Preparation,characterization, and salicylic acid release behavior of chitosan/poly(vinyl alcohol) blend microspheres

Blend microspheres of chitosan (CS) with poly(vinyl alcohol) (PVA) were prepared as candidates for oral delivery system. CS/PVA microspheres containing salicylic acid (SA), as a model drug, were obtained using the coacervation‐phase separation method, induced by addition of a nonsolvent (sodium hydroxide solution) and then crosslinked with glutaraldehyde (GA) as a crosslinking agent. The microspheres were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy. Percentage entrapment efficiency, particle size, and equilibrium swelling degree of the microsphere formulations were determined. The results indicated that these parameters were changed by preparation conditions of the microspheres. Effects of variables such as CS/PVA ratio, pH, crosslinker concentration, and drug/polymer (d/p) ratio on the release of SA were studied at three different pH values (1.2, 6.8, and 7.4) at 37°C. It was observed that SA release from the microspheres increased with decreasing CS/PVA ratio and d/p ratio whereas it decreased with the increase in the extent of crosslinking. It may also be noted that drug release was much higher at pH 1.2 than that of at pH 6.8 and 7.4. The highest SA release percentage was obtained as 100% for the microspheres prepared with PVA/CS ratio of 1/2, d/p ratio of 1/2, exposure time to GA of 5 min, and concentration of GA 1.5% at the end of 6 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Profiling the Biological Characteristics and Transitions through Upper Tract Tumor Origin,Bladder Recurrence,and Muscle-Invasive Bladder Progression in Upper Tract Urothelial Carcinoma

To evaluate biological characteristics and transitions of upper tract urothelial carcinoma (UTUC) through metachronous bladder tumors after radical nephroureterectomy (RNU), we conducted immunohistochemical (IHC) staining of tumor specimens of UTUC tumor origin, non-muscle-invasive bladder cancer (NMIBC) and MIBC progressed after intravesical recurrence (IVR), and bladder primary MIBC. Fibroblast growth factor receptor 3 (FGFR3), p53, cytokeratin 5/6 (CK5/6), and CK20 were stained to examine expression rates. After expression assessment with heatmap clustering, the overexpression of four biomarkers from UTUC origin to metachronous MIBC progression was analyzed with clinicopathological variables. We found that high CK20 and low CK5/6 expression were both observed in UTUC tumor origin and subsequent NMIBC after RNU. By investigating molecular expression in the IVR specimen, we observed that low pT stage bladder recurrence occupied the majority of CK20 high CK5/6 low expression, but would change to CK20 low CK5/6 high expression as it progressed to MIBC. UTUC metachronous MIBC has different characteristics compared with bladder primary MIBC, which comprises favorable biological features such as high FGFR3 expression, and follows favorable prognosis compared to those without FGFR3 expression. The present study demonstrated that the biological characteristics of UTUC tumor origin shifts from luminal to basal-like features with progression to MIBC, but FGFR3 expression taken over from UTUC origin may comprise a favorable entity compared to primary MIBC.     

Micro- and nano-encapsulation of limonene and permethrin for mosquito repellent finishing of cotton textiles

Iranian Polymer Journal - The aim of this study was to prepare mosquito repellent textiles. To compare bio-based and synthetic mosquito repellent agents, limonene and permethrin were encapsulated...     

Deuterium retention in SiC coated graphite by D2+ implantation

The doped graphite tiles bolted to the active cooling heat sink, made of GBST1308 (1% B₄C, 2.5% Si, 7.5% Ti) coated with SiC, are now being used as the only plasma facing material (PFM) for the EAST device since the campaign of 2008. From the plasma density and fueling point of view, it is important to study thoroughly the hydrogen isotope retention in this kind of SiC-coated doped graphite. D₂⁺ implantations into the SiC coated doped graphite were performed at Shizuoka University. The chemical states of Si and C were studied by means of X-ray photoelectron spectroscopy (XPS), and the thermal desorption behavior of deuterium was analyzed by thermal desorption spectroscopy (TDS). It was found that deuterium was trapped by both C and Si in the SiC coatings. In the previous studies, Oya et al. reported the deuterium retention behavior in polycrystalline β-SiC. In this paper, difference of retention behavior in β-SiC and SiC coating will be also discussed.     

Measurement of deuterium and helium by glow-discharge optical emission spectroscopy for plasma–surface interaction studies

To examine the resolution of isotope analysis of hydrogen with glow-discharge optical emission spectroscopy (GDOES), depth profiles of hydrogen and deuterium in a H-containing Ta/D-containing Ti/Ni layered structure were measured. The depth profiles of deuterium could be measured with sufficient resolution in the presence of relatively large amounts of hydrogen and vice versa. In addition, measurements of depth profiles of He implanted in W at room temperature were also performed with Ne plasma. The intensity of the He emissions was sufficiently high at a fluence of 10²⁰ He m^?2 or higher. The depth profiles of He measured in this manner were in good agreement with the results of cross-sectional observations using a transmission electron microscope. Therefore, it was concluded that GDOES with Ne plasma is a promising technique for the depth profile analysis of plasma-facing materials and deposited layers formed on them.     

Patients'' views on residual blood use for research purposes

OBJECTIVE: This study assessed the effect of nocturnal hypoglycemia on well-being cerebral function, and physical fatigue the next day in 10 subjects with IDDM. RESEARCH DESIGN AND METHODS: After an exercise test to determine work-loads corresponding to 30 and 60% VO2max, volunteers were studied twice, 4 weeks apart. Blood glucose was lowered one night to 2.3-2.7 mmol/l for 1 h, and at the control visit, hypoglycemia was avoided. The next morning, well-being was assessed using the minor symptom evaluation profile (MSEP), and cerebral function was assessed with the paced auditory serial addition test, the digit symbol substitution test, trail making part B, four-choice reaction time, and auditory P300 latency. Subjects then exercised at predetermined workloads corresponding to 30% VO2max for 30 min and 60% VO2max until exhaustion. Fatigue was assessed every 10 min using the Borg scale for rating of perceived exertion. RESULTS: All three components of the MSEP scored higher (indicating more symptoms) after the hypoglycemic night compared with the control night (P < 0.01 contentment, sleep; P < 0.001 vitality). None of the cerebral function tests performed the next day was affected by hypoglycemia. Exercise capacity was similar at both visits, but subjects were more fatigued after the hypoglycemic night (P < 0.01, analysis of variance). There were no differences in potassium, catecholamine, glucose, or lactate concentrations between visits either before or during exercise. CONCLUSIONS: One hour of hypoglycemia at night affects a subject's sense of well-being, but not cerebral function, the next day. The greater fatigue after the hypoglycemic night cannot be explained by the biochemical parameters measured.