A Study on the Flexural Behavior of Profiled Composite Beams

An analytical study on the behavior of composite beams, which are composed of cold-formed steel sheeting and normal strength concrete, is described. An analytical method to trace the nonlinear behavior of a composite beam is developed to include the nonlinear material properties of steel sheeting, reinforcing steel bar and concrete. However, since the method is complex and tedious to use, two simple formulas for the nonlinear moment-curvature relation of the composite beam have been proposed. A simple power model, which has been originally used to predict the flexural capacity of the beam to column connections, is proposed as the first formula. The second formula is composed of two experimental set of functions to express separately, the moment-curvature relation in the elastic and the plastic range. Both formulas have been proven to be accurate and useful for the design of profiled composite beams. The load-deflection behavior of the beams has been simulated by the step-by-step numerical integration method and is compared to available test results. The effects of the concrete cube strength and the thickness and strength of the cold-formed steel section on the flexural strength of the composite beam have also been studied

Electrical conductivity enhancement of epitaxially grown TiN thin films

Titanium nitride (TiN) presents superior electrical conductivity with mechanical and chemical stability and compatibility with the semiconductor fabrication process. Here, we fabricated epitaxial and polycrystalline TiN (111) thin films on MgO (111), sapphire (001), and mica substrates at 640oC and room temperature by using a DC sputtering, respectively. The epitaxial films show less amount of surface oxidation than the polycrystalline ones grown at room temperature. The epitaxial films show drastically reduced resistivity (~30 micro-ohm-cm), much smaller than the polycrystalline films. Temperature-dependent resistivity measurements show a nearly monotonic temperature slope down to low temperature. These results demonstrate that high temperature growth of TiN thin films leads to significant enhancement of electrical conductivity, promising for durable and scalable electrode applications.Comment: 14 pages, 3 figure

Beneficial Effect of Efonidipine, an L- and T-Type Dual Calcium Channel Blocker, on Heart Rate and Blood Pressure in Patients With Mild-to-Moderate Essential Hypertension

Background and Objectives: Efonidipine hydrochloride, an L- and T-type dual calcium channel blocker, is suggested to have a heart rate (HR)-slowing action in addition to a blood pressure (BP)-lowering effect. The aim of this study was to determine the effect of efonidipine on HR and BP in patients with mild-to-moderate hypertension. Subjects and Methods: In a multi-center, prospective, open-labeled, single-armed study, we enrolled 53 patients who had mild-to-moderate hypertension {sitting diastolic BP (SiDBP) 90-110 mmHg}. After a 2-week washout, eligible patients were treated with efonidipine (40 mg once daily for 12 weeks). The primary end point was the change in HR from baseline to week 12. The secondary end-point included the change in trough sitting BP and 24-hour mean BP between baseline and week 12. Laboratory and clinical adverse events were monitored at each study visit (4, 8, and 12 weeks). Results: Fifty-two patients were included in the intention-to-treat analysis. After 12 weeks of treatment with efonidipine, the resting HR decreased significantly from baseline to week 12 (from 81.5??5.3 to 71.8??9.9 beats/minute (difference, -9.9??9.0 beats/minute), p<0.0001}. The trough BP {sitting systolic blood pressure (SiSBP) and SiDBP} and 24-hour mean BP also decreased significantly (SiSBP: from 144.6??8.2 to 132.9??13.5 mmHg, p<0.0001; SiDBP: from 96.9??5.4 to 88.3??8.6 mmHg, p<0.0001, 24-hour mean systolic BP: from 140.4??13.5 to 133.8??11.6 mmHg, p<0.0001; 24-hour mean diastolic BP: from 91.7??8.7 to 87.5??9.5 mmHg, p<0.0001). Conclusion: Efonidipine was effective in controlling both HR and BP in patients with mild-to-moderate hypertension. Copyright ?? 2010 The Korean Society of Cardiology

Human AP Endonuclease 1: A Potential Marker for the Prediction of Environmental Carcinogenesis Risk

