823 research outputs found
Curvature-induced spin-orbit coupling and spin relaxation in a chemically clean single-layer graphene
The study of spin-related phenomena in materials requires knowledge on the
precise form of effective spin-orbit coupling of conducting carriers in the
solid-states systems. We demonstrate theoretically that curvature induced by
corrugations or periodic ripples in single-layer graphenes generates two types
of effective spin-orbit coupling. In addition to the spin-orbit coupling
reported previously that couples with sublattice pseudospin and corresponds to
the Rashba-type spin-orbit coupling in a corrugated single-layer graphene,
there is an additional spin-orbit coupling that does not couple with the
pseudospin, which can not be obtained from the extension of the
curvature-induced spin-orbit coupling of carbon nanotubes. Via numerical
calculation we show that both types of the curvature-induced spin-orbit
coupling make the same order of contribution to spin relaxation in chemically
clean single-layer graphene with nanoscale corrugation. The spin relaxation
dependence on the corrugation roughness is also studied.Comment: 8 pages, 4 figure
The cap-snatching SFTSV endonuclease domain is an antiviral target
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tick-borne virus with 12%-30% case mortality rates and is related to the Heartland virus (HRTV) identified in the United States. Together, SFTSV and HRTV are emerging segmented, negative-sense RNA viral (sNSV) pathogens with potential global health impact. Here, we characterize the amino-terminal cap-snatching endonuclease domain of SFTSV polymerase (L) and solve a 2.4-Å X-ray crystal structure. While the overall structure is similar to those of other cap-snatching sNSV endonucleases, differences near the C terminus of the SFTSV endonuclease suggest divergence in regulation. Influenza virus endonuclease inhibitors, including the US Food and Drug Administration (FDA) approved Baloxavir (BXA), inhibit the endonuclease activity in in vitro enzymatic assays and in cell-based studies. BXA displays potent activity with a half maximal inhibitory concentration (I
Incidence of Capillary Leak Syndrome as an Adverse Effect of Drugs in Cancer Patients: A Systematic Review and Meta-Analysis
Capillary leak syndrome (CLS) is a rare disease with profound vascular leakage, which can be associated with a high mortality. There have been several reports on CLS as an adverse effect of anti-cancer agents and therapy, but the incidence of CLS according to the kinds of anti-cancer drugs has not been systemically evaluated. Thus, the aim of our study was to comprehensively meta-analyze the incidence of CLS by different types of cancer treatment or after bone marrow transplantation (BMT). We searched the literatures (inception to July 2018) and among 4612 articles, 62 clinical trials (studies) were eligible. We extracted the number of patients with CLS, total cancer patients, name of therapeutic agent and dose, and type of cancer. We performed a meta-analysis to estimate the summary effects with 95% confidence interval and between-study heterogeneity. The reported incidence of CLS was categorized by causative drugs and BMT. The largest number of studies reported on CLS incidence during interleukin-2 (IL-2) treatment (n = 18), which yielded a pooled incidence of 34.7% by overall estimation and 43.9% by meta-analysis. The second largest number of studies reported on anti-cluster of differentiation (anti-CD) agents (n = 13) (incidence of 33.9% by overall estimation and 35.6% by meta-analysis) or undergoing BMT (n = 7 (21.1% by overall estimation and 21.7% by meta-analysis). Also, anti-cancer agents, including IL-2 + imatinib mesylate (three studies) and anti-CD22 monoclinal antibodies (mAb) (four studies), showed a dose-dependent increase in the incidence of CLS. Our study is the first to provide an informative overview on the incidence rate of reported CLS patients as an adverse event of anti-cancer treatment. This meta-analysis can lead to a better understanding of CLS and assist physicians in identifying the presence of CLS early in the disease course to improve the outcome and optimize management
Physiological properties of astroglial cell lines derived from mice with high (SAMP8) and low (SAMR1, ICR) levels of endogenous retrovirus
