In this study, facile salt-assisted chemical vapor deposition (CVD) was used to synthesize ultrathin non-van der Waals chromium sulfide (Cr2S3) with a thickness of ∼1.9 nm. The structural transformation of as-grown Cr2S3 was studied using advanced in situ heating techniques combined with transmission electron microscopy (TEM). Two-dimensional (2D) and quasi-one-dimensional (1D) samples were fabricated to investigate the connection between specific planes and the dynamic behavior of the structural variation. The rearrangement of atoms during the phase transition was driven by the loss of sulfur atoms at elevated temperatures, resulting in increased free energy. A decrease in the ratio of the (001) plane led to an overall increase in surface energy, thus lowering the critical phase transition temperature. Our study provides detailed insight into the mechanism of structural transformation and the critical factors governing transition temperature, thus paving the way for future studies on intriguing Cr-S compounds.
Dedicated short range communication (DSRC) is the key component in intelligent transportation systems (ITS). The goal of this technology is to help driver and passengers getting multimedia services via wireless communication equipment during the movement of vehicle, so as to improve the traffic safety and enhance the transportation efficiency. The paper is focus on the DSRC baseband technical analysis and the application development. Based on the WLAN 802.11a architecture, we develop a new adaptive channel estimation algorithm that uses two kinds of feedback tracking and pilot aid to enhance wireless access ability in vehicular environments.
Environmental tobacco smoke (ETS) contains relatively high concentrations of polycyclic aromatic hydrocarbons (PAHs). Urinary 1‐hydroxypyrene (1‐OHP), a metabolite of pyrene, is a good indicator of PAH exposure in occupational studies. In this study, we investigated the relationship between urinary 1‐OHP concentration and ETS exposure in preschool children. Forty preschool children, aged 24‐76 months, were studied during November and December, 1999. Two spot‐urine specimens (one in the morning immediately after the subject woke up and the other at night before the subject went to bed) were collected 1 day after completion of a questionnaire, in order to determine 1‐OHP concentrations by fluorescent spectrophotometry. Overall, urinary 1‐OHP concentrations were relatively low but detectable (morning: median, 0.021 μg/g creatinine; range, 0.002‐1.019 μg/g creatinine; night: median, 0.015 μg/g creatinine; range, 0.002‐1.328 μg/g creatinine). Multiple linear regression analyses revealed that the total number of cigarettes smoked by the children's fathers during the 3 days prior to collection of the urine specimens was significantly associated with their urinary 1‐OHP concentrations, after adjusting for other confounders. Each cigarette smoked by a child's father resulted in an average 9.6% increase in 1‐OHP concentration in the morning urine specimen (95% confidence interval = 1.8‐18.1%; p = 0.02). We did not find a significant increase in the 1‐OHP concentration in night urine specimens ( p = 0.19). Although the sample size was small, these findings indicate that urinary 1‐OHP may be a suitable biomarker of ETS carcinogen exposure in children.
No cholera epidemics have occurred in Taiwan since a severe outbreak caused by V. Cholerae serogroup O1 occurred in 1962 [1]. Although, during the period 1962-2009, several cholera infections have occurred, only a few are cluster infections and most of the reported cases are sporadic. The infection sources for most of the indigenous cholera infections occurred during the late twentieth century had been epidemiologically associated with the consumption of soft shelled turtle raised from contaminated farm ponds. However, the infection sources of indigenous cholera cases occurred during the recent five years were all unable to be identified. In order to understand the possible infection sources and relevant risk factors associated with cholera infections, we have reviewed epidemiologic investigation reports on indigenous cholera infection occurred during 1997~2009 and analyzed data from environmental surveillance in domestic areas, field investigation in foreign countries, and from relevant researches. The study found that all cholera infections occurred during the recent 12 years are sporadic except two cluster infections; elderly people and those with underlying disease, such as gastrectomy and chronic diseases, are population susceptible to cholera infection; and poor personal hygiene practices and food sanitation are important risk factors to cholera infections. The reasons why infection sources for most of the cholera cases could not be identified are partly because the recognition of infection sources for sporadic case has always been difficult and the insufficient information on food consumption during the incubation period of disease provided by patients. If physicians could keep vigilance and sensitivity over diagnosis of suspected cholera cases and promote notification efficiency, it would be useful for investigation of infection sources. Experiences from developed countries showed that the strains of toxigenic V. cholerae exist in natural environments, usually spread through the contamination of food, and cause infection in immuno-compromised hosts [2]. The study recommends that: 1. Local governments with cases occurred should strengthen health education directed at the susceptible population and the education of physicians on diagnosis and notification of suspected cases. 2. Investigators should do their best to collect detail information on food origin, food preparation, eating utensil, food storage, and eating habits of the reported cases, and health status of close contacts and neighborhood people. 3. National laboratory should establish data bank for native strains to facilitate the comparative analysis with strains from other countries. 4. Agriculture authority periodically conduct survey on environment and fishery of farm ponds; food sanitation authority routinely monitor on safety of marketed marine product; and authorities in charge of agriculture, food sanitation, and disease control should establish a channel for mutual communication and work together to assure citizen’s health and safety. 5. Department of disease control will have to collect and obtain information on environmental surveillance and risk assessment for coastal areas along Taiwan, Penghu, Kinmen, and Matzu.
