Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Healthc Qual Res ; 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38616433

RESUMO

BACKGROUND: Improper compliance with antibiotic prophylaxis (AP) in surgery is associated with an increased risk of surgical site infection (SSI), and impacts the efficiency of healthcare. OBJECTIVE: Evaluate the impact of an intervention in compliance with AP in selected surgical procedures and its effect on antibiotic consumption and cost. METHODS: A prospective interventional study was performed in a community hospital from January to December 2022. The baseline period was considered January-April 2022 and the intervention period May-December 2022. All patients who underwent cesarean section, appendectomies, hernia surgery, open reduction and internal fixation (ORIF), abdominoplasty, and cholecystectomy during the study period were selected. The intervention includes staff education, pharmacy interventions, monitoring the quality of prescriptions and feedback, and improved role of anesthesia staff, and department champions. RESULTS: The study involved 192 and 617 surgical procedures in the baseline and intervention periods respectively. The compliance with timing, selection, dose, and discontinuation achieved 100%, 99.2%, and 97.6% from baseline figures of 92.7%, 95.8%, and 81.3%, respectively. The antibiotic consumption was reduced by 55.1% during the intervention with a higher contribution of other antibiotics (94.1% reduction) in comparison with antibiotics as per policy (31.2% reduction). The cost was reduced by 47.2% (antibiotic as per policy 31.9%, other antibiotics 94.2%). CONCLUSION: The implemented strategy was effective in improving the quality of antibiotic prophylaxis with a significant impact in reducing antibiotic consumption and cost.

2.
Phys Rev Lett ; 130(5): 051803, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36800477

RESUMO

The COHERENT Collaboration searched for scalar dark matter particles produced at the Spallation Neutron Source with masses between 1 and 220 MeV/c^{2} using a CsI[Na] scintillation detector sensitive to nuclear recoils above 9 keV_{nr}. No evidence for dark matter is found and we thus place limits on allowed parameter space. With this low-threshold detector, we are sensitive to coherent elastic scattering between dark matter and nuclei. The cross section for this process is orders of magnitude higher than for other processes historically used for accelerator-based direct-detection searches so that our small, 14.6 kg detector significantly improves on past constraints. At peak sensitivity, we reject the flux consistent with the cosmologically observed dark-matter concentration for all coupling constants α_{D}<0.64, assuming a scalar dark-matter particle. We also calculate the sensitivity of future COHERENT detectors to dark-matter signals which will ambitiously test multiple dark-matter spin scenarios.

3.
Phys Rev Lett ; 129(8): 081801, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36053683

RESUMO

We measured the cross section of coherent elastic neutrino-nucleus scattering (CEvNS) using a CsI[Na] scintillating crystal in a high flux of neutrinos produced at the Spallation Neutron Source at Oak Ridge National Laboratory. New data collected before detector decommissioning have more than doubled the dataset since the first observation of CEvNS, achieved with this detector. Systematic uncertainties have also been reduced with an updated quenching model, allowing for improved precision. With these analysis improvements, the COHERENT Collaboration determined the cross section to be (165_{-25}^{+30})×10^{-40} cm^{2}, consistent with the standard model, giving the most precise measurement of CEvNS yet. The timing structure of the neutrino beam has been exploited to compare the CEvNS cross section from scattering of different neutrino flavors. This result places leading constraints on neutrino nonstandard interactions while testing lepton flavor universality and measures the weak mixing angle as sin^{2}θ_{W}=0.220_{-0.026}^{+0.028} at Q^{2}≈(50 MeV)^{2}.

4.
Rev Sci Instrum ; 90(5): 053305, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31153225

RESUMO

The Neutron Scatter Camera (NSC) is a neutron spectrometer and imager that has been developed and improved by the Sandia National Laboratories for several years. Built for special nuclear material searches, the instrument was configured by the design to reconstruct neutron sources within the fission energy range 1-10 MeV. In this work, we present modifications that attempt to extend the NSC sensitivity to neutron energies in the range ∼10-200 MeV and discuss the corresponding consequences for the event processing. We present simulation results that manifest important aspects of the NSC response to those intermediate energy neutrons. The simulation results also evidence that the instrument's spectroscopic capabilities severely deteriorate at those energies, mainly due to the uncertainties in measuring energy, time, and distance between the two neutron scattering interactions. This work is motivated by the need to characterize neutron fluxes at particle accelerators as they may represent important backgrounds for neutrino experiments.

