Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks

无线传感器网络，作为全球未来十大技术之一，集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术，可实时感知、采集、处理、传输网络分布区域内的各种信息数据，在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议，并针对大规模的无线传感器网络设计了一种树状路由协议，它根据节点地址信息来形成路由，从而简化了复杂繁冗的路由表查找和维护，节省了不必要的开销，提高了路由效率，实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR（AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位：工学硕士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332007115216

Protein Kinase C Regulates Expression and Function of the Cav3.2 T-Type Ca²⁺ Channel during Maturation of Neonatal Rat Cardiomyocyte

Two distinct isoforms of the T-type Ca2+ channel, Cav3.1 and Cav3.2, play a pivotal role in the generation of pacemaker potentials in nodal cells in the heart, although the isoform switches from Cav3.2 to Cav3.1 during the early neonatal period with an unknown mechanism. The present study was designed to investigate the molecular system of the parts that are responsible for the changes of T-type Ca2+ channel isoforms in neonatal cardiomyocytes using the whole-cell patch-clamp technique and mRNA quantification. The present study demonstrates that PKC activation accelerates the Ni2+-sensitive beating rate and upregulates the Ni2+-sensitive T-type Ca2+ channel current in neonatal cardiomyocytes as a long-term effect, whereas PKC inhibition delays the Ni2+-sensitive beating rate and downregulates the Ni2+-sensitive T-type Ca2+ channel current. Because the Ni2+-sensitive T-type Ca2+ channel current is largely composed of the Cav3.2-T-type Ca2+ channel, it is accordingly assumed that PKC activity plays a crucial role in the maintenance of the Cav3.2 channel. The expression of Cav3.2 mRNA was highly positively correlated with PKC activity. The expression of a transcription factor Nkx2.5 mRNA, possibly corresponding to the Cav3.2 channel gene, was decreased by an inhibition of PKCβII. These results suggest that PKC activation, presumably by PKCβII, is responsible for the upregulation of CaV3.2 T-type Ca2+ channel expression that interacts with a cardiac-specific transcription factor, Nkx2.5, in neonatal cardiomyocytes

Direct free radical scavenging effects of water-soluble HMG-CoA reductase inhibitors

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, statins, are widely used for preventing cardiovascular and cerebrovascular diseases by controlling blood cholesterol level. Additionally, previous studies revealed the scavenging effects of statins on free radicals. We assessed direct scavenging activities of two water-soluble statins, fluvastatin and pravastatin, on multiple free radicals using electron spin resonance spectrometry with spin trapping method. We estimated reaction rate constants (kfv for fluvastatin, and kpv for pravastatin). Superoxide anion was scavenged by fluvastatin and pravastatin with kfv and kpv of 4.82 M−1s−1 and 49.0 M−1s−1, respectively. Scavenging effects of fluvastatin and pravastatin on hydroxyl radical were comparable; both kfv and kpv were >109 M−1s−1. Fluvastatin also eliminated tert-butyl peroxyl radical with relative kfv of 2.63 to that of CYPMPO, whereas pravastatin did not affect tert-butyl peroxyl radical. Nitric oxide was scavenged by fluvastatin and pravastatin with kfv and kpv of 68.6 M−1s−1 and 701 M−1s−1, respectively. Both fluvastatin and pravastatin had scavenging effects on superoxide anion, hydroxyl radical and nitric oxide radical. On the other hand, tert-butyl peroxyl radical was scavenged only by fluvastatin, suggesting that fluvastatin might have more potential effect than pravastatin to prevent atherosclerosis and ischemia/reperfusion injury via inhibiting oxidation of lipids

Upregulation of miR-30d in Persistent AF

Background: Atrial fibrillation (AF) begets AF in part due to atrial remodeling, the molecular mechanisms of which have not been completely elucidated. This study was conducted to identify microRNA(s) responsible for electrical remodeling in AF. Methods and Results: The expression profiles of 1205 microRNAs, in cardiomyocytes from patients with persistent AF and from age-, gender-, and cardiac function-matched control patients with normal sinus rhythm, were examined by use of a microRNA microarray platform. Thirty-nine microRNAs differentially expressed in AF patients’ atria were identified, including miR-30d, as a candidate responsible for ion channel remodeling by in silico analysis. MiR-30d was significantly upregulated in cardiomyocytes from AF patients, whereas the mRNA and protein levels of CACNA1C/ Cav1.2 and KCNJ3/Kir3.1, postulated targets of miR-30d, were markedly reduced. KCNJ3/Kir3.1 expression was downregulated by transfection of the miR-30 precursor, concomitant with a reduction of the acetylcholine-sensitive inward-rectifier K+ current (IK.ACh). KCNJ3/Kir3.1 (but not CACNA1C/Cav1.2) expression was enhanced by the knockdown of miR-30d. The Ca2+ ionophore, A23187, induced a dose-dependent upregulation of miR-30d, followed by the suppression of KCNJ3 mRNA expression. Blockade of protein kinase C signaling blunted the [Ca2+]i-dependent downregulation of Kir3.1 via miR-30d. Conclusions: The downward remodeling of IK.ACh is attributed, at least in part, to deranged Ca2+ handling, leading to the upregulation of miR-30d in human AF, revealing a novel post-transcriptional regulation of IK.ACh

Enhanced BDNF Actions Following Acute Hypoxia Facilitate HIF-1α-Dependent Upregulation of Cav3-T-Type Ca2+ Channels in Rat Cardiomyocytes

Brain-derived neurotrophic factor (BDNF) has recently been recognized as a cardiovascular regulator particularly in the diseased condition, including coronary artery disease, heart failure, cardiomyopathy, and hypertension. Here, we investigate the role of BDNF on the T-type Ca2+ channel, Cav3.1 and Cav3.2, in rat neonatal cardiomyocytes exposed to normoxia (21% O2) and acute hypoxia (1% O2) in vitro for up to 3 h. The exposure of cardiomyocytes to hypoxia (1 h, 3 h) caused a significant upregulation of the mRNAs for hypoxia-inducible factor 1α (Hif1α), Cav3.1, Cav3.2 and Bdnf, but not tropomyosin-related kinase receptor B (TrkB). The upregulation of Cav3.1 and Cav3.2 caused by hypoxia was completely halted by small interfering RNA (siRNA) targeting Hif1a (Hif1a-siRNA) or Bdnf (Bdnf-siRNA). Immunocytochemical staining data revealed a distinct upregulation of Cav3.1- and Cav3.2-proteins caused by hypoxia in cardiomyocytes, which was markedly suppressed by Bdnf-siRNA. These results unveiled a novel regulatory action of BDNF on the T-type Ca2+ channels expression through the HIF-1α-dependent pathway in cardiomyocytes