 25–500 ppm, with a detection limit of 2 ppm. The response and recovery times of the sensor were within 5 and 25 min, respectively. Also, the sensor had the property of high selectivity to H2S with very weak or no obvious response to 14 other gases, such as NO2, NH3, hydrocarbons and alcohol. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

2.
In the present work, Fe3O4–carbon nanotubes (CNTs) composite was explored as a sensing material candidate for ammonium sulfide. Intense chemiluminescence emission can be observed during the catalytic oxidation of ammonium sulfide on the surface of Fe3O4–CNTs composite. Based on this phenomenon, a selective and sensitive gas sensor for the determination of ammonium sulfide was demonstrated. Under the optimized conditions, the linear range of cataluminescence intensity vs concentration of ammonium sulfide gas was 1.4–115 µg mL?1 (R = 0.998) with a limit of detection (S/N = 3) of 0.05 µg mL?1. The relative standard deviation (n = 5) for 14.3 µg mL?1 ammonium sulfide was 1.9%. There was no response to common foreign substances, such as sulfur dioxide, toluene, aether, ethanol, acetone, hydrogen sulfide, carbon bisulfide, benzene and ammonia. The proposed sensor was successfully applied for the determination of ammonium sulfide in artificial air samples. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

3.
The reactions of acetaldehyde with O atoms in the cages of large-pore zeolites have been discovered to result in light emission. The luminescence characteristics of acetaldehyde vapours passing through the surface of chosen zeolites were studied using a cataluminescence-based detection system. To demonstrate the feasibility of the method, the detection of acetaldehyde using catalysts was studied systematically and a linear response of 0.06-31.2 microg/mL acetaldehyde vapour was obtained. Methanol, ethanol, isopropanol, methylbenzene, chloroform, dichlormethane and acetonitrile did not interfere with the determination of acetaldehyde. Acetaldehyde vapour could also be distinguished from some homologous series such as formaldehyde, cinnamaldehyde, glutaraldehyde and benzaldehyde on this catalyst, possibly due to the stereoselectivity of the zeolite and its specific reaction mechanism. Moreover, acetaldehyde was quantified without detectable interference from formaldehyde in four artificial samples. Thus, this kind of cataluminescence-based sensor could be potentially extended to the analysis of volatile organic compounds in air, and the simple and portable properties of cataluminescence-based sensors could also make them beneficial in many areas of analytical science.  相似文献   

4.
A simple and sensitive gas sensor was proposed for the determination of 1,2‐propylene oxide (PO) based on its cataluminescence (CTL) by oxidation in the air on the surface of CeO2 nanoparticles. The luminescence characteristics and optimal conditions were investigated in detail. Under optimized conditions, the linear range of the CTL intensity versus the concentration of PO was 10–150 ppm, with a correlation coefficient (r) of 0.9974 and a limit of detection (S/N = 3) of 0.9 ppm. The relative standard deviation for 40 ppm PO was 1.2% (n = 7). There was no or only weak response to common foreign substances including acetone, formaldehyde, ethyl acetate, acetic acid, chloroform, propanol, carbon tetrachloride, ether and methanol. There was no significant change in the catalytic activity of the sensor for 100 h. The proposed method was simple and sensitive, with a potential of detecting PO in the environment and industry. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

5.
A cataluminescence (CTL) sensor using Y2O3 nanoparticles as the sensing materials was proposed for the determination of ethyl acetate. This ethyl acetate sensor showed high sensitivity and specificity at the optimal temperature of 264°C. Quantitative analysis was performed at a wavelength of 425 nm. The linear ranges of CTL intensity vs ethyl acetate concentrations were 2.0–250 ppm (r = 0.9965) and 250–6500 ppm (r = 0.9997) with a detection limit (3σ) of 0.5 ppm. There was no response or weak response when foreign substances such as formic acid, n‐hexane, toluene, acetic acid, benzene, and formaldehyde passing through the surface of Y2O3 nanoparticles. The sensor had a long lifetime more than 80 h with 3600 ppm ethyl acetate. It had been applied successfully to determine ethyl acetate in artificial air samples. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

