528 research outputs found
Non-minimally coupled scalar fields and isolated horizons
The isolated horizon framework is extended to include non-minimally coupled
scalar fields. As expected from the analysis based on Killing horizons, entropy
is no longer given just by (a quarter of) the horizon area but also depends on
the scalar field. In a subsequent paper these results will serve as a point of
departure for a statistical mechanical derivation of entropy using quantum
geometry.Comment: 14 pages, 1 figure, revtex4. References and minor clarifications
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Effect of ultra high temperature (UHT) treatment on coffee brew stability
In this work, the influence of an Ultra High Temperature (UHT) treatment on chemical and sensory composition of Arabica coffee brews for a longer shelf-life has been studied. A temperature of 120 degrees C for 2 s allows to obtain a microbiologically safe coffee brew, good valued from the sensory point of view. The behavior of the UHT vs non UHT treated coffee brew was followed throughout 120 days of storage at 4 degrees C. The UHT treatment keeps the typical acidity of the brews longer, delaying and softening the pH decrease and the development of sourness, which is one of the main causes for the rejection of stored coffee brews. The UHT treatment hardly affects the concentrations of caffeine and trigonelline, and of some phenolic compounds such as 5-caffeoylquinic (5-CQA), caffeic or ferulic acids. Sixteen key odorants and staling volatiles were analyzed by HS-GC-MS and lower changes were observed in the UHT treated coffee brew throughout storage. Higher DPPH center dot scavenging activity was observed in the UHT treated coffee brew from days 60 to 120. In conclusion, the application of an UHT treatment is proposed to extend the shelf-life (up to 60 days) of stored coffee brews
Epidemiology of varicella in spain pre-and post-vaccination periods
BACKGROUND: Varicella virus can cause two different diseases: chickenpox and herpes zoster. In 2005 varicella vaccine has been introduced in the Spanish national vaccination schedule for 10-14 years old non-immune people, in order to reduce the severity of the disease. In 2007 a new surveillance protocol with aggregate data for chickenpox and herpes zoster was approved in order to detect any change in age distribution, severity and complications of the chickenpox and herpes zoster cases. The aim of this study is to know the burden of diseases (in the last ten years). METHODS: Number of cases, hospitalization and incidence for chickenpox and herpes zoster were study for two periods 1997-2003 and 2005-2007. Analysis for 1996-2007 fatal cases was done too. We decided to remove year 2004 because the extremely high chickenpox incidence registered. SOURCES OF DATA: RENAVE (Spanish Surveillance Network), Spanish hospital surveillance system (CMBD), and mortality registries. RESULTS: Chickenpox incidence decreased since 2005, but an increasing trend was detected in hospitalisation with an average of 1,311 hospitalizations every year. For the 32%-36% of hospitalized cases, the main diagnosis was not chickenpox. 4-14 deaths per year have been detected; 80% of them were older than 14 years. Annual rate of herpes zoster hospitalization was 2.5 per 100,000 inhabitants, similar in both sexes. Case fatality rate per year was 0.31 per million inhabitants. No significant changes were detected in age and sex in complicated cases between the two periods. 88% of chickenpox cases were younger than 15 years old and 64% of herpes zoster older than 50 years in 2007. CONCLUSIONS: Chickenpox has been decreasing during 2005-2007 in Spain. The impact of vaccination is difficult to asses, because of a peak registered in 2004 but also because the lack of vaccination coverage information for this period and the case-data information is available only for the last year. Fundamento: El virus varicela zoster puede causar dos enfermedades, la varicela y el herpes zóster. La vacuna frente a la varicela se incorporó en España en 2005 para personas susceptibles de entre 10 y 14 años. En 2007 se aprobó una propuesta de vigilancia de la varicela y herpes zóster que permitiera detectar posibles cambios en los patrones de distribución por edad, en la gravedad y complicaciones. El objetivo de este trabajo es conocer la carga de enfermedad por varicela antes y después de la vacunación.
Método: Se analizan los datos agregados (casos e incidencia) de varicela y herpes zóster en España en el sistema CMBD para 1997-2003 y 2005-2007, así como la mortalidad por esta enfermedad a nivel nacional para e período 1999-2006.
