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1.
Sci Data ; 11(1): 209, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38360806

RESUMO

Reservoirs play a crucial role in regulating water availability and enhancing water security. Here, we develop NASA's Visible Infrared Imaging Radiometer Suite (VIIRS) based Global Water Reservoir (GWR) product, consisting of measurements of reservoir area, elevation, storage, evaporation rate, and evaporation loss for 164 large global reservoirs. The dataset is available at 8-day and monthly temporal resolutions. Since the Moderate Resolution Imaging Spectroradiometer (MODIS) is close to the end of its life, we further evaluated the consistency between MODIS and VIIRS-based GWR to ensure continuity to the 20+ year MODIS GWR product. Independent assessment of VIIRS reservoir storage (8-day) retrievals against in-situ measurements shows an average of R2 = 0.84, RMSE = 0.47 km3, and NRMSE = 16.45%. The evaporation rate has an average of R2 = 0.56, RMSE = 1.32 mm/day, and NRMSE = 28.14%. Furthermore, results show good consistency (R2 ≥ 0.90) between the VIIRS and MODIS-based product components, confirming that long-term data continuity can be achieved. This dataset can provide valuable insights for long-term trend analysis, hydrological modeling, and understanding hydroclimatic extremes in the context of reservoirs.

2.
Int J Biol Macromol ; 258(Pt 1): 128774, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38096934

RESUMO

Real-time monitoring of low temperatures (usually below 0 °C) or cold environments is a specific requirement that finds its high demand in the aerospace, pharmaceutical, food, and beverage industries to maintain the temperature at high altitudes or in refrigerators and cold storage. In general, this purpose is achieved by using a sub-zero temperature sensor coupled with a control system. However, the market available such temperature sensors are very expensive, and bulky, thus not being suitable for portable operation, and also they suffer from poor accuracy. Therefore, the development of high-performance, low-cost, lightweight, and portable sub-zero temperature sensors is highly desired. In our recent work, we developed such sensors and integrated them with auxiliary electronics to demonstrate their wireless operation for the continuous and real-time monitoring of cold environments. So, in order to obtain low-cost sensors a cost-effective inkjet printing technology was employed for the fabrication of devices. A lightweight polydimethylsiloxane (PDMS) was used as the substrate and an electrically conducting graphene nanocomposite was used as the temperature-sensing material. To obtain a functional graphene nanocomposite film with a thickness of 530 nm and a conductivity of ~189 S m-1, the printed graphene nanocomposite was photonically sintered using a xenon flash lamp. This step was crucial for obtaining a sensor on the soft PDMS platform. The graphene nanocomposite film exhibited a positive temperature coefficient resistance value of approximately 0.119 %/°C, and its resistance values varied almost linearly (with an Adjusted R2 value (model accuracy) of 0.99) with temperature within the operating range of -30 °C to 80 °C. The sensor was properly encapsulated for protection without significantly affecting its performance. The sensors demonstrated sufficient flexibility, with a bending radius of 20 mm, and sustained 500 continuous bending cycles. Finally, the real-time operation of the sensors was demonstrated by wirelessly transmitting and monitoring the temperature over a smartphone platform.


Assuntos
Grafite , Temperatura , Eletrônica , Condutividade Elétrica
3.
Fitoterapia ; 171: 105684, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37751799

RESUMO

Houttuynia cordata (Thunb.), an important medicinal plant of Northeast India, Korea, and China, is used to treat various ailments and for anticancer research. Knowing its traditional practices, we are interested in the mode-of-action of HCT on HepG2 to co-relate the traditional practice with modern drug therapeutics. UPLC-Q-ToF-Ms analysis of HCT reveals identification of 14 metabolites. Network pharmacology analysis of the 14 compounds showed interaction with 232 different targets with their potential involvement in hepatocellular carcinoma. Whole extracts impart cytotoxicity on variety of cell lines including HepG2. There was a significant morphological alteration in treated HepG2 cells due to impairment of cytoskeletal components like ß and γ- tubulin. Arrest at G1-S checkpoint was clearly indicated downregulation of Cyclin D1. The root extracts actuated apoptosis in HepG2 as evident from altered mitochondrial membrane potential, Annexin V- FITC, BrdU-PI, AO/EtBr assays, and modulations of apoptotic protein expression but without ROS generation. Whole extracts caused abrogation of epithelial to mesenchymal transition with repression of Snail, N-Cadherin, Vimentin, MMP-9, and upregulation of Pan-Cadherin. Pathway analysis found GSK-3ß in Wnt/ß-Catenin signaling cascade to be involved through Hepatocellular carcinoma (hsa05225) pathway. The GSK-3ß/ß-Catenin/PDL-1 signaling was found to be inhibited with the downregulation of pathway components. This was further confirmed by application of EGF, an inducer of the GSK-3ß/ß-Catenin pathway that neutralized the effect of Houttuynia cordata (Thunb.) root extract on the said pathway. Network pharmacology analysis also confirms the synergy network with botanical-bioactive-target-disease which showed Kaempferol to have the highest degree of association with the said pathway.


