Effect of PVP Coating on LiMnBO3 Cathodes for Li-Ion Batteries

LiMnBO₃ is a potential cathode for Li-ion batteries, but it suffers from a low electrochemical activity. To improve the electrochemical performance of LiMnBO₃, the effect of polyvinyl pyrrolidone (PVP) as carbon additive was studied. Monoclinic LiMnBO₃/C and LiMnBO₃-MnO/C materials were obtained by a solid-state method at 500 °C. The structure, morphology and electrochemical behavior of these materials are characterized and compared. The results show that carbon additives and ball-milling dispersants affect the formation of impurities in the final products, but MnO is beneficial for the performance of LiMnBO₃. The sample of LiMnBO₃-MnO/C delivered a high capacity of 162.1 mAh g⁻¹ because the synergistic effect of the MnO/C composite and the suppression of the PVP coating on particle growth facilitates charge transfer and lithium–ion diffusion.     

A Nondestructive Technique to Determine the Rate of Oxygen Permeation into Solid Dosage Forms

The current study investigated the use of electron paramagnetic resonance (EPR) spectroscopy as a nondestructive method to quantify the partial pressure of oxygen (pO₂) in tablets and hard shell capsules. Lithium phthalocyanine crystals (LiPC) were placed inside the dosage forms. The peak-to-peak linewidth of the first derivative of the LiPC EPR spectra was measured and, by calibration tables, the oxygen partial pressure, pO₂, within the dosage form was determined. The intra-dosage form pO₂ was followed as a function of time after changing the exterior gas stream composition. Results showed initial oxygen concentrations comparable to atmospheric levels in all tablets and capsules investigated. Oxygen rapidly permeated into unsealed gelatin and cellulosic hard shell capsules. Banding at the cap/body joint significantly reduced the oxygen permeation rate. Oxygen also rapidly permeated into tablet compacts, regardless of the compressional force used during tableting, while application of a polymeric film significantly decreased the rate of oxygen permeation. This EPR technique was shown to be a suitable nondestructive method to study oxygen permeation kinetics in solid dosage forms.     

Film Growth Rates and Activation Energies for Core-Shell Nanoparticles Derived from a CVD Based Aerosol Process

Silica core-shell nanoparticles of about 60–120 nm with a closed outer layer of bismuth or molybdenum oxide of 1–10 nm were synthesized by an integrated chemical vapor synthesis/chemical vapor deposition process at atmospheric pressure. Film growth rates and activation energies were derived from transmission electron microscopy (TEM) images for a deposition process based on molybdenum hexacarbonyl and triphenyl bismuth as respective coating precursors. Respective activation energies of 123 ± 10 and 155 ± 10 kJ/mol are in good agreement with the literature and support a deposition mechanism based on surface-induced removal of the precursor ligands. Clean substrate surfaces are thus prerequisite for conformal coatings. Integrated aerosol processes are solvent-free and intrinsically clean. In contrast, commercial silica substrate particles were found to suffer from organic residues which hinder shell formation, and require an additional calcination step to clean the surface prior to coating. Dual layer core-shell structures with molybdenum oxide on bismuth oxide were synthesized with two coating reactors in series and showed similar film growth rates.     

Zero-order release of 5-fluorouracil from PCL-based films featuring trilayered structures for stent application

A trilayered Poly(ε-caprolactone) (PCL)-based film with a coating layer (CL), a drug-storing layer (DSL) loaded with antitumor drug 5-Fluorouracil (5-FU) and a backing layer (BL) are presented for film-based stent application in malignant stricture or stenosis. V-C diffusion cells were used to investigate the drug permeability of the CL, while scanning electron microscopy (SEM) was employed for observing the microscopic architectures and morphologies. Drug release from the trilayered films exhibited a zero-order pattern, and the release process followed an ‘outer-to-inner’ pattern. The formation mechanism and influencing factors of the zero-order drug release pattern were in-depth elucidated, and factors affecting the drug release were also investigated. The reduction of initial drug loading in DSL slowed the drug release and diminished the zero-order release pattern. Drug permeability of the CL depended significantly on CL thickness, but not significantly on PCL molecular weight. Besides, the addition of PEG porogen in the CL accelerated the drug release by elevation of the drug permeability of CL, and the action mechanism of PEG was revealed by the PEG release test and SEM. The loading of 5-FU in the CL could lead to a two-phased release profile. This study revealed the potential of the trilayered film in controlled drug delivery to intraluminal tumor due to its highly tunable zero-order drug release.     

