3,943 research outputs found
A Routing Path Construction Method for Key Dissemination Messages in Sensor Networks
Authentication is an important security mechanism for detecting forged messages in a sensor network. Each cluster head (CH) in dynamic key distribution schemes forwards a key dissemination message that contains encrypted authentication keys within its cluster to next-hop nodes for the purpose of authentication. The forwarding path of the key dissemination message strongly affects the number of nodes to which the authentication keys in the message are actually distributed. We propose a routing method for the key dissemination messages to increase the number of nodes that obtain the authentication keys. In the proposed method, each node selects next-hop nodes to which the key dissemination message will be forwarded based on secret key indexes, the distance to the sink node, and the energy consumption of its neighbor nodes. The experimental results show that the proposed method can increase by 50–70% the number of nodes to which authentication keys in each cluster are distributed compared to geographic and energy-aware routing (GEAR). In addition, the proposed method can detect false reports earlier by using the distributed authentication keys, and it consumes less energy than GEAR when the false traffic ratio (FTR) is ≥10%
Activation of two types of brain glutamate dehydrogenase isoproteins by gabapentin
AbstractThe stimulatory effects of gabapentin on the activities of two types of glutamate dehydrogenase (GDH) isoproteins homogeneously purified from bovine brain have been studied at various conditions. When the effects of different gabapentin concentrations on GDH activities were studied in the direction of reductive amination of 2-oxoglutarate with NADPH as a coenzyme, a marked activation was observed for both isoproteins, whereas both isoproteins showed activation to a lesser extent with NADH as a coenzyme. Stimulatory effects of gabapentin on GDH activities in the direction of the oxidative deamination of glutamate were also observed, but to a much lesser extent than reductive amination. There were big differences between the two GDH isoproteins in their sensitivity to the action of gabapentin. The largest activation was observed with GDH II when NADPH was used as a coenzyme. Half-maximal stimulation was reached at around 1.5 mM. Gabapentin relieved the inhibition of GDH isoproteins by GTP and this resulted in an increase in the apparent activation by gabapentin in the presence of GTP. 2-Oxoglutarate was found to give rise to high substrate inhibition and gabapentin reduced the substrate inhibition in the presence of 0.2 mM NADH. Since there are neurodegenerative disorders in which GDH activity is decreased, the therapeutic modulation of the activity of this enzyme may be clinically useful
The Evaluation of the Body Weight Lowering Effects of Herbal Extract THI on Exercising Healthy Overweight Humans: A Randomized Double-Blind, Placebo-Controlled Trial
We investigated the effects of herbal extracts, a mixture of Scutellariae Radix and Platycodi Radix containing the active ingredients Baicalin and Saponin (target herbal ingredient (THI)), on lowering body weight. The present study was a prospective, randomized, double-blind, and placebo-controlled trial carried out at the outpatient department of a hospital over a period of 2 months. Group 1 patients (n=30) received THI, and group 2 patients (n=23) received placebo three times a day before meals. Weight, waist circumference, BMI, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and glucose were measured at baseline and again at the 2nd month. For safety evaluation, various hematological and biochemical parameters were assessed. Values of mean change of weight in the THI-treated group were −1.16±1.41 kg and in the placebo-treated group were −0.24±1.70 kg, respectively. The difference in mean change of weight in the THI-treated group compared with that in the placebo-treated group was statistically significant (P<0.05). The incidence of subjective and objective adverse drug reactions was insignificant (P>0.05). THI was statistically significant in its effectiveness on the weight loss
An Extension of the Cochran Q test
The familiar x 2 test is ordinarily used to compare percentage distributions of categorical data for two or more independent samples. A more accurate com parison of the percentages is sometimes obtained if the samples consist of matched individuals. The NcNemar test is generally used when comparing only two related samples. Where there are three or more samples the Cochran Q test is used. Both of these tests apply only to the case of dichotomized responses. This thesis extends the Cochran Q test to the case where the responses are multinomial. A generalized statistic corresponding to Cochran\u27s result is obtained. As in Cochran\u27s case this statistic has asymptotically a x 2 distribution with degrees of freedom equal to one less than the number of samples
Identification of ERBB Pathway-Activated Cells in Triple-Negative Breast Cancer
Intratumor heterogeneity within a single tumor mass is one of the hallmarks of malignancy and has been reported in various tumor types. The molecular characterization of intratumor heterogeneity in breast cancer is a significant challenge for effective treatment. Using single-cell RNA sequencing (RNA-seq) data from a public resource, an ERBB pathway activated triple-negative cell population was identified. The differential expression of three subtyping marker genes (ERBB2, ESR1, and PGR) was not changed in the bulk RNA-seq data, but the single-cell transcriptomes showed intratumor heterogeneity. This result shows that ERBB signaling is activated using an indirect route and that the molecular subtype is changed on a single-cell level. Our data propose a different view on breast cancer subtypes, clarifying much confusion in this field and contributing to precision medicine
Control of chicken CR1 retrotransposons is independent of Dicer-mediated RNA interference pathway
BACKGROUND: Dicer is an RNase III-ribonuclease that initiates the formation of small interfering
RNAs as a defence against genomic parasites such as retrotransposons. Despite intensive
characterization in mammalian species, the biological functions of Dicer in controlling
retrotransposable elements of the non-mammalian vertebrate are poorly understood. In this
report, we examine the role of chicken Dicer in controlling the activity of chicken CR1
retrotransposable elements in a chicken-human hybrid DT40 cell line employing a conditional lossof-
Dicer function.
