945 research outputs found
Quinoidization of regioregular oligo(THIENO[3,4-b]THIOPHENE)s
Caracterización de oligotiofenosUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Hearsay Exceptions: Adjusting the Ratio of Intuition to Psychological Science
Myers explores hearsay exeptions by examining three exceptions: excited utterances, statements for purposes of diagnosis or treatment, and the residual hearsay exception. The focus is child declarants, and these exceptions play key roles in child abuse litigation
Nitric Oxide: Physiological Functions, Delivery, and Biomedical Applications
Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical complexities. NO-releasing platforms or donors capable of delivering NO in a controlled and sustained manner to target tissues or organs have advanced in the past few decades. This review article discusses in detail the generation of NO via the enzymatic functions of NO synthase as well as from NO donors and the multiple biological and pathological processes that NO modulates. The methods for incorporating of NO donors into diverse biomaterials including physical, chemical, or supramolecular techniques are summarized. Then, these NO-releasing platforms are highlighted in terms of advancing treatment strategies for various medical problems
Altered patterns of retinoblastoma gene product expression in adult soft-tissue sarcomas.
Altered expression of the retinoblastoma (RB) tumour-suppressor gene product (pRB) has been detected in sporadic bone and soft-tissue sarcomas. Earlier studies, analysing small cohorts of sarcoma patients, have suggested that these alterations are more commonly associated with high-grade tumours, metastatic lesions and poorer survival. This study was designed to re-examine the prevalence and clinical significance of altered pRB expression in a large and selected group of soft-tissue sarcomas from 174 adult patients. Representative tissue sections from these sarcomas were analysed by immunohistochemistry using a well-characterised anti-pRB monoclonal antibody. Tumours were considered to have a positive pRB phenotype only when pure nuclear staining was demonstrated, and cases were segregated into one of three groups. Group 1 (n = 36) were patients whose tumours have minimal or undetectable pRB nuclear staining (< 20% of tumour cells) and were considered pRB negative. Patients with tumours staining in a heterogeneous pattern (20-79% of tumour cells) were classified as group 2 (n = 99). The staining of group 3 (n = 39) was strongly positive with a homogeneous pRB nuclear immunoreactivity (80-100% of tumour cells). pRB alterations were frequently observed in both low- and high-grade lesions. Altered pRB expression did not correlate with known predictors of survival and was not itself an independent predictor of outcome in the long-term follow-up. These findings support earlier observations that alterations of pRB expression are common events in soft-tissue sarcomas; nevertheless, long-term follow-up results indicate that altered patterns of pRB expression do not influence clinical outcome of patients affected with soft-tissue sarcomas. It is postulated that RB alterations are primary events in human sarcomas and may be involved in tumorigenesis or early phases of tumour progression in these neoplasias
Principle of Maximum Entropy Applied to Rayleigh-B\'enard Convection
A statistical-mechanical investigation is performed on Rayleigh-B\'enard
convection of a dilute classical gas starting from the Boltzmann equation. We
first present a microscopic derivation of basic hydrodynamic equations and an
expression of entropy appropriate for the convection. This includes an
alternative justification for the Oberbeck-Boussinesq approximation. We then
calculate entropy change through the convective transition choosing mechanical
quantities as independent variables. Above the critical Rayleigh number, the
system is found to evolve from the heat-conducting uniform state towards the
convective roll state with monotonic increase of entropy on the average. Thus,
the principle of maximum entropy proposed for nonequilibrium steady states in a
preceding paper is indeed obeyed in this prototype example. The principle also
provides a natural explanation for the enhancement of the Nusselt number in
convection.Comment: 13 pages, 4 figures; typos corrected; Eq. (66a) corrected to remove a
double counting for ; Figs. 1-4 replace
Causality bounds for neutron-proton scattering
We consider the constraints of causality and unitarity for the low-energy
interactions of protons and neutrons. We derive a general theorem that
non-vanishing partial-wave mixing cannot be reproduced with zero-range
interactions without violating causality or unitarity. We define and calculate
interaction length scales which we call the causal range and the Cauchy-Schwarz
range for all spin channels up to J = 3. For some channels we find that these
length scales are as large as 5 fm. We investigate the origin of these large
lengths and discuss their significance for the choice of momentum cutoff scales
in effective field theory and universality in many-body Fermi systems.Comment: 36 pages, 10 figures, 7 tables, version to appear in Eur. Phys. J.
