Observation on A-PRF promoting regeneration of osteochondral defects in rabbit knee joints

Objective·To explore the role of advanced platelet-rich fibrin (A-PRF) in osteochondral regeneration.Methods·Bone-marrow mesenchymal stem cells (BMSCs) and knee joint chondrocytes were obtained from New Zealand rabbits. A-PRF was obtained by low-speed centrifugation of the heart blood of rabbits. The histological structure of A-PRF was observed by an optical microscope. The release of growth factors in A-PRF was detected by ELISA, including platelet-derived growth factor, transforming growth factor-β, insulin-like growth factor, vascular endothelial growth factor, epidermal growth factor and fibroblast growth factor. A-PRF's cytotoxicity and capability for promoting the proliferation of rabbit BMSCs were detected by live/dead double staining and MTT methods. The effect of A-PRF on the gene expression of type Ⅱ collagen, aggrecan, alkaline phosphatase (ALP) and osteocalcin (OCN) in rabbit BMSCs was detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR). Transwell chambers were used to determine the effect of A-PRF on the migration ability of rabbit BMSCs and the chondrocytes. Rabbit knee osteochondral defect models were established, and 18 rabbits were randomly divided into 3 groups. The A-PRF group (n=6) was implanted with A-PRF in the defect, the A-PRF+BMSCs group (n=6) was implanted with rabbit BMSCs on A-PRF, and the control group (n=6) did not undergo implantation. The rabbits were sacrificed 12 weeks after surgery and the knee joint specimens were stained with hematoxylin-eosin (H-E), toluidine blue and safranin O/fast green. Based on the surface morphology and histology of the knee joints, the International Cartilage Repair Society (ICRS) scoring system was used for macroscopic and histological scoring.Results·A-PRF had a loose network structure and can slowly release growth factors. No cytotoxicity to rabbit BMSCs was observed after adding A-PRF, and the the capability for promoting the proliferation of rabbit BMSCs was significantly increased at 24, 48 and 72 h after adding A-PRF (all P<0.05). Chondrogenesis-related gene Ⅱ collagen and aggrecan, as well as osteogenesis-related genes ALP and OCN were significantly up-regulated (all P<0.05). After adding A-PRF, the migration abilities of rabbit BMSCs and chondrocytes were significantly enhanced (both P<0.05), and the migration ability of rabbit BMSCs was significantly higher than that of chondrocytes (P=0.025). The joint surface morphology in the rabbit knee joint defect models was observed. It can be seen that the defects in the A-PRF group and the A-PRF+BMSCs group were basically restored, while the the defects in the control group were only covered by soft tissue. In the ICRS macroscopic score, there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group, but the scores of the two groups were all significantly higher than those of the control group (all P<0.05). According to the histological results, both the A-PRF group and the A-PRF+BMSCs group formed osteochondral repair, but the cartilage in the A-PRF group was more mature, while the control group formed fibrous repair. In the ICRS histological score, there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group, but the scores of both the groups were significantly higher than those of the control group (both P<0.05).Conclusion·Autologous A-PRF has good biocompatibility and the capability for promoting the proliferation of BMSCs. It can promote the repair of cartilage and subchondral bone both in vitro and in vivo

The impact of different benefit packages of Medical Financial Assistance Scheme on health service utilization of poor population in Rural China

<p>Abstract</p> <p>Background</p> <p>Since 2003 and 2005, National Pilot Medical Financial Assistance Scheme (MFA) has been implemented in rural and urban areas of China to improve the poorest families' accessibility to health services. Local governments of the pilot areas formulated various benefit packages. Comparative evaluation research on the effect of different benefit packages is urgently needed to provide evidence for improving policy-making of MFA. This study was based on a MFA pilot project, which was one component of Health VIII Project conducted in rural China. This article aimed to compare difference in health services utilization of poor families between two benefit package project areas: H8 towns (package covering inpatient service, some designated preventive and curative health services but without out-patient service reimbursement in Health VIII Project,) and H8SP towns (package extending coverage of target population, covering out- patient services and reducing co-payment rate in Health VIII Supportive Project), and to find out major influencing factors on their services utilization.</p> <p>Methods</p> <p>A cross-sectional survey was conducted in 2004, which used stratified cluster sampling method to select poor families who have been enrolled in MFA scheme in rural areas of ChongQing. All family members of the enrolled households were interviewed. 748 and 1129 respondents from two kinds of project towns participated in the survey. Among them, 625 and 869 respondents were included (age≥15) in the analysis of this study. Two-level linear multilevel model and binomial regressions with a log link were used to assess influencing factors on different response variables measuring service utilization.</p> <p>Results</p> <p>In general, there was no statistical significance in physician visits and hospitalizations among all the respondents between the two kinds of benefit package towns. After adjusting for major confounding factors, poor families in H8SP towns had much higher frequency of MFA use (β = 1.17) and less use of hospitalization service (OR = 0.7 (H8SP/H8), 95%CI (0.5, 1.0)) among all the respondents. While calculating use of hospital services among those who needed, there was significant difference (p = 0.032) in percentage of hospitalization use between H8SP towns (46%) and H8 towns (33%). Meanwhile, the non-use but ought-to-use hospitalization ratio of H8SP (54%) was lower than that of H8 (67 %) towns. This indicated that hospitalization utilizations had improved in H8SP towns among those who needed. Awareness of MFA detailed benefit package and presence of physician diagnosed chronic disease had significant association with frequency of MFA use and hospitalizations. There was no significant difference in rate of borrowing money for illness treatment between the two project areas. Large amount of medical debt had strong association with hospitalization utilization.</p> <p>Conclusions</p> <p>The new extended benefit package implemented in pilot towns significantly increased the poor families' accessibility to MFA package in H8SP than that of H8 towns, which reduced poor families' demand of hospitalization services for their chronic diseases, and improved the poor population's utilization of out-patient services to some degree. It can encourage poor people to use more outpatient services thus reduce their hospitalization need. Presence of chronic disease and hospitalization had strong association with the presence of large amount of medical debt, which indicated that: although establishment of MFA had facilitated accessibility of poor families to this new system, and improved service utilization of poor families to some degree, but its role in reducing poor families' medical debt resulted from chronic disease and hospitalization was still very limited. Besides, the following requirements of MFA: co-payment for in-patient services, ceiling and deductibles for reimbursement, limitations on eligibility for diseases reimbursement, also served as most important obstacles for poor families' access to health care.</p> <p>Therefore, there is great need to improve MFA benefit package design in the future, including extending to cover out-patient services, raising ceiling for reimbursement, removing deductibles of MFA, reducing co-payment rate, and integrating MFA with New Rural Cooperative Medical Scheme more closely so as to provide more protection to the poor families.</p

