A Voltage-Controlled Surface Acoustic Wave Oscillator based on Lithium Niobate on Sapphire Low-Loss Acoustic Delay Line.

In this work, we investigate, for the first time, a low-phase noise and wide-tuning range voltage-controlled surface acoustic wave oscillator (VCSO) based on a lithium niobate on sapphire (LNOS) low-loss acoustic delay line (ADL). The thin-film LN/SiO2 bilayer acoustic waveguide, together with the single-phase unidirectional transducer (SPUDT) design, is key to attaining low insertion loss (IL) by enhancing the energy confinement and directionality. Based on a high performance ADL with an IL of only 5.2 dB, a fractional bandwidth (FBW) of 5.38%, and a group delay of 110 ns, the VCSO is implemented by commercially available circuit components using a series-resonant topology. The LNOS ADL oscillator operates at 888 MHz, showcasing a low phase noise of -94.1 dBc/Hz at 1-kHz offset and a root-mean-square (RMS) jitter of only 30.26 fs (integrated from 12 kHz to 20 MHz) while only consuming 16 mA of supply current. Featuring a wide frequency tuning range of 6,630 ppm, the proposed VCSO is a promising low-noise, low-power, high-frequency timing device for emerging applications.

A Filter-Free Third Overtone Quartz Oscillator Based on Micromachining Technology.

This work investigates an AT-cut quartz crystal oscillator (XO) operating at its enhanced third overtone thickness shear (TS) mode while suppressing the fundamental TS mode by micromachining technology. A unique quartz plate structure has been proposed to alleviate the strong resonant signal from the first mode. A finite-element method (FEM) was used to characterize the first mode suppression while improving the performance of third overtone in terms of Q -factor and motional resistance ( Rm ) of the proposed device. In measurement, the unloaded Q -factor of the fundamental TS mode is from several tens of thousands (the reference design) to only several hundred (the proposed design). Meanwhile, the unloaded Q -factor of the third overtone response for the proposed design could reach Q  âˆ¼ 95 000 with a decent Rm . The Q -factor ratio attains 170-180 between the third overtone and fundamental modes. With the feature of low Q -factor on the fundamental mode, the oscillator system could successfully oscillate at a higher frequency without the help of bandpass filtering. Finally, the closed-loop oscillation measurement is performed for the phase noise (PN) characterization. The PN performance could reach -154.5 dBc/Hz at a 1-kHz offset at the carrier frequency of  âˆ¼  60 MHz. This technique has proven its potential as a future solution of high-frequency quartz oscillator technology.

Distinct expression of Mas1-related G-protein-coupled receptor B4 in dorsal root and trigeminal ganglia--implications for altered behaviors in acid-sensing ion channel 3-deficient mice.

Mas1-related G-protein-coupled receptors (Mrgprs), comprising more than 50 distinct members, are specifically expressed in primary sensory neurons. Reflecting the diversity and specificity of stimuli they detect, Mrgprs are involved in pain, touch, and itch-related behaviors. Sensory-neuron-specific acid-sensing ion channel 3 (ASIC3) is essential for touch and inflammatory pain, but mice lacking ASIC3 have complex behavioral alterations in various modalities of pain and touch. To understand whether Mrgprs are involved in complex behavioral alterations found in ASIC3-deficient mice, we examined Mrgpr gene expression in ASIC3(-/-) mice. Only MrgprB4 expression has shown significant change. MrgprB4 expression was increased in ASIC3(-/-) dorsal root ganglia (DRG) but decreased in ASIC3(-/-) trigeminal ganglia. The distinct alterations in DRG and trigeminal ganglia imply that MrgprB4 could have multiple functions. Given that MrgprB4 is expressed in neurons that may detect gentle touch and that ASIC3(-/-) mice have altered sensitivity of mechanoreceptors for light touch, the expression change of MrgprB4 is more likely related to the altered touch behaviors of ASIC3(-/-) mice.

Drug abuse-related accidents leading to emergency department visits at two medical centers.

BACKGROUND: Drug abuse is becoming more prevalent in Taiwan, as evidenced by increasing reports of drug trafficking and drug abuse-related criminal activity, and the wide use of more contemporary illicit drugs. Consequently, drug abuse-related accidents are also expected to occur with greater frequency. However, no study has yet specifically evaluated the prevalence, pattern, and outcomes of drug abuse-related accidents among patients visiting emergency departments (EDs) in Taiwan. METHODS: We conducted an ambidirectional study with patients who visited the EDs of Taipei Veterans General Hospital (TVGH) and China Medical University Hospital (CMUH) due to drug abuse-related accidents from January 2007 through September 2009. Information on the patients' baseline characteristics and clinical outcomes was collected and analyzed. RESULTS: During the study period, a total of 166 patients visited the EDs of one of the two study hospitals due to drug abuse-related accidents. This yielded a prevalence of drug abuse of 0.1% among all patients visiting the ED due to accident and/or trauma. Fifty-six out of the 166 patients visited the ED at TVGH, most patients being between 21 and 40 years old. Opioids (41.1%) were the drugs most commonly abused by the patients, followed by benzodiazepines (32.1%). More than two-thirds of the patients (n=38, 67.9%) required hospitalization, and three patients died (5.4%). In contrast, 110 patients with drug abuse-related accidents visited the ED at CMUH during the study period. Most of these subjects had abused benzodiazepines (69.1%), were between 21 and 40 years old, and were female. Fewer than one-fifth of the patients (n=19, 17.3%) required hospitalization, with no deaths reported. There were significant between-hospital differences in terms of patient gender, drugs of choice, injury mechanisms, method and time of the ED visit, triage levels, and need for hospitalization. CONCLUSION: Although the prevalence of drug abuse-related accidents was low, and only three patient deaths were reported in this study, many patients presented to the EDs with severe effects and later required hospitalization. Better and timely management of such patients will help to minimize the adverse health impacts associated with drug abuse. Governmental agencies and all healthcare professionals should also work together to fight against the surging trend of drug abuse in Taiwan.