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1.
Telemed J E Health ; 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38436592

RESUMO

Introduction: Telehealth in India is growing rapidly and represents a strategy to promote affordable, inclusive, timely and safe access to healthcare. Yet there is a risk that telehealth increases inequity due to the digital divide and existing poor health literacy. Methods: A scoping review was conducted to explore use of telehealth in India during and following the COVID-19 pandemic by people with disabilities to inform strategies to increase equity of telehealth for people with disabilities. Of 1966 studies from the initial search in four databases and three specific telehealth journals, 20 sources met the inclusion criteria, limited to a focus on physical disability in India. Results: Findings showed examples of how people with disabilities can exercise increased control in the timing of appointments, convenience of receiving services from home and not having to travel to clinics or hospitals, and platform preference through tools and applications already familiar to them. Carers and families of people with disabilities were described as highly valued stakeholders with important roles in the uptake and effectiveness of telehealth for people with disabilities. The identified benefits of telehealth resulted in high levels of user satisfaction due to increased control and convenience, however, systemic barriers for accessibility remain. Conclusion: This review suggested that if telehealth is not designed intentionally to change the status quo for people with disabilities and prioritize equity, then the benefits may not be sustainable. Recommendations for telehealth India are provided, based on both findings from the literature and analysis of results.

2.
Tissue Eng Regen Med ; 21(1): 21-52, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37882981

RESUMO

Fabrication of functional organs is the holy grail of tissue engineering and the possibilities of repairing a partial or complete liver to treat chronic liver disorders are discussed in this review. Liver is the largest gland in the human body and plays a responsible role in majority of metabolic function and processes. Chronic liver disease is one of the leading causes of death globally and the current treatment strategy of organ transplantation holds its own demerits. Hence there is a need to develop an in vitro liver model that mimics the native microenvironment. The developed model should be a reliable to understand the pathogenesis, screen drugs and assist to repair and replace the damaged liver. The three-dimensional bioprinting is a promising technology that recreates in vivo alike in vitro model for transplantation, which is the goal of tissue engineers. The technology has great potential due to its precise control and its ability to homogeneously distribute cells on all layers in a complex structure. This review gives an overview of liver tissue engineering with a special focus on 3D bioprinting and bioinks for liver disease modelling and drug screening.


Assuntos
Bioimpressão , Hepatopatias , Humanos , Engenharia Tecidual/métodos , Bioimpressão/métodos , Impressão Tridimensional , Hepatopatias/terapia
3.
3D Print Addit Manuf ; 10(5): 1140-1163, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37886418

RESUMO

A three-dimensional (3D) printing is a robotically controlled state-of-the-art technology that is promising for all branches of engineering with a meritorious emphasis to biomedical engineering. The purpose of 3D printing (3DP) is to create exact superstructures without any framework in a brief period with high reproducibility to create intricate and complex patient-tailored structures for organ regeneration, drug delivery, imaging processes, designing personalized dose-specific tablets, developing 3D models of organs to plan surgery and to understand the pathology of disease, manufacturing cost-effective surgical tools, and fabricating implants and organ substitute devices for prolonging the lives of patients, etc. The formulation of bioinks and programmed G codes help to obtain precise 3D structures, which determines the stability and functioning of the 3D-printed structures. Three-dimensional printing for medical applications is ambitious and challenging but made possible with the culmination of research expertise from various fields. Exploring and expanding 3DP for biomedical and clinical applications can be life-saving solutions. The 3D printers are cost-effective and eco-friendly, as they do not release any toxic pollutants or waste materials that pollute the environment. The sampling requirements and processing parameters are amenable, which further eases the production. This review highlights the role of 3D printers in the health care sector, focusing on their roles in tablet development, imaging techniques, disease model development, and tissue regeneration.

4.
J Phys Chem Lett ; 14(24): 5497-5504, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37289825

RESUMO

Pressure-induced phases of MAPbBr3 were investigated at room temperature in the range of 0-2.8 GPa by ab initio molecular dynamics. Two structural transitions at 0.7 GPa (cubic → cubic) and 1.1 GPa (cubic → tetragonal) involved both the inorganic host (lead bromide) and the organic guest (MA). MA dipoles behave like a liquid crystal undergoing isotropic → isotropic and isotropic → oblate nematic transitions as pressure confines their orientational fluctuations to a crystal plane. Beyond 1.1 GPa, the MA ions lie alternately along two orthogonal directions in the plane forming stacks perpendicular to it. However, the molecular dipoles are statically disordered, leading to stable polar and antipolar MA domains in each stack. H-Bond interactions, which primarily mediate host-guest coupling, facilitate the static disordering of MA dipoles. Interestingly, high pressures suppress CH3 torsional motion, emphasizing the role of C-H···Br bonds in the transitions.

