259 research outputs found
Linear Size Optimal q-ary Constant-Weight Codes and Constant-Composition Codes
An optimal constant-composition or constant-weight code of weight has
linear size if and only if its distance is at least . When , the determination of the exact size of such a constant-composition or
constant-weight code is trivial, but the case of has been solved
previously only for binary and ternary constant-composition and constant-weight
codes, and for some sporadic instances.
This paper provides a construction for quasicyclic optimal
constant-composition and constant-weight codes of weight and distance
based on a new generalization of difference triangle sets. As a result,
the sizes of optimal constant-composition codes and optimal constant-weight
codes of weight and distance are determined for all such codes of
sufficiently large lengths. This solves an open problem of Etzion.
The sizes of optimal constant-composition codes of weight and distance
are also determined for all , except in two cases.Comment: 12 page
Micro-layered-photolithography for Micro-Fabrication and Micro-Molding
A novel process based on the principle of layered photolithography has been proposed and tested for making real three-dimensional micro-structures. An experimental setup was designed and built for doing experiments on this micro-fabrication process. An ultraviolet (UV) excimer laser at the wavelength of 248 nm was used as the light source and a single piece of photo-mask carrying a series of two dimensional (2D) patterns sliced from a three dimensional (3D) micro-part was employed for the photolithography process. The experiments were conducted on the solidification of liquid photopolymer from single layer to multiple layers. The single-layer photolithography experiments showed that certain photopolymers could be applied for the 3D micro-fabrication, and solid layers with sharp shapes could be formed from the liquid polymer identified. By using a unique alignment technique, multiple layers of photolithography was successfully realized for a micro-gear with features at 60 microns. Electroforming was also conducted for converting the photopolymer master to a metal cavity of the micro-gear, which proved that the process is feasible for micro-molding.Singapore-MIT Alliance (SMA
Outpatient-Based Therapy of Oral Fludarabine and Subcutaneous Alemtuzumab for Asian Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia
Background. Intravenous alemtuzumab and fludarabine are effective in combination for the treatment of chronic lymphocytic leukemia (CLL), but require hospital visits for intravenous injection. We performed a pilot study to assess the safety and efficacy of outpatient-based oral fludarabine with subcutaneous alemtuzumab (OFSA) for the treatment of relapsed/refractory CLL. Results. Depending on their response, patients were given two to six 28-day cycles of subcutaneous alemtuzumab 30 mg on days 1,3, and 5 and oral fludarabine 40 mg/m2/day for 5 days. Median patient age was 74. The lymphocyte counts of all five patients fell after the 1st cycle of treatment and reached normal/low levels on completion of 2 to 6 cycles of therapy. Platelet counts and hemoglobin were unaffected. All five patients achieved complete hematological remission, while two attained minimal residual disease negativity on 4-color flow cytometry. Conclusions. Our OFSA regimen was effective in elderly Asian patients with relapsed/refractory CLL, and it should be investigated further
Controlled assembly of SNAP-PNA-fluorophore systems on DNA templates to produce fluorescence resonance energy transfer
The SNAP protein is a widely used self-labeling tag that can be used for tracking protein localization and trafficking in living systems. A model system providing controlled alignment of SNAP-tag units can provide a new way to study clustering of fusion proteins. In this work, fluorescent SNAP-PNA conjugates were controllably assembled on DNA frameworks forming dimers, trimers, and tetramers. Modification of peptide nucleic acid (PNA) with the O6-benzyl guanine (BG) group allowed the generation of site-selective covalent links between PNA and the SNAP protein. The modified BG-PNAs were labeled with fluorescent Atto dyes and subsequently chemo-selectively conjugated to SNAP protein. Efficient assembly into dimer and oligomer forms was verified via size exclusion chromatography (SEC), electrophoresis (SDS-PAGE), and fluorescence spectroscopy. DNA directed assembly of homo- and hetero-dimers of SNAP-PNA constructs induced homo- and hetero-FRET, respectively. Longer DNA scaffolds controllably aligned similar fluorescent SNAP-PNA constructs into higher oligomers exhibiting homo-FRET. The combined SEC and homo-FRET studies indicated the 1:1 and saturated assemblies of SNAP-PNA-fluorophore:DNA formed preferentially in this system. This suggested a kinetic/stoichiometric model of assembly rather than binomially distributed products. These BG-PNA-fluorophore building blocks allow facile introduction of fluorophores and/or assembly directing moieties onto any protein containing SNAP. Template directed assembly of PNA modified SNAP proteins may be used to investigate clustering behavior both with and without fluorescent labels which may find use in the study of assembly processes in cells
Integrated Transcriptomics, Metabolomics, and Lipidomics Profiling in Rat Lung, Blood, and Serum for Assessment of Laser Printer-Emitted Nanoparticle Inhalation Exposure-Induced Disease Risks
settings Open AccessArticle Integrated Transcriptomics, Metabolomics, and Lipidomics Profiling in Rat Lung, Blood, and Serum for Assessment of Laser Printer-Emitted Nanoparticle Inhalation Exposure-Induced Disease Risks by Nancy Lan Guo 1,*,Tuang Yeow Poh 2,Sandra Pirela 3,Mariana T. Farcas 4,Sanjay H. Chotirmall 2,Wai Kin Tham 5,Sunil S. Adav 5,Qing Ye 1,Yongyue Wei 6,Sipeng Shen 2,David C. Christiani 2,Kee Woei Ng 3,7,8,Treye Thomas 9,Yong Qian 4 andPhilip Demokritou 3 1 West Virginia University Cancer Institute/School of Public Health, West Virginia University, Morgantown, WV 26506, USA 2 Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore 3 Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T. H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA 4 Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA 5 Singapore Phenome Centre, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore 6 Key Lab for Modern Toxicology, Department of Epidemiology and Biostatistics and Ministry of Education (MOE), School of Public Health, Nanjing Medical University, Nanjing 210029, China 7 School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore 8 Environmental Chemistry and Materials Centre, Nanyang Environment & Water Research Institute, Singapore 637141, Singapore 9 Office of Hazard Identification and Reduction, U.S. Consumer Product Safety Commission, Rockville, MD 20814, USA * Author to whom correspondence should be addressed. Int. J. Mol. Sci. 2019, 20(24), 6348; https://doi.org/10.3390/ijms20246348 Received: 2 December 2019 / Revised: 12 December 2019 / Accepted: 13 December 2019 / Published: 16 December 2019 (This article belongs to the Special Issue Advances in Nanostructured Materials between Pharmaceutics and Biomedicine) Download PDF Browse Figures Review Reports Cite This Paper Abstract Laser printer-emitted nanoparticles (PEPs) generated from toners during printing represent one of the most common types of life cycle released particulate matter from nano-enabled products. Toxicological assessment of PEPs is therefore important for occupational and consumer health protection. Our group recently reported exposure to PEPs induces adverse cardiovascular responses including hypertension and arrythmia via monitoring left ventricular pressure and electrocardiogram in rats. This study employed genome-wide mRNA and miRNA profiling in rat lung and blood integrated with metabolomics and lipidomics profiling in rat serum to identify biomarkers for assessing PEPs-induced disease risks. Whole-body inhalation of PEPs perturbed transcriptional activities associated with cardiovascular dysfunction, metabolic syndrome, and neural disorders at every observed time point in both rat lung and blood during the 21 days of exposure. Furthermore, the systematic analysis revealed PEPs-induced transcriptomic changes linking to other disease risks in rats, including diabetes, congenital defects, auto-recessive disorders, physical deformation, and carcinogenesis. The results were also confirmed with global metabolomics profiling in rat serum. Among the validated metabolites and lipids, linoleic acid, arachidonic acid, docosahexanoic acid, and histidine showed significant variation in PEPs-exposed rat serum. Overall, the identified PEPs-induced dysregulated genes, molecular pathways and functions, and miRNA-mediated transcriptional activities provide important insights into the disease mechanisms. The discovered important mRNAs, miRNAs, lipids and metabolites may serve as candidate biomarkers for future occupational and medical surveillance studies. To the best of our knowledge, this is the first study systematically integrating in vivo, transcriptomics, metabolomics, and lipidomics to assess PEPs inhalation exposure-induced disease risks using a rat model
Cortical microinfarcts in memory clinic patients are associated with reduced cerebral perfusion
Cerebral cortical microinfarcts (CMIs) are small ischemic lesions associated with cognitive impairment and dementia.
