Using Geneswitch technolgy to teach sex differentiation for undergraduates

The development and evaluation of a two-session laboratory class, based on Geneswitch technology and sex determination in the fruit fly Drosophila melanogaster, is described. Geneswitch system allows conditional control of gene expression. A laboratory exercise has been devised for sophomores in order to illustrate how Geneswitch technology can be used to conditionally over-express the key sex determination gene transformer (tra) during development, and how this inhibits sexual differentiation in males, resulting in a lack of much of the external genitalia and a reduction in the size of the sex combs. The protocol is inexpensive and straightforward, at the meantime gives students a good understanding of how molecular biology technologies can change biological processes including development.     

濒危植物永瓣藤叶片功能性状对环境因子的响应

植物叶片功能性状能够响应环境条件的变化，反应了植物对环境的适应策略。当前，针对藤本植物叶片功能性状地理格局及其环境驱动力的研究较少。以国家重点保护植物永瓣藤（Monimopetalum chinense）为研究对象，对其分布区内11个种群的15个叶片功能性状进行测量，并结合气候、土壤因子来解释叶性状变异。比较叶片性状在局域和区域尺度上的种内变异程度，利用多元逐步回归分析环境因子对叶性状的影响。结果表明，在局域尺度上，永瓣藤叶功能性状变异系数介于3.0%-22.5%，其中，叶面积变异程度最大，叶片碳含量变异最小。永瓣藤叶片形状随纬度上升而变得宽且圆。叶片磷含量相对较低，永瓣藤的生长可能受到了磷限制。土壤与气候因子是叶片性状的重要驱动因素，解释了25%-97%的叶片性状变异。在温度和水分充足的情况下，永瓣藤叶片趋向于的慢速生长的保守策略。总体来说，永瓣藤叶片功能性状通过一定的种内变异和性状组合，并与气候、土壤因子相互作用，适应当前的环境条件。     

Ant assemblage composition explains high predation pressure on artificial caterpillars during early night

1. Predator–prey interactions, especially those involving herbivorous insects, are of great importance in maintaining biodiversity. Predation pressure varies temporally in response to prey availability and activity. However, little is known about the patterns and drivers of fluctuations in predation pressure at fine temporal scales. 2. Artificial caterpillars (placed on plant leaves at breast height) were used to assess changes in predation pressure across four time intervals of the day in a monsoonal tropical rainforest in south-west China. The study examined how assemblage composition of arboreal ants, the dominant predators, changed across the same time intervals. The potential linkages between biotic (arboreal ants) and abiotic (temperature and light intensity) factors with predation rate were evaluated. 3. Predation rate on caterpillars during the early part of the night (19.00–01.00 hours) was significantly higher than in the morning, afternoon, or late night. Ant assemblage composition, rather than species richness or total abundance, best explained the variations in predation rate on artificial caterpillars. 4. The results help to strengthen understanding of trophic interactions by demonstrating that predation pressure fluctuates at finer timescales than previously tested, and that a particular set of ant species may play major roles in predation on caterpillars and possibly other organisms.     

Synergistic effect on anti-methicillin-resistant Staphylococcus aureus among combinations of α-mangostin-rich extract,lawsone methyl ether and ampicillin

α-Mangostin-rich extract (AME) exhibited satisfactory inhibitory activities against all tested MRSA strains, with minimum inhibitory concentrations (MICs) of 7·8–31·25 µg ml⁻¹, whereas lawsone methyl ether (LME) and ampicillin revealed weak antibacterial activity with MICs of 62·5–125 µg ml⁻¹. However, the combination of AME and LME showed synergistic effects against all tested MRSA strains with fractional inhibitory concentration index (FICI) values of 0·008–0·009, while the combination of AME and ampicillin, as well as LME and ampicillin produced synergistic effects with FICIs of 0·016–0·257. A time-kill assay against MRSA (DMST 20654 strain) revealed a 6-log reduction in CFU per ml, which completely inhibited bacterial growth for the combinations of AME and LME, AME and ampicillin, and LME and ampicillin at a 8-h incubation, while those against MRSA (2468 strain) were at 10-h incubation. The combination of α-mangostin and LME as well as the combinations of each compound with ampicillin synergized the alteration of membrane permeability. In addition, α-mangostin, LME and ampicillin inhibited the biofilm formation of MRSA. These findings indicated that the combinations of AME and LME or each of them in combination with ampicillin had enhanced antibacterial activity against MRSA. Therefore, these compounds might be used as the antibacterial cocktails for treatment of MRSA.     