Assuntos
Carcinoma Hepatocelular , Houttuynia , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Glicogênio Sintase Quinase 3 beta/farmacologia , Houttuynia/metabolismo , Linhagem Celular Tumoral , beta Catenina/metabolismo , beta Catenina/farmacologia , Espectrometria de Massas em Tandem , Transição Epitelial-Mesenquimal , Proliferação de Células , Estrutura Molecular , Via de Sinalização Wnt , Neoplasias Hepáticas/tratamento farmacológico , Apoptose
4.
Mol Ther Nucleic Acids ; 32: 203-228, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37078062

RESUMO

Phosphorodiamidate morpholino oligonucleotide (PMO)-based antisense reagents cannot enter cells without the help of a delivery technique, which limits their clinical applications. To overcome this problem, self-transfecting guanidinium-linked morpholino (GMO)-PMO or PMO-GMO chimeras have been explored as antisense agents. GMO facilitates cellular internalization and participates in Watson-Crick base pairing. Targeting NANOG in MCF7 cells resulted in decline of the whole epithelial to mesenchymal transition (EMT) and stemness pathway, evident through its phenotypic manifestations, all of which were promulgated in combination with Taxol due to downregulation of MDR1 and ABCG2. GMO-PMO-mediated knockdown of no tail gene resulted in desired phenotypes in zebrafish even upon delivery after 16-cell stages. In BALB/c mice, 4T1 allografts were found to regress via intra-tumoral administration of NANOG GMO-PMO antisense oligonucleotides (ASOs), which was associated with occurrence of necrotic regions. GMO-PMO-mediated tumor regression restored histopathological damage in liver, kidney, and spleen caused by 4T1 mammary carcinoma. Serum parameters of systemic toxicity indicated that GMO-PMO chimeras are safe. To the best of our knowledge, self-transfecting antisense reagent is the first report since the discovery of guanidinium-linked DNA (DNG), which could be useful as a combination cancer therapy and, in principle, can render inhibition of any target gene without using any delivery vehicle.

5.
J Environ Manage ; 326(Pt A): 116727, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372040

RESUMO

In this study, Black Soldier Fly Larvae (BSFL)-based technology has been proposed and tested for treatment and valorization of human faeces, food waste and a mixture of 75% human faeces with 25% food waste. Experiments were conducted between 15 and 45 °C and 55-75% relative humidity. BSFL's performance for the degradation of the mixed waste was significantly better than their performances when used for the degradation of either human faeces or food waste fed alone, primarily due to the availability of more conducive pH, and better microbial and nutrient balance. The abiotic factors, temperature and relative humidity impacted the decomposition rate and weight gain pattern of BSFL when they were fed on the waste streams. The results showed that the optimum conditions to conduct the proposed BSFL-based treatment was 31-35 °C and 55-75% RH. The protein content in the BSFL was not impacted significantly by the quality of the waste stream, whereas the fat content varied substantially. The abiotic factors also impacted the protein and fat content of BSFL. The investigation led to the estimation of the decomposition rates over a wide range of temperature and relative humidity conditions, which could be useful for the design of large-scale BSFL-based treatment plants.


Assuntos
Dípteros , Eliminação de Resíduos , Animais , Humanos , Larva , Alimentos , Fezes
6.
Chemosphere ; 305: 135369, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35718039

