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1.
Nano Lett ; 24(18): 5395-5402, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38684070

RESUMO

We investigated the role of ligand clustering and density in the activation of natural killer (NK) cells. To that end, we designed reductionist arrays of nanopatterned ligands arranged with different cluster geometries and densities and probed their effects on NK cell activation. We used these arrays as an artificial microenvironment for the stimulation of NK cells and studied the effect of the array geometry on the NK cell immune response. We found that ligand density significantly regulated NK cell activation while ligand clustering had an impact only at a specific density threshold. We also rationalized these findings by introducing a theoretical membrane fluctuation model that considers biomechanical feedback between ligand-receptor bonds and the cell membrane. These findings provide important insight into NK cell mechanobiology, which is fundamentally important and essential for designing immunotherapeutic strategies targeting cancer.


Assuntos
Membrana Celular , Células Matadoras Naturais , Células Matadoras Naturais/imunologia , Membrana Celular/química , Membrana Celular/metabolismo , Humanos , Ligantes , Ativação Linfocitária , Fenômenos Biomecânicos , Modelos Biológicos
2.
Environ Monit Assess ; 196(7): 608, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38861164

RESUMO

Satellite-based precipitation estimates are a critical source of information for understanding and predicting hydrological processes at regional or global scales. Given the potential variability in the accuracy and reliability of these estimates, comprehensive performance assessments are essential before their application in specific hydrological contexts. In this study, six satellite-based precipitation products (SPPs), namely, CHIRPS, CMORPH, GSMaP, IMERG, MSWEP, and PERSIANN, were evaluated for their utility in hydrological modeling, specifically in simulating streamflow using the Variable Infiltration Capacity (VIC) model. The performance of the VIC model under varying flow conditions and timescales was assessed using statistical indicators, viz., R2, KGE, PBias, RMSE, and RSR. The findings of the study demonstrate the effectiveness of VIC model in simulating hydrological components and its applicability in evaluating the accuracy and reliability of SPPs. The SPPs were shown to be valuable for streamflow simulation at monthly and daily timescales, as confirmed by various performance measures. Moreover, the performance of SPPs for simulating extreme flow events (streamflow above 75%, 90%, and 95%) using the VIC model was assessed and a significant decrease in the performance was observed for high-flow events. Comparative analysis revealed the superiority of IMERG and CMORPH for streamflow simulation at daily timescale and high-flow conditions. In contrast, the performances of CHIRPS and PERSIANN were found to be poor. This study highlights the importance of thoroughly assessing the SPPs in modeling diverse flow conditions.


Assuntos
Monitoramento Ambiental , Hidrologia , Chuva , Rios , Índia , Rios/química , Monitoramento Ambiental/métodos , Modelos Teóricos , Movimentos da Água , Imagens de Satélites , Clima Tropical
3.
Environ Monit Assess ; 196(2): 111, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38175297