Correction: Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies.

[This corrects the article DOI: 10.1371/journal.pone.0195659.]

Analysis of spatial–temporal evolution trends and influential factors of desert-oasis thermal environment in typical arid zone: The case of Turpan–Hami region

As a typical geographic landscape unit in the arid zone of northwest China, the distribution of the thermal environment in the substratum of the desert-oasis is of great significance to the monitoring of the ecological environment and the quality of human habitat in the region. The purpose of this research is to reveal the spatial–temporal evolution pattern of the thermal environment of the desert–oasis in the Turpan–Hami region from 2005 to 2020 and its trend changes, and to investigate the relationship between natural and human factors and the thermal environment and to conduct a long time series analysis. Firstly, the accuracy of MODIS land surface temperature (LST) data combined with site data was verified. Secondly, the mean-standard deviation method is used to identify desert heat island and oasis cold island zones. Again, the spatial–temporal distribution and change trends of thermal environment are explored by using standard deviation ellipse and spatial autocorrelation combined with land use/land cover (LULC) types. Finally, based on the multi-source remote sensing data, the natural factors and human factors are selected to explore their correlation with the thermal environment using Pearson correlation analysis. The results show that (1) the desert heat island zones are distributed in the desert areas on the periphery of urban built-up areas in Gaochang District, Shanshan County and Yizhou District of Hami Region. The oasis cold island zones are concentrated in the urban built-up areas of Gaochang District and Yizhou District, mainly because the vegetation coverage of urban built-up areas is higher than that of the peripheral desert areas. (2) The spatial development characteristics of the extremely high temperature (EHT) zone and the high temperature (HT)zone from 2005 to 2020 are “southeast-northeast-northwest” and “southeast-northwest” respectively, and the area of construction land 16a increased by 0.31%. This indicates that the spatial evolution of the thermal environment is closely related to the LULC and the degree of urbanization development. (3) From a four–period image with P  2.58, the thermal environment displays a high positive spatial correlation with Moran's I values of 0.45, 0.54, 0.47, and 0.45. (4) Temperature (Tem), downward longwave radiation (LWdown), and nighttime light intensity (NPP) all exhibited positive correlations with the LST and are significant in the desert region (p < 0.05); The albedo exhibited negative correlations with the LST and is significant in the grassland and woodland regions (p < 0.05)

A Tent Map Based A

Force and tactile sensors are basic elements for robot perception and control, which call for large range and high-accuracy amplifier. In this paper, a novel A/D conversion circuit for array tactile sensor is proposed by using nonlinear tent map phenomenon, which is characterized by sensitivity to small signal and nonlinear amplifying function. The tent map based A/D conversion circuits can simultaneously realize amplifying and A/D converting functions. The proposed circuit is not only simple but also easy to integrate and produce. It is very suited for multipath signal parallel sampling and A/D converting of large array tactile sensor

A Tent Map Based / Conversion Circuit for Robot Tactile Sensor

Force and tactile sensors are basic elements for robot perception and control, which call for large range and high-accuracy amplifier. In this paper, a novel / conversion circuit for array tactile sensor is proposed by using nonlinear tent map phenomenon, which is characterized by sensitivity to small signal and nonlinear amplifying function. The tent map based / conversion circuits can simultaneously realize amplifying and / converting functions. The proposed circuit is not only simple but also easy to integrate and produce. It is very suited for multipath signal parallel sampling and / converting of large array tactile sensor

Inflammatory markers in postoperative delirium (POD) and cognitive dysfunction (POCD): A meta-analysis of observational studies

<div><p>Background</p><p>The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD).</p><p>Methods</p><p>A systematic retrieval of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis.</p><p>Results</p><p>A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, <i>P</i> = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, <i>P</i> = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, <i>P</i> = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, <i>P</i> = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, <i>P</i> = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, <i>P</i> = 0.086, 16 studies).</p><p>Conclusion</p><p>Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral and cerebrospinal fluid (CSF) inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.</p></div

Meta-regression between the SMDs of peripheral CRP and IL-6 Levels before surgery and the potential sources of heterogeneity.

<p>Meta-regression between the SMDs of peripheral CRP and IL-6 Levels before surgery and the potential sources of heterogeneity.</p

IL-6 (Peripheral) levels before surgery in patients with POD (A) and POCD (B).

<p>IL-6 (Peripheral) levels before surgery in patients with POD (A) and POCD (B).</p

Egger’s test results for publication and selective reporting bias.

<p>Egger’s test results for publication and selective reporting bias.</p