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1.
Nanotechnology ; 35(15)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38150740

RESUMO

Direct current plasma enhanced chemical vapor deposition (CVD) was employed to create polycrystalline diamond films from CH4/H2gaseous mixture at 98 mbar pressure and various substrate temperatures between 720 °C and 960 °C. The Si chips with patterns of periodic masked and open seeded zones were used as substrates. The mask free seeded areas evolved into polycrystalline diamond films after CVD process. The diamond crystallites of the films featured single crystal ordering individually with distinct cubic (100) or octahedral (111) facets on the film surfaces. Notably, specific growth conditions were determined for obtaining diamond films composed of the crystallites of nanometre and micrometre scale. These conditions are differing from those observed for non-pattern-prepared Si substrates. The nano-crystalline diamonds emerged within the 4.5-5 A current range, with growth conditions involving 3% CH4/H2mixture at 98 mbar. The micro-crystalline diamonds (MCDs) predominantly characterized by well-developed rectangular (100) crystal faces on the film surface were successfully grown with current settings of 5.5-6 A, under 3% CH4/H2mixture at 98 mbar. Furthermore, MCDs characterized by entirely crystalline (111) diamond faces forming CVD film surface were attained within a growth parameter range of 4.5-5.8 A, employing 3% CH4/H2mixture for certain samples, or alternatively, utilizing 5 A with a 1.5% CH4/H2mixture for others. Upon thorough evaluation, it was established that SiO2, TiO2, and Cr masks are well-suited materials for the planar patterning of both nano- and micro-crystalline diamond films, and the bottom-up approach can pave the way for the production of diamond planar structures through CVD, facilitated by electron beam lithography (EBL).

2.
Prep Biochem Biotechnol ; 54(2): 127-149, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37530797

RESUMO

In the modern era, inorganic nanoparticles have received profound attention as they possess boundless applications in various fields. Among these, vanadium-based nanoparticles (VNPs) are highly remarkable due to their inherent physiological and biological properties with many therapeutic and other applications, such as drug delivery systems for diseases like cancer, environmental remediation, energy storage, energy conversion, and photocatalysis. Moreover, physically, and chemically synthesized VNPs are very versatile, however, these synthesis routes cause concern to health and the environment due to the highly savage reaction conditions, using highly toxic and harsh chemicals, which compel the researchers to develop an eco-friendly, greener, and sustainable route for synthesis. In this outlook, to avoid the innumerable limitations, a bio approach is used over chemical and physical methods. This present review emphasis on the role of various biological components in the synthesis, especially Phyto-molecules that acts as capping and reducing agent, and solvent system for the nanoparticles synthesis. Furthermore, the influence of various factors on the biogenic synthesized nanoparticles has also been discussed. Finally, potential applications of as-synthesized VNPs, principally as an antimicrobial agent and their role as a nanomedicine, energy applications as a supercapacitor, and photocatalytic agents, have been discussed.


Assuntos
Nanopartículas Metálicas , Nanopartículas Metálicas/química , Vanádio , Química Verde , Nanomedicina , Compostos Fitoquímicos , Extratos Vegetais/química
3.
Nervenarzt ; 95(5): 467-473, 2024 May.
Artigo em Alemão | MEDLINE | ID: mdl-38668756

RESUMO

BACKGROUND: Early career scientists (ECS) are agents of change and driving forces in the promotion of mental health. The German Center for Mental Health (DZPG) is a powerful initiative to guide and support careers in the field of mental health. OBJECTIVE: The DZPG aims to make investments to educate, engage, excite, and empower ECS in an interdisciplinary and interinstitutional scientific community. STRUCTURES, TOPICS AND INITIATIVES: To achieve this, the ECS Board at the DZPG plays a central role and consists of 18 elected ECS representatives. The ECS culture gives members the right of voice and embraces bottom-to-top ideas and acknowledges autonomy and co-determination. The DZPG academy was developed to facilitate communication and networking and encourage collaboration among ECS members. The DZPG also navigates several key issues, such as equality, diversity, inclusion, family friendliness and work-life balance, which are essential for a functioning research landscape. The DZPG also extends opportunities to ECS to develop skills and competencies that are essential for contemporary ECS. It complements nationwide support for ECS with funding opportunities, mental health support at work, careers advice and guidance activities. Importantly, the ECS Board is committed to patient and public involvement and engagement, scientific communication and knowledge transfer to multiple settings. CONCLUSION: The DZPG will contribute to fostering ECS training programs for student and academic exchanges, collaborative research, and pooling of resources to acquire grants and scholarships. It will also support the establishment of hubs for ECS networks and promote the expansion of international competence of ECS in Germany.


