971 research outputs found
High ambient-contrast-ratio display using tandem reflective liquid crystal display and organic light-emitting device
A high ambient-contrast-ratio (A-CR) and large aperture-ratio display is conceptually demonstrated and experimentally validated by stacking a normally black reflective liquid crystal display (NB-RLCD) and an organic light-emitting device (OLED). Such a tandem device can be switched between the NB-RLCD mode and the OLED mode under bright and dark ambient light, respectively. The normally black characteristic of the RLCD also helps to boost the A-CR under OLED-mode operation. To obtain a better image quality in the RLCD mode, a bumpy and transmissive structure is used to eliminate the specular reflection and to increase the viewing angle performance that results in CR \u3e 2:1 over 55 degrees viewing cone. Besides, such a structure can also increase the external quantum efficiency of the OLED by 49.4%. In our experiments, regardless of the ambient intensity the A-CR is kept higher than 100:1
Superior Mesenteric Artery Syndrome: A Single-institution Experience
Background:Superior mesenteric artery syndrome (SMAS) is a rare disease in adult. SMAS is characterized by acute, or, more commonly, chronic nonspecific symptoms due to duodenal obstruction and severe malnutrition with reduced arterio-mesenteric angle and distance. Surgical treatment may be necessary in most cases with chronic symptoms or when conservative treatment fails in SMAS.Methods:A retrospective chart review was performed on patients who underwent operation for SMAS from January 2008 to August 2020 in Cardinal Tien Hospital. Patients’ clinical presentations, surgical intervention, and outcomes.Results:Data from a total of 14 patients diagnosed with SMAS were analyzed, of which seven were diagnosed with SMAS by abdominal computed tomography and upper gastrointestinal series with water-soluble barium contrast. Six of the confirmed cases underwent surgery, namely, gastric decompression using a nasogastric tube, andcorrection of electrolyte imbalance. The nasoduodenal tube was placed through the obstructed duodenum to provide a high-nutrient fluid supplement. After conservative treatment failure, the patients underwent surgery. Of the six patients, four underwent duodenojejunostomy, one underwent a mini-laparotomy duodenojejunostomy bypass, and the last one underwent Roux-en-Y duodenojejunal bypass with duodenal feeding tube insertion.Conclusion:Patients with SMAS should initially be treated conservative. Surgical intervention should be considered in patients in whom conservative treatments were not effective.Complete resolution of all symptoms may not always be guaranteed after surgical intervention. Laparoscopy is currently widely used. In well-selected patients, minimally invasive or mini-laparotomy duodenojejunostomy is a safe and effective treatment for SMAS. The main advantages of mini-laparotomy duodenojejunostomy over other surgical approaches include half-length surgical incision and a shorter operative time. Duodenojejunostomy is rapidly becoming the standard procedure of this condition, and it has excellent outcomes comparable with those of open surgery
Characterization of porcine circovirus type 2 (PCV2) capsid particle assembly and its application to virus-like particle vaccine development
Porcine circovirus type 2 (PCV2) is the primary
causative agent of porcine circovirus-associated diseases in
pigs. The sole structural capsid protein of PCV2, Cap, consists
of major antigenic domains, but little is known about the
assembly of capsid particles. The purpose of this study is to
produce a large amount of Cap protein using Escherichia coli
expression system for further studying the essential sequences
contributing to formation of particles. By using codon optimization
of rare arginine codons near the 5′-end of the cap
gene for E. coli, a full-length Cap without any fusion tag
recombinant protein (Cap1-233) was expressed and proceeded
to form virus-like particles (VLPs) in normal Cap
appearance that resembled the authentic PCV2 capsid. The
N-terminal deletion mutant (Cap51-233) deleted the nuclear
localization signal (NLS) domain, while the internal deletion
mutant (CapΔ51-103) deleted a likely dimerization domain
that failed to form VLPs. The unique Cys108 substitution
mutant (CapC/S) exhibited most irregular aggregates, and
only few VLPs were formed. These results suggest that the
N-terminal region within the residues 1 to 103 possessing the
NLS and dimerization domains are essential for self-assembly
of stable Cap VLPs, and the unique Cys108 plays an important
role in the integrity of VLPs. The immunogenicity of
PCV2 VLPs was further evaluated by immunization of pigs
followed by challenge infection. The Cap1-233-immunized
pigs demonstrated specific antibody immune responses and are
prevented from PCV2 challenge, thus implying its potential use
for a VLP-based PCV2 vaccine
Synthesis and characterization of new fluorescent two-photon absorption chromophores{
A series of dipolar and quadrupolar type two-photon absorption (TPA) compounds has been synthesized and TPA cross sections (s) were measured by Ti:sapphire femtosecond laser excitation fluorescence (l = 800 nm). Among them, the compound ) can be achieved. One quadrupolar molecule (13) possessing an arylamine donor and a pyridazine acceptor has both a high s value (1442 GM) and s/MW (1.97 GM/g)
Korean Red Ginseng Improves Blood Pressure Stability in Patients with Intradialytic Hypotension