RESUMO

To effectively remove trace concentration of potential cancer-causing Cr(VI) from impaired drinking water, a novel hybrid material was synthesized through an in-situ synthesis process by dispersing ferrous sulfide nanoparticles within an anion exchanger. Characterization studies revealed that the hybrid material, named hybrid ferrous sulfide impregnated anion exchanger (HISIIX), contained uniformly distributed ferrous sulfide nanoparticles of size 10-40 nm within the anion exchanger host. Apart from FeS2 nanoparticles, it also included nanoparticles of FeO and FeOOH. The incorporation of ferrous sulfide nanoparticles within the anion exchanger contributed to the significant differences in the Cr(VI) uptake capacity of HISIIX. Validation studies using fixed-bed column proved that HISIIX had significantly high Cr(VI) uptake capacity and was able to run for 4200 bed volumes (BVs) before a breakthrough of 50 µg L-1 when subjected to a synthetic aqueous solution containing 200 µg L-1 Cr(VI). Cr(VI) uptake capacity of the parent anion exchanger and HISIIX were determined to be 1.39 mg g-1 and 3.44 mg g-1, respectively, when the columns were allowed to run until exhaustion. Ferrous sulfide nanoparticles acted as a reducing agent transforming Cr(VI) anions into Cr(III) precipitates. It also produced sites for further removal of Cr(VI) anions through ligand sorption upon oxidation. The anion exchanger substrate attracted anions selectively via the Donnan membrane principle, resulting in a synergy of three different processes - ion exchange, redox reaction, and ligand sorption that gave the HISIIX a high capacity for the selective Cr(VI) removal from contaminated water.


Assuntos
Poluentes Químicos da Água , Adsorção , Ânions/química , Cromo/química , Compostos Ferrosos , Concentração de Íons de Hidrogênio , Ligantes , Água , Poluentes Químicos da Água/química
7.
J Environ Manage ; 302(Pt A): 114060, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34749077

RESUMO

The commingled nature of the municipal solid waste in many developing nations is one of the primary reasons behind the failure to its successful management. Although there are technologies to effectively treat and process well-segregated and classified waste, they are ineffective in managing the commingled waste. Commingled waste has neither calorific value enough to support waste-to-energy operations nor is it suitable for producing quality compost to generate market value. In this article, a novel Black Soldier Fly Larva (BSFL) -based technology has been proposed and tested to auto-segregate and treat the biodegradable fraction of the Commingled Municipal Solid Waste (CMSW). Several BSFL feeding experiments on five different CMSW compositions were conducted at various temperatures and relative humidity conditions. BSFL could selectively consume the biodegradable fraction of the CMSW to convert it into its body mass and separate itself from the rest of the waste, which mainly consisted of inert and recyclable waste fractions that can be further treated using appropriate waste treatment technology. The mature larvae or the pre-pupae grown at the expense of the biodegradable waste fraction can find several commercial uses. The larvae's consumption rate and weight gain were dependent on the environmental conditions; 30 °C and relative humidity of 65-75% provided the highest consumption rate and most significant weight gain. The batch experiments in the laboratory proved that BSFL could be promising for the treatment of CMSW. The experimental data presented may help design a process for further scaling up an effective treatment method for CMSW, which might benefit many developing nations in managing their waste effectively and economically.


Assuntos
Compostagem , Dípteros , Animais , Larva , Resíduos Sólidos
8.
JMIR Public Health Surveill ; 7(11): e29020, 2021 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-34766914

RESUMO

BACKGROUND: Population-based health surveys are typically conducted using face-to-face household interviews in low- and middle-income countries (LMICs). However, telephone-based surveys are cheaper, faster, and can provide greater access to hard-to-reach or remote populations. The rapid growth in mobile phone ownership in LMICs provides a unique opportunity to implement novel data collection methods for population health surveys. OBJECTIVE: This study aims to describe the development and population representativeness of a mobile phone survey measuring live poultry exposure in urban Bangladesh. METHODS: A population-based, cross-sectional, mobile phone survey was conducted between September and November 2019 in North and South Dhaka City Corporations (DCC), Bangladesh, to measure live poultry exposure using a stratified probability sampling design. Data were collected using a computer-assisted telephone interview platform. The call operational data were summarized, and the participant data were weighted by age, sex, and education to the 2011 census. The demographic distribution of the weighted sample was compared with external sources to assess population representativeness. RESULTS: A total of 5486 unique mobile phone numbers were dialed, with 1047 respondents completing the survey. The survey had an overall response rate of 52.2% (1047/2006) and a co-operation rate of 89.0% (1047/1176). Initial results comparing the sociodemographic profile of the survey sample to the census population showed that mobile phone sampling slightly underrepresented older individuals and overrepresented those with higher secondary education. After weighting, the demographic profile of the sample population matched well with the latest DCC census population profile. CONCLUSIONS: Probability-based mobile phone survey sampling and data collection methods produced a population-representative sample with minimal adjustment in DCC, Bangladesh. Mobile phone-based surveys can offer an efficient, economic, and robust way to conduct surveillance for population health outcomes, which has important implications for improving population health surveillance in LMICs.


