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21.
Two carpenters developed rhinitis, conjunctivitis, bronchial wheezing, and dyspnoea while using obeche (Triplochiton scleroxylon, African maple) at their work while they built saunas. Skin prick tests showed an immediate reaction, specific IgE to obeche was detected in their serum, and bronchial provocation test with obeche gave an immediate reaction with decrease of FEV1 and PEF values. The symptoms disappeared after avoiding the use of obeche. Obeche may cause a health hazard to carpenters who are exposed to this dust and who may develop allergic symptoms after the exposure.  相似文献   
22.
AIM: To assess potencies of tetrahydroprotoberberines (THPB) and hydrobenzyltetrahydroisoquinolines (HBTI) on DA receptors. METHODS: The receptor binding assay with calf striatum to D1 and D2 receptors, and the animal behavior tests were used. RESULTS: (+/-) 12-Chloroscoulerine (CSL) was the most potent one among the THPB and HBTI. The affinities of CSL to D1 and D2 receptors were 13 and 51 nmol.L-1, respectively. In rats, CSL showed an antagonistic effect on the stereotypy and induced catalepsy. In the 6-OHDA lesioned rats, however, CSL exerted the agonistic effect to DA receptors. CONCLUSION: CSL had dual actions to DA receptors and its effects were similar to that of (-)stepholidine.  相似文献   
23.
OBJECTIVE: To determine whether long-term very vigorous endurance training prevents hypertension. DESIGN: Cohort study of master orienteering runners and controls. SETTING: Finland. SUBJECTS AND METHODS: In 1995, a health questionnaire was completed by 264 male orienteering runners (response rate 90.4%) who had been top-ranked in competitions among men aged 35-59 years in 1984, and by 388 similarly aged male controls (response rate 87.1%) who were healthy at the age of 20 years and free of overt ischemic heart disease in 1985. MAIN OUTCOME MEASURE: Self-report of medication for hypertension. RESULTS: In the endurance athlete group, the crude prevalence (8.7%) of subjects who had used medication for hypertension was less than a third of that in the control group (27.8%). Even after adjusting for age and body mass index, the difference between the groups was still significant (odds ratio for athletes 0.43, 95% confidence interval 0.25-0.76). CONCLUSIONS: Long-term vigorous endurance training is associated with a low prevalence of hypertension. Some of the effect can be explained by a lower body mass, but exercise seems to induce a lower rate of hypertension by other mechanisms than by decreasing body weight  相似文献   
24.
25.
This paper presents a fully automated method for segmenting articular knee cartilage and bone from in vivo 3-D dual echo steady state images. The magnetic resonance imaging (MRI) datasets were obtained from the Osteoarthritis Initiative (OAI) pilot study and include longitudinal images from controls and subjects with knee osteoarthritis (OA) scanned twice at each visit (baseline, 24 month). Initially, human experts segmented six MRI series. Five of the six resultant sets served as reference atlases for a multiatlas segmentation algorithm. The methodology created precise knee segmentations that were used to extract articular cartilage volume, surface area, and thickness as well as subchondral bone plate curvature. Comparison to manual segmentation showed Dice similarity coefficient (DSC) of 0.88 and 0.84 for the femoral and tibial cartilage. In OA subjects, thickness measurements showed test-retest precision ranging from 0.014 mm (0.6%) at the femur to 0.038 mm (1.6%) at the femoral trochlea. In the same population, the curvature test-retest precision ranged from 0.0005 mm(-1) (3.6%) at the femur to 0.0026 mm(-1) (11.7%) at the medial tibia. Thickness longitudinal changes showed OA Pearson correlation coefficient of 0.94 for the femur. In conclusion, the fully automated segmentation methodology produces reproducible cartilage volume, thickness, and shape measurements valuable for the study of OA progression.  相似文献   
26.
In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m2, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m2, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.  相似文献   
27.
The relationship between written and spoken words is convoluted in languages with a deep orthography such as English and therefore it is difficult to devise explicit rules for generating the pronunciations for unseen words. Pronunciation by analogy (PbA) is a data-driven method of constructing pronunciations for novel words from concatenated segments of known words and their pronunciations. PbA performs relatively well with English and outperforms several other proposed methods. However, the method inherently generates several candidate pronunciations and its performance depends critically on a good scoring function to choose the best one of them.Previous PbA algorithms have used several different scoring heuristics such as the product of the frequencies of the component pronunciations of the segments, or the number of different segmentations that yield the same pronunciation, and different combinations of these methods, to evaluate the candidate pronunciations. In this article, we instead propose to use a probabilistically justified scoring rule. We show that this principled approach alone yields better accuracy than any previously published PbA algorithm. Furthermore, combined with certain ad hoc modifications motivated by earlier algorithms, the performance can in some cases be further increased.  相似文献   
28.
We introduce a new algorithm for computing an approximately optimal binary search tree with known access probabilities or weights on items. The algorithm is simple to implement and it has two contributions. First, a randomized variant of the algorithm produces a binary search tree with expected performance that improves the previous theoretical guarantees (the performance is dependent on the value of the input random variable). More precisely, if p is the probability of accessing an item, then under expectation the item is found after searching lg1/p+0.087+lg2(1+pmax) nodes, where pmax is the maximal probability among items. The previous best bound was lg1/p+1, albeit deterministic. For the optimal tree our upper bound implies a non-constructive performance bound of H+0.087+lg2(1+pmax), where H is the entropy on the item distribution and the previous bound was H+1. The second contribution of the algorithm is a low cost in i/o models of cost such as the cache-oblivious model, while attaining simultaneously the above bound for the produced tree.  相似文献   
29.
HIV-positive mothers living in Toronto, ON, face myriad economic and social challenges that put them at risk for housing instability and homelessness. These challenges are exacerbated for mothers from African and Caribbean communities as they navigate a web of shelter, housing, health care and social care systems that do not adequately address their social positioning as HIV-positive and racialized mothers. To date, there is a dearth of research that has taken a cultural, ethnoracial and gendered lens to explore these issues, and consequently, little is known about their experiences of housing instability as it intersects with issues related to motherhood, poverty, sexism, racism, immigration status and HIV-related stigma and discrimination. This paper presents findings from the HIV, Housing and Families community-based research study and highlights the unique and complex housing issues African and Caribbean mothers facing by living with HIV in Toronto. Implications for policy and practice are also discussed.  相似文献   
30.
The suitability of different types of telechelic poly(lactic acid) (PLA) copolymers for dilactide production and prepolymer products was evaluated. L ‐lactic acid (L ‐LA) was copolymerized with 1,4‐butanediol, pentaerythritol, adipic acid, or 1,2,3,4‐butanetetracarboxylic acid (1,2,3,4‐BTCA). The influence of branching, the choice of catalyst, and the type of terminal groups on the properties and the thermal stability of the end product was determined. Carboxyl‐termination of PLA was shown to lead to higher molar masses than hydroxyl‐termination. The observed differences in the molar masses were explained by the lower thermal stability of the hydroxyl‐terminated PLA, as evidenced by the faster depolymerization rate of the hydroxyl‐terminated polymers and their higher tendency to undergo racemization. Sn(Oct)2 was found to be a more effective copolymerization catalyst than Fe(OAc)2 in terms of the final molar masses obtained. It was additionally found that the amount of chains not attached to the comonomers decreased toward longer polymerization times and was typically higher for the hydroxyl‐terminated copolymers. The results suggest that predominant carboxyl‐termination would increase the thermal stability of PLA polymers, whereas hydroxyl‐termination could be utilized to increase the production speed and efficiency of dilactide. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   
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