606 research outputs found
THEORETICAL STUDY OF SOLVATION OF IONS BY ARGON ATOMS
Gas phase experiments have been used to study the molecular properties of finite systems in order to minimize the environmental perturbations. The measurements conducted in vacuum environment setup the standard reference value of experimental observables which builds up the foundation of non-vacuum scientific researches. The solvents, e.g. noble gas atoms, used in the gas phase experiments play an important role, i.e. cooling down the system temperature in order to approach the 0?K and provide better spectroscopic measurement quality. The binding position of the solvent atoms also impacts the interpretation of the experimental results. The aid from the theoretical studies was limited due to the computational expense. Three projects are shown in this thesis to show the theoretical challenges in studying different complex systems. The first project is a model potential development with the inclusion of electron correlation at quantum chemistry level to study the (H2O)Arn- clusters. The second project is using the ab inito calculations to explain the infrared spectroscopic measurement of Mg+(H2O)Arn clusters. The last project is a study of the complex electronic structure of Fe+(H2O)Arn clustes with using state-of-the-art ab intio method
Bridge scour evaluation based on ambient vibration
The vulnerability of bridges to hazards such as earthquakes, wind and floods necessitates special structural characteristics. To guarantee the stability of bridge structures, the precise evaluation of the scour depth of bridge foundation has recently become an important issue, as most of the unexpected damage to or collapse of bridges has been attributed to hydraulic issues. In this paper, a vibration-based bridge health monitoring system that utilizes only the response of superstructure to rapidly evaluate the embedded depth of a bridge column is proposed. To clarify the complex fluid-solid coupling phenomenon, the effects of embedded depth and water level were first verified through a series of static experiments. A confined finite element model simulated by soil spring effects was then established to illustrate the relationship between the fundamental frequency and the embedded depth. Using the proposed algorithm, the health of the bridge is able to be inferred by processing the ambient vibration response of the superstructure. To implement the proposed algorithm, a SHM prototype system monitoring environmental factors such as temperature, water level, and inclination was developed to support on-line processing. The performance of the proposed system was verified by a series of dynamic bridge scour experiments conducted in a laboratory flume and compared with readings from a water-proof camera. The results showed that using the proposed vibration-based bridge health monitoring system, the embedded depth of bridge column during complex scour processes is able to be reliably calculated
Caffeic acid phenethyl amide ameliorates ischemia/reperfusion injury and cardiac dysfunction in streptozotocin-induced diabetic rats
BACKGROUND: Caffeic acid phenethyl ester (CAPE) has been shown to protect the heart against ischemia/reperfusion (I/R) injury by various mechanisms including its antioxidant effect. In this study, we evaluated the protective effects of a CAPE analog with more structural stability in plasma, caffeic acid phenethyl amide (CAPA), on I/R injury in streptozotocin (STZ)-induced type 1 diabetic rats. METHODS: Type 1 diabetes mellitus was induced in SpragueāDawley rats by a single intravenous injection of 60Ā mg/kg STZ. To produce the I/R injury, the left anterior descending coronary artery was occluded for 45Ā minutes, followed by 2Ā hours of reperfusion. CAPA was pretreated intraperitoneally 30Ā minutes before reperfusion. An analog devoid of the antioxidant property of CAPA, dimethoxyl CAPA (dmCAPA), and a nitric oxide synthase (NOS) inhibitor (NĻ-nitro-l-arginine methyl ester [l-NAME]) were used to evaluate the mechanism involved in the reduction of the infarct size following CAPA-treatment. Finally, the cardioprotective effect of chronic treatment of CAPA was analyzed in diabetic rats. RESULTS: Compared to the control group, CAPA administration (3 and 15Ā mg/kg) significantly reduced the myocardial infarct size after I/R, while dmCAPA (15Ā mg/kg) had no cardioprotective effect. Interestingly, pretreatment with a NOS inhibitor, (l-NAME, 3Ā mg/kg) eliminated the effect of CAPA on myocardial infarction. Additionally, a 4-week CAPA treatment (1Ā mg/kg, orally, once daily) started 4Ā weeks after STZ-induction could effectively decrease the infarct size and ameliorate the cardiac dysfunction by pressure-volume loop analysis in STZ-induced diabetic animals. CONCLUSIONS: CAPA, which is structurally similar to CAPE, exerts cardioprotective activity in I/R injury through its antioxidant property and by preserving nitric oxide levels. On the other hand, chronic CAPA treatment could also ameliorate cardiac dysfunction in diabetic animals
Assessment of density functional approximations for the hemibonded structure of water dimer radical cation
Due to the severe self-interaction errors associated with some density
functional approximations, conventional density functionals often fail to
dissociate the hemibonded structure of water dimer radical cation (H2O)2+ into
the correct fragments: H2O and H2O+. Consequently, the binding energy of the
hemibonded structure (H2O)2+ is not well-defined. For a comprehensive
comparison of different functionals for this system, we propose three criteria:
(i) The binding energies, (ii) the relative energies between the conformers of
the water dimer radical cation, and (iii) the dissociation curves predicted by
different functionals. The long-range corrected (LC) double-hybrid functional,
omegaB97X-2(LP) [J.-D. Chai and M. Head-Gordon, J. Chem. Phys., 2009, 131,
174105.], is shown to perform reasonably well based on these three criteria.
