A new method of using photo-electromotive force in detecting gas and controlling sensitivity is proposed. Photo-electromotive force on the heterojunction between porous silicon thin layer and crystalline silicon wafer depends on the concentration of ammonia in the measurement chamber. A porous silicon thin layer was formed by electrochemical etching on p-type silicon wafer. A gas and light transparent electrical contact was manufactured to this porous layer. Photo-EMF sensitivity corresponding to ammonia concentration in the range from 10 ppm to 1,000 ppm can be maximized by controlling the intensity of illumination light.

Connected and automated vehicles (CAVs) have recently attracted a great deal of attention. Various studies have been conducted to improve vehicle and traffic safety through vehicle to vehicle (V2V) communication. In the field of CAVs, lane change research is considered a very challenging subject. This paper presents a cooperative lane change protocol, considering the impact of V2V communication delay. When creating a path for a lane change in the local path planning module, V2V communication delay occurs. Each vehicle was represented, in our study, by an oriented bounding box (OBB) to determine the risk of collision. We set up a highway driving simulation environment and verified the improved protocol by implementing a longitudinal and lateral controller.

Background/AimsThe aims of this study were to evaluate the effect of antiviral therapy on serum total cholesterol (TC) levels and to investigate the factors related to serum TC changes in chronic hepatitis C (CHC) patients.MethodsA total of 94 CHC patients, the majority of whom were infected with genotype 1 or 2 and were receiving antiviral therapy, were consecutively enrolled. TC levels before treatment, at week 4, at the end of treatment (EOT), and at 24 weeks after the EOT were analyzed, along with factors related to pre- and post-treatment TC levels.ResultsPretreatment TC levels in the sustained virologic response (SVR) group (167±3.6 mg/dL) and the non-SVR group (158±8.3 mg/dL) were similar, and both decreased during antiviral therapy. The TC levels at 24 weeks after the EOT significantly increased in the SVR group (183±4.7 mg/dL), but not in the non-SVR group (160±7.1 mg/dL, p=0.044) after adjusting for the pretreatment TC levels. The grade of hepatic fibrosis, as measured by the METAVIR score or the aspartate aminotransferase-platelet ratio index (APRI), but not viral load (p=0.119), was an independent variable associated with the pretreatment TC levels (METAVIR score, p=0.011; APRI, p=0.033). After adjusting for the presence of a SVR by longitudinal data analysis using generalized estimating equations, the independent variable APRI was associated with the serum TC level after antiviral therapy (p=0.014), whereas a SVR was associated with the serum TC level only with marginal statistical significance (p=0.084).ConclusionsSerum TC levels increased in the SVR group after antiviral therapy for CHC; however, this was probably due to an improvement in liver fibrosis rather than the eradication of virus.

PurposeThere are still debates on the benefit of mass screening for prostate cancer (PCA) by prostate specific antigen (PSA) testing, and on systemized surveillance protocols according to PSA level. Furthermore, there is a paucity of literature on current practice patterns according to PSA level in the Korean urologic field. Here, we report the results of a nationwide, multicenter, retrospective chart-review study.Materials and MethodsOverall 2122 Korean men (>40 years old, PSA >2.5 ng/mL) were included in our study (from 122 centers, in 2008). The primary endpoint was to analyze the rate of prostate biopsy according to PSA level. Secondary aims were to analyze the detection rate of PCA, the clinical features of patients, and the status of surveillance for PCA according to PSA level.ResultsThe rate of prostate biopsy was 7.1%, 26.3%, 54.2%, and 64.3% according to PSA levels of 2.5-3.0, 3.0-4.0, 4.0-10.0, and >10.0 ng/mL, respectively, and the PCA detection rate was 16.0%, 22.2%, 20.2%, and 59.6%, respectively. At a PSA level >4.0 ng/mL, we found a lower incidence of prostate biopsy in local clinics than in general hospitals (21.6% vs. 66.2%, respectively). A significant proportion (16.6%) of patients exhibited high Gleason scores (≥8) even in the group with low PSA values (2.5-4.0 ng/mL).ConclusionWe believe that the results from this nationwide study might provide an important database for the establishment of practical guidelines for the screening and management of PCA in Korean populations.

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