6.
Gu. Gong  Hua Zhu 《Luminescence》2016,31(1):183-189
A gaseous sensor system was developed for the detection of methane based on its cataluminescence emission. Cataluminescence characteristics and optimal conditions were studied in detail under optimized experimental conditions. Results showed that the methane cataluminescence sensor system could cover a linear detection range from 10 to 5800 ppm (R = 0.9963, n = 7) and the detection limit was about 7 ppm (S/N = 3), which was below the standard permitted concentration. Moreover, a linear discriminant analysis method was used to test the recognizable performance of the methane sensor. It was found that methane, ethane, propane and pentane could be distinguished clearly. Its methane sensing properties, including improved sensitivity, selectivity, stability and recognition demonstrated the TiO2/SnO2 materials to be promising candidates for constructing a cataluminescence‐based gas sensor that could be used for detecting explosive gas contaminants. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

7.
A novel and sensitive gas sensor was developed for the determination of benzene based on its cataluminescence (CTL) by oxidation in air on the surface of hollow magnesium silicate spheres. Luminescence characteristics and optimum conditions were investigated. Results indicated that the as‐prepared magnesium silicate hollow spheres exhibited outstanding CTL properties such as stable intensity, high signal/noise values, and short response and recovery times. Under optimized conditions, benzene exhibited a broad linear range of 1–4500 ppm, with a correlation coefficient of 0.9946 and a limit of detection (signal‐to‐noise ratio (S/N) = 3) of 0.6 ppm, which was below the standard permitted concentration. The relative standard deviation (RSD) for 100 ppm benzene was 4.3% (n = 6). Furthermore, the gas sensor system showed outstanding selectivity for benzene compared with nine other common volatile organic compounds (VOCs). The proposed gas sensor showed good characteristics of high selectivity, fast response time and long lifetime, which suggested the promising application of magnesium silicate hollow spheres as a novel highly efficient CTL sensing material. The mechanism for the improved performance was also discussed based on the experimental results. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

8.
硫化氢与细胞的增殖和凋亡   总被引:1,自引:1,他引:1  
Yang GD  Wang R 《生理学报》2007,59(2):133-140
硫化氢是内源性气体分子家族中的一员,是一种气体递质(gasotransmitter)。近年来,内源性硫化氢的产生及生理意义已经被认识,其代谢异常与许多疾病有关。本文综述了最近发现的硫化氢对细胞增殖和凋亡的调节作用,并重点概述硫化氢细胞效应的分子机制,包括丝裂原活化蛋白激酶、细胞周期相关激酶、细胞死亡相关基因以及离子通道等的改变。对硫化氢调节细胞生长或死亡的深入了解将为新药设计及许多疾病的治疗提供新的思路。  相似文献   

9.
S,N co‐doped carbon quantum dots (N,S‐CQDs) with super high quantum yield (79%) were prepared by the hydrothermal method and characterized by transmission electron microscopy, photoluminescence, UV–Vis spectroscopy and Fourier transformed infrared spectroscopy. N,S‐CQDs can enhance the chemiluminescence intensity of a luminol–H2O2 system. The possible mechanism of the luminol–H2O2–(N,S‐CQDs) was illustrated by using chemiluminescence, photoluminescence and ultraviolet analysis. Ranitidine can quench the chemiluminescence intensity of a luminol–H2O2–N,S‐CQDs system. So, a novel flow‐injection chemiluminescence method was designed to determine ranitidine within a linear range of 0.5–50 μg ml?1 and a detection limit of 0.12 μg ml?1. The method shows promising application prospects.  相似文献   

