Baseline Prostate-specific Antigen Level in Midlife and Aggressive Prostate Cancer in Black Men

Background

Prostate-specific antigen (PSA) measurement in midlife predicts long-term prostate cancer (PCa) mortality among white men.

Superconductivity-driven ferromagnetism and spin manipulation using vortices in the magnetic superconductor EuRbFe4As4

Magnetic superconductors are specific materials exhibiting two antagonistic phenomena, superconductivity and magnetism, whose mutual interaction induces various emergent phenomena, such as the reentrant superconducting transition associated with the suppression of superconductivity around the magnetic transition temperature (T_m), highlighting the impact of magnetism on superconductivity. In this study, we report the experimental observation of the ferromagnetic order induced by superconducting vortices in the high-critical-temperature (high-T_c) magnetic superconductor EuRbFe₄As₄. Although the ground state of the Eu²⁺ moments in EuRbFe₄As₄ is helimagnetism below T_m, neutron diffraction and magnetization experiments show a ferromagnetic hysteresis of the Eu²⁺ spin alignment. We demonstrate that the direction of the Eu²⁺ moments is dominated by the distribution of pinned vortices based on the critical state model. Moreover, we demonstrate the manipulation of spin texture by controlling the direction of superconducting vortices, which can help realize spin manipulation devices using magnetic superconductors.

The coexistence of superconductivity and magnetism has been a long-standing issue in the field of superconductivity due to the antagonistic nature of these two ordered states. Therefore, magnetic superconductors, exhibiting both behaviors simultaneously, have played an important role in the study of their interaction. Various novel phenomena have been reported in magnetic superconductors containing rare earth elements (R) such as Ho and Er, for example, RRh₄B₄ (T_c ∼9 K and T_m ∼1 K) (1), RMo₆S₈ (T_c ∼2 K and T_m ∼0.2 to 1 K) (2), and RNi₂B₂C (T_c ∼5 to 10 K and T_m ∼2 to 6 K) (3, 4), including reentrant superconducting transition, anomalous temperature dependence of the upper critical field, and enhanced vortex pinning (or critical current density [J_c]) associated with the magnetic transition. All have contributed significantly to the development of superconductivity research.Recently, iron-based superconductors containing Eu (Eu-IBSs) have attracted attention as a new class of magnetic superconductors (5). Eu-IBSs are characterized by higher T_c (up to 37 K) and T_m (∼15 to 20 K) compared to other magnetic superconductors. The coexistence of superconductivity and magnetism extends over a wider range of temperatures and magnetic fields, allowing us to conduct experiments using various probes. For example, in the case of EuFe₂(As,P)₂ (6) and Eu(Fe,Rh)₂As₂ (7), where the Eu²⁺ moments exhibit ferromagnetic ordering, observations of a spontaneous vortex state, the domain Meissner state, and a vortex-antivortex state were reported using magnetic force microscopy (8) and magnetization measurements (9). Furthermore, for EuRbFe₄As₄ (10, 11) with a Eu²⁺ helical order (12), it was proposed that the Eu-spin subsystem serves as an internal pump for the magnetic flux based on magneto-optical imaging results (13, 14). In addition, optical conductivity measurements (15) and scanning Hall microscopy (16) revealed that the temperature dependence of the superfluid density shows a dip feature around T_m, which was attributed to the weakening of superconductivity at the magnetic transition.Most of these peculiar phenomena in magnetic superconductors are considered to reflect the impact of magnetism on superconductivity. On the contrary, an example of the influence of superconductivity on magnetism is the shrinkage of magnetic domains associated with the superconducting transition (17), which is favorable for superconductivity, as it reduces the internal magnetic field. Meanwhile, in a type-II superconductor, the magnetic flux penetrates the material, and the mixed state is generated. Once vortices are pinned, the superconductor can act as a magnet (known as a trapped-field magnet). In this situation, magnetism is likely influenced by the magnetic field generated by superconductivity. For example, the manipulation of local moments via superconducting vortices has been proposed using superconductor–magnet hybrids (18). To further investigate the impact of pinned vortices on the local moments, a superconductor with strong pinning properties is considered as a suitable target.The IBSs, especially the 122, 1111, and 1144 types, are known to show high critical current densities (J_c) of ∼1 MA/cm²; that is, they have a strong vortex pinning ability (19–26). Based on Bean’s critical state model (27), J_c is proportional to the gradient of the magnetic flux density (μ₀J_c = |dB/dx|). Then, when an IBS with a sample width (t) of 0.1 mm is magnetized in an external field, a large number of vortices are pinned and a strong magnetic field (H_sc = J_ct/2) of ∼5 kOe is estimated to be generated at the center of the sample. Therefore, in the case of Eu-IBSs, the superconductivity and the magnetic subsystem are both a source of strong magnetic fields; consequently, a nontrivial situation, where the magnetic fields generated by each state mutually affect each other, is considered. In this context, EuRbFe₄As₄ with the highest T_c among Eu-IBSs is an optimal material to investigate the influence of superconductivity on magnetism.Fig. 1A shows the crystal structure of EuRbFe₄As₄. Since the Eu and Rb layers are alternately stacked without a solid solution, the Eu layer spacing is approximately twice that of EuFe₂As₂. Fig. 1B illustrates the temperature dependence of the magnetic susceptibility, showing a sharp superconducting transition at T_c = 37 K with perfect diamagnetism at zero-field cooling (ZFC). The kink structure at T_m = 15 K found below T_c corresponds to the magnetic ordering of the Eu²⁺ moments. The arrows in Fig. 1A indicate the direction of the Eu²⁺ moments. In the ordered state, the Eu²⁺ moments align ferromagnetically in the ab plane, and the orientation of the ferromagnetic alignment rotates by 90° in the next layer; that is, the ground state is a helical order (12). Meanwhile, magnetization measurements showed that the Eu²⁺ moments are reoriented to the ferromagnetic alignment at relatively low external fields (the saturation field [H_sat] is estimated to be ∼2 kOe) (28). In the ferromagnetically aligned state, the internal field (H_Eu) calculated from the Eu²⁺ moments (7 μ_B/Eu) is ∼4.5 kOe, which is approximately half of that in EuFe₂As₂, reflecting the Eu layer spacing.Open in a separate windowFig. 1.Crystal structure and magnetic ordering of EuRbFe₄As₄. (A) Crystal structure of EuRbFe₄As₄. Blue arrows indicate the direction of the Eu²⁺ moments. The schematic diagram of the helical magnetic structure is shown on the Right. (B) Temperature dependence of the magnetization of a EuRbFe₄As₄ single crystal measured for ZFC and field-cooling processes. A magnetic field of 10 Oe was applied along the ab plane. The Inset shows a photograph of a EuRbFe₄As₄ single crystal with a black scale bar corresponding to 1 mm.Thus, in EuRbFe₄As₄, the magnitudes of the characteristic magnetic fields related to superconductivity and magnetism, that is, H_sc, H_Eu, and H_sat, are comparable to each other, such that the Eu²⁺ moments cannot neglect the influence arising from superconductivity. In principle, it is possible to control the arrangement of local Eu²⁺ moments using H_sc. Moreover, because the internal field generated by superconducting currents has spatial distributions, the direction of the Eu²⁺ moments is expected to be locally manipulable by controlling the magnetic field profile. In this study, we demonstrate that 1) the orientation of the Eu²⁺ moments in magnetic fields is dominated by the direction of pinned vortices, and 2) the domain structure of the Eu²⁺ moments can be manipulated by the distribution of superconducting vortices.     

