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The development and subsistence strategies adopted in ancient settlements are crucial to the understanding of long-term human–environmental interaction in the past. Here, we reassess the chronology of the ancient walled settlement of Sanjiao in the Hexi Corridor in northwestern China through accelerator mass spectrometry radiocarbon (AMS 14C) dating and explore the subsistence of the settlers inside through the identification of carbonized seeds and charcoal. In addition, high-resolution paleoclimate records in the Hexi Corridor and nearby regions are employed to explore the reason for the construction of Sanjiao. Our results show that Sanjiao was built around 828 cal BC and remained inhabited through 384–116 cal BC. This indicates Sanjiao is the earliest known walled settlement in the Hexi Corridor. Ancient people at Sanjiao consumed crops such as barley, broomcorn millet, and foxtail millet, and used wood from Tamarix chinensis, Tamarix, Salix, Picea, Hippophae, Betulaceae, and Poaceae as fuel. The construction date of Sanjiao correlates with climate deterioration and social upheavals in the Hexi Corridor, potentially suggesting a defensive purpose for the site.
The continental shelf strata provide information regarding sea-level fluctuation and climate changes in the Quaternary period. A 5831.47-km-long high-resolution seismic profile and borehole core (YS01) were acquired to reconstruct the evolutionary history of the strata in South Yellow Sea (SYS) during the late Pleistocene. The strata recorded three transgression events (HI, HII, and HIII) and three stages of paleochannel development (LI, LII, and LIII). Based on the distribution, thickness, and volume of the strata formed in the three transgressions, we concluded that the scale of the three transgressions during the late Pleistocene was HIII, HI, and HII, in descending order. In addition, our data show that the Yellow River extended to the Yellow Sea Trough during the last glacial maximum. The influence of the tectonic framework on sedimentation in the SYS was completely concealed by sea-level changes and sediment supply in the late Pleistocene (~Marine Isotope Stage 5). Since then, the accommodation space, a crucial prerequisite for sedimentation, has been controlled solely by sea-level changes in the SYS. Furthermore, two “source to sink” models of the neritic shelf in the marine and terrestrial environments were established, including high sea-level and shelf-exposure models.
A facile and low-cost method based for tension gradient self-assembly was developed to prepare polytetrafluoroethylene (PTFE) nanofiber coatings on stainless-steel fiber felts. The PTFE particles were used as building blocks and the self-assembly process was analyzed thoroughly. After being sintered, the PTFE particles were transformed into PTFE nanofibers. The felts coated with the PTFE nanofibers exhibited superhydrophobicity and superoleophilicity, and could separate a series of oil–water mixtures with high efficiency and good reusability. The coated felts also presented excellent chemical and thermal stabilities. Over all, this approach could easily fabricate ultra-robust oil–water separation materials suitable for industrial applications.
AgBr-modified Bi2WO6 nanosheets were successfully synthesized using a CTAB-assisted hydrothermal method followed by a facile deposition–precipitation procedure. The as-prepared photocatalysts were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET), and photoluminescence emission spectroscopy (PL). AgBr nanoparticles were found evenly distributed on the surface of the Bi2WO6 nanosheets. The AgBr/Bi2WO6 nanocomposite demonstrated enhanced pollutant decolorization efficiency in eliminating Rhodamine B (RhB), methyl orange (MO), and phenol aqueous solutions under simulated solar light irradiation. It has been noticed that the adsorption performance of both Bi2WO6 nanosheets and AgBr-modified Bi2WO6 nanosheets played a more important role in the decolorization of pollutants, such as RhB and MO, than their photocatalytic ability. The high adsorption efficiency of the photocatalysts was mainly attributed to the increased surface area and the exposed reactive facets of the materials.