Previous studies have reported that various inbred SAM mouse strains differ markedly with regard to a variety of parameters, such as capacity for learning and memory, life spans and brain histopathology. A potential cause of differences seen in these strains may be based on the fact that some strains have a high concentration of infectious murine leukemia virus (MuLV) in the brain, whereas other strains have little or no virus. To elucidate the effect of a higher titer of endogenous retrovirus in astroglial cells of the brain, we established astroglial cell lines from SAMR1 and SAMP8 mice, which are, respectively, resistant and prone to deficit in learning and memory and shortened life span. MuLV-negative astroglial cell lines established from ICR mice served as controls. Comparison of these cell lines showed differences in: 1) levels of the capsid antigen CAgag in both cell lysates and culture media, 2) expression of genomic retroelements, 3) the number of virus particles, 4) titer of infectious virus, 5) morphology, 6) replication rate of cells in culture and final cell concentrations, 7) expression pattern of proinflammatory cytokine genes. The results show that the expression of MuLV is much higher in SAMP8 than SAMR1 astrocyte cultures and that there are physiological differences in astroglia from the 2 strains. These results raise the possibility that the distinct physiological differences between SAMP8 and SAMR1 are a function of activation of endogenous retrovirus
Effect of renal Doppler ultrasound on the detection of nutcracker syndrome in children with hematuria
To assess the detection rate of nutcracker syndrome in children with isolated hematuria, renal Doppler ultrasound examinations were routinely performed on 216 consecutive children (176 microscopic hematuria and 40 gross hematuria). Renal Doppler ultrasound was also performed on 32 healthy normal children. The peak velocity (PV) was measured at the hilar portion of the left renal vein (LRV) and at the LRV between the aorta and the superior mesenteric artery. The PV at the aortomesenteric portion (P=0.003) and the PV ratios of the LRV (P=0.003) were significantly higher in children with hematuria than in normal children, while the PV at the hilar portion was not different. If a PV ratio of the LRV of at least 4.1 (the cut-off level set at the mean ±2 SD of the value for the normal children) was defined as abnormal, 72 cases (33.3%) in children with hematuria and no cases in normal children were diagnosed as having nutcracker syndrome. The prevalence of nutcracker syndrome is relatively high in children with isolated hematuria, and the inclusion of renal Doppler ultrasound as a screening examination has a substantial effect on the detection of nutcracker syndrome
Burden of Human papillomavirus (HPV)-related disease and potential impact of HPV vaccines in the Republic of Korea
Background: We aimed to review the burden and the potential impact of human papillomavirus (HPV) vaccines on HPV-related diseases in the Republic of Korea and to discuss cervical cancer prevention practices in this country. Methods: Cancer burden statistics were retrieved from GLOBOCAN-2018 and Statistics Korea. HPV disease burden was assessed via systematic review. Vaccine types relative contribution (RC) was estimated using data from an international project using formalin-fixed paraffin-embedded specimens. Results: Despite a downtrend in cervical cancer in recent years, Korean rates remain high. In contrast, oropharyngeal cancer incidence has gradually increased and other anogenital cancers remain rare. In Korea, HPV prevalence in general population is around 20%. In cervical cancer, RC of HPVs 16/18 (74.0%) increased to 92.0% when including HPVs 31/33/45/52/58. Limited information was available for other HPV-related cancer sites. Regarding prevention, since the inclusion of the HPV vaccine into the National Immunization Program, almost half (49%) of the target cohort in 2016 had received the first dose of vaccine. Further, percentage of women screened with pap has increased from 41.1%-2009 to 53.0%-2016. Conclusions: HPV-related disease burden in Korea is significant. Results suggest that the combination of effective and high coverage HPV vaccination and screening programmes could substantially impact on HPV-related disease in Korea
