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1.
Glob Chang Biol ; 27(4): 941-955, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33222345

RESUMEN

Among the global coordinated patterns in soil temperature and methane emission from wetlands, a declining trend of optimal soil temperature for methane emissions from low to high latitudes has been witnessed, while the corresponding trend along the altitudinal gradient has not yet been investigated. We therefore selected two natural wetlands located at contrasting climatic zones from foothill and mountainside of Nepal Himalayas, to test: (1) whether the optimal temperature for methane emissions decreases from low to high altitude, and (2) whether there is a difference in temperature sensitivity of methane emissions from those wetlands. We found significant spatial and temporal variation of methane emissions between the two wetlands and seasons. Soil temperature was the dominant driver for seasonal variation in methane emissions from both wetlands, though its effect was perplexed by the level of standing water, aquatic plants, and dissolved organic carbon, particularly in the deep water area. When integrative comparison was conducted by adding the existing data from wetlands of diverse altitudes, and the latitude-for-altitude effect was taken into account, we found the baseline soil temperatures decrease whilst the altitude rises with respect to a rapid increase in methane emission from all wetlands, however, remarkably higher sensitivity of methane emissions to soil temperature (apparent Q10 ) was found in mid-altitude wetland. We provide the first evidence of an apparent decline in optimal temperature for methane emissions with increasing elevation. These findings suggest a convergent pattern of methane emissions with respect to seasonal temperature shifts from wetlands along altitudinal gradient, while a divergent pattern in temperature sensitivities exhibits a single peak in mid-altitude.


Asunto(s)
Metano , Humedales , Altitud , Metano/análisis , Nepal , Suelo , Temperatura
2.
AAPS PharmSciTech ; 22(3): 127, 2021 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-33835317

RESUMEN

Being a candidate of BCS class II, dolutegravir (DTG), a recently approved antiretroviral drug, possesses solubility issues. The current research was aimed to improve the solubility of the DTG and thereby enhance its efficacy using the solid dispersion technique. In due course, the miscibility study of the drug was performed with different polymers, where Poloxamer 407 (P407) was found suitable to move forward. The solid dispersion of DTG and P407 was formulated using solvent evaporation technique with a 1:1 proportion of drug and polymer, where the solid-state characterization was performed using differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffraction. No physicochemical interaction was found between the DTG and P407 in the fabricated solid dispersion; however, crystalline state of the drug was changed to amorphous as evident from the X-ray diffractogram. A rapid release of DTG was observed from the solid dispersion (>95%), which is highly significant (p<0.05) as compared to pure drug (11.40%), physical mixture (20.07%) and marketed preparation of DTG (35.30%). The drug release from the formulated solid dispersion followed Weibull model kinetics. Finally, the rapid drug release from the solid dispersion formulation revealed increased Cmax (14.56 µg/mL) when compared to the physical mixture (4.12 µg/mL) and pure drug (3.45 µg/mL). This was further reflected by improved bioavailability of DTG (AUC: 105.99±10.07 µg/h/mL) in the experimental Wistar rats when compared to the AUC of animals administered with physical mixture (54.45±6.58 µg/h/mL) and pure drug (49.27±6.16 µg/h/mL). Therefore, it could be concluded that the dissolution profile and simultaneously the bioavailability of DTG could be enhanced by means of the solid dispersion platform using the hydrophilic polymer, P407, which could be projected towards improved efficacy of the drug in HIV/AIDS.


Asunto(s)
Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/farmacocinética , Terapia Antirretroviral Altamente Activa/métodos , Infecciones por VIH/tratamiento farmacológico , Compuestos Heterocíclicos con 3 Anillos/administración & dosificación , Compuestos Heterocíclicos con 3 Anillos/farmacocinética , Oxazinas/administración & dosificación , Oxazinas/farmacocinética , Piperazinas/administración & dosificación , Piperazinas/farmacocinética , Piridonas/administración & dosificación , Piridonas/farmacocinética , Animales , Fármacos Anti-VIH/uso terapéutico , Área Bajo la Curva , Disponibilidad Biológica , Composición de Medicamentos , Liberación de Fármacos , Excipientes , Compuestos Heterocíclicos con 3 Anillos/uso terapéutico , Masculino , Oxazinas/uso terapéutico , Piperazinas/uso terapéutico , Poloxámero , Piridonas/uso terapéutico , Ratas , Ratas Wistar , Solubilidad , Difracción de Rayos X
3.
Environ Monit Assess ; 188(11): 645, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27796830