Reasons that LC hybrid functionals generally work better than conventional
density functionals for hemibonded systems are also explained in this work.Comment: 10 pages, 5 figures, 4 table
Effect of Different Parts (Leaf, Stem and Stalk) and Seasons (Summer and Winter) on the Chemical Compositions and Antioxidant Activity of Moringa oleifera
Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part
Safety and effectiveness of new embolization microspheres SCBRM for intermediate-stage hepatocellular carcinoma: A feasibility study
Transarterial chemoembolization (TACE) is, currently, the recommended treatment for hepatocellular carcinoma (HCC). However, long-term chemoembolization triggers the inflammatory response and may lead to postembolization syndrome (PES). Although several types of degradable microspheres have been developed to reduce drug toxicity and PES incidence, the clinical outcomes remain unsatisfactory. Previously, we have developed a new type of spherical, calibrated, biodegradable, radiopaque microspheres (SCBRM) and demonstrated their safety and efficacy in a pig model. Thus, the goal of this feasibility study was to determine the clinical safety and efficacy of the new SCBRM in intermediate-stage HCC patients. In this study, 12 intermediate-stage HCC patients underwent TACE using SCBRM with a calibrated size of 100ā250 Ī¼m. The disease control rates at 1 month and 3 months after TACE-SCBRM treatment were 100% and 75.0%, respectively. The objective response rates at 1 month and 3 months after treatment were 66.7% and 58.3%, respectively. Very few adverse events were observed with one patient developing nausea. One day after the treatment, alanine aminotransferase, alanine aminotransferase, and total bilirubin levels were slightly elevated in the patients, but all returned to baseline on day 7. The median and mean overall survival times were 33 months (interquartile range, 12.8ā42.0) and 29.2 Ā± 14.3 months, respectively. The 1-year and 2-year survival rates were 91.7% and 58.3%, respectively. In conclusion, TACE with the new SCBRM microspheres is clinically safe and effective, and it represents a promising approach in the management of intermediate-stage HCC
Down-regulation of PKCĪ¶ in renal cell carcinoma and its clinicopathological implications
<p>Abstract</p> <p>Background</p> <p>Metastatic renal cell carcinoma (RCC) is highly resistant to systemic chemotherapy. Unfortunately, nearly all patients die of the metastatic and chemoresistant RCC. Recent studies have shown the atypical PKCĪ¶ is an important regulator of tumorigenesis. However, the correlation between PKC<b>Ī¶ </b>expression and the clinical outcome in RCC patients is unclear. We examined the level of PKCĪ¶ expression in human RCC.</p> <p>Methods</p> <p>PKCĪ¶ mRNA and protein expressions were examined by real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) respectively in RCC tissues of 144 patients. Cellular cytotoxicity and proliferation were assessed by MTT.</p> <p>Results</p> <p>PKCĪ¶ expression was significantly higher in normal than in cancerous tissues (<it>P </it>< 0.0001) by real-time PCR and IHC. Similarly, PKCĪ¶ expression was down-regulated in four renal cancer cell lines compared to immortalized benign renal tubular cells. Interestingly, an increase of PKCĪ¶ expression was associated with the elevated tumor grade (<it>P </it>= 0.04), but no such association was found in TNM stage (<it>P </it>= 0.13). Tumors with higher PKCĪ¶ expression were associated with tumor size (<it>P </it>= 0.048). Expression of higher PKCĪ¶ found a poor survival in patients with high tumor grade. Down-regulation of PKCĪ¶ showed the significant chemoresistance in RCC cell lines. Inactivation of PKCĪ¶ expression enhanced cellular resistance to cisplatin and paclitaxel, and proliferation in HK-2 cells by specific PKC<b>Ī¶ </b>siRNA and inhibitor.</p> <p>Conclusions</p> <p>PKCĪ¶ expression was associated with tumorigenesis and chemoresistance in RCC.</p
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Multi-scale symbolic entropy analysis provides prognostic prediction in patients receiving extracorporeal life support
