Minimization of current stress on the grid synchronization of doubly-fed induction generators for wind power generation

Author name used in this publication: S. L. HoAuthor name used in this publication: K. W. E. ChengVersion of RecordPublishe

Differential effects of anti-B7-1 and anti-B7-2 monoclonal antibody treatment on the development of diabetes in the nonobese diabetic mouse.

Insulin-dependent diabetes mellitus (IDDM) is thought to be an immunologically mediated disease resulting in the complete destruction of the insulin-producing islets of Langerhans. It has become increasingly clear that autoreactive T cells play a major role in the development and progression of this disease. In this study, we examined the role of the CD28/B7 costimulation pathway in the development and progression of autoimmune diabetes in the nonobese diabetic (NOD) mouse model. Female NOD mice treated at the onset of insulitis (2-4 wk of age) with CTLA4Ig immunoglobulin (Ig) (a soluble CD28 antagonist) or a monoclonal antibody (mAb) specific for B7-2 (a CD28 ligand) did not develop diabetes. However, neither of these treatments altered the disease process when administered late, at > 10 wk of age. Histological examination of islets from the various treatment groups showed that while CTLA4Ig and anti-B7-2 mAb treatment blocked the development of diabetes, these reagents had little effect on the development or severity of insulitis. Together these results suggest that blockade of costimulatory signals by CTLA4Ig or anti-B7-2 acts early in disease development, after insulitis but before the onset of frank diabetes. NOD mice were also treated with mAbs to another CD28 ligand, B7-1. In contrast to the previous results, the anti-B7-1 treatment significantly accelerated the development of disease in female mice and, most interestingly, induced diabetes in normally resistant male mice. A combination of anti-B7-1 and anti-B7-2 mAbs also resulted in an accelerated onset of diabetes, similar to that observed with anti-B7-1 mAb treatment alone, suggesting that anti-B7-1 mAb's effect was dominant. Furthermore, treatment with anti-B7-1 mAbs resulted in a more rapid and severe infiltrate. Finally, T cells isolated from the pancreas of these anti-B7-1-treated animals exhibited a more activated phenotype than T cells isolated from any of the other treatment groups. These studies demonstrate that costimulatory signals play an important role in the autoimmune process, and that different members of the B7 family have distinct regulatory functions during the development of autoimmune diabetes

A survey of chronic rhinitis in Hong Kong

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香港977位慢性鼻炎患者的過敏原皮膚點刺測試結果

OBJECTIVES: To evaluate the prevalence of aetiological allergens identifiable by skin prick test alone in patients suffering from chronic rhinitis in Hong Kong, and also compare the clinical history and symptoms of skin prick test-positive versus skin prick test-negative patients. DESIGN: Prospective study. SETTING: Otorhinolaryngology clinic in Queen Mary Hospital of Hong Kong. PATIENTS: A total of 977 patients suffering from chronic rhinitis were recruited into the study. Skin prick test was performed with a panel of allergens including house dust mites, cockroach, cat, dog, moulds, and pollens. MAIN OUTCOME MEASURES: Skin prick test results and their correlation with symptoms. RESULTS: Of the 977 patients, 651 (67%) had positive skin prick test reactions. The commonest allergen was house dust mite which was positive in 63% of the 977 patients and 95% of those 651 skin prick test-positive patients. The other allergens were in order of cockroach (23%), cat (14%), dog (5%), pollen (4%), and mould (3%). Compared with skin prick test-negative patients, skin prick test-positive patients were more likely to have earlier age of onset of the chronic rhinitis, association with asthma, more severe symptom in the morning, more severe symptoms of itchy nose, sneezing, nasal discharge, itchy eye, and watery eye. CONCLUSIONS: Identifiable aeroallergens could be detected in 67% chronic rhinitis patients by skin prick test alone. House dust mites were the most prevalent causative allergen. There were significant differences of patterns of clinical history and symptoms severity between skin prick test-positive and skin prick test-negative patients.published_or_final_versio

The effect of SARS on the price of re-entrants in multi-storey apartment buildings

Natural lighting and ventilation have long been a primary consideration in building design, particularly for those high-rise and densely packed apartment blocks where mechanical ventilation is normally secondary. In Hong Kong, there are prescriptive legal requirements governing the provision of natural lighting and ventilation in private buildings. This, coupled with developers’ profit-maximizing incentives, often gives rise to re-entrant designs commonly found in apartment buildings in Hong Kong. This paper aims to study the economic impacts of the disposition of re-entrants on property prices with reference to the revelation of the chimney effect of re-entrants after the occurrence of the mass community outbreak of Severe Acute Respiratory Disease (SARS) in Amoy Gardens in 2003. In this study, we use a hedonic pricing model to examine whether flats designed with a re-entrant is sold at a different price than those without a re-entrant. We draw a sample of property transactions from a popular single residential development with variations in re-entrant designs. A total of 357 transactions were collected, of which 90 were transacted after the SARS event. The model is capable to monitor any significance changes in the premium of re-entrant and its relationship with floor level before and after SARS. Based on the hedonic pricing analysis, we found that the preference for re-entrants is floor-dependent. Before SARS, homebuyers were not fond of re-entrants on low floor levels, but they were willing to pay more for re-entrants as the floor level increases. Yet, the outbreak of SARS did not significantly change their preferences for re-entrants. The market is capable to capitalize the building design into property prices. Developers and designs should improve their building design to meet the ever changing needs of the market. This paper provides an empirical framework to examine how homebuyers price a particular design feature using property transaction data.published_or_final_versio

