The applicability of the PTTL dose re-analysis method to the Harshaw LiF:Mg,Cu,P material

The phototransferred thermoluminescence (PTTL) technique is applied to the Harshaw LiF:Mg,Cu,P material. It is demonstrated that using 254-nm UV light, dose levels as low as 0.2 mGy can be re-estimated. The PTTL efficiency was found to be ～ 6 % in the dose range of 0.2 mGy-1 Gy, and it appears to be dose-independent. This implies that a simple calibration factor could be applied to the PTTL data for the re-estimation of dose levels. It was demonstrated that with a proper choice of the TL readout parameters, and the UV-light irradiation conditions, dose levels that are relevant to personal or environmental dosimetry can be re-estimated.     

双向IGBT开关在矩阵变换器中的应用

双向IGBT模块是实现高频矩阵变换器极为有效的方法。略不同于硬开关PWM变换器，矩阵变换器中的开关和传导损耗取决于所选的调制策略。本文介绍了一种由诺丁汉大学推导的平均损耗的计算公式。测试一个使用1200V，200A的双向模块实现的三相到单相的构造，得到的波形说明了矩阵变换器的实际操作以及可能会出现的输出电流纹波。     

Calculation of Viscous EHL Traction for Squalane Using Molecular Simulation and Rheometry

Recently, remarkable agreement was reported between nonequilibrium molecular dynamics simulation and high-pressure Couette rheometry on squalane. We have utilized the viscosity-strain rate relationship obtained from this unique combination of experimental and simulation data along with high-pressure viscometer measurements to calculate the viscous traction curve in the elastohydrodynamic lubrication (EHL) regime. A comparison with measured traction at 0.57 and 1.29 GPa shows excellent agreement, confirming the validity of the measurements and simulations. Thus, we present for the first time, a successful calculation of EHL traction from the liquid shear response obtained from both molecular dynamics and rheometry.     

Two dual-specific (anti-IgG and anti-dsDNA) monoclonal autoantibodies derived from the NZB/NZW F1 recognize an epitope in the hinge region

The anti-IgG properties of two dual-specific (anti-dsDNA and anti-IgG) monoclonal NZB/NZW F1-derived autoantibodies, BV 17-45 and BV 16-13, were studied to resolve the location and possible commonality of the IgG epitope. To determine if BV 17-45 and BV 16-13 recognized the same IgG epitope, the relative temperature sensitivity of the conformational IgG epitopes were evaluated using the conformational sensitive immunoassay. Comparison of the temperature sensitivity of the conformational immunoglobulin epitopes over a temperature range of 25-100 degrees C suggested that the epitope recognized by BV 17-45 was the same as the IgG epitope recognized by BV 16-13. Further studies with papain- and pepsin-generated F(ab')2, Fab, and Fc fragments of BV 17-45 and BV 16-13 revealed that the dual-specific autoantibodies BV 17-45 and BV 16-13 both bound an epitope in the hinge region of the IgG molecule. The potential correlation between these studies and the pathogenic nature of dual-specific autoantibodies is discussed.     

Toynbee Memorial Lecture 1997. Middle ear mechanics in normal, diseased and reconstructed ears

A review of the structure-function relationships in normal, diseased and reconstructed middle ears is presented. Variables used to describe the system are sound pressure, volume velocity and acoustic impedance. We discuss the following: (1) Sound can be transmitted from the ear canal to the cochlea via two mechanisms: the tympanoossicular system (ossicular coupling) and direct acoustic stimulation of the oval and round windows (acoustic coupling). In the normal ear, middle-ear pressure gain, which is the result of ossicular coupling, is frequency-dependent and smaller than generally believed. Acoustic coupling is negligibly small in normal ears, but can play a significant role in some diseased and reconstructed ears. (2) The severity of conductive hearing loss due to middle-ear disease or after tympanoplasty surgery can be predicted by the degree to which ossicular coupling, acoustic coupling, and stapes-cochlear input impedance are compromised. Such analyses are used to explain the air-bone gaps associated with lesions such as ossicular interruption, ossicular fixation and tympanic membrane perforation. (3) With type IV and V tympanoplasty, hearing is determined solely by acoustic coupling. A quantitative analysis of structure-function relationships can both explain the wide range of observed post-operative hearing results and suggest surgical guidelines in order to optimize the post-operative results. (4) In tympanoplasty types I, II and III, the hearing result depends on the efficacy of the reconstructed tympanic membrane, the efficacy of the reconstructed ossicular chain and adequacy of middle-ear aeration. Currently, our knowledge of the mechanics of these three factors is incomplete. The mechanics of mastoidectomy and stapedectomy are also discussed.     

