129 research outputs found

    Managing Uncertainty: An Exploratory Study of Information Seeking Strategies of Online Consumers

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    Uncertainty has been widely recognized as a primary barrier in online C2C transaction processes. This research explores the effectiveness of strategies typically employed to reduce uncertainty in C2C electronic commerce based upon the uncertainty reduction theory and Kelley’s attribution theory. We inspect the effects of the information from four information seeking strategies on online consumers’ perception of uncertainty when initially transacting with an unknown seller in an online marketplace in China; we also integrate the two most prominent contextual factors, information consistency and seller reputation, to explore their direct effects, as well as their interactive effects with information from the four strategies on uncertainty. An online survey is used to collect data from the three most prestigious online store marketplaces in China. The results specify the exact effects of these factors on uncertainty in different contextual conditions. Finally, the theoretical and practical implications of this research are discussed

    Intelligent Agents for Negotiation and Recommendation in Mass Customization

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    Mass customization, as a means to meet individual consumer’s need on a large scale, has recently attracted the attention of both researchers and practitioners. However, as customers and their needs grow increasingly diverse, meeting every consumer’s need has become a surefire way to add unnecessary cost and complexity to operations. Furthermore, consumers are not all really ready for mass customization. They have to face inconveniences such as expensive price, delay delivery and they have to spend time “designing” their product. In order to solve this problem, we proposed a way of intelligent agent assisted negotiation and recommendation. The recommendation is a preference elicitation process, while the negotiation is a communication process based on the situation of manufacturer, such as the inventory level, production cost and lead time. With the aid of intelligent agent of negotiation and recommendation, a good balance between efficiency and customer satisfactions of mass customization can be reached

    Changing Perceptions of Companies’ Website From Foreign to Local: An Experimental Study of Website Localization Strategies

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    Website localization is important for companies to do business in the international market. This paper-in-progress explores website localization strategies and their effects. Drawing from social identity paradigm, we develop two website localization strategies: Similarity strategy (leveraging similarities with local people to positively influence consumer attitude towards foreign companies’ websites in website design) and Prosocial strategy (bringing benefits to local people to enhance consumer attitude towards foreign companies’ websites in website design). We also propose hypotheses about how these two strategies affect perceived website localization, trust and purchase intention through perceived similarity and perceived support. An experimental study will be conducted to validate the hypotheses in Mainland, China

    Near-Infrared (NIR) Luminescent Homoleptic Lanthanide Salen Complexes Ln(4)(Salen)(4) (Ln = Nd, Yb Or Er)

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    The series of homoleptic tetranuclear [Ln(4)(L)(2)(HL)(2)(NO3)(2)(OH)(2)]center dot 2(NO3) (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) have been self-assembled from the reaction of the Salen-type Schiff-base ligand H2L with Ln(NO3)(3)center dot 6H(2)O (Ln = Nd, Yb, Er or Gd), respectively (H2L: N, N'-bis(salicylidene) cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1 and 2 with emissive lifetimes in microsecond ranges are observed and the sensitization arises from the excited state (both (LC)-L-1 and (LC)-L-3) of the Salen-type Schiff-base ligand with the flexible linker.National Natural Science Foundation 21173165, 20871098Ministry of Education of China NCET-10-0936Higher Education of China 20116101110003State Key Laboratory of Structure Chemistry 20100014Education Committee Foundation of Shaanxi Province 11JK0588Hong Kong Research Grants Council, P. R. of China HKBU 202407, FRG/06-07/II-16)Hong Kong Research Grants Council, Robert A. Welch Foundation F-816Texas Higher Education Coordinating Board ARP 003658-0010-2006Petroleum Research Fund 47014-AC5Chemistr

