113 research outputs found
Deconfinement of Vortices with Continuously Variable Fractions of the Unit Flux Quanta in Two-Gap Superconductors
We propose a new stage of confiment-decofinment transition, which can be
observed in laboratory. In two-gap superconductors (SCs), two kinds of vortex
exist and each of them carries a continuously variable fraction of the unit
flux quanta Phi_0=h c / 2 e. The confined state of these two is a usual vortex
and stable in the low temperature region of the system under a certain magnetic
field above H_c1. We see an analogy to quarks in a charged pion. An entropy
gain causes two fractional vortices to be deconfined above a certain
temperature.Comment: 5 pages, 3 figures, to be published in Europhys. Let
Successful laparoscopic resection of virilizing ovarian steroid cell tumor, not otherwise specified, in a 22-year-old woman: a case report and evaluation of the steroidogenic pathway
Objective: Ovarian steroid cell tumor (SCT) is a rare tumor with steroid-producing ability. We report a 22-year-old woman with secondary amenorrhea and hirsutism caused by an ovarian SCT-not otherwise specified (NOS), who underwent successfully laparoscopic resection of the tumor. Case report: A 22-year-old null gravida woman presented to a hospital, having amenorrhea for 18 months and increasing facial hair. Physical examination revealed obesity (body mass index, 37.3 kg/m2) with evident facial and trunk hair. Total and free serum testosterone, and dehydroepiandrosterone sulfate levels were found to be elevated. Levels of serum adrenocorticotropic hormone, gonadotropins, cortisol, aldosterone, and ovarian steroids were observed to be within reference intervals. Although polycystic ovaries were not found, a hyperechogenic solid tumor (3 cm) was detected on transvaginal ultrasonography. Laparoscopic resection of the tumor was performed. One month post-surgery, total and free testosterone levels were observed to have decreased, and menstruation resumed two months thereafter. The patient was histologically diagnosed with ovarian SCT-NOS. Expression of ovarian steroidogenic enzymes, which are related to hyperandrogenism, was observed. No disease recurrence has been reported for more than 5 years post-surgery
Competition between magnetic interactions and structural instabilities leading to itinerant frustration in the triangular lattice antiferromagnet LiCrSe2
LiCrSe2 constitutes a recent valuable addition to the ensemble of two-dimensional triangular lattice antiferromagnets. In this work, we present a comprehensive study of the low temperature nuclear and magnetic structure established in this material. Being subject to a strong magnetoelastic coupling, LiCrSe2 was found to undergo a first order structural transition from a trigonal crystal system (P3 \uaf m1) to a monoclinic one (C2/m) at T s = 30 K. Such restructuring of the lattice is accompanied by a magnetic transition at T N = 30 K. Refinement of the magnetic structure with neutron diffraction data and complementary muon spin rotation analysis reveal the presence of a complex incommensurate magnetic structure with a up-up-down-down arrangement of the chromium moments with ferromagnetic double chains coupled antiferromagnetically. The spin axial vector is also modulated both in direction and modulus, resulting in a spin density wave-like order with periodic suppression of the chromium moment along the chains. This behavior is believed to appear as a result of strong competition between direct exchange antiferromagnetic and superexchange ferromagnetic couplings established between both nearest neighbor and next nearest neighbor Cr3+ ions. We finally conjecture that the resulting magnetic order is stabilized via subtle vacancy/charge order within the lithium layers, potentially causing a mix of two co-existing magnetic phases within the sample
Nonsurgical Interventions to Prevent Disease Progression in Prostate Cancer Patients on Active Surveillance: A Systematic Review and Meta-analysis