RESUMO

The agricultural sector in India primarily relies on monsoon rains, making it necessary for agricultural water managers to study variations in water availability by analyzing rainfall patterns. This information is critical for deciding cropping patterns and irrigation approaches, managing water resources, and improving crop water productivity. The long-term spatiotemporal variability over the command area, India Meteorological Department (IMD) based selection of thresholds for extremes indices, and thorough analysis of the consequences of extreme on agriculture make the study unique. These aspects collectively enhance the perception of the climate-agriculture relationship, which is essential for promoting agriculture resilience under changing rainfall patterns. This type of research is very limited in the literature. Therefore, the present study focuses on comprehensively analyzing the spatiotemporal variability of rainfall and extreme precipitation indices and their implications on agriculture. The study is carried out in the Upper Ganga Command Area (UGCA), India's oldest irrigation canal system, by using long-term (1901-2021) high-resolution (0.25 × 0.25°) daily rainfall gridded data obtained from IMD, Pune. Eight different extreme rainfall indices are used to assess spatiotemporal variations. The Mann-Whitney-Pettitt test identified 1970 as a significant change point. Rainfall trends and extreme indices for pre- and post-1970 periods were examined using the non-parametric modified Mann-Kendall test. The results show significant increases in rainfall trends for the annual, monsoon, and kharif seasons from 1901 to 1970, but significant decreases were observed during 1971-2021. This difference resulted in a noticeable decrease in average precipitation in the latter period, approximately 62 mm less than in 1901-1970. Similarly, extreme precipitation indices, including the number of rainy days (NxRainy), consecutive dry days (CWD), simple daily intensity index (SDII), and total precipitation (PRCPTOT), exhibited increasing trends in 1901-1970, but they showed significant decreasing trends in 1971-2021. In addition, there is a strong positive correlation between these indices and total precipitation. The study also found that geographical factors influence these trends, with all indices, except SDII, strongly correlated with latitude and elevation, but not with longitude. The implications of these negative rainfall and extreme rainfall trends were further analyzed, and the results indicate a significant impact on the cropping patterns in the study area. The present research findings will be beneficial for regional water resource managers and policymakers in better understanding the existing trends in rainfall distribution over the UGCA.


Assuntos
Agricultura , Monitoramento Ambiental , Índia , Produção Agrícola , Água
4.
Environ Res ; 237(Pt 1): 116859, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37562739

RESUMO

The characterization of a rainfall simulator provides an excellent opportunity to study the potential of soil erosivity without waiting for natural rain. But, precise instrumentation is required to estimate the parameters, which is seldom available. To overcome this problem, the empirical and conceptual relationships obtained through physically-based modeling help to correlate the rain parameters contributing to soil erosion. The present laboratory study used five pressurized nozzles of different capacities and a Laser Precipitation Monitor (LPM) to generate different rain intensities (21.0-79.0 mm h-1) and to register drop size distribution, respectively. The sediment transportation induced by rain and runoff was measured with an erosion flume of 2.50 × 1.25 × 0.56 m with an adjustable longitudinal slope. The spatial uniformity, drop size distribution, drop velocity, and kinetic energy were used to evaluate the simulator's performance. The different rain erosivity parameters were correlated and tested statistically using linear and non-linear regression analysis. The rain simulation experiments of different intensities at different pressure ranges were performed on flat, 5, 10, and 15% slopes of the erosion flume to evaluate rain characteristics and record the surface runoff and sediment yield. The median drop sizes produced during the simulator ranged from 0.38 to 2.11 mm, coinciding with natural rain. The empirical relationships were developed to correlate surface discharge and sediment yield with rain intensity by optimizing the parameters for further study of experimental field plots of different slopes. The observed and estimated rain erosivity parameters showed a significant relationship (R2 = 0.75 to 0.93; P < 0.001) in multiple regression analysis, and the metrics used to test the developed regression equations showed lower MAE, MSE, and RMSE errors indicating the adequacy of the relationships. The results indicated that the simulator helps to understand the complex task of soil erosion with hydrologic and geomorphic processes in laboratory experimentation with sufficient accuracy in measuring sediment transport events.

5.
Environ Monit Assess ; 195(9): 1118, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37648891

RESUMO

The high mountain ecosystem of the Indian Himalayas has frequently been experiencing primary hazards (like earthquakes, avalanches, and landslides). Often, these events are followed by the triggering of secondary hazards (like landslide dams, debris flows, and flooding), thereby posing massive risks to infrastructure and residents in the region. This study was taken up to understand the dynamics of an extraordinary debris flood disaster in the Rishiganga River valley, Chamoli district of Uttarakhand on 7th February 2021. Rapid mass movements (RAMMS)-debris flow software was employed to recreate the entire sequence of the hazard consisting of a rock-ice slide, mass deposition and erosion along the channel, and subsequent debris flood. Forty-nine scenarios were analyzed for accurate calibration of dry-Coulomb type friction coefficient (µ) and viscous-turbulent friction coefficient (ξ). Consequently, the geomorphologic characteristics of the debris flow were validated using high-resolution satellite image interpretation and field photographs. The volume of detached rock-ice mass was estimated to be 26.42 × 106 m3. At the same time, the RAMMS-derived model outputs for velocity, flow depth, and momentum were found in good agreement with the extent and height of actual debris on the ground. The study highlights an urgent need to identify the glaciers with a high risk of ice avalanches in the Indian Himalayas. The presented modeling approach may be applied in dynamic mountain ecosystems to simulate potential flash floods due to avalanches. Moreover, the information reported in this study can be vital input for improving the district-level disaster management plan.


