• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.287-293
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• 2009

The dried roots of Danshen (Salvia miltiorrhiza) and Sanchi (Panax notoginseng) have been widely used in traditional Chinese medicine for promoting blood circulation as well as various other bodily functions. Here we investigated the effects of a mixture of aqueous extracts of Danshen and Sanchi, named PASEL, on blood pressure and vascular contractility in rats. Orally administered PASEL (62.5 mg/kg and 250 mg/kg, for 5 weeks) lowered the blood pressure of spontaneous hypertensive rats (SHR) but this was not observed in normal Wistar-Kyoto rats (WKR). We then investigated the effects of PASEL on the arterial contraction of the small branches of cerebral arteries (CAs) and large conduit femoral arteries (FAs) in rats. PASEL did not affect high-K (KCI 60 mM)- or phenyleprine (PhE)-induced contracture of FAs. The myogenic response, a reactive arterial constriction in response to increased luminal pressure, of small CA was dose-dependently suppressed by PASEL in SHR as well as control rats. Interestingly, the KCI-induced contraction of small CAs was slowly reversed by PASEL, and this effect was more prominent in SHR than control WKR. PASEL did not inhibit angiotensin-converting enzyme (ACE) activity. These results demonstrated that the antihypertensive effect of PASEL might be primarily mediated by altering the arterial MR, not by direct inhibition of L-type $Ca^{2+}$ channels or by ACE inhibition.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.301-307
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• 2009

Inflammatory processes of vascular endothelial cells play a key role in the development ofatherosclerosis. We determined the anti-inflammatory effects and mechanisms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on LPS-treated human umbilical vein endothelial cells (HUVECs) to evaluate their cardioproteerive potential. Cells were pretreated with DHA, EPA, or troglitazone prior to activation with LPS. Expression of COX-2, prostaglandin $E_2$ ($PGE_2$) and IL-6 production, and $NF-{\kappa}B$ activity were measured by Western blot, ELISA, and luciferase activity, respectively. Results showed that EPA, DHA, or troglitazone significantly reduced COX-2 expression, $NF-{\kappa}B$ luciferase activity, and $PGE_2$ and IL-6 production in a dose-dependent fashion. Interestingly, low doses (10 ${\mu}$M) of DHA and EPA, but not troglitozone, significantly increased the activity of $NF-{\kappa}B$ in resting HUVECs. Our study suggests that while DHA, EPA, and troglitazone may be protective on HUVECs under inflammatory conditions in a dose-dependent manner. However there may be some negative effects when the concentrations are abnormally low, even in normal endothelium.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.884-888
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• 2009

Effect of citrus pectin oligosaccharides produced by irradiation was studied on the ability to improve lipid metabolism and hypercholesterolemia in mice fed high cholesterol diets. A total of 35 mice were divided into 5 groups and fed the following diets for 6 weeks: normal diet (C), 0.5% cholesterol (CH), 0.5% cholesterol+5% non-irradiated pectin (P), 0.5% cholesterol+5% irradiated pectin at 20 kGy (PIR), and 0.5% cholesterol+5% irradiated at 20 kGy and dialyzed (PIR-F). CH group had significantly higher serum triglycerides, total cholesterol, and low density lipoprotein (LDL)-cholesterol contents than pectin oligosaccharide-treated groups (p<0.05). Triglycerides and total cholesterol contents was the lowest in C and PIR-F and followed by PIR and P group, and CH group had significantly higher LDL-cholesterol. Serum high density lipoprotein (HDL)-cholesterol content in C group was not different from that in CH and P groups, but lower than that of PIR and PIR-F groups. These results suggest that pectin oligosaccharides produced by irradiation can reduce the levels of serum triglyceride, total cholesterol, and LDL-cholesterol in the blood of mice fed high-cholesterol diets and therefore, irradiation can be used as a tool to produce functional oligosaccharides from citrus pectin.

• Ocean and Polar Research
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• v.32 no.2
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• pp.157-164
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• 2010

A marine alga, Spirulina maxima, was extracted under high pressure and low temperature conditions at 500 MPa and $60^{\circ}C$ for 5 and 10 min. A high pressure of 500 MPa was applied to improve process yields because of low temperature extraction. This method resulted in highest higher extraction yield of 26.1% (w/w) in comparison to those results obtained from conventional extraction methods which produced a yield of 17.6% (w/w) from water. The extracts from this process also showed 19% of low cytotoxicity against human normal fibroblast cells in adding 1.0 mg/ml of the highest concentration. The crude extract significantly reduced the production of Prostaglandin $E_2$ ($PGE_2$) from CCD-986sk cells and increased nitric oxide production by macrophages. These higher activities of enhancing skin immune functions were found to have high antioxidant extract properties, like a 98% increase in DPPH radical scavenging activity. The extracts from the high pressure process showed a higher elution of active components than other processes and generated new compounds based on HPLC analysis. This clearly indicates that the extracts from high pressure and low temperature conditions have higher skin immune activation properties that have not been previously reported.