Leg ulcers and abscesses caused by Serratia marcescens

Cutaneous infections caused by S. marcescens, a gram-negative bacillus belonging to the family of Enterobacteriaceae, are uncommon but may be predisposed by immunocompromised conditions or pre-damaged skin. A 73-year-old man presented with multiple ulcers and painful nodules on the lower right leg as well as abscesses on the right malleolus lateralis. He had been treated with oral penicillin without success. Due to chronic obstructive pulmonary disease, he was receiving a systemic therapy with corticosteroids. In addition, he had a post-thrombotic syndrome of the lower right leg. Serratia marcescens was the only microorganism isolated from all cultures performed. After a microbial sensitivity test, ertapenem 1 g/day was given intravenously for 10 days, followed by oral administration of ciprofloxacin 500 mg 1-0-1 for a further 7 days. This therapy resulted in the resolution of all lesions. This rare skin infection with S. marcescens needs specific microbiological diagnosis and adapted antibiosis.     

The average age of smoking onset in Germany – trends and correlates

Summary Objectives:  Germany is rated among the countries with the highest prevalence of tobacco use in Europe. This paper analyzes whether the age of smoking onset has decreased in recent years. Methods:  Multivariable event data analyses were performed on the basis of the representative national cross-sectional study “Drug Affinity among Young People in the Federal Republic of Germany 2004”. The survey involved a total net sample of 3032 individuals aged 12 to 25. Results:  Socioeconomic groups starting to smoke at significantly earlier age include those from the economically deprived areas in eastern Germany, low educational achievers and subjects in households with adult smokers. Conclusions:  The average age of smoking onset has decreased further in the 1978–1992 birth cohorts. Submitted: 18 November 2006; Revised: 23 January 2008, 18 March 2008; Accepted: 19 March 2008     

Microcarrier-based MDCK cell culture system for the production of influenza H5N1 vaccines

Current egg-based influenza vaccine production technology, which is labor intensive and slow, would not be able to meet demand during an influenza pandemic. Thus, interest in the emerging technology of using mammalian cells for vaccine production has been great. In this study, Madin-Darby canine kidney (MDCK) cells using microcarrier culture systems were established to produce inactivated whole-virus H5N1 vaccine. The current clade-1 influenza H5N1 vaccine virus (NIBRG-14) was provided by the UK National Institute for Biological Standards and Control. Various process parameters were first optimized in 100-mL scale spinner flasks then scaled up to a 1-L scale bioreactor system. In the 1-L scale bioreactor system, peak virus titer could reach 10(8-9)TCID50/mL using serum-containing medium. After purification and inactivation, hemagglutinin (HA) protein content reached 31.56-43.96 microg/mL in two different runs. In mice immunogenicity studies, two doses of the purified vaccine antigen adjuvanted with aluminum phosphate induced good immune responses in 0.2 and 1.0 microg HA dosages (geometric mean titers of hemagglutination-inhibition antibody: 113 and 242, respectively). This study demonstrates the feasibility of the development of MDCK cell-based inactivated influenza H5 vaccines in microcarrier culture systems and could be valuable to many countries that are planning to establish manufacturing capacity for influenza vaccines.     

ASH1L (a histone methyltransferase protein) is a novel candidate globin gene regulator revealed by genetic study of an English family with beta‐thalassaemia unlinked to the beta‐globin locus

In 1993, we described an English family with beta‐thalassaemia that was not linked to the beta‐globin locus. Whole genome sequence analyses revealed potential causative mutations in 15 different genes, of which 4 were consistently and uniquely associated with the phenotype in all 7 affected family members, also confirmed by genetic linkage analysis. Of the 4 genes, which are present in a centromeric region of chromosome 1, ASH1L was proposed as causative through functional mRNA knock‐down and chromatin‐immunoprecipitation studies in human erythroid progenitor cells. Our data suggest a putative role for ASH1L (Trithorax protein) in the regulation of globin genes.