367 research outputs found

    Expression and evolutionary divergence of the non-conventional olfactory receptor in four species of fig wasp associated with one species of fig

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    <p>Abstract</p> <p>Background</p> <p>The interactions of fig wasps and their host figs provide a model for investigating co-evolution. Fig wasps have specialized morphological characters and lifestyles thought to be adaptations to living in the fig's syconium. Although these aspects of natural history are well documented, the genetic mechanism(s) underlying these changes remain(s) unknown. Fig wasp olfaction is the key to host-specificity. The <it>Or83b</it> gene class, an unusual member of olfactory receptor family, plays a critical role in enabling the function of conventional olfactory receptors. Four <it>Or83b</it> orthologous genes from one pollinator (PFW) (<it>Ceratosolen solmsi</it>) and three non-pollinator fig wasps (NPFWs) (<it>Apocrypta bakeri, Philotrypesis pilosa </it>and <it>Philotrypesis </it>sp.) associated with one species of fig (<it>Ficus hispida</it>) can be used to better understand the molecular mechanism underlying the fig wasp's adaptation to its host. We made a comparison of spatial tissue-specific expression patterns and substitution rates of one orthologous gene in these fig wasps and sought evidence for selection pressures.</p> <p>Results</p> <p>A newly identified <it>Or83b </it>orthologous gene was named <it>Or2</it>. Expressions of <it>Or2 </it>were restricted to the heads of all wingless male fig wasps, which usually live in the dark cavity of a fig throughout their life cycle. However, expressions were widely detected in the antennae, legs and abdomens of all female fig wasps that fly from one fig to another for oviposition, and secondarily pollination. Weak expression was also observed in the thorax of PFWs. Compared with NPFWs, the <it>Or2 </it>gene in <it>C. solmsi </it>had an elevated rate of substitutions and lower codon usage. Analyses using Tajima's <it>D</it>, Fu and Li's <it>D* </it>and <it>F* </it>tests indicated a non-neutral pattern of nucleotide variation in all fig wasps. Unlike in NPFWs, this non-neutral pattern was also observed for synonymous sites of <it>Or2 </it>within PFWs.</p> <p>Conclusion</p> <p>The sex- and species-specific expression patterns of <it>Or2 </it>genes detected beyond the known primary olfactory tissues indicates the location of cryptic olfactory inputs. The specialized ecological niche of these wasps explains the unique habits and adaptive evolution of <it>Or2 </it>genes. The <it>Or2 </it>gene in <it>C. solmsi </it>is evolving very rapidly. Negative deviation from the neutral model of evolution reflects possible selection pressures acting on <it>Or2 </it>sequences of fig wasp, particularly on PFWs who are more host-specific to figs.</p

    The combination of 2d layered graphene oxide and 3d porous cellulose heterogeneous membranes for nanofluidic osmotic power generation

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    Salinity gradient energy, as a type of blue energy, is a promising sustainable energy source. Its energy conversion efficiency is significantly determined by the selective membranes. Recently, nanofluidic membrane made by two-dimensional (2D) nanomaterials (e.g., graphene) with densely packed nanochannels has been considered as a high-efficient membrane in the osmotic power generation research field. Herein, the graphene oxide-cellulose acetate (GO–CA) heterogeneous membrane was assembled by combining a porous CA membrane and a layered GO membrane; the combination of 2D nanochannels and 3D porous structures make it show high surface-charge-governed property and excellent ion transport stability, resulting in an efficient osmotic power harvesting. A power density of about 0.13 W/m2 is achieved for the sea–river mimicking system and up to 0.55 W/m2 at a 500-fold salinity gradient. With different functions, the CA and GO membranes served as ion storage layer and ion selection layer, respectively. The GO–CA heterogeneous membrane open a promising avenue for fabrication of porous and layered platform for wide potential applications, such as sustainable power generation, water purification, and seawater desalination

    Surface chemistry and structure manipulation of graphene-related materials to address the challenges of electrochemical energy storage

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    Energy storage devices are important components in portable electronics, electric vehicles, and the electrical distribution grid. Batteries and supercapacitors have achieved great success as the spearhead of electrochemical energy storage devices, but need to be further developed in order to meet the ever-increasing energy demands, especially attaining higher power and energy density, and longer cycling life. Rational design of electrode materials plays a critical role in developing energy storage systems with higher performance. Graphene, the well-known 2D allotrope of carbon, with a unique structure and excellent properties has been considered a “magic” material with its high energy storage capability, which can not only aid in addressing the issues of the state-of-the-art lithium-ion batteries and supercapacitors, but also be crucial in the so-called post Li-ion battery era covering different technologies, e.g., sodium ion batteries, lithium-sulfur batteries, structural batteries, and hybrid supercapacitors. In this feature article, we provide a comprehensive overview of the strategies developed in our research to create graphene-based composite electrodes with better ionic conductivity, electron mobility, specific surface area, mechanical properties, and device performance than state-of-the-art electrodes. We summarize the strategies of structure manipulation and surface modification with specific focus on tackling the existing challenges in electrodes for batteries and supercapacitors by exploiting the unique properties of graphene-related materials

    Insolation driven biomagnetic response to the Holocene Warm Period in semi-arid East Asia

