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To suppress excessive gate voltage swings during switching, a resistance is normally used to limit the charging rate of the gate capacitance (C G ). Modern solutions, such as segmented gate drivers, can be used to dynamically control the gate resistance R G to minimize ringing while maintaining the fast-switching speed of the transistor. The timing or dynamic pattern of the gate resistance is critical in the optimization of the device and circuit performance. Traditionally, this gate drive pattern is obtained via a trial-and-error or iterative procedure. This paper proposes a method to automatically determine the timing intervals by monitoring the gate signal (V GATE ) through slope sensing with analog filter and subsequent mixed-signal processing. The output timing indicator (T SEG ) is then fed back to the segmented gate driver IC to achieve automatic adjustments of the dynamic driving pattern. The proposed system is able to determine the optimum T SEG for dynamic gate driving. For the SiC power MOSFET used in our testing, segmented R G driving between 2.5 and 10 Ω does not hinder the switching speed, while keeping the undershoot of the SiC module to be within 1 V or 5% of the total applied gate voltage.

Intelligent power modules (IPMs) are critical components within electric vehicle (EV) power inverters that require effective liquid cooling. IPM manufacturers are constantly evolving their designs in lockstep with advancements in switching transistor technology to deliver more power with increased efficiency. In particular, the imminent arrival of new IPMs based on wide-bandgap semiconductors poses new thermal challenges due to smaller die areas and increased heat fluxes. The question arises whether the traditional liquid cooling strategies will be sufficient to cool the next generation of EV IPMs as semiconductor technology transitions from Si IGBTs, to SiC MOSFETs and GaN power HEMTs, with progressively decreasing die areas. In this paper, this question is explored through an analytical solution of the heat equation in a representative model of a typical EV IPM heat exchanger (HX). It is shown that there exists a practical thermal limit to traditional EV IPM HXs which must be addressed by IPM and automotive parts manufacturers together. Thermal benchmarking experiments, supported by numerical simulations, of two commercially available IPMs are performed, confirming no violations of the derived thermal limit.

Background Helicobacter pylori (H. pylori) infection has become an international public health problem, and antibiotic-based triple or quadruple therapy is currently the mainstay of treatment. However, the effectiveness of these therapies decreases due to resistance to multiple commonly used antibiotics. Sanguisorba officinalis L. (S. officinalis), a traditional Chinese medicine clinically used for hemostasis and treatment of diarrhea, has various pharmacological activities. In this study, in vitro antimicrobial activity was used for the preliminary evaluation of S. officinalis against H. pylori. And a pharmacology analysis approach was also utilized to elucidate its underlying mechanisms against H. pylori infection. Methods Micro-broth dilution method, agar dilution method, checkerboard assay, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used for the assessment of anti-bacterial activity. Active ingredients screening, GO analysis, KEGG analysis, construction of PPI network, molecular docking, and RT-qPCR were used to elucidate the underlying pharmacological mechanisms of S. officinalis against H. pylori infection. Results The minimum inhibitory concentration (MIC) values of S. officinalis against multiple H. pylori strains including clinically isolated multi-drug resistant (MDR) strains were ranging from 160 to 320 µg/ml. These results showed that S. officinalis had additive interaction with four commonly used antibiotics and could exert antibacterial effect by changing the morphology of bacteria without developing drug resistance. Through network pharmacology analysis, 8 active ingredients in S. officinalis were screened out for subsequent studies. Among 222 putative targets of S. officinalis, 49 targets were identified as potential targets for treatment of H. pylori infection. And these 49 targets were significantly enriched in GO processes such as protein kinase B signaling, protein kinase activity, protein kinase binding, and KEGG pathways such as Pathways in cancer, MicroRNAs in cancer, and TNF signaling pathway. Protein-protein interaction analysis yielded 5 core targets (AKT1, VEGFA, EGFR, SRC, CCND1), which were validated by molecular docking and RT-qPCR. Conclusions Overall, this study confirmed the in vitro inhibitory activity of S. officinalis against H. pylori and explored the possible pharmacological mechanisms, laying the foundation for further research and clinical application.

Gate overshoot voltage prevention when driving E-mode GaN-based HEMTs is essential for system reliability and EMI suppression. Active gate drivers have been demonstrated to suppress gate voltage overshoot while maintaining fast turn-on. However, they normally require complex driving patterns that are determined using trial and error approaches. In this paper, an active gate driver with an integrated pattern generator is proposed to simplify the control of the dynamic gate driving strength pattern. For best trade-off between overshoot and transition speed, the gate resistance (or gate driving strength) must remain low but with a large resistance switched in briefly during the turn-on transition period. Switch timing of the driving pattern varies with load conditions and the types of transistor. To simplify the programming of the driving pattern, the gate driving strength can be controlled by changing only one external bias resistor in the proposed design. This in turn sets the bias current of a delay chain to adjust the timing of the gate driving strength pattern. The proposed design aims to create a systematic approach to simplify the selection of the gate driving strength pattern.

Jing-Jin Weng,* Jia-Zhang Wei,* Min Li, Shao-Jie Zhang, Yun-Zhong Wei, Han-Wei Wang, Dan-Xue Qin, Jin-Long Lu, He Jiang, Shen-Hong Qu Department of Otolaryngology & Head and Neck, The People’s Hospital of Guangxi Zhuang Autonomous Region, Nanning 530021, People’s Republic of China*These authors contributed equally to this work.Correspondence: Shen-Hong QuDepartment of Otolaryngology & Head and Neck, The People’s Hospital of Guangxi Zhuang Autonomous Region, No. 6 Taoyuan Road, Nanning 530021, People’s Republic of ChinaTel +86-771-2186580Fax +86-771-2186317Email qshdoctor@163.comObjective: The efficacy of surgery as the primary treatment modality for nasopharyngeal carcinoma (NPC) is yet to be clarified. Therefore, we aimed to explore the short- and long-term efficacy of surgery for early-stage NPC.Methods: We retrospectively evaluated 341 patients diagnosed with early-stage NPC between September 2010 and December 2015. Among them, 58 patients underwent endoscopic nasopharyngectomy combined with chemoradiotherapy, whereas 283 patients underwent conventional chemoradiotherapy. The patients who underwent concurrent chemoradiotherapy or radiotherapy alone were matched to patients who underwent surgery in a 1:2 ratio using propensity score matching to analyze the clinical efficacy of each therapeutic modality. The primary endpoint was survival, and the secondary endpoints were tumor regression rate and reduction in Epstein–Barr virus (EBV)-DNA levels.Results: After matching, 156 patients were enrolled (58 patients in the surgery group; 98 patients in the non-surgery group). The baseline data of the matched patients had good inter-group comparability (All P> 0.05). The surgery group had significantly higher 5-year overall survival (98.30% vs. 91.70%), disease-free survival (98.30% vs. 81.40%), and recurrence-free survival (100.00% vs. 90.10%) rates than did the non-surgery group (All P< 0.05). In total, 0 and 14 patients in the surgery and non-surgery groups, respectively, had residual cancer at the end of treatment (P=0.001). All patients in the surgery group tested negative for EBV-DNA, whereas two patients in the non-surgery group tested positive. The incidence of hematologic toxicity during treatment was similar between the two groups (All P> 0.05). Still, the incidence of severe oral mucositis was lower in the surgery group than in the non-surgery group (37.9% vs. 54.08%, P=0.051).Conclusion: Surgery can improve the clearance rate of EB virus and reduce tumor residue. Surgery may be a safe and effective treatment for early NPC.Keywords: nasopharyngeal carcinoma, endoscopic surgery, radiotherapy, prognosis