Assuntos
Escolha da Profissão , Alemanha , Humanos , Saúde Mental , Colaboração Intersetorial , Objetivos Organizacionais , Pesquisadores , Relações Interinstitucionais
4.
Proteins ; 91(3): 412-435, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36287124

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy can reveal conformational states of a protein in physiological conditions. However, sparsely available NMR data for a protein with large degrees of freedom can introduce structural artifacts in the built models. Currently used state-of-the-art methods deriving protein structure and conformation from NMR deploy molecular dynamics (MD) coupled with simulated annealing for building models. We provide an alternate graph-based modeling approach, where we first build substructures from NMR-derived distance-geometry constraints combined in one shot to form the core structure. The remaining molecule with inadequate data is modeled using a hybrid approach respecting the observed distance-geometry constraints. One-shot structure building is rarely undertaken for large and sparse data systems, but our data-driven bottom-up approach makes this uniquely feasible by suitable partitioning of the problem. A detailed comparison of select models with state-of-art methods reveals differences in the secondary structure regions wherein the correctness of our models is confirmed by NMR data. Benchmarking of 106 protein-folds covering 38-282 length structures shows minimal experimental-constraint violations while conforming to other structure quality parameters such as the proper folding, steric clash, and torsion angle violation based on Ramachandran plot criteria. Comparative MD studies using select protein models from a state-of-art method and ours under identical experimental parameters reveal distinct conformational dynamics that could be attributed to protein structure-function. Our work is thus useful in building enhanced NMR-evidence-based models that encapsulate the contextual secondary and tertiary structure variations present during the experimentation and expand the scope of functional inference.


Assuntos
Proteínas , Conformação Proteica , Modelos Moleculares , Proteínas/química , Espectroscopia de Ressonância Magnética/métodos , Estrutura Secundária de Proteína
5.
Small ; 19(31): e2205957, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36610043

RESUMO

The discovery of carbon-based quantum dots (CQDs) has allowed opportunities for fluorescence bioimaging, tumor diagnosis and treatment, and photo-/electro-catalysis. Nevertheless, in the existing reviews related to the "bottom-up" approaches, attention is mainly paid to the applications of CQDs but not the formation mechanism of CQDs, which mainly derived from the high complexities during the synthesis of CQDs. Among the various synthetic methods, using small molecules as "building blocks", the development of a "bottom-up" approach has promoted the structural design, modulation of the photoluminescence properties, and control of the interfacial properties of CQDs. On the other hand, many works have demonstrated the "building blocks"-dependent properties of CQDs. In this review, from one of the most important variables, the relationships among intrinsic properties of "building blocks" and photoluminescence properties of CQDs are summarized. The topology, chirality, and free radical process are selected as descriptors for the intrinsic properties of "building blocks". This review focuses on the induction and summary of recent research results from the "bottom-up" process. Moreover, several empirical rules pertaining thereto are also proposed.

6.
Small ; 19(14): e2206063, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36624578

RESUMO

Zinc oxide (ZnO) is a thermally stable n-type semiconducting material. ZnO 2D nanosheets have mainly gained substantial attention due to their unique properties, such as direct bandgap and strong excitonic binding energy at room temperature. These are widely utilized in piezotronics, energy storage, photodetectors, light-emitting diodes, solar cells, gas sensors, and photocatalysis. Notably, the chemical properties and performances of ZnO nanosheets largely depend on the nano-structuring that can be regulated and controlled through modulating synthetic strategies. Two synthetic approaches, top-down and bottom-up, are mainly employed for preparing ZnO 2D nanomaterials. However, owing to better results in producing defect-free nanostructures, homogenous chemical composition, etc., the bottom-up approach is extensively used compared to the top-down method for preparing ZnO 2D nanosheets. This review presents a comprehensive study on designing and developing 2D ZnO nanomaterials, followed by accenting its potential applications. To begin with, various synthetic strategies and attributes of ZnO 2D nanosheets are discussed, followed by focusing on methodologies and reaction mechanisms. Then, their deliberation toward batteries, supercapacitors, electronics/optoelectronics, photocatalysis, sensing, and piezoelectronic platforms are further discussed. Finally, the challenges and future opportunities are featured based on its current development.

7.
Med Health Care Philos ; 26(4): 583-589, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37584838

RESUMO

Jesper Ahlin Marceta published an article in this journal in which he formulated his "argument from testability", stating that it is impossible, at least practically, to operationalize procedural authenticity. That is, using procedural accounts of authenticity, one cannot reliably differentiate between authentic and inauthentic desires. There are roughly two ways to respond to the argument from testability: top-down and bottom-up. Several authors have endeavored the top-down approach by trying to show that some conceptions of authenticity might be operationalizable after all. At present, however, the bottom-up approach has not been put to the test. That is, no attempt has been made to use a currently existing assessment tool to guide the development of an account of authenticity. In this paper, I will investigate what it means to develop an account of authenticity bottom-up based on measures of concordance. More specifically, I will investigate the following three research questions. First, how do concordance and authenticity relate at a conceptual level? As crucial similarities exist between these concepts, concordance measures seem to offer a good starting point for the bottom-up approach. Second, how do judgements of concordance differ from judgements of authenticity? Both their scope and the way they are justified will turn out to be different. This suggests novel ways to react to Marceta's argument from testability. Third, should we develop a theory of concordance? The positive answer to this question will point towards a central limitation of the bottom-up approach.