Vertical transmission of hepatitis C virus in New Zealand

AIMS: To investigate the transmission of hepatitis C virus from viraemic mothers to infants. METHODS: The study group comprised 54 hepatitis C ribonucleic acid (RNA) positive, human immunodeficiency virus (HIV) negative women attending antenatal clinic, their infants when born, 12 previous children and 44 children of 29 additional nonpregnant, viraemic women. During the study period there were 60 live births (1 set of twins, 5 sequential pregnancies). All infants were tested at birth for hepatitis C virus (HCV) RNA. Thirty infants were retested at 6 months or later. Breast milk from 30 mothers was tested for HCV RNA. The 56 other children were tested for antibody to HCV and HCV RNA. RESULTS: Of the 60 infants tested at birth, 30 failed to attend a 6 month or later followup, 2 infants were HCV viraemic by six months of age, 2 infants had one episode of possible HCV RNA positivity followed by loss of detectable HCV RNA and 26 have shown no evidence of HCV infection. Five of the 30 breast milk samples tested were positive for HCV RNA. Four older children of viraemic mothers were HCV RNA positive. CONCLUSIONS: In this study, 2 of 30 (6.6%) of infants born to HIV negative, HCV viraemic mothers acquired HCV infection. Breast milk remains a possible contributory source of infant HCV infection. Management of babies born to HCV viraemic mothers should include retesting of baby for HCV RNA at 3 to 6 months of age.     

Sibling conflict in middle childhood predicts children's adjustment in early adolescence.

Associations between sibling conflict in middle childhood and psychological adjustment in early adolescence were studied in a sample of 80 boys and 56 girls. Parents and children provided self-report data about family relationships and children's adjustment. Parents' hostility to children was assessed from videotaped interactions. Results showed that sibling conflict at Time 1 predicted increases in children's anxiety, depressed mood, and delinquent behavior 2 years later. Moreover, earlier sibling conflict at Time 1 accounted for unique variance in young adolescents' Time 2 anxiety, depressed mood, and delinquent behavior above and beyond the variance explained by earlier maternal hostility and marital conflict. Children's adjustment at Time 1 did not predict sibling conflict at Time 2. Results highlight the unique significance of the earlier sibling relationship for young adolescents' psychological adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The examination of myofascial face pain and its relationship to psychological distress among women.

In this study, 110 female myofascial face pain patients were assessed monthly for 10 months on measures of pain, distress, and stressful life events. D. A. Kenny and A. J. Zautra's (1995) structural equation model for examining the separate trait, state, and error components of the variables was used to analyze the data. Both pain and distress had sizable trait variance, and the trait components were correlated. The 2 variables also showed sizable state variance, and the states of pain covaried with states of distress. A significant time-lagged relationship between the 2 variables was found: Increases in distress led to elevations in pain 1 mo later. Stressful life events arising from major social roles were also associated with greater distress, but not pain. Illness events unrelated to the pain syndrome were associated with both pain and distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Donor factors affecting outcome after pancreas transplantation

In this study, we demonstrated that Px grafts from donors older than 45 years are associated with an increased risk of developing poor glycemic control and premature loss of Px function. Previous studies corroborate our finding that age of the donor is the principal donor characteristic impacting postoperative Px survival. Whereas prior studies also implicated hyperamylasemia as a factor which contributes adversely to outcome, we were unable to demonstrate a significant influence of donor hyperamylasemia on long-term graft survival, although it did correlate with the degree of immediate postoperative pancreatitis and with the need for oral hypoglycemic agents. Similarly, elevated blood glucoses in the donor, which can be a result of many other factors unrelated to the quality of the graft, did not predict a poor outcome in the recipient. NHB donor pancreata did as well as HB pancreata with regards to all postoperative functional parameters. A marginally increased risk of developing major complications was associated with older donors. Despite the frequent use of non-ideal donors, including older and NHB donors, excellent overall Px graft survival can be achieved. Although the quality of the pancreas graft was not directly addressed in this study, we believe irrespective of hyperglycemia or hyperamylasemia, subjective assessment of organ quality by an experienced transplant surgeon is the most important determinant of suitability.     

Leadership Behavior and Subordinate Well-Being.

The authors used a longitudinal design to investigate the relation between leadership behavior and the well-being of subordinates. Well-being is conceptualized as people's feelings about themselves and the settings in which they live and work. Staff members (N = 562) of 2 Community Trusts participated 4 times in a 14-month period. Five models were formulated to answer 2 questions: What is the most likely direction of the relation between leadership and well-being, and what is the time frame of this relation? The model with the best fit suggested that leadership behavior and subordinate responses are linked in a feedback loop. Leadership behavior at Time 1 influenced leadership behavior at Time 4. Subordinate well-being at Time 2 synchronously influenced leadership behavior at Time 2. Leadership behavior at Time 4 synchronously influenced subordinate well-being at Time 4. (PsycINFO Database Record (c) 2010 APA, all rights reserved)