Assuntos
Telefone Celular , Saúde da População , Animais , Bangladesh/epidemiologia , Estudos Transversais , Países em Desenvolvimento , Humanos , Aves Domésticas , Inquéritos e Questionários
9.
Sci Rep ; 11(1): 21880, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34750452

RESUMO

Avian influenza is endemic in Bangladesh, where greater than 90% of poultry are marketed through live poultry markets (LPMs). We conducted a population-based cross-sectional mobile telephone survey in urban Dhaka, Bangladesh to investigate the frequency and patterns of human exposure to live poultry in LPMs and at home. Among 1047 urban residents surveyed, 74.2% (95% CI 70.9-77.2) reported exposure to live poultry in the past year, with the majority of exposure occurring on a weekly basis. While visiting LPMs was less common amongst females (40.3%, 95% CI 35.0-45.8) than males (58.9%, 95% CI 54.0-63.5), females reported greater poultry exposure through food preparation, including defeathering (13.2%, 95% CI 9.5-17.9) and eviscerating (14.8%, 95% CI 11.2-19.4) (p < 0.001). A large proportion of the urban population is frequently exposed to live poultry in a setting where avian influenza viruses are endemic in LPMs. There is thus not only ample opportunity for spillover of avian influenza infections into humans in Dhaka, Bangladesh, but also greater potential for viral reassortment which could generate novel strains with pandemic potential.


Assuntos
Influenza Aviária/epidemiologia , Influenza Aviária/transmissão , Influenza Humana/epidemiologia , Influenza Humana/transmissão , Aves Domésticas/virologia , Adolescente , Adulto , Idoso , Animais , Bangladesh/epidemiologia , Estudos Transversais , Doenças Endêmicas/veterinária , Feminino , Humanos , Incidência , Virus da Influenza A Subtipo H5N1 , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , População Urbana , Adulto Jovem
10.
Sci Rep ; 11(1): 19962, 2021 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620890

RESUMO

Live animal markets are known hotspots of zoonotic disease emergence. To mitigate those risks, we need to understand how networks shaped by trading practices influence disease spread. Yet, those practices are rarely recorded in high-risk settings. Through a large cross-sectional study, we assessed the potential impact of live poultry trading networks' structures on avian influenza transmission dynamics in Bangladesh. Networks promoted mixing between chickens sourced from different farming systems and geographical locations, fostering co-circulation of viral strains of diverse origins in markets. Viral transmission models suggested that the observed rise in viral prevalence from farms to markets was unlikely explained by intra-market transmission alone, but substantially influenced by transmission occurring in upstream network nodes. Disease control interventions should therefore alter the entire network structures. However, as networks differed between chicken types and city supplied, standardised interventions are unlikely to be effective, and should be tailored to local structural characteristics.


Assuntos
Comércio , Influenza Aviária/transmissão , Animais , Bangladesh/epidemiologia , Galinhas/virologia , Estudos Transversais , Vírus da Influenza A , Influenza Aviária/epidemiologia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/transmissão
11.
J Nanosci Nanotechnol ; 20(12): 7686-7693, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32711643

RESUMO

The current work reveals notable increase in field emission and photoluminescence characteristics of amorphous carbon nanotubes after forming its composite with In-Situ grown zinc sulfide (ZnS) nanoparticles. An easy chemical technique was employed to synthesize amorphous carbon nanotubes (ACNTs) and then ZnS nanoparticles were grown on them through an In-Situ solvothermal process. The morphology of the ZnS-ACNTs hybrid material was investigated through scanning electron microscope. Photoluminescence and field emission studies of the material were carried out as well in order to realize the applications. Substantial increase in photoluminescence intensity was found for ZnS-ACNTs hybrid material in comparison with pure amorphous carbon nanotubes, the hybrid also turned out as a better field-emitter than pure amorphous carbon nanotubes. Turnon field for ZnS-ACNTs composite decreased to 6 Vµm-1 which was 8 Vµm-1 in case of pure amorphous carbon nanotubes. A simulation analysis following finite element modelling method was carried out which ensured the improvement as field emitter for amorphous carbon nanotubes after ZnS nanoparticles were grown on them. Altogether the hybrid material proved to be a potential candidate for luminescent and cold cathode applications.