Introduction. Intradialytic hypotension (IDH) is a common complication during hemodialysis which may increase mortality risks. Low dose of Korean red ginseng (KRG) has been reported to increase blood pressure. Whether KRG can improve hemodynamic stability during hemodialysis has not been examined. Methods. The 8-week study consisted of two phases: observation phase and active treatment phase. According to prehemodialysis blood pressure (BP), 38 patients with IDH were divided into group A (BP ≥ 140/90 mmHg, n = 18) and group B (BP < 140/90 mmHg, n = 20). Patients were instructed to chew 3.5 gm KRG slices at each hemodialysis session during the 4-week treatment phase. Blood pressure changes, number of sessions disturbed by symptomatic IDH, plasma levels of vasoconstrictors, blood biochemistry, and adverse effects were recorded. Results. KRG significantly reduced the degree of blood pressure drop during hemodialysis (P < 0.05) and the frequency of symptomatic IDH (P < 0.05). More activation of vasoconstrictors (endothelin-1 and angiotensin II) during hemodialysis was found. The postdialytic levels of endothelin-1 and angiotensin II increased significantly (P < 0.01). Conclusion. Chewing KRG renders IDH patients better resistance to acute BP reduction during hemodialysis via activation of vasoconstrictors. Our results suggest that KRG could be an adjuvant treatment for IDH
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Patients Infected with CRF07_BC Have Significantly Lower Viral Loads than Patients with HIV-1 Subtype B: Mechanism and Impact on Disease Progression
The circulating recombinant form (CRF) 07_BC is the most prevalent HIV-1 strain among injection drug users (IDUs) in Taiwan. It contains a 7 amino-acid deletion in its p6gag. We conducted a cohort study to compare viral loads and CD4 cell count changes between patients infected with subtype B and CRF07_BC and to elucidate its mechanism. Twenty-one patients infected with CRF07_BC and 59 patients with subtype B were selected from a cohort of 667 HIV-1/AIDS patients whom have been followed up for 3 years. Generalized estimated equation was used to analyze their clinical data and the results showed that patients infected with CRF07_BC had significantly lower viral loads (about 58,000 copies per ml less) than patients with subtype B infection (p = 0.002). The replicative capacity of nine CRF07_BC and four subtype B isolates were compared and the results showed that the former had significantly lower replicative capacity than the latter although all of them were CCR5- tropic and non-syncytium inducing viruses. An HIV-1-NL4-3 mutant virus which contains a 7 amino-acid deletion in p6gag (designated as 7d virus) was generated and its live cycle was investigated. The results showed that 7d virus had significantly lower replication capacity, poorer protease-mediated processing and viral proteins production. Electron microscopic examination of cells infected with wild-type or 7d virus demonstrated that the 7d virus had poorer and slower viral maturation processes: more viruses attached to the cell membrane and higher proportion of immature virions outside the cells. The interaction between p6gag and Alix protein was less efficient in cells infected with 7d virus. In conclusion, patients infected with CRF07_BC had significantly lower viral loads than patients infected with subtype B and it may due to the deletion of 7 amino acids which overlaps with Alix protein-binding domain of the p6gag
WDHD1 modulates the post-transcriptional step of the centromeric silencing pathway
The centromere is a highly specialized chromosomal element that is essential for chromosome segregation during mitosis. Centromere integrity must therefore be properly preserved and is strictly dependent upon the establishment and maintenance of surrounding chromatin structure. Here we identify WDHD1, a WD40-domain and HMG-domain containing protein, as a key regulator of centromere function. We show that WDHD1 associates with centromeres in a cell cycle-dependent manner, coinciding with mid-to-late S phase. WDHD1 down-regulation compromises HP1α localization to pericentric heterochromatin and leads to altered expression of epigenetic markers associated with this chromatin region. As a consequence, such reduced epigenetic silencing is manifested in disrupted heterochromatic state of the centromere and a defective mitosis. Moreover, we demonstrate that a possible underlying mechanism of WDHD1’s involvement lies in the proper generation of the small non-coding RNAs encoded by the centromeric satellite repeats. This role is mediated at the post-transcriptional level and likely through stabilizing Dicer association with centromeric RNA. Collectively, these findings suggest that WDHD1 may be a critical component of the RNA-dependent epigenetic control mechanism that sustains centromere integrity and genomic stability
An Empirical Comparison of Consumer Innovation Adoption Models: Implications for Subsistence Marketplaces
So called “pro-poor” innovations may improve consumer wellbeing in subsistence marketplaces. However, there is little research that integrates the area with the vast literature on innovation adoption. Using a questionnaire where respondents were asked to provide their evaluations about a mobile banking innovation, this research fills this gap by providing empirical evidence of the applicability of existing innovation adoption models in subsistence marketplaces. The study was conducted in Bangladesh among a geographically dispersed sample. The data collected allowed an empirical comparison of models in a subsistence context. The research reveals the most useful models in this context to be the Value Based Adoption Model and the Consumer Acceptance of Technology model. In light of these findings and further examination of the model comparison results the research also shows that consumers in subsistence marketplaces are not just motivated by functionality and economic needs. If organizations cannot enhance the hedonic attributes of a pro-poor innovation, and reduce the internal/external constraints related to adoption of that pro-poor innovation, then adoption intention by consumers will be lower
Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an
Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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