Magnetoelectric composites enjoy large magnetoelectric transfer efficiency at resonance frequency, accompanying a large phase shift. We prepared two magnetoelectric laminate composites to research ...the origin of large phase shift and magnetoelectric characteristics by electric-field-induced strain and magnetic-field-induced strain. The piezoelectric part plays a dominant role in both the direct and converse magnetoelectric resonances. The electromechanical resonance inspires direct and converse magnetoelectric resonant peaks, and results in the magnetoelectric phase shift of near π around the resonance frequency. However, the magnetostrictive part is difficult to inspire the magnetoelectric resonance and phase shift.
Several studies have highlighted the incidence of Clostridioides difficile infections (CDIs) in Taiwan and certain ribotypes have been related to severe clinical diseases. A study was conducted to ...investigate the polymerase chain reaction (PCR) ribotypes and genetic relatedness of clinical C. difficile strains collected from January 2009 to December 2015 at a hospital in northeastern Taiwan.
A modified two-step typing algorithm for C. difficile was used by combining a modified 8-plex and 3′-truncated tcdA screening PCR. In addition, MLVA typing was adopted for investigation of bacterial clonality and transmission.
Among a total of 86 strains, 24 (28%) were nontoxigenic and 62 (72%) had both tcdA and tcdB (A + B+). No tcdA-negative and tcdB-positive (A−B+) strains were identified. Binary toxin (CDT)-producing (cdtA+/cdtB+) strains were started to be identified in 2013. The 21 (34%) A+B+ clinical strains with binary toxin and tcdC deletion were identified as RT127 strains, which contained both RT078-lineage markers and fluoroquinolone (FQ)-resistant mutations (Thr82Ile in gyrA). Multiple loci variable-number tandem repeat analysis (MLVA) for phylogenetic relatedness of RT127 strains indicated that 20 of 21 strains belonged to a clonal complex that was identical to a clinical strain collected from southern Taiwan in 2011, suggestive of a clonal expansion in Taiwan.
A two-step typing method could rapidly confirm species identification and define the toxin gene profile of C. difficile isolates. The clonal expansion of RT127 strains in Taiwan indicates monitoring and surveillance of toxigenic C. difficile isolates from human, animal, and environment are critical to develop One Health prevention strategies.
The steroid hormone ecdysone and its receptor (EcR) play critical roles in orchestrating developmental transitions in arthropods. However, the mechanism by which EcR integrates nutritional and ...developmental cues to correctly activate transcription remains poorly understood. Here, we show that EcR-dependent transcription, and thus, developmental timing in Drosophila, is regulated by CDK8 and its regulatory partner Cyclin C (CycC), and the level of CDK8 is affected by nutrient availability. We observed that cdk8 and cycC mutants resemble EcR mutants and EcR-target genes are systematically down-regulated in both mutants. Indeed, the ability of the EcR-Ultraspiracle (USP) heterodimer to bind to polytene chromosomes and the promoters of EcR target genes is also diminished. Mass spectrometry analysis of proteins that co-immunoprecipitate with EcR and USP identified multiple Mediator subunits, including CDK8 and CycC. Consistently, CDK8-CycC interacts with EcR-USP in vivo; in particular, CDK8 and Med14 can directly interact with the AF1 domain of EcR. These results suggest that CDK8-CycC may serve as transcriptional cofactors for EcR-dependent transcription. During the larval-pupal transition, the levels of CDK8 protein positively correlate with EcR and USP levels, but inversely correlate with the activity of sterol regulatory element binding protein (SREBP), the master regulator of intracellular lipid homeostasis. Likewise, starvation of early third instar larvae precociously increases the levels of CDK8, EcR and USP, yet down-regulates SREBP activity. Conversely, refeeding the starved larvae strongly reduces CDK8 levels but increases SREBP activity. Importantly, these changes correlate with the timing for the larval-pupal transition. Taken together, these results suggest that CDK8-CycC links nutrient intake to developmental transitions (EcR activity) and fat metabolism (SREBP activity) during the larval-pupal transition.
Welded joints of molybdenum (Mo) and Mo alloy have high brittleness and low strength, which seriously limit its application as structural materials. In this study, Nitrogen (N) is used to strengthen ...the fusion zone (FZ) in the Mo laser beam welding joints and N is added into the FZ during a laser gas alloying process. The XPS and SEM confirm that many Mo2N phase were distributed on the surface of the grain boundary. The EBSD results indicate that Mo2N, which can be distributed at the grain boundary and inside the grain, tends to distribute more at the grain boundary. The tensile strength of joint by laser gas alloying is up to 382 MPa. Mo2N in the FZ plays the role of second phase strengthening. The presence of Mo2N in the FZ facilitates the second phase strengthening, allowing the application of Mo as a structural material.
