1,421 research outputs found
A Novel Three-Point Modulation Technique for Fractional-N Frequency Synthesizer Applications
This paper presents a novel three-point modulation technique for fractional-N frequency synthesizer applications. Convention modulated fractional-N frequency synthesizers suffer from quantization noise, which degrades not only the phase noise performance but also the modulation quality. To solve this problem, this work proposes a three-point modulation technique, which not only cancels the quantization noise, but also markedly boosts the channel switching speed. Measurements reveal that the implemented 2.4 GHz fractional-N frequency synthesizer using three-point modulation can achieve a 2.5 Mbps GFSK data rate with an FSK error rate of only 1.4 %. The phase noise is approximately -98 dBc/Hz at a frequency offset of 100 kHz. The channel switching time is only 1.1 Îźs with a frequency step of 80 MHz. Comparing with conventional two-point modulation, the proposed three-point modulation greatly improves the FSK error rate, phase noise and channel switching time by about 10 %, 30 dB and 126 Îźs, respectively
Effect of Auricular Acupressure on Peri- and Early Postmenopausal Women with Anxiety: A Double-Blinded, Randomized, and Controlled Pilot Study
We tested effects of auricular acupressure on peri- and early postmenopausal women with anxiety (PPWA). Fifty PPWA were randomly assigned to the auricular acupressure group (AG) or the sham group (SG). After 3 meals and before sleep every day for 4 weeks, the AG received auricular acupressure on the bilateral ear shenmen and subcortex points for 3âmin per point on alternating ears. The SG received sham auricular acupressure. The Alprazolam was reduced from 0.5âmg/day at baseline to 0.3âmg/day 4 weeks after auricular acupressure (4âW) in the AG (P < .05) whereas maintained at 0.5âmg/day in the SG (P > .05). The Zolpidem was reduced from 3.0âmg/day at baseline to 1.5âmg/day at 4âW (P < .05) whereas was reduced from 2.4âmg/day to 1.9âmg/day at 4âW in the SG (P > .05), thus, significant tapering medication, suggesting auricular acupressure is helpful to PPWA
Using LC-MS with de novo software to fully characterize the multiple methylations of lysine residues in a recombinant fragment of an outer membrane protein from a virulent strain of Rickettsia prowazekii
The outer membrane protein B (OmpB) of the typhus group rickettsiae is an immunodominant antigen and has been shown to provide protection against typhus in animal models. Consequently, OmpB is currently being considered as a potential rickettsiae vaccine candidate to be used in humans. The OmpB from virulent strains are heavily methylated while the attenuated strains are hypomethylated. Western blot analysis of partially digested OmpB revealed that one of the reactive fragments was located at the N-terminus (fragment A, aa 33â272). Recently, we have over expressed, purified, and chemically methylated the recombinant fragment A from Rickettsia prowazekii (Ap). The methylated Ap was thoroughly characterized by LC/MS/MS on the ProteomeX workstation. The protein sequence of Ap with and without methylation was 87.7% and 100% identified, respectively. This high sequence coverage enabled us to determine the sites and extent of methylation on the lysine residues in Ap. All the lysine residues except the C-terminus lysine were either mono-, di- or tri-methylated. In addition, carbamylation on the N-terminus glycine was identified using a combination of denovo sequencing (DeNovoX) and the pattern recognition (SALSA) program with accurate mass measurement. We demonstrated that the use of peptide identification (SEQUEST) in combination with SALSA and denovo sequencing provided a useful means to characterize the sequence and posttranslational modifications of given proteins
Nutrient deprivation induces the Warburg effect through ROS/AMPK-dependent activation of pyruvate dehydrogenase kinase