CONTEXT: Active surveillance (AS) is a standard of care for patients with low-risk and selected intermediate-risk prostate cancer (PCa). Nevertheless, there is a lack of summary evidence on how to impact disease trajectory during AS. OBJECTIVE: To assess which interventions prevent PCa progression effectively during AS. EVIDENCE ACQUISITION: We queried PubMed, Scopus, and Web of Science databases to identify studies examining the impact of interventions aimed at slowing disease progression during AS. The primary endpoint was PCa progression, the definition of which must have included pathological upgrading. The secondary endpoint included treatment toxicities. EVIDENCE SYNTHESIS: We identified 22 studies, six randomized controlled trials and 16 observational studies, which analyzed the association between different interventions and PCa progression during AS. The interventions considered in the studies included 5-alpha reductase inhibitors (5-ARIs), statins, diet, exercise, chlormadinone, fexapotide triflutate (FT), enzalutamide, coffee, vitamin D3, and PROSTVAC. We found that administration of 5-ARIs was associated with improved progression-free survival (PFS; hazard ratio: 0.59; 95% confidence interval 0.48-0.72), with no increased toxicity signals. Therapies such as vitamin D3, chlormadinone, FT, and enzalutamide have shown some efficacy. However, these anticancer drugs have been associated with treatment-related adverse events in up to 88% of patients. CONCLUSIONS: The use of 5-ARIs in PCa patients on AS is associated with longer PFS. However, for the other interventions, it is difficult to draw clear conclusions based on the weak available evidence. PATIENT SUMMARY: Patients with prostate cancer managed with active surveillance (AS) who are treated with 5-alpha reductase inhibitors have a lower risk of disease progression, with minimal adverse events. Other interventions require more studies to determine their efficacy and safety profile in men on AS
Identification of novel SNPs of ABCD1, ABCD2, ABCD3, and ABCD4 genes in patients with X-linked adrenoleukodystrophy (ALD) based on comprehensive resequencing and association studies with ALD phenotypes
Adrenoleukodystrophy (ALD) is an X-linked disorder affecting primarily the white matter of the central nervous system occasionally accompanied by adrenal insufficiency. Despite the discovery of the causative gene, ABCD1, no clear genotype–phenotype correlations have been established. Association studies based on single nucleotide polymorphisms (SNPs) identified by comprehensive resequencing of genes related to ABCD1 may reveal genes modifying ALD phenotypes. We analyzed 40 Japanese patients with ALD. ABCD1 and ABCD2 were analyzed using a newly developed microarray-based resequencing system. ABCD3 and ABCD4 were analyzed by direct nucleotide sequence analysis. Replication studies were conducted on an independent French ALD cohort with extreme phenotypes. All the mutations of ABCD1 were identified, and there was no correlation between the genotypes and phenotypes of ALD. SNPs identified by the comprehensive resequencing of ABCD2, ABCD3, and ABCD4 were used for association studies. There were no significant associations between these SNPs and ALD phenotypes, except for the five SNPs of ABCD4, which are in complete disequilibrium in the Japanese population. These five SNPs were significantly less frequently represented in patients with adrenomyeloneuropathy (AMN) than in controls in the Japanese population (p = 0.0468), whereas there were no significant differences in patients with childhood cerebral ALD (CCALD). The replication study employing these five SNPs on an independent French ALD cohort, however, showed no significant associations with CCALD or pure AMN. This study showed that ABCD2, ABCD3, and ABCD4 are less likely the disease-modifying genes, necessitating further studies to identify genes modifying ALD phenotypes
Modulation of radial blood flow during Braille character discrimination task
Purpose: Human hands are excellent in performing sensory and motor function. We have hypothesized that blood flow of the hand is dynamically regulated by sympathetic outflow during concentrated finger perception. To identify this hypothesis, we measured radial blood flow (RBF), radial vascular conductance (RVC), heart rate (HR), and arterial blood pressure (AP) during Braille reading performed under the blind condition in nine healthy subjects. The subjects were instructed to read a flat plate with raised letters (Braille reading) for 30 s by the forefinger, and to touch a blank plate as control for the Braille discrimination procedure. Results: HR and AP slightly increased during Braille reading but remained unchanged during the touching of the blank plate. RBF and RVC were reduced during the Braille character discrimination task (decreased by -46% and -49%, respectively). Furthermore, the changes in RBF and RVC were much greater during the Braille character discrimination task than during the touching of the blank plate (decreased by -20% and -20%, respectively). Conclusions: These results have suggested that the distribution of blood flow to the hand is modulated via sympathetic nerve activity during concentrated finger perception
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