Human apurinic/apyrimidinic endonuclease 1 (APE1) functions mainly in DNA repair as an enzyme removing AP sites and in redox signaling as a coactivator of various transcription factors. Based on these multifunctions of APE1 within cells, numerous studies have reported that the alteration of APE1 could be a crucial factor in development of human diseases such as cancer and neurodegeneration. In fact, the study on the combination of an individual’s genetic make-up with environmental factors (gene-environment interaction) is of great importance to understand the development of diseases, especially lethal diseases including cancer. Recent reports have suggested that the human carcinogenic risk following exposure to environmental toxicants is affected by APE1 alterations in terms of gene-environment interactions. In this review, we initially outline the critical APE1 functions in the various intracellular mechanisms including DNA repair and redox regulation and its roles in human diseases. Several findings demonstrate that the change in expression and activity as well as genetic variability of APE1 caused by environmental chemical (e.g., heavy metals and cigarette smoke) and physical carcinogens (ultraviolet and ionizing radiation) is likely associated with various cancers. These enable us to ultimately suggest APE1 as a vital marker for the prediction of environmental carcinogenesis risk

Effect of Low Frequency Cerebellar Repetitive Transcranial Magnetic Stimulation on Balance Impairment in Patients With Cerebral Infarction

Objective To investigate the effect of low frequency cerebellar repetitive transcranial magnetic stimulation (rTMS) on balance impairment in patients with cerebral infarction. Methods Thirty-two patients were randomly divided into two groups: rTMS group (n=16) and control (n=16). In the rTMS group, treatment was performed five times per week for 2 weeks (10 sessions), and in the control group, a sham coil was used with the sound and sensation of scalp similar to the rTMS coil. Patients in both groups underwent a conventional rehabilitation program. Berg Balance Scale (BBS) was used as the primary outcome measurement. Timed Up and Go test (TUG), 10-m walk test (10mWT), and Activity-specific Balance Confidence scale (ABC) were used as the secondary outcome measurement. All scales were measured at baseline (T0), after 10 sessions of rTMS (T1), and at 4 weeks after treatment completion (T2) by therapists with over 5 years of clinical experience. Results There were significant improvements between T0 and T1, and between T0 and T2, for all assessed items in the rTMS group. Whereas there were significant improvements between T0 and T1, and between T0 and T2, for the BBS and 10mWT in the control group. TUG (-4.87±5.05 vs. -0.50±2.97 seconds) and ABC score (8.10±8.33 vs. 0.16±0.97) were observed significant differences in comparison of the changes from T0 to T1 between the two group. BBS score (4.40±3.66 vs. 1.88±3.14), TUG (-4.87±4.56 vs. -0.62±2.96 seconds) and ABC score (8.22±7.70 vs. -0.09±0.86) differed significantly from T0 to T2 between the two groups. Conclusion Our findings suggest that low-frequency cerebellar rTMS is helpful for improving balance in patients with cerebral infarction, and maybe a beneficial treatment for these patients

Significance of p27kip1 as potential biomarker for intracellular oxidative status

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of p27kip1 (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 µM) downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 µM hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-1β), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-1β)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-1β. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status

Hepatoprotective Activity of Licorice Water Extract against Cadmium-induced Toxicity in Rats

Licorice is commonly used as a cure for digestive disorders and as a detoxification agent in East Asia. This study investigated the protective effect of licorice water extract against cadmium (CdCl2, Cd)-induced liver toxicity in rats. To induce acute toxicity, Cd (4 mg/kg body weight) was dissolved in normal saline and intravenously (i.v.) injected into rats. The rats then received either a vehicle or licorice water extract (50, 100 mg/kg/day) for 3 days, and were subsequently exposed to a single injection of Cd 24 h after the last licorice/vehicle treatment. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were significantly increased by Cd treatment. In contrast, pretreatment with licorice reduced ALT, AST and LDH. In histopathological analysis, licorice decreased the central necrosis around central veins, the peripheral hemorrhage around portal triads, the percentage of degenerative hepatic regions (%/mm2 hepatic parenchyma) and the number of degenerative hepatic cells (N/100 hepatic cells). Licorice also inhibited the increment of Bad (a BH3 domain-containing protein) translocation by Cd in liver cells. These results demonstrate that licorice could have a hepatoprotective effect by inhibiting the translocation of Bad to the mitochondria in Cd-intoxificated rats