Assuntos
Avalanche , Inundações , Ecossistema , Rios , Monitoramento Ambiental , Camada de Gelo
6.
J Environ Manage ; 319: 115675, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35834856

RESUMO

Increasing demand of pure and accessible water and improper disposal of waste into the existing water resources are the major challenges for sustainable development. Nanoscale technology is an effective approach that is increasingly being applied to water remediation. Compared to conventional water treatment processes, silver nanotechnology has been demonstrated to have advantages due to its anti-microbial and oligodynamic (biocidal) properties. This review is focused on environmentally friendly green syntheses of silver nanoparticles (AgNPs) and their applications for the disinfection and microbial control of wastewater. A bibliometric keyword analysis is conducted to unveil important keywords and topics in the utilisation of AgNPs for water treatment applications. The effectiveness of AgNPs, as both free nanoparticles (NPs) or as supported NPs (nanocomposites), to deal with noxious pollutants like complex dyes, heavy metals as well as emerging pollutants of concern is also discussed. This knowledge dataset will be helpful for researchers to identify and utilise the distinctive features of AgNPs and will hopefully stimulate the development of novel solutions to improve wastewater treatment. This review will also help researchers to prepare effective water management strategies using nano silver-based systems manufactured using green chemistry.


Assuntos
Poluentes Ambientais , Nanopartículas Metálicas , Purificação da Água , Química Verde , Nanopartículas Metálicas/química , Nanotecnologia , Prata
7.
Environ Monit Assess ; 194(12): 883, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36239815

RESUMO

Drought is considered among the most perilous events with catastrophic consequences, particularly from the agro-economic point of view. These consequences are expected to exacerbate under the increasing meteorological aberrations due to changing climate, which necessitates investigating drought variabilities. This study presents a thorough spatiotemporal assessment of drought trends and variabilities over the agriculture-dominated Marathwada Region, Maharashtra, India. The precipitation data is extracted from the India Meteorological Department (IMD) gridded product, whereas actual evapotranspiration (ET) and Evaporative Stress Index (ESI) are obtained from Global Land Evaporation Amsterdam Model (GLEAM) datasets. Standardized Precipitation Index (SPI) is used to characterize drought occurrences at multiple time frames, whereas non-parametric tests, i.e., modified Mann-Kendall (MMK) and Sen's slope (SS) tests, are employed to detect trends. The results reveal the region to be prone to droughts, and SPI at a longer time frame (i.e., 12-monthly moving frame) can capture drought occurrences better than the shorter time frames, which can be attributed to the lesser randomness in the time series in the longer frame. A mix of positive/negative trends of SPI series are found for the monsoonal months; however, they are relatively more concentrated towards negative ZMMK. Hence, the Marathwada Region can be inferred to have exhibited a relatively increased tendency towards drought occurrences. The seasonal differences in mean values and trends of rainfall, ET, and ESI are discussed in detail. Since the Marathwada Region has a monsoon-dominated climate with high agricultural importance, the information reported in this study will help in devising water management strategies to minimize the repercussions of droughts.