Impacts of benzophenone-type UV filters on cladoceran Daphnia carinata

Limnology - The impacts of three commonly used benzophenone-type UV filters including benzophenone (BP), 2-hydroxy-4-methoxy-benzophenone (BP3), and 2-hydroxy-4-methoxy-benzophenone-5-sulfonicacid...     

Primate stem cells: bridge the translation from basic research to clinic application

A growing body of literature has shown that stem cells are very effective for the treatment of degenerative diseases in rodents but these exciting results have not translated to clinical practice. The difference results from the divergence in genetic, metabolic, and physiological phenotypes between rodents and humans. The high degree of similarity between non-human primates(NHPs) and humans provides the most accurate models for preclinical studies of stem cell therapy. Using a NHP model to understand the following key issues, which cannot be addressed in humans or rodents, will be helpful for extending stem cell applications in the basic science and the clinic. These issues include pluripotency of primate stem cells, the safety and efficiency of stem cell therapy, and transplantation procedures of stem cells suitable for clinical translation. Here we review studies of the above issues in NHPs and current challenges of stem cell applications in both basic science and clinical therapies. We propose that the use of NHP models, in particular combining the serial production and transplantation procedures of stem cells is the most useful for preclinical studies designed to overcome these challenges.     

A New Electrolyte Formulation for Securing High Temperature Cycling and Storage Performances of Na‐Ion Batteries

The Na‐ion battery is recognized as a possible alternative to the Li‐ion battery for applications where power and cost override energy density performance. However, the increasing instability of their electrolyte with temperature is still problematic. Thus, a central question remains how to design Na‐based electrolytes. Here, the discovery of a Na‐based electrolyte formulation is reported which enlists four additives (vinylene carbonate, succinonitrile, 1,3‐propane sultone, and sodium difluoro(oxalate)borate) in proper quantities that synergistically combine their positive attributes to enable a stable solid electrolyte interphase at both negative and positive electrodes surface at 55 °C. Moreover, the role of each additive that consists in producing specific NaF coatings, thin elastomers, sulfate‐based deposits, and so on via combined impedance and X‐ray photoelectron spectroscopy is rationalized. It is demonstrated that empirical electrolyte design rules previously established for Li‐ion technology together with theoretical guidance is vital in the quest for better Na‐based electrolytes that can be extended to other chemistries. Overall, this finding, which is implemented to 18 650 cells, widens the route to the rapid development of the Na‐ion technology based on Na₃V₂(PO₄)₂F₃/C chemistry.     

Zwitterions for Organic/Perovskite Solar Cells,Light‐Emitting Devices,and Lithium Ion Batteries: Recent Progress and Perspectives

Zwitterions, a class of materials that contain covalently bonded cations and anions, have been extensively studied in the past decades owing to their special features, such as excellent solubility in polar solvents, for solution processing and dipole formation for the transfer of carriers and ions. Recently, zwitterions have been developed as electrode modifiers for organic solar cells (OSCs), perovskite solar cells (PVSCs), and organic light‐emitting devices (OLEDs), as well as electrolyte additives for lithium ion batteries (LIBs). With the rapid advances of zwitterionic materials, high‐performance devices have been constructed with enhanced efficiencies by introducing them as interface layers and electrolyte additives. In this review, recent progress in OSCs, PVSCs, OLEDs, and LIBs by using zwitterions is highlighted. The authors also elaborate the role of various zwitterionic materials as interfacial layers and additives for highly efficient OSCs, PVSCs, OLEDs, and LIBs. This article presents an overview of device performance of zwitterionic materials. The structure–property relationship is also discussed. Finally, the prospects of zwitterion materials are also addressed.