5.
Ther Adv Med Oncol ; 9(10): 637-659, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28974986

RESUMO

Sarcomas are a heterogeneous group of neoplasms of mesenchymal origin. Approximately 80% arise from soft tissue and 20% originate from bone. To date more than 100 sarcoma subtypes have been identified and they vary in molecular characteristics, pathology, clinical presentation and response to treatment. While sarcomas represent <1% of adult cancers, they account for approximately 21% of paediatric malignancies and thus pose some of the greatest risks of mortality and morbidity in children and young adults. Metastases occur in one-third of all patients and approximately 10-20% of sarcomas recur locally. Surgery in combination with preoperative and postoperative therapies is the primary treatment for localized sarcoma tumours and is the most promising curative possibility. Metastasized sarcomas, on the other hand, are treated primarily with single-agent or combination chemotherapy, but this rarely leads to a complete and robust response and often becomes a palliative form of treatment. The heterogeneity of sarcomas results in variable responses to current generalized treatment strategies. In light of this and the lack of curative strategies for metastatic and unresectable sarcomas, there is a need for novel subtype-specific treatment strategies. With the more recent understanding of the molecular mechanisms underlying the pathogenesis of some of these tumours, the treatment of sarcoma subtypes with targeted therapies is a rapidly evolving field. This review discusses the current management of sarcomas as well as promising new therapies that are currently underway in clinical trials.

6.
Addict Biol ; 22(6): 1743-1755, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27549591

RESUMO

Nicotine, a major psychoactive component of tobacco smoke, alters gamma-aminobutyric acid (GABA) modulation of dopamine neurons in the ventral tegmental area (VTA). Changes in structural neuroplasticity can occur in GABAergic parvalbumin (PRV) positive neurons, which are enveloped by structures of the extracellular matrix called perineuronal nets (PNNs). In the current study, rats were trained to self-administer intravenous nicotine (0.03 mg/kg/infusion) for 21 days in 1-hour daily sessions with an incrementing fixed ratio requirement; a control group received saline infusions. At either 45 minutes or 72 hours after the last session, immunofluorescence measurements for PNNs, PRV and c-Fos were conducted. In VTA, nicotine self-administration reduced the number of PRV+ cells surrounded by PNNs at 45 minutes, as well as reducing the intensity of PNNs, suggesting a remodeling of GABA interneurons in this region; the number of PRV+ cells surrounded by PNNs was also reduced at 72 hours. A similar reduction of PNNs occurred in orbitofrontal cortex (OFC) but not in medial prefrontal cortex (prelimbic or infralimbic), 45 minutes after the last session; PNNs were not detected in nucleus accumbens (shell or core). The reduction of PNNs in VTA and OFC was unrelated to c-Fos + cells, as the percent of wisteria floribunda agglutinin + cells co-expressing c-Fos was decreased in OFC but not in VTA. Thus, nicotine self-administration remodeled PNNs surrounding GABA interneurons in VTA and its indirect connections to OFC, suggesting a new possible molecular target where nicotine-induced neuroplasticity takes place. PNN manipulations may prevent or reverse the different stages of tobacco addiction.