    TRAF3 Negatively Regulates Platelet Activation and Thrombosis

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    CD40 ligand (CD40L), a member of the tumor necrosis factor (TNF) superfamily, binds to CD40, leading to many effects depending on target cell type. Platelets express CD40L and are a major source of soluble CD40L. CD40L has been shown to potentiate platelet activation and thrombus formation, involving both CD40-dependent and -independent mechanisms. A family of proteins called TNF receptor associated factors (TRAFs) plays key roles in mediating CD40L-CD40 signaling. Platelets express several TRAFs. It has been shown that TRAF2 plays a role in CD40L-mediated platelet activation. Here we show that platelet also express TRAF3, which plays a negative role in regulating platelet activation. Thrombin- or collagen-induced platelet aggregation and secretion are increased in TRAF3 knockout mice. The expression levels of collagen receptor GPVI and integrin αIIbβ3 in platelets were not affected by deletion of TRAF3, suggesting that increased platelet activation in the TRAF3 knockout mice was not due to increased expression platelet receptors. Time to formation of thrombi in a FeCl3-induced thrombosis model was significantly shortened in the TRAF3 knockout mice. However, mouse tail-bleeding times were not affected by deletion of TRAF3. Thus, TRAF3 plays a negative role in platelet activation and in thrombus formation in vivo

    Diagnostic and prognostic potential of exosome non-coding RNAs in bladder cancer: a systematic review and meta-analysis

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    BackgroundBladder cancer stands as the predominant malignant tumor in the urological system, presenting a significant challenge to public health and garnering extensive attention. Recently, with the deepening research into tumor molecular mechanisms, non-coding RNAs (ncRNAs) have emerged as potential biomarkers offering guidance for the diagnosis and prognosis of bladder cancer. However, the definitive role of ncRNAs in bladder cancer remains unclear. Hence, this study aims to elucidate the relevance and significance of ncRNAs through a Meta-analysis.MethodsA systematic meta-analysis was executed, including studies evaluating the diagnostic performance of ncRNAs and their associations with overall survival (OS) and disease-free survival (DFS). Key metrics such as hazard ratios, sensitivity, specificity, and diagnostic odds ratios were extracted and pooled from these studies. Potential publication bias was assessed using Deeks’ funnel plot, and the robustness of the results was ascertained through a sensitivity analysis.ResultsElevated ncRNA expression showed a positive correlation with improved OS, evidenced by a hazard ratio (HR) of 0.82 (95% CI: 0.66-0.96, P<0.001). Similarly, a significant association was observed between heightened ncRNA expression and DFS, with an HR of 0.86 (95% CI: 0.73-0.99, P<0.001). Diagnostic performance analysis across 17 articles yielded a pooled sensitivity of 0.76 and a specificity of 0.83. The diagnostic odds ratio was recorded at 2.71, with the area under the ROC curve (AUC) standing at 0.85.ConclusionExosome ncRNAs appear to possess potential significance in the diagnostic and prognostic discussions of bladder cancer. Their relationship with survival outcomes and diagnostic measures suggests a possible clinical utility. Comprehensive investigations are needed to fully determine their role in the ever-evolving landscape of bladder cancer management, especially within the framework of personalized medicine

    Enzyme Kinetics Studies of Nucleoside Diphosphate Kinase in Human Erythrocytes and Frequency Distribution in Healthy Subjects and Transplant Recipients in Chinese Han Population

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    ABSTRACT Nucleoside diphosphate kinase (NDPK), as a house-keeping protein, involves in various molecular processes including signal transduction, energy and drug metabolism. The main objective was to investigate NDPK kinetics in human erythrocytes and to monitor the frequency distribution of NDPK activity levels in Chinese healthy subjects and transplant recipients. METHODS: NDPK activity in erythrocytes was detected by a validated ion-pair high-performance liquid chromatogram method. NDPK kinetics studies were carried out systematically. NDPK activity levels were determined in 500 healthy subjects, 250 kidney and 250 liver transplant recipients in Chinese Han population. RESULTS: Thermal and pH stability studies indicated NDPK was relatively stable at temperature 30-45ÂşC and pH 6.0-9.0. In substrate dependency study, the apparent Michaelis-Menten constant (K m ) and maximum velocity of enzymatic reaction (V max ) increased with concentration of substrates. Meanwhile, in product inhibition study, with the increasing concentration of dATP, the V max of dADP decreased with constant K m and K m of dGTP increased with constant V max . NDPK activity levels revealed a 7-fold variability and were not normally distributed in all groups. NDPK activity levels were significantly (P<0.05) higher in transplant group than those in health group. Additionally, much higher NDPK activity levels had been shown (P<0.001) in liver transplant recipients when compared to kidney transplant cases. CONCLUSIONS: NDPK kinetics studies indicated substrate dependency of NDPK and a "ping-pong" mechanism for production inhibition. Skewness distributions of NDPK activity levels were shown in the study population. The transplant recipients showed higher NDPK activity levels when compared to healthy subjects

