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Exposure to elevated particulate matter (PM) concentrations in ambient air has become a major health concern over urban areas worldwide. Reactive oxygen species (ROS) generation due to ambient PM (termed as their oxidative potential, OP) is shown to play a major role in PM-induced health effects. In the present study, the OP of the ambient PM2.5 samples, collected during summer 2019 from New Delhi, were measured using the dithiothreitol (DTT) assay. Average volume-normalized OP (OPV) was 2.9 ± 1.1 nmol DTT min-1 m-3, and mass-normalized OP (OPm) was 61 ± 29 pmol DTT min-1 µg-1. The regression statistics of OPv vs chemical species show the maximum slope of OPV with the elemental carbon (EC, r2 = 0.72) followed by water-soluble organic carbon (WSOC, r2 = 0.72), and organic carbon (OC, r2 = 0.64). A strong positive correlation between OPm and secondary inorganic aerosols (SIA, such as NH4+ and NO3- mass fractions) was also observed, indicating that the sources emitting NO2 and NH3, precursors of NO3- and NH4+, also emit DTT-active species. Interestingly, the slope value of OPv vs OC for aged aerosols (OM/OC > 1.7, f44 > 0.12 and f43 < 0.04) was 1.7 times higher than relatively fresh organic aerosols (OA, OM/OC < 1.7, f44 < 0.12, f43 > 0.04). An increase in OPv and OPoc with f44 indicates the formation of more DTT active species with the ageing of OA. A linear increase in OPoc with increasing Nitrogen/Carbon (N/C) ratio suggests that nitrogenous OA have higher OP.
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BACKGROUND: In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS). METHODS: ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]). RESULTS: Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing. CONCLUSIONS: Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.
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Vazamento de Líquido Cefalorraquidiano , Endoscopia , Procedimentos de Cirurgia Plástica , Base do Crânio , Humanos , Feminino , Masculino , Base do Crânio/cirurgia , Vazamento de Líquido Cefalorraquidiano/etiologia , Vazamento de Líquido Cefalorraquidiano/prevenção & controle , Vazamento de Líquido Cefalorraquidiano/epidemiologia , Estudos Retrospectivos , Pessoa de Meia-Idade , Endoscopia/métodos , Procedimentos de Cirurgia Plástica/métodos , Adulto , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Idoso , Neoplasias Hipofisárias/cirurgia , Neoplasias da Base do Crânio/cirurgia , Rinorreia de Líquido Cefalorraquidiano/prevenção & controle , Rinorreia de Líquido Cefalorraquidiano/cirurgia , Rinorreia de Líquido Cefalorraquidiano/etiologiaRESUMO
In the category of 2D materials, MoS2 a transition metal dichalcogenide, is a novel and intriguing class of materials with interesting physicochemical properties, explored in applications ranging from cutting-edge optoelectronic to the frontiers of biomedical and biotechnology. MoS2 nanostructures an alternative to heavy toxic metals exhibit biocompatibility, low toxicity and high stability, and high binding affinity to biomolecules. MoS2 nanostructures provide a lot of opportunities for the advancement of novel biosensing, nanodrug delivery system, electrochemical detection, bioimaging, and photothermal therapy. Much efforts have been made in recent years to improve their physiochemical properties by developing a better synthesis approach, surface functionalization, and biocompatibility for their safe use in the advancement of biomedical applications. The understanding of parameters involved during the development of nanostructures for their safe utilization in biomedical applications has been discussed. Computational studies are included in this article to understand better the properties of MoS2 and the mechanism involved in their interaction with biomolecules. As a result, we anticipate that this combined experimental and computational studies of MoS2 will inspire the development of nanostructures with smart drug delivery systems, and add value to the understanding of two-dimensional smart nano-carriers.
