125 research outputs found

    Simulation of position-based routing algorithms in wireless ad hoc networks with irregular transmission ranges

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    In wireless mobile ad hoc networks (MANETs), there are two main categories of routing protocols: flooding-based and position-based. Flooding-based protocols waste precious bandwidth in wireless networks; while position-based protocols attempt to reduce the bandwidth used for control traffic. Many of the position-based protocols use a unit disk graph model for the network and thus implicitly assume a uniform transmission range for mobile hosts. However, this assumption may not be true in reality. Due to the irregular transmission range, it may not be as straightforward to extract a planar and connected subgraph on which to perform routing. In [1], a position-based routing algorithm that can handle irregular transmission range and guarantee delivery of messages is presented. In this project, we simulate the irregular transmission range scenario and compare the performance of five routing protocols in this scenario: Dijkstra's shortest path[4], Greedy routing[13], Perimeter routing[3], GPSR[10] and RPBR[1

    Liquid chromatography coupled with time-of-flight and ion trap mass spectrometry for qualitative analysis of herbal medicines

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    AbstractWith the expansion of herbal medicine (HM) market, the issue on how to apply up-to-date analytical tools on qualitative analysis of HMs to assure their quality, safety and efficacy has been arousing great attention. Due to its inherent characteristics of accurate mass measurements and multiple stages analysis, the integrated strategy of liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOF-MS) and ion trap mass spectrometry (IT-MS) is well-suited to be performed as qualitative analysis tool in this field. The purpose of this review is to provide an overview on the potential of this integrated strategy, including the review of general features of LC-IT-MS and LC-TOF-MS, the advantages of their combination, the common procedures for structure elucidation, the potential of LC-hybrid-IT-TOF/MS and also the summary and discussion of the applications of the integrated strategy for HM qualitative analysis (2006–2011). The advantages and future developments of LC coupled with IT and TOF-MS are highlighted

    N-(2-Chloro­benzo­yl)-N′-(3-pyrid­yl)thio­urea

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    In the mol­ecule of the title compound, C13H10ClN3OS, the dihedral angles between the plane through the thio­urea group and the pyridine and benzene rings are 53.08 (3) and 87.12 (3)°, respectively. The mol­ecules are linked by inter­molecular N—H⋯N hydrogen-bonding inter­actions to form a supra­molecular chain structure along the a axis. An intra­mol­ecular N—H⋯O hydrogen bond is also present

    FSD-C10, a Fasudil derivative, promotes neuroregeneration through indirect and direct mechanisms.

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    FSD-C10, a Fasudil derivative, was shown to reduce severity of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), through the modulation of the immune response and induction of neuroprotective molecules in the central nervous system (CNS). However, whether FSD-C10 can promote neuroregeneration remains unknown. In this study, we further analyzed the effect of FSD-C10 on neuroprotection and remyelination. FSD-C10-treated mice showed a longer, thicker and more intense MAP2 and synaptophysin positive signal in the CNS, with significantly fewer CD4(+) T cells, macrophages and microglia. Importantly, the CNS of FSD-C10-treated mice showed a shift of activated macrophages/microglia from the type 1 to type 2 status, elevated numbers of oligodendrocyte precursor cells (OPCs) and oligodendrocytes, and increased levels of neurotrophic factors NT-3, GDNF and BDNF. FSD-C10-treated microglia significantly inhibited Th1/Th17 cell differentiation and increased the number of IL-10(+) CD4(+) T cells, and the conditioned medium from FSD-C10-treated microglia promoted OPC survival and oligodendrocyte maturation. Addition of FSD-C10 directly promoted remyelination in a chemical-induced demyelination model on organotypic slice culture, in a BDNF-dependent manner. Together, these findings demonstrate that FSD-C10 promotes neural repair through mechanisms that involved both immunomodulation and induction of neurotrophic factors

    Validation of an LC-MS/MS Method to Quantify the New TRPC6 Inhibitor SH045 (Larixyl N-methylcarbamate) and Its Application in an Exploratory Pharmacokinetic Study in Mice

