194 research outputs found
A user preference perception model using data mining on a Web-based Environment
In a competitive environment, how to provide the information and products to meet the requirements of customers and improve the customer satisfaction will be the key criteria to measure a company’s competitiveness. Customer Relationship Management (CRM) becomes an important issue in any business market gradually. Using information technology, businesses can achieve their requirements for one to one marketing more efficiently with lower cost, labor and time.
In this paper, we proposed a user preference perception model by using data mining technology on a web-based environment. First, the users’ web browse records are aggregated. Second, fuzzy set theory and most sequential pattern mining algorithm are used to infer the users’ preference changes in a period. After the test had processed, we use the on-line questionnaire to investigate the customer satisfaction degree from all participators. The results show that the degree of satisfaction was up to 72% for receiving the new information of participants whose preferences had been changed. It indicates that the proposed system can effectively perceive the change of preference for users on a web environment
Tailoring excitonic states of van der Waals bilayers through stacking configuration, band alignment and valley-spin
Excitons in monolayer semiconductors have large optical transition dipole for
strong coupling with light field. Interlayer excitons in heterobilayers, with
layer separation of electron and hole components, feature large electric dipole
that enables strong coupling with electric field and exciton-exciton
interaction, at the cost that the optical dipole is substantially quenched (by
several orders of magnitude). In this letter, we demonstrate the ability to
create a new class of excitons in transition metal dichalcogenide (TMD) hetero-
and homo-bilayers that combines the advantages of monolayer- and
interlayer-excitons, i.e. featuring both large optical dipole and large
electric dipole. These excitons consist of an electron that is well confined in
an individual layer, and a hole that is well extended in both layers, realized
here through the carrier-species specific layer-hybridization controlled
through the interplay of rotational, translational, band offset, and
valley-spin degrees of freedom. We observe different species of such
layer-hybridized valley excitons in different heterobilayer and homobilayer
systems, which can be utilized for realizing strongly interacting
excitonic/polaritonic gases, as well as optical quantum coherent controls of
bidirectional interlayer carrier transfer either with upper conversion or down
conversion in energy
Association between health examination items and body mass index among school children in Hualien, Taiwan
BACKGROUND: To assess the prevalence of obesity and major physical examination items including dental caries, myopia, pinworm, hematuria, and proteinuria among school children in Hualien, Taiwan. In addition, the health status differences between gender, grader, levels of residence urbanization, and body mass index (BMI) were examined. METHODS: Cross-sectional studies with a total of 11,080 students (age, 7–14 years) in grades 1, 4, and 7 were evaluated for weight, height, routine physical examination, and urine analysis during the 2010 Student Health Examination in Hualien. Frequencies, Chi-square test, and logistic regression were conducted using SPSS. RESULTS: Of the 11,080 students evaluated, 1357 (12.2%) were overweight, and 1421 (12.8%) were obese. There were significant differences in overweight/obese prevalence by gender, by grader, and by levels of residence urbanization. Dental caries, myopia, and obesity were the most prevalent health problems among these students (75.6%, 33.0%, and 12.8%, respectively). In crude and adjusted analyses, research results showed that there were significant differences in the prevalence of major physical examination items between different gender, grader, levels of residence urbanization, and BMI groups. Girls had a higher prevalence of dental caries, myopia, and hematuria than boys (all p < 0.01), whereas boys had a higher prevalence of pinworm than girls (p = 0.02). Students in higher grades had significantly higher prevalence of myopia, hematuria, and proteinuria (all p < 0.01), whereas students in lower grades had higher prevalence of dental caries and pinworm (p < 0.01). Students with abnormal BMI had lower prevalence of pinworm (p < 0.01). Students residing in suburban and rural areas had higher prevalence of dental caries, pinworm, and hematuria (all p < 0.01), and lower prevalence of myopia than students residing in urban areas (all p < 0.01). CONCLUSION: Routine health examination provides an important way to detect students’ health problems. Our study elucidated major health problems among school children in Hualien, Taiwan. In addition, the results also indicated that the prevalence of health problems had a significant relationship with gender, grader, levels of residence urbanization, and BMI. It is suggested that school health interventions should consider students’ health profiles along with their risk factors status in planning
A predicted protein, KIAA0247, is a cell cycle modulator in colorectal cancer cells under 5-FU treatment
<p>Abstract</p> <p>Background</p> <p>Colorectal cancer (CRC) is the predominant gastrointestinal malignancy and the leading cause of cancer death. The identification of genes related to CRC is important for the development of successful therapies and earlier diagnosis.</p> <p>Methods</p> <p>Molecular analysis of feces was evaluated as a potential method for CRC detection. Expression of a predicted protein with unknown function, KIAA0247, was found in feces evaluated using specific quantitative real-time polymerase chain reaction. Its cellular function was then analyzed using immunofluorescent staining and the changes in the cell cycle in response to 5-fluorouracil (5-FU) were assessed.</p> <p>Results</p> <p>Gastrointestinal tissues and peripheral blood lymphocytes ubiquitously expressed KIAA0247. 