Probing the hydrophobic pocket of the active site of aromatase with 4-phenoxy-7 alpha-(phenylthio)-4-androstene-3,17-dione

In order to examine the nature of the hydrophobic pocket at the active site of aromatase, we carried out the synthesis, biochemical evaluation, and molecular modeling studies on 4-phenoxy-7 alpha-(phenylthio)-4-androstenedione 2. Aromatase inhibitory activity of 2 was found to be significantly weaker than that of the 4- and 7 alpha-mono(phenylthio)-substituted derivatives of androstenedione. These results along with those obtained from the modeling studies suggest the existence of a single hydrophobic pocket corresponding to the alpha-face in the C4, C6, C7 region of androstenedione.     

Comparison of antihypertensive effects of nicardipine with nitroglycerin for perioperative hypertension

BACKGROUND: To compare the efficacy of intravenous (iv) nicardipine with nitroglycerin for the treatment for patients with perioperative hypertension. METHODS: Forty patients with perioperative hypertension randomly divided into two groups were treated with intravenous calcium entry blocker, nicardipine, or vasodilator, nitroglycerin. Haemodynamic measurements including mean arterial and pulmonary arterial pressure, central venous and pulmonary capillary wedge pressure, and cardiac output were recorded; peripheral and pulmonary vascular resistance were calculated. RESULTS: Both medications were effective in reducing blood pressure and controlling haemodynamics. During the maintenance by continuous iv infusion, nicardipine controlled hypertension more rapidly than nitroglycerin (nicardipine 10.5 +/- 2.5 min and nitroglycerin 18.7 +/- 2.8 min, p < 0.05) without significant alteration in heart rate. The total frequency of dose adjustments required to achieve therapeutic response was significantly less in the nicardipine-treated group (2.5 +/- 0.3 for nicardipine and 6.2 +/- 1.4 for nitroglycerin, p < 0.05). Incidence of hypotensive episodes during the infusion were observed in both groups [nicardipine 5% (1/20) and nitroglycerin 30% (6/20), p < 0.05]. CONCLUSIONS: Intravenous nicardipine is as effective as nitroglycerin in the treatment of perioperative hypertension. Specific advantages have been identified such as stable dose-response effect, less hypotensive and tachycardial effects during the use of iv nicardipine in treatment of hypertensive patients.     

Localization of dopamine1A receptor mRNA in different vascular beds in rat: a nonradioactive in situ hybridization study

In situ hybridization of a biotin-labeled specific dopamine1A (D1A) receptor gene oligonucleotide probe combined with computer-assisted image analyzer was used to directly visualize D1A receptor mRNA and quantify the relative mRNA levels in sections of rat aorta and pulmonary and caudal arteries. Positive D1A receptor mRNA signals were found in rat aorta and pulmonary arteries, while no specific signals could be detected in the caudal artery. D1A receptor mRNA was located mainly within the medial layer of aorta, with intimal distribution in the pulmonary artery. The density of D1A receptor mRNA in different vascular beds demonstrated heterogeneity. D1A receptor mRNA levels in the aorta were much higher than those in the pulmonary artery (p < 0.01). These results demonstrate the existence of D1A receptor mRNA in both aorta and pulmonary beds, although with different distribution and density. The results further support the heterogeneity of the D1A receptor in different vascular beds.     

Oxygen barrier properties of biaxially oriented polypropylene/polyvinyl alcohol blend films

The biaxially oriented PP/PVA blend film was prepared and had the higher oxygen barrier property by about 130 times than that of a biaxially oriented PP film. When the viscosity ratio (η_d(PVA)/η_m(PP)) decreased, the dispersed PVA phase was developed into platelets during stretching process. Oxygen permeability was dependent on the number and size of PVA platelet. However, the Oxygen permeability was not sensitively changed in above 25 wt% of PVA. To obtain excellent barrier property, the optimum amount of plasticizer and initiator was required. A pasticizer was related to the size and degree of crystallization of PVA platelet. An initiator played the role of a compatibilizer. The oxygen barrier was enhanced with increasing the viscosity of PP and draw ratio. The higher viscosity of PP was advantageous for preventing the delamination of a blend film, and the moisture vapor permeability was not affected with the laminar structure. As a result, the biaxially oriented PP/PVA blend film had the potential of substituting for the PVDC coated BOPP film.     

