552 research outputs found

    Minimum Joint Depth for Moment Frames with High-Strength Materials

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    This paper reports results from four large-scale interior beam column connections without transverse beams or slabs tested under reversed cyclic displacements. The specimens, which included the first of interior beam-column connections constructed with Grade 100 (690) reinforcement with bar deformations similar to those available in U.S. practice, had Grade 60 or 100 (420 or 690) bars, 4 or 10 ksi (28 or 69 MPa) concrete, and varied column depthto-beam bar diameter ratios. The specimens all exhibited strengths greater than the nominal strength, retained at least 80% of their strength to drift ratios exceeding 5%, and exceeded ACI 374 acceptance criteria at a 3% drift ratio for components of special moment frames, demonstrating that well-detailed joints constructed with high-strength materials behave satisfactorily. The data add evidence that joints constructed with high-strength concrete exhibit less bond decay, and recommendations are made for accounting for this effect in design. Results from the specimen constructed with normal-strength materials, considered in the context of prior tests, suggest a need to increase the minimum joint depth for special moment frames. Considerable improvement in behavior associated with reduced bond damage within the joint is obtained from a 20% increase in the minimum column depth-to-beam bar diameter ratio required in ACI 318-19

    The Influence of Dopamine Receptor D4 Polymorphism on Resting EEG in Healthy Young Females

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    The polymorphism of variable number of tandem repeat (VNTR) in dopamine receptor D4 (DRD4) gene exon III has been linked to various neuro-psychiatric conditions with disinhibition/impulsivity as one of the core features. This study examined the modulatory effects of long-allele variant of DRD4 VNTR on the regional neural activity as well as inter-regional neural interactions in a young female population. Blood sample and resting state eyes-closed EEG signals were collected in 233 healthy females, stratified into two groups by polymerase chain reaction: long-allele carriers (>4- repeat) and non-carriers (<=4-repeat/<=4-repeat). The values of mean power of 18 electrodes and mutual information of 38 channel pairs across theta, alpha, and beta frequencies were analyzed. Our connectivity analysis was based on information theory, which combined Morlet wavelet transform and mutual information calculation. Between-group differences of regional power and connectivity strength were quantified by independent t-test, while between-group differences in global trends were examined by non-parametric analyses. We noticed that DRD4 VNTR long-allele was associated with decreased global connectivity strength (from non-parametric analysis), especially over bi-frontal, biparietal and right fronto-parietal and right fronto-temporal connections (from independent t-tests). The between-group differences in regional power were not robust. Our findings fit with the networks of response inhibition, providing evidence bridging DRD4 long-allele and disinhibition/impulsivity in neuropsychiatric disorders. We suggest future DRD4 studies of imaging genetics incorporate connectivity analysis to unveil its impact on cerebral network

    Metabolomic biomarkers of pancreatic cancer: a meta-analysis study

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    Pancreatic cancer (PC) is an aggressive disease with high mortality rates, however, there is no blood test for early detection and diagnosis of this disease. Several research groups have reported on metabolomics based clinical investigations to identify biomarkers of PC, however there is a lack of a centralized metabolite biomarker repository that can be used for meta-analysis and biomarker validation. Furthermore, since the incidence of PC is associated with metabolic syndrome and Type 2 diabetes mellitus (T2DM), there is a need to uncouple these common metabolic dysregulations that may otherwise diminish the clinical utility of metabolomic biosignatures. Here, we attempted to externally replicate proposed metabolite biomarkers of PC reported by several other groups in an independent group of PC subjects. Our study design included a T2DM cohort that was used as a non-cancer control and a separate cohort diagnosed with colorectal cancer (CRC), as a cancer disease control to eliminate possible generic biomarkers of cancer. We used targeted mass spectrometry for quantitation of literature-curated metabolite markers and identified a biomarker panel that discriminates between normal controls (NC) and PC patients with high accuracy. Further evaluation of our model with CRC, however, showed a drop in specificity for the PC biomarker panel. Taken together, our study underscores the need for a more robust study design for cancer biomarker studies so as to maximize the translational value and clinical implementation.This work was supported by ACS IRG-92-152-17 pilot award number AWD4470404 to KU and AKC. The authors would like to acknowledge the Metabolomics Shared Resource in Georgetown University (Washington DC, USA) partially supported by NIH/NCI/CCSG grant P30-CA05100

    Meta-Analysis of in vitro-Differentiated Macrophages Identifies Transcriptomic Signatures That Classify Disease Macrophages in vivo

