Investigation on Performance of a Converted Remote Sensing System for Diesel Tailpope Emissions Monitoring

Roadside remote sensing (RS) has been adopted by the environmental protection department of Hong Kong as a tool for controlling urban air quality issues induced by on-road vehicles. The technology provides the unique advantage of being able to scan a large number of vehicles without interfering the traffic. The horizontal or cross-road RS (HRS) devices in used today are mostly tailored for single-lane applications. where the path of the RS light beam is parallel to the road surface, and emission scanning are limited to some segments of the roadway network. Vertical remote sensing (VRS) that scans an exhaust plume with a light beam perpendicular to the road surface has been proposed for multiple-lane applications but published results are scarce. VRS offers the advantage of being able to distinguish the plumes of different vehicles [1] but comes with some snags associated with installation, protection, and maintenance of the ground unit. A diagonal remote sensing (DRS) system is a modified version of the conventional RS with the light source and the detector unit (the main unit) lifted and tilted to scan the exhaust plume of a passing car diagonally and the ground unit titled to deflect the light back to the main unit. Such setup could prevent the ground unit being drove over and, therefore, reduce the needs to protect and maintain the ground unit. Plume dispersion models of box trailer trucks revealed that an area of recirculation appear at the close vicinity of the back of the trucks [2, 3]. The tilt angle of the DRS could be adjusted to scan the recirculation pockets of different types of vehicle. This study aims at evaluating the performance of a DRS prototype system that was converted from conventional RS devices in detecting exhaust emissions from a diesel truck, comparing the performance of DRS to those of HRS and VRS, and determining the feasibility of deploying DRS in single-lane applications. The RS systems measured the tailpipe emissions from a designated diesel vehicle equipped with portable emission measurement systems (PEMS) under a range of loading and driving conditions (i.e., 0 — 50% load and 10 — 30 km/h). The average NOx to CO2 ratio recorded by the HRS, VRS, and DRS systems were 44% (+ 6%), 32% (+ 4.5%), and 36% (+ 5.7%) of the PEMS equivalent measurements, respectively. The linear regression analyses of the HRS-PEMS pair, VRS-PEMS pair, and DRS-PEMS pair in terms of NOx/CO2 revealed that the correlation between HRS-PEMS is the most significant followed by VRS and DRS. The average NOx signal magnitude of the HRS, VRS, and DRS systems were 0.52, 0.61, and 0.21, respectively. It is concluded that the performance of the proposed DRS system is comparable to the performances of the HRS and VRS systems and DRS could be an opportunity to expand the role of RS in urban air quality control. ‘The work described in this study was fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. UGC/IDS(c)25/E02/19)

Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke

<p>Abstract</p> <p>Background</p> <p>Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH), a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims to investigate the potential mechanisms of the preventive effects of Pien Tze Huang on brain damage caused by chronic ischemia and hypertensive stroke in rats.</p> <p>Methods</p> <p>The effects of Pien Tze Huang on brain protein expression in spontaneously hypertensive rat (SHR) and stroke prone SHR (SHRsp) were studied with 2-D gel electrophoresis and mass spectrometric analysis with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)/TOF tandem mass spectrometer and on brain cell death with enzyme link immunosorbent assay (ELISA) and immunostaining.</p> <p>Results</p> <p>Pien Tze Huang decreased cell death in hippocampus and cerebellum caused by chronic ischemia and hypertensive stroke. Immunostaining of caspase-3 results indicated that Pien Tze Huang prevents brain cells from apoptosis caused by ischemia. Brain protein expression results suggested that Pien Tze Huang downregulated QCR₂in the electron transfer chain of mitochondria preventing reactive oxygen species (ROS) damage and possibly subsequent cell death (caspase 3 assay) as caused by chronic ischemia or hypertensive stroke to hippocampus and cerebellum.</p> <p>Conclusion</p> <p>Pien Tze Huang showed preventive effects on limiting the damage or injury caused by chronic ischemia and hypertensive stroke in rats. The effect of Pien Tze Huang was possibly related to prevention of cell death from apoptosis or ROS/oxidative damage in mitochondria.</p

Mindfulness-based cognitive therapy v. group psychoeducation for people with generalised anxiety disorder: randomised controlled trial

