D'yakonov-Perel' spin relaxation in InSb/AlInSb quantum wells

We investigate theoretically the D'yakonov-Perel' spin relaxation time by solving the eight-band Kane model and Poisson equation self-consistently. Our results show distinct behavior with the single-band model due to the anomalous spin-orbit interactions in narrow band-gap semiconductors, and agree well with the experiment values reported in recent experiment (K. L. Litvinenko, et al., New J. Phys. \textbf{8}, 49 (2006)). We find a strong resonant enhancement of the spin relaxation time appears for spin align along [$1\bar{1}0$] at a certain electron density at 4 K. This resonant peak is smeared out with increasing the temperature.Comment: 4 pages, 4 figure

Interplay between s-d exchange interaction and Rashba effect: spin-polarized transport

We investigate the spin-polarized transport properties of a two-dimensional electron gas in a n-type diluted magnetic narrow gap semiconductor quantum well subjected to a perpendicular magnetic and electric field. Interesting beating patterns in the magneto resistance are found which can be tuned significantly by varying the electric field. A resonant enhancement of spin-polarized current is found which is induced by the competition between the s-d exchange interaction and the Rashba effect [Y. A. Bychkov and E. I. Rashba, J. Phys. C 17, 6039 (1984)].Comment: 4 pages, 3 figures, Appl. Phys. Lett. (in press

PENAMBATAN MOLEKUL GLUTATION FAUNA LAUT TERHADAP RESEPTOR DARI BEBERAPA PENYAKIT VIRUS

Glutathion is a tripeptides produced by almost all living creatures, including marine fauna such as rotifers and shrimps. Judging from the important molecular role of glutathion in living cell,  the ability of glutathion as antiviral compound, has been assed by application of the AutodockTools to predict the ability of glutathion as ligand to bind receptors of several viral diseases such as  covid-19, malaria, and hepatitis B. Docking results of glutathion toward target receptor were shown by the parameter, Gibbs energy value, and supported by other data such as the amount of hidrogen bond, amino acid residues, and bond distance. Evidently, the glutathion could bind to  each receptor of covid-19, malaria and hepatitis B, with values of  Gibbs energy (∆G), -7,9, 7,1 and -7,1 kcal/mol, respectively. This proves that glutathion has ability to bind covid-19 receptor, even stronger than its ability to bind receptors of other viral diseases, and to the remdesevir. Between glutathion and covid-19 receptor, there were 11 hidrogen bonds, with distance ranged from 2,76 to 3,25 Å. These were stronger than those between glutathion and receptors of malaria and hepatitis B, only  8 and 4 Å hidrogen bonds, respectively.  To develop glutathion as antiviral drug, it is necessary to carry out in vitro and in vivo analyses, prior to clinical test. Therefore, it requires to explore the marine fauna species that produce glutathion and their cultivation.Keywords: molecular docking, glutathion, marine fauna, autodock vina, viral diseases, binding affinit

Tracing ancestry with methylation patterns: most crypts appear distantly related in normal adult human colon

BACKGROUND: The ability to discern ancestral relationships between individual human colon crypts is limited. Widely separated crypts likely trace their common ancestors to a time around birth, but closely spaced adult crypts may share more recent common ancestors if they frequently divide by fission to form clonal patches. Alternatively, adult crypts may be long-lived structures that infrequently divide or die. METHODS: Methylation patterns (the 5' to 3' order of methylation) at CpG sites that exhibit random changes with aging were measured from isolated crypts by bisulfite genomic sequencing. This epigenetic drift may be used to infer ancestry because recently related crypts should have similar methylation patterns. RESULTS: Methylation patterns were different between widely separated ("unrelated") crypts greater than 15 cm apart. Evidence for a more recent relationship between directly adjacent or branched crypts could not be found because their methylation pattern distances were not significantly different than widely separated crypt pairs. Methylation patterns are essentially equally different between two adult human crypts regardless of their relative locations. CONCLUSIONS: Methylation patterns appear to record somatic cell trees. Starting from a single cell at conception, sequences replicate and may drift apart. Most adult human colon crypts appear to be long-lived structures that become mosaic with respect to methylation during aging

Identifying Selected Regions from Heterozygosity and Divergence Using a Light-Coverage Genomic Dataset from Two Human Populations

