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1.
Phys Rev Lett ; 132(4): 041001, 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335333

RESUMO

With excellent energy resolution and ultralow-level radiogenic backgrounds, the high-purity germanium detectors in the Majorana Demonstrator enable searches for several classes of exotic dark matter (DM) models. In this work, we report new experimental limits on keV-scale sterile neutrino DM via the transition magnetic moment from conversion to active neutrinos ν_{s}→ν_{a}. We report new limits on fermionic dark matter absorption (χ+A→ν+A) and sub-GeV DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), and new exclusion limits for bosonic dark matter (axionlike particles and dark photons). These searches utilize the (1-100)-keV low-energy region of a 37.5-kg y exposure collected by the Demonstrator between May 2016 and November 2019 using a set of ^{76}Ge-enriched detectors whose surface exposure time was carefully controlled, resulting in extremely low levels of cosmogenic activation.

2.
Phys Rev Lett ; 130(6): 062501, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36827565

RESUMO

The Majorana Demonstrator searched for neutrinoless double-ß decay (0νßß) of ^{76}Ge using modular arrays of high-purity Ge detectors operated in vacuum cryostats in a low-background shield. The arrays operated with up to 40.4 kg of detectors (27.2 kg enriched to ∼88% in ^{76}Ge). From these measurements, the Demonstrator has accumulated 64.5 kg yr of enriched active exposure. With a world-leading energy resolution of 2.52 keV FWHM at the 2039 keV Q_{ßß} (0.12%), we set a half-life limit of 0νßß in ^{76}Ge at T_{1/2}>8.3×10^{25} yr (90% C.L.). This provides a range of upper limits on m_{ßß} of (113-269) meV (90% C.L.), depending on the choice of nuclear matrix elements.

3.
Phys Rev Lett ; 131(15): 152501, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37897780

RESUMO

^{180m}Ta is a rare nuclear isomer whose decay has never been observed. Its remarkably long lifetime surpasses the half-lives of all other known ß and electron capture decays due to the large K-spin differences and small energy differences between the isomeric and lower-energy states. Detecting its decay presents a significant experimental challenge but could shed light on neutrino-induced nucleosynthesis mechanisms, the nature of dark matter, and K-spin violation. For this study, we repurposed the Majorana Demonstrator, an experimental search for the neutrinoless double-beta decay of ^{76}Ge using an array of high-purity germanium detectors, to search for the decay of ^{180m}Ta. More than 17 kg, the largest amount of tantalum metal ever used for such a search, was installed within the ultralow-background detector array. In this Letter, we present results from the first year of Ta data taking and provide an updated limit for the ^{180m}Ta half-life on the different decay channels. With new limits up to 1.5×10^{19} yr, we improved existing limits by 1-2 orders of magnitude which are the most sensitive searches for a single ß and electron capture decay ever achieved. Over all channels, the decay can be excluded for T_{1/2}<0.29×10^{18} yr.

5.
Kathmandu Univ Med J (KUMJ) ; 21(82): 180-184, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38628012

RESUMO

Background Maternal Health is a priority program of Nepal. The low utilization of maternal health services is one of the major contributing factors for high maternal morbidity and mortality in developing countries like Nepal. Objective To explore various maternal health services utilized by women and identify various factors affecting the utilization of maternal health services in Panchkhal Municipality. Method A descriptive cross-sectional study was conducted among 355 reproductive-age women who have given birth in the last 2 years in Panchkhal Municipality. The data collection period was from May to July 2020. A convenient sampling method was used to select the study population. The data analysis was done by using Statistical Package for Social Sciences (version 20.0). Variables were defined by the frequency in numbers and percentages. Result The findings from the study showed that the coverage of the antenatal care (ANC) visit was 77% and among them, 25.6% visited at least 4 antenatal care visits as recommended by the government of Nepal. Out of 355 respondents, 52.4% were delivered in the health institution, and only 20% visited postnatal care after the delivery. Among various factors, lack of treatment facilities and health facilities at a far distance were the most common factors for the underutilization of maternal health services. Conclusion The coverage of maternal health services is still low despite free maternal health services with an incentive scheme. A further detailed investigation is required to find the real scenario of the Panchkhal municipality to under-utilization of maternal health services.