Assuntos
Estimulantes Ganglionares/farmacologia , Neurônios/efeitos dos fármacos , Nicotina/farmacologia , Córtex Pré-Frontal/efeitos dos fármacos , Área Tegmentar Ventral/efeitos dos fármacos , Animais , Matriz Extracelular/efeitos dos fármacos , Imunofluorescência , Estimulantes Ganglionares/administração & dosagem , Masculino , Modelos Animais , Plasticidade Neuronal/efeitos dos fármacos , Nicotina/administração & dosagem , Ratos , Ratos Sprague-Dawley , Autoadministração
7.
Dev Biol ; 418(1): 166-178, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27502435

RESUMO

Vertebrate SoxE genes (Sox8, 9, and 10) are key regulators of neural crest cell (NCC) development. These genes arose by duplication from a single SoxE gene in the vertebrate ancestor. Although SoxE paralogs are coexpressed early in NCC development, later, Sox9 is restricted to skeletogenic lineages in the head, and Sox10 to non-skeletogenic NCC in the trunk and head. When this subfunctionalization evolved and its possible role in the evolution of the neural crest are unknown. Sea lampreys are basal vertebrates that also possess three SoxE genes, while only a single SoxE is present in the cephalochordate amphioxus. In order to address the functional divergence of SoxE genes, and to determine if differences in their biochemical functions may be linked to changes in neural crest developmental potential, we examined the ability of lamprey and amphioxus SoxE genes to regulate differentiation of NCC derivatives in zebrafish colourless (cls) mutants lacking expression of sox10. Our findings suggest that the proto-vertebrate SoxE gene possessed both melanogenic and neurogenic capabilities prior to SoxE gene duplication. Following the agnathan-gnathostome split, lamprey SoxE1 and SoxE3 largely lost their melanogenic and/or enteric neurogenic properties, while gnathostome SoxE paralogs have retained functional conservation. We posit that this difference in protein subfunctionalization is a direct consequence of the independent regulation of SoxE paralog expression between the two lineages. Specifically, we propose that the overlapping expression of gnathostome SoxE paralogs in early neural crest largely constrained the function of gnathostome SoxE proteins. In contrast, the largely non-overlapping expression of lamprey SoxE paralogs allowed them to specialize with regard to their DNA-binding and/or protein interaction properties. Restriction of developmental potential among cranial and trunk neural crest in lampreys may be related to constraints on SoxE activity among duplicates, but such specialization does not appear to have occurred in gnathostomes. This highlights an important difference in the evolution of SoxE activity between these two divergent vertebrate lineages and provides insights for understanding how cell fate restriction in different NCC populations may be dependent on subfunctionalization among SoxE duplicates.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Lampreias/embriologia , Anfioxos/embriologia , Crista Neural/embriologia , Fatores de Transcrição SOXE/genética , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/embriologia , Animais , Evolução Biológica , Diferenciação Celular/genética , Duplicação Gênica/genética , Fator de Transcrição Associado à Microftalmia/biossíntese , Crista Neural/citologia , Neurogênese/genética , Proteínas de Peixe-Zebra/biossíntese
8.
Cell Cycle ; 11(20): 3724-30, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22895053

RESUMO

The limitations of revolutionary new mutation-specific inhibitors of BRAF(V600E) include the universal recurrence seen in melanoma patients treated with this novel class of drugs. Recently, our lab showed that simultaneous activation of the Wnt/ß-catenin signaling pathway and targeted inhibition of BRAF(V600E) by PLX4720 synergistically induces apoptosis across a spectrum of BRAF(V600E) melanoma cell lines. As a follow-up to that study, treatment of BRAF-mutant and NRAS-mutant melanoma lines with WNT3A and the MEK inhibitor AZD6244 also induces apoptosis. The susceptibility of BRAF-mutant lines and NRAS-mutant lines to apoptosis correlates with negative regulation of Wnt/ß-catenin signaling by ERK/MAPK signaling and dynamic decreases in abundance of the downstream scaffolding protein, AXIN1. Apoptosis-resistant NRAS-mutant lines can sensitize to AZD6244 by pretreatment with AXIN1 siRNA, similar to what we previously reported in BRAF-mutant cell lines. Taken together, these findings indicate that NRAS-mutant melanoma share with BRAF-mutant melanoma the potential to regulate apoptosis upon MEK inhibition through WNT3A and dynamic regulation of cellular AXIN1. Understanding the cellular context that makes melanoma cells susceptible to this combination treatment will contribute to the study and development of novel therapeutic combinations that may lead to more durable responses.