Assuntos
Secas , Monitoramento Ambiental , Agricultura , Índia , Meteorologia
8.
Environ Monit Assess ; 194(12): 893, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36242650

RESUMO

In this study, the long-term trends in climatological parameters, viz., maximum temperature (TMAX) and minimum temperature (TMIN), are determined over 68 years (i.e., June 1951 to May 2019) using the gridded observation datasets (1° × 1° spatial resolution) of India Meteorological Department over the Narmada river basin, India. Multiple non-parametric techniques, viz., modified Mann-Kendall (MMK), Sen's slope (SS), and Spearman's rho (SR) tests, are used to determine monthly, seasonal, and annual trends over individual grids. The trends are also analyzed for the climatic variables spatially averaged over the entire basin to draw general conclusions on historical climate change. The results reveal a significant spatiotemporal variation in trends of TMAX and TMIN over the basin. In general, both the parameters are found to be increasing. Furthermore, the hottest months (April and May) have become hotter, and the coldest month (January) has become colder, implying a higher probability of increasing temperature extremes. Furthermore, the entire duration of 68 years is divided into two epochs of 34 years, i.e., 1951-1984 and 1985-2018, and the trend analysis of TMAX and TMIN is also carried out epoch-wise to better understand/assess the signals of climate change in recent years. In general, a relatively higher warming trend was observed in the latter epoch. As a majority of the basin area is dominated by agricultural lands, the implications of the temperature trends and their impacts on agriculture are succinctly discussed. The information reported in this study will be helpful for proper planning and management of water resources over the basin under the changing climatic conditions.


Assuntos
Monitoramento Ambiental , Rios , Agricultura , Mudança Climática , Temperatura
9.
Med J Armed Forces India ; 78(Suppl 1): S312-S314, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36147394

RESUMO

Infectious scleritis is rare and most commonly herpetic in origin. We report an unusual bilateral subacute presentation of scleritis with uveitis and glaucoma which responded to treatment with acyclovir. A 47-year-old male coast guard personnel presented with 2 months history of bilateral red eye. He was initially managed elsewhere as conjunctivitis, and on examination had bilateral diffuse redness of the eyes persisting with phenylephrine, with scleral edema and mild globe tenderness. Investigations for underlying autoimmune systemic illness were normal. He showed inadequate response to topical steroids and cycloplegics and developed uveitis and glaucoma while on steroids. He was then given tablet acyclovir with antiglaucoma topical medications with which he showed rapid response and complete resolution. The case is being reported for highlighting this unusual bilateral presentation of scleritis with uveitis and glaucoma with possible viral etiology.

10.
J Environ Manage ; 296: 113154, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34216905

RESUMO

The large generation of electronic waste (e-waste) is posing a serious threat to society. It is important to develop sustainable technology for the effective management of e-waste and the recovery of valuable metals from it. The present study employed hydrometallurgical approach for Cu and Ni extraction from waste printed circuit boards (WPCB) of mobile phones. This study demonstrates the application of ammonia-ammonium sulfate leaching for the maximum recovery of Cu and Ni. Investigations revealed that the most favourable reaction parameters for efficient metal extraction are - ammonia concentration - 90 g/L, ammonium sulfate concentration - 180 g/L, H2O2 concentration - 0.4 M, time - 4 h, liquid to solid ratio - 20 mL/g, temperature - 80 °C and agitation speed - 700 rpm. Under these conditions, 100% Cu and 90% Ni were extracted. Furthermore, the kinetic study was performed using the shrinking core model which revealed that the internal diffusion is the rate-controlling step for Cu and Ni extraction. The activation energies for Cu and Ni extraction were found out to be 4.5 and 5.7 kJ/mol, respectively. Finally, Cu was recovered with 98.38% purity using electrowinning at a constant DC voltage of 2.0 V at Al cathode. The present study provides a solution for concurrent extraction of Cu and Ni from the raw WPCB of mobile phones and selective recovery of Cu from metal leached solution. The process has the potential to recover the resources from WPCB while minimising the pollution caused by mismanagement of WPCB.