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    Macrophages are heterogeneous leukocytes regulated in a tissue- and disease-specific context. While in vitro macrophage models have been used to study diseases empirically, a systematic analysis of the transcriptome thereof is lacking. Here, we acquired gene expression data from eight commonly-used in vitro macrophage models to perform a meta-analysis. Specifically, we obtained gene expression data from unstimulated macrophages (M0) and macrophages stimulated with lipopolysaccharides (LPS) for 2-4 h (M-LPSearly), LPS for 24 h (M-LPSlate), LPS and interferon-gamma (M-LPS+IFN gamma), IFN gamma (M-IFN gamma), interleukin-4 (M-IL4), interleukin-10 (M-IL10), and dexamethasone (M-dex). Our meta-analysis identified consistently differentially expressed genes that have been implicated in inflammatory and metabolic processes. In addition, we built macIDR, a robust classifier capable of distinguishing macrophage activation states with high accuracy (>0.95). We classified in vivo macrophages with macIDR to define their tissue- and disease-specific characteristics. We demonstrate that alveolar macrophages display high resemblance to IL10 activation, but show a drop in IFN gamma signature in chronic obstructive pulmonary disease patients. Adipose tissue-derived macrophages were classified as unstimulated macrophages, but acquired LPS-activation features in diabetic-obese patients. Rheumatoid arthritis synovial macrophages exhibit characteristics of IL10- or IFN gamma-stimulation. Altogether, we defined consensus transcriptional profiles for the eight in vitro macrophage activation states, built a classification model, and demonstrated the utility of the latter for in vivo macrophages

    Metal-slotted polymer optical waveguide device

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    Metal-slotted optical waveguides (MSOWs) using an electro-optic polymer material have been experimentally demonstrated. The device consists of a three-layered slab waveguide in that the thin metal (gold) film strips are embedded on top of the lower cladding. The optical mode shapes and effective index of the propagation modes of the proposed waveguide structure were calculated using a simplified effective index method and a simulation tool. The fabrication and the device characteristics of a variable optical attenuator and an optical phase modulator based on MSOWs are discussed.open5

    Multiple Lineages of Human Breast Cancer Stem/Progenitor Cells Identified by Profiling with Stem Cell Markers

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    Heterogeneity of cancer stem/progenitor cells that give rise to different forms of cancer has been well demonstrated for leukemia. However, this fundamental concept has yet to be established for solid tumors including breast cancer. In this communication, we analyzed solid tumor cancer stem cell markers in human breast cancer cell lines and primary specimens using flow cytometry. The stem/progenitor cell properties of different marker expressing-cell populations were further assessed by in vitro soft agar colony formation assay and the ability to form tumors in NOD/SCID mice. We found that the expression of stem cell markers varied greatly among breast cancer cell lines. In MDA-MB-231 cells, PROCR and ESA, instead of the widely used breast cancer stem cell markers CD44+/CD24-/low and ALDH, could be used to highly enrich cancer stem/progenitor cell populations which exhibited the ability to self renew and divide asymmetrically. Furthermore, the PROCR+/ESA+ cells expressed epithelial-mesenchymal transition markers. PROCR could also be used to enrich cells with colony forming ability from MB-361 cells. Moreover, consistent with the marker profiling using cell lines, the expression of stem cell markers differed greatly among primary tumors. There was an association between metastasis status and a high prevalence of certain markers including CD44+/CD24−/low, ESA+, CD133+, CXCR4+ and PROCR+ in primary tumor cells. Taken together, these results suggest that similar to leukemia, several stem/progenitor cell-like subpopulations can exist in breast cancer

    Autonomous indoor wayfinding for individuals with cognitive impairments

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    <p>Abstract</p> <p>Background</p> <p>A challenge to individuals with cognitive impairments in wayfinding is how to remain oriented, recall routines, and travel in unfamiliar areas in a way relying on limited cognitive capacity. While people without disabilities often use maps or written directions as navigation tools or for remaining oriented, this cognitively-impaired population is very sensitive to issues of abstraction (e.g. icons on maps or signage) and presents the designer with a challenge to tailor navigation information specific to each user and context.</p> <p>Methods</p> <p>This paper describes an approach to providing distributed cognition support of travel guidance for persons with cognitive disabilities. A solution is proposed based on passive near-field RFID tags and scanning PDAs. A prototype is built and tested in field experiments with real subjects. The unique strength of the system is the ability to provide unique-to-the-user prompts that are triggered by context. The key to the approach is to spread the context awareness across the system, with the context being flagged by the RFID tags and the appropriate response being evoked by displaying the appropriate path guidance images indexed by the intersection of specific end-user and context ID embedded in RFID tags.</p> <p>Results</p> <p>We found that passive RFIDs generally served as good context for triggering navigation prompts, although individual differences in effectiveness varied. The results of controlled experiments provided more evidence with regard to applicabilities of the proposed autonomous indoor wayfinding method.</p> <p>Conclusions</p> <p>Our findings suggest that the ability to adapt indoor wayfinding devices for appropriate timing of directions and standing orientation will be particularly important.</p

