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Accurate torque control is a critical issue in the compliant human–robot interaction scenario, which is, however, challenging due to the ever-changing human intentions, input delay, and various disturbances. Even worse, the performances of existing control strategies are limited on account of the compromise between precision and stability. To this end, this paper presents a novel high-performance torque control scheme without compromise. In this scheme, a new nonlinear disturbance observer incorporated with equivalent control concept is proposed, where the faster convergence and stronger anti-noise capability can be obtained simultaneously. Meanwhile, a continuous fractional power control law is designed with an iteration method to address the matched/unmatched disturbance rejection and global finite-time convergence. Moreover, the finite-time stability proof and prescribed control performance are guaranteed using constructed Lyapunov function with adding power integrator technique. Both the simulation and experiments demonstrate enhanced control accuracy, faster convergence rate, perfect disturbance rejection capability, and stronger robustness of the proposed control scheme. Furthermore, the evaluated assistance effects present improved gait patterns and reduced muscle efforts during walking and upstair activity.
Since the outbreak of 2019 novel coronavirus infection (2019-nCoV) in Wuhan City, China, pediatric cases have gradually increase. It is very important to prevent cross-infection in pediatric fever clinics, how identify children with fever in pediatric fever clinics, and strengthen the management of pediatric fever clinics. According to prevention and control programs, we propose the guidance on the management of pediatric fever clinics during the novel coronavirus pneumonia epidemic period, which outlines in detail optimizes processes, prevents cross-infection, health protection and disinfection of medical staff. The present consideration statement summarizes current strategies on pre-diagnosis, triage, diagnosis, treatment, and prevention of 2019-nCoV infection, which provide practical suggestions on strengthening the management of pediatric fever clinics during the novel coronavirus pneumonia epidemic period.
Coated copper sulfate (CCS) could be used as copper supplement in cows. To investigate the influences of copper sulfate (CS) and CCS on milk performance, nutrient digestion and rumen fermentation, fifty Holstein dairy cows were arranged in a randomized block design to five groups: control, CS addition (7.5 mg Cu/kg dry matter [DM] from CS) or CCS addition (5, 7.5 and 10 mg Cu/kg DM from CCS, respectively). When comparing copper source at equal inclusion rates (7.5 mg/kg DM), cows receiving CCS addition had higher yields of fat corrected milk, milk fat and protein, digestibility of DM, organic matter (OM) and neutral detergent fibre (NDF), ruminal total volatile fatty acid (VFA) concentration, activities of carboxymethyl-cellulase, cellobiase, pectinase and α-amylase, populations of Ruminococcus (R.) albus, R. flavefaciens and Fibrobacter succinogenes and liver copper content than cows receiving CS addition. Increasing CCS addition, DM intake was unchanged, yields of milk, milk fat and protein, feed efficiency, digestibility of DM, OM, NDF and acid detergent acid fibre, ruminal total VFA concentration, acetate to propionate ratio, activity of cellulolytic enzyme and populations of total bacteria, protozoa and dominant cellulolytic bacteria and concentrations of copper in serum and liver increased linearly, but ruminal propionate percentage, ammonia-N concentration, α-amylase activity and populations of Prevotella ruminicola and Ruminobacter amylophilus decreased linearly. The results indicated that supplement of CS could be substituted with CCS, and addition of CCS improved milk performance and nutrient digestion in dairy cows.
Schizotypy refers to schizophrenia-like traits below the clinical threshold in the general population. The pathological development of schizophrenia has been postulated to evolve from the initial coexistence of ‘brain disconnection’ and ‘brain connectivity compensation’ to ‘brain connectivity decompensation’.
In this study, we examined the brain connectivity changes associated with schizotypy by combining brain white matter structural connectivity, static and dynamic functional connectivity analysis of diffusion tensor imaging data and resting-state functional magnetic resonance imaging data. A total of 87 participants with a high level of schizotypal traits and 122 control participants completed the experiment. Group differences in whole-brain white matter structural connectivity probability, static mean functional connectivity strength, dynamic functional connectivity variability and stability among 264 brain sub-regions of interests were investigated.
We found that individuals with high schizotypy exhibited increased structural connectivity probability within the task control network and within the default mode network; increased variability and decreased stability of functional connectivity within the default mode network and between the auditory network and the subcortical network; and decreased static mean functional connectivity strength mainly associated with the sensorimotor network, the default mode network and the task control network.
These findings highlight the specific changes in brain connectivity associated with schizotypy and indicate that both decompensatory and compensatory changes in structural connectivity within the default mode network and the task control network in the context of whole-brain functional disconnection may be an important neurobiological correlate in individuals with high schizotypy.