Incompressible laminar flow near a corner of 90° angle

Numerical integration is conducted for two-dimensional incompressible laminar flow over a 90° corner. Using Newton’s method, the Navier-Stokes equations are generated up toRe=2800, with the result that the corner generates a second bubble nearRe=800. There exist distinct patterns for the evolution of the pressure gradient and the position of a separation point. AsRe is increased the pressure gradient tends to approach zero over the recirculated region and shows sharper variations near the separation and reattachment points. Thus, these results confirm the free streamline model for separation proposed by Sychev.     

Observational method for field performance of prefabricated vertical drains

An exponential formula is used to best-fit theoretical and measured time–settlement (or excess pore pressure) data over the full range of consolidation. The formula fits well theoretical consolidation solutions and measured data regardless of using the incompletely consolidated data, and it is possible to reliably predict the ultimate values. This result has a different trend from those of the hyperbolic and Asaoka (1978) methods. Thus the coefficients of horizontal consolidation and the mobilised discharge capacity q_w(mob) can be expressed in terms of parameters of the exponential formula corresponding to the measured data and the theoretical solutions. The application of the proposed method to six case records on three construction sites (with a maximum drainage path l_m of 7−50 m) indicates that the coefficient of horizontal consolidation for the ideal condition are likely to be used to reconstruct the monitored time–settlement curve and also to adjust the hydraulic and consolidation properties of each monitored point. Based on back-analysis, the mobilised and required discharge capacity for a preliminary design guideline are recommended as: q_w(mob) = (1–5)k_hl_m² and q_w(req) = 19.63k_hl_m², where k_h is the horizontal permeability of soil.     

Nanostructure and mechanical properties of aromatic polyamide and reactive organoclay nanocomposites

Aromatic polyamide/organoclay nanocomposites were synthesized using the solution blending technique. Treatment of montmorillonite clay with p-phenylenediamine produced reactive organophilic clay for good compatibility with the matrix. Polyamide chains were prepared by condensing a mixture of 1,4-phenylenediamine and 4-4′-oxydianiline with isophthaloyl chloride under anhydrous conditions. These chains were end capped with carbonyl chloride using 1% extra acid chloride near the end of reaction to develop the interactions with organoclay. The dispersion and structure–property relationship were monitored using FTIR, XRD, FE-SEM, TEM, DSC and tensile testing of the thin films. The structural investigations confirmed the formation of delaminated and disordered intercalated morphology with nanoclay loadings. This morphology of the nanocomposites resulted in their enhanced mechanical properties. The tensile behavior and glass transition temperature significantly augmented with increasing organoclay content showing a greater interaction between the two disparate phases.     

Differences in traffic violations and at-fault crashes between license suspension and revocation

Upon conviction for particular traffic offenses, drivers can have their licenses revoked. Drivers who receive license revocation have an opportunity to apply for a sentence reduction, and some of those who apply receive a reduced sanction — license suspension. There may be differences between drivers whose license was revoked as originally sentenced and drivers who received the reduced sanction of license suspension with regard to traffic violations and crashes after driving privileges are restored. This study verified the differences during the follow-up periods of 6, 12, and 18 months using analysis of covariance and the t-test with stratified samples based on the police profiles of approximately 154,000 drivers in South Korea. The study found that drivers in the group whose license had been suspended committed traffic violations and caused traffic crashes less often for all time periods than those whose license had been revoked. However, omitted factors such as the attitude of suspended drivers and exposure to traffic violations and crashes (e.g., driving frequency after license reinstatement), are likely to affect the findings; thus, caution should be exercised when the findings are referenced for policy implications.