An empirical study on the neighbourhood effect of refurbishment

An important portion of property value comes from property location, which is a function of the quality of surrounding environment (e.g. external views). In a congested living environment like Hong Kong, it is difficult, if not impossible, to have a view unobstructed by buildings. As such, the quality of views is dependent upon the aesthetic quality of surrounding buildings. It is likely that poorly maintained buildings will emit negative visual effects to their immediate neighbourhood. Refurbishing these poor buildings should, therefore, reduce or even counter this negative externality. This study aims to empirically identify the effect of refurbishment on the prices of neighbourhood properties based on an analysis of panel data in Hong Kong. The data consists of property transactions in a large housing estate located in Pokfulam. This estate was chosen because its surrounding buildings underwent refurbishment in 1998. Results show that the refurbishment brought a significant increase in the price of properties facing the refurbished buildings, keeping other things constant. Given the aging building problem in most urban areas, the results pose significant practical implications on building refurbishment and urban rehabilitation as a whole. Developers or property owners may be lured to invest in the refurbishment of adjacent dilapidated properties with a view to a value enhancement of their own properties.published_or_final_versio

Functional antioxidant and tyrosinase inhibitory properties of extracts of Taiwanese pummelo (Citrus grandis Osbeck)

In recent years, the overproduction of citrus fruits has resulted in an unnecessary increase in agricultural wastes in Taiwan. In an attempt to find an application for these potentially valuable wastes, we evaluated the antioxidant and whitening properties of six Taiwanese pummelo varieties (Miyu Shihtouyu Taipeiyu Touyu Wentan and Hsishihyu). The methanolic extract of Citrus grandis Osbeck Miyu (Miyu) had the highest phenolic content (9.99 mg of gallic acid equivalent/g). C. grandis Osbeck Shihtouyu (Shihtouyu) displayed the highest 2, 2-azino-bis-(3- ethylbenzthiazoline-6-sulfonic acid) content (9.3 mg trolox equivalent antioxidant content/g), indicating its good free radical-scavenging activity. C. grandis Osbeck Taipeiyu (Taipeiyu) showed the highest 1,1-diphenyl-2-picrylhydrazyl content and this compound too possesses good radical-scavenging activity. The ferrous-ion chelating effect of C. grandis Osbeck Touyu (Touyu) and C. grandis Osbeck Wentan (Wentan) was found to be 0.78 and 0.92 mg/ml, respectively. Taipeiyu showed the highest limonin content (1251.86 μg/ml). Touyu inhibited tyrosinase up to 90.8% (10 mg/ml), which was almost similar to the 95% inhibition shown by kojic acid (10 mg/ml). Thus, the components of pummelo have high potential for use as ingredients in products that prevent skin pigmentation. These results indicate that the methanolic extracts and the phytochemicals derived from pummelo are potential natural antioxidant agents.Key words: Antioxidant, free radical chelating, limonin, pummelo, tyrosinase

Initial results of selective renal parenchymal clamping with an adjustable kidney clamp in nephron-sparing surgery: an easy way to minimise renal ischaemia

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Structural and Functional Brain Remodeling during Pregnancy with Diffusion Tensor MRI and Resting-State Functional MRI

Although pregnancy-induced hormonal changes have been shown to alter the brain at the neuronal level, the exact effects of pregnancy on brain at the tissue level remain unclear. In this study, diffusion tensor imaging (DTI) and resting-state functional MRI (rsfMRI) were employed to investigate and document the effects of pregnancy on the structure and function of the brain tissues. Fifteen Sprague-Dawley female rats were longitudinally studied at three days before mating (baseline) and seventeen days after mating (G17). G17 is equivalent to the early stage of the third trimester in humans. Seven age-matched nulliparous female rats served as non-pregnant controls and were scanned at the same time-points. For DTI, diffusivity was found to generally increase in the whole brain during pregnancy, indicating structural changes at microscopic levels that facilitated water molecular movement. Regionally, mean diffusivity increased more pronouncedly in the dorsal hippocampus while fractional anisotropy in the dorsal dentate gyrus increased significantly during pregnancy. For rsfMRI, bilateral functional connectivity in the hippocampus increased significantly during pregnancy. Moreover, fractional anisotropy increase in the dentate gyrus appeared to correlate with the bilateral functional connectivity increase in the hippocampus. These findings revealed tissue structural modifications in the whole brain during pregnancy, and that the hippocampus was structurally and functionally remodeled in a more marked manner.published_or_final_versio

Prune belly syndrome – Case report and review of the literature

We describe a 2-year-old boy seen in Kenya who presented with fever, dysuria, foul smelling urine, anddiarrhea. His previous ultrasonography showed an overdistended bladder and hydronephrosis. Physicalexamination revealed a distended abdomen, loose abdominal wall muscles with thin, flabby, and wrinkledskin on the abdominal wall, hypoplastic scrotum, and bilateral cryptorchidism. A diagnosis of prune bellysyndrome was promptly made. The urinary tract infection was duly treated with intravenous ceftriaxoneand the child followed by pediatric urology