Association between autism spectrum disorder and diabetes: systematic review and meta-analysis
There is mixed evidence on the link between autism spectrum disorder (ASD) and diabetes. We conducted the first systematic review/meta-analysis on their association. Based on a pre-registered protocol (PROSPERO: CRD42021261114), we searched Pubmed, Ovid, and Web of Science databases up to 6 December 2021, with no language/type of document restrictions. We assessed study quality using the Newcastle-Ottawa Scale (NOS). We included 24 studies (total: 3427,773 individuals; 237,529 with ASD and 92,832 with diabetes) in the systematic review and 20 in the meta-analysis (mean stars number on the NOS: 5.89/10). There was a significant association, albeit characterized by significant heterogeneity, when pooling unadjusted OR (1.535, 95% CI = 1.109-2.126), which remained significant when restricting the analysis to children and type 2 diabetes, but became non-significant when considering adjusted ORs (OR: 1.528, 95% CI = 0.954-2.448). No significant prospective association was found (n = 2) on diabetes predicting ASD (HR: 1.232, 0.826-11.837). Therefore, the association between ASD and diabetes is likely confounded by demographic and clinical factors that should be systematically investigated in future studies
Beneficial and Adverse Effects of Bosentan Treatment in Korean Patients With Pulmonary Artery Hypertension
Background and Objectives: The purpose of this study was to investigate 1) the beneficial effect of bosentan treatment (125 mg twice daily) on exercise capacity and echocardiographic variables and 2) the profiles and frequency of adverse events in Korean patients with World Health Organization (WHO) class III or IV pulmonary artery hypertension (PAH). Subjects and Methods: Twelve patients who received bosentan treatment were investigated in an open label manner. One patient was excluded in the final analyses due to a prohibited concomitant medication. A 6-minute walk test and echocardiography were performed at baseline and after 12 weeks of treatment. Results: The administration of bosentan for 12 weeks resulted in a significant improvement in exercise capacity (measured with the 6-minute walking distance), WHO functional capacity, and in echocardiographic variables. Bosentan treatment was associated with a decrease in the maximal tricuspid regurgitation jet velocity {from 4.7 m/sec (95% confidence interval, 3.89-5.45) at baseline to 4.4 m/sec (95% confidence interval, 3.61-5.1) at 12 weeks, p=0.03} and systolic pulmonary arterial pressure {from 105 mmHg (95% confidence interval, 74.4-135.6) at baseline to 93 mmHg (95% confidence interval, 66.3-120.1) at 12 weeks, p=0.04}. Treatment with bosentan at a dose of 125 mg twice a day was not associated with life-threatening side effects, although a higher incidence of elevated liver enzymes compared to previous studies was noted. Conclusion: Bosentan at a dose of 125 mg twice daily is considered a clinically optimal, safe dose and can be used as a valuable treatment option in Korean PAH patients with WHO functional capacity III or IV, though close monitoring of liver function is required. Copyright �� 2009 The Korean Society of Cardiology
Electron energy increase in a laser wakefield accelerator using up-ramp plasma density profiles
The phase velocity of the wakefield of a laser wakefield accelerator can, theoretically, be manipulated by shaping the longitudinal plasma density profile, thus controlling the parameters of the generated electron beam. We present an experimental method where using a series of shaped longitudinal plasma density profiles we increased the mean electron peak energy more than 50%, from 175 +/- 1 MeV to 262 +/- 10 MeV and the maximum peak energy from 182 MeV to 363 MeV. The divergence follows closely the change of mean energy and decreases from 58.9 +/- 0.45 mrad to 12.6 +/- 1.2 mrad along the horizontal axis and from 35 +/- 0.3 mrad to 8.3 +/- 0.69 mrad along the vertical axis. Particle-in-cell simulations show that a ramp in a plasma density profile can affect the evolution of the wakefield, thus qualitatively confirming the experimental results. The presented method can increase the electron energy for a fixed laser power and at the same time offer an energy tunable source of electrons.© The Author(s) 201
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