Controllable one-pot synthesis of uniform colloidal TiO2 particles in a mixed solvent solution for photocatalysis.

This study reports on the controllable synthesis of uniform colloidal titanium dioxide (TiO2) particles and their photocatalytic applications toward rhodamine B (RhB) degradation. The monodispersed TiO2 particles were synthesized under mixed solvent conditions by sol-gel chemistry in a one-pot process. Varying the ratio of solvent composition, the concentration of surfactant and TiO2 precursor was used to control the particle diameter, degree of monodispersity and morphology. The modification of the calcination temperature affected the crystallinity and crystalline phase of the colloidal TiO2 particles. When uniform, amorphous TiO2 particles were calcined at an optimal temperature (500 °C), the final sample exhibited beneficial characteristics such as high anatase crystallinity with a mixed phase of anatase and rutile and relatively high surface area. The photocatalytic efficiency of the uniform TiO2 sample with high anatase crystallinity with mixed phase and high surface area was dramatically enhanced towards RhB degradation under UV-vis irradiation. We systemically discuss the relationship between the synthetic parameters in our synthesis and the properties of the final TiO2 products, as well as the crystalline properties and performance enhancement of TiO2 photocatalysts calcined at different temperatures.

Catalytic behavior of Sn/Bi metal powder in anhydride-based epoxy curing.

In this paper, we report the catalytic activity of the Sn/Bi alloy beads and its acceleration of the exothermic epoxy curing reactions in various thermal conditions and bead compositions. As being used as low-melting solder balls in electronic interconnection processes with various epoxy systems, it was found that the Sn/Bi beads substantially lowered the exothermic peak temperature of the diglycidyl ether of bisphenol A (DGEBA)/anhydride systems in up to ca. 140 degrees C depending on different types of anhydride curing agents. The catalytic activation of Sn/Bi powder was initiated with a small amount of Sn/Bi powder, for example, lowering ca. 50 degrees C of the exothermic peak temperature by adding only 0.1 vol% of Sn/Bi powder. The catalytic capability of the powder was increased by using smaller sized beads corresponding to larger catalytic surface area at the same volume fraction. Exhibiting a latent catalytic effect, the catalytic activity of Sn/Bi powder was remained latent at temperatures lower than 100 degrees C in isothermal conditions.

[Correlation between clinical symptoms and radiologic findings before and after pneumatic balloon dilatation for achalasia].

BACKGROUND/AIMS: We investigated the risk factors for short-term recurrence and analyzed the correlation between subjective clinical symtoms and objective radiological findings in patients with achalasia undergoing pneumatic balloon dilatation. METHODS: Twenty patients who were treated by pneumatic balloon dilatation were enrolled. We compared prospectively various indices before and after the treatment as follows: 1) Eckardt symptom score and dysphagia grade, 2) The ratio of the maximal width in mid-esophageal lumen to the minimal width in distal esophagus around lower esophageal sphincter, and 3) the percentage of maximum activity retained in the esophagus at 30 seconds and T in esophageal scan two days after the treatment. RESULTS: 1) Clinical indices and radiologic indices significantly improved after pneumatic dilatation. 2) There was no significant correlation between the clinical indices and the radiologic indices before and after the treatment. 3) The difference percentage of clinical indices did not show significant correlation with the difference percentage of the radiologic indices. 4) Compared to the group above 20% in the difference percentage of 30 second residual fraction, the one below 20% had a four-fold risk in short-term recurrence. CONCLUSIONS: Clinical symptoms and radiologic indices significantly improve after pneumatic dilatation but have no significant correlation to each other. The group below 20% in the difference percentage of 30 second residual fraction has a high risk of recurrence and may need careful examination and early repeated pneumatic dilation.

Hematochezia with colonic polypoid angiodysplasia in a young female patient.