The Antarctic subglacial drilling rig (ASDR) is designed to recover 105 mm-diameter ice cores up to 1400 m depth and 41.5 mm-diameter bedrock cores up to 2 m in length. In order to ensure safe and convenient drilling, drilling auxiliaries are designed to support fieldwork and servicing. These auxiliaries are subdivided into several systems for power supply, drill tripping in the borehole, ice core and chip processing, and drill servicing and maintenance. The required equipment also includes two generators, a drilling winch with a cable, logging winch with a cable, control desk, pipe handler with a fixed clamp, chip chamber vibrator, centrifuge, emergency devices and fitting and electrical tools. Additionally, several environmental protective measures such as a new liquid-tight casing with a thermal casing shoe and a bailing device for recovering drilling fluid from the borehole were designed. Most of the auxiliaries were tested during the summer of 2018–2019 near Zhongshan Station, East Antarctica while drilling to the bedrock to a depth of 198 m.
The clinical characteristics of patients with COVID-19 were analysed to determine the factors influencing the prognosis and virus shedding time to facilitate early detection of disease progression. Logistic regression analysis was used to explore the relationships among prognosis, clinical characteristics and laboratory indexes. The predictive value of this model was assessed with receiver operating characteristic curve analysis, calibration and internal validation. The viral shedding duration was calculated using the Kaplan–Meier method, and the prognostic factors were analysed by univariate log-rank analysis and the Cox proportional hazards model. A retrospective study was carried out with patients with COVID-19 in Tianjin, China. A total of 185 patients were included, 27 (14.59%) of whom were severely ill at the time of discharge and three (1.6%) of whom died. Our findings demonstrate that patients with an advanced age, diabetes, a low PaO2/FiO2 value and delayed treatment should be carefully monitored for disease progression to reduce the incidence of severe disease. Hypoproteinaemia and the fever duration warrant special attention. Timely interventions in symptomatic patients and a time from symptom onset to treatment <4 days can shorten the duration of viral shedding.
Hydrothermal carbon microsphere (HTC) is a carbon-based fluorescent material, which can be synthesized by hydrothermal carbonization of glucose. In this article, a series of 4ZnO·B2O3·H2O:Ln3+/HTC (where Ln = Eu or Tb) composites were prepared under hydrothermal conditions. The effects of the glucose concentration on the morphology, photoluminescence (PL) intensity and emission color of Zn3.64:Eu0.24[B2O7]·H2O/HTCx and Zn3.55:Tb0.3[B2O7]·H2O/HTCy were investigated. The relationship between morphology and PL intensity of composites was discussed. The results revealed that the presence of HTC did not change the original emission color of 4ZnO·B2O3·H2O:Ln3+ (where Ln = Eu or Tb) materials, but greatly increased their PL intensity, the sphere-like morphology composites have the strongest PL intensity. The Zn3.64:Eu0.24[B2O7]·H2O/HTCx and Zn3.55:Tb0.3[B2O7]·H2O/HTCy emit bright red light and green light, respectively, under respective excitation wavelengths. The present research suggests that the 4ZnO·B2O3·H2O:Ln3+/HTC (where Ln = Eu or Tb) composites may be candidates of red and green phosphors for display and lighting applications.
A new, modified version of the cable-suspended Ice and Bedrock Electromechanical Drill (IBED) was designed for drilling in firn, ice, debris-rich ice and rock. The upper part of the drill is almost the same for all drill variants and comprises four sections: cable termination, a slip-ring section, an antitorque system and an electronic pressure chamber. The lower part of the IBED comprises an auger core barrel, reamers, a core barrel for ice/debris-ice drilling and a conventional geological single-tube core barrel or custom-made double-tube core barrel. First, the short and full-scale field versions of the IBED were tested at an outdoor testing stand and a testing facility with a 12.5 m-deep ice well. Then, in the 2018–2019 summer season, the IBED was tested in the field at a site ~12 km south of Zhongshan Station, East Antarctica, and a ~6 cm bedrock core was recovered from a 198 m-deep borehole. A total of 18 d was required to penetrate the ice sheet. The retrieved core samples of blue ice, basal ice and bedrock provided valuable information regarding the Earth's paleo-environment.
The surface topology of biomaterial has a definite effect on the growth behavior of nerve cells for peripheral nerve regeneration. In this study, the silk fibroin (SF) film with different anisotropic microgroove/ridge was constructed by micropatterning technology. The effects of topologies width on the directional growth of dorsal root ganglion (DRG) neurons were evaluated. The results showed that the topological structure of the SF film with higher SF concentration was more clear and complete. The microtopography of the SF film with a concentration of 15% and a groove width of around 30 μm could effectively guide the directional growth of the nerve fibers of DRG. And nerve fibers could obviously form nerve fiber bundles which may have a certain pavement effect on the recovery of nerve function. The study indicated that the SF film with a specific width of the topological structure may have potential applications in the field of directional nerve regeneration.
