Two pivotal RNA editing sites in the mitochondrial atp1mRNA are required for ATP synthase to produce sufficient ATP for cotton fiber cell elongation

RNA editing is a post-transcriptional maturation process affecting organelle transcripts in land plants. However, the molecular functions and physiological roles of RNA editing are still poorly understood. Using high-throughput sequencing, we identified 692 RNA editing sites in the Gossypium hirsutum mitochondrial genome. A total of 422 editing sites were found in the coding regions and all the edits are cytidine (C) to uridine (U) conversions. Comparative analysis showed that two editing sites in Ghatp1, C1292 and C1415, had a prominent difference in editing efficiency between fiber and ovule. Biochemical and genetic analyses revealed that the two vital editing sites were important for the interaction between the α and β subunits of ATP synthase, which resulted in ATP accumulation and promoted cell growth in yeast. Ectopic expression of C1292, C1415, or doubly edited Ghatp1 in Arabidopsis caused a significant increase in the number of trichomes in leaves and root length. Our results indicate that editing at C1292 and C1415 sites in Ghatp1 is crucial for ATP synthase to produce sufficient ATP for cotton fiber cell elongation. This work extends our understanding of RNA editing in atp1 and ATP synthesis, and provides insights into the function of mitochondrial edited Atp1 protein in higher plants.

Abstract 209: Education Level and Long-Term Outcomes After Acute Myocardial Infarction: The China PEACE Prospective AMI Study

Background: China has a growing burden of acute myocardial infarction (AMI) and wide variation in educational attainment. Less education is associated with worse cardiovascular outcomes in Western populations; whether this relationship exists in China is unclear. We assessed the association between educational attainment and AMI outcomes in China to inform future healthcare interventions.

Methods: We used data from the prospective China PEACE-Prospective AMI study of 3369 consecutive patients hospitalized with AMI from 53 hospitals across all 21 provinces between 2012 and 2015. We collected detailed information from abstraction of hospital records, supplemented with patient interviews. Educational attainment was categorized into: high (high school, college or postgraduate degree), intermediate (junior high school), or low (primary school or illiterate). We used survival models to assess the relationship between education and 1-year all-cause mortality and major adverse cardiovascular events (MACE: all-cause death, nonfatal myocardial infarction, nonfatal stroke, heart failure), both unadjusted and after adjustment for demographic characteristics and cardiovascular risk factors.

Results: The mean participant age was 60.7±11.9 years, 23.2% (781 of 3369) were women, and 33.3% (1123 of 3369) had high, 32.4% (1092 of 3369) intermediate, and 34.3% (1154 of 3369) low educational attainment. In unadjusted analysis, compared with high educational attainment, low educational attainment was associated with a higher 1-year risk of death (HR for low vs high education 3.09, 95% CI 1.69-5.65) and MACE (HR 2.41, 95% CI 1.72-3.37)(Figure). In risk-adjusted analyses, the association between education and mortality was attenuated and no longer statistically significant (adjusted HR 1.68, 95%CI 0.89-3.19, P = .11). However, the risk of MACE at one year remained significantly greater (adjusted HR 1.81, 95%CI 1.27-2.58, P = .001).

Conclusions: In a national Chinese cohort of patients hospitalized with AMI, lower educational attainment was associated with a higher risk of adverse events in the year following discharge. This association highlights the need to explore mechanisms underlying this relationship, and to consider interventions for adults with lower levels of education.

Pathway and mechanism of nitrogen transformation during composting: Functional enzymes and genes under different concentrations of PVP-AgNPs

Polyvinylpyrrolidone coated silver nanoparticles (PVP-AgNPs) were applied at different concentrations to reduce total nitrogen (TN) losses and the mechanisms of nitrogen bio-transformation were investigated in terms of the nitrogen functional enzymes and genes. Results showed that mineral N in pile 3 which was treated with AgNPs at a concentration of 10 mg/kg compost was the highest (6.58 g/kg dry weight (DW) compost) and the TN loss (47.07%) was the lowest at the end of composting. Correlation analysis indicated that TN loss was significantly correlated with amoA abundance. High throughput sequencing showed that the dominant family of ammonia-oxidizing bacteria (AOB) was Nitrosomonadaceae, and the number of Operational Taxonomic Units (OTUs) reduced after the beginning of composting when compared with day 1. In summary, treatment with AgNPs at a concentration of 10 mg/kg compost was considerable to reduce TN losses and reserve more mineral N during composting.