International audience; Crassaminicella sp. strain SY095 is an anaerobic mesophilic marine bacterium that was recently isolated from a deep-sea hydrothermal vent on the Southwest Indian Ridge. Here, we present the complete genome sequence of strain SY095. The genome consists of a chromosome of 3,046,753 bp (G + C content of 30.81%) and a plasmid of 36,627 bp (G + C content of 31.29%), encodes 2966 protein, 135 tRNA genes, and 34 rRNA genes. Numerous genes are related to peptide transport, amino acid metabolism, motility, and sporulation. This agrees with the observation that strain SY095 is a spore-forming, motile, and chemoheterotrophic bacterium. Further, the genome harbors multiple prophages that carry all the genes necessary for viral particle synthesis. Some prophages carry additional genes that may be involved in the regulation of sporulation. This is the first reported genome of a bacterium from the genus Crassaminicella, providing insights into the microbial adaptation strategies to the deep-sea hydrothermal vent environment.

International audience; Marine environments are generally characterized by low bulk concentrations of nutrients that are susceptible to steady or intermittent motion driven by currents and local turbulence. Marine bacteria have therefore developed strategies, such as very fast-swimming and the exploitation of multiple directional sensing-response systems in order to efficiently migrate towards favorable places in nutrient gradients. The magnetotactic bacteria (MTB) even utilize Earth's magnetic field to facilitate downward swimming into the oxic-anoxic interface, which is the most favorable place for their persistence and proliferation, in chemically stratified sediments or water columns. To ensure the desired flagella-propelled motility, marine MTBs have evolved an exquisite flagellar apparatus, and an extremely high number (tens of thousands) of flagella can be found on a single entity, displaying a complex polar, axial, bounce, and photosensitive magnetotactic behavior. In this review, we describe gene clusters, the flagellar apparatus architecture, and the swimming behavior of marine unicellular and multicellular magnetotactic bacteria. The physiological significance and mechanisms that govern these motions are discussed.

Ethnopharmacological relevance Canarium album Raeusch. belongs to the Burseraceae family. Its ripe fruits, known as Qing Guo (QG) in Traditional Chinese Medicine (TCM), are used to treat sore throat, cough, and fish or crab poisoning. QG was reported to have antibacterial activity, and it exerted excellent anti-Helicobacter pylori (H. pylori) activity in our screening of abundant TCM. However, few studies have reported its anti-H. pylori activity and mechanism. Aim of study The commonly used eradication therapies for H. pylori infection are antibiotic-based therapies. With the increasing antibiotic resistance of H. pylori, interest in finding alternative therapies has been aroused. This study investigated the phytochemistry profile, in vitro anti-H. pylori activity and possible anti-bacterial mechanism of QG extracts. Materials and methods QG extracts were obtained by heat reflux extraction, ultrasonic extraction or liquid-liquid extraction with different solvents. The quantitative and qualitative phytochemical analyses were performed by colorimetric determination, high-performance liquid chromatography (HPLC), and UPLC-electrospray ionization mass spectrometry (ESI-MS). In vitro anti- H. pylori activity was assessed by broth micro-dilution method. Mechanism of action studies included morphological observation using electron microscopy, urease inhibition assay and determination of expression of virulence genes by RT-qPCR. Results All QG extracts especially ethyl acetate extract (QGEAE) were rich in phenolic components, with the minimum inhibitory concentrations (MICs) on H. pylori of 39–625 μg/ml and minimum bactericidal concentrations (MBCs) of 78–1250 μg/ml. Both aqueous extract (QGAE) and QGEAE could induce the morphological and structural changes of H. pylori, inhibit urease activity with IC50 of 1093 μg/ml and 332.90 μg/ml, respectively, and down-regulate the virulence genes, such as vacA and cagA. Conclusions QG may exhibit in vitro anti-H. pylori activity by inhibiting growth, destroying the bacterial structure and down-regulating the expression of virulence factors. Moreover, QG is the homology of food and TCM, which can be considered as a safe and convenient agent against H. pylori infection.

Background Colorectal cancer (CRC) is a widespread cancer with high morbidity and mortality. Chemoresistance and metastasis are the current challenges for CRC treatment. Sanguisorba officinalis Linn. (called DiYu in Chinese, DY) is a Traditional Chinese medicine (TCM), which its root is long used as medicinal part. In our previous study, the aqueous extract of DY could inhibit the Wnt/β-catenin pathway and showed great antitumor effect against CRC. The Wnt/β-catenin pathway is involved in CRC chemoresistance and metastasis. However, there is little study on the antitumor and antimetastatic effects of DY on resistant CRC cells. The aim of this study is to explore the effect of aqueous extract of DY on the growth and metastasis of 5-fluorouracil (5-FU) sensitive and resistant CRC, and to elucidate the underlying molecular mechanism. Methodology In this study, cell viability, cell colony formation and apoptosis analyses were performed to verify the in vitro antitumor effect of DY on 5-FU-sensitive and -resistant CRC cells. Next, transwell assays were used to test the inhibition activity of DY on CRC migration and invasion. Western Blotting assays were carried out to identify the molecular mechanism underlying the efficacy of DY extract. Xenograft CRC nude mice model and tumor metastasis model were used to confirm the in vivo antitumor and antimetastatic effects of DY. Results DY inhibited cell proliferation and apoptosis via the upregulation of Bax, cleaved-caspase3 and cleaved-PARP proteins and downregulation of Bcl-2 protein. DY also inhibited cell migration and invasion via the downregulation of N-cadherin, vimentin and snail proteins and upregulation of E-cadherin protein, demonstrating that DY suppressed cell metastasis by reversing epithelial-to-mesenchymal transition (EMT) procession. Moreover, the protein expression levels of β-catenin in whole cell, cytoplasm and nucleus were decreased after DY treatment. Taken together, DY suppressed CRC cell growth and metastasis via inhibition of the Wnt pathway. Additionally, DY also demonstrated effective antitumor and anti-metastasis activities in vivo. Conclusions In conclusion, DY suppressed the growth and metastasis of 5-FU-sensitive and -resistant CRC via inhibition of the Wnt pathway, which indicated that DY could be a potential drug to treat CRC patients and improve clinic outcome.

