Collapsin response mediator protein-2(CRMP2) proteolysis mediated by calpain after traumatic brain injury (TBI) may be a possible inhibiting factor for posttraumatic neurite regeneration. We examined ...the hypothesis that lipid peroxidation involves in triggering calpain-mediated CRMP2 proteolysis and whether propofol would attenuate CRMP2 degradation and apoptosis after TBI. Propofol postconditioning could alleviate calpain-mediated CRMP2 proteolysis and provide neuroprotective effects after moderate TBI through counteracting lipid peroxidation and reducing calpain activity.
This paper describes an INtrusion-tolerant routing protocol for wireless SEnsor NetworkS (INSENS). INSENS securely and efficiently constructs tree-structured routing for wireless sensor networks ...(WSNs). The key objective of an INSENS network is to tolerate damage caused by an intruder who has compromised deployed sensor nodes and is intent on injecting, modifying, or blocking packets. To limit or localize the damage caused by such an intruder, INSENS incorporates distributed lightweight security mechanisms, including efficient one-way hash chains and nested keyed message authentication codes that defend against wormhole attacks, as well as multipath routing. Adapting to WSN characteristics, the design of INSENS also pushes complexity away from resource-poor sensor nodes towards resource-rich base stations. An enhanced single-phase version of INSENS scales to large networks, integrates bidirectional verification to defend against rushing attacks, accommodates multipath routing to multiple base stations, enables secure joining/leaving, and incorporates a novel pairwise key setup scheme based on transitory global keys that is more resilient than LEAP. Simulation results are presented to demonstrate and assess the tolerance of INSENS to various attacks launched by an adversary. A prototype implementation of INSENS over a network of MICA2 motes is presented to evaluate the cost incurred.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
1 Department of Biological Sciences, National University of Singapore, Singapore; 2 Neuroscience Research Institute, Peking University and Department of Neurobiology, Peking University Health Science ...Center, Beijing, China; and 3 The University Scholars Programme, National University of Singapore, Singapore
Submitted 17 November 2004;
accepted in final form 12 January 2006
The modulatory effects of nitric oxide (NO) on voltage-dependent K + channels are intricate. In our present study, the augmentation and reduction of K + currents by NO donor S -nitro- N -acetylpenicillamine (SNAP) and pure dissolved NO was observed in dissociated neurons from mice neocortex with both whole cell and cell-attached patch clamp. By using a specific electrochemical sensor, the critical concentrations of NO that increased or reduced the channel activities were accurately quantified. Low concentrations of SNAP (20 µM) or NO solution (0.1 µM) enhanced whole cell delayed rectifier K + -current ( I K ) and left the fast inactivating A current ( I A ) unchanged. However, high concentrations of SNAP (100 µM) and NO (0.5 µM) reduced both I K and I A currents. In cell-attached experiments, a significant increase in channel open probability (NP 0 ) was observed when using low concentrations of SNAP or NO. High concentrations of SNAP or NO dramatically decreased NP 0 . The increase in channel activities by low concentrations of SNAP was abolished in the presence of either inhibitors of soluble guaylate cyclase or inhibitors of cGMP-dependent protein kinase G, suggesting a link to the NO-cGMP signaling cascade. The reduction of channel activities by high concentrations of SNAP was reversed by the reducing agent dithiothreitol, implying a redox reaction mechanism. Thus both NO-cGMP signaling and a redox mechanism are involved in the modulation of I K channel activity for neuron excitability.
Address for reprint requests and other correspondence: F.-S. Sheu, Dept. of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore (E-mail: dbssfs{at}nus.edu.sg )
•Angiotensin-1 receptor and angiotensin-converting enzyme (ACE) polymorphisms were studied.•Aldosterone synthase polymorphisms were studied.•Angiotensin type-1 receptor (A1166C) polymorphism was ...associated with hypotension.•A1166C polymorphism did not increase vasopressor or adverse maternal/fetal outcomes.•ACE and aldosterone synthase polymorphisms were not associated with hypotension.
Unless prevented, hypotension occurs in up to 80% of normotensive women undergoing spinal anaesthesia for caesarean delivery. Renin-angiotensin-aldosterone system genetic polymorphisms have been associated with hypertensive disease, but few studies investigated effects on blood pressure regulation under spinal anaesthesia. We postulated that these polymorphisms increased vasodilation and maternal hypotension during spinal anaesthesia.
A retrospective secondary analysis of data from four prospective trials with similar inclusion/exclusion criteria evaluating phenylephrine/ephedrine delivery systems during spinal anaesthesia for elective caesarean delivery. Angiotensin type-1 receptor (AT1R) (A1166C), angiotensin-converting enzyme (ACE) (I/D), and aldosterone synthase CYP11B2 (C344T) polymorphisms were identified from stored specimens. The associations between the polymorphisms and hypotension (systolic blood pressure <80% of baseline), and vasopressor use, were determined by univariable and multivariable regression.