Adipose tissue concentrations of non-persistent environmental phenols and local redox balance in adults from Southern Spain
The aim was to evaluate the associations of environmental phenol and paraben concentrations with the oxidative
microenvironment in adipose tissue. This study was conducted in a subsample (n=144) of the GraMo cohort
(Southern Spain). Concentrations of 9 phenols and 7 parabens, and levels of oxidative stress biomarkers were
quantified in adipose tissue. Associations were estimated using multivariable linear regression analyses adjusted
for potential confounders.
Benzophenone-3 (BP-3) concentration was borderline associated with enhanced glutathione peroxidase (GPx)
activity [exp(β)=1.20, p=0.060] and decreased levels of reduced glutathione (GSH) [exp(β)=0.55,
p=0.070]. Concentrations of bisphenol A (BPA) and methylparaben (MeP) were associated to lower glutathione
reductase (GRd) activity [exp(β)=0.83, exp(β)=0.72, respectively], and BPA was borderline associated
to increased levels of oxidized glutathione (GSSG) [exp(β)=1.73, p-value=0.062]. MeP was inversely
associated to both hemeoxygenase-1 (HO-1) and superoxide dismustase (SOD) activity, as well as to the levels of
thiobarbituric acid reactive substances (TBARS) [0.75 < exp(β) < 0.79].
Our results suggest that some specific non-persistent pollutants may be associated with a disruption of the
activity of relevant antioxidant enzymes, in addition to the depletion of the glutathione stock. They might act as
a tissue-specific source of free radicals, contributing to the oxidative microenvironment in the adipose tissue.This research was supported
in part by research grants from the European Union Commission
(H2020-EJP-HBM4EU and SOE1/P1/F0082), Biomedical Research
Networking Center-CIBER de Epidemiología y Salud Pública
(CIBERESP), from the Institute of Health Carlos III, supported by
European Regional Development Fund/FEDER (FIS-PI13/02406, FISPI14/
00067, FIS-PI16/01820, FIS-PI16/01812, FIS-PI16/01858 and
FIS-PI17/01743), and from the Consejería de Salud, Junta de Andalucía
(PS-0506-2016). Funding for the equipment used was provided by
Velux Fonden, Augustinus Fonden and Svend Andersen Fonden. The
authors thank Kirsten og Freddy Johansens Fond and the International
Centre for Research and Research Training in Endocrine Disruption of
Male Reproduction and Child Health (EDMaRC, Rigshospitalet,
Copenhagen University) for economic support. Dr. Juan Pedro Arrebola
is under contract within Ramón y Cajal Program (Ministerio de
Economía, Industria y Competitividad de España, RYC-2016-20155)
Family history of cancer, body weight, and p53 nuclear overexpression in Duke's C colorectal cancer.
To examine the hypothesis that colorectal carcinomas with and without TP53 mutations may be characterised by aetiological heterogeneity, we analysed a group of 107 patients with primary Dukes' C colorectal cancer seen at the Memorial Sloan-Kettering Cancer Center (MSKCC) from 1986 to 1990. We assessed p53 overexpression using the monoclonal antibody PAb 1801, and identified 42 (39%) patients displaying p53-positive phenotype, defined as > or = 25% of positive cells. Patients with two or more first-degree relatives with cancer had an odds ratio (OR) of 2.9 (95% CI 1.0-8.3) for p53 overexpression in comparison with those without a family history of cancer (trend test, P = 0.11). A possible association between body weight and p53 overexpression was observed. The ORs were 1.9 for the second quartile, 1.9 for the third quartile and 3.4 for the highest quartile in comparison with the lowest quartile (trend test, P = 0.06). No association between occupational physical activity, smoking, drinking, parity and p53 overexpression was identified. The results suggest that p53 overexpression may be related to genetic predisposition to colorectal cancer, and p53-positive and p53-negative colorectal cancers may be controlled by different aetiological pathways
Benzotrithiophenes vs. Benzo/Naptha-dithiophenes: The Effect of Star-Shaped versus Linear Conjugation on Their Electronic Structures
Star-shaped complexes of π-conjugated chromophores are currently of great interest for use in optoelectronic devices.1 Recently, different planar central cores involving three thiophene rings fused to a benzenic ring (BTTs) have been described. In these systems, the coplanarity and extended π-conjugation of the BTT skeleton should promote intermolecular π-stacking, which would induce strong aggregation and enhanced packing in the solid state of BTT-containing molecules. We propose here the study of a BTT conjugated system with DPPT fragments, in which three DPP2T units are linked to a central rigid trithienobenzene core. Comparison with homologous linear systems, based on the benzodithiophene (BDT) unit and the naphtodithiophene (NDT) unit,2 will be carried out in order to elucidate the effect of star-shaped configuration versus linear conformation on the optical and electrical properties.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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