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Nanoestruturas , Elementos de Transição , Molibdênio/química , Nanoestruturas/química , Sistemas de Liberação de MedicamentosRESUMO
Rice-wheat production in the Indo-gangetic plains (IGPs) of India faces major concerns such as depleting resources, rice residue burning, excessive fertilizer use, and decreasing nitrogen use efficiency. These issues threaten sustainable crop production in the future. Therefore, a field study was conducted during the winter seasons of 2020-21 and 2021-22 to evaluate the effect of combined conventional and nano fertilizers on nitrogen application just before or after irrigation to improve wheat productivity, profitability and NUE under conservation tillage. The study evaluated eight treatment combinations of nitrogen application through conventionally applied urea (46% N) and foliar applied nano urea (4% N) under zero tillage with rice residue retention. Results revealed that growth, physiological indices, yield, and quality parameters were enhanced with the application of 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation alone (T2) or along with a spray of nano urea (T5) compared to other treatments. T5 recorded 7.2%, 8.5%, and 7.8% more plant dry matter, number of tillers, and grain yield, respectively, over the conventional practice of applying 150 kg N/ha in three equal splits as basal and 7-10 days after 1st and 2nd irrigation (T3, farmers practice). Although, T2 showed similar results to T5, T5 recorded significantly higher gross ($2542/ha) and net returns ($1279/ha) than the other treatments. However, the benefit-cost ratio of T2 and T5 was same (2.01). A significant and positive correlation coefficient between grain yield and physiological parameters such as CCI and NDVI confirmed that increasing the nitrogen dose enhanced the chlorophyll content, greenness, and plant vigor. Based on the results, it can be concluded that applying 150 kg N/ha in three equal splits as basal and just before 1st and 2nd irrigation under conservation agriculture, along with a single spray of nano urea (4% N) at 60-65 days after sowing, can improve growth, yield attributes, wheat yield, and NUE compared to farmers practice (T3) in India.
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Oryza , Triticum , Ureia/análise , Agricultura/métodos , Produção Agrícola , Grão Comestível/química , Nitrogênio/análise , Fertilizantes/análise , Solo/químicaRESUMO
Idiopathic Rem sleep Behavior Disorder (iRBD) is a significant biomarker for the development of alpha-synucleinopathies, such as Parkinson's disease (PD) or Dementia with Lewy bodies (DLB). Methods to identify patterns in iRBD patients can help in the prediction of the future conversion to these diseases during the long prodromal phase when symptoms are non-specific. These methods are essential for disease management and clinical trial recruitment. Brain PET scans with 18F-FDG PET radiotracers have recently shown promise, however, the scarcity of longitudinal data and PD/DLB conversion information makes the use of representation learning approaches such as deep convolutional networks not feasible if trained in a supervised manner. In this work, we propose a self-supervised learning strategy to learn features by comparing the brain hemispheres of iRBD non-convertor subjects, which allows for pre-training a convolutional network on a small data regimen. We introduce a loss function called hemisphere dissimilarity loss (HDL), which extends the Barlow Twins loss, that promotes the creation of invariant and non-redundant features for brain hemispheres of the same subject, and the opposite for hemispheres of different subjects. This loss enables the pre-training of a network without any information about the disease, which is then used to generate full brain feature vectors that are fine-tuned to two downstream tasks: follow-up conversion, and the type of conversion (PD or DLB) using baseline 18F-FDG PET. In our results, we find that the HDL outperforms the variational autoencoder with different forms of inputs.