RESUMEN

While deliberations relating to negative consequences of large dams on the environment continue to dominate world attention, positive benefits provided by small dams, also known as check dams, go unobserved. Besides, little is known about the potential of check dams in mitigating global warming impacts due to less data availability. Small dams are usually commissioned to private contractors who do not have clear mandate from their employers to post their work online for public scrutiny. As a result, statistics on the design, cost, and materials used to build check dams are not available in public domain. However, this review paper presents data for the first time on the often ignored potential of check dams mitigating climate-induced hydrological threats. We hope that the scientific analysis presented in this paper will promote further research on check dams worldwide to better comprehend their eco-friendly significance serving society.


Asunto(s)
Ambiente , Ríos , Recursos Hídricos , Abastecimiento de Agua , Cambio Climático , Conservación de los Recursos Naturales , Monitoreo del Ambiente , Hidrología
4.
PLoS One ; 19(3): e0296246, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38507371

RESUMEN

This study examines the intersectional role of citizenship and gender with career self-efficacy amongst 10,803 doctoral and postdoctoral trainees in US universities. These biomedical trainees completed surveys administered by 17 US institutions that participated in the National Institutes of Health Broadening Experiences in Scientific Training (NIH BEST) Programs. Findings indicate that career self-efficacy of non-citizen trainees is significantly lower than that of US citizen trainees. While lower career efficacy was observed in women compared with men, it was even lower for non-citizen female trainees. Results suggest that specific career interests may be related to career self-efficacy. Relative to US citizen trainees, both male and female non-citizen trainees showed higher interest in pursuing a career as an academic research investigator. In comparison with non-citizen female trainees and citizen trainees of all genders, non-citizen male trainees expressed the highest interest in research-intensive (and especially principal investigator) careers. The authors discuss potential causes for these results and offer recommendations for increasing trainee career self-efficacy which can be incorporated into graduate and postdoctoral training.


Asunto(s)
Investigación Biomédica , Humanos , Masculino , Femenino , Estados Unidos , Educación de Postgrado , Ciudadanía , National Institutes of Health (U.S.) , Investigadores/educación , Selección de Profesión
5.
PLoS One ; 18(3): e0280608, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36857379

RESUMEN

The present study examines racial, ethnic, and gender disparities in career self-efficacy amongst 6077 US citizens and US naturalized graduate and postdoctoral trainees. Respondents from biomedical fields completed surveys administered by the National Institutes of Health Broadening Experiences in Scientific Training (NIH BEST) programs across 17 US institutional sites. Graduate and postdoctoral demographic and survey response data were examined to evaluate the impact of intersectional identities on trainee career self-efficacy. The study hypothesized that race, ethnicity and gender, and the relations between these identities, would impact trainee career self-efficacy. The analysis demonstrated that racial and ethnic group, gender, specific career interests (academic principal investigator vs. other careers), and seniority (junior vs. senior trainee level) were, to various degrees, all associated with trainee career self-efficacy and the effects were consistent across graduate and postdoctoral respondents. Implications for differing levels of self-efficacy are discussed, including factors and events during training that may contribute to (or undermine) career self-efficacy. The importance of mentorship for building research and career self-efficacy of trainees is discussed, especially with respect to those identifying as women and belonging to racial/ethnic populations underrepresented in biomedical sciences. The results underscore the need for change in the biomedical academic research community in order to retain a diverse biomedical workforce.


Asunto(s)
Investigación Biomédica , Autoeficacia , Estados Unidos , Femenino , Humanos , Etnicidad , Instituciones de Salud , Marco Interseccional
6.
Gels ; 9(2)2023 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-36826300

