A gamma ray spectrometer with Compton suppression on the HL-2A tokamak.

A new broad-energy, high-resolution gamma ray spectrometer (GRS) with Compton suppression function has been developed recently in the HL-2A tokamak to obtain the gamma ray information in the energy range of 0.1-10 MeV. This is the first time to develop an anti-Compton GRS for a magnetic confinement fusion device. The anticoincidence detector consists of a large-volume high purity germanium (HPGe) crystal (Φ63 × 63 mm2) as the primary detector and eight trapezoidal bismuth germinate (BGO) scintillators (trapezoid crystal with 30 mm thickness) as the secondary detector. The anti-coincidence data processing is implemented by a digital-based data acquisition system with fast digitization and software signal processing technology. Using radioisotope gamma ray sources and Monte Carlo N-Particle code, the energy and efficiency of the spectrometer have been calibrated and quantitatively tested. The Compton continuum suppression factor reaches 4.2, and the energy resolution (Full Width at Half Maximum) of the 1.332 MeV full energy peak for 60Co is 2.1 keV. Measurements of gamma ray spectra with Compton suppression using the spectrometer have been successfully performed during HL-2A discharges with different conditions. The performance of the spectrometer and the first experimental results are presented in this paper.

Time resolved absolute extreme ultraviolet radiation measurement on the ENN XuanLong-50 spherical tokamak.

A plasma radiation measurement system for a wide spectral range, based on compact Absolute eXtreme UltraViolet (AXUV) silicon photodiodes, has been implemented on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak. The system consists of two 16-channel AXUV16ELG arrays and one AXUV63HS1 single-cell detector mounted on ceramic sockets. The two arrays, facing toward the EXL-50 slim central post from two locations inside a top and a side ConFlat 400 port, have 32 view chords covering the interested plasma region in a poloidal cross section at toroidal 330°. The single-cell detector, seated on a retractable feedthrough, could be arranged flexibly with the help of an ultra-high vacuum compatible gate valve. The design details together with considerations on the EXL-50 specific engineering realities and physics requirements are described. Preliminary results from the EXL-50 2020 experimental campaign are presented.

Toroidal soft x-ray array on the EXL-50 spherical tokamak.

A toroidal soft x-ray array system for spectrum and intensity measurements on the EXL-50 spherical tokamak is described. Silicon drift detectors and digital multichannel analyzers are adopted for all 21 channels of the array, and an average energy resolution of 147 eV at 5.89 keV has been achieved at count rates over 500 kcps. In total, 20 channels of the array are symmetrically observed in both co- and counter-current directions on the EXL-50 mid-plane with a spatial resolution of around 10 cm, and the remaining one serves as a background reference channel. Tungsten emissions from tungsten coating of the limiters on the central post are observed. The influence of hard x rays on measured soft x-ray spectra and system operation is discussed.

Tangential hard x-ray diagnostic array on the EXL-50 spherical tokamak.

A tangential hard x-ray (HXR) diagnostic on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak for fast electron emission studies is presented. The HXR detection system consists of a symmetrical CdZnTe semiconductor detector array with a spectral sensitivity range of 20-300 keV. 25 channels have been designed on the 270° horizontal vacuum port with 12 sight lines to observe the forward emission, 12 sight lines to observe the backward emission of fast electrons, and 1 for viewing the central. Currently, ten channels have been in operation in the EXL-50 experiments. The systems are designed to measure the x-ray spectra for the estimation of fast electron temperature and electron velocity distribution in the EXL-50 experiment, which will be useful for understanding the dynamics of fast electrons generated by electron cyclotron resonance heating, for plasma instability and transport studies and for the analysis of plasma heating efficiency.

Prevalence of symptoms of childhood asthma, allergic rhinoconjunctivitis and eczema in the Pacific: the International Study of Asthma and Allergies in Childhood (ISAAC).