Magnetosome formation by Magnetospirillum gryphiswaldense MSR-1 is dependent on iron and oxygen levels. We used transcriptome to evaluate transcriptional profiles of magnetic and non-magnetic MSR-1 cells cultured under high-iron and low-iron conditions. A total of 80 differentially expressed genes (DEGs) were identified, including 53 upregulated and 27 downregulated under high-iron condition. These DEGs belonged to the functional categories of biological regulation, oxidation-reduction process, and ion binding and transport, and were involved in sulfur metabolism and cysteine/methionine metabolism. Comparison with our previous results from transcriptome data under oxygen-controlled conditions indicated that transcription of mam or mms was not regulated by oxygen or iron signals. 17 common DEGs in iron- and oxygen-transcriptomes were involved in energy production, iron transport, and iron metabolism. Some unknown-function DEGs participate in iron transport and metabolism, and some are potential biomarkers for identification of Magnetospirillum strains. IrrA and IrrB regulate iron transport in response to low-oxygen and high-iron signals, respectively. Six transcription factors were predicted to regulate DEGs. Fur and Crp particularly co-regulate DEGs in response to changes in iron or oxygen levels, in a proposed joint regulatory network of DEGs. Our findings provide new insights into biomineralization processes under high- vs. low-iron conditions in magnetotactic bacteria.

Magnetotactic multicellular prokaryotes (MMPs) consist of unique microorganisms formed by genetically identical Gram-negative bacterial that live as a single individual capable of producing magnetic nanoparticles called magnetosomes. Two distinct morphotypes of MMPs are known: spherical MMPs (sMMPs) and ellipsoidal MMPs (eMMPs). sMMPs have been extensively characterized, but less information exists for eMMPs. Here, we report the ultrastructure and organization as well as gene clusters responsible for magnetosome and flagella biosynthesis in the magnetite magnetosome producer eMMP Candidatus Magnetananas rongchenensis. Transmission electron microscopy and focused ion beam scanning electron microscopy (FIB-SEM) 3D reconstruction reveal that cells with a conspicuous core-periphery polarity were organized around a central space. Magnetosomes were organized in multiple chains aligned along the periphery of each cell. In the partially sequenced genome, magnetite-related mamAB gene and mad gene clusters were identified. Two cell morphologies were detected: irregular elliptical conical ` frustum-like' (IECF) cells and H-shaped cells. IECF cells merge to form H-shaped cells indicating a more complex structure and possibly a distinct evolutionary position of eMMPs when compared with sMMPs considering multicellularity.

Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared with other bacterial taxonomic groups remain to be illustrated. Here, we analysed the genome of the marine magneto-ovoid strain MO-1 and found that it is closely related to Magnetococcus marinus MC-1. Detailed analyses of the ribosomal proteins and whole proteomes of 390 genomes reveal that, among the Proteobacteria analysed, only MO-1 and MC-1 have coding sequences (CDSs) with a similarly high proportion of origins from Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria and Gammaproteobacteria. Interestingly, a comparative metabolic network analysis with anoxic network enzymes from sequenced MTB and non-MTB successfully allows the eventual prediction of an organism with a metabolic profile compatible for magnetosome production. Altogether, our genomic analysis reveals multiple origins of MO-1 and M. marinus MC-1 genomes and suggests a metabolism-restriction model for explaining whether a bacterium could become an MTB upon acquisition of magnetosome encoding genes.

Aloe vera has been widely used in cosmetics and as a health product. Although increasing research has indicated that chronic use of Aloe vera is closely associated with the development of colorectal cancer, the material basis and molecular mechanism of the pathogenesis have not been elucidated. The wnt/β-catenin signaling pathway plays an important role in the development of colorectal cancer. It should be useful to investigate whether Aloe vera has any impact on the wnt/β-catenin signaling pathway. In this study, we found that a water extract of Aloe vera at low concentration (0.98–12.50 μg ml−1) could activate the wnt/β-catenin signaling pathway in the presence of wnt3a ligand and up-regulated the level of active β-catenin protein in hek293 cells, as well as promoting the expression of wnt target genes (Axin2, DKK1, FGF20). Additionally, aloin and aloesin were the effective components interacting with other non-active ingredients in the water extract of Aloe vera that were identified by a knockout/knockin method with high-speed counter current chromatography (HSCCC). Meanwhile, no effects of the water extract of Aloe vera and aloin on the wnt/β-catenin signaling pathway were found, either in the presence or absence of other activators such as activator CHIR99021. In conclusion, the water extract of Aloe vera could activate the wnt/β-catenin signaling pathway in the presence of wnt3a and the effective components were aloin and aloesin. These findings might facilitate the understanding of the material basis and molecular mechanisms of Aloe vera in causing colorectal cancer.

The evolution of microbial magnetoreception (or magnetotaxis) is of great interest in the fields of microbiology, evolutionary biology, biophysics, geomicrobiology, and geochemistry. Current genomic data from magnetotactic bacteria (MTB), the only prokaryotes known to be capable of sensing the Earth’s geomagnetic field, suggests an ancient origin of magnetotaxis in the domain Bacteria. Vertical inheritance, followed by multiple independent magnetosome gene cluster loss, is considered to be one of the major forces that drove the evolution of magnetotaxis at or above the class or phylum level, although the evolutionary trajectories at lower taxonomic ranks (e.g., within the class level) remain largely unstudied. Here we report the isolation, cultivation, and sequencing of a novel magnetotactic spirillum belonging to the genus Terasakiella (Terasakiella sp. strain SH-1) within the class Alphaproteobacteria. The complete genome sequence of Terasakiella sp. strain SH-1 revealed an unexpected duplication event of magnetosome genes within the mamAB operon, a group of genes essential for magnetosome biomineralization and magnetotaxis. Intriguingly, further comparative genomic analysis suggests that the duplication of mamAB genes is a common feature in the genomes of alphaproteobacterial MTB. Taken together, with the additional finding that gene duplication appears to have also occurred in some magnetotactic members of the Deltaproteobacteria, our results indicate that gene duplication plays an important role in the evolution of magnetotaxis in the Alphaproteobacteria and perhaps the domain Bacteria. IMPORTANCE A diversity of organisms can sense the geomagnetic field for the purpose of navigation. Magnetotactic bacteria are the most primitive magnetism-sensing organisms known thus far and represent an excellent model system for the study of the origin, evolution, and mechanism of microbial magnetoreception (or magnetotaxis). The present study is the first report focused on magnetosome gene cluster duplication in the Alphaproteobacteria, which suggests the important role of gene duplication in the evolution of magnetotaxis in the Alphaproteobacteria and perhaps the domain Bacteria. A novel scenario for the evolution of magnetotaxis in the Alphaproteobacteria is proposed and may provide new insights into evolution of magnetoreception of higher species.

GaN power transistors are well suited in high frequency, high temperature and high power-density applications. This paper investigates different gate driver designs for GaN power transistors, including fundamental driving concerns, current commercial products, popular gate driving features, and design trends for the suppression of gate node ringing. Many smart gate drivers offer features such as intelligent on-chip CPU for flexible digital control, adjustable gate voltage levels, multi-stage driving speed for slew-rate control, precise timing control, current sensing capability for close-loop regulations, and active gate driving mode with continuous optimized dead-time. This paper provides an overview to modern gate driver design trends and challenges for GaN power transistors.