Dairy cows with type II ketosis display hepatic fat accumulation and hyperinsulinemia, but the underlying mechanism is not completely clear. This study aimed to clarify the regulation of lipid metabolism by insulin in cow hepatocytes. In vitro, cow hepatocytes were treated with 0, 1, 10, or 100 nm insulin in the presence or absence of AICAR (an AMP-activated protein kinase alpha (AMPKα) activator). The results showed that insulin decreased AMPKα phosphorylation. This inactivation of AMPKα increased the gene and protein expression levels of carbohydrate responsive element-binding protein (ChREBP) and sterol regulatory element-binding protein-1c (SREBP-1c), which downregulated the expression of lipogenic genes, thereby decreasing lipid biosynthesis. Furthermore, AMPKα inactivation decreased the gene and protein expression levels of peroxisome proliferator-activated receptor-α (PPARα), which upregulated the expression of lipid oxidation genes, thereby increasing lipid oxidation. In addition, insulin decreased the very low density lipoprotein (VLDL) assembly. Consequently, triglyceride content was significantly increased in insulin treated hepatocytes. Activation of AMPKα induced by AICAR could reverse the effect of insulin on PPARα, SREBP-1c, and ChREBP, thereby decreasing triglyceride content. These results indicate that insulin inhibits the AMPKα signaling pathway to increase lipid synthesis and decrease lipid oxidation and VLDL assembly in cow hepatocytes, thereby inducing TG accumulation. This mechanism could partly explain the causal relationship between hepatic fat accumulation and hyperinsulinemia in dairy cows with type II ketosis.
SCN5A encodes sodium-channel α-subunit Nav1.5. The mutations of SCN5A can lead to hereditary cardiac arrhythmias such as the long-QT syndrome type 3 and Brugada syndrome. Here we sought to identify novel mutations in a family with arrhythmia.
Genomic DNA was isolated from blood of the proband, who was diagnosed with atrial flutter. Illumina Hiseq 2000 whole-exome sequencing was performed and an arrhythmia-related gene-filtering strategy was used to analyse the pathogenic genes. Sanger sequencing was applied to verify the mutation co-segregated in the family.
Results and conclusions
A novel missense mutation in SCN5A (C335R) was identified, and this mutation co-segregated within the affected family members. This missense mutation was predicted to result in amplitude reduction in peak Na+ current, further leading to channel protein dysfunction. Our study expands the spectrum of SCN5A mutations and contributes to genetic counselling of families with arrhythmia.
At the Shaanxi Observatory, regular observations with the prototype of the photoelectric astrolabe PAI have been carried out since 1973. Three photoelectric astrolabes of type Mark II (PAII) were mounted at the Shanghai, Beijing and Yunnan Observatories in 1974, 1976 and 1978, respectively. Details of the instruments and the results of the observation were published previously. (Photoelectric Astrolabe Developing Group 1973 and 1975, Second Group, First Divsion Shaanxi Observatory 1974, Astrolabe Data Analysis Group, First Division, Shaanxi Observatory 1975, Wang, L-j 1979, Astrolabe Group, First Division, Shanghai Observatory 1976, Wang, L-z and Luo 1979, Lu and Luo 1979). Time and latitude determinations by these sets of photoelectric astrolabes form a part in the international cooperation of BIH, IPMS as well as in the short campaign of project MERIT.
The effect of nitrogen gas addition in Ar-based double-layer shielding gas on the impact toughness of welded ultra-ferritic stainless steel during an autogenous gas tungsten arc welding (GTAW) process was investigated. The nitrogen behavior was proposed. The microstructure, mechanical properties, and fracture surface morphology of the weld metals have been evaluated. More equiaxed crystals, refined grain, narrow HAZ width, and increased microhardness were produced with nitrogen addition. Experimental findings indicated that nitrogen diffused into HAZ and dissolved into weld pool. The solute distribution was changed thus bringing significant constitutional supercooling and decreased temperature gradient of weld pool, which contributed to fine microstructure. Impact toughness at room temperature was enhanced from 2J to 9J (welds), 5J–13J (HAZ). Ductile fracture zone was produced about 0.3–0.5 mm thickness distance from the weld surface. A significant increased impact toughness of weld metal was due to the refinement of microstructure and element addition.
To explore the 3-tiered treatment model for medical treatment after an earthquake.
Based on the practices of the national emergency medical rescue services in the Lushan earthquake zone, the 3-tiered treatment classification approach was retrospectively reviewed.
Medical rescue teams assembled and reported quickly to the disaster areas after the earthquake. The number of injured people had reached 25,176 as of April 30; of these, 18,611 people were treated as outpatients, 6565 were hospitalized, and 977 were seriously or severely injured.