Metal-halide perovskite solar cells (PSCs) have become a promising candidate for photovoltaic applications. Current popular organic hole conductors for highly efficient PSCs bring cost and stability issues, which hinder the commercialization of the PSCs. Hole-conductor-free PSCs are attracting great interest because they eliminate the adverse effects of organic hole conductors by transporting holes in the perovskite itself. In this article, we summarize recent progress in conventional, inverted, and printable mesoscopic hole-conductor-free PSCs. Specifically, we emphasize the stunning stability and scale-up manufacturing of printable hole-conductor-free PSCs, discussing their potential from laboratory to market. The causes for hole-conductor-free PSCs’ current low efficiency are also discussed, and are primarily ascribed to energy-level alignment and interface recombination. We believe that the efficiencies of hole-conductor-free PSCs can be enhanced to be comparable with hole-conductor-containing PSCs by interface modification and material design.
Current evidences on the association between hyperuricaemia and retinol intake remain inconsistent. Furthermore, no known studies have investigated the relationship between hyperuricaemia and retinol intake from animal food and plant food separately. This study aimed to assess the relationship between different sources of retinol intake and risk of hyperuricaemia among US adults.
Univariate and multivariate weighted logistic regression models and restricted cubic spline models were used to assess the associations of total, animal-derived and plant-derived retinol intakes with the risk of hyperuricaemia. Dietary retinol was measured through two 24-h dietary recall interviews. Hyperuricaemia was defined as serum uric acid level ≥7·0 and ≥6·0 mg/dl in men and women, respectively.
Data from the National Health and Nutrition Examination Survey 2009–2014 were used in this cross-sectional study.
Overall, 12 869 participants aged ≥20 years were included.
Compared with the lowest quintile, the multivariable OR of hyperuricaemia for the highest quintile intake of total, animal-derived and plant-derived retinol were 0·71 (95 % CI 0·52, 0·96), 0·76 (95 % CI 0·59, 0·96) and 0·92 (95 % CI 0·72, 1·17), respectively. The inverse association between dietary intake of total retinol and the risk of hyperuricaemia was observed in men. Dose–response analyses revealed a novel linear trend between the risk of hyperuricaemia and total, animal-derived retinol intake separately.
Our findings indicated that intakes of total and animal-derived retinol were negatively associated with hyperuricaemia in US adults.
We investigate the phased evolution and variation of the South Asian monsoon and resulting weathering intensity and physical erosion in the Himalaya–Karakoram Mountains since late Pliocene time (c. 3.4 Ma) using a comprehensive approach. Neodymium and strontium isotopic compositions and single-grain zircon U–Pb age spectra reveal the sources of the deposits in the east Arabian Sea, and show a combination of sources from the Himalaya and the Karakoram–Kohistan–Ladakh Mountains, with sediments from the Indian Peninsula such as the Deccan Traps or Craton. We interpret shifts in the sediment sources to have been forced by sea-level changes that correlate with South Asian monsoon rainfall variation since late Pliocene time. We collected 908 samples from the International Ocean Discovery Program Hole U1456A, which was drilled in the east Arabian Sea. Time series of hematite content and grain size of the sediments were examined downcore. We found South Asian monsoon precipitation and weathering intensity experienced three phases from late Pliocene time. Lower monsoon precipitation, with a lower variability and strong weathering intensity, occurred during 3.4–2.4 Ma; an increased and more variable South Asian monsoon rainfall, along with strengthened but fluctuating weathering intensity, occurred at 1.8–1.1 Ma; and a reduced rainfall with lower South Asian monsoon precipitation variability and moderate weathering intensity marked the period 1.1–0.1 Ma. Maximum entropy spectral analysis and wavelet transform show that there were orbital-dominated cycles of periods c. 100 and c. 41 ka in these proxy-based time series. We propose that the monsoon, sea level, global temperature and insolation together forced the weathering and erosion in SW Asia.
The study investigated novel wear and corrosion resistance of stainless steel and 316 stainless steel samples which were successfully prepared by laser melting deposition. Phase composition, microstructure, microhardness, wear resistance, and electrochemical corrosion resistance were studied. The experimental results showed that novel stainless steel was mainly composed of α-Fe and a few carbide phase (Cr, Fe)7C3. The microhardness of novel stainless steel was about 2.7 times greater than 316 stainless steel. Meanwhile, the specific wear rate of novel stainless steel and 316 stainless steel was 2.63 × 10−5 mm3/N m and 1.63 × 10−4 mm3/N m, respectively. The wear volume of 316 stainless steel was 6.19 times greater than novel stainless steel. The corrosion current and the corrosion potential of novel stainless steel and 316 stainless steel were 1.02 × 10−7 A/cm2 and 1.5 × 10−7 A/cm2, and −138.8 mV, −135.9 mV, respectively, in 3.5 wt% NaCl solution. Therefore, both microhardness and wear resistance of novel stainless steel were greatly improved, with high corrosion resistance.