10.
Carbon dots (CDs), as an attractive zero-dimensional carbon nanomaterial with unique photoluminescent merits, have recently exhibited significant application potential in gas sensing as a result of their excellent optical/electronic characteristics, high chemical/thermal stability, and tunable surface states. CDs exhibit strong light absorption in the ultraviolet range and tunable photoluminescence characteristics in the visible range, which makes CDs an effective tool for optical sensing applications. Optical gas sensor based on CDs have been investigated, which generally responds to the target gas by corresponding changes in optical absorption or fluorescence. Moreover, electrical gas sensor and quartz crystal microbalance sensor whose sensing layer involves CDs have also been designed. Electrical gas sensor exhibits an increase or a decrease in electrical current, capacitance, or conductance once exposed to the target gas. Quartz crystal microbalance sensor responds to the target gas with a frequency shift. CDs greatly promote the absorption of the target gas and improve the sensitivity of both sensors. In this review, we aim to summarize different types of gas sensors involving CDs, and sensing performances of these sensors for monitoring diverse gases or vapors, as well as the mechanisms of CDs in different types of sensors. Moreover, this review provides the prospect of the potential development of CDs based gas sensors.  相似文献   

11.
以拟南芥野生型、SOS突变体印tsosl、Atsos2和Atsos3)、H2S合成相关酶L-/D-半胱氨酸脱巯基酶(L-/D-CDes)基因缺失突变体(Atl-cdes和Atd-cdes)和过表达株系(OEL—CDes和OED-CDes)为材料研究了H,s和SOS信号转导途径在盐胁迫诱导拟南芥气孔关闭中的作用及其相互关系。结果表明,盐胁迫能够引起拟南芥叶片H,S含量、L-/D-CDes活性及其基因表达量显著升高,诱导野生型拟南芥和OEL—CDes和OED.CDes叶片气孔关闭,但对Atl-cdes和Atd-cdes气孔开度无显著影响;而H2S清除剂次牛磺酸(hypotaurine,HT)可减弱盐胁迫诱导的拟南芥气孔关闭的作用,表明H2S参与盐胁迫诱导的拟南芥气孔关闭过程。外源H2S诱导野生型拟南芥气孔关闭,但对SOS突变体气孔开度无显著影响;同时盐胁迫下Atsosl、Atsos2和Atsos3亦表现出H2S含量及L-/D-CDes活性显著升高,且与野生型相比,盐胁迫对Atl-cdes和Atd-cdes叶片AtSOS基因表达量无显著影响。表明盐胁迫诱导气孔关闭过程中H2S位于SOS上游。  相似文献   

12.
One‐dimensional (1D) hierarchical structures composed of Ni3S2 nanosheets grown on carbon nanotube (CNT) backbone (denoted as CNT@Ni3S2) are fabricated by a rational multi‐step transformation route. The first step involves coating the CNT backbone with a layer of silica to form CNT@SiO2, which serves as the substrate for the growth of nickel silicate (NiSilicate) nanosheets in the second step to form CNT@SiO2@NiSilicate core‐double shell 1D structures. Finally the as‐formed CNT@SiO2@NiSilicate 1D structures are converted into CNT‐supported Ni3S2 nanosheets via hydrothermal treatment in the presence of Na2S. Simultaneously the intermediate silica layer is eliminated during the hydrothermal treatment, leading to the formation of CNT@Ni3S2 nanostructures. Because of the unique hybrid nano‐architecture, the as‐prepared 1D hierarchical structure is shown to exhibit excellent performance in both supercapacitors and photocatalytic H2 production.  相似文献   

13.
近年来,内源性H_2S作为第3种被发现的新型气体信号分子,其生理学作用逐渐受到研究者的重视.在哺乳动物体内,H_2S与血红素蛋白的结合有两种方式,一种是H_2S直接键合血红素中心Fe形成Fe-H_2S复合物;另一种则是H_2S修饰血红素卟啉环,形成硫代血红素结构.我们选用肌红蛋白(myoglobin,Mb)作为研究对象,通过点突变技术改变了血红素活性中心结构,结合紫外-可见光谱学以及X-射线晶体学,研究了H_2S与不同突变型Mb反应后的光谱和结构变化.结果显示:血红素中心近、远端腔微环境的变化,如腔体极性、氢键数目、氢键位置等因素直接影响蛋白质与H_2S的结合,以及硫代血红素(sulfheme)的形成.这些结果为研究血红素蛋白参与内源性H_2S代谢机理提供了重要的实验数据.  相似文献   