Introduction: Extracorporeal life support (ECLS) can temporarily support cardiopulmonary function, and is occasionally used in resuscitation. Multi-scale entropy (MSE) derived from heart rate variability (HRV) is a powerful tool in outcome prediction of patients with cardiovascular diseases. Multi-scale symbolic entropy analysis (MSsE), a new method derived from MSE, mitigates the effect of arrhythmia on analysis. The objective is to evaluate the prognostic value of MSsE in patients receiving ECLS. The primary outcome is death or urgent transplantation during the index admission. Methods: Fifty-seven patients receiving ECLS less than 24 hours and 23 control subjects were enrolled. Digital 24-hour Holter electrocardiograms were recorded and three MSsE parameters (slope 5, Area 6ā20, Area 6ā40) associated with the multiscale correlation and complexity of heart beat fluctuation were calculated. Results: Patients receiving ECLS had significantly lower value of slope 5, area 6 to 20, and area 6 to 40 than control subjects. During the follow-up period, 29 patients met primary outcome. Age, slope 5, Area 6 to 20, Area 6 to 40, acute physiology and chronic health evaluation II score, multiple organ dysfunction score (MODS), logistic organ dysfunction score (LODS), and myocardial infarction history were significantly associated with primary outcome. Slope 5 showed the greatest discriminatory power. In a net reclassification improvement model, slope 5 significantly improved the predictive power of LODS; Area 6 to 20 and Area 6 to 40 significantly improved the predictive power in MODS. In an integrated discrimination improvement model, slope 5 added significantly to the prediction power of each clinical parameter. Area 6 to 20 and Area 6 to 40 significantly improved the predictive power in sequential organ failure assessment. Conclusions: MSsE provides additional prognostic information in patients receiving ECLS. Electronic supplementary material The online version of this article (doi:10.1186/s13054-014-0548-3) contains supplementary material, which is available to authorized users
Transcriptome analysis of Dnmt3l knock-out mice derived multipotent mesenchymal stem/stromal cells during osteogenic differentiation
Multipotent mesenchymal stem/stromal cells (MSCs) exhibit great potential for cell-based therapy. Proper epigenomic signatures in MSCs are important for the maintenance and the subsequent differentiation potential. The DNA methyltransferase 3-like (DNMT3L) that was mainly expressed in the embryonic stem (ES) cells and the developing germ cells plays an important role in shaping the epigenetic landscape. Here, we report the reduced colony forming ability and impaire
Clinical activity of ASP8273 in Asian patients with nonāsmallācell lung cancer with EGFR activating and T790M mutations
Epidermal growth factor receptor (EGFR)āactivating mutations confer sensitivity to tyrosine kinase inhibitor (TKI) treatment for nonāsmallācell lung cancer (NSCLC). ASP8273 is a highly specific, irreversible, onceādaily, oral, EGFR TKI that inhibits both activating and resistance mutations. This ASP8273 doseāescalation/doseāexpansion study (NCT02192697) was undertaken in two phases. In phase I, Japanese patients (aged ā„20 years) with NSCLC previously treated with ā„1 EGFR TKI received escalating ASP8273 doses (25ā600 mg) to assess safety/tolerability and to determine the maximum tolerated dose (MTD) and/or the recommended phase II dose (RP2D) by the Bayesian Continual Reassessment Method. In phase II, adult patients with T790Māpositive NSCLC in Japan, Korea, and Taiwan received ASP8273 at RP2D to further assess safety/tolerability and determine antitumor activity, which was evaluated according to Simon's twoāstage design (threshold response = 30%, expected response = 50%, Ī± = 0.05, Ī² = 0.1). Overall, 121 (n = 45 [33W/12M] phase I, n = 76 [48W/28M]) phase 2) patients received ā„1 dose of ASP8273. In phase I, RP2D and MTD were established as 300 and 400 mg, respectively. As 27 of the 63 patients treated with ASP8273 300 mg achieved a clinical response, ASP8273 was determined to have antitumor activity. The overall response rate at week 24 in all patients was 42% (n = 32/76; 95% confidence interval, 30.9ā54.0). Median duration of progressionāfree survival was 8.1 months (95% confidence interval, 5.6, upper bound not reached). The most commonly reported treatmentārelated adverse event in phase II was diarrhea (57%, n = 43/76). ASP8273 300 mg was generally well tolerated and showed antitumor activity in Asian patients with both EGFRāactivating and T790M mutations
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