3,153 research outputs found
2-[(5,7-DibromoÂquinolin-8-yl)Âoxy]-N-(2-methÂoxyÂphenÂyl)acetamide
In the title compound, C18H14Br2N2O3, an intraÂmolecular N—H⋯N hydrogen bond forms an eight-membered ring. The dihedral angle between the planes of the quinoline system and the benzene ring is 41.69 (1)°. The crystal packing is stabilized by interÂmolecular C—H⋯O hydrogen bonds and short Br⋯O interÂactions [3.0079 (19) Å]
Automatic fall incident detection in compressed video for intelligent homecare
[[abstract]]This paper presents a compressed-domain fall incident detection scheme for intelligent homecare applications. First, a compressed-domain object segmentation scheme is performed to extract moving objects based on global motion estimation and local motion clustering. After detecting the moving objects, three compressed-domain features of each object are then extracted for identifying and locating fall incidents. The proposed system can differentiate fall-down from squatting by taking into account the event duration. Our experiments show that the proposed method can correctly detect fall incidents in real time.[[fileno]]2030144030047[[department]]電機工程å¸
Predictors of continued HIV-risk behaviors among drug users in methadone maintenance therapy program in China—A prospective study
BACKGROUND: To examine the predictors of continued drug- and sex-related HIV-risk behaviors among drug users in methadone maintenance therapy (MMT) programs in China. METHODS: We followed a sample of 5,035 drug users enrolled for the first time in MMT programs at baseline, 6 months, and 12 months utilizing a longitudinal prospective study design. Drug users’ HIV-risk behaviors, MMT characteristics, and drug use, were assessed at all three waves using a structured interview and HIV/HCV status was assessed at baseline and 12-month follow-up using biological specimens. RESULTS: The point prevalence of HIV was 7.6% and 78.4% for HCV at baseline. Results of generalized linear mixed logistic regression models revealed that HIV-positive MMT clients were more likely to engage in drug injection (aOR = 1.70) and syringe sharing (aOR = 4.73). HCV-positive clients were more likely to inject drugs (aOR = 2.58), share syringes (aOR = 1.97), and have multiple sexual partners (aOR = 1.47). Adherence to MMT was the most significant predictor of reduced HIV-risk behaviors. CONCLUSIONS: Our data confirmed the positive effects of MMT on HIV prevention and underscored the urgency for programs to reduce HIV risk in HIV- and HCV-positive clients. There is a pressing need to strengthen existing counseling services for HIV-positive drug users to reduce their drug-related risk behaviors and to provide counseling for HCV-positive drug users. Further studies are needed to explore interventions to address high dropout rates and low adherence among MMT clients
Binding of PFOS to serum albumin and DNA: insight into the molecular toxicity of perfluorochemicals
<p>Abstract</p> <p>Background</p> <p>Health risk from exposure of perfluorochemicals (PFCs) to wildlife and human has been a subject of great interest for understanding their molecular mechanism of toxicity. Although much work has been done, the toxigenicity of PFCs remains largely unknown. In this work, the non-covalent interactions between perfluorooctane sulfonate (PFOS) and serum albumin (SA) and DNA were investigated under normal physiological conditions, aiming to elucidate the toxigenicity of PFCs.</p> <p>Results</p> <p>In equilibrium dialysis assay, the bindings of PFOS to SA correspond to the Langmuir isothermal model with two-step sequence model. The saturation binding number of PFOS was 45 per molecule of SA and 1 per three base-pairs of DNA, respectively. ITC results showed that all the interactions were spontaneous driven by entropy change. Static quenching of the fluorescence of SA was observed when interacting with PFOS, indicating PFOS bound Trp residue of SA. CD spectra of SA and DNA changed obviously in the presence of PFOS. At normal physiological conditions, 1.2 mmol/l PFOS reduces the binding ratio of Vitamin B<sub>2 </sub>to SA by more than 30%.</p> <p>Conclusion</p> <p>The ion bond, van der Waals force and hydrophobic interaction contributed to PFOS binding to peptide chain of SA and to the groove bases of DNA duplex. The non-covalent interactions of PFOS with SA and DNA alter their secondary conformations, with the physiological function of SA to transport Vitamin B<sub>2 </sub>being inhibited consequently. This work provides a useful experimental method for further studying the toxigenicity of PFCs.</p
Key predisposing factors and susceptibility assessment of landslides along the Yunnan–Tibet traffic corridor, Tibetan plateau: Comparison with the LR, RF, NB, and MLP techniques
The Yunnan–Tibet traffic corridor runs through the Three Rivers Region, southeastern Tibetan Plateau, which is characterized by high-relief topography and active tectonics, with favourable conditions for landslides. It is of great significance to identify the key predisposing factors of landslides and to reveal the landslide susceptibility in this area. A total of 2,308 landslides were identified as learning samples through remote sensing interpretation and detailed field surveys, and four machine learning algorithms involving logistic regression (LR), random forest (RF), naïve Bayes (NB) and multilayer perceptron (MLP) were compared to model the landslide susceptibility. Through the multicollinearity test, 13 influential factors were selected as conditioning factors. The area under the curve (AUC) values of LR, RF, NB and MLP models are .788, .918, .785 and .836 respectively, indicating that the four models have good or very good prediction accuracy in landslide susceptibility assessment along the Yunnan–Tibet traffic corridor. In addition, the elevation, slope, rainfall, distance to rivers, and aspect play a major role in landslide development in the study area. The susceptibility zoning map based on the best RF model shows that the areas with high susceptibility and very high susceptibility account for 12.24% and 6.72%, respectively, and are mainly distributed along the Jinsha River, the Lancang River and the G214 highway
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