14.
为探究H2S信号在苜蓿(Medicago sativa)体内调节气孔运动的作用,及在此过程中H2S与Ca2+的关系,以蒺藜苜蓿(Medicago truncatula)的野生型和钙离子转运体突变体为试验材料,分别从转录水平、细胞水平和生理水平开展研究。采用qRT-PCR比较相关基因的表达量变化、荧光探针显示体内Ca2+含量、电极法测定H2S含量、光学显微镜观察和测量气孔孔径等。结果表明:蒺藜苜蓿突变体NF3011和NF2734体内H2S的含量与野生型相比极显著降低(P<0.01);H2S信号在一定程度上抑制钙离子转运体编码基因MTR_6g027580的表达;外源生理浓度H2S熏蒸可诱导蒺藜苜蓿气孔关闭,与Ca2+通道阻断剂LaCl3联合处理对野生型气孔运动未产生影响,而在突变体中的结果截然相反;利用荧光探针测定保卫细胞内的Ca2+含量,所得结果与气孔孔径的变化规律完全一致。综上所述,H2S信号促进叶片保卫细胞内Ca2+的含量增加,最终表现为植物气孔孔径变小,在此过程中胞内Ca2+含量变化主要通过Ca2+转运体进行,少部分依赖Ca2+离子通道。该研究结果不仅在理论上丰富了H2S信号的作用机制,更具应用于苜蓿生产实践并推广于其他作物的潜力。  相似文献   

15.
硫化氢(Hydrogen sulfide,H2S)是植物新型气体信号分子,钙离子(Calcium,Ca2+)为重要的第二信使,两者在植物逆境响应中分别发挥着重要作用。为明确胞质Ca2+在外源H2S促进盐碱胁迫下作物种子萌发中的作用,以裸燕麦(Avena nude)为材料,采用培养皿培养,以混合盐碱(NaCl、Na2SO4、Na2CO3、NaHCO3的摩尔比为12:8:1:9)模拟甘肃裸燕麦种植地盐碱环境,蒸馏水为对照,测定了胞外Ca2+螯合剂乙二醇-双-(2-氨基乙醚)四乙酸(EGTA)、质膜Ca2+通道阻断剂氯化镧(LaCl3)、液泡Ca2+释放抑制剂钌红(RR)和内质网钙泵阻断剂毒胡萝卜素(Thaps)分别与H2S供体硫氢化钠(NaHS)共处理下种子的发芽势、发芽率、发芽指数、活力指数、平均发芽速率、胚根长和胚芽长7个发芽指标,利用隶属函数分析方法综合评价胞质Ca2+对H2S缓解盐碱胁迫抑制种子萌发的影响。结果表明,随着盐碱胁迫浓度增大,裸燕麦种子的发芽势、发芽率、发芽指数、活力指数、平均发芽速率、胚根长和胚芽长显著下降。与对照相比,15~75 mmol·L-1盐碱胁迫导致裸燕麦种子萌发的隶属函数综合评价值(D)显著降低,30 mmol·L-1盐碱胁迫下D值下降了73.1%;100~1 000 μmol·L-1 NaHS不同程度提高了裸燕麦种子萌发的D值,且100 μmol·L-1 NaHS缓解30 mmol·L-1盐碱胁迫下D值下降的作用最大;EGTA、LaCl3和RR均显著逆转了100 μmol·L-1 NaHS对30 mmol·L-1盐碱胁迫下D值下降的缓解作用,而Thaps对NaHS的作用无显著影响。表明胞质Ca2+参与外源H2S促进盐碱胁迫下裸燕麦种子萌发的信号传导过程,且胞质Ca2+主要来源于胞外Ca2+的内流和液泡中Ca2+的释放。  相似文献   