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Indo-Gangetic Plain (IGP) experiences a heavy load of particulate pollution impacting the 9 % of the global population living in this region. The present study examines the dithiothreitol (DTT) assay-based oxidative potential (OP) of PM2.5 and the major sources responsible for the observed OP over the central IGP (Kanpur) during winter. The volume normalized OP (OPV) of PM2.5 varied from 2.7 to 10 nmol DTT min-1 m-3 (5.5 ± 1.5) and mass normalized OP (OPM) of PM2.5 varied from 19 to 58 pmol DTT min-1 µg-1 (34 ± 8.0), respectively. Major sources of PM2.5 were identified using the positive matrix factorization (PMF) and the contribution of these sources to observed OP was estimated through multivariate linear regression of OPv with PMF-resolved factors. Although the PM2.5 mass was dominated by secondary aerosols (SA, 28 %), followed by crustal dust (CD, 24 %), resuspended fine dust (RFD, 14 %), traffic emissions (TE, 8 %), industrial emissions (IE, 17 %), and trash burning (TB, 9 %), their proportionate contribution to OP (except SA) was different likely due to differences in redox properties of chemical species coming from these sources. The SA showed the highest contribution (23 %) to observed OP, followed by RFD (19 %), IE (8 %), TE & TB (5 %), CD (4 %), and others (36 %). Our results highlight the significance of determining the chemical composition of particulates along with their mass concentrations for a better understanding of the relationship between PM and health impacts. Such studies are still lacking in the literature, and these results have direct implications for making better mitigation strategies for healthier air quality.
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It is vital that a straightforward detection approach for trypsin should be developed as it is important diagnostic tool for a number of diseases. Herein, the impact of luminescent MoSe2 quantum dots on trypsin activity under different pH environment has been studied. Addition of trypsin to MoSe2 quantum dots enhanced the fluorescence of quantum dots whereas quantum dots resulted in quenching of fluorescence of trypsin. The quenching behavior at various pH and temperature was examined and revealed that the MoSe2-trypsin complex stabilized through the electrostatic interactions. The obtained negative values of zeta potential of the complex -0.11 mV, -0.30 mV and -0.59 mV for pH 6.0,7.6 and 9.0 respectively confirmed the stability of the complex. The separation between the donor and acceptor atoms in energy transfer mechanism was found to decrease (1.48 nm to 1.44 nm to 1.30 nm) with increasing value of pH. It was also evident that trypsin retained its enzyme activity in the trypsin-MoSe2 complex and under different pH environment. The Vant Hoff plot from quenching revealed 1 binding site for quantum dots by trypsin for all pH of buffer solution. The complex formation of trypsin-MoSe2 quantum dots was verified for the first time using fluorescence spectroscopy and it revealed that tryspin form complex with MoSe2 quantum dots through electrostatic interactions. Our results revealed that the MoSe2 quantum dots stabilized and sheltered the active sites of trypsin, which was likely the cause of the increased bioavailability of MoSe2 quantum dots in enzymes.
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Pontos Quânticos , Pontos Quânticos/química , Tripsina/química , Espectrometria de Fluorescência , Luminescência , Concentração de Íons de Hidrogênio , Transferência Ressonante de Energia de Fluorescência/métodosRESUMO
Phenology, an important ecological attribute, deals with the development of vegetative and reproductive parts of trees called "phenophases", which are important determinants of primary productivity and sensitive to climate change. The present study recorded various phenophases of major tree species (i.e., Quercus leucotrichophora, Rhododendron arboreum, and Myrica esculenta) as per the two-digit numerical system of Biologische Bundesanstalt, Bundessortenamt, Chemische Industrie (BBCH) scale. A total of 72 individual trees, twenty-four from each species, distributed between 1400 and 1980 m. a.s.l elevations were tagged and measured fortnightly for two consecutive years (2019-2021) in the moist temperate forest of Western Himalaya and compared with earlier existing records. Various phenophases were correlated with climatic factors along with duration and thermal time for each phenological growth stage. We found 24 growth stages for Q. leucotrichophora and M. esculenta and 28 for R. arboreum distributed across seven principal growth stages (e.g. bud development, 0; leaf development, 1; shoot development, 3; inflorescence development, 5; flower development, 6; fruit development, 7; and fruit maturation, 8) of trees as per BBCH scale. Maximum growing degree was 748.87 and 627.95 days recorded for R. arboreum and M. esculenta during leaf development, and 796.17 days for Q. leucotrichophora during fruit development. Flower emergence was observed pre, during, and post-emergence of new leaves for R. arboreum, M. esculenta, and Q. leucotrichophora, respectively, which varied at spatial scale with previous findings. Longevity of fruit development to ripening took 17, 4, and 2 months, respectively in Q. leucotrichophora, R. arboreum and M. esculenta. Duration of leaf initiation and flowering was positively correlated with climatic variables, whereas, the reverse was observed for fruiting in the studied tree species. The study concludes that the variations in phenophases of the three species were strongly influenced by climatic variations, especially minimum temperature. The result of the present study would be important in enabling us to formulate efficient forest management strategies by understanding the short-term adaptation of the climate-sensitive important tree species in the western Himalaya.