    Prediction model of obstructive sleep apnea–related hypertension: Machine learning–based development and interpretation study

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    BackgroundObstructive sleep apnea (OSA) is a globally prevalent disease closely associated with hypertension. To date, no predictive model for OSA-related hypertension has been established. We aimed to use machine learning (ML) to construct a model to analyze risk factors and predict OSA-related hypertension.Materials and methodsWe retrospectively collected the clinical data of OSA patients diagnosed by polysomnography from October 2019 to December 2021 and randomly divided them into training and validation sets. A total of 1,493 OSA patients with 27 variables were included. Independent risk factors for the risk of OSA-related hypertension were screened by the multifactorial logistic regression models. Six ML algorithms, including the logistic regression (LR), the gradient boosting machine (GBM), the extreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), bootstrapped aggregating (Bagging), and the multilayer perceptron (MLP), were used to develop the model on the training set. The validation set was used to tune the model hyperparameters to determine the final prediction model. We compared the accuracy and discrimination of the models to identify the best machine learning algorithm for predicting OSA-related hypertension. In addition, a web-based tool was developed to promote its clinical application. We used permutation importance and Shapley additive explanations (SHAP) to determine the importance of the selected features and interpret the ML models.ResultsA total of 18 variables were selected for the models. The GBM model achieved the most extraordinary discriminatory ability (area under the receiver operating characteristic curve = 0.873, accuracy = 0.885, sensitivity = 0.713), and on the basis of this model, an online tool was built to help clinicians optimize OSA-related hypertension patient diagnosis. Finally, age, family history of hypertension, minimum arterial oxygen saturation, body mass index, and percentage of time of SaO2 < 90% were revealed by the SHAP method as the top five critical variables contributing to the diagnosis of OSA-related hypertension.ConclusionWe established a risk prediction model for OSA-related hypertension patients using the ML method and demonstrated that among the six ML models, the gradient boosting machine model performs best. This prediction model could help to identify high-risk OSA-related hypertension patients, provide early and individualized diagnoses and treatment plans, protect patients from the serious consequences of OSA-related hypertension, and minimize the burden on society

    Pediatric myelin oligodendrocyte glycoprotein antibody-associated disease in southern China: analysis of 93 cases

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    ObjectiveTo study the clinical features of children diagnosed with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in southern China.MethodsClinical data of children diagnosed with MOGAD from April 2014 to September 2021 were analyzed.ResultsA total of 93 children (M/F=45/48; median onset age=6.0 y) with MOGAD were involved. Seizures or limb paralysis was the most common onset or course symptom, respectively. The most common lesion locations in brain MRI, orbital MRI, and spinal cord MRI were basal ganglia and subcortical white matter, the orbital segment of the optic nerve, and the cervical segment, respectively. ADEM (58.10%) was the most common clinical phenotype. The relapse rate was 24.7%. Compared with the patients without relapse, relapsed patients had a longer interval from onset to diagnosis (median: 19 days VS 20 days) and higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer positively persistent (median: 3 months VS 24 months). All patients received IVMP plus IVIG at the acute phase, and 96.8% of patients achieved remission after one to three courses of treatment. MMF, monthly IVIG, and maintaining a low dose of oral prednisone were used alone or in combination as maintenance immunotherapy for relapsed patients and effectively reduced relapse. It transpired 41.9% of patients had neurological sequelae, with movement disorder being the most common. Compared with patients without sequelae, patients with sequelae had higher MOG antibody titer at onset (median: 1:32 VS 1:100) with longer persistence (median: 3 months VS 6 months) and higher disease relapse rate (14.8% VS 38.5%).ConclusionsResults showed the following about pediatric MOGAD in southern China: the median onset age was 6.0 years, with no obvious sex distribution difference; seizure or limb paralysis, respectively, are the most common onset or course symptom; the lesions of basal ganglia, subcortical white matter, the orbital segment of the optic nerve, and cervical segment were commonly involved in the CNS MRI; ADEM was the most common clinical phenotype; most had a good response to immunotherapy; although the relapse rate was relatively high, MMF, monthly IVIG and a low dose of oral prednisone might effectively reduce relapse; neurological sequelae were common, and possibly associated with MOG antibody status and disease relapse
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