RESUMEN

Dolutegravir's therapeutic effectiveness in the management of neuroAIDS is mainly limited by its failure to cross the blood-brain barrier. However, lipid-based nanovesicles such as nanoemulsions have demonstrated their potential for the brain targeting of various drugs by intranasal delivery. Thus, the purpose of this study was to develop a Dolutegravir-loaded nanoemulsion-based in situ gel and evaluate its prospective for brain targeting by intranasal delivery. Dolutegravir-loaded nanoemulsions were prepared using dill oil, Tween® 80, and Transcutol® P. Optimization of the nanoemulsion particle size and drug release was carried out using a simplex lattice design. Formulations (F1-F7 and B1-B6) were assessed for various pharmaceutical characteristics. Ex vivo permeation and ciliotoxicity studies of selected in situ gels (B1) were conducted using sheep nasal mucosa. Drug targeting to the brain was assessed in vivo in rats following the nasal delivery of B1. The composition of oil, surfactant, and cosurfactant significantly (p < 0.05) influenced the dependent variables (particle size and % of drug release in 8 h). Formulation B1 exhibits pharmaceutical characteristics that are ideal for intranasal delivery. The mucosal steady-state flux noticed with BI was significantly greater (p < 0.005) than for the control gel. A histopathology of nasal mucosa treated with BI showed no signs of toxicity or cellular damage. Intranasal administration of B1 resulted in greater Cmax (~six-fold, p < 0.0001) and AUC0-α (~five-fold, p < 0.0001), and decreased Tmax (1 h) values in the brain, compared to intravenous administration. Meantime, the drug level in the plasma was relatively low, suggesting less systemic exposure to Dolutegravir through intranasal delivery. In summary, the promising data observed here signifies the prospective of B1 to enhance the brain targeting of Dolutegravir by intranasal delivery and it could be used as a feasible and practicable strategy for the management of neuroAIDS.

7.
J STEM Outreach ; 5(2)2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-36247713

RESUMEN

The goal of the Rutgers Youth Enjoy Science Program (RUYES) is to increase the diversity of the cancer research workforce. RUYES provides hands-on mentored cancer research experience and curriculum development support to high school science teachers. RUYES also engages high school and undergraduate students from underrepresented backgrounds (URG) in mentored cancer research and professional career development activities. Rutgers Cancer Institute faculty members with active, well-funded research programs and extensive mentoring experience serve as research mentors. In addition, RUYES provides support to participants to develop innovative cancer related outreach activities to connect with families and communities of participants. Teachers and students engage in research and program related activities for a total of 12 weeks per year, for two years. Teachers engage in cancer research for eight weeks each for two consecutive summers (sixteen weeks total). Collaborative partnership with Rutgers Office of STEM Educations supports teachers in developing novel instructional approaches that relate to their research experience. Students have the opportunity to conduct cancer research for ten weeks each for two consecutive summers (twenty weeks total). Students receive co-curricular and professional development support throughout their participation. In addition, teachers and students engage in post-summer program engagement for 4 and 2 weeks, respectively. We recruit program participants from all over New Jersey with special emphasis on school districts with high percentages of students from URG. This report details the components of the RUYES program, outcome evaluation plan, successes and challenges, and lessons learned for others interested in establishing similar programs at their institutions.

8.
Comput Intell Neurosci ; 2022: 8334927, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36172314

RESUMEN

Capital structure is an integral part of the corporate finance that sources the funds to finance growth and operations. Managers always have to maintain value of the firm to be higher than the cost of capital in order to maximize the shareholders wealth. Empirical studies have used sources of finance like debt and equity as variables of capital structure. A choice between debt and equity finance analyzes the firm's ability to perform under the financially constrained environment to attain the sustainable growth. Therefore, it gives rise to a dire need to estimate the cost of capital precisely. We examined the capital structure of top ten market capitalization of the stock markets included in MSCI Emerging index with the use of artificial neural networks, support vector regression, and linear regression in forecasting methods. The capital structure is measured as the proportion of total debt over total equity (Tang et al., 1991). Other financial ratios such as profitability, liquidity, solvent, and turnover ratios were considered as drivers of the capital structure. Applying logistic and hyperbolic tangent activation functions, it was concluded that ANN has a great potential of replacing other traditional forecasting models with the nonstationary data. This research contributes with a new dimension for estimation through different activation functions. There is a possibility of ANN dominance as compared to the other models applied for predictability in financial markets.