In an effort to understand the molecular events contributing to the cytotoxicity activity of resveratrol (RSV), we investigated its effects on human lung adenocarcinoma epithelial cell line A549 at different concentrations. Cellular nucleoside metabolic profiling was determined by an established liquid chromatography-mass spectrometry method in A549 cells. RSV resulted in significant decreases and imbalances of deoxyribonucleoside triphosphates (dNTPs) pools suppressing subsequent DNA synthesis. Meanwhile, RSV at high concentration caused significant cell cycle arrest at S phase, in which cells required the highest dNTPs supply than other phases for DNA replication. The inhibition of DNA synthesis thus blocked subsequent progression through S phase in A549 cells, which may partly contribute to the cytotoxicity effect of RSV. However, hydroxyurea (HU), an inhibitor of RNR activity, caused similar dNTPs perturbation but no S phase arrest, finally no cytotoxicity effect. Therefore, we believed that the dual effect of high concentration RSV, including S phase arrest and DNA synthesis inhibition, was required for its cytotoxicity effect on A549 cells. In summary, our results provided important clues to the molecular basis for the anticancer effect of RSV on epithelial cells.

Detection of reverse-conduction in GaN-based switched-mode power converters is essential to reduce power loss and to protect the circuit from severe undershoot voltage. In this paper, an active clamping SenseFET circuit is proposed to measure the duration that the low-side GaN HEMT is in reverse-conduction and with protection from the high voltage at the switching node. The output of the SenseFET clamping circuit is processed by a custom designed gate driver IC. This IC is fabricated using TSMC's $0.18\ \boldsymbol{\mu} \mathbf{m}$ BCD GEN2 process for driving e-mode GaN power HEMTs with an on-chip closed-loop dead-time correction circuit. The one-step correction mode can optimize the dead-times for both the turn-on and turn-off edges in one switching cycle for switching frequencies of up to 10 MHz with 0.32 ns precision. This allow the power converters to maintain optimal conversion efficiency over the full output current range.

Shewanella benthica DB21MT-2 is an obligate piezophilic bacterium isolated from the sediment of the Mariana Trench at depth of 10,898 m. Here we report the complete genome sequence of S. benthica DB21MT-2, which consists of a single circular chromosome with the size of 4,353,505 bp and G + C content of 45.86%. Comparative genomic analysis reveals the strain possesses multiple pathways for energy generation as has been reported in other deep-sea bacteria. In addition, several genes predicted to be involved in flagellar synthesis or component of toxin-antitoxin system are specifically found in obligate piezophilic strains from hadal trench. The result is expected to provide novel information for a better understanding on bacterial obligate piezophilic life-style and on bacterial adaptation to hadal trench environment.

Tuberculosis (TB) is a continuing major threat to global health and a leading cause of death, particularly in developing countries. In this study, we aimed to identify a specific and sensitive diagnostic biomarker and develop a vaccine to prevent this disease. We investigated membrane proteins to reveal biomarkers in serum and peripheral blood mononuclear cells (PBMCs) obtained from TB patients. We employed Western blotting to evaluate serological immunoglobulin G levels, and Enzyme Linked Immunospot (ELISpot) to assess the antigen-specific cellular interferon-γ secretion from PBMCs after membrane protein stimulation. A total of 219 membrane proteins were identified, 52 exhibited at a higher levels than the 38-kDa prositive control. Of these 18 exhibited reacted ratios above 1, especially Rv1111c (427–981), with a ratios at 3.38. Accuracy and sensitivity were markedly higher for the top two antigen candidates, Rv0232 and Rv1115, after two rounds of ELISpot tests than ESAT-6 in the commercial kit (42.15 and 43.62%, respectively). These two proteins were administered to mice to detect whether they acted as effective antigens in vivo. These data provide a comprehensive view of the membranes involved in humoural and cellular immune responses that may be used as biomarkers for TB and candidates for a vaccine.

Many compounds of ginsenosides show anti-inflammatory properties. However, their anti-inflammatory effects in intervertebral chondrocytes in the presence of inflammatory factors have never been shown. Increased levels of pro-inflammatory cytokines are generally associated with the degradation and death of chondrocytes; therefore, finding an effective and nontoxic substance that attenuates the inflammation is worthwhile. In this study, chondrocytes were isolated from the nucleus pulposus tissues, and the cells were treated with ginsenoside compounds and IL-1β, alone and in combination. Cell viability and death rate were assessed by CCK-8 and flow cytometry methods, respectively. PCR, western blot, and immunoprecipitation assays were performed to determine the mRNA and protein expression, and the interactions between proteins, respectively. Monomeric component of ginsenoside Rd had no toxicity at the tested range of concentrations. Furthermore, Rd suppressed the inflammatory response of chondrocytes to interleukin (IL)-1β by suppressing the increase in IL-1β, tumor necrosis factor (TNF)-α, IL-6, COX-2, and inducible nitric oxide synthase (iNOS) expression, and retarding IL-1β-induced degradation of chondrocytes by improving cell proliferation characteristics and expression of aggrecan and COL2A1. These protective effects of Rd were associated with ubiquitination of IL-1 receptor accessory protein (IL1RAP), blocking the stimulation of IL-1β to NF-κB. Bioinformatics analysis showed that NEDD4, CBL, CBLB, CBLC, and ITCH most likely target IL1RAP. Rd increased intracellular ITCH level and the amount of ITCH attaching to IL1RAP. Thus, IL1RAP ubiquitination promoted by Rd is likely to occur by up-regulation of ITCH. In summary, Rd inhibited IL-1β-induced inflammation and degradation of intervertebral disc chondrocytes by increasing IL1RAP ubiquitination.

International audience; Trimethylamine N-oxide (TMAO) is widely dispersed in marine environments and plays an important role in the biogeochemical cycle of nitrogen. Diverse marine bacteria utilize TMAO as carbon and nitrogen sources or as electron acceptor in anaerobic respiration. Alteration of respiratory component according to the pressure is a common trait of deep-sea bacteria. Deep-sea bacteria from different genera harbor high hydrostatic pressure (HHP) inducible TMAO reductases that are assumed to be constitutively expressed in the deep-sea piezosphere and facilitating quick reaction to TMAO released from fish which is a potential nutrient for bacterial growth. However, whether deep-sea bacteria universally employ this strategy remains unknown. In this study, 237 bacterial strains affiliated to 23 genera of Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria were isolated from seawater, sediment or amphipods collected at different depths. The pressure tolerance and the utilization of TMAO were examined in 74 strains. The results demonstrated no apparent correlation between the depth where the bacteria inhabit and their pressure tolerance, regarding to our samples. Several deep-sea strains from the genera of Alteromonas, Halomonas, Marinobacter, Photobacterium, and Vibrio showed capacity of TMAO utilization, but none of the isolated Acinebacter, Bacillus, Brevundimonas, Muricauda, Novosphingobium, Rheinheimera, Sphingobium and Stenotrophomonas did, indicating the utilization of TMAO is a species-specific feature. Furthermore, we noticed that the ability of TMAO utilization varied among strains of the same species. TMAO has greater impact on the growth of deep-sea isolates of Vibrio neocaledonicus than shallow-water isolates. Taken together, the results describe for the first time the TMAO utilization in deep-sea bacterial strains, and expand our understanding of the physiological characteristic of marine bacteria.