Assuntos
Álcalis , Resíduo Eletrônico , Amônia , Cobre , Resíduo Eletrônico/análise , Peróxido de Hidrogênio , Metais , Reciclagem
11.
Soft Matter ; 15(13): 2897-2904, 2019 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-30849161

RESUMO

Nanoimprinting with rigid molds offers almost unlimited pattern resolution, but it suffers from high sensitivity to defects, and is limited to pattering flat surfaces. These limitations can be addressed by nanoimprinting with soft molds. However, soft molds have been used so far with UV resists, and could not achieve a resolution and minimal feature size comparable to those of rigid molds. Here, we explore the miniaturization edge of soft nanoimprint molds, and demonstrate their compatibility with thermal imprint resists. To that end, we produced a pattern with 10 nm critical dimensions, using electron beam lithography, and used it to replicate nanoimprint molds by direct casting of an elastomer onto the patterned resist. We showed that the produced pattern can be faithfully transferred from the mold by thermal nanoimprinting. In addition, we showed that similar nanoimprint molds can also be produced by double replication, which includes nanoimprinting of a thermal resist with an ultrahigh resolution rigid mold, and replication of a soft mold from the imprint pattern. We also demonstrated our novel nanoimprinting approach in two unconventional applications: nanopatterning of a thermal resist on a lens surface, and direct nanoimprinting of chalcogenide glass. Our novel nanoimprint approach pushes the envelope of standard nanofabrication, and demonstrates its potential for numerous applications impossible up to now.

12.
J Contemp Dent Pract ; 20(1): 51-55, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31102395

RESUMO

AIM: Osteoporosis is one of the diseases which show significant bone mass reduction especially in post menopausal women. The present study was conducted to determine the effect of Bisphosphonates (BP) on alveolar bone and dental implant therapy in women after menopause. MATERIALS AND METHODS: The present study was conducted on 30 postmenopausal women who received at least one dental implant in the last 5 years. Group I comprised of 15 patients who were on BP therapy for 1.5 years, and group II consisted of 15 patients who were on parathyroid hormone (PTH). Bone mineral density (BMD) and bone thickness were assessed in both groups. RESULTS: Group I had 3.85% and group II had 3.15% of dental implants failures. BMD of cortical bone was 1552± 145 mg/mL and 1012 ± 94 mg/mL in groups I and II respectively. BMD of cancellous bone was 80 ± 15 mg/mL and 104 ± 72 mg/mL in group I and group II respectively. The difference was significant (p < 0.05). Cortical bone thickness was 2.5 ± 0.6 mm in group I and 2.2 ± 0.8 mm in group II. The difference was non-significant (p >0.05). There was a reduction in BMD (mg/mL) of cortical and cancellous bone. There was an increase in cortical bone thickness with the use of BPs over the years. The difference was significant (p < 0.05). CONCLUSION: There was a decrease in bone mineral density of both cortical and cancellous bone in both groups. There was increase cortical bone thickness on prolonging use of BPs. CLINICAL SIGNIFICANCE: Patients on BPs therapy should be carefully evaluated both clinically and radiographically before dental implant treatment as these agents affect the quantity and quality of cortical bone especially in the posterior mandibular region in patients with osteoporosis.


Assuntos
Implantes Dentários , Densidade Óssea , Tomografia Computadorizada de Feixe Cônico , Difosfonatos , Feminino , Humanos , Pós-Menopausa
14.
Indian J Public Health ; 61(Suppl 1): S60-S62, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28928321

RESUMO

Endgame strategies to rapidly hasten the decline of tobacco are already well within reach; a few plausible policy options are outlined herein for policy practitioners, tobacco control advocates, and public health specialists. The implementation of these measures which already exist within the gamut of existing legislation requires the galvanization of political will. The options we essay include liquidating existing public investments in tobacco, holding tobacco companies accountable within the jurisdictions of their operations, fixing liability for injury and the imposition of realistic costs on insurance providers.


