In this paper, on–off switching digitization of a W-band variable gain power amplifier (VGPA) with above 60 dB dynamic range is introduced for large-scale phased array. Digitization techniques of on–off switching modified stacking transistors with partition are proposed to optimize configuration of control sub-cells. By the proposed techniques, gain control of a radio frequency variable gain amplifier (VGA) could be highly customized for both coarse and fine switching requirements instead of using additional digital-to-analog converters to tune the overall amplifier bias. The designed VGA in 130 nm SiGe has achieved switchable gain range from −46.4 to 20.6 dB and power range from −25.0 to 15.7 dBm at W band. The chip size of the fabricated VGPA is about 0.31 mm × 0.1 mm.

With the development of high-power microwave technology, the output power of the pulse generator is required more and more higher. In this paper, it is realized by increasing the output power of the module while the output impedance of the module changes little. The module of the generator is based on pulse forming network (PFN) and linear transformer (LT). Four Blumlein PFNs with arc-type configuration and 24 Ω characteristic impedance were connected symmetrically to the primary coil of the LTD and driven by two identical laser triggered spark switches to ensure four Blumlein PFNs synchronizing operation. On this basis, a two-stage high-power pulse generator based on PFN-LT is developed. The following technical parameters of the generator were achieved on a 12 Ω high-power solid resistor: output voltage amplitude of ∼250 kV and output power of ∼5.2 GW at a repetition rate of 5 Hz.

One of the most common harmful mites in edible fungi is Histiostoma feroniarum Dufour (Acaridida: Histiostomatidae), a fungivorous astigmatid mite that feeds on hyphae and fruiting bodies, thereby transmitting pathogens. This study examined the effects of seven constant temperatures and 10 types of mushrooms on the growth and development of H. feroniarum, as well as its host preference. Developmental time for the total immature stages was significantly affected by the type of mushroom species, ranging from 4.3 ± 0.4 days (reared on Pleurotus eryngii var. tuoliensis Mou at 28°C) to 17.1 ± 2.3 days (reared on Auricularia polytricha Sacc. at 19°C). The temperature was a major factor in the formation of facultative heteromorphic deutonymphs (hypopi). The mite entered the hypopus stage when the temperature dropped to 16°C or rose above 31°C. The growth and development of this mite were significantly influenced by the type of species and variety of mushrooms. Moreover, the fungivorous astigmatid mite preferred to feed on the ‘Wuxiang No. 1’ strain of Lentinula edodes (Berk.) Pegler and the ‘Gaowenxiu’ strain of P. pulmonarius (Fr.) Quél., with a shorter development period compared with that of feeding on other strains. These results therefore quantify the effect of host type and temperature on fungivorous astigmatid mite growth and development rates, and provide a reference for applying mushroom cultivar resistance to biological pest control.

This study aimed to explore the mediation effects of one-carbon metabolism (OCM) related nutrients on the association between MTHFR rs1801133 polymorphism and gestational diabetes mellitus (GDM). Folate, vitamin B12 and homocysteine (Hcy) were measured in the serum of 1254 pregnant women. Linear and logistic regressions were used to estimate the associations of OCM nutrients and MTHFR rs1801133 polymorphism with blood glucose levels and GDM risk. Mediation analysis was applied to test the mediation effects of folate, vitamin B12 and Hcy on the association of MTHFR rs1801133 polymorphism with blood glucose concentrations and GDM. Pregnant women with MTHFR rs1801133 CC genotype had higher serum folate (10·75 v. 8·90 and 9·40 ng/ml) and lower serum Hcy (4·84 v. 4·93 and 5·20 μmol/l) than those with CT and TT genotypes. Folate concentrations were positively associated with fasting plasma glucose (FPG), 1-h plasma glucose (1-h PG), 2-h plasma glucose (2-h PG) and GDM risk. Vitamin B12 levels were negatively correlated with FPG and GDM. Although no direct association was found between MTHFR rs1801133 genotypes and GDM, there were significant indirect effects of MTHFR rs1801133 CC genotype on FPG (β: 0·005; 95 % CI: 0·001, 0·013), 1-h PG (β: 0·006; 95 % CI: 0·001, 0·014), 2-h PG (β: 0·007; 95 % CI: 0·001, 0·015) and GDM (β: 0·006; 95 % CI: 0·001, 0·014) via folate. In conclusion, serum folate mediates the effect of MTHFR rs1801133 on blood glucose levels and GDM. Our findings potentially provide a feasible GDM prevention strategy via individualised folate supplementation according to the MTHFR genotypes.

