Vacancies in electron irradiated 6H silicon carbide studied by positron annihilation spectroscopy

Paper no. R3.19Positron lifetime spectroscopy was employed to study the as-electron-irradiated (10 MeV, 1×10 18 cm -2) n-type 6H silicon carbide sample in the measuring temperature range of 15 K to 294 K. Isochronal annealing studies were also performed up to the temperature of 1373 K by carrying out the room temperature positron lifetime measurement. Negatively charged carbon vacancies and V cV si divacancy were identified as the major vacancy type defects induced by the electron irradiation process. The concentration of the V cV si divacancy was found to decrease dramatically after the 1973 K annealing.published_or_final_versio

CARMA1 is a novel regulator of T-ALL disease and leukemic cell migration to the CNS

No abstract available

Transplanted Olfactory Ensheathing Cells Reduce Retinal Degeneration in Royal College of Surgeons Rats

PURPOSE OF THE STUDY: Retinitis pigmentosa (RP) is a group of genetic disorders and a slow loss of vision that is caused by a cascade of retinal degenerative events. We examined whether these retinal degenerative events were reduced after cultured mixtures of adult olfactory ensheathing cells (OECs) and olfactory nerve fibroblasts (ONFs) were transplanted into the subretinal space of 1-month-old RCS rat, a classic model of RP. MATERIALS AND METHODS: The changes in retinal photoreceptors and Müller cells of RCS rats after cell transplantation were observed by the expression of recoverin and glial fibrillary acidic protein (GFAP), counting peanut agglutinin (PNA)-positive cone outer segments and calculating the relative apoptotic area. The retinal function was also evaluated by Flash electroretinography (ERG). To further investigate the mechanisms, by which OECs/ONFs play important roles in the transplanted retinas, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and basic fibroblast growth factor (bFGF) secretion of the cultured cells were analyzed by ELISA. The ability of OECs/ONFs to ingest porcine retinal outer segments and the amount of phagocytosis were compared with retinal pigment epithelium (RPE) cells. RESULTS: Our research showed that the transplantation of OECs/ONFs mixtures restored recoverin expression, protected retinal outer segments, increased PNA-positive cone outer segments, reduced caspase-positive apoptotic figures, downregulated GFAP, and maintained the b-wave of the ERG. Cultured OECs/ONFs expressed and secreted NGF, BDNF, and bFGF which made contributions to assist survival of the photoreceptors. An in vitro phagocytosis assay showed that OECs, but not ONFs, phagocytosed porcine retinal outer segments, and the phagocytic ability of OECs was even superior to that of RPE cells. CONCLUSIONS: These findings demonstrate that transplantation of OECs/ONFs cleaned up the accumulated debris in subretinal space, and provided an intrinsic continuous supply of neurotrophic factors. It suggested that transplantation of OECs/ONFs might be a possible future route for protection of the retina and reducing retinal degeneration in RP

Correlation Between Previous Caesarean Section and Adverse Maternal Outcomes Accordingly With Robson Classification: Systematic Review and Meta-Analysis

Background: The increasing rates of Caesarean section (CS) beyond the WHO standards (10–15%) pose a significant global health concern. Objective: Systematic review and meta-analysis to identify an association between CS history and maternal adverse outcomes for the subsequent pregnancy and delivery among women classified in Robson classification (RC). Search Strategy: PubMed/Medline, EbscoHost, ProQuest, Embase, Web of Science, BIOSIS, MEDLINE, and Russian Science Citation Index databases were searched from 2008 to 2018. Selection Criteria: Based on Robson classification, studies reporting one or more of the 14 adverse maternal outcomes were considered eligible for this review. Data Collection: Study design data, interventions used, CS history, and adverse maternal outcomes were extracted. Main Results: From 4,084 studies, 28 (n = 1,524,695 women) met the inclusion criteria. RC group 5 showed the highest proportion among deliveries followed by RC10, RC7, and RC8 (67.71, 32.27, 0.02, and 0.001%). Among adverse maternal outcomes, hysterectomy had the highest association after preterm delivery OR = 3.39 (95% CI 1.56–7.36), followed by Severe Maternal Outcomes OR = 2.95 (95% CI 1.00–8.67). We identified over one and a half million pregnant women, of whom the majority were found to belong to RC group 5. Conclusions: Previous CS was observed to be associated with adverse maternal outcomes for the subsequent pregnancies. CS rates need to be monitored given the prospective risks which may occur for maternal and child health in subsequent births