5.
JMIR Infodemiology ; 3: e44207, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37012998

RESUMO

Background: An infodemic is excess information, including false or misleading information, that spreads in digital and physical environments during a public health emergency. The COVID-19 pandemic has been accompanied by an unprecedented global infodemic that has led to confusion about the benefits of medical and public health interventions, with substantial impact on risk-taking and health-seeking behaviors, eroding trust in health authorities and compromising the effectiveness of public health responses and policies. Standardized measures are needed to quantify the harmful impacts of the infodemic in a systematic and methodologically robust manner, as well as harmonizing highly divergent approaches currently explored for this purpose. This can serve as a foundation for a systematic, evidence-based approach to monitoring, identifying, and mitigating future infodemic harms in emergency preparedness and prevention. Objective: In this paper, we summarize the Fifth World Health Organization (WHO) Infodemic Management Conference structure, proceedings, outcomes, and proposed actions seeking to identify the interdisciplinary approaches and frameworks needed to enable the measurement of the burden of infodemics. Methods: An iterative human-centered design (HCD) approach and concept mapping were used to facilitate focused discussions and allow for the generation of actionable outcomes and recommendations. The discussions included 86 participants representing diverse scientific disciplines and health authorities from 28 countries across all WHO regions, along with observers from civil society and global public health-implementing partners. A thematic map capturing the concepts matching the key contributing factors to the public health burden of infodemics was used throughout the conference to frame and contextualize discussions. Five key areas for immediate action were identified. Results: The 5 key areas for the development of metrics to assess the burden of infodemics and associated interventions included (1) developing standardized definitions and ensuring the adoption thereof; (2) improving the map of concepts influencing the burden of infodemics; (3) conducting a review of evidence, tools, and data sources; (4) setting up a technical working group; and (5) addressing immediate priorities for postpandemic recovery and resilience building. The summary report consolidated group input toward a common vocabulary with standardized terms, concepts, study designs, measures, and tools to estimate the burden of infodemics and the effectiveness of infodemic management interventions. Conclusions: Standardizing measurement is the basis for documenting the burden of infodemics on health systems and population health during emergencies. Investment is needed into the development of practical, affordable, evidence-based, and systematic methods that are legally and ethically balanced for monitoring infodemics; generating diagnostics, infodemic insights, and recommendations; and developing interventions, action-oriented guidance, policies, support options, mechanisms, and tools for infodemic managers and emergency program managers.

6.
J Phys Chem B ; 126(37): 7077-7087, 2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-36083211

RESUMO

The remarkable photostability of canonical nucleobases makes them ideal building blocks for DNA and RNA. Even minor structural changes are expected to lead to drastic alteration of their subpicosecond excited state lifetimes. However, it is interesting to note that while the 9H- and 7H-amino tautomers of adenine possess drastically different lifetimes, 9H- and 7H-keto guanine possess similar excited state lifetimes. With an aim to explain this unexpected difference in sensitivity of lifetimes to tautomerization, we have investigated the excited state relaxation mechanism of UV-excited adenine and guanine tautomers using surface hopping based nonadiabatic molecular dynamics. We find that internal conversion in both guanine tautomers is almost barrierless while both adenine tautomers encounter significant barriers before they can deactivate. Moreover, the major deactivation channel (C2-puckering) in 9H-amino adenine is overall more efficient than the one (C6-puckering) in the 7H-amino form. We trace this difference to the frequent rotation of the amino group which disrupts its conjugation with the heterocyclic ring thereby reducing the strength of nonadiabatic coupling and, hence, delaying internal conversion.