A new enantiornithine, Musivavis amabilis n. gen. n. sp., is reported from the Lower Cretaceous Jehol Biota in western Liaoning, China. The new taxon is similar to the bohaiornithids in the robust subconical teeth, bluntly expanded omal ends of the furcula, caudolaterally oriented lateral trabeculae with triangular distal ends of the sternum, and a robust second pedal digit. Yet it differs from members of Bohaiornithidae in several features recalling other enantiornithine lineages, such as the acuminate rostral ramus of maxilla, the shape of the coracoid lateral margin, the presence of craniolateral processes on the sternum, the proportions of the manual phalanges, and the unspecialized third pedal ungual phalanx. A comprehensive phylogenetic analysis of Mesozoic birds shows that homoplasy significantly affects the reconstruction of enantiornithine relationships. When all phylogenetic characters are considered of equal weight, Musivavis is reconstructed in a lineage related to a radiation of large-bodied enantiornithines including Bohaiornithidae and Pengornithidae. Alternative scenarios based on progressive downweighting of the homoplastic characters support more basal placements of the pengornithids among Enantiornithes, but do not alter the affinity of Musivavis as a member of the “bohaiornithid-grade” group.

UUID: http://zoobank.org/617c7062-21ab-4d33-ae80-4edf5a129683

In the past few years, our group worked on the area of transformation from the two-dimensional (2-D) nanocrystalline films to one-dimensional (1-D) nanomaterials by using thermal oxidation. In this paper, we overview the research work on the controllable growth processes, transformation phenomena, growth mechanisms and applications. In general, the preparation process includes the following steps: 1) prepare a pure metal nanocrystalline film via a pulse electro – deposition; 2) grow variant 1-D nanomaterials, such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), and 1-D metal oxide nanoneedles involving ZnO, CuO and Fe3O4, etc. by using this film as catalyst. This process exhibits the following features: 1) the 1-D nanomaterials grow according to “base growth” model and no residual catalyst exists at the tip of the products; 2) the diameter of the 1-D nanomaterials can be controlled by controlling grain sizes of the 2-D films through adjusting pulse electro-deposition parameters; 3) it is more easily to get the 1-D nanomaterials with large area, uniform, vertical alignment and good shape on the substrates. We propose a “solid state based-up diffusion growth mechanism” for growth of the 1-D metal oxide nanoneedles, and “base growth model” for the 1-D carbon nanomaterials. The physical properties, such as Field emission and magnetics, of the 1-D metal oxide nanoneedles were studied, which showed desired values. In addition, we couple the ZnO nanoneedles with NiO, TiO2, graphene, Au nanoparticles, etc. for enhancing photocatalytic properties in the areas of environmental purification.

Bragg coherent X-ray diffraction imaging has been used to determine the structure of the initial clusters of α-Fe nano crystals which form upon annealing of an iron-based amorphous alloy or metallic glass. The method is able to identify the shapes and strain of these crystallites without any need for cutting the sample, so can visualize them in three dimensions in their intact state. In this way, the delicate dendritic structures on the exterior of the crystallites can be seen and its density versus radius relationship identifies a fractal dimension of the porous region that is consistent with diffusion-limited aggregation models. The crystal sizes were found to be around 60 nm after annealing at 700 °C growing to about 330 nm after annealing at 750 °C. This article introduces the BCDI method and describes its application to characterize previously recrystallized samples of iron-based amorphous alloys. It paves the way for a possible future in situ nucleation/growth investigation of the relationship between kinetics and nanostructure of metallic glass.

Choline and betaine are essential nutrients involved in one-carbon metabolism and have been hypothesised to affect breast cancer risk. Functional polymorphisms in genes encoding choline-related one-carbon metabolism enzymes, including phosphatidylethanolamine N-methyltransferase (PEMT), choline dehydrogenase (CHDH) and betaine-homocysteine methyltransferase (BHMT), have important roles in choline metabolism and may thus interact with dietary choline and betaine intake to modify breast cancer risk. This study aimed to investigate the interactive effect of polymorphisms in PEMT, BHMT and CHDH genes with choline/betaine intake on breast cancer risk among Chinese women. This hospital-based case–control study consecutively recruited 570 cases with histologically confirmed breast cancer and 576 age-matched (5-year interval) controls. Choline and betaine intakes were assessed by a validated FFQ, and genotyping was conducted for PEMT rs7946, CHDH rs9001 and BHMT rs3733890. OR and 95 % CI were estimated using unconditional logistic regression. Compared with the highest quartile of choline intake, the lowest intake quartile showed a significant increased risk of breast cancer. The SNP PEMT rs7946, CHDH rs9001 and BHMT rs3733890 had no overall association with breast cancer, but a significant risk reduction was observed among postmenopausal women with AA genotype of BHMT rs3733890 (OR 0·49; 95 % CI 0·25, 0·98). Significant interactions were observed between choline intake and SNP PEMT rs7946 (Pinteraction=0·029) and BHMT rs3733890 (Pinteraction=0·006) in relation to breast cancer risk. Our results suggest that SNP PEMT rs7946 and BHMT rs3733890 may interact with choline intake on breast cancer risk.

