1,071 research outputs found
Temporal Analysis of Language through Neural Language Models
We provide a method for automatically detecting change in language across
time through a chronologically trained neural language model. We train the
model on the Google Books Ngram corpus to obtain word vector representations
specific to each year, and identify words that have changed significantly from
1900 to 2009. The model identifies words such as "cell" and "gay" as having
changed during that time period. The model simultaneously identifies the
specific years during which such words underwent change
Observation of interlayer phonon modes in van der Waals heterostructures
We have investigated the vibrational properties of van der Waals
heterostructures of monolayer transition metal dichalcogenides (TMDs),
specifically MoS2/WSe2 and MoSe2/MoS2 heterobilayers as well as twisted MoS2
bilayers, by means of ultralow-frequency Raman spectroscopy. We discovered
Raman features (at 30 ~ 40 cm-1) that arise from the layer-breathing mode (LBM)
vibrations between the two incommensurate TMD monolayers in these structures.
The LBM Raman intensity correlates strongly with the suppression of
photoluminescence that arises from interlayer charge transfer. The LBM is
generated only in bilayer areas with direct layer-layer contact and atomically
clean interface. Its frequency also evolves systematically with the relative
orientation between of the two layers. Our research demonstrates that LBM can
serve as a sensitive probe to the interface environment and interlayer
interactions in van der Waals materials
A Study of Online Customer Loyalty Based on the Theory of Planned Behavior
The Internet has introduced major changes in the way companies conduct business. Practically, rising numbers of customers are using the Internet for Electronic Commerce (EC). In the respect of customer relationship, Business-to-Consumer (B2C) EC provides ongoing information, service, and support that have changed the approaches of communication and interaction with customers. The nature of online customer behavior in the EC transaction is therefore different from the one in a traditional retailing channel. This research focuses on the online customer behavior through examining the relationship between the behavior intention and the online behavior itself. Based on the Theory of Planned Behavior (TPB), a base model of Online Customer Loyalty is developed. The research also proposes an alternative model in which Satisfaction is adopted as a mediated variable. Four hundred and twenty-three questionnaires are collected for the empirical experiment. The method of Structural Equation Modeling (SEM) is used to evaluate the measurement and structural models. The result indicates that TPB can be used to explain the behavior of Online Customer Loyalty. The structure relationship between Behavior Intention and Online Customer Loyalty is significant. The three constructs influencing Behavior Intention including Attitude toward Behavior, Subjective Norm and Perceived Behavioral Control also have indirectly positive effects on the behavior of Online Customer Loyalty. The two competing models are compared. Both models are acceptable when judged by the criteria of goodness-of-fit measures. However, the alternative model has a higher explained proportion of variance in Online Customer Loyalty
Early utilization of hypertonic peritoneal dialysate and subsequent risks of non-traumatic amputation among peritoneal dialysis patients: a nationwide retrospective longitudinal study
BACKGROUND: The hemodialysis (HD) population has a particularly high incidence of amputation, which is likely associated with decreased tissue oxygenation during HD. However, information about the risk factors leading to amputation in peritoneal dialysis (PD) patients is limited. Here, we have investigated the association between the use of hypertonic peritoneal dialysate (HPD) and subsequent amputation in PD patients. METHODS: Based on the data from the Taiwan National Health Insurance research database, this observational cohort study enrolled 203 PD patients who had received HPD early during treatment and had not undergone amputation and 296 PD controls who had not undergone amputation. Subjects were followed through until the end of 2009 and the event rates of new non-traumatic amputation were compared between groups. RESULTS: The incidence of amputation was 3 times higher for the HPD cohort than for the comparison cohort (23.68 vs. 8.01 per 1000 person-years). The hazard ratio (HR) for this group, estimated using a multivariable Cox model, was 2.48 (95% confidence interval [CI] = 1.06–5.79). The HR for patients with both diabetes and early adoption of HPD increased to 44.34 (95% CI = 5.51-357.03), compared to non-HPD non-diabetic PD controls. CONCLUSION: Early utilization of HPD in PD patients is associated with increasing risk of amputation; this risk considerably increases for those with concomitant diabetes
Persistence of Japanese Encephalitis Virus Is Associated with Abnormal Expression of the Nonstructural Protein NS1 in Host Cells
AbstractPersistent infection with Japanese encephalitis virus (JEV) was established in murine neuroblastoma N18 cells, and the persistency has been maintained in cell culture for over 6 months. From the persistently infected cells, a clone named C2-2 was selected and expanded to form a stable cell line. The vast majority of C2-2 cells showed viral protein staining by immunofluorescence and continuously produced low levels of virus (103to 104PFU/ml) without marked cytopathic effects or cyclic variations. In addition to the wild-type viral proteins, truncated forms of the viral nonstructural protein 1 (NS1) as well as its derivative NS1′ were produced in C2-2 cells. Both truncated NS1 and NS1′ contain deletions at their N-termini; however, the analyses by RT–PCR and direct sequencing of the viral RNA failed to detect any truncations or mutations within the NS1 region, suggesting that NS1 truncation was a result of a unique posttranslational proteolytic cleavage of NS1 in the persistently infected cells. Similar but not identical truncation of NS1 was also observed in two other persistently infected cell lines established in Vero and DBT (murine astrocytoma) cells. However, viruses released from C2-2 cells did not produce truncated NS1 upon infection of N18 cells, suggesting that NS1 truncations were the result of virus–cell interaction in persistently infected cells. These data indicate a strong association between abnormal NS1 expression and JEV persistency. A probable involvement of dysfunctional NS1 in the establishment and/or maintenance of JEV persistency in tissue culture is discussed
The Parameters Optimizing Design of Double Suspension Arm Torsion Bar in the Electric Sight-Seeing Car by Random Vibration Analyzing Method
This study is about the impact of the performance and the sensitivity analysis for parameters of the torsion bar suspension in the electric sight-seeing car, which the authors’ laboratory designed and which is used in the authors’ university. The suspension stiffness was calculated by using the virtual work principle, the vector algebra, and tensor of finite rotation methods and was verified by the ADAMS software. Based on the random vibration analysis method, the paper analyzed the dynamic tire load (DTL), suspension working space (SWS), and comfort performance parameters. For the purpose of decreasing the displacement of the suspension and limiting the frequency of impacting the stop block, the paper examined the three parameters and optimized the basic parameters of the torsion bar. The results show that the method achieves a great effect and contributes an accurate value for the general layout design
A novel deep intronic variant strongly associates with Alkaptonuria.
