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North-east China occupies an important geographic position for understanding the process of Neolithisation in East Asia. Although archaeologists have long debated the trajectory of change in this region, a lack of intensive survey and excavation has precluded convincing interpretations. This article presents research on the newly excavated sites of Huayang and Taoshan in the southern Lesser Khingan Mountains, with a particular focus on the lithic assemblages. Comparative and environmental analyses demonstrate the largely uniform trajectory of lithic technologies across north-east China and close correspondence with Late Glacial palaeoclimatic and palaeoenvironmental changes.
Oxidative stress is closely related to metabolic disorders, which can lead to various diseases. Nuclear factor E2-related factor 2 (Nrf2) is a central regulator of oxidative stress. Sodium butyrate (NaB) has been shown to alleviate oxidative stress and insulin resistance, yet how Nrf2 is involved in the action of NaB remains unclear. In this study, rats were rendered obese by feeding a high-fat diet for 9 weeks. NaB (300 mg/kg), which was gavaged every 2 days for 7 weeks, significantly alleviated high-fat diet-induced oxidative stress and insulin resistance. Additionally, the insulin signaling pathway in the liver was activated by NaB, associated with significant activation of Nrf2, superoxide dismutase and glutathione. Furthermore, hepatic up-regulation of Nrf2 in NaB-treated rats was associated with reduced protein content of histone deacetylase 1 and increased histone H3 acetyl K9 (H3K9Ac) modification on the Nrf2 promoter. The actions of NaB were completely abolished when Nrf2 was knocked down in vitro. Taken together, NaB acts as a histone deacetylase inhibitor to up-regulate Nrf2 expression with enhanced H3K9Ac modification on its promoter. NaB-induced Nrf2 activation stimulates transcription of downstream antioxidant enzymes, thus contributing to the amelioration of high-fat diet-induced oxidative stress and insulin resistance.
Image stitching is important for the perception and manipulation of undersea robots. In spite of a well-developed technique, it is still challenging for undersea images because of their inevitable appearance ambiguity caused by the limited light in the undersea environment, and local disturbance caused by moving objects, ocean current, etc. To get a clean and stable background panorama in the undersea environment, this paper proposes an undersea image-stitching method by introducing graph-based registration and blending procedures. Specifically, in the registration procedure, matching the features in each undersea image pair is formulated and solved by graph matching, to incorporate the structural information between features. In the blending procedure, an energy function on the indirect graph Markov random field is proposed, which takes both image consistency and neighboring consistency into consideration. Coincidentally, both graph matching and energy minimization can be mathematically formulated by integer quadratic programming problems with different constraints; the recently proposed graduated nonconvexity and concavity procedure is used to optimize both problems. Experiments on both synthetic images and real-world undersea images witness the effectiveness of the proposed method.
The Arctic is warming faster than anywhere else of comparable size on Earth, impacting global climate feedbacks and the Arctic biota. However, a warm Arctic is not novel. The Late Cretaceous fossil record of the region enables a detailed reconstruction of polar environmental conditions, and a thriving extinct ecosystem, during a previous 'hothouse’ global climate. Using leaf form (physiognomy) and tree ring characteristics we reconstruct Cenomanian to Coniacian polar thermal and hydrological regimes over an average annual cycle at eight locations in NE Russia and northern Alaska. A new high spatial resolution (∼1 km) WorldClim2 calibration of the Climate Leaf Analysis Multivariate Program (CLAMP) yields results similar to, but often slightly warmer than, previous analyses, but also provides more detailed insights into the hydrological regime through the return of annual and seasonal vapour pressure deficit (VPD), potential evapotranspiration (PET) estimates and soil moisture, as well as new thermal overviews through measures of thermicity and growing degree days. The new results confirm the overall warmth of the region, particularly close to the Arctic Ocean, but reveal strong local differences that may be related to palaeoelevation in the Okhotsk–Chukotka Volcanogenic Belt in NE Russia. While rainfall estimates have large uncertainties due to year-round wet soils in most locations, new measures of VPD and PET show persistent high humidity, but with notably drier summers at all the Arctic sites.
Suppression of stimulated Raman scattering (SRS) by means of chirped and tilted fiber Bragg gratings (CTFBGs) has become a key topic. However, research on high-power systems is still lacking due to two problems. Firstly, after the inscription, there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption. Secondly, CTFBGs can couple Stokes light from the core to the cladding and the coating, which causes serious heating in the coating of the CTFBG. Aimed at overcoming these bottlenecks, a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG. Also, a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding, which solves the problem of overheating in the coating of the CTFBG. Thereby, a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed. Further, we establish a kW-level CW oscillator to test the CTFBG. Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW, the thermal slope is lower than
, and the SRS suppression ratio is nearly 23 dB.
