Anisotropic Structure of the Order Parameter in FeSe0.45Te0.55 Revealed by Angle Resolved Specific Heat

The symmetry and structure of the superconducting gap in the Fe-based superconductors are the central issue for understanding these novel materials. So far the experimental data and theoretical models have been highly controversial. Some experiments favor two or more constant or nearly-constant gaps, others indicate strong anisotropy and yet others suggest gap zeros ("nodes"). Theoretical models also vary, suggesting that the absence or presence of the nodes depends quantitatively on the model parameters. An opinion that has gained substantial currency is that the gap structure, unlike all other known superconductors, including cuprates, may be different in different compounds within the same family. A unique method for addressing this issue, one of the very few methods that are bulk and angle-resolved, calls for measuring the electronic specific heat in a rotating magnetic field, as a function of field orientation with respect to the crystallographic axes. In this Communication we present the first such measurement for an Fe-based high-Tc superconductor (FeBSC). We observed a fourfold oscillation of the specific heat as a function of the in-plane magnetic field direction, which allowed us to identify the locations of the gap minima (or nodes) on the Fermi surface. Our results are consistent with the expectations of an extended s-wave model with a significant gap anisotropy on the electron pockets and the gap minima along the \Gamma M (or Fe-Fe bond) direction.Comment: 32 pages, 7 figure

Natural variation in immune responses to neonatal mycobacterium bovis bacillus calmette-guerin (BCG) vaccination in a cohort of Gambian infants

Background There is a need for new vaccines for tuberculosis (TB) that protect against adult pulmonary disease in regions where BCG is not effective. However, BCG could remain integral to TB control programmes because neonatal BCG protects against disseminated forms of childhood TB and many new vaccines rely on BCG to prime immunity or are recombinant strains of BCG. Interferon-gamma (IFN-) is required for immunity to mycobacteria and used as a marker of immunity when new vaccines are tested. Although BCG is widely given to neonates IFN- responses to BCG in this age group are poorly described. Characterisation of IFN- responses to BCG is required for interpretation of vaccine immunogenicity study data where BCG is part of the vaccination strategy. Methodology/Principal Findings 236 healthy Gambian babies were vaccinated with M. bovis BCG at birth. IFN-, interleukin (IL)-5 and IL-13 responses to purified protein derivative (PPD), killed Mycobacterium tuberculosis (KMTB), M. tuberculosis short term culture filtrate (STCF) and M. bovis BCG antigen 85 complex (Ag85) were measured in a whole blood assay two months after vaccination. Cytokine responses varied up to 10 log-fold within this population. The majority of infants (89-98% depending on the antigen) made IFN- responses and there was significant correlation between IFN- responses to the different mycobacterial antigens (Spearman’s coefficient ranged from 0.340 to 0.675, p=10-6-10-22). IL-13 and IL-5 responses were generally low and there were more non-responders (33-75%) for these cytokines. Nonetheless, significant correlations were observed for IL-13 and IL-5 responses to different mycobacterial antigens Conclusions/Significance Cytokine responses to mycobacterial antigens in BCG-vaccinated infants are heterogeneous and there is significant inter-individual variation. Further studies in large populations of infants are required to identify the factors that determine variation in IFN- responses

Distinct Binding and Immunogenic Properties of the Gonococcal Homologue of Meningococcal Factor H Binding Protein

Neisseria meningitidis is a leading cause of sepsis and meningitis. The bacterium recruits factor H (fH), a negative regulator of the complement system, to its surface via fH binding protein (fHbp), providing a mechanism to avoid complement-mediated killing. fHbp is an important antigen that elicits protective immunity against the meningococcus and has been divided into three different variant groups, V1, V2 and V3, or families A and B. However, immunisation with fHbp V1 does not result in cross-protection against V2 and V3 and vice versa. Furthermore, high affinity binding of fH could impair immune responses against fHbp. Here, we investigate a homologue of fHbp in Neisseria gonorrhoeae, designated as Gonococcal homologue of fHbp (Ghfp) which we show is a promising vaccine candidate for N. meningitidis. We demonstrate that Gfhp is not expressed on the surface of the gonococcus and, despite its high level of identity with fHbp, does not bind fH. Substitution of only two amino acids in Ghfp is sufficient to confer fH binding, while the corresponding residues in V3 fHbp are essential for high affinity fH binding. Furthermore, immune responses against Ghfp recognise V1, V2 and V3 fHbps expressed by a range of clinical isolates, and have serum bactericidal activity against N. meningitidis expressing fHbps from all variant groups