Resultados: El 88,1% de los casos de varicela se da en personas menores de 15 años. En el CMBD se registró un promedio anual de 1.311 ingresos. No se observaron cambios significativos en la distribución por edad, sexo ni complicaciones durante los ingresos en ninguno de los períodos estudiados. El 32-36% anual ingresó por un motivo diferente a varicela. La mortalidad osciló entre 4 y 14 individuos/año, el 80% mayores de 14 años. El 64% de los casos notificados de herpes zóster fueron mayores de 50 años. La tasa media anual de ingresos por fue de 2,5 por 100.000 habitantes sin diferencias por sexo. La tasa media anual de defunciones fue 0,31 por millón de habitantes.
Conclusiones: En España la varicela tuvo una disminución generalizada durante 2005-2007, pero es difícil valorar el impacto de la vacunación por la falta de cifras de cobertura vacunal y porque este período coincide con el inmediato a la última onda epidémica, cuyo máximo se registró en 2004
Superplastic deformation of directionally solidified nanofibrillar Al2O3-Y3Al5O12-ZrO2 eutectics
Nanofibrillar Al2O3–Y3Al5O12–ZrO2 eutectic rods were manufactured by directional solidification from the melt at high growth rates in an inert atmosphere using the laser-heated floating zone method. Under conditions of cooperative growth, the ternary eutectic presented a homogeneous microstructure, formed by bundles of single-crystal c-oriented Al2O3 and Y3Al5O12 (YAG) whiskers of ≈100 nm in width with smaller Y2O3-doped ZrO2 (YSZ) whiskers between them. Owing to the anisotropic fibrillar microstructure, Al2O3–YAG–YSZ ternary eutectics present high strength and toughness at ambient temperature while they exhibit superplastic behavior at 1600 K and above. Careful examination of the deformed samples by transmission electron microscopy did not show any evidence of dislocation activity and superplastic deformation was attributed to mass-transport by diffusion within the nanometric domains. This combination of high strength and toughness at ambient temperature together with the ability to support large deformations without failure above 1600 K is unique and shows a large potential to develop new structural materials for very high temperature structural applications
Autophagy and Apoptosis Have a Role in the Survival or Death of Stallion Spermatozoa during Conservation in Refrigeration
Apoptosis has been recognized as a cause of sperm death during cryopreservation and a cause of infertility in humans, however there is no data on its role in sperm death during conservation in refrigeration; autophagy has not been described to date in mature sperm. We investigated the role of apoptosis and autophagy during cooled storage of stallion spermatozoa. Samples from seven stallions were split; half of the ejaculate was processed by single layer centrifugation, while the other half was extended unprocessed, and stored at 5°C for five days. During the time of storage, sperm motility (CASA, daily) and membrane integrity (flow cytometry, daily) were evaluated. Apoptosis was evaluated on days 1, 3 and 5 (active caspase 3, increase in membrane permeability, phosphatidylserine translocation and mitochondrial membrane potential) using flow cytometry. Furthermore, LC3B processing was investigated by western blotting at the beginning and at the end of the period of storage. The decrease in sperm quality over the period of storage was to a large extent due to apoptosis; single layer centrifugation selected non-apoptotic spermatozoa, but there were no differences in sperm motility between selected and unselected sperm. A high percentage of spermatozoa showed active caspase 3 upon ejaculation, and during the period of storage there was an increase of apoptotic spermatozoa but no changes in the percentage of live sperm, revealed by the SYBR-14/PI assay, were observed. LC3B was differentially processed in sperm after single layer centrifugation compared with native sperm. In processed sperm more LC3B-II was present than in non-processed samples; furthermore, in non-processed sperm there was an increase in LC3B-II after five days of cooled storage. These results indicate that apoptosis plays a major role in the sperm death during storage in refrigeration and that autophagy plays a role in the survival of spermatozoa representing a new pro-survival mechanism in spermatozoa not previously described
The Surgical Infection Society revised guidelines on the management of intra-abdominal infection
Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations.
Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council.
Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included.
Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline
Ferromagnetic/superconducting proximity effect in La0.7Ca0.3MnO3 / YBa2Cu3O7 superlattices
We study the interplay between magnetism and superconductivity in high
quality YBa2Cu3O7 (YBCO) / La0.7Ca0.3MnO3(LCMO)superlattices. We find evidence
for the YBCO superconductivity depression in presence of the LCMO layers. We
show that due to its short coherence length superconductivity survives in the
YBCO down to much smaller thickness in presence of the magnetic layer than in
low Tc superconductors. We also find that for a fixed thickness of the
superconducting layer, superconductivity is depressed over a thickness interval
of the magnetic layer in the 100 nm range. This is a much longer length scale
than that predicted by the theory of ferromagnetic/superconducting proximity
effect.Comment: 10 pages + 5 figures, submitted to Phys. Rev.
