Direct formation of small Cu2O nanocubes, octahedra, and octapods for efficient synthesis of triazoles.

In most studies describing the preparation of Cu2O crystals of various morphologies, the particle sizes are normally hundreds of nanometers to micrometers due to rapid particle growth, so they are not exactly nanocrystals. Here we report surfactant-free formation of sub-100 nm Cu2O nanocrystals with systematic shape evolution from cubic to octahedral structures by preparing an aqueous mixture of Cu(OAc)2, NaOH, and N2H4 solution. Adjustment of the hydrazine volume enables the particle shape control. Uniform nanocubes and octahedra were synthesized with edge lengths of 37 and 67 nm, respectively. Novel Cu2O octapods with an edge length of 135 nm were also produced by mixing CuCl2 solution, SDS surfactant, NaOH solution, and NH2OH · HCl reductant solution. All of them are nearly the smallest Cu2O nanocrystals of the same shapes ever reported. These small cubes, octahedra, and octapods were employed as catalysts in the direct synthesis of 1,2,3-triazoles from the reaction of alkynes, organic halides, and NaN3 at 55 °C. All of them displayed high product yields in short reaction times. The octahedra enclosed by the {111} facets are the best catalysts, and can catalyze this cycloaddition reaction with high yields in just 2 h when different alkynes were used to make diverse triazole products. Hence, the small Cu2O particles provide time-saving, energy-efficient, and high product yield benefits to organocatalysis.

Arteriovenous malformation of the mandible presented as massive upper gastrointestinal bleeding: report of one case.

Arteriovenous malformation is an uncommon cause of upper gastrointestinal bleeding in children. It should be taken into consideration when a child has upper gastrointestinal bleeding because without proper management, it might be fatal. We report a 10-year-old boy whose initial presentation was massive hematemesis and impending shock. After angiography, arteriovenous malformation (AVM) of the mandible was found and treated with embolization. This 10-year-old boy also had chicken pox during admission. Case reports regarding AVM of dental arches in literature are reviewed and the proposed managements are summarized. Embolization combined with surgical excision might be the optimal way to manage AVM of dental arches.

Rubella seroprevalence among young women taipei county after routine measles, mumps and rubella immunization program.

To better target rubella immunization efforts by determining the age-specific rubella seroprevalence and the related factors for children in Taiwan after the 1986 national vaccine policy. A cross-sectional study was conducted for these girls aged 10 years (1994 cohorts), 13 years (1991 cohorts), 16 years (1988 cohorts), and 19 to approximately 22 years (1982-1985 cohorts), respectively, in 2004 in Taipei county. Participants were given a questionnaire detailing family income, education level, ethnicity of mother, number of siblings, and history of rubella infection. Possible predictors of rubella seropositivity and differences in seroprevalence were calculated by multivariate logistic regression analysis. A total of 826 cases were recruited. The geometric mean titer of rubella IgG antibody was 60.7 +/- 2.1 IU/ml. Rubella seropositive rates were 282/287 (98.3%) in children aged 10 years, 234/235 (99.6%) in aged 13 years, 179/185 (96.8%) in aged 16 years, and 110/119 (92. 4%) in aged 19-22 years. Older age, low maternal education level, and foreign mothers were correlated with seronegativity (p < 0.05). The MMR vaccine program has induced effectively the immunity against rubella. However, to eliminate congenital rubella syndrome, more effort should be taken for the vaccination of susceptible adolescents and young women.

Clinical criteria for diagnosing perforated appendix in pediatric patients.

OBJECTIVE: To determine predictive variables associated with a perforated appendix in pediatric patients with acute appendicitis. METHODS: This is a retrospective, cross-sectional, observational study from a medical center with more than 2000 beds (230 beds in Department of Pediatrics and Pediatric Surgery), with a mean admission of more than 12000 cases and 2200 surgeries per year. The outcome variable was perforated appendix, and the predictive variables included demographic and clinical factors. RESULTS: During a 6-year period, appendectomies were performed on 274 patients ranging in age from 1 to 18 years. Perforated appendix was found in 100 children (36.5%). Predictive factors significantly associated with perforated appendix were age younger than 9 years, abdominal pain of more than 2 days' duration, temperature of more than 37.9 degrees C, peritoneal signs, and erythrocyte sedimentation rate of more than 25 mm/h. Abdominal ultrasound was performed in 89 patients (32%). For perforated appendix, the ultrasound had a sensitivity of 35%, specificity of 98%, positive predictive value of 95%, and negative predictive value of 55%. Indications for an abdominal ultrasound were determined from a scoring system using the predictive variables significantly associated with perforated appendix. CONCLUSION: The use of our proposed scoring system to determine the indications to perform an abdominal ultrasound may prove to assist in deciding treatment (medical vs surgical) for children with perforated appendix. Initial antibiotic treatment followed by interval appendectomy would become a more likely treatment option if our study results can be validated in a prospective study.

Correlation between age and allergens in pediatric atopic dermatitis.

BACKGROUND: There has been significant progress recently in the clinical investigation of atopic dermatitis (AD), especially in the recognition of aeroallergens as aggravating factors in AD. However, sensitization to food allergens and aeroallergens in children with AD has not been fully studied. OBJECTIVE: To evaluate the correlation between age and allergens in children with AD. METHODS: A retrospective cross-sectional study was performed between January 1, 1999, and December 31, 2002, on 262 children with a definitive diagnosis of AD aged 0 to 16 years. Comparison of 3 age groups (<2 years, 2-5 years, and >5 years) with the correlation of food allergens and aeroallergens using the CAP-FEIA test was made using linear regression and logistic regression analyses. RESULTS: In children younger than 2 years, AD was associated with food allergens. In children aged 2 to 5 years, both food allergens and aeroallergens played an important role. In children older than 5 years, only elevated aeroallergen specific IgE levels were noted (P < .02). Age correlated negatively with food allergens and positively with aeroallergens after adjusting for sex (P < .04). Sensitization to aeroallergens may correlate with acquisition of the respiratory symptoms of the atopic state. CONCLUSIONS: Food allergens may be the major trigger of AD in early life, after which the role of environmental aeroallergens become more important and may be associated with respiratory sensitization.