The International Study of Asthma and Allergies in Childhood (ISAAC) has provided valuable information regarding international prevalence patterns and potential risk factors for asthma, allergic rhinoconjunctivitis and eczema. However, the only Pacific countries that participated in ISAAC Phase I were Australia and New Zealand, and these included only a small number of Pacific children. Phase III has involved not only repeating the Phase I survey to examine time trends, but also to include centres and countries which are of interest but did not participate in Phase I. The ISAAC Phase III study was therefore conducted in the Pacific (in French Polynesia, New Caledonia, Tonga, Fiji Islands, Samoa, Cook Islands, Tokelau Islands and Niue). The overall prevalence rates of current symptoms (in the last 12 months) were 9.9% for asthma, 16.4% for allergic rhinoconjunctivitis and 10.7% for atopic eczema. The prevalence of current wheezing (9.9%) was generally much lower than that has been observed in Pacific children in New Zealand (31%), but there was considerable variation between the various Pacific centres: Tokelau Islands (19.7%), Tonga (16.2%), Niue (12.7%), French Polynesia (11.3%), Cook Islands (10.6%), Fiji Islands (10.4%), New Caledonia (8.2%) and Samoa (5.8%). The reasons for these differences in prevalence across the Pacific are unclear and require further research. The finding that prevalence levels are generally considerably lower than those in Pacific children in New Zealand adds to previous evidence that children who migrate experience an altered risk of asthma as a result of exposure to a new environment during childhood.

Management of impaired self-awareness in persons with traumatic brain injury.

AIM: To develop and evaluate a systematic intervention programme for the management of impaired self-awareness (ISD) in people with traumatic brain injury. METHODS: This study adopted a pre-test-post-test control group design. Twenty-one patients with traumatic brain injury were randomly assigned to an experimental group and a control group according to their admission sequence. The groups joined a newly developed Awareness Intervention Programme (AIP) and a conventional rehabilitation programme respectively for 4 weeks. Pre- and post-intervention outcome measures taken from the two groups were compared. Wilcoxon Signed-Ranks Tests were conducted to compare the within-group changes of the outcome measures of the Self-Awareness of Deficits Interview (SADI), the Functional Independence Measure (FIM) and the Lawton Instrumental Activities of Daily Living Score (Lawton IADL) in the control and experimental groups. Mann Whitney U-tests were conducted to compare the across-group differences of improvements of outcome measures between the participants in the two groups. RESULTS: After AIP training, the participants in the experimental group demonstrated significant improvement in their level of awareness as compared to the control group. However, the functional outcomes of the participants in experimental group did not show significant differences. CONCLUSION: The AIP can promote improvement in the level of self-awareness of people with traumatic brain injury. This new programme can be further developed to extend a better carryover treatment effect to functional improvement in daily activities.

Serum mannose-binding lectin levels and mbl2 gene polymorphisms in different age and gender groups of southern Chinese adults.

Mannose-binding lectin (MBL) is an acute-phase serum protein, and its inherited deficiency has been shown to predispose to infections. The developmental profile of serum MBL in preterm infants has been demonstrated previously. To determine the profiles of serum MBL levels and mbl2 polymorphisms over age and genders in an adult population, samples from 689 southern Chinese (age range 16-57 years; 382 males and 307 females) were studied using enzyme-linked immunosorbent assay and high-throughput genotyping of mbl2. Serum MBL levels maintained within a narrow range from age groups of 16-20 years old to 31-40 years old (mean of 2050-2160 micro g/l) and declined to a mean of 1466 micro g/l in the last age group 41-57 years old. No significant differences were found in the distributions of mbl2 haplotypes (YA, XA and YB) among all these age groups. Between gender groups, no significant imbalance of MBL profile in terms of serum MBL levels and distribution of mbl2 haplotypes was found. Results suggest an important role of circulating MBL in first-line host defence because MBL maintains at fairly constant levels after childhood and no gender influence on the MBL profile.

Psychological distress and negative appraisals in survivors of severe acute respiratory syndrome (SARS).