12.
Influenza Other Respir Viruses ; 14(3): 349-352, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31912608

RESUMO

In response to unusual crow die-offs from avian influenza A(H5N1) virus infection during January-February 2017 in Dhaka, Bangladesh, a One Health team assessed potential infection risks in live bird markets (LBMs). Evidence of aerosolized avian influenza A viruses was detected in LBMs and in the respiratory tracts of market workers, indicating exposure and potential for infection. This study highlighted the importance of surveillance platforms with a coordinated One Health strategy to investigate and mitigate zoonotic risk.


Assuntos
Aves/virologia , Corvos/virologia , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Influenza Aviária/transmissão , Influenza Humana/transmissão , Doenças das Aves Domésticas/transmissão , Adulto , Animais , Bangladesh/epidemiologia , Galinhas/virologia , Feminino , Humanos , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/epidemiologia , Influenza Aviária/virologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Zoonoses Virais/epidemiologia , Zoonoses Virais/transmissão , Zoonoses Virais/virologia , Adulto Jovem
13.
Sci Rep ; 9(1): 10125, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300669

RESUMO

The formation of the Antarctic Circumpolar Current (ACC) is critical for the evolution of the global climate, but the timing of its onset is not well constrained. Here, we present new seismic evidence of widespread Late Eocene to Oligocene marine diagenetic chert in sedimentary drift deposits east of New Zealand indicating prolonged periods of blooms of siliceous microorganisms starting ~36 million years ago (Ma). These major blooms reflect the initiation of the arrival and upwelling of northern-sourced, nutrient-rich deep equatorial Pacific waters at the high latitudes of the South Pacific. We show that this change in circulation was linked to the initiation of a proto-ACC, which occurred ~6 Ma earlier than the currently estimated onset of the ACC at 30 Ma. We propose that the associated increased primary productivity and carbon burial facilitated atmospheric carbon dioxide reduction contributing to the expansion of Antarctic Ice Sheet at the Eocene-Oligocene Transition.

14.
Nanotechnology ; 30(38): 385204, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31048572

RESUMO

In bulk heterojunction organic solar cells (OSCs), nanomorphology of the photoactive layer plays a crucial role in determining photocurrent and fill factor (FF) of OSCs, and therefore it is essential to control the nanomorphology of the photoactive layer to fabricate devices with high power conversion efficiency (PCE). We demonstrate the combined effects of a ZnO nanorippled electron transport layer (ETL) and solvent additive (1,8-diiodooctane (DIO)) on the nanomorphology and performance of a model OSC in an inverted geometry. The photoactive layer in the model OSC is composed of Poly [4,8-bis (5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl] (PTB7-Th):phenyl-C71-butyric acid methyl ester (PC71BM) blend. It is observed that the use of ZnO nanoripples as an ETL and DIO as a solvent additive facilitates the formation of near ideal nanomorphology of bi-continuous interpenetrating network of donor and acceptor. This is confirmed by morphological studies using atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Photo-electrochemical impedance spectroscopy measurements confirm that obtained nanomorphology of bicontinuous interpenetrating network is contributing to the improved device performance. The device with 3 vol% DIO, with underneath ZnO nanoripples exhibited improved current density (J sc), FF, open circuit voltage (V oc) and PCE of 15.57 mA cm-2, 64.50%, 0.81V and 8.20%, respectively.

15.
Prep Biochem Biotechnol ; 49(7): 704-717, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31017520

RESUMO

Conventional completely mixed anaerobic treatment systems limit the chances of the different species of bacteria to spatially group together according to their mutual cooperation and as a result, show a lower efficiency and vulnerability towards shock situations. It is interesting to know about the stratification of the different bacterial species participating in the degradation process and the intermediates that they produce. In this study, we established and optimized a two-phase anaerobic packed bed biofilm reactor system (AnPBR) with porous PVA gel beads used as bio-carriers and ran the reactor system in a steady state to observe the VFAs produced along with the microbial diversity of the predominant species at different stages of the reactor system. We observed that acetate and butyrate were the predominant intermediate VFAs while concentrations of other VFAs such that propionic acid were low. Acetobacterium and Clostridium were found to be the most abundant bacterial species in acidogenic reactor while methanogenic reactor was highly enriched with Methanobacterium and Methanosarcina. Apart from the above, syntrophic populations such as Syntrophobactor wolinii were also observed to be dominant in both the reactors - especially towards the end of acidogenic reactor and the initial part of the methanogenic reactor.


