Reduced glutamine synthetase activity alters the fecundity of female Bactrocera dorsalis (Hendel)

Glutamine synthetase (GS) is a key enzyme in glutamine synthesis and is associated with multiple physiological processes in insects, such as embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on female fecundity in the oriental fruit fly, Bactrocera dorsalis. Based on the cloning of BdGSs, mitochondrial BdGSm and cytoplasmic BdGSc, we determined their expressions in the tissues of adult B. dorsalis. BdGSm was highly expressed in the fat body, while BdGSc was highly expressed in the head and midgut. Gene silencing by RNA interference against two BdGSs isoforms suppressed target gene expression at the transcriptional level, leading to a reduced ovarian size and lower egg production. The specific inhibitor L-methionine S-sulfoximine suppressed enzyme activity, but only the gene expression of BdGSm was suppressed. A similar phenotype of delayed ovarian development occurred in the inhibitor bioassay. Significantly lower expression of vitellogenin and vitellogenin receptor was observed when GS enzyme activity was suppressed. These data illustrate the effects of two GS genes on adult fecundity by regulating vitellogenin synthesis in different ways

Construction of a Fish-like Robot Based on High Performance Graphene/PVDF Bimorph Actuation Materials.

Smart actuators have many potential applications in various areas, so the development of novel actuation materials, with facile fabricating methods and excellent performances, are still urgent needs. In this work, a novel electromechanical bimorph actuator constituted by a graphene layer and a PVDF layer, is fabricated through a simple yet versatile solution approach. The bimorph actuator can deflect toward the graphene side under electrical stimulus, due to the differences in coefficient of thermal expansion between the two layers and the converse piezoelectric effect and electrostrictive property of the PVDF layer. Under low voltage stimulus, the actuator (length: 20 mm, width: 3 mm) can generate large actuation motion with a maximum deflection of about 14.0 mm within 0.262 s and produce high actuation stress (more than 312.7 MPa/g). The bimorph actuator also can display reversible swing behavior with long cycle life under high frequencies. on this basis, a fish-like robot that can swim at the speed of 5.02 mm/s is designed and demonstrated. The designed graphene-PVDF bimorph actuator exhibits the overall novel performance compared with many other electromechanical avtuators, and may contribute to the practical actuation applications of graphene-based materials at a macro scale

Examining Scientific Writing Styles from the Perspective of Linguistic Complexity

Publishing articles in high-impact English journals is difficult for scholars around the world, especially for non-native English-speaking scholars (NNESs), most of whom struggle with proficiency in English. In order to uncover the differences in English scientific writing between native English-speaking scholars (NESs) and NNESs, we collected a large-scale data set containing more than 150,000 full-text articles published in PLoS between 2006 and 2015. We divided these articles into three groups according to the ethnic backgrounds of the first and corresponding authors, obtained by Ethnea, and examined the scientific writing styles in English from a two-fold perspective of linguistic complexity: (1) syntactic complexity, including measurements of sentence length and sentence complexity; and (2) lexical complexity, including measurements of lexical diversity, lexical density, and lexical sophistication. The observations suggest marginal differences between groups in syntactical and lexical complexity.Comment: 6 figure

Improvement of colchicine oral bioavailability by incorporating eugenol in the nanoemulsion as an oil excipient and enhancer

The effect of eugenol on colchicine transport across an isolated rat intestinal membrane was studied using an in vitro diffusion chamber system. We found that eugenol increased the absorptive transport of the drug efficiently. The effect of eugenol on intestinal absorption of colchicine in an oral administrative nanoemulsion formulation was also demonstrated in vivo. The colchicine nanoemulsion was prepared with isopropyl myristate, eugenol, Tween80, ethanol and water, and eugenol was used as an oil phase in the formulation; an average particle size of this nanoemulsion was 41.2 ± 7.2 nm. The permeation of colchicine in the nanoemulsion across the intestinal membrane was significantly different from that of the control group (0.2 mM colchicine). Finally, co-administration of eugenol in colchicine nanoemulsion to enhance the colchicine bioavailability was investigated by an oral administration method. After oral administration of colchicine (8 mg/kg) in the form of either the nanoemulsion or in free colchicine solution, the relative bioavailability of nanoemulsion and eugenol–nanoemulsion were enhanced by about 1.6- and 2.1-fold, respectively, compared with free colchicine solution. The procedure indicated that the intestinal absorption of colchicine was enhanced significantly by eugenol in the tested nanoemulsion. All the results suggested that eugenol is an efficient component in an oral administrative formulation for improving the intestinal absorption of colchicine

Types of Scientific Collaborators: A Perspective of Author Contribution Network

The purpose of this study is to investigate interaction between collaborators within individual studies by measuring how they made contributions to their studies. Author contribution network is constructed based on the author contribution statements of 140,000 full-text articles in PloS by viewing every collaborator as a node and a shared contribution as an edge. Three types of contributors are identified: general team-players, factotums, and mavericks. The preliminary result suggests that division of labor widely exists in scientific re-search and the latter two types of collaborators are common in small teams