RESULTS: Retrotransposition is detrimental to host genome stability and thus eukaryotic cells have
developed mechanisms to limit the expansion of retrotransposons by Dicer-mediated RNAi
silencing pathways. However, the mechanisms that control the activity and copy numbers of
transposable elements in chicken remain unclear. Here, we describe how the loss of Dicer in
chicken cells does not reactivate endogenous chicken CR1 retrotransposons with impaired RNAi
machinery, suggesting that the control of chicken CR1 is independent of Dicer-induced RNAi
silencing. In contrast, upon introduction of a functionally active human L1 retrotransposable
element that contains an active 5' UTR promoter, the Dicer-deficient chicken cells show a strong
increase in the accumulation of human L1 transcripts and retrotransposition activity, highlighting a
major difference between chicken CR1 and other mammalian L1 retrotransposons.
CONCLUSION: Our data provide evidence that chicken CR1 retrotransposons, unlike their
mammalian L1 counterparts, do not undergo retrotransposition because most CR1
retrotransposons are truncated or mutated at their 5'UTR promoters and thus are not subjected
to Dicer-mediated RNAi-silencing control
Weight Gain and its Correlates among Breast Cancer Survivors
SummaryPurposeWeight gain after diagnosis of breast cancer is a profound issue that may negatively impact cancer prognosis. However, most existing research on weight change has been conducted in Western countries. In addition, several factors related to weight gain have been reported; however, the evidence is inconsistent. The purpose of this study was to examine weight gain and its correlates among Korean breast cancer survivors.MethodsA total of 132 female breast cancer survivors were recruited from one university hospital in South Korea. Participants completed anthropometric measurements (i.e., body weight, height) and a self-reported questionnaire, including the International Physical Activity Questionnaire Short Form and Mini Dietary Assessment.ResultsThe mean weight change was −0.09 kg (SD = 4.28). Only 27 women (19.7%) gained more than 5% of their weight at diagnosis, 59.1% maintained weight, and 21.2% lost weight. In multivariate logistic regression analysis, significant correlates of weight gain were younger age, obesity at diagnosis, duration of more than 36 months since diagnosis, and low diet quality.ConclusionYounger women, women who were obese at diagnosis, women with more than 36 months since diagnosis, or women who showed lower diet quality should be considered at high-risk for weight gain. Findings from our study suggest that optimal weight management strategies should be developed using ethnically- or culturally-appropriate approaches
Effect of tDCS on aberrant functional network connectivity in refractory hallucinatory schizophrenia: A pilot study
The Role of Sphingosine Kinase 1/Sphingosine-1-Phosphate Pathway in the Myogenic Tone of Posterior Cerebral Arteries
AIMS: The goal of the current study was to determine whether the sphingosine kinase 1 (SK1)/sphingosine-1-phosphate (S1P) pathway is involved in myogenic vasoconstriction under normal physiological conditions. In the present study, we assessed whether endogenous S1P generated by pressure participates in myogenic vasoconstriction and which signaling pathways are involved in SK1/S1P-induced myogenic response under normal physiological conditions. METHODS AND RESULTS: We measured pressure-induced myogenic response, Ca(2+) concentration, and 20 kDa myosin light chain phosphorylation (MLC(20)) in rabbit posterior cerebral arteries (PCAs). SK1 was expressed and activated by elevated transmural pressure in rabbit PCAs. Translocation of SK1 by pressure elevation was blocked in the absence of external Ca(2+) and in the presence of mechanosensitive ion channel and voltage-sensitive Ca(2+) channel blockers. Pressure-induced myogenic tone was inhibited in rabbit PCAs treated with sphingosine kinase inhibitor (SKI), but was augmented by treatment with NaF, which is an inhibitor of sphingosine-1-phosphate phosphohydrolase. Exogenous S1P further augmented pressure-induced myogenic responses. Pressure induced an increase in Ca(2+) concentration leading to the development of myogenic tone, which was inhibited by SKI. Exogenous S1P further increased the pressure-induced increased Ca(2+) concentration and myogenic tone, but SKI had no effect. Pressure- and exogenous S1P-induced myogenic tone was inhibited by pre-treatment with the Rho kinase inhibitor and NADPH oxidase inhibitors. Pressure- and exogenous S1P-induced myogenic tone were inhibited by pre-treatment with S1P receptor blockers, W146 (S1P1), JTE013 (S1P2), and CAY10444 (S1P3). MLC(20) phosphorylation was increased when the transmural pressure was raised from 40 to 80 mmHg and exogenous S1P further increased MLC(20) phosphorylation. The pressure-induced increase of MLC(20) phosphorylation was inhibited by pre-treatment of arteries with SKI. CONCLUSIONS: Our results suggest that the SK1/S1P pathway may play an important role in pressure-induced myogenic responses in rabbit PCAs under normal physiological conditions
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