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Two new eurypterids, a pterygotid Erettopterus qujingensis n. sp., and a slimoniid, Slimonia sp., are described from the upper Silurian (Pridolian) Yulongsi Formation of Yunnan Province, China. Erettopterus qujingensis n. sp. is characterized by several inversely curved ramus denticles and a metastoma with a deep notch in the center. The discovery not only extends the geographic extent of the genus Erettopterus and Slimonia from Euramerica to southwest China, but also gives insight into the similarity of ecosystem structures across the Silurian world.
To clarify nutrient supplementation usage and primary source of information among pregnant women in China.
This cross-sectional study used information on nutrient supplementation and primary source of information collected via face-to-face interviews. Data on the usage of folic acid, Ca/vitamin D, Fe, vitamins, DHA and other dietary supplements were collected. Primary source of information was categorised as family/relatives, friends/co-workers, the Internet, books/magazines, television/radio, doctors, other people and oneself.
Maternal and Child Health Hospital in Chengdu, China.
One thousand eighty-one Chinese pregnant women aged ≥20 years with singleton pregnancies.
In all three trimesters of pregnancy, usage was highest and most stable for folic acid (81·7 %), followed by vitamins (vitamin A, B-group vitamins, vitamin C and multivitamins; 75·0 %), whereas Ca/vitamin D (51·4 %) and Fe (18·1 %) usage was low, potentially indicating a deficiency risk. All supplementation usage percentages increased with pregnancy duration (P < 0·05). Notably, approximately 10 % of the pregnant women in our study did not use any nutrient supplementation, and this was especially common in early pregnancy. More than 50 % of the women reported getting information on nutrient supplementation from family members, and about 30 % reported getting this information from doctors.
Among pregnant women in China, awareness about nutrient supplementation increases as the pregnancy progresses, but some types of nutrient supplementation (such as Ca/vitamin D and Fe) remain at low levels. It is necessary to pay more attention to the health education of pregnant women in China, and the influence of family members should be emphasised.
Due to the drastic surge of COVID-19 patients, many countries are considering or already graduating health professional students early to aid professional resources. We aimed to assess outbreak-related psychological distress and symptoms of acute stress reaction (ASR) in health professional students and to characterize individuals with potential need for interventions.
We conducted a prospective cohort study of 1442 health professional students at Sichuan University, China. At baseline (October 2019), participants were assessed for childhood adversity, stressful life events, internet addiction, and family functioning. Using multivariable logistic regression, we examined associations of the above exposures with subsequent psychological distress and ASR in response to the outbreak.
Three hundred and eighty-four (26.63%) participants demonstrated clinically significant psychological distress, while 160 (11.10%) met the criterion for a probable ASR. Individuals who scored high on both childhood adversity and stressful life event experiences during the past year were at increased risks of both distress (ORs 2.00–2.66) and probable ASR (ORs 2.23–3.10), respectively. Moreover, internet addiction was associated with elevated risks of distress (OR 2.05, 95% CI 1.60–2.64) and probable ASR (OR 2.15, 95% CI 1.50–3.10). By contrast, good family functioning was associated with decreased risks of distress (OR 0.43, 95% CI 0.33–0.55) and probable ASR (OR 0.48, 95% CI 0.33–0.69). All associations were independent of baseline psychological distress.
Our findings suggest that COVID-19 related psychological distress and high symptoms burden of ASR are common among health professional students. Extended family and professional support should be considered for vulnerable individuals during these unprecedented times.
Schottky properties of Mo on diamond with fluorine- and oxygen-termination had
been investigated. Oxygen-termination was generated by aqua regia.
Fluorine-termination was generated by CF4 plasma treatment. Mo/Ni/Au
was deposited on the diamond surface as Schottky electrode, whose barrier height
was evaluated from current-voltage curve. After that, the X-ray photoelectron
spectroscopy methods were applied to calculate the Schottky barrier height of Mo
on different termination surface. The results indicated that the
fluorine-termination and oxygen-termination show different schottky
Morphologically controllable copper sulfide (CuS) nanoneedle, nanowall, and nanosheet networks on copper substrates have been fabricated by a simple, facile, and fast method based on low-temperature chemical vapor deposition through simply adjusting the reaction conditions such as the temperature and flow rate of argon gas. The compositional and structural analyses indicated that all the obtained nano-networks were single-crystalline. And their growths were possibly controlled by a solid–liquid–solid mechanism. The photocatalytic activities of the different shaped CuS nanostructures have been evaluated by their photodegradation on rhodamine B and methylene blue in aqueous phase, which revealed that in both cases the CuS nanoneedles nano-network exhibited better performance than the other two nanostructures.
In this paper we present fast response processes in dye doped liquid crystal cell with ZnSe layers on electrodes. Two-wave mixing and grating monitoring experiments were performed to characterize this liquid crystal system. With the help of photoconductive layers, the response time was reduced to a few milliseconds, which improved further the response rate in liquid crystal photorefractive system. A peak in response time versus applied voltage and unexpected oscillations in diffraction efficiency dynamics were observed, which implies unconventionally complex charge dynamics associated with SPPs excited at one of the photoconductive layer/liquid crystal interfaces.
We report the fabrication of AlGaN/GaN high electron mobility transistors (MIS-HEMTs) with a high breakdown voltage by employing a metal-insulator-semiconductor (MIS) gate structure using Si3N4 insulator. The Si3N4 films were deposited by plasma enhanced chemical vapor deposition (PECVD) as the surface passivation, interlayer films and the gate dielectric. In comparison with Schottky-gate HEMTs, the gate leakage currents of MIS-HEMTs exhibited three orders of magnitude reduction. With similar device structures, the off-state breakdown voltage of MIS-HEMTs was 1050 V with a specific on-resistance of 4.0 mΩ cm2, whereas the breakdown voltage and specific on-resistance of SG-HEMTs were 740 V and 4.4 mΩ cm2, respectively. In addition, the MIS-HEMTs exhibited little current slump in the pulsed measurements and possessed faster switch speed than Si MOSFET. We demonstrate that AlGaN/GaN MIS-HEMTs are promising not only for microwave applications but also for high power switching applications.
By utilizing a thin layer of supertwisted liquid crystal and potassium sodium strontium barium noibate crystal material with excellent pyroelectric effect, a broadband coverage optical sensing concept was proposed. Coating the pyroelectric substrate with a carbon layer of excellent absorption in the frequency range of interest, the intensity of an incident mid- or far-IR radiation can be converted to a corresponding intensity variation of a reflected near-IR beam via optical modulation of the liquid crystal film. As the result, the spatial intensity distribution of an incident mid- or far-IR radiation can thus be perceived directly by a low-cost semiconductor sensor/ sensor array. With flexible design of wave collecting arrangement, the broadband coverage sensor is suitable for viewing IR-giving objects with a large field-of-view.
Ball milling of ammonothermally synthesized GaN powders was performed in an ethanol solution for a variety of durations, resulting in average particle sizes of nanometer. The ball milled powders showed an obviously brightened color and improved dispersability, indicating reduced levels of aggregation. X-ray diffraction (XRD) peaks of the ball milled GaN powders were significantly broadened compared to those of the as-synthesized powders. The broadening of the XRD peaks was partially attributed to the reduction in the average particle size, which was confirmed through SEM analyses. On the other hand, rare earth doping of commercial GaN powders was also achieved through a ball mill assisted solid state reaction process. Rare earth salts were mixed with GaN powder by ball milling. The as-milled powders were heat treated under different conditions to facilitate the dopant diffusion. Luminescence properties of the rare earth doped GaN powders at near infrared range were investigated and the results were discussed.
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