19 research outputs found

    Resonant Varifocal Micromirror with Piezoresistive Focus Sensor

    No full text
    This paper reports a microelectromechanical systems (MEMS) resonant varifocal mirror integrated with piezoresistive focus sensor. The varifocal mirror is driven electrostatically at a resonant frequency of a mirror plate to obtain the wide scanning range of a focal length. A piezoresistor is used to monitor the focal length of the varifocal mirror. The device is made of a silicon-on-insulator (SOI) wafer and a glass wafer. A mirror plate and a counter electrode are fabricated by a top silicon layer of the SOI wafer and on the glass wafer, respectively. The piezoresistor is fabricated by ion implantation on a supporting beam of the mirror plate. The stress variation of the beam, which is detected by the piezoresistor, correspond the focal length of the varifocal mirror. The focus length varies from āˆ’41 to 35 mm at the resonant frequency of 9.5 kHz. The focal length of the varifocal mirror is monitored by the piezoresistor in real time

    NMDA Receptor GluN2B (GluRĪµ2/NR2B) Subunit Is Crucial for Channel Function, Postsynaptic Macromolecular Organization, and Actin Cytoskeleton at Hippocampal CA3 Synapses

    Get PDF
    GluN2B (GluRĪµ2/NR2B) subunit is involved in synapse development, synaptic plasticity, and cognitive function. However, its roles in synaptic expression and function of NMDA receptors (NMDARs) in the brain remain mostly unknown because of the neonatal lethality of global knock-out mice. To address this, we generated conditional knock-out mice, in which GluN2B was ablated exclusively in hippocampal CA3 pyramidal cells. By immunohistochemistry, GluN2B disappeared and GluN1 (GluRĪ¶1/NR1) was moderately reduced, whereas GluN2A (GluRĪµ1/NR2A) and postsynaptic density-95 (PSD-95) were unaltered in the mutant CA3. This was consistent with protein contents in the CA3 crude fraction: 9.6% of control level for GluN2B, 47.7% for GluN1, 90.6% for GluN2A, and 98.0% for PSD-95. Despite the remaining NMDARs, NMDAR-mediated currents and long-term potentiation were virtually lost at various CA3 synapses. Then, we compared synaptic NMDARs by postembedding immunogold electron microscopy and immunoblot using the PSD fraction. In the mutant CA3, GluN1 was severely reduced in both immunogold (20.6-23.6%) and immunoblot (24.6%), whereas GluN2A and PSD-95 were unchanged in immunogold but markedly reduced in the PSD fraction (51.4 and 36.5%, respectively), indicating increased detergent solubility of PSD molecules. No such increased solubility was observed for GluN2B in the CA3 of GluN2A-knock-out mice. Furthermore, significant decreases were found in the ratio of filamentous to globular actin (49.5%) and in the density of dendritic spines (76.2%). These findings suggest that GluN2B is critically involved in NMDAR channel function, organization of postsynaptic macromolecular complexes, formation or maintenance of dendritic spines, and regulation of the actin cytoskeleton

    Pantethine, a derivative of vitamin B(5) used as a nutritional supplement, favorably alters low-density lipoprotein cholesterol metabolism in low- to moderate-cardiovascular risk North American subjects: a triple-blinded placebo and diet-controlled investigation.

    No full text
    Safety and efficacy of a biologically active derivative of vitamin B(5) (pantethine) on total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) metabolism was studied in North American subjects at conventional low to moderate cardiovascular disease (CVD) risk. A total of 120 subjects initiated a therapeutic lifestyle change (TLC) diet 4 weeks before randomization (baseline) and maintained the diet throughout a 16-week study period; at baseline, subjects were randomized in a triple-blinded manner to either pantethine (600 mg/d, baseline to week 8, and 900 mg/d, weeks 9-16) or identically labeled, nonbiologically active placebo (n = 60 per group). We hypothesized that pantethine would lower TC and low-density lipoprotein in low-CVD-risk North American subjects in a similar manner as reported in high-CVD-risk subjects studied mainly in Italy and Japan. While sustaining a TLC diet and in comparison with placebo, pantethine demonstrated significant (P \u3c .005) and sustained reductions (from baseline to week 16) in TC (6 mg/dL, 0.16 mmol/L, 3%), LDL-C (4 mg/dL, 0.10 mmol/L, 4%), and apolipoprotein B (4 mg/dL, 0.04 g/L, 5%). Our data suggest that pantethine supplementation for 16 weeks (600 mg/d for weeks 1-8 then 900 mg/d for weeks 9-16) is safe and significantly lowers TC and LDL-C over and above the effect of TLC diet alone. Although the absolute magnitude of these effects was small in these low- to moderate-risk North Americans (4-6 mg/dL), the results are noteworthy as prior studies have shown that, for each 1 mg/dL (0.026 mmol/L) reduction in LDL-C, there is a concomitant 1% reduction in overall future CVD risk

    Pantethine, a derivative of vitamin B5, favorably alters total, LDL and non-HDL cholesterol in low to moderate cardiovascular risk subjects eligible for statin therapy: a triple-blinded placebo and diet-controlled investigation.

    No full text
    High serum concentration of low-density lipoprotein cholesterol (LDL-C) is a major risk factor for coronary heart disease. The efficacy of pantethine treatment on cardiovascular risk markers was investigated in a randomized, triple-blinded, placebo-controlled study, in a low to moderate cardiovascular disease (CVD) risk North American population eligible for statin therapy, using the National Cholesterol Education Program (NCEP) guidelines. A total of 32 subjects were randomized to pantethine (600 mg/day from weeks 1 to 8 and 900 mg/day from weeks 9 to 16) or placebo. Compared with placebo, the participants on pantethine showed a significant decrease in total cholesterol at 16 weeks (P=0.040) and LDL-C at 8 and 16 weeks (P=0.020 and P=0.006, respectively), and decreasing trends in non-high-density lipoprotein cholesterol at week 8 and week 12 (P=0.102 and P=0.145, respectively) that reached significance by week 16 (P=0.042). An 11% decrease in LDL-C from baseline was seen in participants on pantethine, at weeks 4, 8, 12, and 16, while participants on placebo showed a 3% increase at week 16. This decrease was significant between groups at weeks 8 (P=0.027) and 16 (P=0.010). The homocysteine levels for both groups did not change significantly from baseline to week 16. Coenzyme Q10 significantly increased from baseline to week 4 and remained elevated until week 16, in both the pantethine and placebo groups. After 16 weeks, the participants on placebo did not show significant improvement in any CVD risk end points. This study confirms that pantethine lowers cardiovascular risk markers in low to moderate CVD risk participants eligible for statins according to NCEP guidelines
    corecore