Assuntos
Serviços de Saúde Materna , Feminino , Gravidez , Humanos , Pré-Escolar , Nepal , Estudos Transversais , Cuidado Pré-Natal , Saúde Materna , Fatores Socioeconômicos
6.
Phys Rev Lett ; 129(8): 080401, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36053678

RESUMO

The Majorana Demonstrator neutrinoless double-beta decay experiment comprises a 44 kg (30 kg enriched in ^{76}Ge) array of p-type, point-contact germanium detectors. With its unprecedented energy resolution and ultralow backgrounds, Majorana also searches for rare event signatures from beyond standard model physics in the low energy region below 100 keV. In this Letter, we test the continuous spontaneous localization (CSL) model, one of the mathematically well-motivated wave function collapse models aimed at solving the long-standing unresolved quantum mechanical measurement problem. While the CSL predicts the existence of a detectable radiation signature in the x-ray domain, we find no evidence of such radiation in the 19-100 keV range in a 37.5 kg-y enriched germanium exposure collected between December 31, 2015, and November 27, 2019, with the Demonstrator. We explored both the non-mass-proportional (n-m-p) and the mass-proportional (m-p) versions of the CSL with two different assumptions: that only the quasifree electrons can emit the x-ray radiation and that the nucleus can coherently emit an amplified radiation. In all cases, we set the most stringent upper limit to date for the white CSL model on the collapse rate, λ, providing a factor of 40-100 improvement in sensitivity over comparable searches. Our limit is the most stringent for large parts of the allowed parameter space. If the result is interpreted in terms of the Diòsi-Penrose gravitational wave function collapse model, the lower bound with a 95% confidence level is almost an order of magnitude improvement over the previous best limit.

7.
Phys Rev Lett ; 129(8): 081803, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36053699

RESUMO

Axions were originally proposed to explain the strong-CP problem in QCD. Through axion-photon coupling, the Sun could be a major source of axions, which could be measured in solid state detection experiments with enhancements due to coherent Primakoff-Bragg scattering. The Majorana Demonstrator experiment has searched for solar axions with a set of ^{76}Ge-enriched high purity germanium detectors using a 33 kg-yr exposure collected between January, 2017 and November, 2019. A temporal-energy analysis gives a new limit on the axion-photon coupling as g_{aγ}<1.45×10^{-9} GeV^{-1} (95% confidence level) for axions with mass up to 100 eV/c^{2}. This improves laboratory-based limits between about 1 eV/c^{2} and 100 eV/c^{2}.

8.
Kathmandu Univ Med J (KUMJ) ; 19(73): 41-46, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34812156

RESUMO

Background Cement factory workers are exposed to cement dust at workplace. It leads to a greater prevalence of chronic respiratory signs and symptoms. Objective To identify the prevalence of Work-related respiratory symptoms, its association with various risk factors, and to assess the outcomes like hospitalization and sickness absenteeism. Method Cross-sectional study was conducted in the Argakhanchi Cement factory among 190 workers with minimum work experience of 1 year. Census method was used for data collection. To assess the respiratory symptoms, sputum samples were collected; smears prepared by pick and smear method, and later stained by Leishman and pap stain. Smears devoid of alveolar macrophages were considered unsatisfactory for evaluation. Result The mean age of respondents with standard deviation was 35.56±11.45 years. The prevalence of Work-related respiratory symptoms was 31.6%. Age, no. of years worked, working in the raw materials department, burner and clinker department, cleaning department and wearing mask were the significant risk factors. On cytological analysis of the sputum sample, mild inflammatory cell noticed in 71.6%, moderate inflammation in 23.7%, and dense inflammation in 4.2%. Fungal spores were seen in 3.7%, fungal pseudohyphae in 0.5%, and bacterial colonies in 27% of the sputum samples. Out of 190 participants, 8(4.2%) of them had to be hospitalized and 17(8.9%) were on sick leave due to respiratory symptoms. Conclusion Pre-employment and periodic medical examination, frequent work shift, training on occupational health and safety, use of appropriate personnel protective equipment is recommended to reduce respiratory symptoms.


Assuntos
Doenças Profissionais , Exposição Ocupacional , Adulto , Estudos Transversais , Poeira/análise , Humanos , Pessoa de Meia-Idade , Nepal/epidemiologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Adulto Jovem
9.
Kathmandu Univ Med J (KUMJ) ; 5(2): 173-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18604014

RESUMO

OBJECTIVES: To examine the differences in maternal and perinatal outcome among booked and unbooked pregnant women and their perception for underutilization of services targeted for them. METHODS: Two thousand two hundred and twenty eight pregnant women, booked and unbooked, attending emergency obstetrics care during Jan.-Dec. 2005, were included in the study; Investigators followed cases till discharge. RESULTS: Tendency for mothers to be booked was found to be significantly associated with age. Booked and unbooked mothers differed by distance to the hospital and parity. There was difference between the periods of gestation at which they presented to the hospital among both the groups (p<0.0001). Nearly eighty percent (81.4%) of unbooked mothers did not know the period of gestation. Most of these women conceived during lactational or depo provera-induced amenorrhea. The maternal mortality rate for unbooked mothers was 16 out of 1056 and none among the booked. Perinatal mortality is 3 times less in booked mothers. Higher perinatal mortalities are associated with unbooked mothers and had a higher proportion of maternal intensive care unit admissions and perinatal deaths compared with the booked group. Focus group discussion revealed that the reasons for underutilizations of services are; Distance, cost, disempowerment of women and attitudes of hospital personnel. CONCLUSION: The opportunities to enhance utilizations are based on distance, cost and client friendly environment of hospital personnel. It has been observed, building teaching hospitals alone, will not have much impact to maternal and perinatal outcome, unless peripheral health institutions are equipped with facilities and service provisions.


