Influence of Cu Content on Structure,Thermal Stability and Magnetic Properties in Fe72−xNi8Nb4CuxSi2B14 Alloys

The effect of substitution of Fe by Cu on the crystal structure and magnetic properties of Fe_72−xNi₈Nb₄Cu_xSi₂B₁₄ alloys (x = 0.6, 1.1, 1.6 at.%) in the form of ribbons was investigated. The chemical composition of the materials was established on the basis of the calculated minima of thermodynamic parameters: Gibbs free energy of amorphous phase formation ΔG^amorph (minimum at 0.6 at.% of Cu) and Gibbs free energy of mixing ΔG^mix (minimum at 1.6 at.% of Cu). The characteristic crystallization temperatures T_x1onset and T_x1 of the alpha-iron phase together with the activation energy E_a for the as-spun samples were determined by differential scanning calorimetry (DSC) with a heating rate of 10–100 °C/min. In order to determine the optimal soft magnetic properties, the wound cores were subjected to a controlled isothermal annealing process in the temperature range of 340–640 °C for 20 min. Coercivity Hc, saturation induction Bs and core power losses at B = 1 T and frequency f = 50 Hz P_10/50 were determined for all samples. Moreover, for the samples with the lowest Hc and P_10/50, the magnetic losses were determined in a wider frequency range 50 Hz–400 kHz. The real and imaginary parts of the magnetic permeability µ′, µ″ along with the cut-off frequency were determined for the samples annealed at 360, 460, and 560 °C. The best soft magnetic properties (i.e., the lowest value of Hc and P_10/50) were observed for samples annealed at 460 °C, with Hc = 4.88–5.69 A/m, Bs = 1.18–1.24 T, P_10/50 = 0.072–0.084 W/kg, µ′ = 8350–10,630 and cutoff frequency at 8–9.3 × 10⁴ Hz. The structural study of as-spun and annealed ribbons was carried out using X-ray diffraction (XRD) and a transmission electron microscope (TEM).     

Molecular organisation of an A mating type factor of the basidiomycete fungus Coprinus cinereus

Summary The A3 and A3 genes, which together constitute the A42 mating type factor of Coprinus cinereus, were isolated from a cosmid genomic library by walking 50 kb, a map distance of 0.5 units, from the closely linked metabolic gene pab-1. Cosmid clones having A gene function were identified by transformation into compatible A6 (22) and A5 (11) host cells where either 3 or 3 was expected to elicit the A factor — regulated development of unfused clamp cells. DNAs were digested with various enzymes before transformation in order to identify the smallest fragments containing an active 3 or 3 gene. Two non-overlapping fragments were identified as containing the 3 and 3 genes respectively. Southern hybridisation analyses showed that these two cloned genes had no detectable sequence homology, and that there was little or no hybridisation to the and gene alleles that constitute the A5 and A6 factors. 3 and 3 were shown to be less than 2.0 kb apart and embedded in a DNA sequence extending over 9.0 kb which was unique to our A42 strain and may contain a third A factor gene.     

Acute platelet response to aneurysmal subarachnoid hemorrhage depends on severity and distribution of bleeding: an observational cohort study

Neurosurgical Review - Microthrombosis after aneurysmal subarachnoid hemorrhage (aSAH) is considered to initiate neuroinflammation, vessel remodeling, and blood-brain barrier leakage. We aimed to...     

Synthesis of Dense MgB2 Superconductor via In Situ and Ex Situ Spark Plasma Sintering Method

In this study, high-density magnesium diboride (MgB₂) bulk superconductors were synthesized by spark plasma sintering (SPS) under pressure to improve the field dependence of the critical current density (J_c-B) in MgB₂ bulk superconductors. We investigated the relationship between sintering conditions (temperature and time) and J_c-B using two methods, ex situ (sintering MgB₂ synthesized powder) and in situ (reaction sintering of Mg and B powder), respectively. As a result, we found that higher density with suppressed particle growth and suppression of the formation of coarse particles of MgB₄ and MgO were found to be effective in improving the J_c-B characteristics. In the ex situ method, the degradation of MgB₂ due to pyrolysis was more severe at temperatures higher than 850 °C. The sample that underwent SPS treatment for a short time at 850 °C showed higher density and less impurity phase in the bulk, which improved the J_c-B properties. In addition, the in situ method showed very minimal impurity with a corresponding improvement in density and J_c-B characteristics for the sample optimized at 750 °C. Microstructural characterization and flux pinning (f_P) analysis revealed the possibility of refined MgO inclusions and MgB₄ phase as new pinning centers, which greatly contributed to the J_c-B properties. The contributions of the sintering conditions on f_P for both synthesis methods were analyzed.     