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The present study assessed the effects of supplementation of different antioxidants on oocyte maturation, embryo production, reactive oxygen species (ROS) production and expression of key developmental genes. In this study, using ovine as an animal model, we tested the hypothesis that antioxidant supplementation enhanced the developmental competence of oocytes. Ovine oocytes aspirated from local abattoir-derived ovaries were subjected to IVM with different concentrations of antioxidants [(Melatonin, Ascorbic acid (Vit C), alpha-tocopherol (Vit E), Sodium selenite (SS)]. Oocytes matured without any antioxidant supplementation were used as controls. The oocytes were assessed for maturation rates and ROS levels. Further, embryo production rates in terms of cleavage, blastocysts and total cell numbers were evaluated after performing in vitro fertilization. Real-Time PCR analysis was used to evaluate the expression of stress related gene (SOD-1), growth related (GDF-9, BMP-15), and apoptosis-related genes (BCL-2 and BAX). We observed that maturation rates were significantly higher in alpha-tocopherol (100 µM; 92.4%) groups followed by melatonin (30 µM; 89.1%) group. However, blastocyst rates in ascorbic acid (100 µM; 19.5%), melatonin (30 µM; 18.4%), alpha-tocopherol (100 µM; 18.2%), and sodium selenite (20 µM; 16.9%) groups were significantly higher (P 0.05) than that observed in the control groups. Total cell numbers in blastocysts in the melatonin, ascorbic acid and alpha-tocopherol groups were significantly higher than those observed in sodium selenite and control groups. ROS production was reduced in groups treated with melatonin (30 µM), vitamin C (100 µM), sodium selenite (20 µM) and α-tocopherol (200 µM) compared with that observed in the control group. Supplementation of antioxidants caused the alterations in mRNA expression of growth, stress, and apoptosis related gene expression in matured oocytes. The results recommend that antioxidants alpha-tocopherol (200 µM), sodium selenite (40 µM), melatonin (30 µM) and ascorbic acid (100 µM) during IVM reduced the oxidative stress by decreasing ROS levels in oocytes, thus improving embryo quantity and quality.
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Antioxidantes , Melatonina , Ovinos , Animais , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Espécies Reativas de Oxigênio/metabolismo , alfa-Tocoferol/farmacologia , alfa-Tocoferol/metabolismo , Melatonina/farmacologia , Melatonina/metabolismo , Selenito de Sódio/farmacologia , Oócitos , Ácido Ascórbico/farmacologia , Blastocisto , Carneiro Doméstico , Expressão Gênica , Suplementos Nutricionais , Técnicas de Maturação in Vitro de Oócitos/veterinária , Técnicas de Maturação in Vitro de Oócitos/métodos , Desenvolvimento EmbrionárioRESUMO
We have developed a non-collective Thomson scattering diagnostic for measurements of electron density and temperature on the Large Plasma Device. A triple grating spectrometer with a tunable notch filter is used to discriminate the faint scattering signal from the stray light. In this paper, we describe the diagnostic and its calibration via Raman scattering and present the first measurements performed with the fully commissioned system. Depending on the discharge conditions, the measured densities and temperatures range from 4.0 × 1012 to 2.8 × 1013 cm-3 and from 1.2 to 6.8 eV, respectively. The variation of the measurement error with plasma parameters and discharges averaged is also discussed.