Transcriptomic profiling of tall fescue in response to heat stress and improved thermotolerance by melatonin and 24-epibrassinolide

Background

Tall fescue is a widely used cool season turfgrass and relatively sensitive to high temperature. Chemical compounds like melatonin (MT) and 24-epibrassinolide (EBL) have been reported to improve plant heat stress tolerance effectively.

Results

In this study, we reported that MT and EBL pretreated tall fescue seedlings showed decreased reactive oxygen species (ROS), electrolyte leakage (EL) and malondialdehide (MDA), but increased chlorophyll (Chl), total protein and antioxidant enzyme activities under heat stress condition, resulting in improved plant growth. Transcriptomic profiling analysis showed that 4311 and 8395 unigenes were significantly changed after 2 h and 12 h of heat treatments, respectively. Among them, genes involved in heat stress responses, DNA, RNA and protein degradation, redox, energy metabolisms, and hormone metabolism pathways were highly induced after heat stress. Genes including FaHSFA3, FaAWPM and FaCYTC2 were significantly upregulated by both MT and EBL treatments, indicating that these genes might function as the putative target genes of MT and EBL.

Conclusions

These findings indicated that heat stress caused extensively transcriptomic reprogramming of tall fescue and exogenous application of MT and EBL effectively improved thermotolerance in tall fescue.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4588-y) contains supplementary material, which is available to authorized users.

Chaperonin-containing T‑complex protein 1 subunit 8 promotes cell migration and invasion in human esophageal squamous cell carcinoma by regulating α-actin and β-tubulin expression

The chaperonin-containing T‑complex protein 1 (CCT) has eight subunits, CCT 1-8, which are dysregulated in several types of cancer. To determine how subunit 8 (CCT8) influences the development of esophageal squamous cell carcinoma (ESCC), immunohistochemistry and western blot analysis were performed on 128 ESCC samples in the present study to measure the expression of CCT8. The prognostic value of CCT8 was analyzed using univariate and multivariate survival analyses. CCT8 knockdown in ESCC cells was performed and subsequently, the migration and invasion of ESCC cells was assessed. The results of immunohistochemistry and western blot analysis of ESCC tissue indicated that the expression of CCT8 in tumor tissues from patients with lymph node metastasis (LNM) was high whereas its expression in tissues from those without LNM was low. In addition, the overall survival rate of patients with high CCT8 expression was poor. It was demonstrated that CCT8 influenced the migration and invasion of ESCC cells by regulating α-actin and β-tubulin. Following CCT8 knockdown, cells were treated with cisplatin; it was demonstrated that α-actin and β-tubulin were downregulated and that cell apoptosis was enhanced. These data confirm that α-actin and β-tubulin are regulated by CCT8, and that increased CCT8 expression is associated with poor patient prognosis and cisplatin resistance in ESCC.

[A cross-sequence labeling equipment for high-throughput proteome based on pseudo-isobaric dimethyl labeling]

Facing the needs of multidimensional and multi-sample proteome quantification in the field of biology and precision medicine, high-throughput quantitative labeling and analysis have become the trend in recent years. A novel cross-sequence labeling equipment for high-throughput proteome based on pseudo-isobaric dimethyl labeling (pIDL-StageTip) was established. The equipment needs only simple devices and centrifugal force. The throughput of quantitative labeling is effectively increased, and the controllability of the two-step labeling reaction time at the terminals of the peptides and the ease of operation are ensured. By optimizing the labeling conditions of NaBD₃CN and NaBH₃CN under acidic conditions respectively, labeling efficiency of the standard proteolysis achieved 100% and labeling selectivity was more than 95%. Even in the complex human proteome, the labeling efficiency was greater than 99% and the labeling selectivity was 100%. The quantitative method based on the equipment showed high quantitative accuracy and precision. The equipment provides a reliable solution for quantitative proteome labeling with high operability, accuracy, and throughput.