When a selective sweep occurs in the chromosomal region around a target gene in two populations that have recently separated, it produces three dramatic genomic consequences: 1) decreased multi-locus heterozygosity in the region; 2) elevated or diminished genetic divergence (FST) of multiple polymorphic variants adjacent to the selected locus between the divergent populations, due to the alternative fixation of alleles; and 3) a consequent regional increase in the variance of FST (S2FST) for the same clustered variants, due to the increased alternative fixation of alleles in the loci surrounding the selection target. In the first part of our study, to search for potential targets of directional selection, we developed and validated a resampling-based computational approach; we then scanned an array of 31 different-sized moving windows of SNP variants (5–65 SNPs) across the human genome in a set of European and African American population samples with 183,997 SNP loci after correcting for the recombination rate variation. The analysis revealed 180 regions of recent selection with very strong evidence in either population or both. In the second part of our study, we compared the newly discovered putative regions to those sites previously postulated in the literature, using methods based on inspecting patterns of linkage disequilibrium, population divergence and other methodologies. The newly found regions were cross-validated with those found in nine other studies that have searched for selection signals. Our study was replicated especially well in those regions confirmed by three or more studies. These validated regions were independently verified, using a combination of different methods and different databases in other studies, and should include fewer false positives. The main strength of our analysis method compared to others is that it does not require dense genotyping and therefore can be used with data from population-based genome SNP scans from smaller studies of humans or other species

Characterizing the Role of Cell-Wall β-1,3-Exoglucanase Xog1p in Candida albicans Adhesion by the Human Antimicrobial Peptide LL-37

Candida albicans is the major fungal pathogen of humans. Its adhesion to host-cell surfaces is the first critical step during mucosal infection. Antimicrobial peptides play important roles in the first line of mucosal immunity against C. albicans infection. LL-37 is the only member of the human cathelicidin antimicrobial peptide family and is commonly expressed in various tissues, including epithelium. We previously showed that LL-37 significantly reduced C. albicans adhesion to plastic, oral epidermoid OECM-1 cells, and urinary bladders of female BALB/c mice. The inhibitory effect of LL-37 on cell adhesion occurred via the binding of LL-37 to cell-wall carbohydrates. Here we showed that formation of LL-37–cell-wall protein complexes potentially inhibits C. albicans adhesion to polystyrene. Using phage display and ELISA, we identified 10 peptide sequences that could bind LL-37. A BLAST search revealed that four sequences in the major C. albicans cell-wall β-1,3-exoglucanase, Xog1p, were highly similar to the consensus sequence derived from the 10 biopanned peptides. One Xog1p-derived peptide, Xog1p90–115, and recombinant Xog1p associated with LL-37, thereby reversing the inhibitory effect of LL-37 on C. albicans adhesion. LL-37 reduced Xog1p activity and thus interrupted cell-wall remodeling. Moreover, deletion of XOG1 or another β-1,3-exoglucanase-encoding gene EXG2 showed that only when XOG1 was deleted did cellular exoglucanase activity, cell adhesion and LL-37 binding decrease. Antibodies against Xog1p also decreased cell adhesion. These data reveal that Xog1p, originally identified from LL-37 binding, has a role in C. albicans adhesion to polystyrene and, by inference, attach to host cells via direct or indirect manners. Compounds that target Xog1p might find use as drugs that prevent C. albicans infection. Additionally, LL-37 could potentially be used to screen for other cell-wall components involved in fungal cell adhesion

Rationale and design of the randomised clinical trial comparing early medication change (EMC) strategy with treatment as usual (TAU) in patients with Major Depressive Disorder - the EMC trial