Pediatric arrowshot injury to cervical spinal cord-sagittal cord transection with no neurological deficit and good outcome: case report and review of literature

Background

Penetrating spinal cord injuries (PSCI) in cervical region are extremely rare in children. They mostly occur in a mechanism of a gunshot or a stab injury with the use of sharp objects. Gunshot injuries are usually fatal or end up with tetraplegia. Stab wounds may be less severe and result in partial neurological syndrome. In the management of PSCI in children, reliable diagnostics and history of the patient are the most valuable for further decisions, which include early or delayed exploration either nonsurgical treatment. There exist no clear algorithm for antibiotic use in pediatric population—it depends on the site of an injury, presence of pathological secretion from the wound, and nature of the trauma. The use of steroids is controversial. The most common complications related to surgery include infections, edema, and hemorrhage. They may also be associated with the migration of small residual microtraumatizing agent. The literature lacks algorithms for management in children.

Discussion

In this paper, an unusual case of almost total sagittal cervical cord transection is reported. The patient had no neurological symptoms and recovered with no complications. Diagnostic imaging on admission included X-ray and computed tomography. The patient underwent early surgical intervention with removal of foreign body from the cord and subsequent dural suturing. In the paper, the role of detailed history taking, adequate imaging, and drugs administration is discussed. The choice of distinct strategies is analyzed, and a revised literature review is presented in order to unify the management algorithm for pediatric PSCI.     

The combination of dissimilar alleles of the A alpha and A beta gene complexes, whose proteins contain homeo domain motifs, determines sexual development in the mushroom Coprinus cinereus.

The A mating-type factor is one of two gene complexes that allows mating cells of the mushroom Coprinus cinereus to recognize self from nonself and to regulate a pathway of sexual development that leads to meiosis and sporulation. We have identified seven A genes separated into two subcomplexes corresponding to the classical A alpha and A beta loci. Four genes, one alpha and three beta, all coding for proteins with a homeo domain-related motif, determine A-factor specificity; their allelic forms are so different in sequence that they do not cross-hybridize. It requires only one of these four genes to be heteroallelic in a cell to trigger A-regulated sexual development, and it is the different combinations of their alleles that generate the multiple A factors found in nature. The other three genes cause no change in cell morphology and may regulate the activity of the four specificity genes.     

Malignant melanoma of the plantar aspect of the foot

Malignant melanoma is the most frequently diagnosed malignant lesion of the foot. We present an overview of the diagnosis, classifications, and treatment of malignant melanoma. We report a case involving surgical intervention as well as treatment of postoperative skin slough with human amniotic membrane.     

Usefulness of the radiological planning for hearing preservation surgery in vestibular schwannoma

Purpose

During vestibular schwannoma surgery there is a risk of endolymphatic duct and sac injury, which may cause a loss or a deterioration of hearing. The goal of the study was to evaluate the empirical utility of presurgical planning using CT with the bone window for the hearing preservation surgery.

Methods

The study was performed on 14 human temporal bones. CT scans with the bone window were obtained in the standard position. Safe drilling line was evaluated and after that drilling distances were analysed: the lateral drilling distance, total length of internal acoustic meatus, drilled length of internal acoustic meatus. After this, a surgical exposure was performed, using size of a drill tip as measuring scale. The dura was excised and endolymphatic duct was injected with a latex. Revision of the internal acoustic meatus was performed with the use of a microscope.

Results

Mean results of safe drilling coefficients were: lateral drilling distance: 10 ± 2 mm, total length of internal acoustic meatus: 9 ± 2 mm, drilled length of internal acoustic meatus: 7 ± 2 mm. In all cases, no endolymphatic duct injury was observed.

Conclusions

Preoperative radiological planning using the safe drilling coefficients is of value for the hearing preservation surgery in vestibular schwannoma. The size of the drilling tip may be used as an intraoperative measuring scale during this procedure. However, CT with a bone window is a necessary tool for the purposes of this procedure.