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Electron microscopy has enabled atomic resolution imaging of matter. However, unlike optical spectroscopic imaging, traditional electron microscopes provide limited spectroscopic information in terms of their energy resolution. Only recently, owing to advances in monochromated STEM-EELS, have transmission electron microscopes (TEMs) been able to attain a high energy resolution. We recently proposed combining spectrally selective photoexcitation with HRTEM to achieve sub-nanometer scale optical imaging, a technique we called photoabsorption microscopy using electron analysis (PAMELA). To realize PAMELA-TEM experimentally, we constructed a TEM holder with an optical feedthrough, capable of photoexciting materials with different wavelengths. In this article, we describe our process for designing and fabricating an optical TEM specimen holder, highlighting important aspects of the design.
The Jueluotage area, which is located in the southern branch of the Eastern Tianshan and northeast of the Tarim Basin, represents a vital locality for investigating intracontinental reactivation induced by the tectonic events at the Eurasian plate margin. This study applies zircon and apatite (U–Th)/He and apatite fission-track thermochronology to the Jueluotage area in the Eastern Tianshan. Our data and thermal history modelling show that the Jueluotage area experienced Triassic–Early Jurassic (˜240–180 Ma) cooling, reflecting the closure of the North Tianshan Ocean and subsequent far-field effects of collision/accretion of the Qiangtang Block and Kunlun terrane. Following this period of fast cooling, a differential exhumation process occurred between the various tectonic belts in the Jueluotage area. The Aqishan–Yamansu belt was exposed at the surface during the Triassic–Early Jurassic cooling phase and experienced subsequent burial, which continued until Early Cretaceous time when a pulse of exhumation occurred. However, the major fault zones (Kanggurtag ductile shear zone and Aqikkuduk Fault) and Central Tianshan arc have remained tectonically stable since Early Jurassic time. No Cenozoic rapid cooling was recorded by the low-temperature thermochronology results in this study, indicating that much of the Jueluotage area was exhumed to the upper crust in the late Mesozoic period.
The aim of the study was to investigate the continuous changing pattern of H4K12 acetylation, and the expression levels of histone acetyltransferases (HATs) and histone deacetyltransferases (HDACs) in mouse oocytes during meiosis and after parthenogenetic activation (PA). The immunofluorescence results showed hyperacetylation of lysine-12 on histone H4 (H4K12) in the germinal vesicle (GV) oocytes that then decreased during germinal vesicle breakdown (GVBD), and disappeared in metaphase II (MII). However, it reappeared in the early 1-cell embryos derived after 4 h of PA. The expression levels of some selected HATs and HDACs also validated the changing pattern of H4K12 acetylation during meiosis and PA. In conclusion, H4K12 is deacetylated in GVBD and MII, and re-hyperacetylated after PA.
Although it is crucial to improve the treatment status of people with severe mental illness (SMI), it is still unknown whether and how socioeconomic development influences their treatment status.
To explore the change in treatment status in people with SMI from 1994 to 2015 in rural China and to examine the factors influencing treatment status in those with SMI.
Two mental health surveys using identical methods and ICD-10 were conducted in 1994 and 2015 (population ≥15 years old, n = 152 776) in the same six townships of Xinjin County, Chengdu, China.
Compared with 1994, individuals with SMI in 2015 had significantly higher rates of poor family economic status, fewer family caregivers, longer duration of illness, later age at first onset and poor mental status. Participants in 2015 had significantly higher rates of never being treated, taking antipsychotic drugs and ever being admitted to hospital, and lower rates of using traditional Chinese medicine or being treated by traditional/spiritual healers. The factors strongly associated with never being treated included worse mental status (symptoms/social functioning), older age, having no family caregivers and poor family economic status.
Socioeconomic development influences the treatment status of people with SMI in contemporary rural China. Relative poverty, having no family caregivers and older age are important factors associated with a worse treatment status. Culture-specific, community-based interventions and targeted poverty-alleviation programmes should be developed to improve the early identification, treatment and recovery of individuals with SMI in rural China.
In this paper, zircon U–Pb geochronology, major and trace elements, and Sr–Nd isotope geochemistry of the Baiyanghe dolerites in northern West Junggar of NW China are presented. The U–Pb dating of zircons from the dolerites yielded ages of 272.2±4 Ma and 276.7±6.2 Ma, which indicate the emplacement times. The dolerites are characterized by minor variations in SiO2 (46.89 to 49.07 wt%), high contents of Al2O3 (13.60 to 13.92 wt%) and total Fe2O3 (11.14 to 11.70 wt%), and low contents of MgO (2.67 to 3.64 wt%) and total alkalis (Na2O+K2O, 5.1 to 5.97 wt%, K2O/Na2O = 0.37–0.94), which indicate affinities to metaluminous tholeiite basalt. The REE pattern ((La/Sm)N = 2.25–2.34, (La/Yb)N = 7.42–8.36), V–Ti/1000 and 50*Zr–Ti/50–Sm discrimination diagrams show that these rocks are OIB-type. The high contents of Zr and Ti indicate a within-plate tectonic setting, and samples plot in the ‘plume source’ field shown on the Dy/Yb(N) versus Ce/Yb(N) diagram. The positive εNd(t) values (+7.09 to +7.48), high initial 87Sr/86Sr ratios (0.70442 to 0.70682) and depletions of Nb and Ta elements in the samples can be explained by the involvement of subducted sediments. In summary, it is possible that the Baiyanghe dolerites were derived from an OIB-like mantle source and associated with a mantle plume tectonic setting. Therefore, our samples provide the youngest evidence for the existence of a mantle plume, which may provide new insights into the Late Palaeozoic tectonic setting of West Junggar.
A function has been proposed to evaluate the electron density model constructed by inverse Fourier transform using the observed structure amplitudes and trial phase set. The strategy of this function is applying an imaginary electron density modification to the model, and then measuring how well the calculated structure amplitudes of the modified model matches the expected structure amplitudes for the modified correct model. Since the correct model is not available in advance, a method has been developed to estimate the structure amplitudes of the modified correct model. With the estimated structure amplitudes of the modified correct model, the evaluation function can be calculated approximately. Limited tests on simulated diffraction data indicate that this evaluation function may be valid at the data resolution better than 2.5 Å.
The high-cycle fatigue (HCF) behavior is significantly affected by surface roughness, especially for high strength metal FV520B-I. However, with surface roughness effect, neither the fatigue property, nor the high-cycle fatigue life model about FV520B-I with surface roughness has been reported. In this paper, designed fatigue experiment using the specimen with different surface roughness is presented to study the effectiveness of the roughness to the fatigue. The observations of the fatigue crack initiation sites and the crack propagation. Then the high cycle fatigue behavior of FV520B-I affected by surface roughness is analyzed. The existing very-high-cycle fatigue life model is not well-fit for high-cycle fatigue model of FV520B-I. A NEW high-cycle fatigue life prediction model of FV520B-I, taking surface roughness as a main effective variable is proposed. The model is built up by a comprehensive use of experimental data and the traditional fatigue modeling theory. The new finding between the fatigue strength coefficient and stress amplitude, with surface roughness, is adopted, leading to a NEW modified life prediction model. Study on fatigue model of FV520B-I with surface roughness is a very beneficial effort in fatigue theory and fatigue engineering development.
The present study aims to evaluate the antiparasitic activity of active components from Cynanchum paniculatum against Ichthyophthirius multifiliis. The antiparasitic activities of two bioassay-guided fractionationated compounds from C. paniculatum identified as Cynatratoside-A and Cynanversicoside C, by comparing spectral data (NMR and ESI-MS) with literature values, were evaluated by in vitro assay. These showed that both could kill theronts of I. multifiliis at a concentration of 10·0 mg L−1, with the median effective concentration (EC50) values of 4·6 mg L−1 and 5·2 mg L−1 for Cynatratoside-A and Cynanversicoside C, respectively. Encysted tomonts were killed at concentrations of 8·0 mg L−1 with both compounds. In vivo experiments demonstrated that fish treated with both compounds at 15·0 mg L−1 carried significantly fewer parasites than controls (P < 0·05). There were no mortalities among treated fish group compared with 75% mortality of untreated fish. Cynatratoside-A and Cynanversicoside C are therefore potential candidate drugs for use against I. multifiliis.
