BackgroundWe present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development.ResultsThe genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements.ConclusionsAnalyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution.

Metallic transition metal dichalcogenides (TMDs) have exhibited various exotic physical properties and hold the promise of novel optoelectronic and topological devices applications. However, the synthesis of metallic TMDs is based on gas-phase methods and requires high-temperature condition. As an alternative to the gas-phase synthetic approach, lower temperature eutectic liquid-phase synthesis presents a very promising approach with the potential for larger-scale and controllable growth of high-quality thin metallic TMD single crystals. Here, the first realization of low-temperature eutectic liquid-phase synthesis of type-II Dirac semimetal PtTe 2 single crystals with thickness ranging from 2 to 200 nm is presented. The electrical measurement of synthesized PtTe 2 reveals a record-high conductivity of as high as 3.3 × 10 6 S m −1 at room temperature. Besides, the weak antilocalization behavior is identified experimentally in the type-II Dirac semimetal PtTe 2 for the first time. Furthermore, a simple and general strategy is developed to obtain atomically thin PtTe 2 crystal by thinning as-synthesized bulk samples, which can still retain highly crystalline and exhibits excellent electrical conductivity. The results of controllable and scalable low-temperature eutectic liquid-phase synthesis and layer-by-layer thinning of high-quality thin PtTe 2 single crystals offer a simple and general approach for obtaining different thickness metallic TMDs with high meltingpoint transition metal.

Background With the development of medicine, new teaching methods, such as flipped classroom and problem-based learning (PBL), have received much attention in medical education. However, the implementation of flipped classroom combined with PBL in endocrinology education has not been well investigated. Considering that both two teaching methods may complement each other, therefore, the aim of this study was to evaluate students’ learning effectiveness acceptability of the pedagogy between traditional lecture-based teaching methods and the combination of flipped classrooms with PBL teaching methods in the endocrinology internship. Methods 74 fourth-year medical students at the Bengbu Medical College were enrolled in the endocrinology internship. Hyperthyroidism was chosen for the content of this study. The participants were randomly allocated into either the combination group of flipped classroom with PBL (CG) or the traditional lecture-based classroom group (TG). Both a pre-quiz and a post-quiz were conducted before and after the classes, respectively. All questions in the quizzes were classified into two aspects, basic theoretical knowledge and clinical case analyses based on the Bloom’s Taxonomy. The scores were compared and students were required to complete the questionnaire to evaluate their perceptions and experience. Results The mean post-quiz scores of both the TG and the CG were higher than those of the pre-quiz. Additionally, the post-quiz showed that students in the CG had significantly higher scores in the TG. Further analysis found that after class, only the difference in clinical case analysis between CG and TG was significant. The scores of all items in the questionnaires were higher in the CG than in the TG. More students agreed that the combined teaching method could help to improve their performance, at the same time, it could increase their workload. Conclusions The combination of the flipped classroom and PBL teaching approach could be a better option over the traditional lecture-based classroom in the teaching of hyperthyroidism during endocrinology internship, although it can increase students’ workload. To be widely accepted and implemented, further optimizations are required.

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