16.
High homocysteine (HCy) levels are associated with lymphocyte‐mediated inflammatory responses that are sometimes in turn related to hypoxia. Because adenosine is a potent lymphocyte suppressor produced in hypoxic conditions and shares metabolic pathways with HCy, we addressed the influence of high HCy levels on the hypoxia‐induced, adenosine‐mediated, alteration of lymphocyte viability. We treated mitogen‐stimulated human lymphocytes isolated from healthy individuals and the human lymphoma T‐cell line CEM with cobalt chloride (CoCl2)to reproduce hypoxia. We found that CoCl2‐altered cell viability was dose‐dependently reversed using HCy. In turn, the HCy effect was inhibited using DL‐propargylglycine, a specific inhibitor of the hydrogen sulphide (H2S)‐synthesizing enzyme cystathionine‐γ‐lyase involved in HCy catabolism. We then addressed the intracellular metabolic pathway of adenosine and HCy, and the role of the adenosine A2A receptor (A2AR). We observed that: (i) hypoxic conditions lowered the intracellular concentration of HCy by increasing adenosine production, which resulted in high A2AR expression and 3′, 5′‐cyclic adenosine monophosphate production; (ii) increasing intracellular HCy concentration reversed the hypoxia‐induced adenosinergic signalling despite high adenosine concentration by promoting both S‐adenosylhomocysteine and H2S production; (iii) DL‐propargylglycine that inhibits H2S production abolished the HCy effect. Together, these data suggest that high HCy levels prevent, via H2S production and the resulting down‐regulation of A2AR expression, the hypoxia‐induced adenosinergic alteration of lymphocyte viability. We point out the relevance of these mechanisms in the pathophysiology of cardiovascular diseases.  相似文献   

17.
Ischemia-reperfusion (I/R) injury is a multifactorial process triggered when an organ is subjected to transiently reduced blood supply. The result is a cascade of pathological complications and organ damage due to the production of reactive oxygen species following reperfusion. The present study aims to evaluate the role of activated calcium-sensing receptor (CaR)-cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway in I/R injury. Firstly, an I/R rat model with CSE knockout was constructed. Transthoracic echocardiography, TTC and HE staining were performed to determine the cardiac function of rats following I/R Injury, followed by TUNEL staining observation on apoptosis. Besides, with the attempt to better elucidate how CaR-CSE/H2S affects I/R, in-vitro culture of human coronary artery endothelial cells (HCAECs) was conducted with gadolinium chloride (GdCl3, a CaR agonist), H2O2, siRNA against CSE (siCSE), or W7 (a CaM inhibitor). The interaction between CSE and CaM was subsequently detected. Plasma oxidative stress indexes, H2S and CSE, and apoptosis-related proteins were all analyzed following cell apoptosis. We found that H2S elevation led to the improvement whereas CSE knockdown decreased cardiac function in rats with I/R injury. Moreover, oxidative stress injury in I/R rats with CSE knockout was aggravated, while the increased expression of H2S and CSE in the aortic tissues resulted in alleviated the oxidative stress injury. Moreover, increased H2S and CSE levels were found to inhibit cell apoptotic ability in the aortic tissues after I/R injury, thus attenuating oxidative stress injury, accompanied by inhibited expression of apoptosis-related proteins. In HCAECs following oxidative stress treatment, siCSE and CaM inhibitor were observed to reverse the protection of CaR agonist. Coimmunoprecipitation assay revealed the interaction between CSE and CaM. Taken together, all above-mentioned data provides evidence that activation of the CaR-CSE/H2S pathway may confer a potent protective effect in cardiac I/R injury.  相似文献   

