186 research outputs found

    Electron-phonon renormalization of the absorption edge of the cuprous halides

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    Compared to most tetrahedral semiconductors, the temperature dependence of the absorption edges of the cuprous halides (CuCl, CuBr, CuI) is very small. CuCl and CuBr show a small increase of the gap E0E_0 with increasing temperature, with a change in the slope of E0E_0 vs. TT at around 150 K: above this temperature, the variation of E0E_0 with TT becomes even smaller. This unusual behavior has been clarified for CuCl by measurements of the low temperature gap vs. the isotopic masses of both constituents, yielding an anomalous negative shift with increasing copper mass. Here we report the isotope effects of Cu and Br on the gap of CuBr, and that of Cu on the gap of CuI. The measured isotope effects allow us to understand the corresponding temperature dependences, which we also report, to our knowledge for the first time, in the case of CuI. These results enable us to develop a more quantitative understanding of the phenomena mentioned for the three halides, and to interpret other anomalies reported for the temperature dependence of the absorption gap in copper and silver chalcogenides; similarities to the behavior observed for the copper chalcopyrites are also pointed out.Comment: 14 pages, 5 figures, submitted to Phys. Rev.

    Patients visiting the complementary medicine clinic for pain: a cross sectional study

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    <p>Abstract</p> <p>Background</p> <p>Pain is one of the most common reasons for seeking medical care. The purpose of this study was to characterize patients visiting the complementary medicine clinic for a pain complaint.</p> <p>Methods</p> <p>This is a cross-sectional study. The study took place at Clalit Health Services (CHS) complementary clinic in Beer-Sheva, Israel. Patients visiting the complementary clinic, aged 18 years old and older, Hebrew speakers, with a main complaint of pain were included. Patients were recruited consecutively on random days of the month during a period of six months. Main outcome measures were: pain levels, location of pain, and interference with daily activities. Once informed consent was signed patients were interviewed using a structured questionnaire by a qualified nurse. The questionnaire included socio-demographic data, and the Brief Pain Inventory (BPI).</p> <p>Results</p> <p>Three-hundred and ninety-five patients were seen at the complementary medicine clinic during the study period, 201 (50.8%) of them met the inclusion criteria. Of them, 163 (81.1%) agreed to participate in the study and were interviewed. Pain complaints included: 69 patients (46.6%) with back pain, 65 (43.9%) knee pain, and 28 (32.4%) other limbs pain. Eighty-two patients (50.3%) treated their pain with complementary medicine as a supplement for their conventional treatment, and 55 (33.7%) felt disappointed from the conventional medicine experience. Eighty-three patients (50.9%) claimed that complementary medicine can result in better physical strength, or better mental state 51 (31.3%). Thirty-seven patients (22.7%) were hoping that complementary medicine will prevent invasive procedures.</p> <p>Conclusion</p> <p>Given the high proportion of patients with unsatisfactory pain relief using complementary and alternative medicine (CAM), general practitioners should gain knowledge about CAM and CAM providers should gain training in pain topics to improve communication and counsel patients. More clinical research to evaluate safety and efficiency of CAM for pain is needed to provide evidence based counseling.</p

    Congenital Heart Disease–Causing Gata4 Mutation Displays Functional Deficits In Vivo

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    Defects of atrial and ventricular septation are the most frequent form of congenital heart disease, accounting for almost 50% of all cases. We previously reported that a heterozygous G296S missense mutation of GATA4 caused atrial and ventricular septal defects and pulmonary valve stenosis in humans. GATA4 encodes a cardiac transcription factor, and when deleted in mice it results in cardiac bifida and lethality by embryonic day (E)9.5. In vitro, the mutant GATA4 protein has a reduced DNA binding affinity and transcriptional activity and abolishes a physical interaction with TBX5, a transcription factor critical for normal heart formation. To characterize the mutation in vivo, we generated mice harboring the same mutation, Gata4 G295S. Mice homozygous for the Gata4 G295S mutant allele have normal ventral body patterning and heart looping, but have a thin ventricular myocardium, single ventricular chamber, and lethality by E11.5. While heterozygous Gata4 G295S mutant mice are viable, a subset of these mice have semilunar valve stenosis and small defects of the atrial septum. Gene expression studies of homozygous mutant mice suggest the G295S protein can sufficiently activate downstream targets of Gata4 in the endoderm but not in the developing heart. Cardiomyocyte proliferation deficits and decreased cardiac expression of CCND2, a member of the cyclin family and a direct target of Gata4, were found in embryos both homozygous and heterozygous for the Gata4 G295S allele. To further define functions of the Gata4 G295S mutation in vivo, compound mutant mice were generated in which specific cell lineages harbored both the Gata4 G295S mutant and Gata4 null alleles. Examination of these mice demonstrated that the Gata4 G295S protein has functional deficits in early myocardial development. In summary, the Gata4 G295S mutation functions as a hypomorph in vivo and leads to defects in cardiomyocyte proliferation during embryogenesis, which may contribute to the development of congenital heart defects in humans