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The present study evaluated the antibacterial and antibiofilm activity of methanolic extract of Hemidesmus indicus root (MHIR) in combination with amoxicillin and clindamycin against biofilm-forming methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk samples of mastitic cows. Microdilution susceptibility testing and microtitre plate assays were used to evaluate the in vitro efficacy of MHIR and antibiotic combinations against MRSA (n = 12). Furthermore, in vitro findings were validated in a murine model. Minimum inhibitory concentration and minimum biofilm inhibitory concentration of amoxicillin and clindamycin in combination with MHIR were significantly (P < 0·05) lower than when used alone against MRSA. In terms of antibacterial activity, MHIR showed additive interaction (fractional inhibitory concentrationindex >0·5-4) with amoxicillin and clindamycin against all the MRSA isolates, whereas MHIR synergizes (fractional biofilm inhibitory concentrationindex ≤0·5) the antibiofilm activity of amoxicillin and clindamycin against 58·33% and 83·33% of the MRSA isolates respectively. Amoxicillin/clindamycin in combination with MHIR significantly (P < 0·05) reduced disease activity score, and bacterial load and Gram-positive spots in kidney and liver of MRSA-infected mice. The combined efficacy of MHIR and amoxicillin/clindamycin was comparable to clindamycin alone but superior to amoxicillin alone. Hence, the combination of MHIR with amoxicillin/clindamycin is advocated in the treatment of MRSA-associated infections.
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Hemidesmus , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Feminino , Bovinos , Animais , Camundongos , Clindamicina/farmacologia , Amoxicilina/farmacologia , Metanol , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Biofilmes , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/microbiologiaRESUMO
BACKGROUND: Despite multifactorial evidence, the safe and effective elimination of free-floating micro-organisms remains a significant scientific challenge. ZeBox Technology exploits microbial Zeta Potential, to extract and eliminate them from free-flowing air, using a non-ionizing electric field, in combination with a microbicidal surface. AIM: Evaluation of ZeBox Technology against aerosolized SARS-CoV-2 and Mycobacterium tuberculosis under controlled conditions. METHODS: SARS-CoV-2 and M. tuberculosis H37Ra were used in this study. Individual micro-organisms were aerosolized using a Collison nebulizer inside an air-sealed test chamber. Air samples were collected from the chamber on to a Mixed Cellulose Ester membrane, at various time points, and used for enumeration. SARS-CoV-2 was enumerated using qRT-PCR, while M. tuberculosis H37Ra was quantified using standard microbiological procedures. FINDINGS: We established a viable aerosolized microbial load of â¼10E9 and â¼10E6 for SARS-CoV-2 and M. tuberculosis H37Ra, respectively, inside the test chamber. Under ideal conditions, the floating microbial load was at a steady-state level of 10E9 for SARS-CoV-2 and 10E6 for M. tuberculosis. When the ZeBox-Technology-enabled device was operated, the microbial load reduced significantly. A reduction of â¼10E4.7 was observed for M. tuberculosis, while a reduction of â¼10E7 for SARS-CoV-2 was observed within a short duration. The reduction in airborne SARS-CoV-2 load was qualitatively and quantitatively measured using fluorescence analysis and qRT-PCR methods, respectively. CONCLUSION: This validation demonstrates the efficacy of the developed technology against two of the deadliest micro-organisms that claim millions of lives worldwide. In conjunction with the existing reports, the present validation proved the true broad-spectrum elimination capability of ZeBox technology.