Background: Research suggests that an 8-week mindfulness-based cognitive therapy (MBCT) course may be effective for generalised anxiety disorder (GAD). Aims: To compare changes in anxiety levels among participants with GAD randomly assigned to MBCT, cognitive–behavioural therapy-based psychoeducation and usual care. Method: In total, 182 participants with GAD were recruited (trial registration number: CUHK_CCT00267) and assigned to the three groups and followed for 5 months after baseline assessment with the two intervention groups followed for an additional 6 months. Primary outcomes were anxiety and worry levels. Results: Linear mixed models demonstrated significant group × time interaction (F(4,148) = 5.10, P = 0.001) effects for decreased anxiety for both the intervention groups relative to usual care. Significant group × time interaction effects were observed for worry and depressive symptoms and mental health-related quality of life for the psychoeducation group only. Conclusions: These results suggest that both of the interventions appear to be superior to usual care for the reduction of anxiety symptoms

Moment-To-moment affective dynamics in schizophrenia and bipolar disorder

Background: Affective disturbances in schizophrenia and bipolar disorder may represent a transdiagnostic etiological process as well as a target of intervention. Hypotheses on similarities and differences in various parameters of affective dynamics (intensity, successive/acute changes, variability, and reactivity to stress) between the two disorders were tested.Methods: Experience sampling method was used to assess dynamics of positive and negative affect, 10 times a day over 6 consecutive days. Patients with schizophrenia (n = 46) and patients with bipolar disorder (n = 46) were compared against age-matched healthy controls (n = 46).Results: Compared to controls, the schizophrenia group had significantly more intense momentary negative affect, a lower likelihood of acute changes in positive affect, and reduced within-person variability of positive affect. The bipolar disorder group was not significantly different from either the schizophrenia group or the healthy control group on any affect indexes. Within the schizophrenia group, level of depression was associated with weaker reactivity to stress for negative affect. Within the bipolar disorder group, level of depression was associated with lower positive affect.Conclusions: Patients with schizophrenia endured a more stable and negative affective state than healthy individuals, and were less likely to be uplifted in response to happenings in daily life. There is little evidence that these affective constructs characterize the psychopathology of bipolar disorder; such investigation may have been limited by the heterogeneity within group. Our findings supported the clinical importance of assessing multiple facets of affective dynamics beyond the mean levels of intensity.</p

A novel Hsp90 inhibitor AT13387 induces senescence in EBV-positive nasopharyngeal carcinoma cells and suppresses tumor formation

Background: Nasopharyngeal carcinoma (NPC) is an epithelial malignancy strongly associated with Epstein-Barr virus (EBV). AT13387 is a novel heat shock protein 90 (Hsp90) inhibitor, which inhibits the chaperone function of Hsp90 and reduces expression of Hsp90-dependent client oncoproteins. This study aimed to evaluate both the in vitro and in vivo antitumor effects of AT13387 in the EBV-positive NPC cell line C666-1.Results: Our results showed that AT13387 inhibited C666-1 cell growth and induced cellular senescence with the downregulation of multiple Hsp90 client oncoproteins EGFR, AKT, CDK4, and restored the protein expression of negative cell cycle regulator p27. We also studied the ability of AT13387 to restore p27 expression by downregulation of AKT and the p27 ubiquitin mediator, Skp2, using AKT inhibitor and Skp2 siRNA. In the functional study, AT13387 inhibited cell migration with downregulation of a cell migration regulator, HDAC6, and increased the acetylation and stabilization of α-tubulin. We also examined the effect of AT13387 on putative cancer stem cells (CSC) by 3-D tumor sphere formation assay. AT13387 effectively reduced both the number and size of C666-1 tumor spheres with decreased expression of NPC CSC-like markers CD44 and SOX2. In the in vivo study, AT13387 significantly suppressed tumor formation in C666-1 NPC xenografts.Conclusion: AT13387 suppressed cell growth, cell migration, tumor sphere formation and induced cellular senescence on EBV-positive NPC cell line C666-1. Also, the antitumor effect of AT13387 was demonstrated in an in vivo model. This study provided experimental evidence for the preclinical value of using AT13387 as an effective antitumor agent in treatment of NPC. © 2013 Chan et al.; licensee BioMed Central Ltd.published_or_final_versio