Adenoviruses-mediated RNA interference targeting cytosolic phospholipase A2α attenuates focal ischemic brain damage in mice

Cerebral ischemia injury is a clinical, frequently occurring disease, which causes a heavy burden on society and families. It has been demonstrated that cytosolic phospholipase A2α (cPLA2α) is significant in neurological injury caused by ischemic brain injury, and inhibition of cPLA2α may reduce stroke injury. In the present study, the role of cPLA2α was investigated in a mouse model of middle cerebral artery occlusion and/or reperfusion (MCAO/R) using an effective cPLA2α inhibitor and adenoviruses-mediated RNA interference. The most effective recombinant adenovirus encoding cPLA2α small interfering RNA (pAd-siRNA-cPLA2α) was constructed and selected. MCAO/R surgery is used to construct the model of focal ischemic brain damage in mice. Adenoviruses-mediated RNA interference targeting cPLA2α was administered by stereotactic surgery 2 h before the MCAO/R. The expression/activity of cPLA2α and cPLA2α-derived injurious lipid mediators was assessed. pAd-siRNA-cPLA2α-treated animals (RNA interference; RNAi group) were compared with pAd-siRNA-control-treated animals (negative group) with regard to neurological deficit, motor function, pathological changes, apoptosis, and infarct volume. The RNAi group animals reduced the expression level of cPLA2α, as determined by western blotting and reverse transcription-quantitative polymerase chain reaction, the improvement of locomotor function was evaluated by rotarod test, and the decrease of apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end-labeling staining. The decreased infarct areas were evaluated by 2,3,5-triphenyltetrazolium chloride staining. The expression levels of prostaglandin E2, leukotrienes B4, lysophosphatidylcholine and free fatty acids were reduced in the RNAi group when compared with the negative control group. Thus, the data indicates that the expression level of cPLA2α was effectively controlled by pAd-siRNA-cPLA2α treatment. pAd-siRNA-cPLA2α treatment, in reducing the levels of inflammatory factors, neurological deficit and tissue damage, represents an effective potential therapeutic strategy. pAd-siRNA-cPLA2α reduces cPLA2α expression levels with long-term efficacy, thereby improving functional deficits and effectively attenuating ischemic brain damage. Thus, pAd-siRNA-cPLA2α shows potential value for therapeutic evaluation in ischemic brain damage.

Intercellular communication of DNA damage and oxidative status underpin bystander effects

PURPOSE

A well-known phenomenon in the field of radiation biology is that cells exposed to ionizing radiation (IR) (targeted cells) can induce in non-irradiated (non-targeted), bystander cells effects reminiscent of DNA damage responses (DDR) normally expected, exclusively in targeted cells. These phenomena are collectively referred to as radiation-induced bystander effects (RIBE) and have different manifestations depending on the endpoint studied. Although it is now recognized that RIBE reflects to a considerable extent communication by the targeted cells to undamaged cells of their damaged status, the molecular underpinnings of this communication and its significance for the organism are only partly understood. In particular, it remains unknown why and how targeted cells induce DNA damage in non-targeted, bystander cells threatening their genomic stability and risking thus their transformation to cancer cells. Here, we outline observations hinting to possible sources of artifacts in experiments designed to detect RIBE and summarize a model according to which targeted cells modulate their redox status as part of their overall response to IR and use this modified redox status as a source to generate signals that are transmitted to non-irradiated cells of the organism.

MATERIAL AND METHODS

A synthesis of published evidence is presented.

RESULTS

Depending on type, RIBE signals may be transmitted through various forms of direct intercellular contact, through molecules acting locally in a paracrine fashion, or through molecules acting remotely in an endocrine fashion. We reason that DNA damage generated in bystander cells is unlikely to manifest the clustered character exhibited in directly exposed cells and postulate that RIBE will depend on complications generated when simpler forms of damage encounter the DNA replication fork.

CONCLUSIONS

We suggest that RIBE result from intercellular communication mechanisms designed to spread within tissues, or the organism, alarm signals of DNA damage inflicted in subsets of the constituent cells. This response likely evolved to protect organisms by appropriately modulating stress response, repair or apoptosis, and may in some instances also cause adverse effects, e.g. as collateral damage.

