基于蓝牙的多机通信的实现及其应用

本文提出了一种基于蓝牙通信协议的PC机监控多台单片机控制系统的多机通信方案。针对蓝牙芯片PTR2000,对多机通信的设计方法、系统的组成原理进行了阐述;对上位机蓝牙接口电路、单片机蓝牙接口电路的实现过程进行了详细的说明;对蓝牙通信协议,特别是大数据传输协议进行了设计。以汉字传输过程为例,提出了一种提取汉字的点阵算法,对上下位机之间进行汉字传输的软件设计与实现过程进行了说明,对实验结果进行了分析。实验结果表明,上述通信方案是成功的和有效的。     

Immunogenetics of the A-E alloantigen complex

OBJECTIVE: To examine noradrenergic (NA) function in children with attention-deficit hyperactivity disorder (ADHD) by replicating and expanding upon a previous finding that ADHD children with and without reading disabilities (RD) differ in plasma levels of the NA metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG). METHOD: Plasma levels of MHPG were compared in ADHD children who were subdivided on the basis of the presence or absence of RD. Subsequently, this replication sample was combined with a previously studied sample to further explore the relationship between plasma MHPG levels and measures of cognitive function in children with ADHD. RESULTS: Plasma levels of MHPG were significantly lower in ADHD children without RD, compared with those with RD, replicating a published finding. Analyses in the combined sample indicated that, among children with ADHD, plasma MHPG levels were inversely associated with measures of academic achievement and verbal processing, but not parent or teacher ratings of behavior or continuous performance test measures of attention and impulsivity. CONCLUSIONS: These data indicate that children with ADHD are not homogeneous with regard to NA function and that neurochemical variation is closely associated with differences in clinical characteristics of the children.     

Role of cardiac markers in evaluation of suspected myocardial infarction. Selecting the most clinically useful indicators

In the workup of a patient with chest pain, knowing which cardiac marker or markers to measure is not always easy. Many factors affect the choice of the most clinically effective test: elapsed time after onset of pain, possible presence of skeletal muscle injury, potential delays in receiving test results, to name a few. In this review article, Dr Mercer compares the current cardiac markers, rates them according to the 10 characteristics of the ideal marker, and offers guidelines for selecting the appropriate marker in various clinical settings.     

Is duodenal gastric metaplasia a consequence of Helicobacter pylori infection in children?

BACKGROUND: Duodenal gastric metaplasia (DGM) is commonly found in association with Helicobacter pylori (Hp)-associated gastritis in adults. DGM is also considered a risk factor for duodenal ulcer development. The prevalence of DGM in children and its association with gastritis, duodenitis, or the presence of Hp organisms is not clear. We investigated the prevalence of DGM in children and explore its association with several possible risk factors, including age, gender, gastritis, duodenitis, or Hp presence in the gastric antrum. METHODS: A retrospective analysis of 173 upper endoscopy procedures performed between 1993 and 1995 at Cabell Huntington Hospital, Huntington, WV, was done. Gastric and duodenal biopsies were stained with Giemsa for Hp detection, periodic acid-Schiff for DGM, and hematoxylin and eosin for histologic assessment. Gastric mucosal inflammation was graded according to Sydney criteria. RESULTS: Duodenal gastric metaplasia was identified in 23 of 173 (13%) patients. Duodenitis but not age, gender, gastritis, or the presence of Hp in the gastric antrum was associated with DGM development. In 4 of 23 DGM foci, Hp was identified. CONCLUSIONS: In children, DGM is not the consequence of Hp infection.     

Compromised allograft rejection response in transgenic mice expressing antisense sequences to retinoic acid receptor beta2

Our aim was to identify new genes involved in the cellular aspects of defense mechanism of Drosophila, as well as in melanotic tumor formation processes that are linked to blood cell disregulation. We have screened 1341 enhancer detector fly lines for expression of the lacZ reporter gene in larval hemocytes at the end of the third instar. We have selected 21 lines in which we observed a reproducible lacZ expression in blood cells. These lines were classified according to the subsets of hemocytes in which lacZ was expressed, and we identified five lines that can be used as lamellocyte markers. Three lines were selected for further analysis. The first exhibited strong lacZ expression in all lamellocytes. The second expressed lacZ in plasmatocytes and lamellocytes, and exhibited a melanotic tumor phenotype in larvae homozygous for the insertion. A third line showed a striking insertion-linked phenotype of melanized lymph glands (the hematopoietic organ), which resulted in the total absence of circulating hemocytes in the mutant larvae. We anticipate that this mutation, which we named domino, will prove a useful tool in the analysis of the role of hemocytes during the various aspects of immune response and melanotic tumor formation.