Complex periodic potentials with real band spectra

This paper demonstrates that complex PT-symmetric periodic potentials possess real band spectra. However, there are significant qualitative differences in the band structure for these potentials when compared with conventional real periodic potentials. For example, while the potentials V(x)=i\sin^{2N+1}(x), (N=0, 1, 2, ...), have infinitely many gaps, at the band edges there are periodic wave functions but no antiperiodic wave functions. Numerical analysis and higher-order WKB techniques are used to establish these results.Comment: 8 pages, 7 figures, LaTe

Inherited predisposition to spontaneous preterm delivery

Peer reviewedPreprin

Oxidized low-density lipoprotein and ankle-brachial pressure index in patients with clinically evident peripheral arterial disease

OBJECTIVES: To investigate whether oxidized low-density lipoprotein is a suitable predictor of peripheral arterial disease severity. The role of oxidized low-density lipoprotein in the pathogenesis of atherosclerosis has already been investigated. Its relevance as a predictor of the appearance and worsening of coronary arterial disease is also well known. However, the same is not true regarding peripheral arterial disease. METHOD: Eighty-five consecutive patients with an ankle-brachial pressure index (ABPI) < 0.9 and the presence of either intermittent claudication or critical lower leg ischemia were included. The plasma level of IgG autoantibodies against oxidized low-density lipoprotein was evaluated through an enzyme-linked immunosorbent assay. The results were categorized into quartiles according to the ankle-brachial pressure index (a marker of peripheral arterial disease severity), and significant differences were investigated with the Kruskal-Wallis test. RESULTS: There was no significant difference between the quartiles for this population (p = 0.33). No correlation was found between the ankle-brachial pressure index and oxidized low-density lipoprotein levels in subjects with clinically evident peripheral arterial disease with a wide range of clinical manifestations. CONCLUSIONS: Oxidized low-density lipoprotein is not a good predictor of peripheral arterial disease severity

Time reparameterization in Bianchi type I spinor cosmology

The problem of time reparameterization is addressed at both the classical and quantum levels in a Bianchi-I universe in which the matter source is a massive Dirac spinor field. We take the scale factors of the metric as the intrinsic time and their conjugate momenta as the extrinsic time. A scalar character of the spinor field is identified as a representation of the extrinsic time. The construction of the field equations and quantization of the model is achieved by solving the Hamiltonian constraint after time identification has been dealt with. This procedure leads to a true Hamiltonian whose exact solutions for the above choices of time are presentedComment: 16 pages, no figures, to appear in Annals of Physic

Age at menarche and cardiometabolic health::a sibling analysis in the Scottish Family Health Study

Background: Previous studies of age at menarche and cardiometabolic health report conflicting findings, and only a few could account for childhood characteristics. We aimed to estimate the associations of age at menarche with cardiovascular risk factors in unrelated women and within sister groups, under the assumption that within‐sibship estimates will be better adjusted for shared genetics and early life environment. Methods and Results: Our study included 7770 women, from 5984 sibships, participating in the GS:SFHS (Generation Scotland: Scottish Family Health Study). We used fixed‐ and between‐effects linear regression to estimate the associations within sister groups and between unrelated individuals, respectively. Within sibships, the mean difference between sisters with early menarche (≤11 years) and sisters with menarche at 12 to 13 years was 1.73 mm Hg (95% confidence interval [CI], −0.41 to 3.86) for systolic blood pressure, 1.26 mm Hg (95% CI, −0.02 to 2.55) for diastolic blood pressure, −0.06 nmol/L (95% CI, −0.11 to −0.02) for high‐density lipoprotein, 0.20 nmol/L (95% CI, 0.08–0.32) for non–high‐density lipoprotein, −0.34% (95% CI, −1.98 to 1.30) for glucose, 1.60 kg/m2 (95% CI, 0.92–2.28) for body mass index, and 2.75 cm (95% CI, 1.06–4.44) for waist circumference. There was weak evidence of associations between later menarche (14–15 or ≥16 years) and lower body mass index, waist circumference, and blood pressure. We found no strong evidence that estimates from within‐ and between‐sibship analyses differed (all P values &#62;0.1). The associations with other cardiovascular risk factors were attenuated after adjustment for adult body mass index. Conclusions: Our results suggest that confounding by shared familial characteristics is unlikely to be a major driver of the association between early menarche and adverse cardiometabolic health but do not exclude confounding by individual‐level characteristics

Exact Solution of the Klein-Gordon Equation for the PT-Symmetric Generalized Woods-Saxon Potential by the Nikiforov-Uvarov Method

