Low Polarization Voltage and High Sensitivity CMOS Condenser Microphone Using Stress Relaxation Design

AbstractIn this paper, a CMOS condenser microphone with high sensitivity and low polarization voltage was designed, simulated and fabricated. Due to CMOS process temperature variant and lattice defects, the poly-membrane would be invoked normal stress and gradient stress. These two residual stresses would deform the membrane and increase the membrane's rigidity. For these concerns, an interlace slots design is utilized to reduce the normal stress up to 90%, and the annealing process is applied to decrease the gradient stress. The acoustical sensitivity was increased considerably to -45dBV at 2.7V bias voltage, and, the noise level is -85dBV at 1KHz

Surface Second Harmonic Generation from Topological Dirac Semimetal PdTe2_2

Recent experiments and calculations in topological semimetals have observed anomalously strong second-order optical nonlinearity, but yet whether the enhancement also occurs at surfaces of topological semimetals in general remains an open question. In this work, we tackle this problem by measuring polarization-dependent and rotational-anisotropy optical second harmonic generation (SHG) from centrosymmetric type-II Dirac semimetal PdTe$_2$. We found the SHG to follow C$_{3v}$ surface symmetry with a time-varying intensity dictated by the oxidation kinetics of the material after its surface cleavage, indicating the surface origin of SHG. Quantitative characterization of the surface nonlinear susceptibility indicates a large out-of-plane response of PdTe$_2$ with $|\chi_{ccc}^{(2)}|$ up to 25 $\times$ 10$^{-18}$ m$^2$/V. Our results support the topological surfaces/interfaces as a new route toward applications of nonlinear optical effects with released symmetry constraints, and demonstrate SHG as a viable means to in situ study of kinetics of topological surfaces

Serum Bone Resorption Markers after Parathyroidectomy for Renal Hyperparathyroidism: Correlation Analyses for the Cross-Linked N-telopeptide of Collagen I and Tartrate-Resistant Acid Phosphatase

Patients on long-term dialysis may develop secondary hyperparathyroidism (SHPT) with increased serum concentrations of bone resorption markers such as the cross-linked N-telopeptide of type I collagen (NTX) and type-5b tartrate-resistant acid phosphatase (TRAP). When SHPT proves refractory to treatment, parathyroidectomy (PTX) may be needed. Renal patients on maintenance HD who received PTX for refractory SHPT (n=23) or who did not develop refractory SHPT (control subjects; n=25) were followed prospectively for 4 weeks. Serum intact parathyroid hormone (iPTH), NTX, TRAP, and bone alkaline phosphatase (BAP) concentrations were measured serially and correlation analyses were performed. iPTH values decreased rapidly and dramatically. BAP values increased progressively with peak increases observed at 2 weeks after surgery. NTX and TRAP values decreased concurrently and progressively through 4 weeks following PTX. A significant correlation between TRAP and NTX values was observed before PTX but not at 4 weeks after PTX. Additionally, the fractional changes in serum TRAP were larger than those in serum NTX at all times examined after PTX. Serum iPTH, TRAP, and NTX values declined rapidly following PTX for SHPT. Serum TRAP values declined to greater degrees than serum NTX values throughout the 4-week period following PTX

Ecophysiology and plant size in a tropical epiphytic fern, Asplenium nidus, in Taiwan

Recent studies indicate that, especially in epiphytes, plant size has a strong influence on the ecophysiology of individual leaves of a plant. Extensive data sets that address this phenomenon, however, are limited to a few taxa of flowering plants. It was the purpose of this study to examine numerous physiological parameters in individuals of varying sizes of Asplenium nidus, a widespread epiphytic tropical fern, in a rain forest in northeastern Taiwan. Although stomatal dimensions and frond thickness did not vary with plant size, frond stomatal densities were higher in larger plants. Frond elemental concentration did not vary with plant size for nitrogen, magnesium, phosphorus, and sodium, while the concentrations of carbon, calcium, and potassium changed with plant size, though in different ways. The osmotic concentration of liquid expressed from the fronds did not change with plant size, nor did chlorophyll concentrations and chlorophyll a/b ratio. Fronds excised from smaller plants contained more water yet lost water at lower rates in laboratory drying experiments. Although rates of net CO2 exchange of the fronds measured in situ in the field appeared to increase with plant size, this increase and other size-related differences in gas exchange parameters were not significant. Although some aspects of the ecophysiology of this epiphytic fern varied with changes in plant size, most physiological parameters did not. Thus, the results of this study lend only little support to past findings that plant size is an important consideration in ecophysiological studies of plants

Plasma fatty acids and the risk of metabolic syndrome in ethnic Chinese adults in Taiwan

<p>Abstract</p> <p>Background</p> <p>Evidence of predictive power of various fatty acids on the risk of metabolic syndrome was scanty. We evaluated the role of various fatty acids, including saturated fat, monounsaturated fat, transfat, n-6 fatty acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for the risk of the metabolic syndrome in Taiwan.</p> <p>Results</p> <p>A nested case-control study based on 1000 cases of metabolic syndrome and 1:1 matched control subjects. For saturated fat, monounsaturated fat and transfat, the higher the concentration the higher the risk for metabolic syndrome: participants in the highest quintile had a 2.22-fold (95% confidence interval [CI], 1.66 to 2.97) higher risk of metabolic syndrome. In addition, the participants in higher EPA quintiles were less likely to have the risk of metabolic syndrome (adjusted risk, 0.46 [0.34 to 0.61] for the fifth quintile). Participants in the highest risk group (low EPA and high transfat) had a 2.36-fold higher risk of metabolic syndrome (95% CI, 1.38 to 4.03), compared with those in the lowest risk group (high EPA and low transfat). For prediction power, the area under ROC curves increased from 0.926 in the baseline model to 0.928 after adding fatty acids. The net reclassification improvement for metabolic syndrome risk was substantial for saturated fat (2.1%, <it>P </it>= 0.05).</p> <p>Conclusions</p> <p>Plasma fatty acid components improved the prediction of the metabolic syndrome risk in Taiwan.</p