New compounds of natural resources in 2008

Natural products have been the most productive source of new compounds. Hundreds of new compounds are in development. Some of them have pharmaceutical activities, particularly as anticancer and anti-infective agents. Until October, there are 1913 new compounds separated from natural sources in 2008. The compounds have covered a wide range of species, including alkaloids, flavones, terpenoids and so on. It is hoped that more efficient and effective compounds of natural resources wil

Thermoelectric enhancement in PbTe with K, Na co-doping from tuning the interaction of the light and heavy hole valence bands

The effect of K and K-Na substitution for Pb atoms in the rock salt lattice of PbTe was investigated to test a hypothesis for development of resonant states in the valence band that may enhance the thermoelectric power. We combined high temperature Hall-effect, electrical conductivity and thermal conductivity measurements to show that K-Na co-doping do not form resonance states but2 can control the energy difference of the maxima of the two primary valence sub-bands in PbTe. This leads to an enhanced interband interaction with rising temperature and a significant rise in the thermoelectric figure of merit of p-type PbTe. The experimental data can be explained by a combination of a single and two-band model for the valence band of PbTe depending on hole density that varies in the range of 1-15 x 10^19 cm^-3.Comment: 8 figure

The Effect of Urbanization on Temperature Indices in the Philippines

This paper presents a comprehensive analysis of the effect of urbanization on the surface air temperature (SAT) from 1951 to 2018 in the Philippines. The daily minimum temperature (Tmin) and daily maximum temperature (Tmax) records from 34 meteorological stations were used to derive extreme temperature indices. These stations were then classified as urban or rural based on satellite night-lights. The results showed a significant difference in the SAT trends between urban and rural stations, indicative of the effect of urbanization in the country. Larger and more significant warming trends were observed in indices related to Tmin than those related to Tmax. In particular, the effects of urbanization were significant in the annual index series of Tmin, diurnal temperature range, minimum Tmin, percentage of days when Tmin was less than the 10th percentile (TN10p), percentage of days when Tmin was greater than 90th percentile (TN90p), and the number of coldest nights. The effects of urbanization were not as clear on the index series of maximum Tmax (TXx), minimum Tmax (TXn), percentage of days when Tmax was less than 10th percentile (TX10p), and the number of hottest days. The effects of urbanization on the annual series of extreme temperature indices were statistically significant at the 95% confidence level, with the exception of Tmax, TXn, TXx, TX10p, and the number of hottest days. Further analysis revealed that the effect of urbanization was the greatest during the DJF (December–January–February) season. These findings serve as a baseline study that focuses on the countrywide effect of urbanization on SAT trends in the Philippines

Syphilis testing adherence among women with livebirth deliveries: Indianapolis 2014-2016

Background: The number of congenital syphilis (CS) cases in the United States are increasing. Effective prevention of CS requires routine serologic testing and treatment of infected pregnant women. The Centers for Disease Control and Prevention (CDC) recommends testing all pregnant women at their first prenatal visit and subsequent testing at 28 weeks gestation and delivery for women at increased risk. Methods: We conducted a cross-sectional cohort study of syphilis testing among pregnant women with a livebirth delivery from January 2014 to December 2016 in Marion County, Indiana. We extracted and linked maternal and infant data from the vital records in a local health department to electronic health records available in a regional health information exchange. We examined syphilis testing rates and factors associated with non-testing among women with livebirth delivery. We further examined these rates and factors among women who reside in syphilis prevalent areas. Results: Among 21260 pregnancies that resulted in livebirths, syphilis testing in any trimester, including delivery, increased from 71.7% in 2014 to 86.6% in 2016. The number of maternal syphilis tests administered only at delivery decreased from 16.6% in 2014 to 4.04% in 2016. Among women living in areas with high syphilis rates, syphilis screening rates increased from 79.6% in 2014 to 94.2% in 2016. Conclusion: Improvement in prenatal syphilis screening is apparent and encouraging, yet roughly 1-in-10 women do not receive syphilis screening during pregnancy. Adherence to recommendations set out by CDC improved over time. Given increasing congenital syphilis cases, the need for timely diagnoses and prevention of transmission from mother to fetus remains a priority for public health

