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1.
Chemphyschem ; 25(4): e202300560, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38117002

RESUMO

Very recent experiments on vibrational strong coupling tend to modify chemical reactivity, energy transfer, and many other physical properties of the coupled system. This is achieved without external stimuli and is very sensitive to the vibrational envelope. Water is an excellent vibrational oscillator, which is being used for similar experiments. However, the inhomogeneously broad OH/OD stretching vibrational band make it complicated to characterize the vibro-polaritonic states spectroscopically. In this paper, we performed vibrational strong coupling and mapped the evolution of vibro-polaritonic branches from low to high concentration of H2 O and measured the on-set of strong coupling. The refractive index dispersion is correlated with the cavity tuning experiments. These results are further compared with transfer matrix simulations. Simulated data deviate as noted in the dispersion spectra as the system enters into ultra-strong coupling due to enhanced self-dipolar interactions. Hopfield coefficients calculation shows that even at ±400 cm-1 detuning, the vibro-polaritonic states still possess hybrid characteristics. We systematically varied the concentration of H2 O and mapped the weak, intermediate, and strong coupling regimes to understand the role of inhomogeneously broad OH/OD stretching vibrational band. Our finding may help to better understand the role of H2 O/D2 O strong coupling in the recent polaritonic chemistry experiments.

2.
J Chem Phys ; 152(6): 064704, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32061232

RESUMO

We model the enhancement of near band edge emission from ZnO nanorods using plasmonic metal nanoparticles and compare it with emission enhancement from ZnO with semiconducting quantum dots. Selected CdSe quantum dots with absorption energies close to those of Ag and Au nanoparticles are chosen to construct model systems with ZnO to comprehend the role of ZnO's intrinsic defects and plasmonic excitation in realizing the spectrally selective luminescence enhancement. Excitation wavelength dependent photoluminescence spectra along with theoretical models quantifying the related transitions and plasmonic absorption reveal that a complex mechanism of charge transfer between the ZnO nanorods and metal nanoparticles or quantum dots is essential along with an optimal energy band alignment for realizing emission enhancement. The theoretical model presented also provides a direct method of quantifying the relative transition rate constants associated with various electronic transitions in ZnO and their change upon the incorporation of plasmonic nanoparticles. The results indicate that, while the presence of deep level defect states may facilitate the essential charge transfer process between ZnO and the plasmonic nanoparticles, their presence alone does not guarantee UV emission enhancement and strong plasmonic coupling between the two systems. The results offer clues to designing novel multicomponent systems with coupled plasmonic and charge transfer effects for applications in charge localization, energy harvesting, and luminescence enhancement, especially in electrically triggered nanophotonic applications.

3.
Malar J ; 16(1): 15, 2017 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-28052759

RESUMO

BACKGROUND: Country-level evidence on the impact of malaria control on micro-economic outcomes is vital for mobilizing domestic and donor resources for malaria control. Using routinely available survey data could facilitate this investigation in a cost-efficient way. METHODS: The authors used Malaria Indicator Surveys (MIS) and Living Conditions Monitoring Survey (LCMS) data from 2006 to 2010 for all 72 districts in Zambia to relate malaria control scale-up with household food spending (proxy for household well-being), educational attainment and agricultural production. The authors used two quasi-experimental designs: (1) a generalized propensity score for a continuous treatment variable (defined as coverage from owning insecticide-treated bed nets and/or receipt of indoor residual spraying); and, (2) a district fixed effects model to assess changes in the outcome relative to changes in treatment pre-post scale-up. The unit of analysis was at district level. The authors also conducted simulations post-analysis to assess statistical power. RESULTS: Micro-economic outcomes increased (33% increase in food spending) concurrently with malaria control coverage (62% increase) from 2006 to 2010. Despite using data from all 72 districts, both analytic methods yielded wide confidence intervals that do not conclusively link outcomes and malaria control coverage increases. The authors cannot rule out positive, null or negative effects. The upper bound estimates of the results show that if malaria control coverage increases from 60 to 70%, food spending could increase up to 14%, maize production could increase up to 57%, and years of schooling could increase up to 0.5 years. Simulations indicated that the generalized propensity score model did not have good statistical power. CONCLUSION: While it is technically possible to use routinely available survey data to relate malaria control scale-up and micro-economic outcomes, it is not clear from this analysis that meaningful results can be obtained when survey data are highly aggregated. Researchers in similar settings should assess the feasibility of disaggregating existing survey data. Additionally, large surveys, such as LCMS and MIS, could incorporate data on both malaria coverage and household expenditures, respectively.