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    The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly favourable for magnetofossil proliferation in the semi-arid Asian interior. The pronounced increase of magnetofossil concentrations at ~9.8 ka and decrease at ~5.9 ka in Dali Lake coincided respectively with the onset and termination of the HWP, and are respectively linked to increased nutrient supply due to postglacial warming and poor nutrition due to drying at ~6 ka in the Asian interior. The two-stage transition at ~7.7 ka correlates well with increased organic carbon in middle HWP and suggests that improved climate conditions, leading to high quality nutrient influx, fostered magnetofossil proliferation. Our findings represent an excellent lake record in which magnetofossil abundance is, through nutrient availability, controlled by insolation driven climate changes.This research was supported by the NSFC grant 41330104 and the 973 program grant 2012CB821900. J.X. was supported by the 973 program grant 2010CB833400 and the NSFC grant 41130101. J.L. received support from the NSFC grant 41374004. C.D. acknowledges further support from the NSFC grant 40925012 and the CAS Bairen Program

    Fluorescence quenching-based immunological probe for ticagrelor monitoring

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    Introduction: Ticagrelor is extensively utilized for the treatment of acute coronary syndromes (ACS), but its platelet aggregation inhibitory effects can potentially result in tissue bleeding, posing a serious risk to patients’ lives.Methods: In this study, we developed highly sensitive full length anti-ticagrelor Quenchbodies (Q-bodies) for fast monitoring of ticagrelor both in solution and serum for the first time. Ticagrelor coupled with N- hydroxysuccinimide (Ticagrelor-NHS) ester was also designed and synthesized for interaction and biological activity detection.Results: Both ATTO-labeled MEDI2452 (2452A) Q-body and TAMRA-labeled IgG 152 (152T) Q-body demonstrated efficient detection of ticagrelor and its active metabolite (TAM). The 2452A Q-body exhibited a broader detection range, while the 152T Q-body displayed a lower limit of detection (LOD). Under physiological conditions (Ticagrelor:TAM, 3:1), the concentration of ticagrelor was further measured, yielding LOD values of 4.65 pg/mL and 2.75 pg/mL for the two Q-bodies, with half-maximal effect concentrations of 8.15 ng/mL and 3.0 ng/mL, respectively.Discussion: Compared with traditional liquid chromatography-mass spectrometry (LC-MS) methods, anti-ticagrelor Q-bodies have higher sensitivity and detection speed. It enabled the completion of analysis within 3 min, facilitating rapid preoperative detection of blood drug concentration in ACS to determine the feasibility of surgery and mitigate the risk of intraoperative and postoperative hemorrhage. The swift detection of ticagrelor holds promise for enhancing individualized drug administration, preventing adverse reactions, and providing preoperative guidance

    Analysis of occupational identity among family doctor teams and its influencing factors in Chengdu

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    BackgroundThe contracted family doctor services are the embodiment of the implementation of the new medical reform policy, and the transformation of the grass-roots health service mode. Studies have proved that the occupational stress in medical staff was at a high level. The enhancement of professional identity will contribute to strengthen team building,alleviate job burnout, and reduce turnover intention of family doctors. ObjectiveTo investigate the current situation of occupational identity among family doctor teams in Chengdu, to examine potential influencing factors of occupational identity, and to provide a reference for promoting career development and team building of family doctor teams. MethodsMulti-stage random cluster sampling was adopted to enroll study participants form 46 primary healthcare centers where family doctor contract services were implemented among 23 districts and counties in Chengdu between March 4 and 26, 2021. A total of 2 681 family doctors participated in this survey. A self-reported survey was conducted to collect participants' demographic and occupational data. The Effort-Reward Imbalance (ERI)questionnaire was implemented to assess occupational stress. The Professional Identity Scale was used to appraise occupational identity. ResultsA total of 2 327 valid questionnaires were collected, with a valid recovery rate of 86.80%, involving 1 715 females (73.7%) and 612 males (26.3%), with dominant age groups of 26−35 years (43.3%) and 36−45 years (30.4%), a high proportion of being married (82.8%), having college (36.0%) and undergraduate (47.3%) education, a high proportion of primary titles (66.0%) and informal work contract (66.1%). About 88.7% of family doctor team workers reported occupational stress. The average score of occupational identity was (3.68±0.62) points. There were significant differences in occupational identity scores among different professional title, work contract, working years in medical institutions, income, and effort/reward ratio (EER) groups (P < 0.05). ERR was negatively correlated with occupational identity (rs=−0.495, P<0.05). The multiple regression model showed that occupational identity score in the non-staffed participants was lower than the score in the staffed ones (OR=0.429, 95%CI: 0.299−0.825). The occupational identity score in the participants having associate senior title or above was higher than in without professional title (OR=1.424, 95%CI: 1.194−2.328). The longer the working years, the higher the occupational identity score among the participants. The score of the more than 20 working years group was 1.820 times that of the less than 5 working years group (95%CI: 1.342−2.543). The higher the income, the higher the occupational identity score. The score of the 9001−12000 yuan per month group was 1.977 times that of the 1000−3000 yuan per month group (95%CI: 0.811−9.696) , and the score of the more than 12000 yuan per month group was 2.283 times that of the 1000−3000 yuan per month group (95%CI: 1.199−10.267). ConclusionThe family doctor team workers generally report occupational stress, and their occupational identity is at a medium level in Chengdu. Relevant managers should implement intervention measures against the main influencing factors to reduce their work tension and improve their occupational identity
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