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1.
Phys Rev Lett ; 131(20): 201802, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-38039466

RESUMO

We search for energetic electron recoil signals induced by boosted dark matter (BDM) from the galactic center using the COSINE-100 array of NaI(Tl) crystal detectors at the Yangyang Underground Laboratory. The signal would be an excess of events with energies above 4 MeV over the well-understood background. Because no excess of events are observed in a 97.7 kg·yr exposure, we set limits on BDM interactions under a variety of hypotheses. Notably, we explored the dark photon parameter space, leading to competitive limits compared to direct dark photon search experiments, particularly for dark photon masses below 4 MeV and considering the invisible decay mode. Furthermore, by comparing our results with a previous BDM search conducted by the Super-Kamionkande experiment, we found that the COSINE-100 detector has advantages in searching for low-mass dark matter. This analysis demonstrates the potential of the COSINE-100 detector to search for MeV electron recoil signals produced by the dark sector particle interactions.

2.
Rev Sci Instrum ; 92(1): 015101, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514205

RESUMO

Broadband seismometers and gravitational wave detectors make use of mechanical resonators with a high quality factor to reduce Brownian noise. At low frequency, Brownian noise is ultimately dominated by internal friction in the suspension, which has a 1/f noise compared with the white noise arising from viscous dissipation. Internal friction is typically modeled as a frequency-dependent loss and can be challenging to measure reliably through experiment. In this work, we present the physics and experimental implementation of electrostatic frequency reduction (EFR) in a mechanical oscillator-a method to measure dissipation as a function of frequency. By applying a high voltage to two parallel capacitor plates, with the center plate being a suspended mass, an electrostatic force is created that acts as a negative stiffness mechanism to reduce the system's resonance frequency. Through EFR, the loss angle can be measured as a function of frequency by measuring amplitude decay response curves for a range of applied voltages. We present experimental measurements of the loss angle for three metal helical extension springs in the nominal frequency range 0.7-2.9 Hz at 0.2 Hz intervals, demonstrating the possibility for fine adjustment of the resonance frequency for loss angle measurements. A quality factor proportional to the resonance frequency squared was measured, an indication that internal friction and other non-viscous dissipation elements, such as electrostatic damping, were the prominent loss mechanisms in our experiments. Finally, we consider the implications of Brownian noise arising from internal friction on a low 1/f noise seismometer.

3.
Phys Rev Lett ; 123(3): 031302, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31386435

RESUMO

We present new constraints on the dark matter-induced annual modulation signal using 1.7 years of COSINE-100 data with a total exposure of 97.7 kg yr. The COSINE-100 experiment, consisting of 106 kg of NaI(Tl) target material, is designed to carry out a model-independent test of DAMA/LIBRA's claim of WIMP discovery by searching for the same annual modulation signal using the same NaI(Tl) target. The crystal data show a 2.7 cpd/kg/keV background rate on average in the 2-6 keV energy region of interest. Using a χ-squared minimization method we observe best fit values for modulation amplitude and phase of 0.0092±0.0067 cpd/kg/keV and 127.2±45.9 d, respectively.

4.
Phys Rev Lett ; 122(13): 131802, 2019 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-31012610

RESUMO

A search for inelastic boosted dark matter (IBDM) using the COSINE-100 detector with 59.5 days of data is presented. This relativistic dark matter is theorized to interact with the target material through inelastic scattering with electrons, creating a heavier state that subsequently produces standard model particles, such as an electron-positron pair. In this study, we search for this electron-positron pair in coincidence with the initially scattered electron as a signature for an IBDM interaction. No excess over the predicted background event rate is observed. Therefore, we present limits on IBDM interactions under various hypotheses, one of which allows us to explore an area of the dark photon parameter space that has not yet been covered by other experiments. This is the first experimental search for IBDM using a terrestrial detector.

