56 research outputs found
Skin barrier dysfunction in common genetic disorders
One of the most important roles of the skin is the formation of an effective barrier to prevent desiccation as well as to keep out foreign pathogens and allergens. This is a tightly regulated process and involves many structural proteins, lipids, enzymes and biochemical components. One of the proteins that has an indispensable role in barrier formation is filaggrin, which is encoded by the filaggrin gene (FLG) that lies within a cluster of epidermal genes known as the epidermal differentiation complex (EDC) on chromosome 1q21. Recent studies in Europe have shown that null mutations in FLG lead to the loss of the filaggrin protein; this is the underlying genetic cause of ichthyosis vulgaris (IV) and is a significant predisposing factor for atopic dermatitis (AD) and other atopic conditions such as asthma, allergic rhinitis and food allergy. In this thesis, the critical role of FLG-null mutations was examined and confirmed as a strong predisposing factor for AD in Singaporean Chinese patients. In addition, AD patients with FLG mutations also showed an increased susceptibility for recurrent skin infections. Interestingly, a diverse and wide spectrum of FLG-null mutations was identified in the Singaporean Chinese population, as opposed to the dominance of a few common FLG mutations in Europe. This result highlighted discrete genetic variations between different ethnic groups. FLG-null mutations were also shown to have significant gene modifying effects on other skin barrier genes such as steroid sulphatase gene (STS) to exacerbate the phenotype of X-linked ichthyosis (XLI). Next, the effect of FLGĀ¬-null mutations on other complex conditions such as acne vulgaris and childhood peanut sensitisation was investigated but no significant association of FLG mutations with these diseases were observed in the Singaporean Chinese population. Lastly, a study was attempted to search for a candidate gene for psoriasis within the EDC, through the use of fine mapping techniques. With the advent of faster and cheaper next generation sequencing (NGS) in the near future, the quest for susceptibility factors in complex traits will increase in effectiveness and speed.EThOS - Electronic Theses Online ServiceAgency for Science, Technology and Research (A*STAR) Graduate Academy, SingaporeGBUnited Kingdo
Oblivious Parallel RAM: Improved Efficiency and Generic Constructions
Oblivious RAM (ORAM) garbles read/write operations by a client (to
access a remote storage server or a random-access memory) so that an
adversary observing the garbled access sequence cannot infer any
information about the original operations, other than their overall
number. This paper considers the natural setting of Oblivious
Parallel RAM (OPRAM) recently introduced by Boyle, Chung, and
Pass (TCC 2016A), where clients simultaneously access in
parallel the storage server. The clients are additionally
connected via point-to-point links to coordinate their
accesses. However, this additional inter-client communication must
also remain oblivious.
The main contribution of this paper is twofold: We construct the
first OPRAM scheme that (nearly) matches the storage and
server-client communication complexities of the most efficient
single-client ORAM schemes. Our scheme is based on an extension of
Path-ORAM by Stefanov et al (CCS 2013). Moreover, we present a
generic transformation turning any (single-client) ORAM scheme
into an OPRAM scheme
Expression of an IRF-3 fusion protein and mouse estrogen receptor, inhibits hepatitis C viral replication in RIG-I-deficient Huh 7.5 cells
Interferon Regulatory Factor-3 (IRF-3) plays a central role in the induction of interferon (IFN) production and succeeding interferon-stimulated genes (ISG) expression en route for restraining hepatitis C virus (HCV) infection. Here, we established a stable Huh7.5-IRF3ER cell line expressing a fusion protein of IRF-3 and mouse estrogen receptor (ER) to examine IFN production and anti-HCV effects of IRF-3 in retinoic acid inducible-gene-I (RIG-I) deficient Huh 7.5 cells. Homodimerization of the IRF-3ER fusion protein was detected by Western blotting after treatment with the estrogen receptor agonist 4-hydrotamoxifen (4-HT) in Huh7.5-IRF3ER cells. Expression of IFN-Ī±, IFN-Ī², and their inhibitory effects on HCV replication were demonstrated by real-time polymerase chain reaction (PCR). Peak expression of IFN-Ī± and IFN-Ī² was achieved 24-hours post 4-HT treatment, coinciding with the appearance of phosphorylated signal transducer and activator of transcription (STAT) proteins. Additionally, HCV viral replication declined in time-dependent fashion. In previous studies, a novel IFN-mediated pathway regulating expression of 1-8U and heterogeneous nuclear ribonucleoprotein M (hnRNP M) inhibited HCV internal ribosomal entry site (IRES)-dependent translation. When expression of ISGs such as 1-8U and hnRNP M were measured in 4-HT-treated Huh7.5-IRF3ER cells, both genes were positively regulated by activation of the IRF-3ER fusion protein. In conclusion, the anti-HCV effects of IRF-3ER homodimerization inhibited HCV RNA replication as well as HCV IRES-dependent translation in Huh7.5-IRF3ER cells. The results of this study indicate that IRF-3ER homodimerization is a key step to restore IFN expression in Huh7.5-IRF3ER cells and in achieving its anti-HCV effects