The one-dimensional Klein-Gordon (KG) equation has been solved for the PT-symmetric generalized Woods-Saxon (WS) potential. The Nikiforov-Uvarov(NU} method which is based on solving the second-order linear differential equations by reduction to a generalized equation of hypergeometric type is used to obtain exact energy eigenvalues and corresponding eigenfunctions. We have also investigated the positive and negative exact bound states of the s-states for different types of complex generalized WS potentials.Comment: 29 pages, 8 figure

Number of Offspring and Cardiovascular Disease Risk in Men and Women: The Role of Shared Lifestyle Characteristics

Previous studies of the number of offspring and cardiovascular disease (CVD) report conflicting findings. We re-examined this association in both sexes to clarify the role of the cardiometabolic changes that women experience during pregnancy versus shared lifestyle characteristics. We studied 180,626 women and 133,259 men participating in the UK Biobank cohort who were free of CVD at baseline. CVD events were obtained from hospital and death registers. Analyses were conducted using Cox proportional hazards regression. The incidence rates of overall CVD were 6 per 1,000 person years for women and 9 per 1,000 person years for men. Number of children showed an association with risk of CVD among women; the adjusted HR (95% CI) was 1.2 (1.1, 1.3) for one, 1.1 (1.0, 1.2) for two, 1.2 (1.1, 1.3) for three and 1.2 (1.1, 1.4) for four or more as compared to none. Number of children was also associated with CVD among men; the adjusted HR (95% CI) was 1.1 (1.0, 1.2) for one, 1.0 (0.96, 1.1) for two, 1.1 (1.0, 1.2) for three and 1.1 (1.0, 1.3) for four or more as compared to none. There was no evidence of heterogeneity in the associations between sexes (p-value interaction 0.80). Number of offspring showed similar associations with ischemic heart disease and hypertensive disorders in both sexes. We observed similar associations between number of offspring and CVD in both sexes. The association among women might therefore be largely explained by unobserved behavioral and lifestyle characteristics

Inflammatory environment and immune responses to oxidized LDL are linked to systolic and diastolic blood pressure levels in hypertensive subjects

Universidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04039030 São Paulo, BrazilUniv São Paulo, Dept Immunol, São Paulo, BrazilNatl Inst Complex Fluids, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04039030 São Paulo, BrazilWeb of Scienc

Recommended age groups and frequency of mammography screening : a systematic review

Esta revisão teve por objetivo avaliar a força de evidência do atual indicador de desempenho português relativo ao rastreio do Câncer da Mama através da mamografia, de modo a determinar o grupo etário e a periodicidade recomendadas. Foram pesquisados artigos nas principais bases de dados internacionais de literatura médica. Incluímos artigos publicados entre Janeiro de 2006 e Janeiro de 2012 que correspondiam aos objetivos da revisão. Foi utilizada a taxonomia SORT para a classificação dos resultados. Dos 253 artigos encontrados foram selecionados cinco que cumpriam os critérios de inclusão. Estes incluem três revisões sistemáticas (RS), uma meta-análise (MA) e uma norma de orientação clínica (NOC) baseada numa RS. Os artigos selecionados avaliaram a redução da mortalidade por câncer da mama através do rastreio com mamografia. A realização do rastreio mamográfico entre os 50 e os 69 anos é recomendado em todos os artigos que avaliam esta faixa etária. A NOC recomenda o rastreio bienal. Em suma, a mamografia deverá ser realizada entre os 50 e os 69 anos com uma periodicidade bienal. Estes resultados vão ao encontro do atual indicador de desempenho do rastreio do câncer da mama em Portugal.The scope of this review was to assess the strength of evidence for the current Portuguese performance indicator on breast cancer screening with mammography in order to determine the recommended age group and periodicity for screening. A search for articles was conducted in the main international databases of medical literature. Articles published between January 2006 and January 2012 addressing the objectives of this review were included. The SORT taxonomy was used to classify the results. Of the 253 articles, five articles met the inclusion criteria and were selected for review. These included three systematic reviews, one meta-analysis and one clinical guideline based on a systematic review. A reduction in breast cancer mortality with mamography screening was the outcome in all articles selected. Mammography screening between 50 and 69 years was recommended in all articles that assess this age group. The clinical guidelines recommended screening every two years. In conclusion, the current literature recommends mammography for women every two years between the ages of 50 and 69 years. This is consistent with the current performance indicator for breast cancer screening in Portugal