1,331 research outputs found
Dynamics of Sleep-Wake Transitions During Sleep
We study the dynamics of the awakening during the night for healthy subjects
and find that the wake and the sleep periods exhibit completely different
behavior: the durations of wake periods are characterized by a scale-free
power-law distribution, while the durations of sleep periods have an
exponential distribution with a characteristic time scale. We find that the
characteristic time scale of sleep periods changes throughout the night. In
contrast, there is no measurable variation in the power-law behavior for the
durations of wake periods. We develop a stochastic model which agrees with the
data and suggests that the difference in the dynamics of sleep and wake states
arises from the constraints on the number of microstates in the sleep-wake
system.Comment: Final form with some small corrections. To be published in
Europhysics Letters, vol. 57, issue no. 5, 1 March 2002, pp. 625-63
TLR4 expression in ex-Lichenoid lesions—oral squamous cell carcinomas and its surrounding epithelium: the role of tumor inflammatory microenvironment
Abstract: Toll-like receptors (TLRs) regulate innate and adaptive immune responses. Moreover, TLRs can induce a pro-survival and pro-proliferation response in tumor cells. This study aims to investigate the expression of TLR4 in the epithelium surrounding oral squamous cell carcinomas (OSCC) in relation to its inflammatory microenvironment. This study included 150 human samples: 30 normal oral control (NOC), 38 non-lichenoid epithelium surrounding OSCC (NLE-OSCC), 28 lichenoid epithelium surrounding OSCC (LE-OSCC), 30 OSCC ex-non oral lichenoid lesion (OSCC Ex-NOLL), and 24 OSCC ex-oral lichenoid lesion (OSCC Ex-OLL). TLR4 expression was investigated by immuno histochemistry and the percentage of positive cells was quantified. In addition, a semiquantitative analysis of staining intensity was performed. Immunohistochemical analysis revealed that TLR4 is strongly upregulated in LE-OSCC as compared to normal control epithelium and NLE-OSCC. TLR4 expression was associated with the inflammatory environment, since the percentage of positive cells increases from NOC and NLE-OSCC to LE-OSCC, reaching the highest value in OSCC Ex–OLL. TLR4 was detected in the basal third of the epithelium in NLE-OSCC, while in LE-OSCC, TLR4 expression reached the intermediate layer. These results demonstrated that an inflammatory microenvironment can upregulate TLR4, which may boost tumor development
Drug susceptibility profiles of pulmonary Mycobacterium tuberculosis isolates from patients in informal urban settlements in Nairobi, Kenya
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
An ESPRESSO view of HD 189733 system. Broadband transmission spectrum, differential rotation, and system architecture
The development of state-of-the-art spectrographs has ushered in a new era in
the detection and characterization of exoplanetary systems. Our objective is to
utilize the high-resolution and precision capabilities of the ESPRESSO
instrument to detect and measure the broad-band transmission spectrum of HD
189733b's atmosphere. Additionally, we aim to employ an improved
Rossiter-McLaughlin model to derive properties related to the velocity fields
of the stellar surface and to constrain the orbital architecture.
Our results demonstrate a high degree of precision in fitting the observed
radial velocities during transit using the improved modeling of the
Rossiter-McLaughlin effect. We tentatively detect the effect of differential
rotation with a confidence level of when considering a rotation
period within the photometric literature values, and for a broader
range of rotation periods. For the former, the amplitude of differential
rotation ratio suggests an equatorial rotation period of days
and a polar period of . The addition of differential rotation breaks
the latitudinal symmetry, enabling us to measure the true spin-orbit angle and the stellar inclination axis angle . Moreover, we determine a
sub-solar amplitude of the convective blueshift velocity
ms, which falls within the expected range for
a K-dwarf host star and is compatible with both runs.
Finally, we successfully retrieved the transmission spectrum of HD 189733b
from the high-resolution ESPRESSO data. We observe a significant decrease in
radius with increasing wavelength, consistent with the phenomenon of
super-Rayleigh scattering
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Interação medicamentosa em pacientes com câncer: revisão integrativa da literatura / Drug interaction in cancer patients: an integrative literature review
Introdução: O câncer é uma patologia considerada como doença crônica não transmissível, que na sociedade atual, se encontra entre as 7 principais causas de morte no mundo, segundo estimativas da Organização Mundial da Saúde (OMS). Pacientes com neoplasias comumente realizam tratamentos paralelos além dos realizados para combater o câncer, como para tratar: outras doenças crônicas pré - existentes, reações adversas a medicamentos causadas pelo tratamento primário além da auto medicação o que causa as interações medicamentosas as quais desencadeiam efeitos prejudiciais à saúde do paciente, como intoxicação medicamentosa, efeito nulo do medicamento, não tratamento da doença e ênfase nos efeitos adversos daqueles medicamentos Objetivo: objetivou-se analisar as incidência de interação medicamentosa em pacientes com câncer, submetidos ao tratamento quimioterápico. Metodologia: Foi realizada uma revisão bibliográfica por meio da pesquisa de artigos científicos. As bases de dados utilizadas foram BVS, Scielo, Lilacs e PubMed, e foram utilizados como descritores para a pesquisa: “interação medicamentosa e câncer”, “interação medicamentosa, oncologia e quimioterapia” “potenciais interações medicamentosas, neoplasias e agentes anticâncer” “drug interaction and cancer”, “drug interaction oncology and chemotherapy” e “potential drug interactions neoplasms anticancer agents”. Resultados: Foram incluídos os artigos originais completos de acordo com o tema proposto. Foram selecionados quatorze artigos após aplicação dos critérios de inclusão e exclusão. O número médio de medicamentos ministrados por paciente foi entre 7 a 11,7 e as bases de dados variaram entre: Micromedex, Epocrats, Drug Interactions Facts, MedScape e Lexi Interact. O medicamento que foi comumente envolvido nas interações com agentes anticâncer foi a dexametasona, um agente indutor do Citocromo P450 (CYP 450). Considerações finais: Esta revisão demonstrou uma alta prevalência de interações medicamentosa devido à complexidade da farmacoterapia, sendo essencial que se adote métodos para minimização desses dados, enfatizando a necessidade de um foco global intensificado na prevenção de interação em doenças como o câncer
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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