DiffUTE: Universal Text Editing Diffusion Model
Diffusion model based language-guided image editing has achieved great
success recently. However, existing state-of-the-art diffusion models struggle
with rendering correct text and text style during generation. To tackle this
problem, we propose a universal self-supervised text editing diffusion model
(DiffUTE), which aims to replace or modify words in the source image with
another one while maintaining its realistic appearance. Specifically, we build
our model on a diffusion model and carefully modify the network structure to
enable the model for drawing multilingual characters with the help of glyph and
position information. Moreover, we design a self-supervised learning framework
to leverage large amounts of web data to improve the representation ability of
the model. Experimental results show that our method achieves an impressive
performance and enables controllable editing on in-the-wild images with high
fidelity. Our code will be avaliable in
\url{https://github.com/chenhaoxing/DiffUTE}
Y2O3 nanosheets as slurry abrasives for chemical-mechanical planarization of copper
Abstract
Continued reduction in feature dimension in integrated circuits demands high degree of flatness after chemical mechanical polishing. Here we report using new yttrium oxide (Y2O3) nanosheets as slurry abrasives for chemical-mechanical planarization (CMP) of copper. Results showed that the global planarization was improved by 30% using a slurry containing Y2O3 nanosheets in comparison with a standard industrial slurry. During CMP, the two-dimensional square shaped Y2O3 nanosheet is believed to induce the low friction, the better rheological performance, and the laminar flow leading to the decrease in the within-wafer-non-uniformity, surface roughness, as well as dishing. The application of the two-dimensional nanosheets as abrasive in CMP would increase the manufacturing yield of integrated circuits.</jats:p
Gut microbiota alterations are associated with functional outcomes in patients of acute ischemic stroke with non-alcoholic fatty liver disease
IntroductionPatients with acute ischemic stroke (AIS) with non-alcoholic fatty liver disease (NAFLD) frequently have poor prognosis. Many evidences suggested that the changes in gut microbiota may play an important role in the occurrence and development of AIS patients with NAFLD. The purpose of this study was to explore microbial characteristics in patients of AIS with NAFLD, and the correlation between gut microbiota and functional outcomes.MethodsThe patients of AIS were recruited and divided into NAFLD group and non-NAFLD group. The stool samples and clinical information were collected. 16ās rRNA sequencing was used to analyze the characteristics of gut microbiota. The patients of AIS with NAFLD were followed-up to evaluate the functional outcomes of disease. The adverse outcomes were determined by modified Rankin scale (mRS) scores at 3āmonths after stroke. The diagnostic performance of microbial marker in predicting adverse outcomes was assessed by recipient operating characteristic (ROC) curves.ResultsOur results showed that the composition of gut microbiota between non-NAFLD group and NAFLD group were different. The characteristic bacteria in the patients of AIS with NAFLD was that the relative abundance of Dorea, Dialister, Intestinibacter and Flavonifractor were decreased, while the relative abundance of Enorma was increased. Moreover, the characteristic microbiota was correlated with many clinical parameters, such as mRS scores, mean arterial pressure and fasting blood glucose level. In addition, ROC models based on the characteristic microbiota or the combination of characteristic microbiota with independent risk factors could distinguish functional dependence patients and functional independence patients in AIS with NAFLD (area under curve is 0.765 and 0.882 respectively).ConclusionThese findings revealed the microbial characteristics in patients of AIS with NAFLD, and further demonstrated the predictive capability of characteristic microbiota for adverse outcomes in patients of AIS with NAFLD
Cortisol dysregulation in anxiety infertile women and the influence on IVF treatment outcome