Assuntos
Adenina , Simulação de Dinâmica Molecular , Adenina/química , Guanina/química , RNA
7.
Phys Chem Chem Phys ; 24(19): 11668-11679, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35506522

RESUMO

Methane has emerged as a promising fuel due to its abundance and clean combustion properties. It is also a raw material for various value-added chemicals. However, the conversion of methane to other chemicals such as olefins, aromatics, and hydrocarbons is a difficult task. In recent years, ionic iron carbide clusters have been explored as potential catalysts for efficient direct methane conversion. Herein, we have investigated the gas-phase methane conversion process on various neutral iron carbide clusters with different Fe:C ratios using density functional theory. Reaction pathways were studied on mononuclear and trinuclear iron carbide clusters in the three lowest energy spin multiplicity channels. Three descriptors - methane binding energy, the effective energy barrier for C-H bond activation, and the effective energy required for methyl radical evolution - were chosen to identify the best catalyst among the clusters considered. Isomers of Fe3C6 (Fe3C6-iso) and Fe3C9 (Fe3C9-iso) are recognized as being the most promising catalysts among all the clusters considered here because they require the least methyl radical evolution energy, a step that is crucial in methane conversion to higher hydrocarbon but also requires the most energy.

8.
Chemphyschem ; 23(14): e202200085, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35491429

RESUMO

Water oxidation activity of pristine NiOOH is greatly enhanced by doping it with Fe. However, the precise role of Fe is still being debated. Using a first-principles DFT+U approach, we investigate the direct and indirect roles of Fe in enhancing the oxygen evolution reaction (OER) activity of NiOOH monolayers. Considering two Mars-Van-Krevelen mechanisms of OER based on the source of O-O bond formation, we show that a mechanism involving the coupling of lattice oxygen is generally more favorable than water nucleophilic attack on lattice oxygen. On doping with Fe, the overpotential of NiOOH is reduced by 0.33 V, in excellent agreement with experimental findings. Introducing Fe at active sites results in different potential determining steps (PDS) in the two mechanisms. The Ni sites in pristine and Fe-doped NiOOH have the same PDS regardless of the mechanism. The Fe sites not only have the lowest overpotential but also decrease the overpotential for Ni sites.

9.
Regen Med ; 16(8): 775-802, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34427104

RESUMO

The concept of tissue engineering involves regeneration and repair of damaged tissue and organs using various combinations of cells, growth factors and scaffolds. The extracellular matrix (ECM) forms the integral part of the scaffold to induce cell proliferation thereby leading to new tissue formation. Decellularization technique provides decellularized ECM (dECM), free of cells while preserving the in vivo biomolecules. In this review, we focus on the detailed methodology of diverse decellularization techniques for various organs of different animals, and the biomedical applications employing the dECM. A culmination of different methods of decellularization is optimized, which offers a suitable microenvironment mimicking the native in vivo topography for in vitro organ regeneration. A detailed assessment of the dECM provides information on the microarchitecture, presence of ECM proteins, biocompatibility and cell proliferation. dECM has also been processed as scaffolds and drug-delivery vehicles, and utilized for regeneration.


Assuntos
Engenharia Biomédica , Alicerces Teciduais , Animais , Matriz Extracelular , Engenharia Tecidual
10.
Phys Chem Chem Phys ; 23(15): 9448-9456, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33885052

RESUMO

The pressure induced polymerization of molecular solids is an appealing route to obtain pure, crystalline polymers without the need for radical initiators. Here, we report a detailed density functional theory (DFT) study of the structural and chemical changes that occur in defect free solid acrylamide, a hydrogen bonded crystal, when it is subjected to hydrostatic pressures. While our calculations are able to reproduce experimentally measured pressure dependent spectroscopic features in the 0-20 GPa range, our atomistic analysis predicts polymerization in acrylamide at a pressure of ∼23 GPa at 0 K albeit through large enthalpy barriers. Interestingly, we find that the two-dimensional hydrogen bond network in acrylamide templates topochemical polymerization by aligning the atoms through an anisotropic response at low pressures. This results not only in conventional C-C, but also unusual C-O polymeric linkages, as well as a new hydrogen bonded framework, with both N-HO and C-HO bonds. Using a simple model for thermal effects, we also show that at 300 K, higher pressures significantly accelerate the transformation into polymers by lowering the barrier. Thus, application of pressure offers an alternative route for topochemical polymerization when higher temperatures are undesirable.