Myocardial infarction risk and tamoxifen therapy for breast cancer

Tamoxifen prevents recurrence after breast cancer and breast cancer among high-risk women, and may prevent myocardial infarction (MI). To assess the impact of tamoxifen on MI risk, we conducted a case–control study of first MI after breast cancer nested among women diagnosed with breast cancer, while enrolled in a health maintenance organisation from 1980 to 2000. We obtained information on breast cancer treatment and MI risk factors through medical record reviews and interviews. Data were analysed using conditional logistic regression. Of 11 045 women with breast cancer, 134 met MI criteria and were matched to two MI-free control subjects on year of birth and breast cancer diagnosis. After adjusting for smoking, hypertension and diabetes, tamoxifen was unassociated with MI (odds ratio (OR)=1.2, 95% confidence interval (CI)=0.7–1.9). Duration, cumulative dose and recency of use were not associated with MI. Radiation therapy was associated with MI (OR=2.0, 95% CI=1.1–3.5), an association that varied slightly but not statistically significantly by tamoxifen use (radiation with tamoxifen, OR=2.0, 95% CI=0.9–4.4; radiation without tamoxifen, OR=2.9, 95% CI=1.2–7.5). Tamoxifen treatment for breast cancer does not appear to increase or decrease MI risk, although radiation therapy appears to increase MI risk

Practice of ALARA in the pediatric interventional suite

As interventional procedures have become progressively more sophisticated and lengthy, the potential for high patient radiation dose has increased. Staff exposure arises from patient scatter, so steps to minimize patient dose will in turn reduce operator and staff dose. The practice of ALARA in an interventional radiology (IR) suite, therefore, requires careful attention to technical detail in order to reduce patient dose. The choice of imaging modality should minimize radiation when and where possible. In this paper practical steps are outlined to reduce patient dose. Further details are included that specifically reduce operator exposure. Challenges unique to pediatric intervention are reviewed. Reference is made to experience from modern pediatric interventional suites. Given the potential for high exposures, the practice of ALARA is a team responsibility. Various measures are outlined for consideration when implementing a quality assurance (QA) program for an IR service

Towards Heat-stable Oxytocin Formulations: Analysis of Degradation Kinetics and Identification of Degradation Products

Purpose. To investigate degradation kinetics of oxytocin as a function of temperature and pH, and identify the degradation products. Materials and Methods. Accelerated degradation of oxytocin formulated at pH 2.0, 4.5, 7.0 and 9.0 was performed at 40, 55, 70 and 80°C. Degradation rate constants were determined from RP-HPLC data. Formulations were characterized by HP-SEC, UV absorption and fluorescence spectroscopy. Degradation products were identified by ESI-MS/MS. Results. The loss of intact oxytocin in RP-HPLC was pH- and temperature-dependent and followed (pseudo) first order kinetics. Degradation was fastest at pH 9.0, followed by pH 7.0, pH 2.0 and pH 4.5. The Arrhenius equation proved suitable to describe the kinetics, with the highest activation energy (116.3 kJ/mol) being found for pH 4.5 formulations. At pH 2.0 deamidation of Gln 4, Asn 5, and Gly 9-NH2, as well as combinations thereof were found. At pH 4.5, 7.0 and 9.0, the formation of tri- and tetrasulfidecontaining oxytocin as well as different types of disulfide and dityrosine-linked dimers were found to occur. Beta-elimination and larger aggregates were also observed. At pH 9.0, mono-deamidation of Gln 4, Asn 5, and Gly 9-NH2 additionally occurred. Conclusions. Multiple degradation products of oxytocin have been identified unequivocally, including various deamidated species, intramolecular oligosulfides and covalent aggregates. The strongly pH dependent degradation can be described by the Arrhenius equation. KEY WORDS: aggregation; Arrhenius kinetics; degradation; mass spectrometry; oxytocin