Assuntos
Agricultura/economia , Agricultura/métodos , Controle de Doenças Transmissíveis/métodos , Desenvolvimento Econômico , Educação/economia , Malária/prevenção & controle , Condições Sociais/economia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Malária/epidemiologia , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados não Aleatórios como Assunto , Adulto Jovem , Zâmbia/epidemiologia
4.
Sci Rep ; 13(1): 11364, 2023 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-37443329

RESUMO

From August 2020 to June 2021, we assessed the efficacy of SumiShield 50WG (clothianidin), Fludora Fusion 56.25WP-SB (mixture of clothianidin and deltamethrin) and Actellic 300CS (pirimiphos-methyl) in experimental huts when partially sprayed against wild, free-flying populations of Anopheles gambiae s.l. in Tiassalé, Côte d'Ivoire. A one-month baseline period of mosquito collections was conducted to determine mosquito density and resting behavior in unsprayed huts, after which two treatments of partial indoor residual spraying (IRS) were tested: spraying only the top half of walls + ceilings or only the bottom half of walls + ceilings. These were compared to fully sprayed applications using the three IRS insecticide formulations, during twenty nights per month of collection for nine consecutive months. Mortality was assessed at the time of collection, and after a 24 h holding period (Actellic) or up to 120 h (SumiShield and Fludora Fusion). Unsprayed huts were used as a negative control. The efficacy of each partially sprayed treatment of each insecticide was compared monthly to the fully sprayed huts over the study period with a non-inferiority margin set at 10%. The residual efficacy of each insecticide sprayed was also monitored. A total of 2197 Anopheles gambiae s.l. were collected during the baseline and 17,835 during the 9-month period after spraying. During baseline, 42.6% were collected on the bottom half versus 24.3% collected on the top half of the walls, and 33.1% on the ceilings. Over the nine-month post treatment period, 73.5% were collected on the bottom half of the wall, 11.6% collected on the top half and 14.8% on the ceilings. For Actellic, the mean mortality over the nine-month period was 88.5% [87.7, 89.3] for fully sprayed huts, 88.3% [85.1, 91.4] for bottom half + ceiling sprayed walls and 80.8% [74.5, 87.1] for the top half + ceiling sprayed huts. For Fludora Fusion an overall mean mortality of 85.6% [81.5, 89.7] was recorded for fully sprayed huts, 83.7% [82.9, 84.5] for bottom half + ceiling sprayed huts and 81.3% [79.6, 83.0] for the top half + ceiling sprayed huts. For SumiShield, the overall mean mortality was 86.7% [85.3, 88.1] for fully sprayed huts, 85.6% [85.4, 85.8] for the bottom half + ceiling sprayed huts and 76.9% [76.6, 77.3] for the top half + ceiling sprayed huts. For Fludora Fusion, both iterations of partial IRS were non-inferior to full spraying. However, for SumiShield and Actellic, this was true only for the huts with the bottom half + ceiling, reflecting the resting site preference of the local vectors. The results of this study suggest that partial spraying may be a way to reduce the cost of IRS without substantially compromising IRS efficacy.