5.
Phys Rev E ; 97(2-1): 020101, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29548230

RESUMO

In the modern theory of critical phenomena, the liquid-vapor density diameter in simple fluids is generally expected to deviate from a rectilinear law approaching the critical point. However, by performing precise scannerlike optical measurements of the position of the SF_{6} liquid-vapor meniscus, in an approach much closer to criticality in temperature and density than earlier measurements, no deviation from a rectilinear diameter can be detected. The observed meniscus position from far (10K) to extremely close (1mK) to the critical temperature is analyzed using recent theoretical models to predict the complete scaling consequences of a fluid asymmetry. The temperature dependence of the meniscus position appears consistent with the law of rectilinear diameter. The apparent absence of the critical hook in SF_{6} therefore seemingly rules out the need for the pressure scaling field contribution in the complete scaling theoretical framework in this SF_{6} analysis. More generally, this work suggests a way to clarify the experimental ambiguities in the simple fluids for the near-critical singularities in the density diameter.

6.
Eur Phys J C Part Fields ; 78(6): 490, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30956554

RESUMO

The COSINE-100 dark matter search experiment is an array of NaI(Tl) crystal detectors located in the Yangyang Underground Laboratory (Y2L). To understand measured backgrounds in the NaI(Tl) crystals we have performed Monte Carlo simulations using the Geant4 toolkit and developed background models for each crystal that consider contributions from both internal and external sources, including cosmogenic nuclides. The background models are based on comparisons of measurement data with Monte Carlo simulations that are guided by a campaign of material assays and are used to evaluate backgrounds and identify their sources. The average background level for the six crystals (70 kg total mass) that are studied is 3.5 counts/day/keV/kg in the (2-6) keV energy interval. The dominant contributors in this energy region are found to be 210 Pb and 3 H.

7.
Artigo em Inglês | MEDLINE | ID: mdl-26172640

RESUMO

Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few µK) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.

8.
Mol Plant Microbe Interact ; 25(4): 481-95, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22112214

RESUMO

Agrobacterium tumefaciens-mediated transformation (ATMT) was used to generate an insertional mutant library of the gray mold fungus Botrytis cinerea. From a total of 2,367 transformants, 68 mutants showing significant reduction in virulence on tomato and bean plants were analyzed in detail. As reported for other fungal ATMT libraries, integrations were mostly single copy, occurred preferentially in noncoding (regulatory) regions, and were frequently accompanied by small deletions of the target sequences and loss of parts of the border sequence. Two T-DNA integration events that were found to be linked to virulence were characterized in more detail: a catalytic subunit of a PP2A serine/threonine protein phosphatase (BcPP2Ac) and the SPT3 subunit of a Spt-Ada-Gcn5-acetyltransferase (SAGA-like) transcriptional regulator complex. Gene replacement and silencing approaches revealed that both Bcpp2Ac and SPT3 are crucial for virulence, growth, and differentiation as well as for resistance to H(2)O(2) in B. cinerea.


Assuntos
Botrytis/genética , Botrytis/metabolismo , DNA Bacteriano/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Fatores de Transcrição/metabolismo , Botrytis/patogenicidade , DNA Bacteriano/genética , Regulação Fúngica da Expressão Gênica/fisiologia , Biblioteca Gênica , Inativação Gênica , Mutagênese Insercional , Phaseolus/microbiologia , Fosfoproteínas Fosfatases/genética , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/genética , Virulência
9.
Ophthalmologe ; 108(9): 863-8, 2011 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-21717225

RESUMO

Nanotechnology, the manufacture and use of structures and implements of around a few 100 nm in size, is becoming a key technology of the twenty-first century. An important element for the manufacture of nanoparticles is gold. Gold nanoparticles can be custom made and chemically modified in their size and form. Initial investigations have shown that they are physiologically non-hazardous. A potential application is in neovascular age-related macular degeneration. Gold nanoparticles of suitable dimensions introduced into newly forming blood vessels can be targeted and heated which selectively destroys these blood vessels. This principle has already been demonstrated in cultivated endothelial cells.