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    TRPC6 (transient receptor potential cation channels; canonical subfamily C, member 6) is widespread localized in mammalian tissues like kidney and lung and associated with progressive proteinuria and pathophysiological pulmonary alterations, e.g., reperfusion edema or lung fibrosis. However, the understanding of TRPC6 channelopathies is still at the beginning stages. Recently, by chemical diversification of (+)-larixol originating from Larix decidua resin traditionally used for inhalation, its methylcarbamate congener, named SH045, was obtained and identified in functional assays as a highly potent, subtype-selective inhibitor of TRPC6. To pave the way for use of SH045 in animal disease models, this study aimed at developing a capable bioanalytical method and to provide exploratory pharmacokinetic data for this promising derivative. According to international guidelines, a robust and selective LC-MS/MS method based on MRM detection in positive ion mode was established and validated for quantification of SH045 in mice plasma, whereby linearity and accuracy were demonstrated for the range of 2–1600 ng/mL. Applying this method, the plasma concentration time course of SH045 following single intraperitoneal administration (20 mg/kg body weight) revealed a short half-life of 1.3 h. However, the pharmacological profile of SH045 is promising, as five hours after administration, plasma levels still remained sufficiently higher than published low nanomolar IC50 values. Summarizing, the LC-MS/MS method and exploratory pharmacokinetic data provide essential prerequisites for experimental pharmacological TRPC6 modulation and translational treatment of TRPC6 channelopathies

    Analgesic effect of auricular point acupressure for acute pain in patients with dementia: Study protocol for a randomized controlled trial

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    Background: Common and frequent as acute pain is, it is often underestimated and undertreated in older people with dementia in nursing homes and inadequate pain management remains an issue. Methods: The study is designed to be a randomized, sham-controlled trial and is underway in nursing homes located in China. A total of 206 dementia patients are being recruited from nursing homes in Yinchuan, China. They are randomly allocated to an intervention or a controlled group in a 1:1 ratio. The intervention group will be treated with true APP therapy, while the other group will receive APP at sham point stimulation therapy. The patients will be assessed at baseline (T0), at 5 min during performing the intervention (T1), and at 5 min after completion of the intervention (T2). The primary outcome is the level of pain relief at T1 and T2. Physiological parameters, side effects and additional use of analgesics during the procedure, satisfaction from caregivers, and acceptance of patients are evaluated as secondary outcomes. Discussion: The results of this study are expected to verify the analgesic effect of APP for acute pain in patients with mild dementia in nursing homes. It has the potential to prompt APP therapy to be implemented widely in dementia patients with acute pain in nursing homes. Trial registration: Chinese Clinical Trial Registry ChiCTR2100047932. Registered on 27 June 2021. Currently, patient recruitment is ongoing. Recruitment is expected to take place from December 2020 to December 2021

    Strong southward transport events due to typhoons in the Taiwan Strait

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    Transport through the Taiwan Strait under the influence of five typhoons was investigated using both buoy observations and numerical model simulations during the period of 27 August to 5 October 2005. The results show that the effects of typhoons on the Taiwan Strait and its adjacent sea area caused strong southward transport events in the Taiwan Strait, which changed the direction of the Taiwan Strait northward transport temporarily. Typhoon-generated local wind stress and/or along-strait water level gradient were the direct driving factors in these southward transport events. The numerical results show that the Coriolis force made a negative contribution to these events and the contribution of the along-strait momentum gradient was insignificant.China Postdoctoral Science Foundation [20070420745]; Science Foundation of Fujian Province [2009J01223]; National High-Tech Research and Development [2006AA09A302-6

    Recurrent DNMT3A R882 Mutations in Chinese Patients with Acute Myeloid Leukemia and Myelodysplastic Syndrome

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    Somatic mutations of DNMT3A gene have recently been reported in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). We examined the entire coding sequences of DNMT3A gene by high-resolution melting analysis and sequencing in Chinese patients with myeloid malignancies. R882 mutations were found in 12/182 AML and in 4/51 MDS, but not in either 79 chronic myeloid leukemia (CML), or 57 myeloproliferative neoplasms (MPNs), or 4 chronic monomyelocytic leukemia. No other DNMT3A mutations were detected in all patients. R882 mutations were associated with old age and more frequently present in monoblastic leukemia (M4 and M5, 7/52) compared to other subtypes (5/130). Furthermore, 14/16 (86.6%) R882 mutations were observed in patients with normal karyotypes. The overall survival of mutated MDS patients was shorter than those without mutation (median 9 and 25 months, respectively). We conclude that DNMT3A R882 mutations are recurrent molecular aberrations in AML and MDS, and may be an adverse prognostic event in MDS
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