AbstractThe Warburg effect is known to be crucial for cancer cells to acquire energy. Nutrient deficiencies are an important phenomenon in solid tumors, but the effect on cancer cell metabolism is not yet clear. In this study, we demonstrate that starvation of HeLa cells by incubation with Hank's buffered salt solution (HBSS) induced cell apoptosis, which was accompanied by the induction of reactive oxygen species (ROS) production and AMP-activated protein kinase (AMPK) phosphorylation. Notably, HBSS starvation increased lactate production, cytoplasmic pyruvate content and decreased oxygen consumption, but failed to change the lactate dehydrogenase (LDH) activity or the glucose uptake. We found that HBSS starvation rapidly induced pyruvate dehydrogenase kinase (PDK) activation and pyruvate dehydrogenase (PDH) phosphorylation, both of which were inhibited by compound C (an AMPK inhibitor), NAC (a ROS scavenger), and the dominant negative mutant of AMPK. Our data further revealed the involvement of ROS production in AMPK activation. Moreover, DCA (a PDK inhibitor), NAC, and compound C all significantly decreased HBSS starvation-induced lactate production accompanied by enhancement of HBSS starvation-induced cell apoptosis. Not only in HeLa cells, HBSS-induced lactate production and PDH phosphorylation were also observed in CL1.5, A431 and human umbilical vein endothelial cells. Taken together, we for the first time demonstrated that a low-nutrient condition drives cancer cells to utilize glycolysis to produce ATP, and this increases the Warburg effect through a novel mechanism involving ROS/AMPK-dependent activation of PDK. Such an event contributes to protecting cells from apoptosis upon nutrient deprivation
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Investigations of urethral sphincter activity in mice with bladder hyperalgesia before and after drug administration of gabapentin.
PurposeThis study investigated the effect of gabapentin on lower urinary tract dysfunction focusing on urethral activities and cystitis-induced hyperalgesia in a mouse model of painful bladder syndrome/interstitial cystitis (PBS/IC). The electromyography (EMG) of external urethral sphincter (EUS) was difficult to obtain, but contained useful information to examine the drug effect in mice.MethodsFemale C57BL/6J mice were intraperitoneally (ip) administration with either saline or 200 mg/kg of cyclophosphamide (CYP) 48 h before experimental evaluation. Cystitis mice were treated with administration of gabapentin (25 or 50 mg/kg, ip). Cystometry and EUS EMG were obtained and analyzed during continuous bladder infusion. The visceral pain-related visceromotor reflex (VMR) was recorded in response to isotonic bladder distension.ResultsCystitis mice showed shorter inter-contraction intervals and increased occurrence of non-voiding contractions during bladder infusion, with increased VMR during isotonic bladder distension, indicating cystitis-induced bladder hyperalgesia. Gabapentin (50 mg/kg) suppressed effects of CYP on cystometry, but not on EUS EMG activity, during bladder infusion. The effect on urodynamic recordings lasted 4 h. VMR was significantly reduced by gabapentin.ConclusionsThe present study showed that CYP-induced cystitis in mice is a model of visceral hyperalgesia affecting detrusor contractions, not urethral activations. The technique of using EUS EMG to evaluate the drug effects on urethral activities is novel and useful for future investigations. Gabapentin can be as a potential treatment for detrusor overactivity and PBS/IC
Extending the Technology Acceptance Model to Investigate Impact of Embodied Games on Learning of Xiao-zhuan()
AbstractThis research focuses on topic of e-learning of Xiao-zhuan through digital Embodied games as a brand new way of creative learning method for Xiao-zhuan. TAM, Technology Acceptance Model, is the methodology in this research. Theory of perceived playfulness is also adopted to analyze the learning of Xiao-zhuan. Subjects in this research are 45 sophomores of the Department of Chinese Literature in National Taiwan Normal University. This research adopts questionnaire survey method, then refers to studentsâ paper scores on the test. The results of this research are as follows: Firstly, âPerceived Usefulnessâ has the significant influence on âLearning Effectivenessâ and âAttitude toward Using the Embodied gamesâ. Secondly, âPerceived Ease of Useâ has the influence on âPerceived Playfulnessâ. Thirdly, âPerceived Playfulnessâ has the significant influence on âAttitude toward Using the Embodied gamesâ
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