FGF 21 deficiency slows gastric emptying and reduces initial blood alcohol concentration in mice exposed to acute alcohol in fasting state

Excess alcohol consumption can lead to alcoholic liver disease. Fibroblast growth factor 21 (FGF21) is a metabolic regulator with multiple physiologic functions. Previous study demonstrated that FGF21 deficiency exacerbated alcohol-induced liver injury and exogenous FGF21 administration protected liver from chronic alcohol-induced injury. In this study, we aimed to explore the role of FGF21 in alcohol metabolism in mice. FGF21 knockout (KO) mice and the wild type(WT) control mice were divided into two groups and fasted for 24 h followed by a bonus of alcohol treatment at a dose of 5 g/kg body weight via gavage. Serum alcohol concentration was measured after gavage at 0.5, 2, 3, 4 and 6 h, respectively. At the end, gastric and liver tissues were collected. Serum alcohol concentration of KO mice was significantly lower than that of WT at 0.5 h after alcohol expose. There were no significant differences in alcohol dehydrogenase (ADH) activity and aldehyde dehydrogenase 2 (ALDH2) activity in gastric and liver tissues between WT and the KO mice. However, gastric emptying time of KO mice was much longer than that of WT mice. In addition, the intestinal permeability and serum GLP-1 level of KO mice were significantly higher than that of WT mice. These results suggest that FGF21 deficiency slow gastric emptying rate and indirectly influence initial alcohol metabolism in mice exposed to acute alcohol. Our findings provide additional information for understanding the gastrointestinal mechanism of alcoholic liver disease and other alcohol use disorders.

Quantitative analysis of core fucosylation of serum proteins in liver diseases by LC-MS-MRM

Aberrant core fucosylation of proteins has been linked to liver diseases. In this study, we carried out multiple reaction monitoring (MRM) quantification of core fucosylated N-glycopeptides of serum proteins partially deglycosylated by a combination of endoglycosidases (endoF1, endoF2, and endoF3). To minimize variability associated with the preparatory steps, the analysis was performed without enrichment of glycopeptides or fractionation of serum besides the nanoRP chromatography. Specifically, we quantified core fucosylation of 22 N-glycopeptides derived from 17 proteins together with protein abundance of these glycoproteins in a cohort of 45 participants (15 disease-free control, 15 fibrosis and 15 cirrhosis patients) using a multiplex nanoUPLC-MS-MRM workflow. We find increased core fucosylation of 5 glycopeptides at the stage of liver fibrosis (i.e., N630 of serotransferrin, N107 of alpha-1-antitrypsin, N253 of plasma protease C1 inhibitor, N397 of ceruloplasmin, and N86 of vitronectin), increase of additional 6 glycopeptides at the stage of cirrhosis (i.e., N138 and N762 of ceruloplasmin, N354 of clusterin, N187 of hemopexin, N71 of immunoglobulin J chain, and N127 of lumican), while the degree of core fucosylation of 10 glycopeptides did not change. Interestingly, although we observe an increase in the core fucosylation at N86 of vitronectin in liver fibrosis, core fucosylation decreases on the N169 glycopeptide of the same protein. Our results demonstrate that the changes in core fucosylation are protein and site specific during the progression of fibrotic liver disease and independent of the changes in the quantity of N-glycoproteins. It is expected that the fully optimized multiplex LC-MS-MRM assay of core fucosylated glycopeptides will be useful for the serologic assessment of the fibrosis of liver. BIOLOGICAL SIGNIFICANCE: We have quantified the difference in core fucosylation among three comparison groups (healthy control, fibrosis and cirrhosis patients) using a sensitive and selective LC-MS-MRM method. Despite an overall increase in core fucosylation of many of the glycoproteins that we examined, core fucosylation changed in a protein- and site-specific manner. Moreover, increased and decreased fucosylation was observed on different N-glycopeptides of the same protein. Altered core fucosylation of N-glycopeptides might be used as an alternative serologic assay for the evaluation of fibrotic liver disease.

Physicochemical transformation of Fe/Ni bimetallic nanoparticles during aging in simulated groundwater and the consequent effect on contaminant removal