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COVID-19 , Mycobacterium tuberculosis , Tuberculose , Humanos , SARS-CoV-2 , Mycobacterium tuberculosis/genética , COVID-19/prevenção & controle , Tuberculose/prevenção & controle , TecnologiaRESUMO
Bakanae disease is an emerging problem for the Basmati rice cultivation in India. Forty-seven endophytes isolated earlier along with three Talaromyces flavus isolates evaluated against Fusaium fujikuroi [Nirenberg] bakanae pathogen [isolate F250] through dual culture and enzymatic assays. Out of 50 isolates, 6 isolates namely, Tf1, Tf2, Tf3, Fusarium equiseti, Fusarium sp. and Trichoderma sp. produced good inhibitory results under in vitro conditions and were proceeded with in planta studies and conducted microscopic studies and real-time PCR assays. Microscopic studies revealed that the defense response system of plants was activated to a longer extent in bioagent treatments, since the number of live nuclei (DAPI staining) and green stained live plant cells (FDA staining) were higher as seen in treated plants when compared to pathogen-inoculated and uninoculated control when observed under confocal laser scanning microscopy. The analysis of cell cycle-related genes expressed during the ROS activity showed increased expression of the cell cycle-related genes involved. The selected isolates were also tested under glasshouse for disease inhibition studies. F. equiseti, Fusarium sp. and Trichoderma sp. gave a disease inhibition of, 87%, 66% and 94%, respectively. Tf2 and Tf1 isolate dominantly inhibited the disease with 95% whereas Tf3 also inhibited successfully with 70%. Through the results of our study, we can deduce that the T. flavus (Tf1, Tf2, Tf3) isolates and the endophytes F. equiseti, Fusarium sp. and Trichoderma sp. may represent an important biocontrol agent to control the bakanae disease of rice and also implicated that could further be befitting to capitalize them for field evaluations.
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Fusarium , Oryza , Trichoderma , Índia , Oryza/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Trichoderma/genéticaRESUMO
OBJECTIVE: Here, Bronco T (BT), a polyherbal formulation developed in 1984 for treating asthma, has been repurposed against septicemia-induced ALI. MATERIALS AND METHODS: Lipopolysaccharides (3 mg/kg BW) were injected intraperitoneally before 24 hours of surgery to assess the cardiorespiratory parameters, blood PaO2/FiO2 and MPO, pulmonary water content and histological changes in the lungs. The pentoxifylline (PTX) (25 mg/kg BW) was used as the positive control and given one hour before LPS. BT was given 3 hours (orally at different doses of 3, 1.5 and 0.75 g/kg BW) before LPS. RESULTS: The LPS treated group showed significant bradypnea, hypotension and bradycardia, through elongated peaks (RR) and (MAP) respectively and finally death after 95 minutes of LPS injection. The PTX and BT (3 g/kg BW) pretreatment significantly prevented these changes (dose-dependent in the BT group). The survival in these groups was maintained up to 190 min after LPS. The Pentoxifylline showed a better response (75%) than Bronco T (72%). In both the treatments, a significant decrease in pulmonary water content and minimal neutrophil infiltration and intact alveoli-capillary membrane was seen in the transverse section (T.S) of the lungs. CONCLUSIONS: Significant improvement was noted in survival time with lesser tissue damage and improved pulmonary function was observed by pre-treating with Bronco T in LPS induced septicemia.
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Lesão Pulmonar Aguda , Pentoxifilina , Sepse , Lesão Pulmonar Aguda/patologia , Animais , Lipopolissacarídeos/efeitos adversos , Pulmão/patologia , Pentoxifilina/farmacologia , Ratos , Sepse/induzido quimicamente , Sepse/tratamento farmacológico , Sepse/patologia , ÁguaRESUMO
Abstract: Rice-wheat cropping system, intensively followed in Indo-Gangetic plains (IGP), played a prominent role in fulfilling the food grains demand of the increasing population of South Asia. In northern Indian plains, some practices such as intensive rice cultivation with traditional method for long-term have been associated with severe deterioration of natural resources, declining factor productivity, multiple nutrients deficiencies, depleting groundwater, labour scarcity and higher cost of cultivation, putting the agricultural sustainability in question. Varietal development, soil and water management, and adoption of resource conservation technologies in rice cultivation are the key interventions areas to address these challenges. The cultivation of lesser water requiring crops, replacing rice in light-textured soil and rainfed condition, should be encouraged through policy interventions. Direct seeding of short duration, high-yielding and stress tolerant rice varieties with water conservation technologies can be a successful approach to improve the input use efficiency in rice cultivation under medium-heavy-textured soils. Moreover, integrated approach of suitable cultivars for conservation agriculture, mechanized transplanting on zero-tilled/unpuddled field and need-based application of water, fertilizer and chemicals might be a successful approach for sustainable rice production system in the current scenario. In this review study, various challenges in productivity and sustainability of rice cultivation system and possible alternatives and solutions to overcome such challenges are discussed in details.