Investigation into intracellular ribonucleotides (RNs) and deoxyribonucleotides (dRNs) is important for studies of the mechanism of many biological processes, such as RNA and DNA synthesis and DNA repair, as well as metabolic and therapeutic efficacy of nucleoside analogues. However, current methods are still unsatisfactory for determination of nucleotides in complex matrixes. Here we describe a novel method for the determination of RN and dRN pools in cells based on fast derivatization with (trimethylsilyl)diazomethane (TMSD) followed by quantification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Derivatization was accomplished in 3 min, and each derivatized nucleotide not only had a sufficient retention on reversed-phase column by introduction of methyl groups but also exhibited a unique ion transition which consequently eliminated mutual interference in LC-MS/MS. Chromatographic separation was performed on a C18 column with a simple acetonitrile-water gradient elution system, which avoided contamination and ion suppression caused by ion-pairing reagents. The developed method was fully validated and applied to the analysis of RNs and dRNs in cell samples. Moreover, results demonstrated that the applicability of this method could be extended to nucleoside analogues and their metabolites and could facilitate many applications in future studies.

Magnetosome synthesis ability of Magnetospirillum gryphiswaldense MSR-1 in an autofermentor can be precisely controlled through strict control of dissolved oxygen concentration. In this study, using transcriptome data we discovered gene transcriptional differences and compared physiological characteristics of MSR-1 cells cultured under aerobic (high-oxygen) and micro-aerobic (low-oxygen) conditions. The results showed that 77 genes were up-regulated and 95 genes were down-regulated significantly under micro-aerobic situation. These genes were involved primarily in the categories of cell metabolism, transport, regulation and unknown-function proteins. The nutrient transport and physiological metabolism were slowed down under micro-aerobic condition, whereas dissimilatory denitrification pathways were activated and it may supplemental energy was made available for magnetosome synthesis. The result suggested that the genes of magnetosome membrane proteins (Mam and Mms) are not directly regulated by oxygen level, or are constitutively expressed. A proposed regulatory network of differentially expressed genes reflects the complexity of physiological metabolism in MSR-1, and suggests that some yet-unknown functional proteins play important roles such as ferric iron uptake and transport during magnetosome synthesis. The transcriptome data provides a holistic view of the responses of MSR-1 cells to differing oxygen levels. This approach will give new insights into general principles of magnetosome formation.

International audience; Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced. Using optical mapping we updated the genomic data and reassembled it into two chromosomes and a large plasmid. Genomic analysis revealed a versatile energy metabolic potential and physiological analysis confirmed its growth capacity by deriving energy from fermentation of glucose or maltose, by respiration with formate as electron donor and trimethlyamine N-oxide (TMAO), nitrate or fumarate as electron acceptors, or by chemo-organo-heterotrophic growth in rich media. Despite that it was isolated at a site with saturated dissolved oxygen, the ANT-2200 strain possesses four gene clusters coding for typical anaerobic enzymes, the TMAO reductases. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The high copy number of the TMAO reductase isoenzymes and pressure-enhanced activity might imply a strategy developed by bacteria to adapt to deep-sea habitats where the instant TMAO availability may increase with depth.

SHANK2 is a scaffold protein that serves as a protein anchor at the postsynaptic density in neurons. Genetic variants of SHANK2 are strongly associated with synaptic dysfunction and the pathophysiology of autism spectrum disorder. Recent studies indicate that early neuronal developmental defects play a role in the pathogenesis of autism spectrum disorder, and that insulin-like growth factor 1 has a positive effect on neurite development. To investigate the effects of SHANK2 knockdown on early neuronal development, we generated a sparse culture system using human induced pluripotent stem cells, which then differentiated into neural progenitor cells after 3–14 days in culture, and which were dissociated into single neurons. Neurons in the experimental group were infected with shSHANK2 lentivirus carrying a red fluorescent protein reporter (shSHANK2 group). Control neurons were infected with scrambled shControl lentivirus carrying a red fluorescent protein reporter (shControl group). Neuronal somata and neurites were reconstructed based on the lentiviral red fluorescent protein signal. Developmental dendritic and motility changes in VGLUT1+ glutamatergic neurons and TH+ dopaminergic neurons were then evaluated in both groups. Compared with shControl VGLUT1+ neurons, the dendritic length and arborizations of shSHANK2 VGLUT1+ neurons were shorter and fewer, while cell soma speed was higher. Furthermore, dendritic length and arborization were significantly increased after insulin-like growth factor 1 treatment of shSHANK2 neurons, while cell soma speed remained unaffected. These results suggest that insulin-like growth factor 1 can rescue morphological defects, but not the change in neuronal motility. Collectively, our findings demonstrate that SHANK2 deficiency perturbs early neuronal development, and that IGF1 can partially rescue the neuronal defects caused by SHANK2 knockdown. All experimental procedures and protocols were approved by the Laboratory Animal Ethics Committee of Jinan University, China (approval No. 20170228010) on February 28, 2017.

N type silicon-rich nanocrystalline-SiN(x) ∶ H films were prepared by plasma enhanced chemical vapor deposition technique by changing NH3 flow rate. The effect of nitrogen incorporation on the microstructure and photoelectric properties of the thin films were characterized by Raman, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectra, and Hall effect measurement. The results indicated that with the increasing NH3, a phase transition from microcrystalline to amorphous silicon occured. Transmission electron microscope observation revealed that the size of silicon quantum dots could be adjusted by varying the flow rate of NH3. The microstructure order of the films reduced with increasing the flow rate of NH3, while the optical band gap increased, and the optical band tail became narrow. Meanwhile, Si—N bonds density increased and P doping was blocked. I-V testing results showed that with increasing NH3, the conductivity of films first decreased compared with nanocrystalline-Si and then increased. These behaviors reveal a competition in the mechanisms controlling the conductivity. However, with further increasing NH3, the conductivity decreased significantly due to rapid carrier recombination on the amorphous net structure.

Gallium nitride (GaN) power transistors are gaining rapid acceptance by the power electronics industry as the next generation wide bandgap (WBG) power semiconductor technology. Early direct drop-in replacement attempts of the silicon based power MOSFETs with GaN power devices either produce no significant performance improvement or even degradation in some situations. This is mainly due to the fact that the GaN power devices were not driven properly to fully exploit their true performance. In this paper, different gate driving techniques for both depletion and enhancement mode GaN power transistors are examined. In addition, the recent trends on integrated GaN pre-driver and GaN power ICs is also discussed.