• Clinical and Experimental Pediatrics
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• v.58 no.12
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• pp.478-483
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• 2015

Purpose: Information on the clinical features of lung abscess, which is uncommon in children, at hospitalization is helpful to anticipate the disease course and management. There is no report concerning lung abscess in Korean children. We aimed to identify the clinical characteristics of pediatric lung abscess and compare the difference between primary and secondary abscess groups. Methods: The medical records of 11 lung abscess patients (7 males and 4 females) from March 1998 to August 2011 at two university hospitals were retrospectively reviewed. The clinical characteristics, symptoms, underlying disease, laboratory and radiologic findings, microbiological results, and treatments were examined. Results: Six patients had underlying structural-related problems (e.g., skeletal anomalies). No immunologic or hematologic problem was recorded. The mean ages of the primary and secondary groups were 2.4 and 5.3 years, respectively, but the difference was not statistically significant. The mean length of hospital stay was similar in both groups (22.8 days vs. 21.4 days). Immunologic studies were performed in 3 patients; the results were within the normal range. Most patients had prominent leukocytosis. Seven and 4 patients had right and left lung abscess, respectively. Staphylococcus aureus, Streptococcus pneumoniae, and antimycoplasma antibodies were detected in both groups. Two patients with primary lung abscess were administered antibiotics in the absence of other procedures, while 8 underwent interventional procedures, including 5 with secondary abscess. Conclusion: The most common symptoms were fever and cough. All patients in the primary group were younger than 3 years. Structural problems were dominant. Most patients required interventional procedures and antibiotics.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.986-993
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• 2001

Translation Initiation in prokaryotes involves the formation of a 30 S preinitiation complex, in which translation initiation factors play a role in the stimulation of fMet-tRNA (fMet) binding. However, the specific function and precise mechanism of initiation factor IF1 are still unclear. One a functionally active factor with a high purity. In the present study a large quantity of active IF was rapidly purified, obtained by the overexpression of the infA gene, and then used for a functional study. The induction of infA did not appreciably affect the growth rate of the protease-deficient strain E. coli AR68 harboring the IF1 overproducing plasmid. The level of IF1 obtained was approximately $1-2\%$ of the total cell protein, which enabled the yield of highly purified IF1 (>$98\%$ pure) to be increased to 0.15 mg of IF1/g of cells. The IF1 was isolated within one day by the centrifugatioin of the ribosomal washed fraction, by ammonium sulfate fractionation, chromatography on batch of phosphocellulose, and FPLC Mono S. The overexpressed IF1 was found to be comparable to the factor isolated from normal cells, as determined by migration in NEPHGE/SDS 2-D gels. For binding of fMet-tRNA(fMet) to the 30 S ribosomal subunitis, relatively high levels of binding were obtained when IF2 was present. The addition of IF1 up to 110 pmol proportionally stimulated the binding to a variable extent. This IF1-dependent stimulation of the 30 S preinitiation complex formation demonstrated that IF1 would appear to be exclusively essential for promoting the initiation phase of protein synthesis.

• Structural Engineering and Mechanics
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• v.53 no.5
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• pp.939-956
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• 2015

In this study, in order to propose an efficient model to predict the torque capacity of steel fiber reinforced concrete (SFRC) beams, the existing experimental data related to torsional response of beams is reviewed. It is observed that existing data neglects the effects of some parameters on the variation of torque capacity. Thus, an experimental research was also conducted to obtain the effects of neglected parameters. In the experimental study, a total of seventeen SFRC beams are tested against torsion. The parameters considered in the experiments are concrete compressive strength, steel fiber aspect ratio, volumetric ratio of steel fibers and longitudinal reinforcement ratio. The effect of each parameter is discussed in terms of torque versus unit angle of twist graphs. The data obtained from this experimental research is also combined with the data got from previous studies and employed in artificial neural network (ANN) analysis to estimate the ultimate torque capacity of SFRC beams. In addition to parameters considered in the experiments, aspect ratio of beam cross-section, yield strengths of both transverse and longitudinal reinforcements, and transverse reinforcement ratio are also defined as parameters in ANN analysis due to their significant effects observed in previous studies. Assessment of the accuracy of ANN analysis in estimating the ultimate torque capacity of SFRC beams is performed by comparing the analytical and experimental results. Comparisons are conducted in terms of root mean square error (RMSE), mean absolute error (MAE) and coefficient of efficiency ($E_f$). The results of this study revealed that addition of steel fibers increases the ultimate torque capacity of reinforced concrete beams. It is also found that ANN is a powerful method and a feasible tool to estimate ultimate torque capacity of both normal and high strength concrete beams within the range of input parameters considered.