Assuntos
Nanotecnologia/métodos , Oftalmologia/métodos , Neovascularização de Coroide/patologia , Neovascularização de Coroide/terapia , Endotélio Vascular/patologia , Ouro , Humanos , Nanopartículas Metálicas , Microscopia Eletrônica , Degeneração Macular Exsudativa/patologia , Degeneração Macular Exsudativa/terapia
10.
Br Poult Sci ; 51(4): 461-87, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20924841

RESUMO

1. Plants and their biologically active chemical constituents, sometimes called secondary metabolites or bioactives, present numerous opportunities for the improvement of livestock production by inclusion in the diet. 2. Many such plant derived materials have well established therapeutic values in man; however, their potential as feed additives in animal production, particularly of poultry, remains largely unexploited. 3. There is increasing evidence indicating that they can be efficient in controlling diseases, and plant bioactives may also influence production parameters such as feed efficiency and product quality. 4. It has been reported that they may even replicate some of the effects of antibiotic growth promoters, which were banned from use in Europe from 2006. 5. This review assesses the status of plant bioactives in poultry production and their mode of action on avian physiology, particularly in the digestive tract.


Assuntos
Ração Animal , Aditivos Alimentares/farmacologia , Plantas/química , Aves Domésticas/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Aditivos Alimentares/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Aves Domésticas/imunologia , Aves Domésticas/microbiologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle
11.
Gesundheitswesen ; 72(10): 700-6, 2010 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-20049687

RESUMO

BACKGROUND: Psycho-oncological care is nowadays an integral part of patient-oriented health care in oncology. Psycho-oncological services are considered in the formulation of guidelines and the existence of such services is a precondition for the certification of organ centres. METHODS: For a status quo analysis of psycho-oncological health-care services for breast cancer patients in inpatient and outpatient care, 101 hospitals (inpatient care) and 124 health-care professionals in outpatient psycho-oncological services were questioned by mail. RESULTS: Psycho-oncological care in the hospital setting is mainly carried out by psychologists and physicians. 2-100% (median: 32.5%) of breast cancer patients receive psycho-oncological treatment. The proportion of psycho-oncological treatment performed by psychologists is higher in bigger hospitals and in hospitals which are part of a breast centre. In outpatient care, psycho-oncological treatment is mainly carried out by psychologists. Most of the interventions are individual therapy sessions (group therapy: median 20%). Most of the participants in the outpatient sector are psychodynamic (43%) or behavioural (23%) therapists, 40% report other therapeutic backgrounds. CONCLUSION: Both the inpatient and the outpatient sectors show a high heterogeneity in psycho-oncological care. The results for the inpatient setting indicate increasing professionalisation and orientation towards certification criteria and treatment guidelines. The heterogeneity in outpatient psycho-oncological care can be interpreted as desirable diversity which allows for the consideration of the varying needs of patients with different diagnoses, disease stages, and treatments.


Assuntos
Assistência Ambulatorial/estatística & dados numéricos , Neoplasias da Mama/psicologia , Hospitalização/estatística & dados numéricos , Comunicação Interdisciplinar , Equipe de Assistência ao Paciente/estatística & dados numéricos , Psicoterapia/estatística & dados numéricos , Currículo , Atenção à Saúde/estatística & dados numéricos , Educação de Pós-Graduação em Medicina , Feminino , Alemanha , Tamanho das Instituições de Saúde , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Mentores , Satisfação do Paciente , Psicoterapia/educação , Psicoterapia/métodos , Qualidade de Vida/psicologia , Inquéritos e Questionários , Revisão da Utilização de Recursos de Saúde/estatística & dados numéricos
12.
Phys Rev Lett ; 99(9): 091301, 2007 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-17930998

RESUMO

The Korea Invisible Mass Search (KIMS) experiment presents new limits on the weakly interacting massive particle (WIMP)-nucleon cross section using data from an exposure of 3409 kg.d taken with low-background CsI(Tl) crystals at the Yangyang Underground Laboratory. The most stringent limit on the spin-dependent interaction for a pure proton case is obtained. The DAMA signal region for both spin-independent and spin-dependent interactions for the WIMP masses greater than 20 GeV/c2 is excluded by the single experiment with crystal scintillators.