Magnetotactic bacteria are a diverse group of microorganisms with the ability to use geomagnetic fields for direction sensing. This magnetotactic behavior can help microorganisms move towards favorable habitats for optimal growth and reproduction. Highly efficient genomic editing is very useful for a comprehensive understanding of the magnetotactic mechanism at the molecular level. In this study, we adapted an engineered CRISPR-cas9 system for efficient inactivation of gene in a widely used magnetotactic bacteria model strain,Magnetospirillum magneticumAMB-1. By combining an engineered nuclease-deficient Cas9 and single-guide RNA, a CRISPR interference system was successfully developed to silenceamb0994expression. More importantly, we succeeded in the construction of a singleamb0994gene deletion mutant using CRISPR-Cas9 with approximate 60-fold high efficiency compared to classical homology double-crossing replacement procedure. This mutant synthesized normally the magnetosomes, but reacted quicker and with less time than the wild-type strain to abrupt magnetic field reversals. A dynamics simulation by modelingM. magneticumAMB-1 cell as an ellipsoid showed that the difference of the motions between wild andΔamb0994is due to flagellar influence. The behavior observation being consistent with dynamics simulation indicated that Amb0994 is involved in the cellular response to magnetic torque change via controlling flagella. Besides the contribution to a better understanding of the magnetotaxis mechanism, this study demonstrates the CRISPR system as a useful genetic toolbox for high-efficiency genome editing in magnetotactic bacteria.

In this paper, an integrated smart gate driver IC with segmented output stage topology, programmable sense-FET, current sensing circuits and an on-chip stacked-based CPU for flexible digital control is presented. This IC is fabricated using TSMC's 0.18 μm BCD GEN2 process for driving a d-mode GaN power HEMT in cascode configuration. Using a segmentation technique, this IC can dynamically adjust the gate driving strength during switching transition to achieve slope control and EMI reduction. Programmable sense-FET and current sensing circuit monitor the load current for peak-current regulation. The embedded CPU can update all digital configuration bits on-the-fly. In dynamic driving mode, current spike at turn-on transition is reduced by 83% without sacrificing the switching speed. Current sensing circuit can detect peak current value and response within 5 ns. The pre-stored driving patterns can be loaded to the driving circuit in 1 μs under active driving mode.

To detect Japanese encephalitis virus (JEV) rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction (RT-PCR) detection system was developed.By aligning the full-length sequences of JEV (G1-G5), six sets of highly specific TaqMan real-time RT-PCR primers and probes were designed based on the highly conserved NS1, NS2, and M genes of JEV, which included one set for non-specific JEV detection and five sets for the detection of specific JEV genotypes. Twenty batches of mosquito samples were used to evaluate our quantitative PCR assay.With the specific assay, no other flavivirus were detected. The lower limits of detection of the system were 1 pfu/mL for JEV titers and 100 RNA copies/µL. The coefficients of variation of this real-time RT-PCR were all2.8%. The amplification efficiency of this method was between 90% and 103%.A TaqMan real-time RT-PCR detection system was successfully established to detect and differentiate all five JEV genotypes.

Seamounts are undersea mountains rising abruptly from the sea floor and interacting dynamically with underwater currents. They represent unique biological habitats with various microbial community structures. Certain seamount bacteria form conspicuous extracellular iron oxide structures, including encrusted stalks, flattened bifurcating tubes, and filamentous sheaths. To extend our knowledge of seamount ecosystems, we performed an integrated study on population structure and the occurrence of magnetotactic bacteria (MTB) that synthesize intracellular iron oxide nanocrystals in sediments of a seamount in the Mariana volcanic arc. We found Proteobacteria dominant at 13 of 14 stations, but ranked second in abundance to members of the phylum Firmicutes at the deep-water station located on a steep slope facing the Mariana-Yap Trench. Live MTB dwell in biogenic sediments from all 14 stations ranging in depth from 238 to 2,023 m. Some magnetotactic cocci possess the most complex flagellar apparatus yet reported; 19 flagella are arranged in a 3:4:5:4:3 array within a flagellar bundle. Phylogenetic analysis of 16S rRNA gene sequences identified 16 novel species of MTB specific to this seamount. Together the results obtained indicate that geographic properties of the seamount stations are important in shaping the bacterial community structure and the MTB composition.

H7N9 was a cause of significant global health concern due to its severe infection and approximately 35% mortality in humans. By screening a Fab antibody phage library derived from patients who recovered from H7N9 infections, we characterized two human monoclonal antibodies (HuMAbs), HNIgGD5 and HNIgGH8. The epitope of these two antibodies was dependent on two residues in the receptor binding site at positions V186 and L226 of the hemagglutinin glycoprotein. Both antibodies possessed high neutralizing activity.

High hydrostatic pressure (HHP) exerts severe effects on cellular processes including impaired cell division, abolished motility and affected enzymatic activities. Transcriptomic and proteomic analyses showed that bacteria switch the expression of genes involved in multiple energy metabolism pathways to cope with HHP. We sought evidence of a changing bacterial metabolism by supplying appropriate substrates that might have beneficial effects on the bacterial lifestyle at elevated pressure. We isolated a piezosensitive marine bacterium Vibrio fluvialis strain QY27 from the South China Sea. When trimethylamine N-oxide (TMAO) was used as an electron acceptor for energy metabolism, QY27 exhibited a piezophilic-like phenotype with an optimal growth at 30 MPa. Raman spectrometry and biochemistry analyses revealed that both the efficiency of the TMAO metabolism and the activity of the TMAO reductase increased under high pressure conditions. Among the two genes coding for TMAO reductase catalytic subunits, the expression level and enzymatic activity of TorA was up-regulated by elevated pressure. Furthermore, a genetic interference assay with the CRISPR-dCas9 system demonstrated that TorA is essential for underpinning the improved pressure tolerance of QY27. We extended the study to Vibrio fluvialis type strain ATCC33809 and observed the same phenotype of TMAO-metabolism improved the pressure tolerance. These results provide compelling evidence for the determinant role of metabolism in the adaption of bacteria to the deep-sea ecosystems with HHP.

The absolute and relative pool sizes of deoxyribonucleotides (dRNs) are essential in DNA replication fidelity, DNA damage and repair. We found in this study that although DNA damage induced by methyl methanesulfonate (MMS) seemed similar in cancer (HepG2) and normal (LO2) cells, more extensive alterations in ribonucleotides (RNs) and dRNs pools occurred in HepG2 cells indicating that HepG2 cells were more vigilant to DNA damage. After 10 h repair, RNs pools were still severely perturbed in LO2 cells. Compared to LO2 cells, deoxyribonucleotide triphosphates (dNTPs) pools in HepG2 cells elevated by more folds which could facilitate more efficient DNA repair and improve survival probability following DNA damage, although this should definitely lead to higher mutation rates. DNA repair was more efficient in HepG2 cells at S phase and it partly came to an end while DNA repair was still uncompleted in LO2 cells outside S phase. In conclusion, our results demonstrated that HepG2 and LO2 cells presented many differences in nucleotide metabolism, cell cycle checkpoints and DNA repair pathways in response to DNA damage, which could be potential targets for cancer treatment.