BACKGROUND: Severe acute respiratory syndrome (SARS) is a novel disease. The authors have limited knowledge of its impact on mental health. The present study aimed to examine the level and extent of psychological distress of SARS survivors following 1-month recovery, to explore patients' negative appraisals of the impact of SARS, and to evaluate the associations between psychological distress and negative appraisals. METHOD: The Beck Anxiety Inventory, the Beck Depression Inventory, and a newly developed measure, the SARS Impact Scale (SIS), were mailed to 453 Hong Kong Chinese SARS survivors discharged from hospital for 4 weeks or more. RESULTS: A total of 425 patients received the questionnaires and 180 (mean age 36.9 years; 120 women) gave valid replies. The response rate was 42.4 %. The participants also represented 13.6 % of all adult survivors in Hong Kong. About 35 % of respondents reported 'moderate to severe' or 'severe' ranges of anxiety and/or depressive symptoms. It was found that those working as healthcare workers or having family members killed by SARS were more prone to develop subsequent high levels of distress. Factor analyses extracted three meaningful factors of the SIS, namely 'survival threat', 'physical impact', and 'social impact'. Negative appraisals at the acute phase and 1-month recovery significantly accounted for substantial portions of variances for anxiety and depressive symptoms, after the effects of other psychosocial variables were controlled. CONCLUSIONS: Psychological distress of SARS survivors at 1-month recovery is real and significant. Negative appraisals may play a pivotal role in the development of psychological distress for SARS survivors, at least in the short term.

Microbiological aspects of diaper dermatitis.

BACKGROUND: The microbiological basis of diaper dermatitis is not clearly elucidated, although a better knowledge of microbial colonisation can be of importance with regard to an adequate treatment. OBJECTIVE: To investigate the relevance of candida sp. and Staphylococcus aureus colonisation in diaper dermatitis and to determine the correlation between the extent of colonisation and the severity of disease. METHODS: Growth of candida sp. and S. aureus in the perianal, inguinal and oral regions was determined by positive/negative and semi-quantitative analysis in an open, multi-centre (n = 3) study. Forty-eight children with healthy skin and 28 with diaper dermatitis were analysed. The severity of diaper dermatitis was assessed using a total symptoms score. RESULTS: Colonisation by candida sp. was significantly more frequent in children with diaper dermatitis as compared to those with healthy skin (perianal 75 vs. 19%; inguinal 50 vs. 10%; oral 68 vs. 25%, p < 0.0003), whereas colonisation by S. aureus at the 3 swab locations was not different (p > 0.34). There was a highly significant, positive correlation between severity of disease and extent of candida sp. colonisation at all swab locations. CONCLUSIONS: Limited microbial colonisation in diaper dermatitis is of questionable relevance, but extensive colonisation seems to aggravate the symptoms; therefore, we suggest that semi-quantitative evaluation should be preferred to the positive/negative assessment for a differential diagnosis.

Internal fixation of valgus-impacted humeral head fractures using the screw-wiring technique.

Between February 1996 and July 2000 eight patients (ages 35-74 years) with nine severely impacted humeral head fractures were operated on with the aim of preserving the humeral heads. Patients were treated surgically with open reduction, autologous bone grafting, and internal fixation with a screw-wiring technique. There were no complications and all patients were satisfied with the results. After 10-63 months there was no evidence of nonunion, arthritis, avascular necrosis, or loosening of implants. The mean Constant score was 83 (66-97) points. Results of this study support the observation that four-part valgus-impacted humeral head fractures without significant lateral displacement have a low incidence of avascular necrosis.

[Study on the relationship of high hematocrit with changes of the blood viscosity during in the environment of altitude hypoxia].

AIM: To investigate the relationship of high hematocrit with changes of the blood viscosity during in the environment of altitude hypoxia. METHODS: Index of hemorheology was determined from populations with different time of inhabit highland and normal controls. RESULTS: (1) Hematocrit and RBC deformability were higher in all highland populations than that in normal controls, these increase were time-dependent. (2) The blood viscosity was increased significantly during the early stage of inhabit highland, and restored normal in late stage. (3) RBC aggregability was reduced significantly with time-dependent in highland populations. (4) The oxygen content of tissue was reduced significantly during the early stage of inhabit highland, and restored normal in late stage. CONCLUSIONS: In the environment of altitude hypoxia, RBC deformability increase and RBC aggregability decrease can suppress blood viscosity increase induced by erythrocytosis, these compensatory regulation is help to maintain the normal oxygen content of tissue.

Chinese Frost Multidimensional Perfectionism Scale: a validation and prediction of self-esteem and psychological distress.