Assuntos
Anopheles , Inseticidas , Malária , Piretrinas , Animais , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Côte d'Ivoire , Mosquitos Vetores , Malária/prevenção & controle , Resistência a Inseticidas , Piretrinas/farmacologia
5.
Glob Health Sci Pract ; 10(3)2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-36332073

RESUMO

Nepal is one of the first countries to license pharmacists to administer injectable contraceptives, through Nepal CRS Company's (CRS) Sangini private pharmacy network. There are more than 3,400 Sangini pharmacies in Nepal, including in hard-to-reach mountain areas, where these outlets are a key access point to injectables and other short-acting methods for those who lack access through the public sector or prefer the private sector.We compared the performance of Sangini pharmacists in (1) CRS-led technical support visits, when providers were aware of being observed, and (2) mystery client visits, when providers were not aware of being observed, to assess any gaps between pharmacists' knowledge and practices. We also assessed how well Sangini providers counseled on injectables and compared counseling on injectables with counseling for oral contraceptives.We found high levels of adherence to training guidelines on counseling on injectables. However, we identified significant differences between pharmacists' understanding of what they should do and what they actually do in practice, referred to as the know-do gap, in providing privacy, assessing client needs, and determining medical eligibility for hormonal methods. CRS took several steps to narrow the know-do gap through its programming, which may be a useful example for other countries as they expand the role of pharmacies in family planning service provision. Despite highlighting several areas for improvement, the findings show that Sangini providers both know how to and practice appropriate counseling on both injectable and oral contraceptives, suggesting that pharmacists can successfully expand their family planning offerings and equip clients with the information needed to select an appropriate method of their choice.


Assuntos
Farmácias , Feminino , Humanos , Nepal , Serviços de Planejamento Familiar , Farmacêuticos/psicologia , Anticoncepcionais Orais
6.
Sci Rep ; 11(1): 18055, 2021 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-34508114

RESUMO

The scale up of indoor residual spraying (IRS) and insecticide treated nets have contributed significantly to global reductions in malaria prevalence over the last two decades. However, widespread pyrethroid resistance has necessitated the use of new and more expensive insecticides for IRS. Partial IRS with pirimiphos-methyl in experimental huts and houses in a village-wide trial was evaluated against Anopheles gambiae s.l. in northern Ghana. Four different scenarios in which either only the top or bottom half of the walls of experimental huts were sprayed, with or without also spraying the ceiling were compared. Mortality of An. gambiae s.l. on partially sprayed walls was compared with the standard procedures in which all walls and ceiling surfaces are sprayed. A small-scale trial was then conducted to assess the effectiveness, feasibility, and cost of spraying only the upper walls and ceiling as compared to full IRS and no spraying in northern Ghana. Human landing catches were conducted to estimate entomological indices and determine the effectiveness of partial IRS. An established transmission dynamics model was parameterized by an analysis of the experimental hut data and used to predict the epidemiological impact and cost effectiveness of partial IRS for malaria control in northern Ghana. In the experimental huts, partial IRS of the top (IRR 0.89, p = 0.13) or bottom (IRR 0.90, p = 0.15) half of walls and the ceiling was not significantly less effective than full IRS in terms of mosquito mortality. In the village trial, the annual entomological inoculation rate was higher for the unsprayed control (217 infective bites/person/year (ib/p/yr)) compared with the fully and partially sprayed sites, with 28 and 38 ib/p/yr, respectively. The transmission model predicts that the efficacy of partial IRS against all-age prevalence of malaria after six months would be broadly equivalent to a full IRS campaign in which 40% reduction is expected relative to no spray campaign. At scale, partial IRS in northern Ghana would have resulted in a 33% cost savings ($496,426) that would enable spraying of 36,000 additional rooms. These findings suggest that partial IRS is an effective, feasible, and cost saving approach to IRS that could be adopted to sustain and expand implementation of this key malaria control intervention.


Assuntos
Anopheles/efeitos dos fármacos , Inseticidas/administração & dosagem , Controle de Mosquitos/métodos , Compostos Organotiofosforados/administração & dosagem , Partículas e Gotas Aerossolizadas , Animais , Análise Custo-Benefício , Geografia , Gana/epidemiologia , Malária/epidemiologia , Malária/prevenção & controle , Malária/transmissão , Modelos Teóricos , Vigilância em Saúde Pública
7.
Glob Health Sci Pract ; 5(4): 603-616, 2017 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-29242251