Of 556 patients, 378 (68.0%) had hypotension. The AC/CC genotypes of AT1R (A1166C) were associated with hypotension by univariable analysis (OR 2.70, 95% CI 1.38 to 5.28, P=0.004) and multivariable analysis (OR 3.65, 95% CI 1.68 to 7.94, P=0.004) after adjustment for age, race, intravenous fluid volume, and block height. No difference in vasopressor use or adverse maternal or fetal outcomes were noted. Baseline characteristics were similar, with the exception of higher baseline blood pressure, block height, and intravenous fluid volume in the hypotensive group. There was no significant association between ACE and CYP11B2 polymorphisms and hypotension.
AC/CC genotypes of AT1R (A1166C) polymorphism were associated with maternal hypotension under spinal anaesthesia for caesarean delivery. An association with cardiovascular indices and high-risk parturients should be examined.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The dry etching characteristics of indium-tin-oxide (ITO) films deposited on plastic substrates were studied using Ar/CH4 magnetized inductively coupled plasmas (MICP). When conventional inductively ...coupled plasmas (ICP) were used, the etch rates of ITO films were generally low. However, by using both the multidipole magnets and the axial electromagnets around the chamber wall of ICP, high ITO etch rates >250 nm/min could be obtained at 90% Ar/10% CH4 with the etch selectivity over photoresist higher than that of the ICP. Atomic force microscopy (AFM) measured as a function of Ar/CH4 showed smoother etched ITO surfaces for most of the etch conditions except for high CH4 conditions such as 70% Ar/30% CH4 which generate hydrocarbon polymer on the etched ITO surface. The surface composition characterized using x-ray photoelectron spectroscopy (XPS) showed preferential losses of ITO components depending on the etch gas composition.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Exposure of neonatal rats to > or = 95% O2 for 2 wk, a widely used model of oxidant/antioxidant interactions in neonatal lung injury, results in arrested lung growth without the dysplastic lesions ...observed in chronic human neonatal lung injury. To determine whether dysplastic lung cell growth would be seen at lesser O2 concentrations, we exposed newborn rats to either 95% O2 for 1 wk followed by 60% O2 for 1 wk, or to 60% O2 for 2 wk. Exposure to 95% O2 for 1 wk profoundly inhibited lung DNA synthesis. Recovery of synthesis did not occur during the 2nd wk in 60% O2, nor were areas of dysplastic growth evident in lung tissue. In contrast, a continuous 2-wk exposure to 60% O2 resulted in a slight increase in lung weight with a significant reduction in lung volume over a range of inflation pressures. Also seen was an overall, but inhomogeneous, reduction in lung cell DNA synthesis. A preliminary analysis of affected cell types suggested that inhibition of DNA synthesis affected endothelial cells more than interstitial cells, whereas DNA synthesis increased in type II pneumocytes. Areas of reduced DNA synthesis were interspersed with patchy areas of parenchymal thickening and active DNA synthesis. These areas of parenchymal thickening, but not other areas, had increased immunoreactive IGF-I and the type I IGF receptor. These data are consistent with a direct effect of O2 on growth factor and growth factor receptor expression in causing dysplastic lung cell growth in chronic neonatal lung injury.
...smell and taste loss are common complaints among patients with covid-19, with an estimated 50% of patients reporting these symptoms.1 This is thought to occur due to conductive barriers and nerve ...damage from the extensive inflammation in covid-19 infection.2345 The recovery of smell and taste is very much a gradual process for some. Using a mathematical technique known as cure modelling to project the plateaus of smell and taste recovery across 18 studies, we found that self-reported smell loss may persist in 5.6% of patients, while 4.4% may not recover their self-reported sense of taste (for some this reflects loss of flavour perception, a function of olfaction, while in others it may reflect true gustatory dysfunction).7 With more than 550 million confirmed covid-19 cases as of July 2022, this means that potentially 15 million and 12 million patients may experience long term smell and taste impairments, respectively, based on our modelling. Besides a quantitative impairment in smell, a sizeable proportion of patients also report qualitative smell impairment following covid-19 infection, manifesting as distortion of odour (known as parosmia) or a perception of smell in the absence of an odour (known as phantosmia).8 These patients often struggle to tolerate everyday smells and become increasingly withdrawn. According to one patient, she was not particularly concerned by the smell loss initially because she saw it as something temporary that many patients had to deal with.
Amoxicillin is often implemented in Helicobacter pylori treatment protocols. Since 1996, we have isolated seven H. pylori strains exhibiting high-level amoxicillin resistance.
PDF