Assuntos
Bactérias/citologia , Biofilmes , Reatores Biológicos/microbiologia , Ácidos Graxos Voláteis/análise , Géis/química , Álcool de Polivinil/química , Anaerobiose , Bactérias/química , Bactérias/genética , Células Imobilizadas/química , Células Imobilizadas/citologia , Células Imobilizadas/metabolismo , DNA Ribossômico/genética , Desenho de Equipamento , Ácidos Graxos Voláteis/metabolismo , Transição de Fase , Filogenia , Porosidade
16.
Opt Express ; 27(5): 7277-7290, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30876294

RESUMO

In this research work we demonstrated negative axicon optical fiber tip filled with Polydimethylsiloxane (PDMS) as a sensor platform for volatile organic gases detection at room temperature. The response of the sensor was measured with various Volatile Organic Compounds (VOCs) such as Chloroform, Hexane, Isopropanol, Acetone, Toluene and Methanol in the concentration ranging from 5 to 200 ppm. The corresponding sensitivity and limit of detection (LOD) of the developed sensor for the measured VOCs were observed between the order of around 23.7 to 3.2 pm/ppm and 0.84 to 6.10 ppm, respectively. The response and recovery time of sensor were found between the order of 30 to 57 seconds and 8 to 25 seconds respectively for the measured VOCs. Thermal stability of the developed sensor was also studied at 30-70 °C with intervals of 10°C. The principle of sensing is based on change in the length of the Fabry-Perot Interferometric (FPI) cavity in the presence of varied concentrations of VOCs, which results in changes in the shift in wavelength of an interference pattern attributed to the change in PDMS filling the cavity length (swelling). The experimentally observed trends in the relative swelling of PDMS with VOCs are found in agreement with the theoretically calculated values obtained from the Hansen solubility parameter (HSP). The developed gas sensor has the potential to fulfill the demands of industrial applications.

17.
Geohealth ; 3(3): 67-80, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32159032

RESUMO

The northern part of India, adjoining the Himalaya, is considered as one of the global hot spots of pollution because of various natural and anthropogenic factors. Throughout the year, the region is affected by pollution from various sources like dust, biomass burning, industrial and vehicular pollution, and myriad other anthropogenic emissions. These sources affect the air quality and health of millions of people who live in the Indo-Gangetic Plains. The dust storms that occur during the premonsoon months of March-June every year are one of the principal sources of pollution and originate from the source region of Arabian Peninsula and the Thar desert located in north-western India. In the year 2018, month of May, three back-to-back major dust storms occurred that caused massive damage, loss of human lives, and loss to property and had an impact on air quality and human health. In this paper, we combine observations from ground stations, satellites, and radiosonde networks to assess the impact of dust events in the month of May 2018, on meteorological parameters, aerosol properties, and air quality. We observed widespread changes associated with aerosol loadings, humidity, and vertical advection patterns with displacements of major trace and greenhouse gasses. We also notice drastic changes in suspended particulate matter concentrations, all of which can have significant ramifications in terms of human health and changes in weather pattern.

19.
Chemosphere ; 211: 817-825, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30099166

RESUMO

Municipal wastewater treatment plants (WWTP) have been cited as the reservoirs of antibiotic resistance, as they provide suitable conditions for the selection of antibiotic resistant bacteria over the antibiotic-sensitive ones. This study is an attempt to investigate the occurrence of fluoroquinolone (FQ) antibiotics, FQ-resistant bacteria in a WWTP located in India. The results indicated that the concentrations of FQ resistant bacteria ranged from 5.10 × 103 to 5.76 × 103 CFU/mL in the influent stream and 2.66 × 102 to 4 × 102 CFU/mL in the effluent stream. An increase in the fraction of FQ resistant bacteria over the total bacteria is observed at the bio-outlet indicating there is a selection pressure within the biological treatment unit of the treatment plant. The mean concentrations of the FQ antibiotics, namely ciprofloxacin, norfloxacin and ofloxacin in the influent ranged from 6 to 16.4 µg/L with 60-90% of removal in the biological treatment unit. Chlorine-based disinfection process was able to eliminate 96% of the FQ-resistant bacteria from the treated water being discharged into the river Ganges. However, the risk of horizontal gene transformation of resistance was found to be negligible as the resistant mutations occurred at Quinolone resistant determining region (QRDR) of Gyrase A gene. It is observed that 75% of the isolated bacteria showed two point mutations at S83L and D87N positions of the QRDR region of gyrA gene.


Assuntos
DNA Girase/genética , Farmacorresistência Bacteriana/genética , Fluoroquinolonas/química , Águas Residuárias/química , Fluoroquinolonas/análise , Índia
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