Assuntos
Antineoplásicos/farmacologia , Benzimidazóis/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Indóis/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Sulfonamidas/farmacologia , Proteína Wnt3A/farmacologia , Apoptose/efeitos dos fármacos , Proteína Axina/antagonistas & inibidores , Proteína Axina/genética , Proteína Axina/metabolismo , Linhagem Celular Tumoral , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Mutação , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , beta Catenina/agonistas , beta Catenina/genética , beta Catenina/metabolismo
9.
Sci Signal ; 5(206): ra3, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22234612

RESUMO

Because the Wnt/ß-catenin signaling pathway is linked to melanoma pathogenesis and to patient survival, we conducted a kinome small interfering RNA (siRNA) screen in melanoma cells to expand our understanding of the kinases that regulate this pathway. We found that BRAF signaling, which is constitutively activated in many melanomas by the BRAF(V600E) mutation, inhibits Wnt/ß-catenin signaling in human melanoma cells. Because inhibitors of BRAF(V600E) show promise in ongoing clinical trials, we investigated whether altering Wnt/ß-catenin signaling might enhance the efficacy of the BRAF(V600E) inhibitor PLX4720. We found that endogenous ß-catenin was required for PLX4720-induced apoptosis of melanoma cells and that activation of Wnt/ß-catenin signaling synergized with PLX4720 to decrease tumor growth in vivo and to increase apoptosis in vitro. This synergistic enhancement of apoptosis correlated with reduced abundance of an endogenous negative regulator of ß-catenin, AXIN1. In support of the hypothesis that AXIN1 is a mediator rather than a marker of apoptosis, siRNA directed against AXIN1 rendered resistant melanoma cell lines susceptible to apoptosis in response to treatment with a BRAF(V600E) inhibitor. Thus, Wnt/ß-catenin signaling and AXIN1 may regulate the efficacy of inhibitors of BRAF(V600E), suggesting that manipulation of the Wnt/ß-catenin pathway could be combined with BRAF inhibitors to treat melanoma.


Assuntos
Apoptose/fisiologia , Proteína Axina/fisiologia , Melanoma/metabolismo , Proteínas Proto-Oncogênicas B-raf/fisiologia , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Humanos , Melanoma/enzimologia , Melanoma/genética , Melanoma/patologia , Mutação
10.
Phys Rev Lett ; 106(13): 131301, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21517370

RESUMO

We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.

11.
Phys Rev Lett ; 101(25): 251301, 2008 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-19113689

RESUMO

A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type of germanium detector to conclusively rule out a standard isothermal galactic halo of weakly interacting massive particles as the explanation for the annual modulation effect leading to the claim. Bounds are similarly imposed on a suggestion that dark pseudoscalars might lead to the effect. We describe the sensitivity to light dark matter particles achievable with our device, in particular, to next-to-minimal supersymmetric model candidates.

12.
J Digit Imaging ; 12(2 Suppl 1): 192-4, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10342209

RESUMO

To fully take advantage of the widespread use of digital imaging systems and to update and eliminate redundant steps involved in medical radiographic publication, we present our experience of processing Digital Imaging and Communications in Medicine (DICOM)-3 digital images from the point of acquisition to the point of publisher-ready radiographic images without intervening hardcopies.


Assuntos
Diagnóstico por Imagem , Microcomputadores , Fotografação , Editoração , Sistemas de Informação em Radiologia , Gráficos por Computador , Sistemas de Gerenciamento de Base de Dados , Humanos , Internet , Imageamento por Ressonância Magnética , Impressão , Software , Tomografia Computadorizada por Raios X
13.
J Hered ; 75(2): 143, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6546940

RESUMO

An improved package of BASIC computer programs designed to facilitate complete analysis of karyotypes is described. The package's many functions include facilities for measurement of chromosomes, analysis of data, pairing of homologues, designation of sex chromosomes and supernumeraries , storage and recall of data, and generation of idiograms and karyograms .


Assuntos
Computadores , Cariotipagem , Software , Cromossomos/ultraestrutura , Cariotipagem/instrumentação , Microcomputadores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...