A 18-year-old girl visited the hospital due to hematochezia. Colonoscopy revealed a 6-mm Yamada type II polyp with stigmata of bleeding, and a shallow ulcer on top was found at the cecum base. The polyp was removed by snare polypectomy, and hematochezia stopped thereafter. Angiodysplasia was diagnosed histopathologically. Generally, angiodysplasia appears as a flat or elevated, bright-red lesion on endoscopy, with a polypoid shape being extremely rare. This case is significant because the lesion occurred at the youngest reported age and was the smallest that has been reported, and is the only polypoid arteriovenous malformation to be discovered in the cecum.

Clinical significance of insulin receptor substrate-I down-regulation in non-small cell lung cancer.

Insulin receptor substrate-1 (IRS-1) is an adaptor protein for insulin-like growth factor (IGF) signaling and it is presumed associated with cancer development, progression or clinical outcome of patients harboring solid tumors. Therefore, we investigated by immunohistochemistry, the expression of IRS-1 in the tumor tissues from 94 patients who were diagnosed as stage I non-small cell lung cancer (NSCLC) and had undergone a curative lung resection. The relationships between its intratumoral expression and various clinical parameters were explored. IRS-1 is consistently expressed in the cytoplasm of intrapulmonary bronchial and bronchiolar epithelial cells comprising normal appearing adjacent lung tissues. Forty-one (43.6%) of 94 specimens showed loss of IRS-1 expression. In a subset analysis, IRS-1 was more frequently lost in stage IB than in IA tumors (50.0 vs. 22.7%, p=0.024, chi(2) test), which was reflected by the facts that tumors which showed down-regulation of IRS-1 had larger area than those with IRS-1 expression (18.1 vs. 12.1 cm(2), p=0.044, t-test). Down-regulation of IRS-1 is more frequently observed in squamous cell carcinoma than other cell type lung cancer (p=0.002, chi(2) test) and its expression was not affected by histological grade of differentiation. Comparing pack-years (P.Y.) between groups of smokers whose tumor expressed IRS-1 and those that did not, smokers whose tumor showed loss of IRS-1 expression had higher P.Y. than those whose tumor did express IRS-1 (39.2+/-23.67 vs. 25.6+/-26.61 P.Y., p=0.034, t-test). Intratumoral expression of IRS-1 did not influence disease-free survival, disease-specific survival or overall survival of stage I NSCLC patients, whose median follow-up duration is 7.5 years (95% CI; 7.21-7.86 years). These results suggest that loss of IRS-1 might rather be an early event in NSCLC development than a prognostic factor and that it is more strongly related with squamous cell carcinoma and with smoking.

[The effects of probiotics on symptoms of irritable bowel syndrome].

BACKGROUND/AIMS: Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) tract disorder that has heterogeneous clinical presentations such as abdominal pain, diarrhea, constipation, and abdominal distension. It is known that several mechanisms are involved in the pathogenesis of IBS. Probiotics may target one or more pathophysiologic pathways in IBS and may improve the symptoms of IBS. However, the results of studies about probiotics on IBS are controversial. Therefore, the aim of this study was to evaluate the effect of probiotics on GI symptoms and intestinal gas volume changes in patients with IBS. METHODS: Forty patients were randomly allocated to be treated with Medilac DS (Bacillus subtilis, Streptococcus faecium) (n=20) or placebo (n=20) in a double-blind, prospective manner. The change in intestinal gas volume and symptom scores after 4-week treatment were evaluated for the efficacy. RESULTS: There was no significant difference in bloating, frequency of gas expulsion, frequency of defecation, and hardness of stool before and after the treatment. However, the severity of abdominal pain and the frequency of abdominal pain decreased significantly in Medilac DS group (2.4+/-1.3 cm/day --> 1.6+/-1.6 cm/day, 1.7+/-1.3/day --> 1.0+/-1.0/day) (p=0.044, p=0.038), but not in placebo group (2.1+/-2.0 cm/day --> 1.8+/-2.1 cm/day, 1.3+/-1.2/day --> 1.4+/-1.9/day). In both groups, intestinal gas volume at baseline, after 2-week treatment, and after 4-week treatment did not show significant change. Medilac DS was well tolerated without adverse events. CONCLUSIONS: Medilac DS is a safe and useful probiotic agent for the treatment of abdominal pain in patients with IBS.