Asunto(s)
Administración Financiera , Máquina de Vectores de Soporte , Redes Neurales de la Computación , Solventes
9.
J STEM Outreach ; 5(2)2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37840910

RESUMEN

The National Cancer Institute's (NCI) Youth Enjoy Science Program (YES) funds initiatives to support the cancer research training and career ambitions of middle school through undergraduate students from populations underrepresented in the biomedical sciences. The program has funded 16 institutions nationally as of January 2022. Given the program's focus on increasing diversity within the cancer research workforce, demographic characteristics of YES trainees provide essential information about the populations being served and program effectiveness. Six programs formed an interest group focused on trainee demographics and surveyed all YES grantees about their demographic data practices. Fifteen programs (94%) completed the survey. Survey data were analyzed through descriptive statistics and thematic coding. Findings revealed considerable variability in programs' approach to demographic data, including which demographics were measured, how they were operationalized, and when and how the data were collected. Half of YES programs (53%) could report underrepresented populations in biomedical research among trainees using consistent definitions. Most programs described efforts to improve their demographic data practices; however, challenges remained for the vast majority. In consideration of these findings, we offer recommendations for inclusive demographic data practices to better define and retain underrepresented populations in biomedical sciences.

10.
Gels ; 8(6)2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-35735686

RESUMEN

The clinical efficacy of antiretroviral therapy in NeuroAIDS is primarily limited by the low perfusion of the drug to the brain. The objective of the current investigation was to design and develop an in situ mucoadhesive gel loaded with darunavir to assess the feasibility of brain targeting through the intranasal route. Preliminary batches (F1−F9) were prepared and evaluated for various pharmaceutical characteristics. A full factorial design of the experiment was applied to optimize and assess the effect of two influencing variables (Carbopol 934P (X1) and Poloxamer 407 (X2)) on the response effects (gelation temperature (Y1) and % drug release (Y2) at 8 h). The data demonstrate that both influencing variables affect the response variables significantly (p < 0.05). The optimized formulation (F7) exhibited favorable rheological properties, adequate mucoadhesion, sustained drug release, and greater permeation across the nasal mucosa. An in vitro ciliotoxicity study confirms the nontoxicity of the optimized in situ gel (D7) on the nasal mucosa. An in vivo pharmacokinetic study in rats was performed to assess drug targeting to the brain following the nasal application of the selected in situ gel (D7). Significantly higher (p < 0.0001) Cmax (~4-fold) and AUC0-α (~3.5-fold) values were noticed in the brain after nasal application, as compared to the intravenous route. However, less systemic exposure to darunavir was noticed with nasal therapy, which confirms the low absorption of the drug into the central compartment. Overall, the data here demonstrate that the optimized in situ mucoadhesive nasal gel is effective in targeting darunavir to the brain by the nasal route and could be a viable option for the treatment of NeuroAIDS.

11.
PLoS One ; 15(2): e0228934, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32059042

RESUMEN

Limited empirical data exists on why women and minority students enter Biomedical Career Enrichment Programs (BCEPs) and how program variables-such as duration of research-influence their intention to pursue research careers. This exploratory study reports motivators for participation in BCEPs among women and racial/ethnic minority students-historically underrepresented groups-and the influence of program and personal variables on their research-career intent and self-efficacy beliefs. We studied the program variables of research experience, research duration, and mentor influence; and the personal variables of race, gender, family, and peers. Using the conceptual framework of planned behavior theory and social cognitive career theory, we interviewed students from underrepresented groups participating in BCEPs that offered research experience for short duration (Group A), long duration (Group B), and no research experience (Group C). We utilized Atlas Ti, a qualitative methodological software tool, to analyze the interview responses. Students choosing a BCEP with research experience cited "opportunity to gain experience" and "interest or curiosity in research" as motivators. Duration of research experience had a positive relationship with enhancement in research skills and self-efficacy beliefs, but did not change the initial research-career intent of these BCEP participants. The study revealed an interesting and unexpected theme of "perceived deterrents" to a career in research that included stress of competition (e.g. grants), the instability of projects, and the isolation of scientific research. Importantly, the study findings indicate the need to reform program design and science policies that challenge the current biomedical workforce and dissuade interested students from underrepresented groups from entering the field.


Asunto(s)
Selección de Profesión , Grupos Minoritarios/psicología , Mujeres/psicología , Investigación Biomédica/educación , Investigación Biomédica/tendencias , Conducta de Elección/ética , Toma de Decisiones , Etnicidad/psicología , Femenino , Identidad de Género , Humanos , Intención , Motivación , Proyectos Piloto , Autoeficacia , Factores Sexuales , Estudiantes/psicología , Encuestas y Cuestionarios , Estados Unidos
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