56 CRC patients fell into two group categories according to fecal KIAA0247 mRNA expression levels. The group with higher fecal KIAA0247 (<it>n </it>= 22; ≥ 0.4897) had a significantly greater five-year overall survival rate than the group with lower fecal KIAA0247 (<it>n </it>= 30; < 0.4897) (66.0 ± 11.6%; <it>p </it>= 0.035, log-rank test). Fecal expression of KIAA0247 inversely related to CRC tumor size (Kendall's tau-b = -0.202; <it>p </it>= 0.047). Immunofluorescent staining revealed that the cytoplasm of CRC cells evenly expresses KIAA0247 without 5-FU treatment, and KIAA0247 accumulates in the nucleus after 40 μM 5-FU treatment. In HCT116 p53<sup>-/- </sup>cells, which lack p53 cell cycle control, the proportion of cells in the G2/M phase was larger (13%) in KIAA0247-silent cells than in the respective shLuc control (10%) and KIAA0247-overexpressing cells (7%) after the addition of low dose (40 μM) 5-FU. Expression of three cyclin genes (cyclin A2, cyclin B1, and cyclin B2) also downregulated in the cells overexpressing KIAA0247.</p> <p>Conclusions</p> <p>This is the first description of a linkage between KIAA0247 and CRC. The study's data demonstrate overexpression of KIAA0247 associates with 5-FU therapeutic benefits, and also identify the clinical significance of fecal KIAA0247 in CRC.</p
Assessing the Decision-Making Process in Human-Robot Collaboration Using a Lego-like EEG Headset
Human-robot collaboration (HRC) has become an emerging field, where the use of a robotic agent has been shifted from a supportive machine to a decision-making collaborator. A variety of factors can influence the effectiveness of decision-making processes during HRC, including the system-related (e.g., robot capability) and human-related (e.g., individual knowledgeability) factors. As a variety of contextual factors can significantly impact the human-robot decision-making process in collaborative contexts, the present study adopts a Lego-like EEG headset to collect and examine human brain activities and utilizes multiple questionnaires to evaluate participants’ cognitive perceptions toward the robot. A user study was conducted where two levels of robot capabilities (high vs. low) were manipulated to provide system recommendations. The participants were also identified into two groups based on their computational thinking (CT) ability. The EEG results revealed that different levels of CT abilities trigger different brainwaves, and the participants’ trust calibration of the robot also varies the resultant brain activities
Ultrafast Laser Ablation, Intrinsic Threshold, and Nanopatterning of Monolayer Molybdenum Disulfide
Laser direct writing is an attractive method for patterning 2D materials
without contamination. Literature shows that the femtosecond ablation threshold
of graphene across substrates varies by an order of magnitude. Some attribute
it to the thermal coupling to the substrates, but it remains by and large an
open question. For the first time the effect of substrates on femtosecond
ablation of 2D materials is studied using MoS as an example. We show
unambiguously that femtosecond ablation of MoS is an adiabatic process
with negligible heat transfer to the substrates. The observed threshold
variation is due to the etalon effect which was not identified before for the
laser ablation of 2D materials. Subsequently, an intrinsic ablation threshold
is proposed as a true threshold parameter for 2D materials. Additionally, we
demonstrate for the first time femtosecond laser patterning of monolayer
MoS with sub-micron resolution and mm/s speed. Moreover, engineered
substrates are shown to enhance the ablation efficiency, enabling patterning
with low-power femtosecond oscillators. Finally, a zero-thickness approximation
is introduced to predict the field enhancement with simple analytical
expressions. Our work clarifies the role of substrates on ablation and firmly
establishes femtosecond laser ablation as a viable route to pattern 2D
materials
Unveiling Defect-Mediated Carrier Dynamics in Monolayer Semiconductors by Spatiotemporal Microwave Imaging
The optoelectronic properties of atomically thin transition-metal
dichalcogenides are strongly correlated with the presence of defects in the
materials, which are not necessarily detrimental for certain applications. For
instance, defects can lead to an enhanced photoconduction, a complicated
process involving charge generation and recombination in the time domain and
carrier transport in the spatial domain. Here, we report the simultaneous
spatial and temporal photoconductivity imaging in two types of WS2 monolayers
by laser-illuminated microwave impedance microscopy. The diffusion length and
carrier lifetime were directly extracted from the spatial profile and temporal
relaxation of microwave signals respectively. Time-resolved experiments
indicate that the critical process for photo-excited carriers is the escape of
holes from trap states, which prolongs the apparent lifetime of mobile
electrons in the conduction band. As a result, counterintuitively, the
photoconductivity is stronger in CVD samples than exfoliated monolayers with a
lower defect density. Our work reveals the intrinsic time and length scales of
electrical response to photo-excitation in van der Waals materials, which is
essential for their applications in novel optoelectronic devices.Comment: 21 pages, 4 figure
Pathological granuloma fibrosis induced by agar-embedded Mycobacterium abscessus in C57BL/6JNarl mice
IntroductionPulmonary granuloma diseases caused by Mycobacterium abscessus (M. abscessus) have increased in past decades, and drug-resistance in this pathogen is a growing public health concern. Therefore, an animal model of chronic granuloma disease is urgently needed.MethodsIn this study, M. abscessus embedded within agar beads (agar-AB) was used to develop such a model in C57BL/6JNarl mice.ResultsChronic infection was sustained for at least 3 months after agar-AB infection, visible granulomas spread in the lungs, and giant cells and foamy cells appeared in the granulomas. More importantly, pulmonary fibrosis progressed for 3 months, and collagen fibers were detected by Masson trichrome staining. Further, inducible nitric oxide synthase (iNOS) was highly expressed within the alveolar space, and the fibrosis-mediator transforming growth factor beta (TGF-β) began to be expressed at 1 month. Hypoxia-inducible factor (HIF-1α) expression also increased, which aided in normalizing oxygen partial pressure.DiscussionAlthough the transient fibrosis persisted for only 3 months, and the pulmonary structure resolved when the pathogen was cleard, this pulmonary fibrosis model for M. abscessus infection will provide a novel test platform for development of new drugs, regimens, and therapies
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