Proper use of personal protective equipment (PPE) is essential when facing emerging infectious diseases. Proper training methods can promote the use of the PPE correctly.
To explore the effect of the training method of sequential operation training on medical staff to master PPE penetration and removal skills, and to study the memory attenuation after training.
Fifteen medical staff with no experience of PPE operation in a hospital were trained to wear PPE in accordance with WHO standards by illustration and sequential operation method. The training included 30 minutes of theoretical teaching and 60 minutes of practical exercises. At the end of the training and 1 week after the training, the training objects were evaluated for PPE operation. A 2.5 x 2.5 cm fluorescent agent was applied on 6 parts, such as hands, chest, abdomen, and knees, to simulate contamination. After taking the PPE off, the parts of the whole body and the inner layer of clothing that were fluorescently contaminated were recorded. The whole operation process was recorded by video to evaluate whether the operation was correct. The error rates of two operations and the contamination position and frequency were compared.
The error rate of the operating PPE after training was 18.6%, rising to 31.9% after 1 week (Z=16.0, P<0.05). After the training, the average number of contaminated PPE removal was 1.96±1.56, which rose to 2.96±2.03 one month later. The difference was statistically significant (Z=8.92, P<0.05). The main vulnerable sites are the wrist, chest, abdomen, and left calf.
Illustrative sequential operation training is an important means to improve the way for medical staff to wear PPE, but it must be completed more than once to ensure that medical staff can firmly master the skills of wearing and removing PPE.
Personal protective equipment (PPE) is a necessary item in the period of unknown and high-risk emerging infectious disease. It is not only the necessary requirement of strict isolation, but also the last line of defense to protect medical staff.
Compare the differences between contaminated frequency and sites under two types of PPE doffing.
Recruited 56 health care workers (HCWs) who worked in clinical to follow the different PPE removal guidelines issued by the Chinese Center for Disease Control (CDC) and the World Health Organization (WHO) final resolution for preventing Ebola virus. Eight batches of HCWs were divided to conduct simulations of contaminated PPE removal using fluorescent lotion (Glitter Bug Potion, On Solution Pty Lt). Then we recorded the frequency and sites of contamination of personnel after removal of contaminated PPE by the method of visual observation.
According to China’s CDC process, the parts that are easily contaminated during PPE removal are: left hand and wrist (7 times), left calf (7 times), front chest center and left and right chest (6 times each) and left abdomen (5 times). Contaminated parts of the PPE process in accordance with the WHO process from high to low were: right hand and wrist (13 times), left hand and wrist (12 times), middle of the abdomen (10 times), left chest (9 times), and left abdomen (6 Times). There was no statistical difference between the two kinds of PPE piercing and removal (Z=1.177, P > 0. 05).
Under the guidance of the two processes recommended by China CDC and WHO, there was no significant difference in the frequency of pollution after removing PPE. It is speculated that the PPE recommendation processes issued by WHO and China CDC are effective for personal protection against fulminating infectious diseases.
Personal protective equipment (PPE) is a necessary item in the period of unknown and high risk emerging infectious disease. It is not only the necessary requirement of strict isolation but also the last line of defense to protect medical staff.
To determine the frequency and sites of contamination of personnel during the process of using Chinese PPE.
Recruit 56 health care workers (HCWs) who worked in front-line clinical to test PPE issued by the Chinese Center for Disease Control for preventing Ebola virus. Eight batches of HCWs were divided to conduct simulations of contaminated PPE removal using fluorescent lotion. Then the frequency and sites of contamination of personnel were recorded after removal of contaminated PPE. The method of visual observation was used to determine contamination.
The frequency of easily contaminated parts included: left hand and wrist (7 times), left calf (7 times), front chest center, left and right chest (6 times each), and left abdomen (5 times). Mistakes in the process of wearing PPE included: clothing touching the ground (20.00%), N95 air mask tightness not checked (13.33%), glove air-tightness not checked (4.44%), protective clothing zipper not checked (4.44%). Mistakes in doffing PPE included: clothes touching the ground or the inner surface is polluted (20.00%), the wrong method of removing N95 mask (14.44%), touching the pollution goggles mirror with hands (12.22%), incomplete washing steps, insufficient time and frequency of hand hygiene (11.11%).