The effect of Zn, as an adjunct to antibiotics, on the treatment of severe pneumonia in young children is still under debate; therefore, we performed a meta-analysis to evaluate the therapeutic role of Zn for severe pneumonia in children younger than 5 years. PubMed, Cochrane library and Embase databases were systematically searched from inception until October 2015 for randomised-controlled trials (RCT) that assessed the effect of Zn as an adjunct to antibiotics for severe pneumonia. Random-effects model was used for calculating the pooled estimates, and intention-to-treat principle was also applied. Nine RCT involving 2926 children were included. Overall, the pooled results showed that adjunct treatment with Zn failed to reduce the time to recovery from severe pneumonia (hazard ratios (HR)=1·04; 95 % CI 0·90, 1·19; I2=39 %; P=0·58), hospital length of stay (HR=1·04; 95 % CI 0·83, 1·33; I2=57 %; P=0·74), treatment failure (relative risk (RR)=0·95; 95 % CI 0·79, 1·14; I2=20 %; P=0·58) or change of antibiotics (RR=1·07; 95 % CI 0·79, 1·45; I2=44 %; P=0·67). In addition, continuous outcomes were consistent while meta-analysed with standard mean difference, and all outcomes remained stable in intention-to-treat analysis. No significant differences were observed in the two groups between death rate, adverse events or recovery times of severe pneumonia indicators. Our results suggested that adjunct treatment with Zn failed to benefit young children in the treatment of severe pneumonia. Considering the clinical heterogeneity, baseline characteristics of children, definition of severe pneumonia and Zn supplement way should be taken into consideration in future research. This study was registered at PRESPERO as CRD42015019798.

The effect of interface tailoring by Cu coating carbon nanotubes (CNTs) on the properties of CNTs enhanced copper–tungsten (CNT/Cu–W) composites is investigated. Thermal, electrical, and mechanical properties were measured, and interfacial thermal resistance between Cu and CNT was calculated according to the thermal conductivity curves. CNTs with interface tailoring showed superior dispersion state in the Cu–W composites. When the CNT contents were lower than 0.5 vol%, homogeneous dispersion CNTs and strong interfacial bond between CNTs and Cu had a positive effect on the physical properties of CNT/Cu–W composites. Such interface modification can effectively achieve thermal and electrical conduction, as well as transfer load between CNTs and Cu in the CNT/Cu–W composites. When the CNT contents were higher than 0.5 wt%, the CNT agglomerations became the dominant factor to decrease the physical properties of the composites.

Recent evidence shows that excess nicotinamide can cause epigenetic changes in developing rats. The aim of the present study was to investigate the effects of maternal nicotinamide supplementation on the fetus. Female rats were randomised into four groups fed a standard chow diet (control group) or diets supplemented with 1 g/kg of nicotinamide (low-dose group), 4 g/kg of nicotinamide (high-dose group) or 4 g/kg of nicotinamide plus 2 g/kg of betaine (betaine group) for 14–16 d before mating and throughout the study. Fetal tissue samples were collected on the 20th day of pregnancy. Compared with the control group, the high-dose group had a higher fetal death rate, and the average fetal body weight was higher in the low-dose group but lower in the high-dose group. Nicotinamide supplementation led to a decrease in placental and fetal hepatic genomic DNA methylation and genomic uracil contents (a factor modifying DNA for diversity) in the placenta and fetal liver and brain, which could be completely or partially prevented by betaine. Moreover, nicotinamide supplementation induced tissue-specific alterations in the mRNA expression of the genes encoding nicotinamide N-methyltransferase, DNA methyltransferase 1, catalase and tumour protein p53 in the placenta and fetal liver. High-dose nicotinamide supplementation increased fetal hepatic α-fetoprotein mRNA level, which was prevented by betaine supplementation. It is concluded that maternal nicotinamide supplementation can induce changes in fetal epigenetic modification and DNA base composition. The present study raises the concern that maternal nicotinamide supplementation may play a role in the development of epigenetic-related diseases in the offspring.

In this work, a novel core–shell structured hybrid graphene oxide-encapsulated silica (GO–SiO2) was first fabricated via an electrostatic assembly between negatively charged graphene oxide (GO) sheets and positively charged sub-micro-sized silica. Then, the new kind of hybrid filler was used for the in situ preparation of poly(ethylene terephthalate) (PET)/GO–SiO2 composites. The microstructure and mechanical properties of the prepared composites were analyzed by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, dynamic mechanical analysis measurements, and tensile test. It was found that GO could be covalently assembled onto the subsized silica surface via its plenty of functional groups that can also provide strong interaction with the PET. As a result, a uniform dispersion of GO–SiO2 hybrids and enhanced interfacial adhesion as well as improved mechanical property have been evidenced. The new concept of using GO as a potent inorganic fillers surface modifier may broaden the use of GO and provides a new idea for the design and fabrication of advanced polymer composites.

This paper describes the results of an investigation of modified synthetic protocols to produce monodispersed magnetic ferrite nanoparticles, γ-Fe2O3 and Fe3O4, and their magnetic properties. The synthesis involved thermal decomposition of organometallic precursors followed by oxidation or reduction. In the synthesis of γ-Fe2O3, iron pentacarbonyl was used as the precursor and trimethylamine oxide as the oxidant. In the synthesis of Fe3O4, iron (III) acetylacetonate was reduced by 1, 2-hexadecanediol. The particle sizes ranged from 5–15 nm with high monodispersity. Results from TEM, XPS, and SQUID characterizations of these iron oxide nanoparticles are discussed.