18.
目的:探讨吸入外源性H_2S对心跳骤停复苏大鼠脑血流动力学及神经功能的影响。方法:选择成年雄性SD大鼠18只,随机分为假手术组(sham,n=6)、窒息导致心跳骤停复苏组(CA,n=6)、心跳骤停复苏+H_2S组(H_2S,n=6),观察H_2S对心跳骤停复苏大鼠脑血流的影响。选择成年雄性SD大鼠45只,随机分为sham组(n=5)、CA(n=20)和H_2S组(n=20),观察H_2S对心跳骤停复苏大鼠神经功能和存活率的影响。结果:CA组与H_2S组在ROSC后MAP和CPP均快速上升,远高于基础值(P0.05);而后两组MAP和CPP均缓慢下降,实验结束时,明显低于基础值(P0.05)。两组间比较差异无统计学意义(P0.05)。CA组与H_2S组CBF曲线在ROSC后上升至峰值,随后逐渐下降,两组在峰值无明显差异,但H_2S组CBF减少量显著少于CA组(P0.05)。而在CVR曲线,在实验最后,CA组CVR值仍明显高于基础值(P0.05),而H_2S组基本降至基础值,明显低于CA组(P0.05)。H_2S组的14天存活率(80%)明显高于CA组(50%,P0.05)。在胶带移除实验(tape removal test,TRT)所需时间上,CA组与H_2S组在第1天、第3天及第14天都存在显著差异(P0.05)。H_2S组第14天海马CA1区神经元存活数(33±8)明显多于CA组(20±6,P0.05),但仍较假手术组少(53±10,P0.05)。结论:外源性H_2S吸入对大鼠心跳骤停复苏后MAP及CPP无明显影响。外源性H_2S通过降低CVR,改善CBF,从而改善大鼠心跳骤停复苏后的脑循环。外源性H_2S能明显提高心跳骤停复苏后大鼠的存活率,降低TRT所需时间,同时显著增加海马CA1区神经元的存活,改善大鼠心跳骤停复苏后神经功能转归。  相似文献   

19.
Electrogenerated chemiluminescence (ECL) of thiol‐capped CdTe quantum dots (QDs) in aqueous solution was greatly enhanced by PDDA‐protected graphene (P‐GR) film that were used for the sensitive detection of H2O2. When the potential was cycled between 0 and ?2.3 V, two ECL peaks were observed at ?1.1 (ECL‐1) and ?1.4 V (ECL‐2) in pH 11.0, 0.1 M phosphate buffer solution (PBS), respectively. The electron‐transfer reaction between individual electrochemically‐reduced CdTe nanocrystal species and oxidant coreactants (H2O2 or reduced dissolved oxygen) led to the production of ECL‐1. While mass nanocrystals packed densely in the film were reduced electrochemically, assembly of reduced nanocrystal species reacted with coreactants to produce an ECL‐2 signal. ECL‐1 showed higher sensitivity for the detection of H2O2 concentrations than that of ECL‐2. Further, P‐GR film not only enhanced ECL intensity of CdTe QDs but also decreased its onset potential. Thus, a novel CdTe QDs ECL sensor was developed for sensing H2O2. Light intensity was linearly proportional to the concentration of H2O2 between 1.0 × 10?5 and 2.0 x 10‐7 mol L?1 with a detection limit of 9.8 x 10?8 mol L?1. The P‐GR thin‐film modified glassy carbon electrode (GCE) displayed acceptable reproducibility and long‐term stability. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

20.
目的:观察新型气体信号分子硫化氢(H2S)对血小板L-精氨酸(L-Arg)转运的影响以探讨硫化氢对血小板功能的影响。方法:采用饱和H2S溶液作为H2S供体,制备大鼠富血小板血浆,使用含有不同浓度硫化氢的孵育液对大鼠血小板进行预孵育,检测同位素标记的L-Arg在血小板转运的情况,以判断硫化氢对血小板精氨酸转运的影响。结果:不同浓度的H2S(6.25、12.5、25、50、100μmol/L)存在时均血小板对L-Arg转运速率均低于对照组;H2S可以快速降低血小板L-Arg转运速率;转运动力学显示H2S显著降低血小板L-Arg转运Vmax(P0.05),但对Km值无明显影响。结论:硫化氢可能通过快速改变血小板L-精氨酸转运系统功能影响血小板功能。  相似文献   

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