181 research outputs found
Mediating Color Filter Exploration with Color Theme Semantics Derived from Social Curation Data
A holistic review on fatigue properties of additively manufactured metals
Additive manufacturing (AM) technology is undergoing rapid development and
emerging as an advanced technique that can fabricate complex near-net shaped
and light-weight metallic parts with acceptable strength and fatigue
performance. A number of studies have indicated that the strength or other
mechanical properties of AM metals are comparable or even superior to that of
conventionally manufactured metals, but the fatigue performance is still a
thorny problem that may hinder the replacement of currently used metallic
components by AM counterparts when the cyclic loading and thus fatigue failure
dominates. This article reviews the state-of-art published data on the fatigue
properties of AM metals, principally including -- data and fatigue crack
growth data. The AM techniques utilized to generate samples in this review
include powder bed fusion (e.g., EBM, SLM, DMLS) and directed energy deposition
(e.g., LENS, WAAM). Further, the fatigue properties of AM metallic materials
that involve titanium alloys, aluminum alloys, stainless steel, nickel-based
alloys, magnesium alloys, and high entropy alloys, are systematically
overviewed. In addition, summary figures or tables for the published data on
fatigue properties are presented for the above metals, the AM techniques, and
the influencing factors (manufacturing parameters, e.g., built orientation,
processing parameter, and post-processing). The effects of build direction,
particle, geometry, manufacturing parameters, post-processing, and
heat-treatment on fatigue properties, when available, are provided and
discussed. The fatigue performance and main factors affecting the fatigue
behavior of AM metals are finally compared and critically analyzed, thus
potentially providing valuable guidance for improving the fatigue performance
of AM metals.Comment: 201 pages, 154 figure
Entrepreneurial founder's social ties, institutions, and firm's productivity: Evidences from China's newly listed firms
Social ties, as informal institutions, contribute to firms' performance in emerging economies. Formal market-supporting institutions in emerging economies are in general less developed, social ties cultivated by entrepreneurs thus serve as substitutes for formal institutional support. However, the role of social ties as informal institutions and interactions between social ties and market-supporting institutions are yet to be fully explored. Using the sample of 428 newly listed firms on the Growth Enterprise Market of Shenzhen Stock Exchange of China between 2009 and 2016, this paper examines the interplays among the entrepreneurial founder's political ties and managerial ties, marketization, and firm's productivity, measured by firm-level total factor productivity. Our findings indicate that the entrepreneurial founder's managerial ties enhance firm productivity whilst political ties reduce productivity. We also find that marketization positively moderates the effects of the entrepreneurial founder's political and managerial ties on productivity. Our findings demonstrate the strategic importance of the informal institutions and contribute to an improved understanding of the complementary effects between social ties and marketization in an important emerging economy
Non-Coding Transcriptome Provides Novel Insights into the Escherichia coli F17 Susceptibility of Sheep Lamb
SIMPLE SUMMARY: Diarrhea and vomiting caused by Escherichia coli (E. coli) F17 are considered significant threats to animal farming. In the present study, RNA-Seq was performed to investigate the potential circRNA and miRNA biomarkers for E. coli F17-antagonism (AN) and -sensitive (SE) lambs. The results indicated that circRNA and miRNA expression is closely associated with the susceptibility of E. coli F17 in lambs. Numbers of circRNAs and miRNAs may serve as potential biomarkers for intestinal inflammatory response against E. coli F17 infection. Our study can provide a preliminary understanding of the underlying mechanisms of intestinal immunity. ABSTRACT: It has long been recognized that enterotoxigenic Escherichia coli (ETEC) is the major pathogen responsible for vomiting and diarrhea. E. coli F17, a main subtype of ETEC, is characterized by high morbidity and mortality in young livestock. However, the transcriptomic basis underlying E. coli F17 infection has not been fully understood. In this study, RNA sequencing was performed to explore the expression profiles of circRNAs and miRNAs in the jejunum of E. coli F17-antagonism (AN) and -sensitive (SE) lambs. A total of 16,534 circRNAs and 271 miRNAs (125 novel miRNAs and 146 annotated miRNAs) were screened, and 214 differentially expressed (DE) circRNAs and 53 DE miRNAs were detected between the AN and SE lambs (i.e., novel_circ_0025840, novel_circ_0022779, novel_miR_107, miR-10b). Functional enrichment analyses showed that source genes of DE circRNAs were mainly involved in metabolic-related pathways, while target genes of DE miRNAs were mainly enriched in the immune response pathways. Then, a two-step machine learning approach combining Random Forest (RF) and XGBoost (candidates were first selected by RF and further assessed by XGBoost) was performed, which identified 44 circRNAs and 39 miRNAs as potential biomarkers (i.e., novel_circ_0000180, novel_circ_0000365, novel_miR_192, oar-miR-496-3p) for E. coli infection. Furthermore, circRNA-related and lncRNA-related ceRNA networks were constructed, containing 46 circRNA-miRNA-mRNA competing triplets and 630 lncRNA-miRNA-mRNA competing triplets, respectively. By conducting a serious of bioinformatic analyses, our results revealed important circRNAs and miRNAs that could be potentially developed as candidate biomarkers for intestinal inflammatory response against E. coli F17 infection; our study can provide novel insights into the underlying mechanisms of intestinal immunity