Alkaptonuria is a rare autosomal recessive inherited disorder of tyrosine metabolism, which causes ochronosis, arthropathy, cardiac valvular calcification, and urolithiasis. The epidemiology of alkaptonuria in East Asia is not clear. In this study, patients diagnosed with alkaptonuria from January 2010 to June 2020 were reviewed. Their clinical and molecular features were further compared with those of patients from other countries. Three patients were found to have alkaptonuria. Mutation analyses of the homogentisate 1,2-dioxygenase gene (HGD) showed four novel variants c.16-2063 A > C, p.(Thr196Ile), p.(Gly344AspfsTer25), and p.(Gly362Arg) in six mutated alleles (83.3%). RNA sequencing revealed that c.16-2063 A > C activates a cryptic exon, causing protein truncation p.(Tyr5_Ile6insValTer17). A literature search identified another 6 patients with alkaptonuria in East Asia; including our cases, 13 of the 18 mutated alleles have not been reported elsewhere in the world. Alkaptonuria is rare in Taiwan and East Asia, with HGD variants being mostly novel and private
Genome-wide analysis of copy number variations identifies PARK2 as a candidate gene for autism spectrum disorder
Effects of human parvovirus B19 VP1 unique region protein on macrophage responses
<p>Abstract</p> <p>Background</p> <p>Activity of secreted phospholipase A (sPLA2) has been implicated in a wide range of cellular responses. However, little is known about the function of human parvovirus B19-VP1 unique region (VP1u) with sPLA2 activity on macrophage.</p> <p>Methods</p> <p>To investigate the roles of B19-VP1u in response to macrophage, phospholipase A2 activity, cell migration assay, phagocytosis activity, metalloproteinase assay, RT-PCR and immunoblotting were performed.</p> <p>Results</p> <p>In the present study, we report that migration, phagocytosis, IL-6, IL-1β mRNA, and MMP9 activity are significantly increased in RAW264.7 cells by B19-VP1u protein with sPLA2 activity, but not by B19-VP1uD175A protein that is mutated and lacks sPLA2 activity. Additionally, significant increases of phosphorylated ERK1/2 and JNK proteins were detected in macrophages that were treated with B19-VP1u protein, but not when they were treated with B19-VP1uD175A protein.</p> <p>Conclusion</p> <p>Taken together, our experimental results suggest that B19-VP1u with sPLA2 activity affects production of IL-6, IL-1β mRNA, and MMP9 activity, possibly through the involvement of ERK1/2 and JNK signaling pathways. These findings could provide clues in understanding the role of B19-VP1u and its sPLA2 enzymatic activity in B19 infection and B19-related diseases.</p
Risk factors for poor outcomes of children with acute acalculous cholecystitis
BACKGROUND: Acute acalculous cholecystitis (AAC) is generally considered to be a mild disease in children; however, if left untreated or treated without caution, AAC can lead to severe outcomes, such as death. The objectives of this study were to present the clinical features and identify the predictors of mortality in pediatric AAC. METHODS: Patients diagnosed with AAC between 2005 and 2012 were enrolled. AAC was defined by the presence of fever and an echo-proven thickened gallbladder wall exceeding 4 mm. A poor health outcome was defined as death. Further information related to the demographics, clinical manifestations, laboratory results, ultrasound findings, and pathogens present in the AAC patients was also collected. Predictors of mortality were identified by association analyses and confirmed by multivariate logistic regression. RESULTS: A total of 147 pediatric AAC patients (male/female = 1.01, mean age = 5.2 years) were included in this retrospective study. The most common clinical presentation was an elevated C-reactive protein level (84%) followed by hepatomegaly (80%) and anorexia (78%). AAC in children was associated with various diseases, including infectious diseases (70%), systemic diseases (13%), and malignancy (11%). Fourteen of the 147 (9.25%) patients died during the study period. The presences of thrombocytopenia, anemia, gallbladder sludge, hepatitis, and/or sepsis plus hepatitis were found to be the important predictors of AAC mortality. CONCLUSIONS: The factors associated with AAC mortality were anemia, thrombocytopenia, gallbladder sludge, hepatitis, and sepsis plus hepatitis. These predictors are likely to help clinicians identify patients who are at a high risk of poor prognoses and make appropriate clinical decisions
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