To assess the fate and long-term reactivity of bimetallic nanoparticles used in groundwater remediation, it is important to trace the physicochemical transformation of nanoparticles during aging in water. This study investigated the short-term (within 5 d) and long-term (up to 90 d) aging process of Fe/Ni bimetallic nanoparticles (Fe/Ni BNPs) in simulated groundwater and the consequent effect on the particle reactivity. Results indicate that the morphological, compositional and structural transformation of Fe/Ni BNPs happened during the aging. In the 5-d short-term aging, Fe⁰ corrosion occurred rapidly and was transformed to ferrous ions which were adsorbed onto the surface of Fe/Ni BNPs, accompanied by the elevation of solution pH and the negative redox potential. In the long-term aging, scanning electron microscopy (SEM) images show that the particles transformed from spherical to rod-like and further to sheet-like and needle-like. X-ray diffraction (XRD) analysis reveals that the main aging product was magnetite (Fe₃O₄) and/or maghemite (γ-Fe₂O₃) after aging for 60-90 d. Energy dispersive spectrometer (EDS) analysis demonstrates that the mass ratio of Fe/Ni increased with aging, revealing that Ni were possibly gradually entrapped and covered by the iron oxides. Besides, the release of Ni into solution was also detected during the aging. The reactivity of the aged Fe/Ni BNPs was examined by studying its performance in tetracycline (TC) removal. The aged Fe/Ni BNPs within 2 d kept similar removal efficiency of TC as the fresh particles. However, the removal efficiency of TC by Fe/Ni BNPs aged for 5-15 d dropped by 20-50% due to aggregation and oxidation of particles, and the removal efficiency further decreased slowly with the prolongation of aging time up to 90 d. This reveals that Fe/Ni BNPs were vulnerable to passivation in water environments.

Total Mesorectal Excision for Rectal Cancer: Laparoscopic versus Open Approach

Aims and background

To evaluate the oncologic safety of laparoscopic total mesorectal excision for rectal cancer.

Methods and study design

Patients who underwent laparoscopic (n = 256) or open (n = 173) total mesorectal excision for rectal cancer between June 2005 and June 2011 were included. Long-term survival operative data and postoperative recovery were retrospectively reviewed from a prospectively collected database.

Results

No significant difference was found between the two groups in terms of age, sex, tumor stage and preoperative comorbidities. Twelve patients were converted to open procedures. Differences were found in blood loss (55 ± 14.1 vs 152 ± 29.2 ml P <0.05), infection of incision (3.1% vs 12.7%, P <0.05) and postoperative stay (8.1 ± 3.0 vs 12.4 ± 6.3 days, P <0.05). Both groups were comparable regarding lymph node clearance specimen length and distal margin. There was no significant difference in overall survival between the two groups by the life-table method. However, operative time in the laparoscopic group was longer than in the open group (168 ± 27.6 vs 141 ± 21.9 min, P <0.05).

Conclusions

Laparoscopic total mesorectal excision for rectal cancer offers oncologic results similar to those obtained with the open procedure with a favorable short-term outcome. Continued use of the procedure in these patients is supported.

Analysis of oxidation degree of graphite oxide and chemical structure of corresponding reduced graphite oxide by selecting different-sized original graphite

The thermal exfoliation and reduction of graphite oxide (GO) is the most commonly used strategy for large-scale preparation of graphene, and the oxidation degree of GO would influence the chemical structure of prepared graphene, thereby affecting its final physical and chemical properties. In addition to serving as the precursor for synthesizing graphene, GO also possesses great potential for various important applications owing to its abundant oxygen-containing groups and hybrid electronic structure. Therefore, systematically studying the influencing factors on the oxidation degree of GO and clarifying the effect of oxidation degree on the corresponding graphene is particularly important. Herein, we have studied the effect of the lateral size of the original graphite on the oxidation degree of GO in order to control the oxidation degree of GO. GOs with different degrees of oxidation were synthesized using a modified Hummers method. The results of X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and Raman spectroscopy revealed that decreased lateral size of the original graphite would lead to increased oxidation degree of GO. Furthermore, the interlayer spacing of the GO samples achieved 0.9–1.0 nm, which indicated that the modified Hummers method could make well oxidized graphite. The corresponding reduced graphite oxide (rGO) was also prepared by low-temperature exfoliation of GO at 140 °C under ambient atmosphere. It was found that a larger lateral size of GO resulted in rGO with fewer oxygen-containing functional groups, but a smaller lateral size of graphite possessed a higher exfoliation degree with a larger specific surface area. More importantly, the relationship between binding energy (E_B) of photoelectron of C atom in oxygen-containing groups and the number of oxygen-containing groups in GO and rGO samples was analyzed theoretically.

The thermal reduction of GO is the most commonly used strategy for preparation of rGO, and the oxidation degree of GO would influence the chemical structure of prepared rGO, thereby affecting its physical and chemical properties.

CRTC2 promotes non-small cell lung cancer A549 migration and invasion in vitro

BACKGROUND

CRTC2 is highly expressed in lung cancer and contributes to lung cancer pathogenesis; however, whether CRTC2 promotes lung cancer metastasis remains unknown. In the present study, we investigated the role of CRTC2 in lung cancer metastasis in vitro.

METHODS

CRTC2 stable knockdown of lung cancer cell A549 was generated with small hairpin RNA and confirmed by quantitative reverse transcription-PCR and Western blot. Wound healing and invasion transwell assays were performed to explore migration and invasion activity, and Western blot was conducted to detect the expression of related proteins.

RESULTS

Suppression of CRTC2 significantly inhibited A549 cell migration and invasion in vitro. Mechanistic studies showed that knockdown of CRTC2 greatly downregulated MMP2 and MMP9 expression. CRTC2 silencing remarkably suppressed epithelial-mesenchymal transition by modulating the expression of E-cadherin and vimentin. Furthermore, suppression of CRTC2 expression significantly reduced MAPK/c-Jun N-terminal kinase activity.

CONCLUSION

CRTC2 may promote A549 migration and invasion by modulation of c-Jun N-terminal kinase-mediated epithelial-mesenchymal transition and matrix metalloproteinase expression.

Management and Short-Term Follow-Up Study of Transient Ischaemic Attack Patients in a University Teaching Hospital

Objective

The aim of this study was to describe the management of patients admitted to a university teaching hospital in China who were diagnosed of having transient ischaemic attack (TIA) and to determine the outcome within a 7-day and 90-day period.

Methods

A retrospective, hospital-based study included consecutive patients having TIA from July 2009 to February 2013 was performed. Demographic data, risk factors, symptoms, clinical management, ABCD2 scores were analysed. The main outcome variable was the occurrence of TIA and ischaemic stroke during the 7 and 90 days follow up periods.

Results

A total of 157 patients were evaluated. After excluding 3 patients (1.9%) because they were lost to follow-up, 154 patients were included in the study. All patients underwent a cranial computed tomogram (CT) to exclude intracranial haemorrhage. If the cranial CT scan result was negative for bleeding or other diagnoses, further comprehensive tests would be initiated following a standardised clinical assessment protocol at the time of hospitalisation. Totally 148 (96%) patients received antiplatelet therapy and 6 (4%) patients received anticoagulation therapy. Eight (5.2%) patients received stenting therapy. Only 3 (1.9%) and 6 (3.8%) TIA patients developed subsequent TIA within 7 days and 90 days respectively. Twelve (7.8%) TIA patients developed ischaemic stroke within 7 days and 19 (12.3%) within 90 days. All the 6 patients who had recurrence of TIA within 90 days proceeded to develop ischaemic stroke. The ABCD2 scores of patients experienced subsequent TIA and ischaemic stroke (4.94±1.39, n=19) were significantly higher than those of patients without recurrence (3.91±1.37, n=135; p<0.05). None of the patients who received stenting therapy developed subsequent TIA or ischaemic stroke during the follow up period.

Conclusions

Our findings suggest that in-patient evaluation and management of TIA may be a safe and effective strategy. Rapid diagnosis and implementation of treatments for TIA patients are crucial to reduce stroke risk. (Hong Kong j.emerg.med. 2014;21:92-97)

Bacterial community of a spider, Marpiss magister (Salticidae)

Arthropods are associated with various microorganisms which confer benefits to their hosts. Recently, research has been conducted on bacterial communities of insects to provide an insight into the potential interactions of the symbiotic bacteria and their hosts. Spiders are interesting to study as they are perceived to be natural enemies of pests. The effect of endosymbionts on spiders has been reported, but little is known about the overall bacterial communities present in spiders. Here, we report on the characterization of bacterial communities present in the whole body of the spider Marpiss magister using Illumina sequencing of 16S rRNA amplicons. Our study shows that the most abundant phyla of bacteria included Proteobacteria, Tenericutes, Bacteroidetes and Actinobacteria. At the genus level, the most abundant genera included Rickettsia, Wolbachia, Spiroplasma, and Cardinium. Besides these dominant endosymbionts, our study also showed the existence of bacteria in the genera Arthrobacter, Novosphingobium, Acinetobacter, Pseudomonas, Aquabacterium and Sphingomonas at an abundance ranging from 0.65 to 0.84%, and the existence of bacterial in genera Lactobacillus, Sphingobium, Methylobacterium, Bradyrhizobium, Propionibacterium, Brevundimonas, Achromobacter, Microbacterium, Corynebacterium, and Flavobacterium at a slightly lower abundance ranging from 0.1 to 0.5%. Therefore, our finding indicates that endosymbionts are not the only microbiota present in the spider M. magister, and other bacterial taxa also exist in its bacterial community.