Salivary α-amylase (sAA) is responsible for the ‘pre-digestion’ of starch in the oral cavity and accounts for up to 50 % of salivary protein in human saliva. An accumulating body of literature suggests that sAA is of nutritional importance; however, it is still not clear how sAA is related to individual's nutritional status. Although copy number variations (CNV) of the salivary amylase gene (AMY1) are associated with variation in sAA levels, a significant amount of sAA variation is not explained by AMY1 CNV. To measure sAA responses to gustatory stimulation with citric acid, we used sAA ratio (the ratio of stimulated sAA levels to those of resting sAA) and investigated acute sAA responses to citric acid in children with normal (Normal-BMI, n 22) and low (Low-BMI, n 21) BMI. The AMY1 gene copy number was determined by quantitative PCR. We, for the first time, demonstrated attenuated acute sAA responses (decreased sAA ratio) to gustatory stimulation in Low-BMI (thinness grade 3) children compared with the Normal-BMI children, which suggest that sAA responses to gustatory stimulation may be of nutritional importance. However, child's nutritional status was not directly related to their resting or stimulated sAA levels, and it was not associated with AMY1 gene copy number. Finally, AMY1 CNV might influence, but did not eventually determine, sAA levels in children.
The present study aims to evaluate the antiparasitic activity of active components from Costus speciosus against Ichthyophthirius multifiliis. Bioassay-guided fractionation was employed to identify active compounds from C. speciosus yielding 2 bioactive compounds: Gracillin and Zingibernsis newsaponin. In-vitro assays revealed that Gracillin and Zingibernsis newsaponin could be 100% effective against I. multifiliis at concentrations of 0·8 and 4·5 mg L−1, with median effective concentration (EC50) values of 0·53 and 3·2 mg L−1, respectively. All protomonts and encysted tomonts were killed when the concentrations of Gracillin and Zingibernsis newsaponin were 1·0 and 5·0 mg L−1. In-vivo experiments demonstrated that fish treated with Gracillin and Zingibernsis newsaponin at concentrations of 1·0 and 5·0 mg L−1 carried significantly fewer parasites than the control (P<0·05). Mortality of fish did not occur in the treatment group (Zingibernsis newsaponin at 5·0 mg L−1) during the trial, although 100% of untreated fish died. Acute toxicities (LD50) of Gracillin and Zingibernsis newsaponin for grass carp were 1·64 and 20·7 mg L−1, respectively. These results provided evidence that the 2 compounds can be selected as lead compounds for the development of new drugs against I. multifiliis.
A magnetoelectric theoretical model combing piezoelectric and piezomagnetic parts about the longitudinal vibration was proposed for the laminate composite based on equivalent circuit. The model shows that the magnetoelectric voltage is relative to the thickness ratio, total thickness, frequency and loss. A simple laminate magnetoelectric composite was prepared by bonding a nickel plate and a multilayer piezoelectric vibrator together for the experimental research. The multilayer vibrator enjoys high capacitance, large effective area and low thickness, leading to a high magnetic field sensitivity of 1 mOe at the magnetoelectric field coefficient of 2.58 V/cmOe in the simple composite with nickel thickness of 0.2 mm. The model fits the resonance frequency well with the experimental results. Numerical calculation well predicates the magnetoelectric experimental behaviors, presenting a magnetoelectric maximum at about the thickness ratio 0.3 between the nickel plate and multilayer vibrators. This approach provides a method for the magnetoelectric application.
Different ferroelectric thin films and their related Metal-Semiconductor-Insulator-Metal (MSIM) structures include zinc oxide (ZnO) are studied, which can be utilized in back-gated ferroelectric field-effect transistors (FETs). The most ideal zinc oxide (ZnO) thin film prepared by sol-gel method are obtained under the pyrolysis temperature of 400°C and the annealing temperature of 600°C. The asymmetric or symmetric current-voltage characteristics of the heterostructures with ZnO are exhibited depending on different ferroelectric materials in them. The curves of drain current versus gate voltage for MSIM-structure FETs are investigated, in which obvious counterclockwise loops and a drain current switching ratio up to two orders of magnitude ate observed due to the modulation effect of remnant polarization on the channel resistance. The results also indicate the positive influences of impurity atom substitution in bismuth ferrite thin film for the MSIM-structure FETs.