    Management of primary chronic headache in the general population: the Akershus study of chronic headache

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    Primary chronic headaches cause more disability and necessitate high utilisation of health care. Our knowledge is based on selected populations, while information from the general population is largely lacking. An age and gender-stratified cross-sectional epidemiological survey included 30,000 persons aged 30–44 years. Respondents with self-reported chronic headache were interviewed by physicians. The International Classification of Headache Disorders was used. Of all primary chronic headache sufferers, 80% had consulted their general practitioner (GP), of these 19% had also consulted a neurologist and 4% had been hospitalised. Co-occurrence of migraine increased the probability of contact with a physician. A high Severity of Dependence Scale score increased the probability for contact with a physician. Complementary and alternative medicine (CAM) was used by 62%, most often physiotherapy, acupuncture and chiropractic. Contact with a physician increased the probability of use of CAM. Acute headache medications were taken by 87%, while only 3% used prophylactic medication. GPs manage the majority of those with primary chronic headache, 1/5 never consults a physician for their headache, while approximately 1/5 is referred to a neurologist or hospitalised. Acute headache medication was frequently overused, while prophylactic medication was rarely used. Thus, avoidance of acute headache medication overuse and increased use of prophylactic medication may improve the management of primary chronic headaches in the future

    Use of complementary and alternative medicines by a sample of Turkish women for infertility enhancement: a descriptive study

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    <p>Abstract</p> <p>Background</p> <p>Infertility patients are a vulnerable group that often seeks a non-medical solution for their failure to conceive. World-wide, women use CAM for productive health, but only a limited number of studies report on CAM use to enhance fertility. Little is known about traditional and religious forms of therapies that are used in relation to conventional medicine in Turkey. We investigated the prevalence and types of complementary and alternative medicine (CAM) used by infertile Turkish women for fertility enhancement.</p> <p>Methods</p> <p>A face-to-face questionnaire inquiring demographic information and types of CAM used for fertility enhancement were completed by hundred infertility patients admitted to a primary care family planning centre in Van, Turkey between January and July 2009.</p> <p>Results</p> <p>The vast majority of infertile women had used CAM at least once for infertility. CAM use included religious interventions, herbal products and recommendations of traditional "hodja's" (faith healers). Of these women, 87.8% were abused in the last 12 months, 36.6% felt not being supported by her partner and 80.5% had never spoken with a physician about CAM.</p> <p>Conclusions</p> <p>Infertile Turkish women use complementary medicine frequently for fertility enhancement and are in need of information about CAM. Religious and traditional therapies are used as an adjunct to, rather than a substitute for, conventional medical therapy. Physicians need to approach fertility patients with sensitivity and should be able to council their patients about CAM accordingly.</p

    Characterization of Apoptosis-Related Oxidoreductases from Neurospora crassa

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    The genome from Neurospora crassa presented three open reading frames homologous to the genes coding for human AIF and AMID proteins, which are flavoproteins with oxidoreductase activities implicated in caspase-independent apoptosis. To investigate the role of these proteins, namely within the mitochondrial respiratory chain, we studied their cellular localization and characterized the respective null mutant strains. Efficiency of the respiratory chain was analyzed by oxygen consumption studies and supramolecular organization of the OXPHOS system was assessed through BN-PAGE analysis in the respective null mutant strains. The results demonstrate that, unlike in mammalian systems, disruption of AIF in Neurospora does not affect either complex I assembly or function. Furthermore, the mitochondrial respiratory chain complexes of the mutant strains display a similar supramolecular organization to that observed in the wild type strain. Further characterization revealed that N. crassa AIF appears localized to both the mitochondria and the cytoplasm, whereas AMID was found exclusively in the cytoplasm. AMID2 was detected in both mitochondria and cytoplasm of the amid mutant strain, but was barely discernible in wild type extracts, suggesting overlapping functions for the two proteins