In this paper, an IGBT gate driver IC with a collector current sensing circuit and an on-chip CPU for digital control is presented. The IC is fabricated using TSMC's 0.18 μm BCD Gen-2 process. This technique is based on the unique Miller plateau relationship between the gate current and collector current (I g and I C ) for a particular gate resistance (R g ), and allows for a cycle by cycle measurement of I C during both turn-on and turn-off transients. Together with a dedicated and simple on-chip stack-based CPU, this technique can potentially provide collector current regulation without any extra discrete component. This technique only monitors the low voltage signal at the gate terminal, without the need to handle any high voltage signal on the collector/load side. Measurements have been carried out using a double pulse test setup. An accuracy within ±1 A is achieved over the current ranges between 1 to 30 A for turn-on and 1 to 50 A for turn-off.

Magnetococcus massalia strain MO-1 represents a group of fast-swimming marine magnetotactic coccoid-ovoid bacteria. They show polar magnetotaxis behavior in uniform magnetic field. MO-1 cells swim forward constantly with rare stop. When they meet obstacles, MO-1 cells could squeeze through or circumvent the obstacles. Here, we describe the methods for characterization of magnetotactic behaviors of MO-1 cells using adapted spectrophotometer and microscope mounted with magnetic fields.

Magnetococcus massalia strain MO-1 represents a group of fast-swimming marine magnetotactic coccoid-ovoid bacteria. They show polar magnetotaxis behavior in uniform magnetic field. MO-1 cells swim forward constantly with rare stop. When they meet obstacles, MO-1 cells could squeeze through or circumvent the obstacles. Here, we describe the methods for characterization of magnetotactic behaviors of MO-1 cells using adapted spectrophotometer and microscope mounted with magnetic fields.

Ethnopharmacological relevance Aloe vera (L.) Burm. f. (Aloe vera) is a common Traditional Chinese Medicine (TCM) recorded in Pharmacopoeia of the People's Republic of China (version 2015). It has been traditionally used for treatment of constipation. Aloe vera requires much attention for its safety evaluation because several studies have reported the association between oral consumption of Aloe vera and the development of colorectal cancer (CRC). However the material basis and molecular mechanism are.still less well elucidated. Although Wnt/β-catenin and Notch signaling pathway have been known to be closely related to the initiation and development of CRC, the impacts of Aloe vera on these cancerous pathways have not been completely determined yet. Aim of this study Hence, this study aimed to study the impacts of Aloe vera on the Wnt/β-catenin and Notch signaling pathway, as well as proliferation of CRC cells. Materials and methods Firstly, the effects of Aloe vera aqueous extract and its two active components (aloin and aloesin) on the Wnt/β-catenin and Notch signaling pathway were studied by luciferase reporter, RT-qPCR, western blotting and immunofluorescence assays, respectively. Furthermore, RNA sequencing analysis (RNA-seq) was then performed to verify their regulatory activities on the Wnt-related and Notch-related genes expression. Finally, their impacts on RKO cell proliferation and cell cycle phase were also evaluated via MTT assay and cell cycle analysis. Results Our results indicate that the aqueous extract of Aloe vera and its active component aloin activated the Wnt/β-catenin pathway and inhibited the Notch signaling pathway only in the presence of Wnt3a. While aloesin was characterized to directly activate the Wnt/β-catenin pathway and inhibit the Notch pathway independent of Wnt3a. Within 24h, the Aloe vera extract and its two components were failed to affect the proliferation or cell cycle phase of RKO cells. Nevertheless, in the presence of Wnt3a, the aqueous extract of Aloe vera with the concentration of 33.3 μg/ml start to promote the cell proliferation of RKO cells after 48h incubation. Conclusion In conclusion, this study showed that Aloe vera extract and its active component aloin activated the Wnt/β-catenin pathway and inhibited the Notch pathway in the presence of Wnt3a. While another active component, aloesin, activated the Wnt/β-catenin pathway and inhibited the Notch signaling pathway independent of Wnt3a. Given that Wnt/β-catenin and Notch pathway are closely associated with the progression of CRC, these findings would be helpful to better understand the colonic carcinogenicity of Aloe vera.

Summary Magnetotactic bacteria (MTB) have the unique capacity to align and swim along the geomagnetic field lines downward to the oxic–anoxic interface in chemically stratified water columns and sediments. They are most abundant within the first few centimetres of sediments below the water–sediment interface. It is unknown how MTB penetrate into the sediment layer and swim in the pocket water, while their movements are restricted by the alignment along the magnetic field lines. Here we characterized the swimming behaviour of the marine fast-swimming magnetotactic ovoid bacterium MO-1.We found that it rotates around and translates along its short body axis to the magnetic north (northward). MO-1 cells swim forward constantly for a minimum of 1770 μm without apparent stopping. When encountering obstacles, MO-1 cells squeeze through or swim southward to circumvent the obstacles. The distance of southward swimming is short and inversely proportional to the magnetic field strength. Using a magnetic shielding device, we provide direct evidence that magnetotaxis is beneficial to MO-1 growth and becomes essential at low cell density. Environmental implications of the fast-swimming magnetotactic behaviour of magnetococci are discussed.

Magnetotactic bacteria (MTB) are capable of synthesizing intracellular organelles, the magnetosomes, that are membrane-bounded magnetite or greigite crystals arranged in chains. Although MTB are widely spread in various ecosystems, few axenic cultures are available, and only freshwater Magnetospirillum spp. have been genetically analysed. Here, we present the complete genome sequence of a marine magnetotactic spirillum, Magnetospira sp. QH-2. The high number of repeats and transposable elements account for the differences in QH-2 genome structure compared with other relatives. Gene cluster synteny and gene correlation analyses indicate that the insertion of the magnetosome island in the QH-2 genome occurred after divergence between freshwater and marine magnetospirilla. The presence of a sodium-quinone reductase, sodium transporters and other functional genes are evidence of the adaptive evolution of Magnetospira sp. QH-2 to the marine ecosystem. Genes well conserved among freshwater magnetospirilla for nitrogen fixation and assimilatory nitrate respiration are absent from the QH-2 genome. Unlike freshwater Magnetospirillum spp., marine Magnetospira sp. QH-2 neither has TonB and TonB-dependent receptors nor does it grow on trace amounts of iron. Taken together, our results show a distinct, adaptive evolution of Magnetospira sp. QH-2 to marine sediments in comparison with its closely related freshwater counterparts.

Magnetotactic multicellular prokaryotes (MMPs) consist of unique microorganisms formed by genetically identical Gram-negative bacterial that live as a single individual capable of producing magnetic nano-particles called magnetosomes. Two distinct morphotypes of MMPs are known: spherical MMPs (sMMPs) and ellipsoidal MMPs (eMMPs). sMMPs have been extensively characterized, but less information exists for eMMPs. Here, we report the ultrastructure and organization as well as gene clusters responsible for magnetosome and flagella biosynthesis in the magnetite magnetosome producer eMMP Candidatus Magnetananas rongchenensis. Transmission electron microscopy and focused ion beam scanning electron microscopy (FIB-SEM) 3D reconstruction reveal that cells with a conspicuous core-periphery polarity were organized around a central space. Magnetosomes were organized in multiple chains aligned along the periphery of each cell. In the partially sequenced genome, magnetite-related mamAB gene and mad gene clusters were identified. Two cell morphologies were detected: irregular elliptical conical 'frustum-like' (IECF) cells and H-shaped cells. IECF cells merge to form H-shaped cells indicating a more complex structure and possibly a distinct evolutionary position of eMMPs when compared with sMMPs considering multicellularity.