<p>Abstract</p> <p>Background</p> <p>In Major Depressive Disorder (MDD), the traditional belief of a delayed onset of antidepressants' effects has lead to the concept of current guidelines that treatment durations should be between 3-8 weeks before medication change in case of insufficient outcome. Post hoc analyses of clinical trials, however, have shown that improvement usually occurs within the first 10-14 days of treatment and that such early improvement (Hamilton Depression Rating Scale [HAMD] decrease ≥20%) has a substantial predictive value for final treatment outcome. Even more important, non-improvement (HAMD decrease <20%) after 14 days of treatment was found to be highly predictive for a poor final treatment outcome.</p> <p>Methods/Design</p> <p>The EMC trial is a phase IV, multi-centre, multi-step, randomized, observer-blinded, actively controlled parallel-group clinical trial to investigate for the first time prospectively, whether non-improvers after 14 days of antidepressant treatment with an early medication change (EMC) are more likely to attain remission (HAMD-17 ≤7) on treatment day 56 compared to patients treated according to current guideline recommendation (treatment as usual; TAU). In level 1 of the EMC trial, non-improvers after 14 days of antidepressant treatment will be randomised to an EMC strategy or TAU. The EMC strategy for this study schedules a first medication change on day 15; in case of non-improvement between days 15-28, a second medication change will be performed. TAU schedules the first medication change after 28 days in case of non-response (HAMD-17 decrease <50%). Both interventions will last 42 days. In levels 2 and 3, EMC strategies will be compared with TAU strategies in improvers on day 14, who experience a stagnation of improvement during the course of treatment. The trial is supported by the German Federal Ministry of Education and Research (BMBF) and will be conducted in cooperation with the BMBF funded Interdisciplinary Centre Clinical Trials (IZKS) at the University Medical Centre Mainz and at six clinical trial sites in Germany.</p> <p>Discussion</p> <p>If the EMC strategies lead to significantly more remitters, changes of clinical practice, guidelines for the treatment of MDD as well as research settings can be expected.</p> <p>Trial Registration</p> <p><b>Clincaltrials.gov Identifier</b>: NCT00974155; <b>EudraCT</b>: 2008-008280-96.</p

Optical Properties of GaSb Nanofibers

Amorphous GaSb nanofibers were obtained by ion beam irradiation of bulk GaSb single-crystal wafers, resulting in fibers with diameters of ~20 nm. The Raman spectra and photoluminescence (PL) of the ion irradiation-induced nanofibers before and after annealing were studied. Results show that the Raman intensity of the GaSb LO phonon mode decreased after ion beam irradiation as a result of the formation of the amorphous nanofibers. A new mode is observed at ~155 cm-1 both from the unannealed and annealed GaSb nanofiber samples related to the A1g mode of Sb–Sb bond vibration. Room temperature PL measurements of the annealed nanofibers present a wide feature band at ~1.4–1.6 eV. The room temperature PL properties of the irradiated samples presents a large blue shift compared to bulk GaSb. Annealed nanofibers and annealed nanofibers with Au nanodots present two different PL peaks (400 and 540 nm), both of which may originate from Ga or O vacancies in GaO. The enhanced PL and new band characteristics in nanostructured GaSb suggest that the nanostructured fibers may have unique applications in optoelectronic devices

Leaders, leadership and future primary care clinical research

Background: A strong and self confident primary care workforce can deliver the highest quality care and outcomes equitably and cost effectively. To meet the increasing demands being made of it, primary care needs its own thriving research culture and knowledge base. Methods: Review of recent developments supporting primary care clinical research. Results: Primary care research has benefited from a small group of passionate leaders and significant investment in recent decades in some countries. Emerging from this has been innovation in research design and focus, although less is known of the effect on research output. Conclusion: Primary care research is now well placed to lead a broad re-vitalisation of academic medicine, answering questions of relevance to practitioners, patients, communities and Government. Key areas for future primary care research leaders to focus on include exposing undergraduates early to primary care research, integrating this early exposure with doctoral and postdoctoral research career support, further expanding cross disciplinary approaches, and developing useful measures of output for future primary care research investment

Covariation in Plant Functional Traits and Soil Fertility within Two Species-Rich Forests

The distribution of plant species along environmental gradients is expected to be predictable based on organismal function. Plant functional trait research has shown that trait values generally vary predictably along broad-scale climatic and soil gradients. This work has also demonstrated that at any one point along these gradients there is a large amount of interspecific trait variation. The present research proposes that this variation may be explained by the local-scale sorting of traits along soil fertility and acidity axes. Specifically, we predicted that trait values associated with high resource acquisition and growth rates would be found on soils that are more fertile and less acidic. We tested the expected relationships at the species-level and quadrat-level (20×20 m) using two large forest plots in Panama and China that contain over 450 species combined. Predicted relationships between leaf area and wood density and soil fertility were supported in some instances, but the majority of the predicted relationships were rejected. Alternative resource axes, such as light gradients, therefore likely play a larger role in determining the interspecific variability in plant functional traits in the two forests studied