Assuntos
Política de Saúde , Formulação de Políticas , Abandono do Hábito de Fumar , Humanos , Índia , Seguro Saúde/economia , Responsabilidade Legal , Indústria do Tabaco
15.
Phys Chem Chem Phys ; 16(4): 1559-68, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24305780

RESUMO

Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1 : 2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in vibronic bands, indicates reline, the DES composed of urea as the hydrogen bond donor, to be significantly more dipolar than the other three DESs. Response of pyrene-1-carboxaldehyde, a polarity probe based on inversion of n-π* and π-π* states, hints at maline to be the most dipolar of the four DESs. The molecular structure of the H-bond donor in a DES clearly controls the dipolarity afforded by the DES. H-bonding and other specific solute-solvent interactions are found to play an important role in solvatochromic probe behavior for the four DESs. The cybotactic region of a probe dissolved in a DES affords information on the polarity of the DES towards solutes of similar nature and functionality.

16.
Biol Trace Elem Res ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862749

RESUMO

Reconceptualizing cancer immunotherapy can be improved if combined with plant production systems and nanotechnology. This review aims to contribute to the knowledge of plant use in nanomedicine and cancer immunotherapy. In the foreground, we outlined each of these approaches; nanomedicine, green synthesis, and immunotherapy. The benefits of plant-based nanoparticles in mending the immune systems were subsequently analyzed, with reference to the literature. The combining effects of biological and therapeutic properties of some phytochemicals and their derivatives, with targeted nanoparticles and selective immunotherapy, can enhance the delivery of drugs and antibodies, and induce antitumor immune responses, via activation of functions of neutrophils, lymphocyte cells, and natural killer cells, and macrophages, resulting in induced apoptosis and phagocytosis of tumor cells, which can improve designing immunotherapeutic strategies targeting cancer, with a larger spectrum compared to the current cytotoxic anticancer drugs commonly used in clinics. This study uncovers the mechanistic drivers of cancer immunoengineering in cancer therapy using plant-based nanomaterials, enhancing therapeutic benefits while minimizing toxic and side effects.

17.
Indian J Ophthalmol ; 72(7): 1031-1036, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38905463

RESUMO

PURPOSE: To investigate the influence of digital device use (computers, laptops, tablets, smartphones) on dry eye disease (DED) in a pediatric population. SETTINGS AND DESIGN: This was a cross-sectional study. School children studying in grades 5-9 at two private schools in the city of Ahmedabad, the capital city of Gujarat, India were invited to participate in the study. METHODS: In this study, 462 children underwent ocular examination including tear film breakup time (TBUT) and Schirmer's test. Questionnaires were administered for collecting information on the type and duration of digital device usage separately for academic and leisure activities and the Ocular Surface Disease Index (OSDI) score. RESULTS: The mean age of participants was 11.2 + 1.4 years, and 63% were boys. The mean OSDI score was 37.2 + 11.8, and 90.5% had symptoms of DED. Children with moderate to severe DED (n = 88, 19%) had longer daily duration of device use and lower Schirmer's test and TBUT values compared to children with mild DED (P = 0.001). A cumulative exposure time of more than 3-3.5 h per day had a significantly increased risk of DED. Multivariable logistic regression analysis showed that increment in computer usage (odds ratio [OR] 1.94 for every half an hour increase, 95% confidence interval [CI] = 1.2-3.1) and children studying in higher grades (OR 1.30, 95% CI = 1.1-1.6) had a higher risk of moderate to severe dry eye. CONCLUSION: Cumulative device exposure time of more than 3-3.5 h per day had a significantly increased risk of pediatric DED. Children with an increment in computer usage by half an hour per day had a higher chance of experiencing moderate to severe dry eye. Policymakers should aim to restrict the screen time below 3 h on a daily basis.