Recent research has shown that perfectionism is an important psychological variable in explaining various disorders. This study evaluated (a) the factor structure and psychometric properties of the Chinese Frost Multidimensional Perfectionism Scale (CFMPS) and (b) the relative predictive power of its subscales for self-esteem and psychological distress, including depressive, anxiety, and stress symptoms. Nine hundred and forty-seven Chinese adolescents from Hong Kong between 13 and 18 years of age participated in the study. Results indicated that five of the original six factors emerged in the factor analysis. The CFMPS and its subscales were found to have satisfactory internal consistencies. Replicating and extending previous findings, the factors "Concern over Mistakes" and "Doubt about Action" accounted for most of the variances of self-esteem and psychological distress. The factor "Organization" might have positive value on psychological health. Possible cultural influence on the development of perfectionism and limitations of the study are discussed.

Parallel synthesis of 3-aryloxy-2-propanolamines and evaluation as dual affinity 5-HT(1A) and 5-HT re-uptake ligands.

A solution phase synthesis for the preparation of 3-aryloxy-2-propanolamine libraries has been developed. This resulted in the identification of 5 as a ligand with dual affinity for 5-HT1A and serotonin reuptake receptors which shows excellent pharmacokinetic parameters.

Fluorination of 3-(3-(piperidin-1-yl)propyl)indoles and 3-(3-(piperazin-1-yl)propyl)indoles gives selective human 5-HT1D receptor ligands with improved pharmacokinetic profiles.

It has previously been reported that a 3-(3-(piperazin-1-yl)propyl)indole series of 5-HT1D receptor ligands have pharmacokinetic advantages over the corresponding 3-(3-(piperidin-1-yl)propyl)indole series and that the reduced pKa of the piperazines compared to the piperidines may be one possible explanation for these differences. To investigate this proposal we have developed versatile synthetic strategies for the incorporation of fluorine into these ligands, producing novel series of 4-fluoropiperidines, 3-fluoro-4-aminopiperidines, and both piperazine and piperidine derivatives with one or two fluorines in the propyl linker. Ligands were identified which maintained high affinity and selectivity for the 5-HT1D receptor and showed agonist efficacy in vitro. The incorporation of fluorine was found to significantly reduce the pKa of the compounds, and this reduction of basicity was shown to have a dramatic, beneficial influence on oral absorption, although the effect on oral bioavailability could not always be accurately predicted.

Measurement of anti-dsDNA: a comparative study of two ELISA and the Crithidia assay.

We compared the measurement of anti-dsDNA by a commercial ELISA test (DIASTAT), an in-house ELISA and the Crithidia luciliae assay in cross-sectional sera samples of 209 systemic lupus erythematosus (SLE) patients and 64 patients with a variety of rheumatological, autoimmune and non-autoimmune diseases in Hong Kong. The Crithidia assay was found to be the least sensitive (17%) but most specific (95%) method for detection of a positive result in SLE patients. The DIASTAT assay has a higher sensitivity (68%) but lower specificity (80%) than the in-house ELISA test (32% sensitivity and 89% specificity). The positive predictive value of the three assays are comparable at 90-92% while DIASTAT had the highest negative predictive value (44%). There was good linear correlation (r = 0.7) between the two ELISAs. ELISA can serve as a useful screening test for anti-dsDNA in SLE patients and doubtful cases can then be confirmed by another method such as radio-immunoassay.

Haemophilus parainfluenzae infective endocarditis.

Gram-negative endocarditis was uncommon in the past, accounting for 1% to 3% of cases. With the advent of antibiotics, immunosuppressive agents and narcotic abuse, the number has increased to 5% to 10% in the native valves and as high as 17% in the prosthetic valves, with Haemophilus species as the commonest aetiological agent, accounting for about 1% of the cases. We report a case of Haemophilus parainfluenzae endocarditis in a 39-year-old man who presented with heart failure and persistent fever. Echocardiography showed bi-leaflet mitral valve prolapse and severe mitral regurgitation. A small vegetation was seen at the flail anterior valve leaflet. He responded well to 4 weeks of intravenous ampicillin at 9 g/day and 2 weeks of gentamicin at 4 mg/kg/day, and subsequently underwent valve replacement.

Hyperhomocysteinaemia and premature coronary artery disease in the Chinese.