    The evaluation of a Taiwanese training program in smoking cessation and the trainees' adherence to a practice guideline

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    <p>Abstract</p> <p>Background</p> <p>The Taiwanese government began reimbursement for smoking cessation in 2002. Certification from a training program was required for physicians who wanted reimbursement. The program certified 6,009 physicians till 2007. The objective of this study is to evaluate the short- and long term efficacy of the training program.</p> <p>Methods</p> <p>For short term evaluation, all trainees in 2007 were recruited. For long term evaluation, computer randomly selected 2,000 trainees who received training from 2002 to 2006 were recruited. Course satisfaction, knowledge, confidence in providing smoking cessation services and the adherence to a practice guideline were evaluated by questionnaires.</p> <p>Results</p> <p>Trainees reported high satisfaction with the training program. There was significant difference between pre- and post-test scores in knowledge. Confidence in providing services was lower in the long term evaluation compared to short term evaluation. For adherence to a practice guideline, 86% asked the status of smoking, 88% advised the smokers to quit, 76% assessed the smoker's willingness to quit, 59% assisted the smokers to quit, and 60% arranged follow-up visits for smokers. The incentive of reimbursement was the most significant factor affecting confidence and adherence.</p> <p>Conclusions</p> <p>The training program was satisfactory and effective. Adherence to a practice guideline in our study was better than studies without physician training in other countries.</p

    Breast Cancer Cells Induce Cancer-Associated Fibroblasts to Secrete Hepatocyte Growth Factor to Enhance Breast Tumorigenesis

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    It has been well documented that microenvironment consisting of stroma affects breast cancer progression. However, the mechanisms by which cancer cells and fibroblasts, the major cell type in stroma, interact with each other during tumor development remains to be elucidated. Here, we show that the human cancer-associated fibroblasts (CAFs) had higher activity in enhancing breast tumorigenecity compared to the normal tissue-associated fibroblasts (NAFs) isolated from the same patients. The expression level of hepatocyte growth factor (HGF) in these fibroblasts was positively correlated with their ability to enhance breast tumorigenesis in mice. Deprivation of HGF using a neutralizing antibody reduced CAF-mediated colony formation of human breast cancer cells, indicating that CAFs enhanced cancer cell colony formation mainly through HGF secretion. Co-culture with human breast cancer MDA-MB-468 cells in a transwell system enhanced NAFs to secret HGF as well as promote tumorigenecity. The newly gained ability of these “educated” NAFs became irreversible after continuing this process till fourth passage. These results suggested that breast cancer cells could alter the nature of its surrounding fibroblasts to secrete HGF to support its own progression through paracrine signaling

    Characterization of Epstein-Barr Virus miRNAome in Nasopharyngeal Carcinoma by Deep Sequencing

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    Virus-encoded microRNAs (miRNAs) have been shown to regulate a variety of biological processes involved in viral infection and viral-associated pathogenesis. Epstein-Barr virus (EBV) is a herpesvirus implicated in nasopharyngeal carcinoma (NPC) and other human malignancies. EBV-encoded miRNAs were among the first group of viral miRNAs identified. To understand the roles of EBV miRNAs in the pathogenesis of NPC, we utilized deep sequencing technology to characterize the EBV miRNA transcriptome in clinical NPC tissues. We obtained more than 110,000 sequence reads in NPC samples and identified 44 EBV BART miRNAs, including four new mature miRNAs derived from previously identified BART miRNA precursor hairpins. Further analysis revealed extensive sequence variations (isomiRs) of EBV miRNAs, including terminal isomiRs at both the 5′ and 3′ ends and nucleotide variants. Analysis of EBV genomic sequences indicated that the majority of EBV miRNA nucleotide variants resulted from post-transcriptional modifications. Read counts of individual EBV miRNA in NPC tissue spanned from a few reads to approximately 18,000 reads, confirming the wide expression range of EBV miRNAs. Several EBV miRNAs were expressed at levels similar to highly abundant human miRNAs. Sequence analysis revealed that most of the highly abundant EBV miRNAs share their seed sequences (nucleotides 2–7) with human miRNAs, suggesting that seed sequence content may be an important factor underlying the differential accumulation of BART miRNAs. Interestingly, many of these human miRNAs have been found to be dysregulated in human malignancies, including NPC. These observations not only provide a potential linkage between EBV miRNAs and human malignancy but also suggest a highly coordinated mechanism through which EBV miRNAs may mimic or compete with human miRNAs to affect cellular functions
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