Spinons and triplons in spatially anisotropic frustrated antiferromagnets

The search for elementary excitations with fractional quantum numbers is a central challenge in modern condensed matter physics. We explore the possibility in a realistic model for several materials, the spin-1/2 spatially anisotropic frustrated Heisenberg antiferromagnet in two dimensions. By restricting the Hilbert space to that expressed by exact eigenstates of the Heisenberg chain, we derive an effective Schr\"odinger equation valid in the weak interchain-coupling regime. The dynamical spin correlations from this approach agree quantitatively with inelastic neutron measurements on the triangular antiferromagnet Cs_2CuCl_4. The spectral features in such antiferromagnets can be attributed to two types of excitations: descendents of one-dimensional spinons of individual chains, and coherently propagating "triplon" bound states of spinon pairs. We argue that triplons are generic features of spatially anisotropic frustrated antiferromagnets, and arise because the bound spinon pair lowers its kinetic energy by propagating between chains.Comment: 16 pages, 6 figure

X-ray Absorption Near-Edge Structure calculations with pseudopotentials. Application to K-edge in diamond and alpha-quartz

We present a reciprocal-space pseudopotential scheme for calculating X-ray absorption near-edge structure (XANES) spectra. The scheme incorporates a recursive method to compute absorption cross section as a continued fraction. The continued fraction formulation of absorption is advantageous in that it permits the treatment of core-hole interaction through large supercells (hundreds of atoms). The method is compared with recently developed Bethe-Salpeter approach. The method is applied to the carbon K-edge in diamond and to the silicon and oxygen K-edges in alpha-quartz for which polarized XANES spectra were measured. Core-hole effects are investigated by varying the size of the supercell, thus leading to information similar to that obtained from cluster size analysis usually performed within multiple scattering calculations.Comment: 11 pages, 4 figure

UPF1, a Conserved Nonsense-Mediated mRNA Decay Factor, Regulates Cyst Wall Protein Transcripts in Giardia lamblia

The Giardia lamblia cyst wall is required for survival outside the host and infection. Three cyst wall protein (cwp) genes identified to date are highly up-regulated during encystation. However, little is known of the molecular mechanisms governing their gene regulation. Messenger RNAs containing premature stop codons are rapidly degraded by a nonsense-mediated mRNA decay (NMD) system to avoid production of non-functional proteins. In addition to RNA surveillance, NMD also regulates thousands of naturally occurring transcripts through a variety of mechanisms. It is interesting to know the NMD pathway in the primitive eukaryotes. Previously, we have found that the giardial homologue of a conserved NMD factor, UPF1, may be functionally conserved and involved in NMD and in preventing nonsense suppression. In this study, we tested the hypothesis that NMD factors can regulate some naturally occurring transcripts in G. lamblia. We found that overexpression of UPF1 resulted in a significant decrease of the levels of CWP1 and cyst formation and of the endogenous cwp1-3, and myb2 mRNA levels and stability. This indicates that NMD could contribute to the regulation of the cwp1-3 and myb2 transcripts, which are key to G. lamblia differentiation into cyst. Interestingly, we also found that UPF1 may be involved in regulation of eight other endogenous genes, including up-regulation of the translation elongation factor gene, whose product increases translation which is required for NMD. Our results indicate that NMD factor could contribute to the regulation of not only nonsense containing mRNAs, but also mRNAs of the key encystation-induced genes and other endogenous genes in the early-diverging eukaryote, G. lamblia

Ecosystem-Driven Design of In-Home Terminals Based on Open Platform for the

Abstract—In-home healthcare services based on the Internet-of-Things (IoT) have great business potentials. To turn it into reality, a business ecosystem should be established first. Technical solutions should therefore aim for a cooperative ecosystem by meeting the interoperability, security, and system integration requirements. In this paper, we propose an ecosystem-driven design strategy and apply it in the design of an open-platform-based in-home healthcare terminal. A cooperative business ecosystem is formulated by merging the traditiona