We propose a new design of the polarization beam splitter based on photonic crystals at the wavelength 1.55µm. The numerical results show that the transmission efficiency is up to 91%.
The population of the Tibetan Antelope (Pantholops hodgsonii) has recently declined dramatically due to the illegal trade in its wool. The animal lives at high altitude and is protected from the extremely cold climate due to a coat of very fine wool. These hairs are highly sought for weaving a shawl called shahtoosh. The large-scale poaching of the antelope has resulted in the species being placed on CITES Appendix I. We report on a method of DNA profiling on a confiscated shahtoosh using the cytochrome b (cyt b) gene to produce a test that will identify unambiguously the presence of P. hodgsonii. Two shahtoosh samples were provided by the Council of Agriculture, Taiwan, and ten shawl samples of sheep wool (Ovis aries), cashmere from the Kashmir goat (Capra hircus), and pashmina from the Himalayan goat (C. hircus) were collected from local stores for comparison. Two primer pairs were used to amplify a 271 bp fragment of cyt b gene which would distinguish these three species. The resulting amplification products were directly sequenced. When the DNA sequences were compared with the sequences registered in GenBank and EMBL databases, the sequences with the highest homology were the cyt b genes of P. hodgsonii, C. hircus, and O. aries. This study demonstrates that there is still sufficient DNA present in the finished wool of a shahtoosh shawl to allow DNA typing and the method established was highly plausible to identify the CITES protected species.
＂Background＂: There are some morphological variants that may have a negative impact on the periodontal disease progression and treatment outcome. However, parts of these variants were found with racial predilection. The purpose of this study was to investigate the prevalence and anatomic characteristic of the distolingual root in the mandibular molar area in Taiwanese population through computed tomography images. ＂Material and Methods＂: Subjects were patients receiving mandibular computed tomography between 2011 and 2013 at Chi-Mei medical center. Those with missing teeth on both sides or with prosthesis with were excluded. Total 261 patients with computed tomography images of the mandibular molar teeth were included in the study. With 3-D image reconstruction software, the prevalence of the distolingual root, the roots length and the root trunks length of bilateral mandibular molar were measured and analyzed. ＂Results＂: The prevalence rate of disto-lingual root was 13.96% for the mandibular first molar and 0.77% for the mandibular second molar; the prevalence rate in the first molar was significantly higher than that in the second molar (p＜0.0001). Concurrent incidence on both sides of the first molar accounted for 7.35%. The distal root trunk was significantly longer than buccal and lingual root trunks (p＜0.0001). The disto-buccal root was significantly longer than the disto-lingual root (p＜0.05). The distal furcation was closer to the lingual side (p＜0.05). ＂Conclusion＂: The prevalence rate of disto-lingual rootof the mandibular first molar was obviously higher in the Taiwan population than in other regions and it helped with the understanding of anatomic morphological variants. The importance should not be ignored in the clinical setting.
A new all-optical switch based on the local nonlinear metal-insulator-metal (MIM) plasmonic Mach-Zehnder interferometer (MZI) waveguides was proposed. We used the finite-difference time-domain (FDTD) method to simulate the proposed structure. The numerical show that the proposed local nonlinear MIM plasmonic MZI waveguide structure could really function as an all-optical switch.
Objectives Grape-seed procyanidins (GSPs) can inhibit cell proliferation and invasiveness in various human cancers. However, the effect of GSP on pancreatic carcinoma cells has not been investigated. Methods Pancreatic carcinoma cell lines MIA PaCa-2 and BxPC-3 treated with GSP were assessed for viability by trypan blue exclusion, for cell cycle distribution by flow cytometry, for increased apoptosis by annexin V labeling, for their adhesion and invasion potential by evaluating their ability to penetrate through a matrix gel–coated Boyden chamber, and for changes in the levels of proteins involved in cellular events by immunoblotting. Results Grape-seed procyanidin inhibited MIA PaCa-2 and BxPC-3 proliferation in a dose-dependent manner and induced G1-phase arrest of the cell cycle in BxPC-3 or mitochondria-mediated apoptosis in MIA PaCa-2. Grape-seed procyanidin also inhibited the adhesion and invasion potential of both cell lines in a dose-dependent manner, which are associated with the suppression of metalloproteases matrix metalloproteinase 9 or 2 (MMP-9 or -2) expression. Conclusions Grape-seed procyanidin inhibited the proliferation of pancreatic carcinoma cells by cell cycle blockage or apoptotic induction. The invasiveness was also suppressed by GSP through down-regulation of MMP-2 or MMP-9 in pancreatic carcinoma cells. Grape-seed procyanidin is a potential chemotherapeutic or preventive agent for pancreatic carcinoma.
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