Caregiving of children with intellectual disabilities in China--an examination of affiliate stigma and the cultural thesis.

BACKGROUND: While caregivers of children with intellectual disabilities are burdened in every part of the world, it is suspected that particular contexts may make the situation worse. There is little literature on caregivers in China, where familial and clan responsibility rather than individual effort is emphasised, and where communal support, while treasured, is often lacking. METHOD: A total of 211 caregivers in two cities, one with and the other without randomised design, participated in a survey study that assessed affiliated stigma, loss of face, anxiety, mental health and empowerment. RESULTS: A proportion of 60.6% of participants were found to be conspicuous cases with mental disturbance of a level which required further professional attention. Participants with better resource appeared to have coped better, enjoying lower psychological distress, lower anxiety and a higher level of personal empowerment. Multiple regression analysis revealed that mental health is related to the affective dimension of affiliated stigma, loss of face and anxiety level. This was found to account for more than half the variance (55%). DISCUSSION: The subjective burden of care occurs not in isolation but in a cultural field. Chinese caregiving is characterised by a lack of formal support, and such cultural concerns as loss of face and strong affiliated stigma. This socio-political context makes caregiving all the more challenging. The situation has to be addressed by both practitioners and policy makers if family caregiving is to be valued and made sustainable.

Improved optical transmission and current matching of a triple-junction solar cell utilizing sub-wavelength structures.

Sub-wavelength antireflective structures are fabricated on a silicon nitride passivation layer of a Ga0.5In0.5P/GaAs/Ge triple-junction solar cell using polystyrene nanosphere lithography followed by anisotropic etching. The fabricated structures enhance optical transmission in the ultraviolet wavelength range, compared to a conventional single-layer antireflective coating (ARC). The transmission improvement contributes to an enhanced photocurrent, which is also verified by the external quantum efficiency characterization of the fabricated solar cells. Under one-sun illumination, the short-circuit current of a cell with sub-wavelength structures is enhanced by 46.1% and 3.4% due to much improved optical transmission and current matching, compared to cells without an ARC and with a conventional SiN(x) ARC, respectively. Further optimizations of the sub-wavelength structures including the periodicity and etching depth are conducted by performing comprehensive calculations based on a rigorous couple-wave analysis method.

Squamous cell carcinoma arising from an epidermal cyst.

There are few case reports in the English literature concerning malignant transformation of an epidermal cyst into squamous cell carcinoma. We report a case of squamous cell carcinoma arising from a 40-year epidermal cyst in the proximal left thigh of a 74-year-old man. The epidermal cyst had increased in size in the previous 3 years. The patient presented with a discharge from the lesion. Ultrasonography and magnetic resonance imaging of the lesion suggested malignancy. An intra-operative frozen section of an incisional biopsy of the lesion found it to be an epidermal cyst with suspected malignant change, so a marginal excision of the lesion was performed. Squamous cell carcinoma arising from the epidermal cyst was confirmed histologically. A wide excision was done in order to obtain an adequate resection margin. A computed tomographic scan of the thorax and abdomen found no evidence of metastases. No evidence of recurrence was noted in the latest follow-up, 2 years postoperatively.

Volatile organic compounds (VOCs) in urban atmosphere of Hong Kong.

The assessment of volatile organic compounds (VOCs) has become a major issue of air quality network monitoring in Hong Kong. This study is aimed to identify, quantify and characterize volatile organic compounds (VOCs) in different urban areas in Hong Kong. The spatial distribution, temporal variation as well as correlations of VOCs at five roadside sampling sites were discussed. Twelve VOCs were routinely detected in urban areas (Mong Kok, Kwai Chung, Yuen Long and Causeway Bay). The concentrations of VOCs ranged from undetectable to 1396 microg/m3. Among all of the VOC species, toluene has the highest concentration. Benzene, toluene, ethylbenzene and xylenes (BTEX) were the major constituents (more than 60% in composition of total VOC detected), mainly contributed from mobile sources. Similar to other Asian cities, the VOC levels measured in urban areas in Hong Kong were affected both by automobile exhaust and industrial emissions. High toluene to benzene ratios (average T/B ratio = 5) was also found in Hong Kong as in other Asian cities. In general, VOC concentrations in the winter were higher than those measured in the summer (winter to summer ratio > 1). As toluene and benzene were the major pollutants from vehicle exhausts, there is a necessity to tighten automobile emission standards in Hong Kong.

Drug-induced acute interstitial nephritis in renal allografts: histopathologic features and clinical course in six patients.

Drug-induced acute interstitial nephritis is a common cause of dysfunction in native kidneys, but is rarely reported in renal allografts. This report describes six renal transplant recipients with acute renal allograft dysfunction or delayed allograft function in whom a renal transplant biopsy showed histopathologic features of drug-induced interstitial nephritis with no diagnostic evidence of acute rejection, cyclosporine or tacrolimus nephrotoxicity, or other lesion that could account for the graft dysfunction. In five of the six patients, interstitial nephritis occurred within 4 weeks of transplantation. All the patients were receiving trimethaprim-sulfamethoxazole and/or other drugs associated with interstitial nephritis. After discontinuation of these drugs and short-term corticosteroid treatment, all patients showed improvement in renal function, although the time course of this improvement varied considerably, with three patients showing a return to baseline serum creatinine level within 2 weeks and two patients showing a gradual improvement over 8 weeks. Four of the five patients followed up for more than 1 year (range, 14 to 33 months) after the episode of interstitial nephritis had good allograft function (serum creatinine level

Analysis of fracture prevalence in kidney-pancreas allograft recipients.

