Facile Synthesis of Zinc Indium Oxide Nanofibers Distributed with Low Content of Silver for Superior Antibacterial Activity

Exploring new antibacterial materials is of great significance for limiting the transmission of germs and protecting human health. Although Ag and oxide nanoparticles have both been extensively used in the field of antibacterial, it is still urgently need to figure out how to combine their characteristics for sterilization. Herein, ZnO/In2O3‐Ag nanofibers are prepared with uniformly dispersed Ag through a facile method of electrospinning and subsequent sintering. The obtained nanofibers are of high purity and have diameters from 90 to 110 nm. The silver is in a zero‐valent state, which is beneficial for sterilization. The quantitative test of bacterial activity shows that the nanofibers are bactericidal for both Staphylococcus aureus and Escherichia coli, with an especially strong inhibitory effect on E. coli. At relatively low concentrations, 98% of E. coli can be killed. Herein, light is shed on exploring more complexes of oxide nanomaterials and Ag for sterilization

Population dynamics of Agriophyllum squarrosum, a pioneer annual plant endemic to mobile sand dunes, in response to global climate change

Climate change plays an important role in the transition of ecosystems. Stratigraphic investigations have suggested that the Asian interior experienced frequent transitions between grassland and desert ecosystems as a consequence of global climate change. Using maternally and bi-parentally inherited markers, we investigated the population dynamics of Agriophyllum squarrosum (Chenopodiaceae), an annual pioneer plant endemic to mobile sand dunes. Phylogeographic analysis revealed that A. squarrosum could originate from Gurbantunggut desert since similar to 1.6 Ma, and subsequently underwent three waves of colonisation into other deserts and sandy lands corresponding to several glaciations. The rapid population expansion and distribution range shifts of A. squarrosum from monsoonal climate zones suggested that the development of the monsoonal climate significantly enhanced the population growth and gene flow of A. squarrosum. These data also suggested that desertification of the fragile grassland ecosystems in the Qinghai-Tibetan Plateau was more ancient than previously suggested and will be aggravated under global warming in the future. This study provides new molecular phylogeographic insights into how pioneer annual plant species in desert ecosystems respond to global climate change, and facilitates evaluation of the ecological potential and genetic resources of future crops for non-arable dry lands to mitigate climate change

Reduction of CuO into Cu with Guaiacol as a Model Compound of Lignin with a Homogeneous Catalyst of NaOH

The reduction of CuO with a lignin model compound, guaiacol, is investigated, to develop a new and green method for both Cu smelting and the utilization of lignin. The results showed that CuO can be completely reduced into Cu and guaiacol selectively converted to carboxylic acids such as fumaric, maleic, acetic, and formic acids at a mild temperature of 250 °C. The presence of NaOH has a significant effect on enhancing the reduction of CuO and the selective yield of carboxylic acids. Two possible reaction pathways were proposed for the reduction of CuO with guaiacol. One pathway involves the oxidative decomposition of guaiacol into carboxylic acids. The other reaction pathway proceeds with the polymerization of guaiacol into oligomers, which can be reused for CuO reduction due to their easy hydrolyzation to monomers under hydrothermal conditions

Development of a Lung Vacancy Mouse Model through CRISPR/Cas9-Mediated Deletion of Thyroid Transcription Factor 1 Exon 2

A developmental niche vacancy in host embryos is necessary for stem cell complementation-based organ regeneration (SCOG). Thyroid transcription factor 1 (TTF-1) is a tissue-specific transcription factor that regulates the embryonic development and differentiation of the thyroid and, more importantly, lungs; thus, it has been considered as a master gene to knockout in order to develop a lung vacancy host. TTF-1 knockout mice were originally produced by inserting a stop codon in Exon 3 of the gene (E3stop) through embryonic stem cell-based homologous recombination. The main problems of utilizing E3stop host embryos for lung SCOG are that these animals all have a tracheoesophageal fistula (TEF), which cannot be corrected by donor stem cells, and most of them have monolateral sac-like lungs. To improve the mouse model towards achieving SCOG-based lung generation, in this project, we used the CRISPR/Cas9 tool to remove Exon 2 of the gene by zygote microinjection and successfully produced TTF-1 knockout (E2del) mice. Similar to E3stop, E2del mice are birth-lethal due to retarded lung development with sac-like lungs and only a rudimentary bronchial tree, increased basal cells but without alveolar type II cells and blood vessels, and abnormal thyroid development. Unlike E3stop, 57% of the E2del embryos presented type I tracheal agenesis (TA, a kind of human congenital malformation) with a shortened trachea and clear separations of the trachea and esophagus, while the remaining 43% had TEF. Furthermore, all the E2del mice had bilateral sac-like lungs. Both TA and bilateral sac-like lungs are preferred in SCOG. Our work presents a new strategy for producing SCOG host embryos that may be useful for lung regeneration

majoradvancesinstudiesofthephysicalgeographyandlivingenvironmentofchinaduringthepast70yearsandfutureprospects

The natural environment provides material essentials for human survival and development. The characteristics, processes, regional differentiation and forcing mechanisms of the elements of the natural environment (e.g. geomorphology, climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective

Major advances in studies of the physical geography and living environment of China during the past 70 years and future prospects

The natural environment provides material essentials for human survival and development. The characteristics, processes, regional differentiation and forcing mechanisms of the elements of the natural environment (e.g. geomorphology, climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective