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181.
Aim Ixodes scapularis is the most important vector of human tick‐borne pathogens in the United States, which include the agents of Lyme disease, human babesiosis and human anaplasmosis, among others. The density of host‐seeking I. scapularis nymphs is an important component of human risk for acquiring Borrelia burgdorferi, the aetiological agent of Lyme disease. In this study we used climate and field sampling data to generate a predictive map of the density of host‐seeking I. scapularis nymphs that can be used by the public, physicians and public health agencies to assist with the diagnosis and reporting of disease, and to better target disease prevention and control efforts. Location Eastern United States of America. Methods We sampled host‐seeking I. scapularis nymphs in 304 locations uniformly distributed east of the 100th meridian between 2004 and 2006. Between May and September, 1000 m2 were drag sampled three to six times per site. We developed a zero‐inflated negative binomial model to predict the density of host‐seeking I. scapularis nymphs based on altitude, interpolated weather station and remotely sensed data. Results Variables that had the strongest relationship with nymphal density were altitude, monthly mean vapour pressure deficit and spatial autocorrelation. Forest fragmentation and soil texture were not predictive. The best‐fit model identified two main foci – the north‐east and upper Midwest – and predicted the presence and absence of I. scapularis nymphs with 82% accuracy, with 89% sensitivity and 82% specificity. Areas of concordance and discordance with previous studies were discussed. Areas with high predicted but low observed densities of host‐seeking nymphs were identified as potential expansion fronts. Main conclusions This model is unique in its extensive and unbiased field sampling effort, allowing for an accurate delineation of the density of host‐seeking I. scapularis nymphs, an important component of human risk of infection for B. burgdorferi and other I. scapularis‐borne pathogens.  相似文献   
182.
Herein, a novel electrospun single‐ion conducting polymer electrolyte (SIPE) composed of nanoscale mixed poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) and lithium poly(4,4′‐diaminodiphenylsulfone, bis(4‐carbonyl benzene sulfonyl)imide) (LiPSI) is reported, which simultaneously overcomes the drawbacks of the polyolefin‐based separator (low porosity and poor electrolyte wettability and thermal dimensional stability) and the LiPF6 salt (poor thermal stability and moisture sensitivity). The electrospun nanofiber membrane (es‐PVPSI) has high porosity and appropriate mechanical strength. The fully aromatic polyamide backbone enables high thermal dimensional stability of es‐PVPSI membrane even at 300 °C, while the high polarity and high porosity ensures fast electrolyte wetting. Impregnation of the membrane with the ethylene carbonate (EC)/dimethyl carbonate (DMC) (v:v = 1:1) solvent mixture yields a SIPE offering wide electrochemical stability, good ionic conductivity, and high lithium‐ion transference number. Based on the above‐mentioned merits, Li/LiFePO4 cells using such a SIPE exhibit excellent rate capacity and outstanding electrochemical stability for 1000 cycles at least, indicating that such an electrolyte can replace the conventional liquid electrolyte–polyolefin combination in lithium ion batteries (LIBs). In addition, the long‐term stripping–plating cycling test coupled with scanning electron microscope (SEM) images of lithium foil clearly confirms that the es‐PVPSI membrane is capable of suppressing lithium dendrite growth, which is fundamental for its use in high‐energy Li metal batteries.  相似文献   
183.
Elevations of carbon dioxide, temperature and ultraviolet‐B (UBV) radiation in the growth environment may have a high impact on the accumulation of carbon in plants, and the different factors may work in opposite directions or induce additive effects. To detect the changes in the growth and phytochemistry of silver birch (Betula pendula) seedlings, six genotypes were exposed to combinations of ambient or elevated levels of CO2, temperature and UVB radiation in top‐closed chambers for 7 weeks. The genotypes were relatively similar in their responses, and no significant interactive effects of three‐level climate factors on the measured parameters were observed. Elevated UVB had no effect on growth, nor did it alter plant responses to CO2 and/or temperature in combined treatments. Growth in all plant parts increased under elevated CO2, and height and stem biomass increased under elevated temperature. Increased carbon distribution to biomass did not reduce its allocation to phytochemicals: condensed tannins, most flavonols and phenolic acids accumulated under elevated CO2 and elevated UVB, but this effect disappeared under elevated temperature. Leaf nitrogen content decreased under elevated CO2. We conclude that, as a result of high genetic variability in phytochemicals, B. pendula seedlings have potential to adapt to the tested environmental changes. The induction in protective flavonoids under UVB radiation together with the positive impact of elevated CO2 and temperature mitigates possible UVB stress effects, and thus atmospheric CO2 concentration and temperature are the climate change factors that will dictate the establishment and success of birch at higher altitudes in the future.  相似文献   
184.
The aphid Schlechtendalia chinensis is an economically important insect that can induce horned galls, which are valuable for the medicinal and chemical industries. Up to now, more than twenty aphid genomes have been reported. Most of the sequenced genomes are derived from free‐living aphids. Here, we generated a high‐quality genome assembly from a galling aphid. The final genome assembly is 271.52 Mb, representing one of the smallest sequenced genomes of aphids. The genome assembly is based on contig and scaffold N50 values of the genome sequence are 3.77 Mb and 20.41 Mb, respectively. Nine‐seven percent of the assembled sequences was anchored onto 13 chromosomes. Based on BUSCO analysis, the assembly involved 96.9% of conserved arthropod and 98.5% of the conserved Hemiptera single‐copy orthologous genes. A total of 14,089 protein‐coding genes were predicted. Phylogenetic analysis revealed that S. chinensis diverged from the common ancestor of Eriosoma lanigerum approximately 57 million years ago (MYA). In addition, 35 genes encoding salivary gland proteins showed differentially when S. chinensis forms a gall, suggesting they have potential roles in gall formation and plant defense suppression. Taken together, this high‐quality S. chinensis genome assembly and annotation provide a solid genetic foundation for future research to reveal the mechanism of gall formation and to explore the interaction between aphids and their host plants.  相似文献   
185.
Chen LS  Li P  Cheng L 《Planta》2008,228(5):745-756
The sun-exposed peel of 'Gala' apple with or without sunburn was compared in terms of photooxidation and photoprotection, and a controlled experiment was conducted to probe the initial responses of PSII to high light and high temperature. The content of carotenoids, lutein and xanthophylls on a chlorophyll basis was higher in the sunburned peel although they were lower expressed on a peel area basis. Significant loss of beta-carotene and neoxanthin was observed relative to chlorophylls in the sunburned peel. O(2) evolution rates and the activity of key enzymes in the Calvin cycle were lower in the sunburned peel, but the activity of these enzymes decreased to a lesser extent than the O(2) evolution rates. The activity of antioxidant enzymes in the ascorbate-glutathione cycle and the level of total ascorbate, total glutathione, and reduced glutathione were higher in the sunburned peel. However, the sunburned peel had higher H(2)O(2) and malondialdehyde contents. Fruit peels treated with high temperature (45 degrees C) alone showed a clear "K" step in their chlorophyll fluorescence transients whereas high temperature coupled with high light (1,600 mumol m(-2) s(-1)) led to the disappearance of the "K" step and a further decrease in F (V)/F (M) (similar to what was observed in the sunburned peel). We conclude that high temperature coupled with high light damages the PSII complexes at both the donor and acceptor sides. Although both the xanthophyll cycle and the antioxidant system are up-regulated in response to the photooxidative stress, this up-regulation does not provide enough protection against the photooxidation.  相似文献   
186.
[目的] 从罗源湾红树林浅滩土壤中筛选出产脲酶真菌,研究其对镧La(Ⅲ)的最大耐受浓度,利用其吸附和产脲酶作用诱导矿化回收稀土离子La(Ⅲ),以期为稀土离子La(Ⅲ)的资源回收提供菌种资源和应用技术指导。[方法] 从罗源湾红树林浅滩土壤中分离、筛选、纯化出可产脲酶及耐La(Ⅲ)真菌,通过ITS rDNA基因序列分析对其进行鉴定;同时,利用XRD、SEM-Mapping及FT-IR分析探讨菌株回收La(Ⅲ)的机理。[结果] 经分离、纯化得到一株可产脲酶及耐受高浓度La(Ⅲ)的真菌FZU-07,鉴定为尖孢镰刀菌(Fusarium oxysporum),其具有较强诱导矿化回收La(Ⅲ)的能力,对La(Ⅲ)的最大耐受浓度为400 mg/L。菌株FZU-07单独对La(Ⅲ)吸附回收效率为46.19%;在诱导矿化条件下回收效率可提高到99.16%。FT-IR和SEM-Mapping分析表明,尖孢镰刀菌吸附La(Ⅲ)与菌丝体表面的氨基、羟基、羰基和磷酸基团相关;XRD和SEM-Mapping结果表明诱导矿化是通过该菌的产脲酶特性,使尿素分解产生碳酸,并与钙离子结合生成球霰石晶型的碳酸钙,La(Ⅲ)被捕获在球霰石晶格中,形成La(Ⅲ)和碳酸钙的混合固相,以共沉淀的形式被回收。[结论] 菌株FZU-07,是一株具有产脲酶特性的尖孢镰刀菌(Fusarium oxysporum),且具有较强的诱导矿化回收La(Ⅲ)能力。表明微生物诱导碳酸钙沉淀是一种可行且生态友好的回收稀土离子的方法。  相似文献   
187.