Fractures occur in 11 to 26% of renal allograft recipients after transplantation despite improvements in bone and mineral disorders. This high fracture rate is likely a consequence of accelerated osteopenia. The cause of posttransplant bone loss is multifactorial, and patients with insulin-dependent diabetes mellitus and renal failure may have additional fracture risks such as low turnover bone disease. This retrospective cohort study was undertaken to determine the long-term incidence and the potential risk factors of posttransplant fractures in patients with insulin-dependent diabetes mellitus undergoing combined kidney-pancreas allograft transplantation. Thirty-five patients with insulin-dependent diabetes mellitus who received a combined kidney-pancreas allograft between 1987 and 1992 were evaluated. Thirty-five kidney allograft recipients matched for age, gender, and the date of transplant were also reviewed. The fracture incidence in the kidney-pancreas group was 49% after transplantation. The rate of first fracture after kidney-pancreas transplantation was 12.1% per patient year, resulting in a 5-yr fracture-free rate of 48%. The initial fracture occurred at a mean of 31.06 +/- 19.9 mo. Steroid exposure was found to increase the risk of fracture, and analysis by means of a Cox regression model estimated that an increase in cumulative steroid exposure of 10 mg/kg at any given month increased the hazard of sustaining a fracture by 9% (95% confidence interval for hazard ratio, 1.01 to 1.18; P = 0.031). This analysis suggests that kidney-pancreas recipients are at significant risk of sustaining a fracture within a few years after transplantation.

Learning-based ventricle detection from cardiac MR and CT images.

The objective of this work is to investigate the issue of automatically detecting regions of interest (ROI's) in medical images. It is assumed that the regions to be detected can be roughly segmented by a threshold based on a likelihood measure of the ROI. First, an analysis of the global histogram is used to compute a preliminary threshold that is likely near the optimal one. The histogram analysis is motivated by the analytical result of a bell image intensity model proposed in this work. Then, the preliminary threshold is used to segment the input image, resulting in an attention map, which contains an attention region that approximates the ROI as well as many spurious ones. Due to the nonoptimality of the preliminary threshold, it can happen that the attention region contains a part of, or more regions than, the ROI. Learning takes place in two stages: 1) learning for automatic selection of the preliminary threshold value and 2) learning for automatically selecting the ROI from the attention map while dynamically tuning the threshold according to the learned-likelihood function. Experiments have been conducted to approximately locate the endocardium boundaries of the left and right ventricles from gradient-echo magnetic resonance (MR) images. Cardiac computed tomography (CT) images have also been used for testing. The boundary of the segmented region provided by this algorithm is not very accurate and is meant to be used for further fine tuning based on other application-specific measures.

The x-ray fovea, a device for reducing x-ray dose in fluoroscopy.

The x-ray fovea (U.S. patents pending) is a device for reducing x-ray dose to patients and operations during x-ray fluoroscopy. It consists of a semitransparent collimator with an open, circular, central hole. The fovea collimator is placed at the exit of the x-ray tube, and the attenuation of the peripheral x-ray beam reduces x-ray exposure to patients and operators. The shadow caused by the x-ray fovea can be compensated using real-time image processing hardware. Accurate compensation is demonstrated for both linearly and logarithmically acquired images using a model that accounts for beam hardening in the fovea collimator. The central fovea region has improved image quality due to reduced scatter and veiling glare from the periphery. From beam-stop measurements, a 40% reduction in scatter plus veiling glare is measured using the fovea. A contrast improvement ratio of 1.5 is measured throughout the central region. In the compensated periphery, noise is increased by a factor of 1.66 because fewer photons are detected, but a small amount of temporal filtering compensates this degradation. The Roentgen area product (RAP) exposure to patients is reduced by approximately 70%, while scattered exposure to operators is reduced by approximately 60%.

Imaging with rotating slit apertures and rotating collimators.

The statistical quality of conventional nuclear medical imagery is limited by the small signal collected through low-efficiency conventional apertures. Coded-aperture imaging overcomes this by employing a two-step process in which the object is first efficiently detected as an "encoded" form which does not resemble the object, and then filtered (or "decoded") to form an image. We present here the imaging properties of a class of time-modulated coded apertures which, unlike most coded apertures, encode projections of the object rather than the object itself. These coded apertures can reconstruct a volume object nontomographically, tomographically (one plane focused), or three-dimensionally. We describe a new decoding algorithm that reconstructs the object from its planar projections. Results of noise calculations are given, and the noise performance of these coded-aperture systems is compared to that of conventional counterparts. A hybrid slit-pinhole system which combines the imaging advantages of a rotating slit and a pinhole is described. A new scintillation detector which accurately measures the position of an event in one dimension only is presented, and its use in our coded-aperture system is outlined. Finally, results of imaging test objects and animals are given.

Use of an image orthicon as an array of lock-in amplifiers.

If the accelerating voltage is modulated, an image orthicon TV camera can be operated as a synchronous, bipolar image detector. Experimental verification of this mode of operation is presented.

Optical transfer function synthesis: a geometrical optics approach.

It is shown that, within the limits of geometrical optics, it is possible to specify a pure-phase pupil function that will produce any desired optical transfer function (OTF) or point spread function (PSF) in an incoherent optical processing system. A general prescription for finding the pupil function is presented, and specific analytical results are given for simple power-law PSFs. As an example, the fabrication and testing of a logarithmic phase plate that produces an appropriate PSF for incoherent optical processing of transaxial tomography data are discussed.