Modular stem in total hip arthroplasty for patients with trochanter valgus deformity: surgical technique and case series.

BACKGROUND: Trochanter valgus deformity (TVD) is a rare condition of total hip arthroplasty (THA). Femoral osteotomy could be required in correcting the deformity to implant femoral stem in severe TVD. In this study, we described one unpublished technique of reverse sleeve of S-ROM to get through the complex situation. This study aimed to summarize and evaluate its technical challenges, safety and effectiveness. METHODS: From January 2006 to December 2014, we enrolled patients whose sleeves were implanted towards the great trochanter in THA with TVD. Their demographics, perioperative and postoperative information were recorded. To explore its indication, we measured and analyzed the ratio of greater trochanter/lesser trochanter (G/L ratio) and trochanter valgus angle (TVA). RESULTS: Twelve patients (1 male and 11 female, average age 42.30 ± 10.23) had mean follow-up of 6 years. Among them, only two patients had intraoperative femoral fracture. The survivorship of femoral prosthesis was 100%. The Harris hip score (HHS) increased from preoperative 34.31 ± 14.43 to postoperative 84.12 ± 11.33. All patients\u27 G/L ratio were larger than 1.50. CONCLUSIONS: The reverse sleeve of S-ROM was a reliable method for the patients with severe TVD, which brought satisfying clinical outcomes in mid-term follow-up

Geranylgeranyltransferase I is essential for dendritic development of cerebellar Purkinje cells

<p>Abstract</p> <p>Background</p> <p>During cerebellar development, Purkinje cells (PCs) form the most elaborate dendritic trees among neurons in the brain, but the mechanism regulating PC arborization remains largely unknown. Geranylgeranyltransferase I (GGT) is a prenyltransferase that is responsible for lipid modification of several signaling proteins, such as Rho family small GTPase Rac1, which has been shown to be involved in neuronal morphogenesis. Here we show that GGT plays an important role in dendritic development of PCs.</p> <p>Results</p> <p>We found that GGT was abundantly expressed in the developing rat cerebellum, in particular molecular layer (ML), the region enriched with PC dendrites. Inhibition or down-regulation of GGT using small interference RNA (siRNA) inhibited dendritic development of PCs. In contrast, up-regulation of GGT promoted dendritic arborization of PCs. Furthermore, neuronal depolarization induced by high K⁺or treatment with brain-derived neurotrophic factor (BDNF) promoted membrane association of Rac1 and dendritic development of PCs in cultured cerebellar slices. The effect of BDNF or high K⁺was inhibited by inhibition or down-regulation of GGT.</p> <p>Conclusion</p> <p>Our results indicate that GGT plays an important role in Purkinje cell development, and suggest a novel role of GGT in neuronal morphogenesis <it>in vivo</it>.</p

Antibacterial activities of gold and silver nanoparticles against Escherichia coli and bacillus Calmette-Guérin

BACKGROUND: Diseases such as tuberculosis (TB) have always had a large impact on human health. Bacillus Calmette-Guérin (BCG) is used as a surrogate for TB during the development of anti-TB drugs. Nanoparticles (NPs) have attracted great interest in drug development. The purpose of this study was to examine the potential of NPs as anti-TB compounds by studying the interacting mechanisms between NPs and bacteria. RESULTS: We investigated effects of gold and silver NPs on BCG and Escherichia coli. Experimentally, particle size and shape were characterized using transmission electron microscopy (TEM). Different concentrations of NPs were applied in bacterial culture. The growth of E. coli was monitored through colony forming units (CFU). The mechanism of interaction between NPs and bacteria was analyzed through bacterial thin sections followed by TEM and scanning electron microscopy. Antibacterial effects on BCG were observed by recording fluorescent protein expression levels. CONCLUSIONS: The results suggest NPs have potential applications as anti-TB compounds. The antibacterial effects and mechanism of action for NPs were dependent upon composition and surface modifications

International Research Progress on Encapsulation and Release of Flavor Substances by Starch-based Wall Materials

The entrapment and release of flavor substances is a frontier topic in the field of food flavor research. This paper mainly reviews the research progress on the entrapment and release of flavor substances based on starch-based wall materials. Starch-based wall material refers to a kind of natural polymer material which uses starch or its derivatives to cover fat-soluble components through its hydrophobic cavity. This paper mainly focuses on the methods and classification of hydrolysis， physical modification and chemical modification of starch-based wall materials， molecular dynamics simulation of non-covalent interaction between starch and flavor substances， preparation and structural characterization of starch-based flavor microcapsules， starch-based flavor microcapsules release process， influencing factors， flavor release mechanism (diffusion， erosion， degradation， swelling， melting， etc.). And the application of starch-based flavor microcapsules was reviewed. In order to have a comprehensive understanding of the domestic and foreign research progress on the entrapment and release of flavor substances in starch-based wall materials，and provide certain theoretical and practical references for the development of starch-based flavor materials

Ultra-high strength metal matrix composites (MMCs) with extended ductility manufactured by size-controlled powder and spherical cast tungsten carbide

The main challenge of particle reinforced metal matrix composites (MMCs) is balancing strength and ductility. This research uses type 420 stainless steel and spherical cast tungsten carbide (WC/W2C) with a similar powder size and range as raw powders to manufacture laser powder bed fusion (LPBF) 420 + 5 wt% WC/W2C MMCs. LPBF 420 + 5 wt% WC/W2C MMCs contain austenite, martensite, and W-rich carbides (WC/W2C, FeW3C, M6C, and M7C3) from nanometre to micrometre scale. The well-balanced composition creates a crack-free reaction layer between the reinforced particles and matrix. This reaction layer consists of two distinct layers, depending on the element concentration. The LPBF 420 + 5 wt% WC/W2C MMCs achieved an excellent compressive strength of ∼5.5 GPa and a considerable fracture strain exceeding 50 %. The underlying mechanisms for the improved mechanical properties are discussed, providing further insight to advance the application of MMCs via additive manufacturing