8.
Environ Sci Technol ; 56(15): 11080-11090, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35822463

RESUMO

The quantification and comparison of microplastic contamination of sediments are affected by sample heterogeneity and the systematic and random effects affecting sample analysis. The quantification and combination of these components in the measurement uncertainty allows the objective interpretation of analysis results. This work presents the first detailed evaluation of the uncertainty of microplastic contamination quantification in sediments. The random and systematic effects affecting microplastic counts are modeled by the Poisson-lognormal distribution with inputs estimated from duplicate sediment analysis and the analysis of sediments spiked with microparticles. The uncertainty from particle counting was combined with the uncertainty from the determination of the dry mass of the analytical portion by the Monte Carlo method. The developed methodology was implemented in a user-friendly spreadsheet made available as the Supporting Information. The contamination of sediment samples collected in various inland Portuguese waters was determined, ranging from [0; 160] to [361; 2932] kg-1 for a 99% confidence level, and compared by assessing if the difference between contamination levels is equivalent to zero for the same confidence level. Several samples proved to have metrologically different microplastic contamination. This work represents a contribution to the objectivity of the assessment of environmental contamination with microplastics.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos/análise , Plásticos/análise , Incerteza , Poluentes Químicos da Água/análise
9.
Environ Sci Technol ; 56(24): 18050-18059, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36455072

RESUMO

Roads play a key role in movements of goods and people but require large amounts of materials emitting greenhouse gases to be produced. This study assesses the global road material stock and the emissions associated with materials' production. Our bottom-up approach combines georeferenced paved road segments with road length statistics and archetypical geometric characteristics of roads. We estimate road material stock to be of 254 Gt. If we were to build these roads anew, raw material production would emit 8.4 GtCO2-eq. Per capita stocks range from 0.2 t/cap in Chad to 283 t/cap in Iceland, with a median of 20.6 t/cap. If the average per capita stock in Africa was to reach the current European level, 166 Gt of road materials, equivalent to the road material stock in North America and in East and South Asia, would be consumed. At the urban scale, road material stock increases with the urban area, population density, and GDP per capita, emphasizing the need for containing urban expansion. Our study highlights the challenges in estimating road material stock and serves as a basis for further research into infrastructure resource management.


Assuntos
Gases de Efeito Estufa , Humanos , África , Ásia Meridional , América do Norte
10.
BMC Palliat Care ; 21(1): 67, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35524257

RESUMO

BACKGROUND: Hospitals are globally an important place of care for dying people and the most frequent place of death in Germany (47%), but at the same time, the least preferred one - for both patients and their relatives. Important indicators and outcome variables indexing quality of care in the dying phase are available, and various proposals to achieve corresponding quality objectives exist. However, they are not yet sufficiently adapted to the heterogeneous needs of individual hospital wards. METHODS: This multi-centre single-arm pre-post study aims at the development and implementation of context-specific measures in everyday clinical practice, followed by evaluating this approach. Therefore, (1) already existing measures regarding optimal care in the dying phase are identified applying a systematic literature review as well as an online survey and a symposium with experts. Supported by the thereby generated collection of measures, (2) a stratified sample of ten teams of different wards from two university hospitals select suitable measures and implement them in their everyday clinical practice. Circumstances of patients' deaths on the selected wards are recorded twice, at baseline before application of the self-chosen measures and afterwards in a follow-up survey. Retrospective file analysis of deceased persons, quantitative staff surveys as well as qualitative multi-professional focus groups and interviews with relatives form the data basis of the pre-post evaluation. (3) Results are reviewed regarding their transferability to other hospitals and disseminated (inter-)nationally. DISCUSSION: Measures that are easy to implement and appropriate to the specific situation are supposed to significantly improve the quality of care during the dying phase in hospitals and contribute to the well-being of dying patients and their relatives. Successful implementation of those measures requires consideration of the individual conditions and needs of patients and their relatives-but also of the health professionals-on the different hospital wards. Therefore, a bottom-up approach, in which the ward-specific situation is first analysed in detail and then the staff itself selects and implements measures to improve care, appears most promising for optimising care in the dying phase in hospitals. TRIAL REGISTRATION: The study is registered in the German Clinical Trials Register ( DRKS00025405 ).


Assuntos
Hospitais , Assistência Terminal , Alemanha , Humanos , Estudos Multicêntricos como Assunto , Cuidados Paliativos , Pacientes , Estudos Retrospectivos , Inquéritos e Questionários , Revisões Sistemáticas como Assunto
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