[International focuses in the studies of chronic pelvic pain syndrome: A social network analysis].

OBJECTIVE: To analyze the internationally published literature relevant to chronic pelvic pain syndrome (CPPS) using bibliometrics and social network analysis, and investigate the current status and focuses of CPPS studies. METHODS: We identified 692 publications on CPPS by searching PubMed up to December 2015, extracted their subject headings, calculated the frequencies of the headings, and constructed a co-occurrence network of the high-frequency (≥10) subject headings. Then we studied the features and structure of the co-occurrence network by analyzing its attributes and topological structure. RESULTS: The density of the constructed co-occurrence network was 0.111, with an average distance of 2.886 and a clustering coefficient of 0.685. Its low density, long average distance and high clustering coefficient indicated that it was a sparse network, with a slow speed of information spreading among nodes but a strong potential coherence, which suggested that the current topics in the study of CPPS were scattered and weakly correlated, with a high possibility of being integrated. Based on the topological structure of the co-occurrence network, the topics in the study of CPPS were divided into six aspects: diagnosis and classification, drug therapy, treatment, etiology, microbiology, psychology, and epidemiology, the more important of which were diagnosis and classification, drug therapy, treatment and etiology. CONCLUSIONS: A system has been formed in the studies of CPPS, focusing on the diagnosis, drug therapy, and etiology of the disease. However, the research topics are relatively scattered and frequently repeated. Therefore, more attention should be paid to the macrocosmic guidance and rational coordination of the researches on CPPS.

[A bibliometric investigation to research fronts of major sub-specialties in internal medicine].

OBJECTIVE: To outline the research fronts of ten major sub-specialties in internal medicine. METHODS: Based on their impact factor scores and the proportion of the journals of 10 subspecialties (endocrinology & metabolism, cardiac & cardiovascular systems, hematology, infectious diseases, nephrology, gastroenterology & hepatology, respiratory system, rheumatology, critical care medicine, clinical neurology) in Journal Citation Report (JCR), and careful consulation of expert clinicians, we identified 50 journals. Their bibliographic records (including references) published in 2011 were downloaded, and the frequency of the references (citations) in each sub-specialty was counted and the highly cited records were extracted. We performed a clustering analysis according to the co-cited times among any pairs of the highly cited records. To tag each cluster of highly cited records, we browsed the titles and abstracts of all highly cited records in the same cluster, and concluded the main topics of each cluster. Finally, we extracted the current published papers devoted to particular cluster by some clustering analysis indicators. The clusters of highly cited records were considered as the intelligence base, and the main topics in current papers which citing these highly cited papers were considered as research fronts. RESULTS: Totally 50 journals on 10 sub-specialties in internal medicine were identified. A total of 202 highly cited papers, 38 clusters (knowledge bases) , and 152 corresponding current citing papers presenting the research fronts were selected. CONCLUSIONS: We confirm and present research fronts in 10 major sub-specialties of internal medicine. This study provides a synchronic structure of contemporary research activities in internal medicine sub-specialties.

Tantalum-coated pedicle screws enhance implant integration.

Because titanium alloy (Ti) has the natural advantage of a low elastic modulus, it has become the most commonly used material for the manufacturing of pedicle screws. However, its poor shear strength and osteogenic ability are undesirable properties. The superior osteoinductivity demonstrated by tantalum (Ta) in oral and maxillofacial surgery and joint surgery leads us to assume that the tantalum-coated pedicle screws may have better osteogenic properties and bone anchoring strength. To verify this hypothesis, MC3T3-E1 cells and human mesenchymal stem cells (hBMSCs) were seeded on the surface of Ta and Ti disks to compare the effects of two different metals on cell adhesion, proliferation, and differentiation. At the same time, we observed the inhibitory effect of Ta on osteoclasts. As an in vivo study, conventional Ti pedicle screws and Ta-coated screws were implanted in bilateral pedicles of Bama pigs. The results showed that compared to titanium, tantalum promoted greater cell adhesion and proliferation and improved the level of hBMSC mineralization, and Ta-coated screws exerted an inhibitory effect on osteoclasts. More importantly, we found that the effect of tantalum on osteogenic differentiation was mediated through the Wnt/ß-catenin and TGF-ß/smad signaling pathways. Ta-coated screws significantly promoted trabecular bone growth compared with Ti as evidenced by micro-CT, histology and biomechanical examination. Our study clearly indicated that tantalum was a superior promoter of osteogenesis and proved that tantalum coating is an effective improvement for titanium alloy implants.