Cadmium (Cd) is one of the most toxic elements and can be accumulated in plants easily; meanwhile, eIF5A is a highly conserved protein in all eukaryotic organisms. The present work tried to investigate whether eIF5A is involved in Cd accumulation and sensitivity in Arabidopsis (Arabidopsis thaliana L.) by comparing the wild‐type Columbia‐0 (Col‐0) with a knockdown mutant of AteIF5A‐2, fbr12‐3 under Cd stress conditions. The results showed that the mutant fbr12‐3 accumulated more Cd in roots and shoots and had significantly lower chlorophyll content, shorter root length, and smaller biomass, suggesting that downregulation of AteIF5A‐2 makes the mutant more Cd sensitive. Real‐time polymerase chain reaction revealed that the expressions of metal transporters involved in Cd uptake and translocation including IRT1, ZIP1, AtNramp3, and AtHMA4 were significantly increased but the expressions of PCS1 and PCS2 related to Cd detoxification were decreased notably in fbr12‐3 compared with Col‐0. As a result, an increase in MDA and H2O2 content but decrease in root trolox, glutathione and proline content under Cd stress was observed, indicating that a severer oxidative stress occurs in the mutant. All these results demonstrated for the first time that AteIF5A influences Cd sensitivity by affecting Cd uptake, accumulation, and detoxification in Arabidopsis.  相似文献   
188.
Major depressive disorder (MDD) is a socially detrimental psychiatric disorder, contributing to increased healthcare expenditures and suicide rates. However, no empirical laboratory-based tests are available to support the diagnosis of MDD. In this study, a NMR-based plasma metabonomic method for the diagnosis of MDD was tested. Proton nuclear magnetic resonance ((1)H NMR) spectra of plasma sampled from first-episode drug-na??ve depressed patients (n = 58) and healthy controls (n = 42) were recorded and analyzed by orthogonal partial least-squares discriminant analysis (OPLS-DA). The OPLS-DA score plots of the spectra demonstrated that the depressed patient group was significantly distinguishable from the healthy control group. Moreover, the method accurately diagnosed blinded samples (n = 26) in an independent replication cohort with a sensitivity and specificity of 92.8% and 83.3%, respectively. Taken together, NMR-based plasma metabonomics may offer an accurate empirical laboratory-based method applicable to the diagnosis of MDD.  相似文献   
189.
Present work reported the cloning and characterization of a human novel RNA binding gene Partner of NOB1 (PNO1), with a length of 1637bp and a putative open reading frame of 759 bp, isolated from human kidney. It is composed of seven exons and is localized on chromosome 2p14. Western blot showed that the molecular weight of PNO1 is about 35kDa. RT-PCR results in 16 human tissues indicated that PNO1 is expressed mainly in liver, lung, spleen and kidney, slightly in thymus, testis, ovary, respectively, but not in heart, brain, skeletal muscle, placenta, pancreas, prostate, small intestine, colon and peripheral blood leukocytes. GFP fusion expression in mammalian cells exhibited its localization in the nucleus, especially in nucleoli. Subcellular localization of thirteen GFP fusion PNO1 deletion proteins showed that the region of 92-230 aa is solely responsible for its nucleolar retention, and KH domain alone is not sufficient for nucleolar retention. The PNO1 family shows significant conservation in both eukaryotes and prokaryotes.  相似文献   
190.
Diao Y  Guo X  Li Y  Sun K  Lu L  Jiang L  Fu X  Zhu H  Sun H  Wang H  Wu Z 《Cell Stem Cell》2012,11(2):231-241
In mouse skeletal muscles, Pax7 uniquely marks muscle satellite cells and plays some important yet unknown functions at the perinatal stage. To elucidate its in vivo functions, we initiated a yeast two-hybrid screening to look for Pax7-interacting proteins and identified a previously uncharacterized Pax7- and Pax3-binding protein (Pax3/7BP). Pax3/7BP is a ubiquitously expressed nuclear protein, enriched in Pax7+ muscle precursor cells (MPCs), and serves as an indispensable adaptor for Pax7 to recruit the histone 3 lysine 4 (H3K4) methyltransferase (HMT) complex by bridging Pax7 and Wdr5. Knockdown of Pax3/7BP abolished the Pax3/7-associated H3K4 HMT activity and inhibited the proliferation of Pax7+ MPCs from young mice both in culture and in vivo. Id3 and Cdc20 were direct target genes of Pax7 and Pax3/7BP involved in the proliferation of Pax7+ MPCs. Collectively, our work establishes Pax3/7BP as an essential adaptor linking Pax3/7 with the H3K4 HMT to regulate the proliferation of MPCs.  相似文献   
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