Applicability of Pre-Plastic Deformation Method for Improving Mechanical Properties of Bulk Metallic Glasses.

Pre-plastic deformation (PPD) treatments on bulk metallic glasses (BMGs) have previously been shown to be helpful in producing multiple shear bands. In this work, the applicability of the PPD approach on BMGs with different Poisson's ratios was validated based on experimental and simulation observations. It was found that for BMGs with high Poisson's ratios (HBMGs, e.g., Zr56Co28Al16 and Zr46Cu46Al8), the PPD treatment can easily trigger a pair of large plastic deformation zones consisting of multiple shear bands. These PPD-treated HBMGs clearly display improved strength and compressive plasticity. On the other hand, the mechanical properties of BMGs with low Poisson's ratios (LBMG, e.g., Fe48Cr15Mo14Y2C15B6) become worse due to a few shear bands and micro-cracks in extremely small plastic deformation zones. Additionally, for the PPD-treated HBMGs with similar high Poisson's ratios, the Zr56Co28Al16 BMG exhibits much larger plasticity than the Zr46Cu46Al8 BMG. This phenomenon is mainly due to more defective icosahedral clusters in the Zr56Co28Al16 BMG, which can serve as nucleation sites for shear transformation zones (STZs) during subsequent deformation. The present study may provide a basis for understanding the plastic deformation mechanism of BMGs.

[Clinical observation on acupoint injection of VitB12 for treatment of trigeminal neuralgia].

OBJECTIVE: To probe a better method for treatment of trigeminal neuralgia. Methods One hundred and four cases of trigeminal neuralgia were randomly divided into a treatment group (n=57) and a control group (n=47). The treatment group were treated witb acupoint injection of 2000 microg of VitB12, with Xiaguan (ST 7) selected as main point, and the control group witb oral administration of Carbamazepine. The therapeutic effect were analyzed after 3 tberapeutic courses. RESULTS: Tbe cured and markedly effective rate and the effective rate were 82.5% and 98.2% in the treatment group, and 57.4% and 8O.9% in the control group, with a very significant difference between the two groups (P < 0.01). After treatment, there was a very significant difference in the cumulative score of pain between the two groups (P < 0.01). CONCLUSION: Acupoint injection of VitB12 has a better therapeutic effect than that of oral administration of Carbamazepine.

[Relationships between the diameters of Bacille Calmette-Guerin scars and asthma, atopy in urban and rural Beijing children].

OBJECTIVE: To compare the diameters of Bacille Calmette-Guerin (BCG) scars between asthmatic (allergic) students and normal students, and to compare the diameters of BCG scars in children in rural Beijing area with those in urban Beijing area, and to compare the prevalence of asthmatic (allergic) symptoms and atopy between rural and urban Beijing students. METHODS: Sampled by cluster-random Method, 819 urban school children and 1 044 rural school children aged 13 - 14 years were recruited for the Beijing arm of the phase III international study of asthma and allergies in childhood. The children answered the core questionnaires, and underwent skin prick test for 13 allergens, and were checked for BCG scars on their arms. RESULTS: (1) In both rural and urban Beijing students, the mean diameters of BCG scars in those with asthma (allergy) (asthma ever, wheeze ever, current wheeze within 12 months, hay fever ever, repeated rash ever, eczema ever, allergic rhinitis, atopy, high-sensitivity or were diagnosed asthma) were (7.0 +/- 2.1) mm-(8.8 +/- 2.8) mm, which were not significantly different from those of (7.2 +/- 2.7) mm-(8.2 +/- 2.2) mm in normal students (P > 0.05). (2) Compared to the urban students, the mean diameter of BCG scars in the rural students was (8.2 +/- 2.3) mm, significantly larger than that of (7.3 +/- 2.9) mm in the urban students (P < 0.01). The prevalence of asthma (allergy) (asthma ever, wheeze ever, current wheeze within 12 months, hay fever ever, repeated rash ever, eczema ever, allergic rhinitis, atopy, high-sensitivity or diagnosed asthma) were 0.6% - 11.4% in the rural Beijing students, significantly lower than that of 3.1% - 35.7% in urban Beijing schoolchildren (P < 0.01). CONCLUSIONS: The diameters of BCG scars were not significantly different between asthmatic (allergic) students and normal students. The diameters of BCG scars in the rural students were significantly larger than those in the urban students. The prevalence of asthma and allergy in the rural children were significantly lower than that in the urban students. The results suggest that there is difference in immunity between rural and urban children from early life, which may be caused by the different living environments.

The investigation of factors influencing the measurement of thyroid stimulating hormone in dried blood spots on filter paper.

We investigated sample collection variables that may influence the measurement of the thyroid stimulating hormone (TSH) including: time after birth, season, different ways for blood spot drying and varied elution time from filter paper. TSH was measured with an enzyme-linked immunoassay (EIA) method on dried blood spots collected from newborns and/or external quality control materials from CDC. We found that TSH results were stable if specimens were collected from newborns 72 hours after birth. We obtained different results when TSH was measured during different seasons. The results also changed as the specimens were dried in different ways. The length of time for eluting from the DBS also exerted influence on the TSH measurement. In order to assure newborn screening quality, all factors influencing the results should be considered and the best condition for testing chosen. The specimen should be collected from babies at 3-6 days of age and air-dried at room temperature. Different cut-offs may be necessary for different seasons of the years.