The 3-tiered treatment model was the main approach used by rescue services after the Lushan earthquake. Primary and secondary treatments were of the highest importance and formed the basis of the Lushan model of earthquake rescue and treatment. (Disaster Med Public Health Preparedness. 2018; 12: 301–304)
Animal studies have suggested that Mn might be associated with some components of the metabolic syndrome (MetS). A few epidemiological studies have assessed dietary Mn intake and its association with the risk of the MetS and its components among Chinese adults. In this study, we assessed daily dietary Mn intake and its relationship with MetS risk among Chinese adults in Zhejiang Province using data from the 5th Chinese National Nutrition and Health Survey (2010–2012). A total of 2111 adults were included. Dietary Mn intake was assessed using 3-d 24-h dietary recalls; health-related data were obtained by questionnaire surveys, physical examinations and laboratory assessments. The mean intake of Mn was 6·07 (sd 2·94) mg/d for men (n 998) and 5·13 (sd 2·65) mg/d for women (n 1113). Rice (>42 %) was the main food source of Mn. The prevalence of the MetS was 28·0 % (590/2111). Higher Mn intake was associated with a decreased risk of the MetS in men (Q4 v. Q1 OR 0·62; 95 % CI 0·42, 0·92; Ptrend=0·043) but an increased risk in women (Q4 v. Q1 OR 1·56; 95 % CI 1·02, 2·45; Ptrend=0·078). In addition, Mn intake was inversely associated with abdominal obesity (Ptrend=0·016) and hypertriacylglycerolaemia (Ptrend=0·029) in men, but positively associated with low HDL-cholesterol in both men (Ptrend=0·003) and women (Ptrend<0·001). Our results suggest that higher Mn intakes may be protective against the MetS in men. The inverse association between Mn intake and the MetS in women might be due to the increased risk for low HDL-cholesterol.
A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3–5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at 3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.
To determine dynamic changes in clinical characteristics by examining an outbreak of adenovirus infection that occurred from December 20, 2012, to February 25, 2013, in Tianjin, China.
Active surveillance for febrile respiratory illnesses was conducted, and medical records of patients were collected. Real-time quantitative polymerase chain reaction and sequencing were used for pathogen identification and viral genome study, respectively. Student’s t-test was used to compare the mean values of normally distributed continuous variables. Mann-Whitney U or Kruskal-Wallis tests were used if continuous variables were not normally distributed. Pearson’s chi-square test or Fisher’s exact test was used to compare categorical variables.
The outbreak was sourced from the index case diagnosed as the common cold on December 20, 2012; a total of 856 cases were reported in the following 66 days. The pathogen was identified as human adenovirus (HAdV) 55. The symptoms manifested differently in severe and mild cases. Routine blood examinations, liver function indexes, and heart function indexes showed different dynamic patterns over time in hospitalized patients.
Clinical characteristics and laboratory examinations may reveal unique patterns over the course of HAdV-55 infection. (Disaster Med Public Health Preparedness. 2018;12:464–469)
A correction method for linear hardening materials is brought forward to obtain the true (or nearly true) modulus of cylindrical specimens with middle aspect ratios in compression tests. By considering the stress concentration near the interface between the specimen and the compression platen caused by slanted contact, a “sandwich” model is developed. A correction formula is derived and all parameters can be obtained from the tested stress–strain curve. Experiments were performed on Al 2024 specimens with four aspect ratios. The corrected results are closer to the intrinsic modulus than the tested values, which verify the effectiveness of the correction method.
Two kinds of heavy-alloying β-type TiAl-based alloys Ti44Al6Nb1.0Cr2.0V (A1) and Ti44Al6Nb1.0Cr2.0V0.15Y0.1B (A2) are newly designed. They are prepared by vacuum consumable melting (VCM) and cold crucible directional solidification (CCDS). Via the theoretical analysis and tentative experiment, five alternative heat treatment (HT) schedules are proposed and studied that the corresponding microstructure and room temperature (RT) tensile property are investigated, and finally the optimized HT schedules are acquired. After HT5 (heat preservation in β phase region and at 1290 °C, and then ladder cooling), A2 alloy cast by VCM exhibits a better tensile property with average elongation of 1.20%. For the two CCDS ingots, after HT3 (mainly annealing at 1280 °C), B2 phase and (B2 + γ) blocky morphology are reduced, the columnar grains and small angle lamellas are reserved, and the tensile property also has a moderate improvement.