Nanocubes and hollow cubic microcages of FeCo alloy have been synthesized in large scale by reduction of aqueous Fe2+ and Co2+ with hydrazine in the presence of poly(ethylene glycol) and cyclohexane ...at a relative low temperature, which were confirmed by X-ray powder diffraction, transmission electron microscopy, and scanning electron microscopy. The morphology and dimensions of FeCo alloy nanocrystals could be controlled by the reaction conditions such as the concentrations of cyclohexane and PEG-400, reaction time, and the molar ratio of Fe2+ to Co2+ in the solution. The concentration of iron in these particles could be varied between 17% and 56%. The highest magnetization of 211.9 emu/g was recorded for 68 ± 6 nm Fe50Co50 nanocubes. The work demonstrates that shape and size-controlled synthesis can offer a simple solution to fabricate magnetic FeCo nanocubes that are promising for single nanoparticle recording and for high performance exchange-spring nanocomposite magnetic applications.
Graphitic carbon nitride (g-C3N4) is a promising photocatalyst for solar H2 generation, but the practical application of g-C3N4 is still limited by the low separation efficiency of photogenerated ...charge carriers. Herein, we report the construction of ternary g-C3N4/graphene/MoS2 two-dimensional nanojunction photocatalysts for enhanced visible light photocatalytic H2 production from water. As demonstrated by photoluminescence and transient photocurrent studies, the intimate two-dimensional nanojuction can efficiently accelerate the charge transfer, resulting in the high photocatalytic activity. The g-C3N4/graphene/MoS2 composite with 0.5% graphene and 1.2% MoS2 achieves a high H2 evolution rate of 317 μmol h–1 g–1, and the apparent quantum yield reaches 3.4% at 420 nm. More importantly, the ternary g-C3N4/graphene/MoS2 two-dimensional nanojunction photocatalyst exhibits much higher photocatalytic activity than the optimized Pt-loaded g-C3N4 photocatalyst.
Helicobacter pylori infections are generally acquired during childhood and affect half of the global population, but its transmission route remains unclear. It is reported that H. pylori can be ...internalized into Candida, but more evidence is needed for the internalization of H. pylori in human gastrointestinal Candida and vaginal Candida.
Candida was isolated from vaginal discharge and gastric mucosa biopsies. We PCR-amplified and sequenced H. pylori-specific genes from Candida genomic DNA. Using optical and immunofluorescence microscopy, we identified and observed bacteria-like bodies (BLBs) in Candida isolates and subcultures. Intracellular H. pylori antigen were detected by immunofluorescence using Fluorescein isothiocyanate (FITC)-labeled anti-H. pylori IgG antibodies. Urease activity in H. pylori internalized by Candida was detected by inoculating with urea-based Sabouraud dextrose agar, which changed the agar color from yellow to pink, indicating urease activity.
A total of 59 vaginal Candida and two gastric Candida strains were isolated from vaginal discharge and gastric mucosa. Twenty-three isolates were positive for H. pylori 16S rDNA, 12 were positive for cagA and 21 were positive for ureA. The BLBs could be observed in Candida cells, which were positive for H. pylori 16S rDNA, and were viable determined by the LIVE/DEAD BacLight Bacterial Viability kit. Fluorescein isothiocyanate (FITC)-conjugated antibodies could be reacted specifically with H. pylori antigen inside Candida cells by immunofluorescence. Finally, H. pylori-positive Candida remained positive for H. pylori 16S rDNA even after ten subcultures. Urease activity of H. pylori internalized by Candida was positive.
In the form of BLBs, H. pylori can internalize into gastric Candida and even vaginal Candida, which might have great significance in its transmission and pathogenicity.
Reducing agricultural carbon emissions is important to enable carbon emission peaking by 2030 in China. However, China's transformation towards large-scale farming brings uncertainties to carbon ...emission reduction. This study quantifies the carbon emissions from cropping based on life cycle assessment and estimates the effects of farm size on carbon emissions using a fixed effects model. Furthermore, the variations of the carbon emissions from cropping driven by the changes in farm size in future years are projected through scenario analysis. Results demonstrate an inverted U-shaped change in total carbon emission from cropping as farm size increases, which is dominated by the changes in the carbon emission from fertilizer. Projections illustrate that large-scale farming transformation will postpone the peak year of total carbon emission from cropping until 2048 if the change in farm size follows a historical trend, although it is conducive to reducing total carbon emission in the long run. The findings indicate that environmental regulations to reduce fertilizer usages should be strengthened for carbon emission abatement in the early stage of large-scale farming transformation, which are also informative to other developing countries with small farm size.
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