• Geomechanics and Engineering
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• v.11 no.3
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• pp.345-359
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• 2016

In order to investigate the influence of the interfacial angel on failure characteristics and mechanism of combined coal-rock mass, 35 uniaxial/biaxial compressive simulation tests with 5 different interfacial angels of combined coal-rock samples were conducted by PFC2D software. The following conclusions are drawn: (1) The compressive strength and cohesion decrease with the increase of interfacial angle, which is defined as the angle between structure plane and the exterior normal of maximum principal plane, while the changes of elastic modulus and internal friction angle are not obvious; (2) The impact energy index $K_E$ decreases with the increase of interfacial angle, and the slip failure of the interface can be predicted based on whether the number of acoustic emission (AE) hits has multiple peaks or not; (3) There are four typical failure patterns for combined coal-rock samples including I (V-shaped shear failure of coal), II (single-fracture shear failure of coal), III (shear failure of rock and coal), and IV (slip rupture of interface); and (4) A positive correlation between interfacial angle and interface effect is shown obviously, and the interfacial angle can be divided into weak-influencing scope ($0-15^{\circ}$), moderate-influencing scope ($15-45^{\circ}$), and strong-influencing scope (> $45^{\circ}$), respectively. However, the confining pressure has a certain constraint effect on the interface effect.

• Structural Engineering and Mechanics
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• v.74 no.6
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• pp.723-735
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• 2020

This study is reported the adhesion failure in adhesive bonded composite and specifically for the T-joint structure. Three-dimensional finite element analysis has been performed using a commercial tool and the necessary outcomes are obtained via an eight noded solid element (Solid 185-element) from the library of ANSYS. The structural analysis input has been incurred through ANSYS parametric design language (APDL) code. The normal and shear stress distributions along different layers of the joint structure have been evaluated as the final outcomes. Based on the stress distributions, failure location in the composite joint structure has been identified by using the Tsai-Wu stress failure criterion. It has been found that the failure index is maximum at the interface between flange and web part of the joint (top layer) which indicates the probable location of failure initiation. This kind of failures are considered as adhesion failure and the failure propagation is governed by strain energy release rate (SERR) of fracture mechanics. The different adhesion failure lengths are also considered at the failure location to calculate the SERR values i.e. mode I fracture (opening), mode II fracture (sliding) and mode III fracture (tearing) along the failure front. Also, virtual crack closure technique (VCCT) principle of fracture mechanics steps is used to calculate the above said SERRs. It is found that the mode I SERR is more dominating compared to other two modes of failure for the joint considered. Finally, the influences of various parametric (geometrical and material) effect on SERR of the joint structure are evaluated and discussed in details.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.242-248
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• 2013

Endotoxins are part of the outer membrane of the cell wall of gram-negative bacteria and are continuously released during bacterial growth. Endotoxins typically induce severe sepsis and septic shock, which cause more than 50% of mortalities. Endotoxins are easily measured in the serum by the limulus amebocyte lysate (LAL) test. However, a nonspecific result is obtained, because the high concentration of serum proteins disturbs the enzyme reaction of the LAL test. In order to solve this problem, the LAL test was performed in this study after the centrifugation of the boiled serum samples to remove the impurities. As a result, among the various conditions examined, endotoxin measurement with the LAL test was the most accurate and repeatable after centrifugation of the boiled serum at $100^{\circ}C$. Moreover, the endotoxin was accurately and repeatedly measured from the prepared sera of mice that had been administered an intraperitoneal injection of purified lipopolysaccharides (LPS) or E. coli. Therefore, the application of centrifugation to remove impurities from boiled serum gives an accurate measurement of endotoxins in the sera of normal subjects or patients, and this will lead to the improved diagnosis and prevention of diseases caused by endotoxins. In addition, the centrifugation of boiled serum samples should be considered and included in the development of endotoxin test kits.