CMIs are frequently observed in cortical watershed areas suggesting that hypoperfusion contributes to their development. We investigated if presence of CMIs was related to a decrease in cerebral perfusion, globally or specifically in
cortex surrounding CMIs. In 181 memory clinic patients (mean age 72 9 years, 51% male), CMI presence was rated on
3-T magnetic resonance imaging (MRI). Cerebral perfusion was assessed from cortical gray matter of the anterior
circulation using pseudo-continuous arterial spin labeling parameters cerebral blood flow (CBF) (perfusion in mL blood/
100 g tissue/min) and spatial coefficient of variation (CoV) (reflecting arterial transit time (ATT)). Patients with CMIs had a
12% lower CBF (beta ¼ .20) and 22% higher spatial CoV (beta ¼ .20) (both p <.05) without a specific regional pattern
on voxel-based CBF analysis. CBF in a 2 cm region-of-interest around the CMIs did not differ from CBF in a reference
zone in the contralateral hemisphere. These findings show that CMIs in memory clinic patients are primarily related to
global reductions in cerebral perfusion, thus she
Consumer Adoption of Self-Service Technologies in the Context of the Jordanian Banking Industry: Examining the Moderating Role of Channel Types
YesThis study aimed to examine the key factors predicting Jordanian consumers’ intentions and
usage of three types of self-service banking technologies. This study also sought to test if the
impacts of these main predictors could be moderated by channel type. This study proposed a
conceptual model by integrating factors from the unified theory of acceptance and use of
technology (UTAUT), along with perceived risk. The required data were collected from a
convenience sample of Jordanian banking customers using a survey questionnaire. The
statistical results strongly support the significant influence of performance expectancy, social
influence, and perceived risk on customer intentions for the three types of SSTs examined. The
results of the X2 differences test also indicate that there are significant differences in the
influence of the main predictors due to the moderating effect of channel type. One of the key
contributions of this study is that three types of SSTs were tested in a single study, which had
not been done before, leading to the identification of the factors common to all three types, as
well as the salient factors unique to each type
Factors associated with nursing home placement of all patients admitted for inpatient rehabilitation in Singapore community hospitals from 1996 to 2005: A disease stratified analysis
10.1371/journal.pone.0082697PLoS ONE812-POLN
Cortical microinfarcts in memory clinic patients are associated with reduced cerebral perfusion
Cerebral cortical microinfarcts (CMIs) are small ischemic lesions associated with cognitive impairment and dementia. CMIs are frequently observed in cortical watershed areas suggesting that hypoperfusion contributes to their development. We investigated if presence of CMIs was related to a decrease in cerebral perfusion, globally or specifically in cortex surrounding CMIs. In 181 memory clinic patients (mean age 72 ± 9 years, 51% male), CMI presence was rated on 3-T magnetic resonance imaging (MRI). Cerebral perfusion was assessed from cortical gray matter of the anterior circulation using pseudo-continuous arterial spin labeling parameters cerebral blood flow (CBF) (perfusion in mL blood/100 g tissue/min) and spatial coefficient of variation (CoV) (reflecting arterial transit time (ATT)). Patients with CMIs had a 12% lower CBF (beta = −.20) and 22% higher spatial CoV (beta =.20) (both p <.05) without a specific regional pattern on voxel-based CBF analysis. CBF in a 2 cm region-of-interest around the CMIs did not differ from CBF in a reference zone in the contralateral hemisphere. These findings show that CMIs in memory clinic patients are primarily related to global reductions in cerebral perfusion, thus shedding new light on the etiology of vascular brain injury in dementia
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