Peri‐Implant Bone Density in Senile Osteoporosis‐Changes from Implant Placement to Osseointegration

Purpose: The aim of this study was to examine healing over time after implant body placement in a senile osteoporosis model and a control group. Materials and Methods: In this study, 16‐week‐old male mice were used. The senile osteoporosis model consisted of senescence‐accelerated prone 6 mice and the control group consisted of senescence‐accelerated resistant 1 mice. Titanium‐coated plastic implants were used as experimental implants whose dimensions were 3.0 mm in length, 1.1 mm in apical diameter, and 1.2 mm in coronal diameter. Bone samples were collected at 5, 7, 14, 21, and 28 days after implant placement. A micro‐quantitative computed tomography (QCT) system was used to scan these samples and a phantom in order to quantitate bone mineral measurements. Bone mineral density (BMD) of each sample was measured. Each sample was also examined by light microscopy after QCT imaging. At 14 and 28 days after implant placement, the bone‐implant contact (BIC) ratios were calculated from light microscopy images and were divided into cortical bone and bone marrow regions. Results: When BMD was compared between the osteoporosis and control groups using micro‐QCT, the osteoporosis group had a significantly lower BMD in the region 0–20 µm from the implant surface in the bone marrow region at 14 days onward after implant placement. Compared with the control group, the osteoporosis model also had significantly lower BMD in all regions 0–100 µm from the implant surface in the bone marrow region at 14 days after placement. However, in the cortical bone region, no statistically significant difference was observed in the regions at the bone‐implant interface. Light microscopy revealed osseointegration for all implants 28 days after implant placement. The osteoporosis model tended to have lower BICs compared with that of the control group, although this did not reach statistical significance. Discussion: Our results showed that osseointegration was achieved in the osteoporosis model. However, the BMD was 30–40% lower than that of the control group in the region closest to the implant surface in bone marrow region. Peri‐implant BMD was lower in a relatively large area in the osteoporosis model during an important time for osseointegration. Therefore, this result suggests that osteoporosis might be considered as a risk factor in implant therapy. Conclusion: The osteoporosis model had a lower BMD than the control group in the region closest to the implant during an important time for osseointegration. This result suggests that senile osteoporosis might be a risk factor in implant therapy. However, the osteoporosis model and the control group had no difference in peri‐implant BMD in the cortical bone region. This suggests that risk might be avoided by implant placement that effectively uses the cortical bone.     

Potential Role of EGF and EGFR in Tongue Coating Formation

Tongue coating, as a sensitive index of the physiological and pathological changes of human organs, is an important basis for the Traditional Chinese Medicine(TCM) syndrome differentiation and treatment. Mechanism of the formation and change of tongue coating is an important scientific problem. In recent years, researches indicated that in addition to apoptosis related genes, epidermal growth factor(EGF) and epidermal growth factor receptor(EGFR) also contribute to tongue coating formation. In this paper, we summarized recent studies on the potential role of EGF and EGFR in regulating the formation of tongue coating to provide some reference for the further investigations on tongue coating formation mechanisms.     

自制中药油外涂联合小牛血去蛋白提取物治疗放射性皮炎42例

目的:观察中药油外涂联合小牛血去蛋白提取物治疗放射性皮炎的临床疗效。方法:将本院2013年3月—2015年3月收治的放射性皮炎患者84例随机分为对照组和观察组各42例,对照组采用常规治疗,观察组采用中药油外涂联合小牛血去蛋白提取物治疗,比较两组患者临床疗效及疼痛缓解时间、皮肤愈合时间、疼痛缓解指标等。结果:观察组有效率为97.62%,显著优于对照组的64.28%,组间比较有统计学意义(P0.05);观察组疼痛缓解时间、皮肤愈合时间为(1.9±0.5)d、(3.8±1.7)d,显著优于对照组的(4.8±0.9)d、(8.8±2.3)d,组间比较,差异有统计学意义(P0.05);观察组疼痛缓解情况显著优于对照组,组间比较有统计学意义(P0.05)。结论:中药油外涂联合小牛血去蛋白提取物治疗放射性皮炎疗效显著,可明显改善患者的临床症状,缓解患者的皮肤不适感。     

Reduction in fat uptake of doughnut by microparticulated wheat bran

Wheat flour–microparticulated wheat bran (MWB) mixture and composites were prepared, and their potential as an oil repellent was evaluated in doughnuts. As MWB content increased, the oil-holding capacity decreased, and there were significant changes in water-holding capacity (p < 0.05). As MWB content increased, the fat content of doughnuts decreased. In addition, the wheat flour–MWB composite was more effective for preventing fat uptake than the wheat flour–MWB mixture. The hardness of the composite was higher than the mixture, although volume and weight decreased and surface colour became darker than that of the mixture. As the proportion of wheat bran in the doughnut formulation increased, the inner crust achieved a uniform cell size and cellular integrity was improved. Based on these data, wheat flour–MWB composites are appropriate for use in doughnut formulas with low fat uptake.