Structural and functional characterization of Pseudomonas aeruginosa CupB chaperones

Pseudomonas aeruginosa, an important human pathogen, is estimated to be responsible for,10% of nosocomial infections worldwide. The pathogenesis of P. aeruginosa starts from its colonization in the damaged tissue or medical devices (e. g. catheters, prothesis and implanted heart valve etc.) facilitated by several extracellular adhesive factors including fimbrial pili. Several clusters containing fimbrial genes have been previously identified on the P. aeruginosa chromosome and named cup [1]. The assembly of the CupB pili is thought to be coordinated by two chaperones, CupB2 and CupB4. However, due to the lack of structural and biochemical data, their chaperone activities remain speculative. In this study, we report the 2.5 A crystal structure of P. aeruginosa CupB2. Based on the structure, we further tested the binding specificity of CupB2 and CupB4 towards CupB1 (the presumed major pilus subunit) and CupB6 (the putative adhesin) using limited trypsin digestion and strep-tactin pull-down assay. The structural and biochemical data suggest that CupB2 and CupB4 might play different, but not redundant, roles in CupB secretion. CupB2 is likely to be the chaperone of CupB1, and CupB4 could be the chaperone of CupB4:CupB5:CupB6, in which the interaction of CupB4 and CupB6 might be mediated via CupB5

Spin pinning effect to reconstructed oxyhydroxide layer on ferromagnetic oxides for enhanced water oxidation.

Producing hydrogen by water electrolysis suffers from the kinetic barriers in the oxygen evolution reaction (OER) that limits the overall efficiency. With spin-dependent kinetics in OER, to manipulate the spin ordering of ferromagnetic OER catalysts (e.g., by magnetization) can reduce the kinetic barrier. However, most active OER catalysts are not ferromagnetic, which makes the spin manipulation challenging. In this work, we report a strategy with spin pinning effect to make the spins in paramagnetic oxyhydroxides more aligned for higher intrinsic OER activity. The spin pinning effect is established in oxideFM/oxyhydroxide interface which is realized by a controlled surface reconstruction of ferromagnetic oxides. Under spin pinning, simple magnetization further increases the spin alignment and thus the OER activity, which validates the spin effect in rate-limiting OER step. The spin polarization in OER highly relies on oxyl radicals (O∙) created by 1st dehydrogenation to reduce the barrier for subsequent O-O coupling

Validation of ICD-10-CM Codes for Identifying Cases of Chlamydia and Gonorrhea

Background While researchers seek to use administrative health data to examine outcomes for individuals with sexually transmitted infections, the ICD-CM-10 codes used to identify persons with chlamydia and gonorrhea have not been validated. Objectives were to determine the validity of using ICD-10-CM codes to identify individuals with chlamydia and gonorrhea. Methods We utilized data from electronic health records gathered from public and private health systems from October 1, 2015 to December 31, 2016. Patients were included if they were aged 13-44 years and received either 1) laboratory testing for chlamydia or gonorrhea or 2) an ICD-10-CM diagnosis of chlamydia, gonorrhea, or an unspecified STI. To validate ICD-10-CM codes, we calculated positive and negative predictive values, sensitivity, and specificity based on the presence of a laboratory test result. We further examined the timing of clinical diagnosis relative to laboratory testing. Results The positive predictive values for chlamydia, gonorrhea, and unspecified STI ICD-10-CM codes were 87.6%, 85.0%, and 32.0%, respectively. Negative predictive values were high (>92%). Sensitivity for chlamydia diagnostic codes was 10.6% and gonorrhea was 9.7%. Specificity was 99.9% for both chlamydia and gonorrhea. The date of diagnosis occurred on or after the date of the laboratory result for 84.8% of persons with chlamydia, 91.9% for gonorrhea, and 23.5% for unspecified STI. Conclusions Disease specific ICD-10-CM codes accurately identify persons with chlamydia and gonorrhea. However, low sensitivities suggest that most individuals could not be identified in administrative data alone without laboratory test results