Assuntos
Síndromes do Olho Seco , Lágrimas , Humanos , Síndromes do Olho Seco/epidemiologia , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/etiologia , Masculino , Feminino , Criança , Estudos Transversais , Índia/epidemiologia , Inquéritos e Questionários , Adolescente , Instituições Acadêmicas , Computadores/estatística & dados numéricos , Smartphone , Incidência , Computadores de Mão , Fatores de Risco
18.
Adv Mater ; 36(21): e2309284, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38340044

RESUMO

Nanoscale organization of transmembrane receptors is critical for cellular functions, enabled by the nanoscale engineering of bioligand presentation. Previously, a spatial threshold of ≤60 nm for integrin binding ligands in cell-matrix adhesion is demonstrated using monoliganded gold nanoparticles. However, the ligand geometric arrangement is limited to hexagonal arrays of monoligands, while plasmonic quenching limits further investigation by fluorescence-based high-resolution imaging. Here, these limitations are overcome with dielectric TiO2 nanopatterns, eliminating fluorescence quenching, thus enabling super-resolution fluorescence microscopy on nanopatterns. By dual-color super-resolution imaging, high precision and consistency among nanopatterns, bioligands, and integrin nanoclusters are observed, validating the high quality and integrity of both nanopattern functionalization and passivation. By screening TiO2 nanodiscs with various diameters, an increase in fibroblast cell adhesion, spreading area, and Yes-associated protein (YAP) nuclear localization on 100 nm diameter compared with smaller diameters was observed. Focal adhesion kinase is identified as the regulatory signal. These findings explore the optimal ligand presentation when the minimal requirements are sufficiently fulfilled in the heterogenous extracellular matrix network of isolated binding regions with abundant ligands. Integration of high-fidelity nano-biopatterning with super-resolution imaging allows precise quantitative studies to address early signaling events in response to receptor clustering and their nanoscale organization.


Assuntos
Adesão Celular , Titânio , Titânio/química , Ligantes , Animais , Integrinas/metabolismo , Integrinas/química , Camundongos , Humanos , Nanopartículas Metálicas/química , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Nanoestruturas/química , Proteínas de Sinalização YAP , Microscopia de Fluorescência
19.
ACS Appl Mater Interfaces ; 16(14): 17846-17856, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38549366

RESUMO

We introduce a novel approach for colloidal lithography based on the dry particle assembly into a dense monolayer on an elastomer, followed by mechanical transfer to a substrate of any material and curvature. This method can be implemented either manually or automatically and it produces large area patterns with the quality obtained by the state-of-the-art colloidal lithography at a very high throughput. We first demonstrated the fabrication of nanopatterns with a periodicity ranging between 200 nm and 2 µm. We then demonstrated two nanotechnological applications of this approach. The first one is antireflective structures, fabricated on silicon and sapphire, with different geometries including arrays of bumps and holes and adjusted for different spectral ranges. The second one is smart 3D nanostructures for mechanostimulation of T cells that are used for their effective proliferation, with potential application in cancer immunotherapy. This new approach unleashes the potential of bottom-up nanofabrication and paves the way for nanoscale devices and systems in numerous applications.

20.
Chemphyschem ; 14(17): 3944-52, 2013 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-24194383

RESUMO

To assess the potential of ionic liquids (ILs) as a solubilizing media that facilitates proton-transfer reactions, acridine prototropism is investigated using UV/Vis molecular absorbance as well as steady-state and time-resolved fluorescence with different ILs in the presence of a small amount of dilute acid or base. It is found that protonation and deprotonation of acridine, when dissolved in different ILs, can be triggered by the addition of a small amount of dilute aqueous HCl and NaOH, respectively, in both the ground and excited states, irrespective of the identity of the IL. However, the amount of dilute acid/base needed to protonate/deprotonate acridine dissolved in different ILs is found to vary from one IL to another. Steady-state fluorescence measurements also imply the presence of interactions between the acidic proton(s) of IL cation and excited acridine. The interconversion of neutral and protonated acridine, as well as the presence of a weakly fluorescent complex between excited acridine and the acidic proton(s) of the IL cation, is further corroborated by the parameters recovered from the fitting of the excited-state intensity-decay data. It is established that ILs as solubilizing media readily support facile proton transfer in both ground and excited states.


Assuntos
Acridinas/química , Líquidos Iônicos/química , Prótons , Água/química , Fluorescência
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