11.
J Am Chem Soc ; 143(4): 2025-2036, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33471537

RESUMO

Excited anthracene is well-known to photodimerize and not to exhibit excimer emission in isotropic organic solvents. Anthracene (AN) forms two types of supramolecular host-guest complexes (2:1 and 2:2, H:G) with the synthetic host octa acid in aqueous medium. Excitation of the 2:2 complex results in intense excimer emission, as reported previously, while the 2:1 complex, as expected, yields only monomer emission. This study includes confirming of host-guest complexation by NMR, probing the host-guest structure by molecular dynamics simulation, following the dynamics AN molecules in the excited state by ultrafast time-resolved experiments, and mapping of the excited surface through quantum chemical calculations (QM/MM-TDDFT method). Importantly, time-resolved emission experiments revealed the excimer emission maximum to be time dependent. This observation is unique and is not in line with the textbook examples of time-independent monomer-excimer emission maxima of aromatics in solution. The presence of at least one intermediate between the monomer and the excimer is inferred from time-resolved area normalized emission spectra. Potential energy curves calculated for the ground and excited states of two adjacent anthracene molecules via the QM/MM-TDDFT method support the model proposed on the basis of time-resolved experiments. The results presented here on the excited-state behavior of a well-investigated aromatic molecule, namely the parent anthracene, establish that the behavior of a molecule drastically changes under confinement. The results presented here have implications on the behavior of molecules in biological systems.

12.
Chem Commun (Camb) ; 56(89): 13832-13835, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33084637

RESUMO

Chemo- and site-specific modifications in oligonucleotides have wide applicability as mechanistic probes in chemical biology. However, methods that label specific sites in nucleic acids are scarce, especially for labeling DNA/RNA from biological or enzymatic sources rather than synthetic ones. Here we have employed a classical reaction, reductive amination, to selectively functionalize the N2-amine of guanosine and 2'-deoxyguanosine monophosphate (GMP/dGMP). This method specifically modifies guanine in DNA and RNA oligonucleotides, while leaving the other nucleobases unaffected. Using this approach, we have successfully incorporated a reactive handle chemoselectively into nucleic acids for further functionalization and downstream applications.


Assuntos
Aminas/química , Guanina/química , Oligonucleotídeos/química , Aminação , Conformação de Ácido Nucleico , Oxirredução
13.
Phys Rev Lett ; 123(10): 107201, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31573301

RESUMO

Epitaxial strain has been shown to drive structural phase transitions along with novel functionalities in perovskite-based thin films. Aliovalent doping at the A site can drive an insulator-to-metal and magnetic transitions in perovskites along with a variety of interesting structural and electronic phenomena. Using first-principles calculations, we predict the formation of a multiferroic half-metallic phase with a large magnetic moment in the double perovskite, Bi_{2}FeCrO_{6}, by coupling epitaxial strain with A-site hole doping. We also demonstrate that epitaxial strain can be used to manipulate the hole states created by doping to induce half-metal to insulator, antipolar to polar, antiferromagnetic to ferromagnetic, orbital ordering and charge ordering transitions. Our work also suggests that hole doping under strain could lead to mitigation of issues related to antisite defects and lowered magnetization in thin films of the material.

14.
Glob Public Health ; 14(12): 1718-1732, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31094290

RESUMO

India has 600 million young people, more than any other country in the world. Mental illness is the leading burden of disease for young people, and those affected experience restrictions in social participation that compromise recovery. The aim of this study was to assess the impact of a peer-led, community-based, participatory group intervention on social inclusion and mental health among 142 young people affected by psycho-social disability (PSD) in Dehradun district, Uttarakhand. Qualitative data were obtained via in-depth interviews and focus-group discussions. A realist evaluation identified contextual factors, mechanisms and outcomes to develop the programme theory. Group participants described intermediate outcomes including establishment of new peer friendship networks, increased community participation, greater self-efficacy (for young women particularly), and improved public image (for young men) that are likely to have contributed to the primary outcomes of greater (self-perceived) social inclusion and improved mental health (as assessed quantitatively). Mechanisms were identified that explain the link between intervention and outcomes. These findings demonstrate the effectiveness of a brief intervention to improve mental health and social inclusion for young people with PSD and are potentially relevant to programme implementers and policy-makers working with young people and promoting social inclusion, in other low- and middle-income settings.