    MLH1 mediates PARP-dependent cell death in response to the methylating agent N-methyl-N-nitrosourea

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    Background:Methylating agents such as N-methyl-N-nitrosourea (MNU) can cause cell cycle arrest and death either via caspase-dependent apoptosis or via a poly(ADP-ribose) polymerase (PARP)-dependent form of apoptosis. We wished to investigate the possible role of MLH1 in signalling cell death through PARP.Methods:Fibroblasts are particularly dependent on a PARP-mediated cell death response to methylating agents. We used hTERT-immortalised normal human fibroblasts (WT) to generate isogenic MLH1-depleted cells, confirmed by quantitative PCR and western blotting. Drug resistance was measured by clonogenic and cell viability assays and effects on the cell cycle by cell sorting. Damage signalling was additionally investigated using immunostaining.Results:MLH1-depleted cells were more resistant to MNU, as expected. Despite having an intact G2/M checkpoint, the WT cells did not initially undergo cell cycle arrest but instead triggered cell death directly by PARP overactivation and nuclear translocation of apoptosis-inducing factor (AIF). The MLH1-depleted cells showed defects in this pathway, with decreased staining for phosphorylated H2AX, altered PARP activity and reduced AIF translocation. Inhibitors of PARP, but not of caspases, blocked AIF translocation and greatly decreased short-term cell death in both WT and MLH1-depleted cells. This MLH1-dependent response to MNU was not blocked by inhibitors of ATM/ATR or p53.Conclusion:These novel data indicate an important role for MLH1 in signalling PARP-dependent cell death in response to the methylating agent MNU

    Australian women's use of complementary and alternative medicines to enhance fertility: exploring the experiences of women and practitioners

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    <p>Abstract</p> <p>Background</p> <p>Studies exploring the use of complementary and alternative medicine (CAM) to enhance fertility are limited. While Australian trends indicate that women are using CAM during pregnancy, little is known about women's use of CAM for fertility enhancement. With the rising age of women at first birth, couples are increasingly seeking assisted reproductive technologies (ART) to achieve parenthood. It is likely that CAM use for fertility enhancement will also increase, however this is not known. This paper reports on an exploratory study of women's use of CAM for fertility enhancement.</p> <p>Methods</p> <p>Three focus groups were conducted in Melbourne, Australia in 2007; two with women who used CAM to enhance their fertility and one with CAM practitioners. Participants were recruited from five metropolitan Melbourne CAM practices that specialise in women's health. Women were asked to discuss their views and experiences of both CAM and ART, and practitioners were asked about their perceptions of why women consult them for fertility enhancement. Groups were digitally recorded (audio) and transcribed verbatim. The data were analysed thematically.</p> <p>Results</p> <p>Focus groups included eight CAM practitioners and seven women. Practitioners reported increasing numbers of women consulting them for fertility enhancement whilst also using ART. Women combined CAM with ART to maintain wellbeing and assist with fertility enhancement. Global themes emerging from the women's focus groups were: women being willing to 'try anything' to achieve a pregnancy; women's negative experiences of ART and a reluctance to inform their medical specialist of their CAM use; and conversely, women's experiences with CAM being affirming and empowering.</p> <p>Conclusions</p> <p>The women in our study used CAM to optimise their chances of achieving a pregnancy. Emerging themes suggest the positive relationships achieved with CAM practitioners are not always attained with orthodox medical providers. Women's views and experiences need to be considered in the provision of fertility services, and strategies developed to enhance communication between women, medical practitioners and CAM practitioners. Further research is needed to investigate the extent of CAM use for fertility enhancement in Australia, and to explore the efficacy and safety of CAM use to enhance fertility, in isolation or with ART.</p
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