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Aerosols emitted in densely populated and industrialized Indo-Gangetic Plain, one of the most polluted regions in the world, modulate regional climate, monsoon, and Himalayan glacier retreat. Thus, this region is important for understanding aerosol perturbations and their resulting impacts on atmospheric changes during COVID-19 lockdown period, a natural experimental condition created by the pandemic. By analyzing 5 years (2016-2020) data of aerosols and performing a radiative transfer calculation, we found that columnar and near-surface aerosol loadings decreased, leading to reductions in radiative cooling at the surface and top of the atmosphere and atmospheric warming during lockdown period. Further, satellite data analyses showed increases in cloud optical thickness and cloud-particle effective radius and decrease in lower tropospheric air temperature during lockdown period. These results indicate critical influences of COVID-19 lockdown on regional climate and water cycle over Indo-Gangetic Plain, emphasizing need for further studies from modeling perspectives.
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The intercropping of legumes with cereals help to achieve sustainable intensification by their mutual complementarity at efficiently using radiation, nutrients, etc. Several studies indicated such beneficial effects on the other component crop however, little research has been conducted to quantify their effects on the subsequent crop in a cropping system. In this study, the effect of the legume intercropping on the entire cropping system, particularly the maize + legume-wheat system was studied. Four legumes intercropped to maize followed by wheat crop were studied for intensification measures such as wheat equivalent yield (WEY), land equivalent ratio (LER), sustainable value index (SVI), and economic returns. N saving effect of legumes on the subsequent wheat crop was quantified with two N levels. Maize + cowpea-wheat combination was the most productive and economic intercrop combination (LER = 1.71, SVI = 0.96) with an increase in net economic return (43.63%) with a B:C ratio of 1.94. An additional 25% N (37.5 kg ha-1) was saved in the wheat crop when the legume intercropping was undertaken with maize. The results suggest that intercropping is the key to diversification and reduces the risk of crop failures by enhancing land-use efficiency, soil fertility, and economic returns under weather vagaries. This will be beneficial to small and marginal farmers of many countries.
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Microbial fuel cells (MFC) are a novel technique for power generation from wastewater. A number of approaches for the modification of physical as well as chemical properties of the electrodes can be employed to attain the maximum output power density and high power electricity. The use of an active organic linker, extracted from waste residue (plastic), for the synthesis of porous nanostructured materials would be beneficial in the fabrication of electrodes for MFC. Herein, terephthalic acid monomer (t) derived from plastic waste was successfully applied as an electrochemically active linking unit to form an iron-based metal-organic framework (Fe-t-MOF: MIL-53(Fe)). The synthesized Fe-t-MOF was further modified with conducting polymer (polyaniline (PANI)). The produced nanocomposite (Fe-t-MOF/PANI) was coated on stainless steel (SS) disk (as a current collector) for use as an electrode component of the MFC system. The power density, open circuit potential (OCP), and a limiting current density of the MFC are 680 mW/m2, 0.67 V, and 3500mA/m2, respectively. The technique opted here should help search a novel, efficient, sustainable, and cost-effective route for the modification of the plastic waste into an MFC electrode to achieve bioenergy production through wastewater treatment.