RESUMO

BACKGROUND: One of the primary control measures for malaria transmission is indoor residual spraying (IRS). Historically, few women have worked in IRS programs, despite the income-generating potential. Increasing women's roles in IRS requires understanding the barriers to women's participation and implementing measures to address them. The U.S. President's Malaria Initiative (PMI) Africa Indoor Residual Spraying (AIRS) Project is the largest implementer of IRS globally. To address gender inequity in IRS operations, PMI AIRS assessed the barriers to the participation of women and developed and implemented policies to address these barriers. METHODS: The PMI AIRS Project initially identified barriers through a series of informal assessments with key stakeholders. PMI AIRS then implemented a series of gender-guided policies, starting in 2015, in Benin, Ethiopia, Ghana, Mali, Madagascar, Mozambique, Rwanda, Senegal, Zambia, and Zimbabwe. The policies included adapting physical work environments to ensure privacy for women; ensuring the safety of women in the workplace; guaranteeing safety and job security of women during pregnancy; and encouraging qualified women to apply for supervisory positions. The project collected routine programmatic data on staff, spray quality, and spray efficiency; data from 2012 through the end of 2015 were analyzed (up through 1 year after implementation of the gender policies). In addition, PMI AIRS conducted surveys in 2015, 2016, and 2017 before and after the spray campaigns in 4 countries to determine changes in gender norms among spray operators through questions about decision making and agency. RESULTS: The PMI AIRS Project increased women's employment with the program. Specifically, women's employment increased overall from 23% in 2012 to 29% in 2015, with a 2015 range from 16% (Mali) to 40% (Madagascar). Growth among supervisor roles was even stronger, with the percentage of women in supervisory roles increasing from 17% in 2012 to 46% in 2015, with a 2015 range from 9% (Mali) to 50% (Madagascar). While the data showed that in most countries women sprayed fewer houses per day than men in 2015, the differences were not meaningful, ranging from 0.1 to 1.2 households per day. Gender norms shifted toward more egalitarian views in 2 of the 4 countries with survey data. CONCLUSION: Preliminary results suggest the PMI AIRS Project gender policies are increasing the engagement of women in all aspects of spray operations, especially in supervisory roles. Expansion of these policies to all countries implementing IRS and to malaria control implementation more broadly is recommended.


Assuntos
Emprego/estatística & dados numéricos , Inseticidas , Cooperação Internacional , Malária/prevenção & controle , Controle de Mosquitos/métodos , Mulheres Trabalhadoras/estatística & dados numéricos , África , Feminino , Habitação , Humanos , Masculino , Estados Unidos
8.
Contraception ; 95(1): 90-97, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27421767

RESUMO

OBJECTIVES: mHealth, or the use of mobile phones for health, is a promising but largely untested method for increasing family planning knowledge in developing countries. This study estimates the effect of m4RH, an mHealth service in Kenya that provides family planning information via text message, on consumers' knowledge and use of contraception. STUDY DESIGN: We randomly assigned new consumers of the m4RH service to receive either full access or limited access to m4RH. We collected data on outcomes by sending questions directly to consumers via text message. RESULTS: Response rates to the text message surveys ranged from 51.8% to 13.5%. Despite relatively low response rates, response rates were very similar across the full-access and limited-access groups. We find that full access to m4RH increased consumers' scores on a test of contraceptive knowledge by 14% (95% confidence interval: 9.9%-18.2%) compared to a control group with limited access to m4RH. m4RH did not increase consumers' use of contraception, likelihood of discussing family planning with their partners, or likelihood of visiting a clinic to discuss family planning. CONCLUSION: Text messages may increase family planning knowledge but do not, by themselves, lead to behavior change. IMPLICATIONS: Text messages can be an effective method of increasing family planning knowledge but may be insufficient on their own to cause behavior change.


Assuntos
Comportamento Contraceptivo , Serviços de Planejamento Familiar/métodos , Conhecimentos, Atitudes e Prática em Saúde , Telemedicina , Envio de Mensagens de Texto , Adulto , Comunicação , Anticoncepção/métodos , Países em Desenvolvimento , Feminino , Humanos , Quênia , Masculino , Análise de Regressão , Inquéritos e Questionários , Adulto Jovem
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