It is necessary to carry out training on PPE donning and doffing for Chinese medical workers.
Anti-solvent treatment assisted crystallization is currently one of the most widely used methods to obtain high-quality perovskite films ascribed to its great operability. However, choosing a proper anti-solvent toward high-quality perovskite film for perovskite solar cells (PSCs) remains elusive. In this study, we qualitatively evaluate the impact of anti-solvent treatment on the grain growth and phase composition of perovskite by X-ray diffraction, scanning electron microscope, Fourier transform infrared spectrometer, and UV-vis absorption measurement, etc. The results demonstrate that the chemical groups in anti-solvents also affect the formation of perovskites, and anti-solvents with a low boiling point and good polarity contribute to the superior efficiency and reproducibility of PSCs. The device prepared using ether as an anti-solvent exhibits the best power conversion efficiency of 18.47%. The results indicate a new path toward selecting an ideal anti-solvent to improve the performance of PSCs.
The seasonality of individual influenza subtypes/lineages and the association of influenza epidemics with meteorological factors in the tropics/subtropics have not been well understood. The impact of the 2009 H1N1 pandemic on the prevalence of seasonal influenza virus remains to be explored. Using wavelet analysis, the periodicities of A/H3N2, seasonal A/H1N1, A/H1N1pdm09, Victoria and Yamagata were identified, respectively, in Panzhihua during 2006–2015. As a subtropical city in southwestern China, Panzhihua is the first industrial city in the upper reaches of the Yangtze River. The relationship between influenza epidemics and local climatic variables was examined based on regression models. The temporal distribution of influenza subtypes/lineages during the pre-pandemic (2006–2009), pandemic (2009) and post-pandemic (2010–2015) years was described and compared. A total of 6892 respiratory specimens were collected and 737 influenza viruses were isolated. A/H3N2 showed an annual cycle with a peak in summer–autumn, while A/H1N1pdm09, Victoria and Yamagata exhibited an annual cycle with a peak in winter–spring. Regression analyses demonstrated that relative humidity was positively associated with A/H3N2 activity while negatively associated with Victoria activity. Higher prevalence of A/H1N1pdm09 and Yamagata was driven by lower absolute humidity. The role of weather conditions in regulating influenza epidemics could be complicated since the diverse viral transmission modes and mechanism. Differences in seasonality and different associations with meteorological factors by influenza subtypes/lineages should be considered in epidemiological studies in the tropics/subtropics. The development of subtype- and lineage-specific prevention and control measures is of significant importance.
Nutrition therapy is considered an important treatment of burn patients. The aim of the study was to delineate the nutritional support in severe burn patients and to investigate association between nutritional practice and clinical outcomes. Severe burn patients were enrolled (n 100). In 90 % of the cases, the burn injury covered above 70 % of the total body surface area. Mean interval from injury to nutrition start was 2·4 (sd 1·1) d. Sixty-seven patients were initiated with enteral nutrition (EN) with a median time of 1 d from injury to first feed. Twenty-two patients began with parenteral nutrition (PN). During the study, thirty-two patients developed EN intolerance. Patients received an average of about 70 % of prescribed energy and protein. Patients with EN providing <30 % energy had significantly higher 28- d and in-hospital mortality than patients with EN providing more than 30 % of energy. Mortality at 28 d was 11 % and in-hospital mortality was 45 %. Multiple regression analysis demonstrated that EN providing <30 % energy and septic shock were independent risk factors for 28- d prognosis. EN could be initiated early in severe burn patients. Majority patients needed PN supplementation for energy requirement and EN feeding intolerance. Post-pyloric feeding is more efficient than gastric feeding in EN tolerance and energy supplement. It is difficult for severe burn patients to obtain enough feeding, especially in the early stage of the disease. More than 2 weeks of underfeeding is harmful to recovery.
In this paper, we review the status of the multifunctional experimental platform at the National Laboratory of High Power Laser and Physics (NLHPLP). The platform, including the SG-II laser facility, SG-II 9th beam, SG-II upgrade (SG-II UP) facility, and SG-II 5 PW facility, is operational and available for interested scientists studying inertial confinement fusion (ICF) and a broad range of high-energy-density physics. These facilities can provide important experimental capabilities by combining different pulse widths of nanosecond, picosecond, and femtosecond scales. In addition, the SG-II UP facility, consisting of a single petawatt system and an eight-beam nanosecond system, is introduced including several laser technologies that have been developed to ensure the performance of the facility. Recent developments of the SG-II 5 PW facility are also presented.