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Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Plásticos , Águas ResiduáriasRESUMO
Cesium compounds if present in atmosphere, can affect human health as well as the ecosystem due to their highly hazardous nature. Interaction of cesium compounds with abundantly available atmospheric salts can modify the hygroscopic behavior in sub-saturation relative humidity (RH) domain. Any marked modification in growth factor (GF) for the mixed particle state in comparison to the single particles ultimately affects the settling rates and hence the deposition flux. This work studies the hygroscopic behavior of two important cesium bound fission product aerosols (CsI, CsOH) internally mixed with some common atmospheric particles viz. [Formula: see text] and NaNO3 for a fixed dry particle size of 100 nm. Experimental measurements, performed with Hygroscopic tandem differential mobility analyzer in the range of 20-94% RH, have been compared with the predictions made from Zdanovskii-Stokes-Robinson (ZSR) approach. Apart from the single/pure particle state for the constituents (i.e. mixing ratios 1:0 and 0:1), three other mixing ratios 1:4, 1:1 and 4:1 have been considered. The results show that the GF vs RH pattern for mixed particles is different from that for single CsI and CsOH particles. The intrinsic water uptake behavior for these cesium compounds was found to be perturbed for some of the chosen combinations as well. Deliquescent transition for the mixed particles was observed at lower RH compared to the single electrolytes. Relative differences noticeable for the chosen mixing ratios could be related to the available fractions in the mixed state. Overall, ZSR method was found to be capturing the trend of increasing GFs with increasing RH. Terminal gravitational settling velocities calculated from the measured GFs were also found to be different for single and mixed particles. The relative difference was significant for some combinations and test conditions. Any modification in settling velocity ultimately impacts the deposition flux estimations. Hence neglecting the presence of atmospheric salts affects the accuracy of the source term estimates for a postulated nuclear reactor accident scenario.
Assuntos
Atmosfera , Ecossistema , Aerossóis , Césio , Humanos , MolhabilidadeRESUMO
It is well established that light-absorbing organic aerosols (commonly known as brown carbon, BrC) impact climate. However, uncertainties remain as their contributions to absorption at different wavelengths are often ignored in climate models. Further, BrC exhibits differences in absorption at different wavelengths due to the variable composition including varying sources and meteorological conditions. However, diurnal variability in the spectral characteristics of water-soluble BrC (hereafter BrC) is not yet reported. This study presents unique measurement hitherto lacking in the literature. Online measurements of BrC were performed using an assembled system including a particle-into-liquid sampler, portable UV-Visible spectrophotometer with liquid waveguid capillary cell, and total carbon analyzer (PILS-LWCC-TOC). This system measured the absorption of ambient aerosol extracts at the wavelengths ranging from 300 to 600 nm with 2 min integration time and water-soluble organic carbon (WSOC) with 4 min integration time over a polluted megacity, New Delhi. Black carbon, carbon monoxide (CO), nitrogen oxides (NOx), and the chemical composition of non-refractory submicron aerosols were also measured in parallel. Diurnal variability in absorption coefficient (0.05 to 65 Mm-1), mass absorption efficiency (0.01 to 3.4 m-2 gC-1) at 365 nm, and absorption angstrom exponent (AAE) of BrC for different wavelength range (AAE300-400: 4.2-5.8; AAE400-600: 5.5-8.0; and AAE300-600: 5.3-7.3) is discussed. BrC chromophores absorbing at any wavelength showed minimum absorption during afternoon hours, suggesting the effects of boundary layer expansion and their photo-sensitive/volatile nature. On certain days, a considerable presence of BrC absorbing at 490 nm was observed during nighttime that disappears during the daytime. It appeared to be associated with secondary BrC. Observations also infer that BrC species emitted from the biomass and coal burning are more absorbing among all sources. A fraction of BrC is likely associated with trash burning, as inferred from the spectral characteristics of Factor-3 from the PMF analysis of BrC spectra. Such studies are essential in understanding the BrC characteristics and their further utilization in climate models.