211 research outputs found
User Needs Mining Based on Topic Analysis of Online Reviews
The purpose of this paper is to aggregate the topic information of online review text and clarify the user needs. We conducted the study on online reviews of women’s clothing store of Taobao.com with semantic analysis and text mining. Online reviews were collected by means of web crawler. Using Chinese word segmentation tool and data analysis tool, the word frequency statistics was realized. The statistical software was used for the clustering analysis and multidimensional scaling analysis of high frequency keywords. The results show that the content of online reviews mainly includes four topics: basic features of products, additional features of products, user experience and product display. It reveals the potential user needs of women’s clothing store of Taobao.com, which cannot only help consumers to make rational decisions, but also provide guidance to merchants and manufacturers
Survivin is Required for Mouse and Human Bone Marrow Mesenchymal Stromal Cell Function
Although mesenchymal stromal cells (MSCs) have significant potential in cell-based therapies, little is known about the factors that regulate their functions. While exploring regulatory molecules potentially involved in MSC activities, we found that the endogenous multifunctional factor Survivin is essential for MSC survival, expansion, lineage commitment, and migration. Pharmacological or genetic blockade of Survivin expression in mouse and human bone marrow MSC enhances caspase 3 and 7 expression and reduces proliferation resulting in fewer MSC and clonogenic colony-forming unit-fibroblasts (CFU-F), whereas ectopic Survivin overexpression in MSC results in their expansion. Survivin is also required for the MSC proliferative responses to basic fibroblast growth factor and platelet derived growth factor. In a wound healing model, Survivin inhibition results in suppression of MSC migration to the wound site. In addition, loss of Survivin in MSCs compromises their hematopoiesis-supporting capacity. These results demonstrate that Survivin is a key regulator of mouse and human MSC function, and suggest that targeted modulation of Survivin in MSCs may have clinical utility to enhance MSC recovery and activity following insult or stress
Exploring college students’ continuance learning intention in data analysis technology courses: the moderating role of self-efficacy
IntroductionIn today’s digital economy, data resources have gained strategic recognition. Enterprises view data analytic capabilities as a core organizational competitiveness. This study explored factors influencing college students’ continuance learning intention in data analysis technology courses to inform the role of self-efficacy on the relationship between interactivity and continuance learning intention.MethodsThe research model underpinning the study was based on the Stimulus-Organism-Response model and flow theory. The model was validated using SmartPLS. A total of 314 valid questionnaires were collected via the standard online survey approach.ResultsAmong internal factors, study results showed both cognitive interest and self-efficacy had significant positive effects on continuance learning intention. Also, cognitive interest had a significant positive effect on self-efficacy. Among external stimuli, content quality, software quality, and interactivity had significant positive effects on self-efficacy. Software quality did not have a significant effect on cognitive interest. Importantly, self-efficacy registered a significant moderating role on the relationship between interactivity and continuance learning intention
A Stable Cranial Neural Crest Cell Line from Mouse
Cranial neural crest cells give rise to ectomesenchymal derivatives such as cranial bones, cartilage, smooth
muscle, dentin, as well as melanocytes, corneal endothelial cells, and neurons and glial cells of the peripheral
nervous system. Previous studies have suggested that although multipotent stem-like cells may exist during the
course of cranial neural crest development, they are transient, undergoing lineage restriction early in embryonic
development. We have developed culture conditions that allow cranial neural crest cells to be grown as multipotent
stem-like cells. With these methods, we obtained 2 independent cell lines, O9-1 and i10-1, which were
derived from mass cultures of Wnt1-Cre; R26R-GFP-expressing cells. These cell lines can be propagated and
passaged indefinitely, and can differentiate into osteoblasts, chondrocytes, smooth muscle cells, and glial cells.
Whole-genome expression profiling of O9-1 cells revealed that this line stably expresses stem cell markers (CD44,
Sca-1, and Bmi1) and neural crest markers (AP-2α, Twist1, Sox9, Myc, Ets1, Dlx1, Dlx2, Crabp1, Epha2, and Itgb1).
O9-1 cells are capable of contributing to cranial mesenchymal (osteoblast and smooth muscle) neural crest fates when injected into E13.5 mouse cranial tissue explants and chicken embryos. These results suggest that O9-1 cells represent multipotent mesenchymal cranial neural crest cells. The O9-1 cell line should serve as a useful tool for investigating the molecular properties of differentiating cranial neural crest cells
What Are the New Challenges of the Current Cancer Biomarkers?