OBJECTIVES: To examine the prevalence of hyperhomocysteinaemia and compare it with the classic risk factors and vitamin status in Hong Kong Chinese patients with premature atherosclerotic coronary artery disease. DESIGN: Case-control study. SETTING: General hospital and community. SUBJECTS: Forty five patients (39 males) with significant coronary artery disease confirmed by angiography (32 post myocardial infarction) and 23 healthy volunteers (17 male), all aged less than 55 years. INTERVENTION: Standardised methionine-loading test. MAIN OUTCOME MEASURES: Coronary artery disease, risk factors. RESULTS: More patients than controls had fasting hyperhomocysteinaemia (10/45 v 2/23, P = 0.122), post-methionine hyperhomocysteinaemia (17/45 v 1/23, P = 0.008), and an abnormal response to methionine (15/45 v 1/23, P = 0.015). A history of smoking was more frequent in patients (3/23 v 25/45, P = 0.002). Sixteen of 17 patients with hyperhomocysteinaemia but only nine of 28 with normohomocysteinaemia were smokers (P = 0.0002). Fasting plasma cholesterol concentrations (mean (SD)) were higher in hyperhomocysteinaemic patients (6.41 (1.58) mmol/l) than in controls (5.53 (0.90) mmol/l) (P = 0.042). Serum vitamin B-12 was not reduced and serum folate was higher in hyperhomocysteinaemic patients (35 (4) nmol/l) than normohomocysteinaemic patients (26 (9) nmol/l) (P = 0.009). CONCLUSIONS: Although the prevalence of hyperhomocysteinaemia in Hong Kong Chinese is similar to that in white subjects, hyperhomocysteinaemia is not an independent risk factor for coronary artery disease and is associated with smoking. This may be of some consequence in view of the change to a more Western diet with more animal protein, and therefore methionine, coupled with a high frequency of cigarette smokers in this region. The causes of the hyperhomocysteinaemia are multifactorial but in this pilot study a deficiency of folate and/or vitamin B-12 did not seem to be one of them.

Understanding the culture and behaviour of East Asians--a Confucian perspective.

The economic miracle of East Asia is followed by the emergence of a new common identity in Confucianism among the nations in the region. Being the predominant cultural determining force in East Asia, Confucianism has deeply influenced East Asian behaviour. Three behavioural traits in East Asians are discussed. First, the East Asian's lack of "personality" is traced to the Confucian social institution of Li-rules of propriety. Second, the East Asian's lack of principled moral thinking is linked to the dyadic, relation-based character of the Confucian ethic, its lack of hypothetical reasoning and its hierarchical view of human relationships. Third, the East Asian's lack of assertiveness is rooted in the Confucian ideal of man as a reflection of harmony in the cosmos and the Confucian ideal of society as based on the fulfillment of duties rather than the assertion of rights. The implications of these Confucian traits suggest the need to re-formulate Western conceptions of and approaches to East Asian behaviour.

Cultural explanation of a 'psychosis' in a Chinese woman living in Australia.

This case report concerns a Malaysian-born Chinese woman living in the outback of Australia who was diagnosed as 'psychotic' and who recovered without drug treatment. A knowledge of her cultural background threw doubt on the assumption that her complaints were psychotic. The case shows the need to adopt cultural sensitivity in the practice of psychiatry.

Effects of pulse exposure to sublethal levels of hydrogen cyanide on reproduction of American flagfish.

American flagfish (Jordanella floridae) were exposed to intermittent cyanide concentrations ranging from 0.065 to 0.15 mg/L hydrogen cyanide to determine the effects upon the embryonic, juvenile, and adult stages of development along with hatching success and fry survival of the subsequent F1 generation. The most significant effect was observed following embryonic exposure to levels as low as 0.075 mg/L hydrogen cyanide from fertilization to hatching. Hatching success was reduced to 37% when compared with controls while egg production among those embryos which successfully completed hatching and reached sexual maturity was subsequently reduced by 30%. A 5-day exposure to levels as low as 0.065 mg/L during the embryonic and juvenile stage produced a 40% reduction in egg production at sexual maturity and a further 33% reduction in the hatching success of the F1 generation. Exposure during the embryonic and adult stage produced a 27% reduction in fecundity. The results also suggest that exposure during embryonic development is responsible for the identical but shortened estrous cycle and delayed sexual maturity observed following embryonic (Group A), embryonic and juvenile (Group B) and embryonic and adult (Group C) exposure to hydrogen cyanide.