Perdeuterated cyanobiphenyl liquid crystals for infrared applications

Perdeuterated 4'-pentyl-4-cyanobiphenyl (D5CB) was synthesized and its physical properties evaluated and compared to those of 5CB. D5CB retains physical properties similar to those of 5CB, such as phase transition temperatures, dielectric constants, and refractive indices. An outstanding feature of D5CB is that it exhibits a much cleaner and reduced infrared absorption. Perdeuteration, therefore, extends the usable range of liquid crystals to the mid infrared by significantly reducing the absorption in the near infrared, which is essential for telecom applications

The role of digital rectal examination for diagnosis of acute appendicitis: A systematic review and meta-analysis

Background: Digital rectal examination (DRE) has been traditionally recommendedto evaluate acute appendicitis, although several reports indicate its lack of utility for this diagnosis. No metaanalysis has examined DRE for diagnosis of acute appendicitis. Objectives: To assess the role of DRE for diagnosis of acute appendicitis. Data Sources: Cochrane Library, PubMed, and SCOPUS from the earliest available date of indexing through November 23, 2014, with no language restrictions. Study Selection: Clinical studies assessing DRE as an index test for diagnosis of acute appendicitis. Data Extraction and Synthesis: Two independent reviewers extracted study data and assessed the quality, using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Bivariate random-effects models were used for the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) as point estimates with 95% confidence intervals (CI). Main Outcomes and Measures: The main outcome measure was the diagnostic performance of DRE for diagnosis of acute appendicitis. Results: We identified 19 studies with a total of 7511 patients. The pooled sensitivity and specificity were 0.49 (95% CI 0.42-0.56) and 0.61 (95% CI 0.53-0.67), respectively. The positive and negative likelihood ratios were 1.24 (95% CI 0.97-1.58) and 0.85 (95% CI 0.70-1.02), respectively. The DOR was 1.46 (0.95-2.26). Conclusion and Relevance: Acute appendicitis cannot be ruled in or out through the result of DRE. Reconsideration is needed for the traditional teaching that rectal examination should be performed routinely in all patients with suspected appendicitis

Feasibility of the quantification of respirable crystalline silica by mass on aerosol sampling filters using Raman microscopy

Airborne respirable crystalline silica (RCS) is a hazard that can affect the health of workers and more sensitive measurements are needed for the assessment of worker exposure. To investigate the use of Raman microscopy for the analysis of RCS particulate collected on filters, aliquots of quartz or cristobalite suspended in isopropanol were pipetted onto silver filters. Samples were measured by arbitrarily selecting positions along the filter and collecting spectra at 50 discrete points. The calculated limits of quantification on test samples were between ~0.066 – 0.161 µg and 0.106 – 0.218 µg for quartz and cristobalite respectively. Three respirable quartz calibration dusts (A9950, NIST 1878 and Quin B) with different mass median aerodynamic particle sizes obtained similar Raman response relationships per unit mass. The difference between NIST 1878 and Quin B was not significant (p=0.22). The intermediate measurement precision of replicate samples was 10 - 25% over the measured range for quartz (0.25 – 10 µg) and could potentially be improved. Results from mixtures of quartz and cristobalite were within 10 % of their theoretical values. Results from samples of 5 % quartz in calcite were close to the theoretical quartz mass. The upper measurement limit for a mixture of 20 % RCS in the light absorbing mineral hematite (Fe2O3) was 5 µg. These data show that Raman spectroscopy is a viable option for the quantification of the mass of respirable crystalline silica on filters with a limit of detection approaching 1/10th of that obtained with other techniques. The improvement in sensitivity may enable the measurement of particulate in samples from low concentration environments (e.g. inside a mask) or from miniature samplers operating at low flow rates

Topkapı Sarayı Müzesinde Türk saatleri

Taha Toros Arşivi, Dosya No: 114-Müzelerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Changes in social capital and depressive states of middle-aged adults in Japan

The present study examines the relationships between changes in bonding and bridging types of social capital and depressive states among middle-aged adults in Japan using a nationally representative sample. Data was collected from a nationwide, population-based survey conducted from 2005 to 2013 in nine annual waves. A total of 16,737 middle-aged men and 17,768 middle-aged women provided data. They reported about depressive states, measured by Kessler 6 scores, and bonding and bridging types of social capital, measured by reported participation in different social activities. Latent growth modeling was conducted to examine relations between changes in bonding and bridging types of social capital and depressive states within individuals across the nine waves. The results showed that, for both men and women, increases in bonding social capital were associated with decreases in depressive states, while changes in bridging social capital were not related to changes in depressive states. In addition, the results showed that changes in bonding social capital, but not bonding social capital at the baseline, affected changes in depressive states. Future studies should take changes in social capital as an independent variable into consideration

Current Performance and On-Going Improvements of the 8.2 m Subaru Telescope

An overview of the current status of the 8.2 m Subaru Telescope constructed and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of Japan is presented. The basic design concept and the verified performance of the telescope system are described. Also given are the status of the instrument package offered to the astronomical community, the status of operation, and some of the future plans. The status of the telescope reported in a number of SPIE papers as of the summer of 2002 are incorporated with some updates included as of 2004 February. However, readers are encouraged to check the most updated status of the telescope through the home page, http://subarutelescope.org/index.html, and/or the direct contact with the observatory staff.Comment: 18 pages (17 pages in published version), 29 figures (GIF format), This is the version before the galley proo

Quantum mechanics/molecular mechanics simulation of the ligand vibrations of the water-oxidizing Mn4CaO5 cluster in photosystem II

During photosynthesis, the light-driven oxidation of water performed by photosystem II (PSII) provides electrons necessary to fix CO2, in turn supporting life on Earth by liberating molecular oxygen. Recent high-resolution X-ray images of PSII show that the water-oxidizing center (WOC) is composed of an Mn4CaO5 cluster with six carboxylate, one imidazole, and four water ligands. FTIR difference spectroscopy has shown significant structural changes of the WOC during the S-state cycle of water oxidation, especially within carboxylate groups. However, the roles that these carboxylate groups play in water oxidation as well as how they should be properly assigned in spectra are unresolved. In this study, we performed a normal mode analysis of the WOC using the quantum mechanics/molecular mechanics (QM/MM) method to simulate FTIR difference spectra on the S1 to S2 transition in the carboxylate stretching region. By evaluating WOC models with different oxidation and protonation states, we determined that models of high-oxidation states, Mn(III)2Mn(IV)2, satisfactorily reproduced experimental spectra from intact and Ca-depleted PSII compared with low-oxidation models. It is further suggested that the carboxylate groups bridging Ca and Mn ions within this center tune the reactivity of water ligands bound to Ca by shifting charge via their π conjugation.journal articl

Improved crystal structure solution from powder diffraction data by the use of conformational information

The effect of introducing conformational information to the DASH implementation of crystal structure determination from powder diffraction data is investigated using 51 crystal structures, with the aim of allowing increasingly complex crystal structures to be solved more easily. The findings confirm that conformational information derived from the Cambridge Structural Database is indeed of value, considerably increasing the chances of obtaining a successful structure determination. Its routine use is therefore encouraged