Biomarkers are emerging research filed in the past decade. Even though numerous biomarkers were reported, the efficiency of cancer therapy remains low. So the question emerges as to how much can we trust the current biomarkers on cancer therapy? In this upcoming chapter, we would like to illustrate the outcomes of classical cancer therapies on advanced pancreatic cancer disclosed successful, neutral and failed in clinical trials. The analysis will be carried on the perspective interdisciplinary on the biomarkers including anatomy, physiology, pharmacology, biochemistry, history path and development of pharmacy. Particular in-depth insight may open a window for new researches and lighting the therapies
Screening and identification of Bifidobacterium longum from maternal milk and its domestication of oxygen-domestication
Objective: To screen Bifidobacterium from breast milk and improve its oxygen tolerance under aerobic conditions. Methods: Dilution and spread plate methods were performed to separate and screen Bifidobacterium from breast milk. Their Bifidobacterium identifications were characterized by 16S rDNA sequencing. The oxygen tolerant domestications were conducted through gradual increase of oxygen pressure and alternation of aerobic and anaerobic cultivations. Results: A novel Bifidobacterium strain was isolated from human milk and was identified as Bifidobacterium longum by 16S rDNA sequencing, which was named as MEFZ-2201. The homology between MEFZ-2201 and model strain (accession number in NCBI: ON631733.1) reached 100%. After oxygen tolerant domestication, the highest viable bacteria number of Bifidobacterium longum MEFZ-2201d in aerobic cultivation reached 8.9Ă—109 CFU/mL, which was ten times higher than that of its wild-type strain MEFZ-2201. Whereas, the morphological property and physio-biochemical characteristics of Bifidobacterium longum MEFZ-2201d did not change after oxygen tolerant domestication. The short-chain fatty acid production of domesticated strain Bifidobacterium longum MEFZ-2201d was also significantly higher than that of its wild-type strain even under anaerobic conditions. Conclusion: A novel Bifidobacterium longum strain MEFZ-2201 was isolated from breast milk. The viable bacterium number of its domesticated strain MEFZ-2201d was significantly increased under aerobic conditions, indicating that it would be a potential probiotic strain for further development and utilization
Characterization of cellulase production by carbon sources in two Bacillus species
The induction of cellulase production in two Bacillus spp. was studied by means of measuring cellulase activities under the condition of different carbon sources. The results indicate that cellulase could not be induced by cellulose material as a sole carbon source. Instead, they could be induced by monosaccharide or disaccharide with reducing group. Moreover, the expression of cellulase components was synergistic. When cell wall/envelope enzyme and endoenzyme from two Bacillus spp. acted on these inducers, analysis of reaction products by high performance liquid chromatography (HPLC) revealed that cell wall/envelope enzyme and endoenzyme from two Bacillus spp. were inactive on these inducers. It also indicated that these inducers entered cells directly and served function of induction.Keywords: Bacillus, cellulase, induction, carbon source
Doping the Buckminsterfullerene by Substitution: Density Functional Theory Studies of C 59
The heterofullerenes C59X (X = B, N, Al, Si, P, Ga, Ge, and As) were investigated by quantum chemistry calculations based on density functional theory. These hybrid cages can be seen as doping the buckminsterfullerene by heteroatom substitution. The geometrical structures, relative stabilities, electronic properties, vibrational frequencies, dielectric constants, and aromaticities of the doped cages were studied systemically and compared with those of the pristine C60 cage. It is found that the doped cages with different heteroatoms exhibit various electronic, vibrational, and aromatic properties. These results imply the possibility to modulate the physical properties of these fullerene-based materials by tuning substitution elements
Rapid Mobilization Reveals a Highly Engraftable Hematopoietic Stem Cell
Hematopoietic stem cell transplantation is a potential curative therapy for malignant and nonmalignant diseases. Improving the efficiency of stem cell collection and the quality of the cells acquired can broaden the donor pool and improve patient outcomes. We developed a rapid stem cell mobilization regimen utilizing a unique CXCR2 agonist, GROβ, and the CXCR4 antagonist AMD3100. A single injection of both agents resulted in stem cell mobilization peaking within 15 min that was equivalent in magnitude to a standard multi-day regimen of granulocyte colony-stimulating factor (G-CSF). Mechanistic studies determined that rapid mobilization results from synergistic signaling on neutrophils, resulting in enhanced MMP-9 release, and unexpectedly revealed genetic polymorphisms in MMP-9 that alter activity. This mobilization regimen results in preferential trafficking of stem cells that demonstrate a higher engraftment efficiency than those mobilized by G-CSF. Our studies suggest a potential new strategy for the rapid collection of an improved hematopoietic graft
Evaluation of preoperative intra-aortic balloon pump in coronary patients with severe left ventricular dysfunction undergoing OPCAB surgery: early and mid-term outcomes
<p>Abstract</p> <p>Background</p> <p>The purpose of the present study was to evaluate the safety and the cost-effectiveness of using preoperative IABP as support compared with postoperative IABP treatment in coronary patients with severe left ventricular dysfunction (SLVD) who is undergoing off-pump coronary artery bypass surgery (OPCAB), including early outcomes, hospital mortality and morbidity, and mid-term follow-up outcomes.</p> <p>Methods</p> <p>Between March 2000 and December 2008, we prospectively and randomly studied the insertion of preoperative IABP in 115 (7.4%) and postoperative IABP in 106 (6.8%) of the 1560 consecutive patients. Group A is preoperative IABP therapy. Group B is postoperative IABP therapy.</p> <p>Results</p> <p>There was no significant difference in the number of grafts used between the two groups. Completeness of revascularization did not differ between the two groups. The statistically significant difference was hospital mortality (2.6% in group A vs. 3.8% in group B) (<it>p </it>< 0.05). And there was significant reduction in postoperative low cardiac output, malignant arrhythmia, acute renal failure and length of stay in ICU in group A, compared with group B (<it>p </it>< 0.05). In the two groups, six-, 12-, 24- and 48-month survival rates were similar. In the study the degree of improvement in angina and quality of life did not differ significantly between the two groups.</p> <p>Conclusion</p> <p>The use of preoperative IABP in SLVD patients undergoing OPCAB is of safety and effectiveness. The combined use of preoperative IABP and OPCAB allows complete revascularization in SLVD patients with an important reduction in operative mortality and excellent mid-term results.</p
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