A critical region of PTSD is the medial prefrontal cortex, which may be impaired in this disorder. Neuroimaging studies have reported reduced cortical volumes and neuronal integrity, as well as decreased function in medial prefrontal structures in this disorder.
The aim of this study is to find whether mPFC neurons have cell apoptosis, which may lead to the dysfunction of mPFC of PTSD.
The group to test apotosis was divided into SPS after1d, 4d, 7d, 14d and control group. Expression of caspase-9 and caspase-3 were detected by immunohistochemistry, immunofluorescence, western blotting and RT-PCR.
Caspase-3 was located in cytoplasm. Evaluation of Caspase-3 immunohistochemistry showed a significant increased in the SPS-1d, SPS-4d and SPS-7d compared with the normal control group, then gradually decreased in SPS-14d. Caspase-9-positive cells were expressed in the control group and the SPS groups, The positive expression was green fluorescence, which in cell body, membrane, and processes. The mRNA levels of Caspase-9 in the SPS rats were significant increased on days 1d and 4d then gradually decreased. The Caspase-3 mRNA levels peaked at SPS-7d, then decreased on SPS-14d.
The mPFC neuronal apoptosis through mintochodrial pathway would play an important role in the dysfunction of mPFC in post traumatic stress disorder patients.
To gain more comprehensive understanding of metabolic syndrome (Mets) among in general Chinese population.
Cross-sectional study. Mets was defined by three widely accepted definitions including modified Adults Treatment Panel (ATP) III criteria, International Diabetes Federation (IDF) criteria and harmonized definition. Risk factors were evaluated by using multivariate logistic regression.
Nineteen rural villages in northeast China.
The survey was conducted in September 2017 and May 2018 on 10 926 individuals.
According to modified ATP III criteria, IDF criteria and harmonised definition, the overall prevalence of Mets was 41·3 % (95 % CI 40·3, 42·2), 34·2 % (95 % CI 33·2, 35·1) and 44·1 % (95 % CI 43·1, 45·1), respectively. Females had a higher prevalence, and elevated blood pressure was the most frequent. Age, female sex, non-peasant worker, higher BMI and lower-annual income were independent risk factors of Mets in all three definitions (all ps < 0·05). Based on modified ATP III criteria and harmonised definition, heavy drinking was positively correlated with Mets. In contrast, former drinking was inversely associated with Mets.
Mets is highly prevalent in rural areas of northeast China. Its independent risk factors include higher age, female sex, non-peasantry worker, higher BMI and lower-annual income. Modified ATP III criteria and harmonised definition may be superior definitions of Mets.
The rhoptry kinase 18 of Toxoplasma gondii (TgROP18) has been identified as a key virulence factor that allows the parasite to escape from host immune defences and promotes its proliferation in host cells. Although much research is focused on the interaction between host cells and TgROP18, the development of monoclonal antibodies (mAbs) against TgROP18 has not been reported till date. To produce mAbs targeting TgROP18, two hybridomas secreting mAbs against TgROP18, designated as A1 and T2, were generated using cell fusion technology. The subtypes of the A1 and T2 mAbs were identified as IgG3 λ and IgM κ, and peptide scanning revealed that the core sequences of the antigenic epitopes were 180LRAQRRRSELVFE192 and 351NYFLLMMRAEADM363, respectively. The T2 mAb specifically reacted with both T. gondii type I and Chinese I, but not with T. gondii type II, Plasmodium falciparum or Schistosoma japonicum. Finally, the sequences of heavy chain and light chain complementarity-determining regions of T2 were amplified, cloned and characterized, making the modification of the mAb feasible in the future. The development of mAbs against TgROP18 would aid the investigation of the molecular mechanisms underlying the modulation of host cellular functions by TgROP18, and in the development of strategies to diagnose and treat Toxoplasmosis.
This chapter describes noncognitive assessments that measure skills and traits such as leadership, moral character, empathy, social consciousness, and civic responsibility that may be used in admissions decisions. The traditional measures of noncognitive factors, such as letters of recommendation, as well as more modern tools such as situational judgment tests and biodata, are described, and existing research, possible sources of bias, and concerns related to their use reviewed. Recommendations for using practice for the various assessments are discussed.