circARL15 Plays a Critical Role in Intervertebral Disc Degeneration by Modulating miR-431-5p/DISC1
BackgroundIntervertebral disk degeneration (IDD) is a serious public health problem associated with genetic and environmental factors. However, the pathogenic factors involved and the pathological mechanism of this disease still remain enigmatic.MethodsThe associated microarray was downloaded and further analyzed using statistical software R. The competing endogenous RNA (ceRNA) co-expression network was constructed to measure the meaningful correlated expression of differentially expressed genes. We further measured the expression of circARL15/miR-431-5p/DISC1 in IDD tissues. Cell proliferation and apoptosis were detected in NP cells transfected with a circARL15 overexpression plasmid and miR-431-5p mimics. The expression of DISC1 was detected by immunohistochemistry and Western blot analysis.ResultsWithin the ceRNA network, circARL15 is the most differentially expressed circular RNA. circARL15 was down-regulated in IDD and was negatively correlated with miR-431-5p and positively associated with DISC1. miR-431-5p was found to bind directly to circARL15 and DISC1. circARL15 inhibited nucleus pulposus cell apoptosis but promoted nucleus pulposus cell proliferation by targeting the miR-431-5p/DISC1 signaling pathway.ConclusioncircARL15/miR-431-5p/DISC1 is involved in the pathogenesis of IDD, which might be helpful in determining the diagnostic biomarkers and providing potential therapeutic targets for patients with IDD
Added value of contrast echocardiography for the evaluation of multiple giant coronary artery aneurysms with coronary to pulmonary arterial fistulas
Model-enhanced Vector Index
Embedding-based retrieval methods construct vector indices to search for
document representations that are most similar to the query representations.
They are widely used in document retrieval due to low latency and decent recall
performance. Recent research indicates that deep retrieval solutions offer
better model quality, but are hindered by unacceptable serving latency and the
inability to support document updates. In this paper, we aim to enhance the
vector index with end-to-end deep generative models, leveraging the
differentiable advantages of deep retrieval models while maintaining desirable
serving efficiency. We propose Model-enhanced Vector Index (MEVI), a
differentiable model-enhanced index empowered by a twin-tower representation
model. MEVI leverages a Residual Quantization (RQ) codebook to bridge the
sequence-to-sequence deep retrieval and embedding-based models. To
substantially reduce the inference time, instead of decoding the unique
document ids in long sequential steps, we first generate some semantic virtual
cluster ids of candidate documents in a small number of steps, and then
leverage the well-adapted embedding vectors to further perform a fine-grained
search for the relevant documents in the candidate virtual clusters. We
empirically show that our model achieves better performance on the commonly
used academic benchmarks MSMARCO Passage and Natural Questions, with comparable
serving latency to dense retrieval solutions
Biventricular longitudinal strain as a predictor of functional improvement after D-shant device implantation in patients with heart failure
BackgroundThe creation of an atrial shunt is a novel approach for the management of heart failure (HF), and there is a need for advanced methods for detection of cardiac function response to an interatrial shunt device. Ventricular longitudinal strain is a more sensitive marker of cardiac function than conventional echocardiographic parameters, but data on the value of longitudinal strain as a predictor of improvement in cardiac function after implantation of an interatrial shunt device are scarce. We aimed to investigate the exploratory efficacy of the D-Shant device for interatrial shunting in treating heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF), and to explore the predictive value of biventricular longitudinal strain for functional improvement in such patients.MethodsA total of 34 patients were enrolled (25 with HFrEF and 9 with HFpEF). All patients underwent conventional echocardiography and two-dimensional speckle tracking echocardiogram (2D-STE) at baseline and 6 months after implantation of a D-Shant device (WeiKe Medical Inc., WuHan, CN). Left ventricular global longitudinal strain (LVGLS) and right ventricular free wall longitudinal strain (RVFWLS) were evaluated by 2D-STE.ResultsThe D-Shant device was successfully implanted in all cases without periprocedural mortality. At 6-month follow-up, an improvement in New York Heart Association (NYHA) functional class was observed in 20 of 28 patients with HF. Compared with baseline, patients with HFrEF showed significant reduced left atrial volume index (LAVI) and increased right atrial (RA) dimensions, as well as improved LVGLS and RVFWLS, at 6-month follow-up. Despite reduction in LAVI and increase in RA dimensions, improvements in biventricular longitudinal strain did not occur in HFpEF patients. Multivariate logistic regression demonstrated that LVGLS [odds ratio (OR): 5.930; 95% CI: 1.463–24.038; P = 0.013] and RVFWLS (OR: 4.852; 95% CI: 1.372–17.159; P = 0.014) were predictive of improvement in NYHA functional class after D-Shant device implantation.ConclusionImprovements in clinical and functional status are observed in patients with HF 6 months after implantation of a D-Shant device. Preoperative biventricular longitudinal strain is predictive of improvement in NYHA functional class and may be helpful to identify patients who will experience better outcomes following implantation of an interatrial shunt device
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