Sirtuin-2, NAD-Dependent Deacetylase, is a new potential therapeutic target for HIV-1 infection and HIV-related neurological dysfunction
The implementation and access to combined antiretroviral treatment (cART) have dramatically improved the quality of life of people living with HIV (PLWH). However, some comorbidities, such as neurological disorders associated with HIV infection still represent a serious clinical challenge. Soluble factors in plasma that are associated with control of HIV replication and neurological dysfunction could serve as early biomarkers and as new therapeutic targets for this comorbidity. We used a customized antibody array for determination of blood plasma factors in 40 untreated PLWH with different levels of viremia and found sirtuin-2 (SIRT2), an NAD-dependent deacetylase, to be strongly associated with elevated viral loads and HIV provirus levels, as well as with markers of neurological damage (a-synuclein [SNCA], brain-derived neurotrophic factor [BDNF], microtubule-associated protein tau [MAPT], and neurofilament light protein [NFL]). Also, longitudinal analysis in HIV-infected individuals with immediate (n = 9) or delayed initiation (n = 10) of cART revealed that after 1 year on cART, SIRT2 plasma levels differed between both groups and correlated inversely with brain orbitofrontal cortex involution. Furthermore, targeting SIRT2 with specific small-molecule inhibitors in in vitro systems using J-LAT A2 and primary glial cells led to diminished HIV replication and virus reactivation from latency. Our data thus identify SIRT2 as a novel biomarker of uncontrolled HIV infection, with potential impact on neurological dysfunction and offers a new therapeutic target for HIV treatment and cure. IMPORTANCE Neurocognitive disorders are frequently reported in people living with HIV (PLWH) even with the introduction of combined antiretroviral treatment (cART). To identify biomarkers and potential therapeutic tools to target HIV infection in peripheral blood and in the central nervous system (CNS), plasma proteomics were applied in untreated chronic HIV-infected individuals with different levels of virus control. High plasma levels of sirtuin-2 (SIRT2), an NAD+ deacetylase, were detected in uncontrolled HIV infection and were strongly associated with plasma viral load and proviral levels. In parallel, SIRT2 levels in the peripheral blood and CNS were associated with markers of neurological damage and brain involution and were more pronounced in individuals who initiated cART later in infection. In vitro infection experiments using specific SIRT2 inhibitors suggest that specific targeting of SIRT2 could offer new therapeutic treatment options for HIV infections and their associated neurological dysfunction
Nivolumab and sunitinib combination in advanced soft tissue sarcomas : A multicenter, single-arm, phase Ib/II trial
Sarcomas exhibit low expression of factors related to immune response, which could explain the modest activity of PD-1 inhibitors. A potential strategy to convert a cold into an inflamed microenvironment lies on a combination therapy. As tumor angiogenesis promotes immunosuppression, we designed a phase Ib/II trial to test the double inhibition of angiogenesis (sunitinib) and PD-1/PD-L1 axis (nivolumab). This single-arm, phase Ib/II trial enrolled adult patients with selected subtypes of sarcoma. Phase Ib established two dose levels: level 0 with sunitinib 37.5 mg daily from day 1, plus nivolumab 3 mg/kg intravenously on day 15, and then every 2 weeks; and level-1 with sunitinib 37.5 mg on the first 14 days (induction) and then 25 mg per day plus nivolumab on the same schedule. The primary endpoint was to determine the recommended dose for phase II (phase I) and the 6-month progression-free survival rate, according to Response Evaluation Criteria in Solid Tumors 1.1 (phase II). From May 2017 to April 2019, 68 patients were enrolled: 16 in phase Ib and 52 in phase II. The recommended dose of sunitinib for phase II was 37.5 mg as induction and then 25 mg in combination with nivolumab. After a median follow-up of 17 months (4-26), the 6-month progression-free survival rate was 48% (95% CI 41% to 55%). The most common grade 3-4 adverse events included transaminitis (17.3%) and neutropenia (11.5%). Sunitinib plus nivolumab is an active scheme with manageable toxicity in the treatment of selected patients with advanced soft tissue sarcoma, with almost half of patients free of progression at 6 months
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