Prevalence, associated risk factors, and phylogenetic analysis of Echinococcus granulosus isolated from freerange Tibetan pigs in Tibet, China

The current study was performed to investigate the prevalence, associated risk factors exploration and phylogenetic analysis of Echinococcus granulosus (E. granulosus) genotypes isolated from Tibetan pigs. A total 373 Tibetan pigs were examined during 2014 and 2015, and the variables potentially associated with E. granulosus infection were explored with a multivariable logistic regression model. E. granulosus cysts (n=37) were collected from Tibetan pigs (lungs or livers). Fragments amplification of mitochondrial (mt) DNA of cox1 (shorter and longer) and atp6 were employed. The genotype of E. granulosus were identified by sequence and phylogenetic analysis. Results showed the prevalence of E. granulosus in Tibetan pigs was 9.9%. The prevalence of E. granulosus in male and female Tibetan pigs was 6.8% and 13.3%, with a significant difference in the two genders (P<0.05). In different seasons, the infection rate of E. granulosus in Tibetan pigs were ranged from 5.8% to 12.3%. E. granulosus infection rates in different growing stages of Tibetan pigs were ranged from 4.4% to 15.9%, with a statistical difference in the three stages (P<0.01). The prevalence of E. granulosus in Tibetan pigs were 7.9% in 2014 and 13.0% in 2015. Genders and growing stages were demonstrated to be risk factors to influence the prevalence significantly through multivariable logistic regression model. All the three fragments were successfully amplified from each of the 37 cysts. E. granulosus genotypes of G4 and G6 were identified by comparing with reference sequences of E. genotypes available at NCBI database and phylogenetic analysis by using MEGA software.

Atomically Thin Femtojoule Memristive Device

The morphology and dimension of the conductive filament formed in a memristive device are strongly influenced by the thickness of its switching medium layer. Aggressive scaling of this active layer thickness is critical toward reducing the operating current, voltage, and energy consumption in filamentary-type memristors. Previously, the thickness of this filament layer has been limited to above a few nanometers due to processing constraints, making it challenging to further suppress the on-state current and the switching voltage. Here, the formation of conductive filaments in a material medium with sub-nanometer thickness formed through the oxidation of atomically thin two-dimensional boron nitride is studied. The resulting memristive device exhibits sub-nanometer filamentary switching with sub-pA operation current and femtojoule per bit energy consumption. Furthermore, by confining the filament to the atomic scale, current switching characteristics are observed that are distinct from that in thicker medium due to the profoundly different atomic kinetics. The filament morphology in such an aggressively scaled memristive device is also theoretically explored. These ultralow energy devices are promising for realizing femtojoule and sub-femtojoule electronic computation, which can be attractive for applications in a wide range of electronics systems that desire ultralow power operation.

Metabolic engineering of Escherichia coli to high efficient synthesis phenylacetic acid from phenylalanine

Phenylacetic acid (PAA) is a fine chemical with a high industrial demand for its widespread uses. Whereas, microorganic synthesis of PAA is impeded by the formation of by-product phenethyl alcohol due to quick, endogenous, and superfluous conversion of aldehydes to their corresponding alcohols, which resulted in less conversation of PAA from aldehydes. In this study, an Escherichia coli K-12 MG1655 strain with reduced aromatic aldehyde reduction (RARE) that does duty for a platform for aromatic aldehyde biosynthesis was used to prompt more PAA biosynthesis. We establish a microbial biosynthetic pathway for PAA production from the simple substrate phenylalanine in E. coli with heterologous coexpression of aminotransferase (ARO8), keto acid decarboxylase (KDC) and aldehyde dehydrogenase H (AldH) gene. It was found that PAA transformation yield was up to ~94% from phenylalanine in E. coli and there was no by-product phenethyl alcohol was detected. Our results reveal the high efficiency of the RARE strain for production of PAA and indicate the potential industrial applicability of this microbial platform for PAA biosynthesis.