Nanjing Library

Abstract: Policy document mention is considered to indicate the significance and societal impact of scientific product. However, the accuracy of policy document altmetrics data needs to be evaluated to fully understand its strength and limitation. An in-depth coding analysis was conducted on sample policy documents records of Altmetric.com database. The sample consists of 2079 records from all 79 distinct policy document source platforms tracked by the database. Errors about mentioned publications in the policy documents (type A error) are found in 8% of the records, while errors about either the recorded policy documents or the mentioned publications in the altmetrics database (type B error) are found in 70% of the records. In type B error, policy document link error (5% of the records) could be attributable to the policy document website, transcription error (52% of the records) could be attributable to the third-party bibliographic data provider. These two categories of error are relatively minor and may have limited influence on altmetrics research and practices. False positive policy document mention (13% of the records), however, could be attributable to the Altmetric database and may diminish the validity of research based on the policy document altmetrics data. The underlying reasons remain to be further investigated. Considering the high complexity of extracting mentions of publications from various sources and formats of policy documents as well as its short history, Altmetric database has achieved excellent performance.

Abstract: Abstract Embryo loss and pregnancy disorders are prevalent worldwide, with both conditions critically associated with dysfunctioning gastrulation processes. Gastrulation and post-gastrulation organogenesis are crucial stages of embryonic development that establish the blueprint for body part formation. These processes involve the sequential generation of three germ layer cells and primordial germ cells, as well as the assembly of the precursor tissues for body parts. However, due to ethical limitations associated with studying human embryogenesis, a more detailed understanding of gastrulation and post-gastrulation organogenesis remains elusive. To ensure that the knowledge obtained from gastruloids is biologically meaningful and clinically relevant, it is critical to create high-fidelity human embryo models that closely mimic embryogenesis in vivo . Here, we developed a two-stage derivation gastruloids in vitro based on human pluripotent stem cells. Morphological tracking mimicks the developmental processes of models from Carnegie Stage 4 (CS4) to early CS7. Our gastruloids exhibit key structures characteristic of human embryos, including amniotic cavity, embryonic disc, primitive streak, primary yolk sac, secondary yolk sac, and blood islets. Comparison of our cell lineage development maps showed that gastruloids closely resembled human natural CS7 gastrula. Our gastruloids exhibited transcriptional characteristics that mimicked the molecular pathways observed in natural embryos development. Importantly, we found that in our model, extraembryonic mesoderm originates from the yolk sac and primordial germ cells originate from the posterior epiblast of the embryonic disc. Moreover, we found that thalidomide affects the differentiation of three germ layer cells, resulting in the arrest of human gastruloid development. In conclusion, by establishing a human gastruloid, we were able to gain valuable insights into the mechanisms responsible for human gastrulation and shed light on the causes of early embryo loss and pregnancy disorders.

Abstract: Data accuracy is essential for reliable and valid altmetrics analysis. Although Twitter and Facebook altmetrics data are widely used for scholarly communication and scientific evaluation, few studies have tapped into their accuracy issue. Based on content analysis of random sample records over two phases, this study has investigated and compared the accuracy of Twitter and Facebook altmetrics data. Major conclusions are drawn as follows. (1) Three error types were identified from the altmetric data provider and six error types were identified from the altmetric data aggregator. Twitter and Facebook have shared most of the error types except for minor differences in the sub-categories. (2) The overall error rate is substantially high, being 17% and 32% for Twitter and Facebook respectively in April, 2019. However, except for publication date error and posting date error, the percentage of the other error types is relatively low (being around 3%). (3) The percentage of error types related to the dynamic nature of Twitter and Facebook is increasing over time, while percentage of error types concerning the bibliographic data is decreasing over time. (4) The error types are either “high seriousness low percentage” or “low seriousness high percentage”, therefore, they would probably not bring significant negative influence. (5) Underlying reasons of these error types are various. They could be attributable to the Twitter (or Facebook) user, Twitter (or Facebook) platform, altmetric database, as well as the third-party data provider. These results suggest that Twitter and Facebook altmetrics data in the Altmetric database are reliable on the whole, although there is still space for further improvement.

Abstract: Social inclusion is regarded as one of the missions of the public library.It has important influence for the public library to promote social harmony and realize the equality.