A Josephson Quantum Electron Pump

A macroscopic fluid pump works according to the law of Newtonian mechanics and transfers a large number of molecules per cycle (of the order of 10^23). By contrast, a nano-scale charge pump can be thought as the ultimate miniaturization of a pump, with its operation being subject to quantum mechanics and with only few electrons or even fractions of electrons transfered per cycle. It generates a direct current in the absence of an applied voltage exploiting the time-dependence of some properties of a nano-scale conductor. The idea of pumping in nanostructures was discussed theoretically a few decades ago [1-4]. So far, nano-scale pumps have been realised only in system exhibiting strong Coulombic effects [5-12], whereas evidence for pumping in the absence of Coulomb-blockade has been elusive. A pioneering experiment by Switkes et al. [13] evidenced the difficulty of modulating in time the properties of an open mesoscopic conductor at cryogenic temperatures without generating undesired bias voltages due to stray capacitances [14,15]. One possible solution to this problem is to use the ac Josephson effect to induce periodically time-dependent Andreev-reflection amplitudes in a hybrid normal-superconducting system [16]. Here we report the experimental detection of charge flow in an unbiased InAs nanowire (NW) embedded in a superconducting quantum interference device (SQUID). In this system, pumping may occur via the cyclic modulation of the phase of the order parameter of different superconducting electrodes. The symmetry of the current with respect to the enclosed magnetic flux [17,18] and bias SQUID current is a discriminating signature of pumping. Currents exceeding 20 pA are measured at 250 mK, and exhibit symmetries compatible with a pumping mechanism in this setup which realizes a Josephson quantum electron pump (JQEP).Comment: 7+ pages, 6 color figure

Sensitivity and specificity of lung cancer screening using chest low-dose computed tomography

Lung cancer screening programmes using chest X-ray and sputum cytology are routinely performed in Japan; however, the efficacy is insufficient. Screening using low-dose computed tomography (CT) is a more effective approach and has the potential to detect the disease more accurately. A total of 7183 low-dose CT screening tests for 4689 participants and 36 085 chest X-ray screening tests for 13 381 participants were conducted between August 1998 and May 2002. Sensitivity and specificity of lung cancer screening were calculated by both the detection method and the incidence method by linkage of the screening database and the Cancer Registry database. The preclinical detectable phase was assumed to be 1 year. Sensitivity and specificity by the detection method were 88.9 and 92.6% for low-dose CT and 78.3 and 97.0% for chest X-ray, respectively. Sensitivity of low-dose CT by the incidence method was 79.5%, whereas that of chest X-ray was 86.5%. Lung cancer screening using low-dose CT resulted in higher sensitivity and lower specificity than traditional screening according to the detection method. However, sensitivity by the incidence method was not as high as this. These findings demonstrate the potential for overdiagnosis in CT screening-detected cases

The impact of radiotherapy in the treatment of desmoid tumours. An international survey of 110 patients. A study of the Rare Cancer Network

PURPOSE: A multi-centre study to assess the value of combined surgical resection and radiotherapy for the treatment of desmoid tumours. PATIENTS AND METHODS: One hundred and ten patients from several European countries qualified for this study. Pathology slides of all patients were reviewed by an independent pathologist. Sixty-eight patients received post-operative radiotherapy and 42 surgery only. Median follow-up was 6 years (1 to 44). The progression-free survival time (PFS) and prognostic factors were analysed. RESULTS: The combined treatment with radiotherapy showed a significantly longer progression-free survival than surgical resection alone (p smaller than 0.001). Extremities could be preserved in all patients treated with combined surgery and radiotherapy for tumours located in the limb, whereas amputation was necessary for 23% of patients treated with surgery alone. A comparison of PFS for tumour locations proved the abdominal wall to be a positive prognostic factor and a localization in the extremities to be a negative prognostic factor. Additional irradiation, a fraction size larger than or equal to 2 Gy and a total dose larger than 50 Gy to the tumour were found to be positive prognostic factors with a significantly lower risk for a recurrence in the univariate analysis. This analysis revealed radiotherapy at recurrence as a significantly worse prognostic factor compared with adjuvant radiotherapy. The addition of radiotherapy to the treatment concept was a positive prognostic factor in the multivariate analysis. CONCLUSION: Postoperative radiotherapy significantly improved the PFS compared to surgery alone. Therefore it should always be considered after a non-radical tumour resection and should be given preferably in an adjuvant setting. It is effective in limb preservation and for preserving the function of joints in situations where surgery alone would result in deficits, which is especially important in young patients