Assuntos
Promoção da Saúde/métodos , Relações Interpessoais , Pessoas Mentalmente Doentes , Facilitação Social , Pesquisa Participativa Baseada na Comunidade , Grupos Focais , Humanos , Índia , Entrevistas como Assunto , Grupo Associado , Projetos Piloto , Avaliação de Programas e Projetos de Saúde , Pesquisa Qualitativa , Autoeficácia
15.
J Phys Condens Matter ; 30(38): 385603, 2018 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-30106380

RESUMO

The Harper equation arising out of a tight-binding model of electrons on a honeycomb lattice subject to a uniform magnetic field perpendicular to the plane is studied. Contrasting and complementary approaches involving von Neumann entropy, fidelity, fidelity susceptibility, and multifractal analysis are employed to characterize the phase diagram. Remarkably even in the absence of the quasi-periodic on-site potential term, the Hamiltonian allows for a metal-insulator transition. The phase diagram consists of three phases: two metallic phases and an insulating phase. A variant model where next nearest neighbor hopping is included, exhibits a mobility edge and does not allow for a simple single phase diagram characterizing all the eigenstates.

16.
Opt Express ; 23(11): 14085-94, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26072777

RESUMO

In this article, we experimentally demonstrate for the first time that photobleaching (PB) can be induced in morphologically disordered a-Se thin film, an observation which is opposite of the previously well-known photodarkening (PD) effects in morphologically ordered films. Further, the optical response of the film shows many fold increase with increase in control beam intensity. To explain the observed extraordinary phenomenon, we have proposed a model based on the morphological disorder of a modified surface and its subsequent photo-annealing. Our results demonstrate an efficient and yet simple new method to engineer the optical response of photosensitive thin films. We envision that this process can open up many avenues in optical field-enhanced absorption-based technologies.

17.
Chemistry ; 20(47): 15587-604, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25284044

RESUMO

A study of the scope and limitations of varying the ligand framework around the dinuclear core of FvRu2 in its function as a molecular solar thermal energy storage framework is presented. It includes DFT calculations probing the effect of substituents, other metals, and CO exchange for other ligands on ΔHstorage . Experimentally, the system is shown to be robust in as much as it tolerates a number of variations, except for the identity of the metal and certain substitution patterns. Failures include 1,1',3,3'-tetra-tert-butyl (4), 1,2,2',3'-tetraphenyl (9), diiron (28), diosmium (24), mixed iron-ruthenium (27), dimolybdenum (29), and ditungsten (30) derivatives. An extensive screen of potential catalysts for the thermal reversal identified AgNO3 -SiO2 as a good candidate, although catalyst decomposition remains a challenge.


Assuntos
Alcadienos/química , Complexos de Coordenação/síntese química , Ciclopentanos/química , Metais/química , Energia Solar , Catálise , Complexos de Coordenação/química , Cristalografia por Raios X , Cinética , Conformação Molecular , Termodinâmica
18.
J Phys Chem B ; 117(40): 12276-85, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-24041295

RESUMO

Efficiency of photoinduced charge transfer (CT) reactions in supramolecular assemblies is often compromised due to the rigid parametrization of acceptable donor-acceptor (D-A) distances and orientations. Using a combined approach of time-resolved optical measurements and electronic structure studies guided by molecular dynamics (MD) simulations, we demonstrate that dynamic control on CT rate exists for quenching of hydroxy-anthraquinones in donor aniline-like solvents. We find that anthraquinone ring deformation modes control the kinetics of CT within ∼300-700 fs by modulating the D-A electronic couplings. Our work demonstrates that low-frequency motions have to be critically understood for all such D-A pairs, and generates a rational methodology for utilization of hydroxy-anthraquinone acceptors in numerous photoactive architectures.


Assuntos
Antraquinonas/química , Técnicas Eletroquímicas , Lasers , Simulação de Dinâmica Molecular , Solventes/química , Análise Espectral Raman
19.
ACS Nano ; 5(5): 3701-6, 2011 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-21480634

RESUMO

We have used scanning tunneling microscopy, Auger electron spectroscopy, and density functional theory calculations to investigate thermal and photoinduced structural transitions in (fulvalene)tetracarbonyldiruthenium molecules (designed for light energy storage) on a Au(111) surface. We find that both the parent complex and the photoisomer exhibit striking thermally induced structural phase changes on Au(111), which we attribute to the loss of carbonyl ligands from the organometallic molecules. Density functional theory calculations support this conclusion. We observe that UV exposure leads to pronounced structural change only in the parent complex, indicative of a photoisomerization reaction.


Assuntos
Ouro/química , Ouro/efeitos da radiação , Modelos Químicos , Compostos Orgânicos/química , Compostos Orgânicos/efeitos da radiação , Simulação por Computador , Transferência de Energia/efeitos da radiação , Luz , Temperatura
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