28 research outputs found

    Colorimetric Sensors of Hg2+ Ion Based on Functionalized Gold and Silver Nanoparticles

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    Monitoring the levels of toxic Hg2+ metal ion in aquatic environment is important issue because this ion can have adverse effect in human health and environment. Therefore, detection of Hg2+ ion in water is very important issue for improving human health and water quality. Metallic nanoparticles such as gold and silver nanoparticles (AuNPs & AgNPs) have received much attention due to their colorimetric properties as well as localized surface plasmon resonance (LSPR) properties. AuNPs and AgNPs can easily change their colour (AuNPs: Red to Pink/Blue; AgNPs: Yellow to orange/red) which is easily discriminate by visual inspection. Functionalization of AuNPs and AgNPs offers an excellent application in many scientific worlds as the choice of ligands/functionalizing groups is outmost importance for their colloidal stability and function of the nanoparticles. In this review, we have discussed the colorimetric sensors of gold and silver nanoparticles based on functionalization of organic ligands, polymers, amino acid, and proteins for the detection of Hg2+ ion in aqueous medium

    Physiological responses of sub1A QTL under induced dehydration stress for varying days in rice

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    This study analysed the rice genotype with sub1A quantitative trait loci that may interact with ongoing exposure of dehydration. cv. Swarna Sub1 had more nutrients efficiency with increased membrane permeability than cv. Swarna. sub1A QTL with its expression to water / osmotic deficit, however, indirectly to impede the oxidative stress under dehydration might help cv. Swarna Sub1. At maximum dehydration cv. Swarna Sub1 had 1.12 fold excess electrolyte leakages than cv. Swarna under dehydration. cv. Swarna Sub1 had better Nicotinamide adenine dinucleotide phosphate-malic enzyme activity to secure carbon dioxide exchange. A proportional increase in enzyme activity all through dehydration stress maximize under light in cv. Swarna Sub1. At maximum dehydration cv. Swarna Sub1 at saturating substrate concentration was increased by 1.12 fold than other cultivar. The ratio of glutathione (GSH:GSSG) more depleted in cv. Swarna Sub1 through the dehydration period. cv. Swarna could be more promising to retrieve the activity by 1.80 fold than cv. Swarna Sub1 under maximum dehydration. Dehydroascorbate reductase activity was also maintained in cv. Swarna with 1.20 fold ahead than cv. Swarna Sub1 under same condition. As a biomarker of oxidative stress cv. Swarna Sub1 appeared to be less sensitive with the loss of protein oxidation, however, recorded with 25% less carbonyl content than cv. Swarna. Both the genotypes had scored a significant sensitivity with tissue specific distribution for reactive oxygen species as detected by histochemical assay

    Modalities of NADP-malic enzyme activities under light and darkness indicate its regulation with reference to C4 weed

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    NADP –ME is the key enzyme for decarboxylation reactions in C4 CO2 concentration pathways. So, Amaranthus viridis has been evaluated with regards to photosynthetic NADP-malic enzyme for its response under light and darkness. Illumination (1000–1200 µEm-2s-1) for 40 minutes under 2 mM bicarbonate (HCO3-) sensitivity increased activity by 1.97 & 3.77-fold over darkness under 4.0 mM and 0.01 mM malate respectively. Limiting (0.01 mM) and saturated (4.0 mM) malate concentration had significant changes in enzyme activities. The different kinetic parameters indicated had the feedback inhibition under illumination. The activity with the inducer (citrate and succinate) and inhibitor (pyruvate and oxalate) was significant with substrate concentrations. Dithiol had reduced the activity by inhibition of the diminishing effect of light activation treatment. Therefore, NADP-ME is stringently regulated by redox changes with illumination as a key factor. Moreover, the pattern of polymorphic gene expression may be supportive in molecular modulation under light/darkness. This study may support the role of NADP-ME as a biomarker for C4 weed species under oxidative stress through light/darkness

    Cellular response of oxidative stress when sub1A QTL of rice receives water deficit stress

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    In this experiment, sub1A quantitative trait loci (sub1A QTL) of rice were evaluated for dehydration responses through different aspects of cellular responses. Through variations of dehydration exposure, rice seedlings recorded a significant increase in superoxide (O2.-) and hydrogen peroxide (H2O2), the former by 1.80 fold and the latter by 2.10 fold. Nicotinamide adenine dinucleotide phosphate oxidase activity fairly correlated with lipid peroxidation (r = 1.96). Both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) had similar IC50 values over the control at p ? 0.05. Reducing power of the extract had 1.31 fold increase. The antioxidant moieties like total phenolics and flavonoids were 1.04 and 1.23 fold upregulated under stress. On the other hand anthocyanin and glutathione (GSH) did not vary much under stress except at maximum duration of stress. Superoxide dismutase (SOD) was initially stable but maximized at 8 days by 1.30 fold increase. On the contrary, guaiacol peroxidase (GPX) was seen to be downregulated by 40.94% all through the days of stress. Catalase (CAT) activity followed a similar trend, but was not significant as compared to control

    The direct and indirect impact of SARS-CoV-2 infections on neonates: a series of 26 cases in Bangladesh

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    Background: The impact of SARS-CoV-2 on neonates remains largely unknown in low- and middle-income countries (LMICs). We provide an epidemiologic and clinical report of SARS-CoV-2 infections in neonates hospitalized in Bangladesh. Methods: Outborn neonates admitted to Dhaka Shishu Hospital, a tertiary-care referral hospital, between 29 March and 1 July were screened for SARS-CoV-2. We reviewed clinical data, including chest radiograph and laboratory reports, and conducted SARS-CoV-2 genome sequencing. Patients were followed-up for 27–75 days. A subset of caregivers was also tested. Results: Of 83 neonates tested, 26 were positive (median age 8 days). Most neonates were admitted with diagnosis unrelated to SARS-CoV-2: 11 presented with serious non-communicable diseases, 7 with early-onset sepsis, 5 with late-onset sepsis and 2 with pneumonia. In 3 of 5 chest radiograph, infiltrates and ground-glass or patchy opacities were noted. Two neonates developed metabolic acidosis, one developed disseminated intravascular coagulation. Most SARS-CoV-2 positive neonates were referred to government-designated COVID-19 hospitals, leading to gaps in treatment. Twenty-three neonates could be followed-up: 12 were healthy, 8 died and 3 were still seeking medical care. Of 9 caregivers tested, 8 were positive. Conclusions: SARS-CoV-2 may have serious adverse effects on children born in LMICs. The virus likely contributed directly to two deaths, but the remaining 6 neonates who died had serious comorbidities. Positive SARS-CoV-2 test results led to gaps in immediate clinical care for other morbidities, which likely contributed to adverse outcomes. This case series emphasizes the need to understand COVID-19 in neonates in LMICs and its indirect impacts

    Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

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    无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216
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