13.
Schweiz Arch Tierheilkd ; 147(3): 135-41, 2005 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-15801625

RESUMO

In the last decades phytopharmaceuticals have stabilized their significance in human medicine. The aim of this study was to obtain information about the present situation of phytomedicine in three German-speaking countries. For that purpose questionnaires were sent via internet to 2675 veterinarians in Austria, Germany and Switzerland and the collected 189 answers were statistically evaluated. As shown in this paper, there is an increasing interest in veterinary phytotherapy. Presently three-quarters of the veterinarians are using phytoproducts in clinical practice. Herbal medicinal products are only seldom used in eye and ear infections as well as in endo- and ectoparasitoses but more often in diseases of the liver, joints, kidneys, heart and skin. Generally, phytodrugs are more frequently applied in chronic diseases as well as secondary medication, whereas the time of treatment usually exceeds one month. Basic advantages of medicinal phytoproducts have been shown to be the low side effects and the acceptance of the pet-owners and the only disadventage has been reported to be the lack of information. This study clearly shows the upward trend in using herbal drugs by veterinarians but the results also point to the lack of scientific knowledge about phytotherapeuticals in animal health.


Assuntos
Doenças do Gato/terapia , Doenças do Cão/terapia , Fitoterapia/veterinária , Médicos Veterinários/psicologia , Medicina Veterinária/métodos , Animais , Atitude do Pessoal de Saúde , Áustria , Gatos , Coleta de Dados/métodos , Cães , Alemanha , Conhecimentos, Atitudes e Prática em Saúde , Internet , Fitoterapia/métodos , Inquéritos e Questionários , Suíça
14.
Phys Rev E Stat Nonlin Soft Matter Phys ; 63(5 Pt 2): 055104, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11414949

RESUMO

We present high-resolution measurements of the isothermal susceptibility of pure 3He near the liquid-gas critical point. PVT measurements were performed in the single-phase region over the reduced temperature range 3 x 10(-5)

15.
Emerg Med Clin North Am ; 19(2): 493-510, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11373992

RESUMO

Cocaine use in the United States is widespread, affecting more than 30 million Americans. Although many of these persons do not seek healthcare, the overriding cause for hospitalization is cocaine-associated chest pain. Because only a minority of these patients suffer myocardial injury, it is important to exclude even rarer life-threatening causes for chest pain, such as aortic dissection or pneumothorax. Following that, a thorough knowledge of the pathophysiology and existing literature helps to provide cost-effective care, which focuses resources on those patients most likely to suffer complications. Regardless of the severity of complications, referral to cocaine detoxification programs, counseling, social support, and outpatient follow-up care for modification of cardiac risk factors is a fundamental component of long-term patient care.


Assuntos
Cocaína/efeitos adversos , Inibidores da Captação de Dopamina/efeitos adversos , Infarto do Miocárdio/induzido quimicamente , Isquemia Miocárdica/induzido quimicamente , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/terapia , Dor no Peito/etiologia , Cocaína/farmacologia , Diagnóstico Diferencial , Inibidores da Captação de Dopamina/farmacologia , Serviço Hospitalar de Emergência , Humanos , Infarto do Miocárdio/patologia
17.
Nat Cell Biol ; 2(10): 750-3, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11025667

RESUMO

In plants there are three microtubule arrays involved in cellular morphogenesis that have no equivalent in animal cells. In animals, microtubules are decorated by another class of proteins - the structural MAPS - which serve to stabilize microtubules and assist in their organization. The best-studied members of this class in plants are the MAP-65 proteins that can be purified together with plant microtubules after several cycles of polymerization and depolymerization. Here we identify three similar MAP-65 complementary DNAs representing a small gene family named NtMAP65-1, which encode a new set of proteins, collectively called NtMAP65-1. We show that NtMAP65-1 protein localizes to areas of overlapping microtubules, indicating that it may function in the behaviour of antiparallel microtubules in the mitotic spindle and the cytokinetic phragmoplast.


Assuntos
Nicotiana/genética , Proteínas de Plantas/genética , Plantas Tóxicas , Sequência de Aminoácidos , Compartimento Celular , DNA Complementar/genética , DNA de Plantas/genética , Imunofluorescência , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Dados de Sequência Molecular , Proteínas de Plantas/isolamento & purificação , Análise de Sequência , Homologia de Sequência de Aminoácidos
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