Importance Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a frequent cause of adult-onset leukodystrophy known to be caused by autosomal dominant mutations in the CSF1R (colony-stimulating factor 1) gene. The discovery that CSF1R mutations cause ALSP led to more accurate prognosis and genetic counseling for these patients in addition to increased interest in microglia as a target in neurodegeneration. However, it has been known since the discovery of the CSF1R gene that there are patients with typical clinical and radiologic evidence of ALSP who do not carry pathogenic CSF1R mutations. These patients include those in whom the pathognomonic features of axonal spheroids and pigmented microglia have been found. Achieving a genetic diagnosis in these patients is important to our understanding of this disorder. Objective To genetically characterize a group of patients with typical features of ALSP who do not carry CSF1R mutations. Design, Settings, and Participants In this case series study, 5 patients from 4 families were identified with clinical, radiologic, or pathologic features of ALSP in whom CSF1R mutations had been excluded previously by sequencing. Data were collected between May 2014 and September 2015 and analyzed between September 2015 and February 2016. Main Outcomes and Measures Focused exome sequencing was used to identify candidate variants. Family studies, long-range polymerase chain reaction with cloning, and complementary DNA sequencing were used to confirm pathogenicity. Results Of these 5 patients, 4 were men (80%); mean age at onset of ALSP was 29 years (range, 15-44 years). Biallelic mutations in the alanyl-transfer (t)RNA synthetase 2 ( AARS2 ) gene were found in all 5 patients. Frameshifting and splice site mutations were common, found in 4 of 5 patients, and sequencing of complementary DNA from affected patients confirmed that the variants were loss of function. All patients presented in adulthood with prominent cognitive, neuropsychiatric, and upper motor neuron signs. Magnetic resonance imaging in all patients demonstrated a symmetric leukoencephalopathy with punctate regions of restricted diffusion, typical of ALSP. In 1 patient, brain biopsy demonstrated axonal spheroids and pigmented microglia, which are the pathognomonic signs of ALSP. Conclusions and Relevance This work indicates that mutations in the tRNA synthetase AARS2 gene cause a recessive form of ALSP. The CSF1R and AARS2 proteins have different cellular functions but overlap in a final common pathway of neurodegeneration. This work points to novel targets for research and will lead to improved diagnostic rates in patients with adult-onset leukoencephalopathy.

Leukoencephalopathies are a diverse group of white matter disorders that can be difficult to diagnose. Using focused and whole-exome sequencing, Lynch et al. expand the known clinical and mutational spectrum of genetic leukoencephalopathy in adulthood, and describe the frequency and clinical and radiological phenotype of the most commonly mutated genes., Leukodystrophies and genetic leukoencephalopathies are a rare group of disorders leading to progressive degeneration of cerebral white matter. They are associated with a spectrum of clinical phenotypes dominated by dementia, psychiatric changes, movement disorders and upper motor neuron signs. Mutations in at least 60 genes can lead to leukoencephalopathy with often overlapping clinical and radiological presentations. For these reasons, patients with genetic leukoencephalopathies often endure a long diagnostic odyssey before receiving a definitive diagnosis or may receive no diagnosis at all. In this study, we used focused and whole exome sequencing to evaluate a cohort of undiagnosed adult patients referred to a specialist leukoencephalopathy service. In total, 100 patients were evaluated using focused exome sequencing of 6100 genes. We detected pathogenic or likely pathogenic variants in 26 cases. The most frequently mutated genes were NOTCH3, EIF2B5, AARS2 and CSF1R. We then carried out whole exome sequencing on the remaining negative cases including four family trios, but could not identify any further potentially disease-causing mutations, confirming the equivalence of focused and whole exome sequencing in the diagnosis of genetic leukoencephalopathies. Here we provide an overview of the clinical and genetic features of these disorders in adults.

Protein translation is essential for all bacteria pathogens. It has also been a major focus of structural and functional studies and an important target of antibiotics. Here we report our attempts to biochemically reconstitute mycobacterial protein translation in vitro from purified components. This mycobacterial translation system consists of individually purified recombinant translation factors from Mycobacterium tuberculosis (M. tuberculosis), purified tRNAs and ribosomes from Mycobacterium smegmatis (M. smegmatis), and an aminoacyl-tRNA synthetase (AARS) mixture from the cell-extract of M. smegmatis. We demonstrate that such mycobacterial translation system was efficient in in vitro protein synthesis, and enabled functional comparisons of translational components between the gram-positive Mycobacterium and the gram-negative E. coli. Although mycobacterial translation factors and ribosomes were highly compatible with their E. coli counterparts, M. smegmatis tRNAs were not properly charged by the E. coli AARSs to allow efficient translation of a reporter. In contrast, both E. coli and M. smegmatis tRNAs exhibited similar activity with the semi-purified M. smegmatis AARSs mixture for in vitro translation. We further demonstrated the use of both mycobacterial and E. coli translation systems as comparative in vitro assays for small-molecule antibiotics that target protein translation. While mycobacterial and E. coli translation were both inhibited at the same IC50 by the antibiotic spectinomycin, mycobacterial translation was preferentially inhibited by the antibiotic tetracycline, suggesting that there may be structural differences at the antibiotic binding sites between the ribosomes of Mycobacterium and E. coli. Our results illustrate an alternative approach for antibiotic discovery and functional studies of protein translation in mycobacteria and possibly other bacterial pathogens.

An integrated and three-dimensional anoxic-aerobic (A/O) process is put forward. The novel A/O process is used to treat printing and dyeing wastewater with concentrated sludge of sludge concentration tank as inoculated sludge. The experiment studies the sludge properties during startup of the A/O process. The results show that the inoculated sludge has completely adapted the quality of the wastewater after operation of 54 d. The average MLSS of A tank and O tank reach 7.26 g/L and 3.69 g/L at the end of the last stage, respectively. The ratios of MLVSS to MLSS in A/O reactor are stable at 0.63 - 0.75. And the sedimentation velocity of sludge has a large-scale promotion and reaches 34.2 m/h in A tank and 25 m/h in O tank, respectively. Simultaneously, the novel A/O reactor has high biodegradability for pollutants with CODcr removal efficiency of about 70%. The results indicate that the integrated A/O process will be a better method to treat printing and dyeing wastewater.

As the main source of textile industrial pollution, printing and dyeing wastewater is usually difficult to be biodegraded. In this paper, a unique hydrolysis acidification reactor with double circulation sludge recycling system (DIC) is designed to treat simulated printing and dyeing wastewater. The results show that DIC reactor can realize quick startup with concentrated sludge of sludge concentration tank as inoculated sludge. And DIC reactor has high removal capabilities for CODcr and chroma, with efficiencies of about 70% and 60%, respectively. The sludge concentration is obviously increased. Moreover, the biodegradability of wastewater has been greatly increased to 0.38, which is favorable to the removal of organic pollutants in wastewater.