The effect of the intercritical temperature on the microstructure and mechanical properties of a newly developed quenching and partitioning steel using martensitic microstructure prior to the heat treatment process was studied. Such a quenching and partitioning process possessed a unique microstructure evolution, especially during intercritical annealing after prequenching. Excellent mechanical properties were obtained due to this unique multiphase microstructure. Significant amount of interlath-retained austenite was acquired and the relationship between the microstructure and work-hardening behaviors was proposed. The martensite/austenite islands increased at elevated annealing temperature, which deteriorated the total elongation and increased the tensile strength as hard constituents when it was excessive. The result indicated that the present full martensitic microstructure before the intercritical annealing is probably more suitable to an industrial application and is a better way to produce high strength steels with suitable ductility.
This paper studies the influence of inert gas additions He, Ar, Kr and Xe on breakdown voltage within dielectric barrier discharge reactor with oxygen feed gas. The density-normalized effective ionization coefficients αeff/N are calculated for inert gas/O2 mixtures, the critical reduced field E/Ncr is obtained where the electron ionization exactly balances the attachment. Adding inert gases would lead to the decreasing critical reduced field strength E/Ncr due to the enhancement of effective ionization coefficient. In addition, inert gas additions have shown to reduce the breakdown voltage. Moreover the numerical breakdown voltage values and the experimental data are plotted for the sake of comparison and results show that calculated results are in agreement with the experimental values. Parametric study offers substantial insight in plasma physics, as well as in ozone generation applications.
The driving mechanism of solar flares and coronal mass ejections is a topic of ongoing debate, apart from the consensus that magnetic reconnection plays a key role during the impulsive process. While present solar research mostly depends on observations and theoretical models, laboratory experiments based on high-energy density facilities provide the third method for quantitatively comparing astrophysical observations and models with data achieved in experimental settings. In this article, we show laboratory modeling of solar flares and coronal mass ejections by constructing the magnetic reconnection system with two mutually approaching laser-produced plasmas circumfused of self-generated megagauss magnetic fields. Due to the Euler similarity between the laboratory and solar plasma systems, the present experiments demonstrate the morphological reproduction of flares and coronal mass ejections in solar observations in a scaled sense, and confirm the theory and model predictions about the current-sheet-born anomalous plasmoid as the initial stage of coronal mass ejections, and the behavior of moving-away plasmoid stretching the primary reconnected field lines into a secondary current sheet conjoined with two bright ridges identified as solar flares.
Yellow-emitting long afterglow phosphors Sr3−xSiO5, xMF2: Eu2+, Dy3+ (0 ≤ x ≤ 0.15, M: Ba, Sr, Ca) have been prepared by high-temperature solid-state reaction method followed with rapid cooling process. Photoluminescence measurement reveals that the main emission of the phosphors locates at 575 nm, corresponding to the 4f65d1–4f7 transition of Eu2+. The introduction of alkaline earth metal fluoride effectively enhances the luminescence intensity and prolongs the afterglow time. Especially, the afterglow of the Sr2.95SiO5, 0.05BaF2: Eu2+, Dy3+ phosphor can last for 12 h. Thermal luminescence measurement shows that the trap density of Sr3SiO5: Eu2+, Dy3+ phosphor can be adjusted by adding different alkaline earth metal fluorides, which offers a feasible way to improve the afterglow properties of silicate phosphors.
Preclinical studies have suggested an anti-colorectal cancer effect of n-3 fatty acids, yet epidemiological studies have reported mixed results. The goal of the present meta-analysis was to examine the association between the dietary intake of n-3 fatty acids and colorectal cancer risk by conducting a meta-analysis of prospective cohort studies. We searched the PubMed database up to February 2012 to identify eligible studies. Either a fixed- or random-effects model was used to obtain a pooled relative risk (RR) comparing the highest intake of n-3 fatty acids with the lowest. We conducted subgroup analyses according to sex, geographic region, length of follow-up, cancer site and type of n-3 fatty acids. We included seven prospective studies in the meta-analysis, comprising 489 465 participants and 4656 incident cases. The pooled RR of colorectal cancer in relation to n-3 fatty acids was 0·98 (95 % CI 0·88, 1·09). The results from subgroup analysis indicated a significant reduced risk of colorectal cancer in relation to n-3 fatty acids among men (RR 0·87, 95 % CI 0·75, 1·00; n 4). No significant association was observed in other subgroups. There was no evidence of publication bias as suggested by Begg's test (P = 0·76) and Egger's test (P = 0·66). The present meta-analysis showed insufficient evidence of a protective effect of n-3 fatty acids on colorectal cancer risk. However, a reduced risk observed in men warrants further investigation.