IntroductionDysregulation of the stress-regulatory hormone cortisol is associated with anxiety, but its potential impact on infertile women and in vitro fertilization (IVF) treatment remains unclear. This prospective cross-sectional study aimed at evaluating the dysregulation of cortisol and its correlation to anxiety in infertile women. The influence of stress on IVF outcomes was also investigated.MethodsA point-of-care test was used for the measurement of morning serum cortisol in 110 infertile women and 112 age-matching healthy individuals. A Self-Rating Anxiety Scale (SAS) was used for the anxiety assessment of infertile women, and 109 of them underwent IVF treatment starting with the GnRH-antagonist protocol. If clinical pregnancy was not achieved, more IVF cycles were conducted with adjusted protocols until the patients got pregnant or gave up.ResultsHigher morning serum cortisol level was identified for infertile patients, especially for the elder. Women with no anxiety showed significant differences in cortisol levels, monthly income, and BMI compared with those with severe anxiety. A strong correlation was found between the morning cortisol level and the SAS score. When the cutoff value is 22.25 Ī¼g/dL, cortisol concentration could predict the onset of anxiety with high accuracy (95.45%) among infertile women. After IVF treatments, women with high SAS scores (>50) or cortisol levels (>22.25 Ī¼g/dL) demonstrated a lower rate of pregnancy (8.0%-10.3%) and more IVF cycles, although the impact of anxiety was not affirmative.ConclusionHypersecretion of cortisol related to anxiety was prevalent among infertile women, but the influence of anxiety on multi-cycle IVF treatment was not affirmative due to the complicated treatment procedures. This study suggested that the assessment of psychological disorders and stress hormone dysregulation should not be overlooked. An anxiety questionnaire and rapid cortisol test might be included in the treatment protocol to provide better medical care
Array-based sequencing of filaggrin gene for comprehensive detection of disease-associated variants
The filaggrin gene (FLG) is essential for skin differentiation and epidermal barrier formation. FLG loss-of-function (LoF) variants are associated with ichthyosis vulgaris and the major genetic risk factor for developing atopic dermatitis (AD).1, 2, 3 Genetic stratification of patients with AD according to FLG LoF risk is a common practice for both research and clinical studies; however, few studies comprehensively sequence the entire FLG coding region. Most studies that include FLG genotyping have screened for common predominant LoF variants to report allele frequencies after full Sanger sequencing of a smaller batch of test patient samples or previously published data. This strategy potentially results in underreporting of the genetic contribution especially in ethnicities where FLG LoF variants are highly diverse.4 Distinct LoF variants have been reported for most ethnicities studied to date. For example, 2 predominant sequence variants (p.R501X and c.2282del4) make up approximately 80% of the mutation burden in northern Europeans,5 whereas in East Asian ethnicities, a larger FLG LoF mutation spectrum is found with fewer predominating variants.6, 7 However, routinely Sanger sequencing the entire FLG coding region for large cohorts is not always feasible, although desirable as it is essential to correctly stratify patients. To address this, we developed a robust and cost-effective high-throughput PCR-based method for analyzing the entire coding region of FLG using Fluidigm microfluidics technology and next-generation sequencing (NGS). We have applied this method to fully resequence cohorts of Chinese, Malay, and Indian patients with AD from the Singaporean population.ASTAR (Agency for Sci., Tech. and Research, Sāpore)Published versio
The Diagnostic Value of Gut Microbiota Analysis for Post-Stroke Sleep Disorders
Background: Gut microbiota have been associated with many psychiatric disorders. However, the changes in the composition of gut microbiota in patients with post-stroke sleep disorders (PSSDs) remain unclear. Here, we determined the gut microbial signature of PSSD patients. Methods: Fecal samples of 205 patients with ischemic stroke were collected within 24 h of admission and were further analyzed using 16 s RNA gene sequencing followed by bioinformatic analysis. The diversity, community composition, and differential microbes of gut microbiota were assessed. The outcome of sleep disorders was determined by the Pittsburgh Sleep Quality Index (PSQI) at 3 months after admission. The diagnostic performance of microbial characteristics in predicting PSSDs was assessed by receiver operating characteristic (ROC) curves. Results: Our results showed that the composition and structure of microbiota in patients with PSSDs were different from those without sleep disorders (PSNSDs). Moreover, the linear discriminant analysis effect size (LEfSe) showed significant differences in gut-associated bacteria, such as species of Streptococcus, Granulicatella, Dielma, Blautia, Paeniclostridium, and Sutterella. We further managed to identify the optimal microbiota signature and revealed that the predictive model with eight operational-taxonomic-unit-based biomarkers achieved a high accuracy in PSSD prediction (AUC = 0.768). Blautia and Streptococcus were considered to be the key microbiome signatures for patients with PSSD. Conclusions: These findings indicated that a specific gut microbial signature was an important predictor of PSSDs, which highlighted the potential of microbiota as a promising biomarker for detecting PSSD patients
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