Assuntos
Área Programática de Saúde , Serviços de Saúde Materna/estatística & dados numéricos , Resultado da Gravidez , Adulto , Fatores Etários , Atitude do Pessoal de Saúde , Serviço Hospitalar de Emergência , Feminino , Humanos , Mortalidade Infantil , Recém-Nascido , Unidades de Terapia Intensiva/estatística & dados numéricos , Mortalidade Materna , Nepal , Poder Psicológico , Gravidez , Direitos da Mulher
10.
Int J Pharm Pharm Sci ; 2020 Jul; 12(7): 26-31
Artigo | IMSEAR | ID: sea-206121

RESUMO

Objective: Because of adverse side effects, caused by NSAIDs, tolerance, and dependence induced by opiates, the use of these analgesic agents has not been successful in all cases. Therefore, alternative analgesic drugs from plant sources are the new target now days. The objective of this study was to evaluate the analgesic activity of ethanolic extracts of stem barks and leaves of Ficus religiosa. Methods: The analgesic activity of ethanolic extract of stem barks and leaves was evaluated in the Swiss albino mice model using acetic acid-induced writing response and Eddy’s hot plate method. Analgesic activity was demonstrated with the percentage inhibition of acetic acid induced writings and the percentage increased in latency time of paw licking. The potency of test extracts was compared with standard drug, Diclofenac. Results: Ethanolic extract of leaves and bark of F. religiosa showed potential analgesic activity from both methods. From Eddy’s hot plate model, it was observed that the percentage of increased latency time at 90 min by ethanolic extract of leaves and stem bark was found to be 70.81 % (8.54 min) and 70.78 % (8.53 min) respectively at a dose of 400 mg/kg. Both of these results are statistically significant (p<0.05) as compared to the test group. Furthermore, both of these extracts showed the dose-dependent and time-dependent increased in latency time and these results are compared to that of standard drug Diclofenac. Similarly, ethanolic extract of leaves and stem at 400 mg/kg significantly inhibited the number of writhings induced by acetic acid. The percentage inhibition of writhings by ethanolic extract of leaves at a dose of 400 mg/kg was 68.47 % which was similar to that of standard drug Diclofenac (68.47 %). However, ethanolic extract of bark showed relatively lower percentage inhibition (60.79 %) as compared to leaf extract and standard, but the result was significant as compared to that of the test group (p<0.05). Conclusion: Ethanolic extracts of F. religiosa stem bark and leaf possess both central and peripheral analgesic properties and these effects may be beneficial for the management of pain.

11.
J Nepal Health Res Counc ; 9(1): 86-8, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22929722

RESUMO

It has become a rising trend in Nepal to conduct health camps. This article tries to give an overview about the direction to which this aspect of community based service is going to and also points out a few pros and cons related to this. A couple of issues has also been raised like; ethical issues, lack of governing bodies and a lack of national policy, unavailability of data upon health camps and so forth. Above all, this article tries to clarify the importance of conducting health camps in a country like ours and if properly conducted this has a balanced benefit to all.


Assuntos
Serviços de Saúde Comunitária/organização & administração , Encaminhamento e Consulta , Relações Comunidade-Instituição , Nepal
12.
Artigo em Inglês | IMSEAR | ID: sea-46526

RESUMO

OBJECTIVES: To examine the differences in maternal and perinatal outcome among booked and unbooked pregnant women and their perception for underutilization of services targeted for them. METHODS: Two thousand two hundred and twenty eight pregnant women, booked and unbooked, attending emergency obstetrics care during Jan.-Dec. 2005, were included in the study; Investigators followed cases till discharge. RESULTS: Tendency for mothers to be booked was found to be significantly associated with age. Booked and unbooked mothers differed by distance to the hospital and parity. There was difference between the periods of gestation at which they presented to the hospital among both the groups (p<0.0001). Nearly eighty percent (81.4%) of unbooked mothers did not know the period of gestation. Most of these women conceived during lactational or depo provera-induced amenorrhea. The maternal mortality rate for unbooked mothers was 16 out of 1056 and none among the booked. Perinatal mortality is 3 times less in booked mothers. Higher perinatal mortalities are associated with unbooked mothers and had a higher proportion of maternal intensive care unit admissions and perinatal deaths compared with the booked group. Focus group discussion revealed that the reasons for underutilizations of services are; Distance, cost, disempowerment of women and attitudes of hospital personnel. CONCLUSION: The opportunities to enhance utilizations are based on distance, cost and client friendly environment of hospital personnel. It has been observed, building teaching hospitals alone, will not have much impact to maternal and perinatal outcome, unless peripheral health institutions are equipped with facilities and service provisions.

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