Two phases of diabase-sill-forming magmatism are recorded within the Badu anticline where magmas were emplaced into upper Palaeozoic carbonates and clastic rocks of the Youjiang fold-and-thrust belt in the SW South China Block, China. Zircons from these diabase units yield weighted mean U–Pb ages of 249.2±2.0 Ma and 187.1±3.3 Ma, and magmatic oxygen fugacity values from ‒20 to ‒6 (average of ‒12, equating to FMQ +5) and ‒20 to ‒10 (average of ‒15, equating to FMQ +2), respectively. These data indicate that the sills were emplaced during Early Triassic and Early Jurassic times. The discovery of c. 250 Ma mafic magmatism in this area was probably related to post-flood-basalt extension associated with the Emeishan mantle plume or rollback of the subducting Palaeo-Tethys slab. The c. 190 Ma diabase sills indicate that the southwestern South China Block records Early Jurassic mafic magmatism and lithospheric extension that was likely associated with a transition from post-collisional to within-plate tectonic regimes. The emplacement of diabase intrusions at depth may have driven hydrothermal systems, enabling the mobilization of elements from sedimentary rocks and causing the formation of a giant epigenetic metallogenic domain. The results indicate that high-oxygen-fugacity materials within basement rocks caused crustal contamination of the magmas, contributing to the wide range of oxygen fugacity conditions recorded by the Au-bearing Badu diabase. In addition, data from inherited xenocrystic zircons within the Badu diabase and detrital zircons from basement rocks suggest that the Neoproterozoic Jiangshao suture extends to the south of the Badu anticline.
Three-dimensional (3D) printing technology is a promising method for bone tissue engineering applications. For enhanced bone regeneration, it is important to have printable ink materials with appealing properties such as construct interconnectivity, mechanical strength, controlled degradation rates, and the presence of bioactive materials. In this respect, we develop a composite ink composed of polycaprolactone (PCL), poly(D,L-lactide-co-glycolide) (PLGA), and hydroxyapatite particles (HAps) and 3D print it into porous constructs. In vitro study revealed that composite constructs had higher mechanical properties, surface roughness, quicker degradation profile, and cellular behaviors compared to PCL counterparts. Furthermore, in vivo results showed that 3D-printed composite constructs had a positive influence on bone regeneration due to the presence of newly formed mineralized bone tissue and blood vessel formation. Therefore, 3D printable ink made of PCL/PLGA/HAp can be a highly useful material for 3D printing of bone tissue constructs.
The elastic properties and solid-solution strengthening (SSS) of the binary Ni–Co and Ni–Cr, and ternary Ni–Co–Cr alloys were investigated by the first-principles method. The results show that both Co and Cr increase lattice parameters of the binary alloys linearly. However, nonlinearity is found in compositional dependence of lattice parameters in the ternary Ni–Co–Cr alloys, that is, Co increases but decreases the lattice parameter at low and high Cr concentrations, respectively. Co increases the bulk, shear, and Young’s moduli (B, G, and E), while Cr increases B but decreases G and E in the binary alloys. In the ternary Ni–Co–Cr alloys, G and E have a similar compositional dependence to those in the binary alloys, except for B. Based on the Labusch model, the SSS parameter of Ni–Cr is larger than that of Ni–Co. The SSS effect increases significantly with Cr addition, especially at low Co concentrations in the ternary Ni–Co–Cr alloys. Meanwhile, it increases mildly with Co addition at low Cr concentrations but decreases with Co addition at high Cr concentrations.
The wetting of Cu–19Ni–5Al alloy on Ni-coated WC–8Co substrates with different coating thicknesses was investigated, and the brazing of Ni-coated WC–8Co to SAE1045 steel was performed by using the Cu–19Ni–5Al alloy as the filler metal. All the Cu–19Ni–5Al/Ni-coated WC–8Co systems present excellent wettability with a final contact angle of ∼10°. The thicknesses of the β + γ phase enriched with Co, Ni, and Al at the two joint interfaces increase and decrease with the Ni coating thickness, brazing temperature, and holding time increasing, respectively. The joint shear strength increases first and then decreases with the increase of Ni coating thickness, brazing temperature, or holding time. The maximum joint shear strength of ∼328 MPa is obtained while Ni plating for 90 min and brazing at 1210 °C × 5 min.