Engineering new bone tissue in vitro on highly porous poly(Α-hydroxyl acids)/hydroxyapatite composite scaffolds

Engineering new bone tissue with cells and a synthetic extracellular matrix (scaffolding) represents a new approach for the regeneration of mineralized tissues compared with the transplantation of bone (autografts or allografts). In the present work, highly porous poly( L -lactic acid) (PLLA) and PLLA/hydroxyapatite (HAP) composite scaffolds were prepared with a thermally induced phase separation technique. The scaffolds were seeded with osteoblastic cells and cultured in vitro . In the pure PLLA scaffolds, the osteoblasts attached primarily on the outer surface of the polymer. In contrast, the osteoblasts penetrated deep into the PLLA/HAP scaffolds and were uniformly distributed. The osteoblast survival percentage in the PLLA/HAP scaffolds was superior to that in the PLLA scaffolds. The osteoblasts proliferated in both types of the scaffolds, but the cell number was always higher in the PLLA/HAP composite scaffolds during 6 weeks of in vitro cultivation. Bone-specific markers (mRNAs encoding bone sialoprotein and osteocalcin) were expressed more abundantly in the PLLA/HAP composite scaffolds than in the PLLA scaffolds. The new tissue increased continuously in the PLLA/HAP composite scaffolds, whereas new tissue formed only near the surface of pure PLLA scaffolds. These results demonstrate that HAP imparts osteoconductivity and the highly porous PLLA/HAP composite scaffolds are superior to pure PLLA scaffolds for bone tissue engineering. © 2000 John Wiley & Sons, Inc. J Biomed Mater Res 54: 284–293, 2001Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34419/1/16_ftp.pd

Meta-analysis Followed by Replication Identifies Loci in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as Associated with Systemic Lupus Erythematosus in Asians

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic involvement and ethnic differences. Susceptibility genes identified so far only explain a small portion of the genetic heritability of SLE, suggesting that many more loci are yet to be uncovered for this disease. In this study, we performed a meta-analysis of genome-wide association studies on SLE in Chinese Han populations and followed up the findings by replication in four additional Asian cohorts with a total of 5,365 cases and 10,054 corresponding controls. We identified genetic variants in or near CDKN1B, TET3, CD80, DRAM1, and ARID5B as associated with the disease. These findings point to potential roles of cell-cycle regulation, autophagy, and DNA demethylation in SLE pathogenesis. For the region involving TET3 and that involving CDKN1B, multiple independent SNPs were identified, highlighting a phenomenon that might partially explain the missing heritability of complex diseases

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe

A Study on the Analysis of the Effects of Passenger Ship Abandonment Training Using VR

Virtual reality (VR) has been adopted for education and training in numerous lines of work. In the field of maritime education and training (MET), training with VR has been implemented in areas such as engine room system familiarization, dangerous work onboard familiarization, and emergency response. In addition, in line with current trends in maritime autonomous surface ship (MASS) technology developments, trial applications of VR have been implemented to understand the applicability of this type of vessel. Moreover, there is an increasing need to reinforce education/training in MET to reduce ship accidents. The purpose of this study is to investigate the level of satisfaction with VR education/training, the impact of that education, and matters requiring training emphasis for implementation. To this end, the training participants’ satisfaction with VR training was compared to that of video training, and items of strategic importance in the training content were identified using Borich’s needs assessment, after which the educational impact of VR training was compared to that of video training. The results of this study are expected to contribute to the extended application of MET using VR, and can help in identifying areas for emphasis in training to reduce maritime accidents

Sintering behavior of U-80 at.%Zr powder compacts in a vacuum environment

Sintering behavior of U-80 at.%Zr powder compacts in a temperature range from 1100 to 1500 ??C in a vacuum of 1 ?? 10-4 Pa was evaluated. The sintered density depended more on the sintering temperature than on the sintering time. The sintered specimens consisted of the ??-UZr2 matrix with acicular ??-Zr precipitates, but it still had un-reacted zirconium when the sintering temperature was 1100 ??C. The uranium depletion near the surface of the specimens sintered at temperatures above 1300 ??C was detected. Massive Zr(O) grains in the sintered specimen were found, and their formation was restrained when the cooling rate from the sintering temperature was increased.close1

3、40年代的香港文化

主題詳情: 陳智德：五四新文學與香港新詩 李世莊：三○年代兩位本地青年藝術家—王少陵與陳福善 黃淑嫺：三四○年代香港詩人與電