Study and Experiment on a Wheat Precision Seeding Robot

The wheat precision seeding technology provided an advanced agricultural support for the high yield of wheat. But the lack of effective agricultural machine made this technique difficult to apply widely. In this paper a wheel mobile robot to achieve the wheat precision seeding technology was designed. The kinematic model of the robot was built and simulated. And experimental study was taken under different operating conditions. Because of multiple effort factors, a quadratic orthogonal rotation combination design method was applied in the experiments, identifying the main factors by analysis. Then the field test was carried out according to the main factors. The experiment results showed that the qualified rates of seeding exceed 93% in different sowing speed. That reached the agronomic requirements of wheat precision seeding

Roll-to-Roll Manufacturing of Robust Superhydrophobic Coating on Metallic Engineering Materials

Creating a robust superhydrophobic surface on the conventional engineering materials at mass production is of great importance for self–cleaning, anti–icing, non–wetting surface and low flow resistance in industrial applications. Herein, we report a roll–to–roll strategy to create durable and robust superhydrophobic surfaces with designed micro–/nano– scale hierarchical structures on many conventional engineering materials by combining electrical discharge machining, coating of carbon nanoparticles, and followed by oil penetration and drying. The treated surface shows good superhydrophobic properties with static water contact angle of 170±2o and slide angle of 3±1o. The treated surface also exhibits good resilience and maintains the performance after tested in various harsh conditions including water flushing for several days, sand abrasion, scratching with sandpapers and corrosive solution. Significantly, the superhydrophobic surfaces also shows a high efficiency of self–cleaning properties even after oil–contamination during applications

Effects of advanced glycation end-products (AGEs) on skin keratinocytes by nuclear factor-kappa B (NF-κB) activation

Advance glycation end-products (AGEs) are produced in patients with long-term hyperglycemia metabolic disorder and responsible for multiple symptoms including impaired wound healing. This study was designed to reveal the roles and possible mechanism of AGE in diabetic wound healing. Sixteen Sprague-Dawley (SD) rats were divided into two groups randomly; the streptozotocin (STZ) induced diabetic group and the normal group. Eight weeks later, epidermal growth factor (EGF) and AGE levels, nuclear factor-kappa B (NF-κB) localization and cell viability were measured in vivo. Keratinocytes from normal skin were cultured in AGE-enriched conditional media, and the cell viability, apoptosis, adhesion and migration were detected in order to find the directed evidence between AGE and keratinocytes. AGE content was higher and NF-κB expression was more localized in the nuclear of keratinocytes in diabetic skins. AGE could inhibit normal cell growth by inducing apoptosis and arresting cell division cycle, inhibiting cell adhesion and promoting migration which might be mediated by NF-κB in vitro. Blocking NF-κB activity could reverse effects of AGE on cell proliferation and migration, but not adhesion. Therefore, AGE could damage the skin keratinocytes function in vivo and in vitro, and the activation of NF-κB is involved in this process.Key words: AGE, NF-kappaB, keratinocytes, diabetes, wound healing

The burden of skin and subcutaneous diseases: findings from the global burden of disease study 2019

BackgroundThe small number of existing integrative studies on the global distribution and burden of all types of skin and subcutaneous diseases hinders relevant comparisons.ObjectiveThis study aimed to determine the latest distribution, epidemiological differences, and factors potentially influencing each skin and subcutaneous disease and the policy implications.MethodsData on the skin and subcutaneous diseases were obtained from the Global Burden of Disease Study 2019. The incidence, disability-adjusted life years (DALYs), and deaths due to skin and subcutaneous diseases in 204 countries and regions from 1990 to 2019 were analyzed and stratified by sex, age, geographical location, and sociodemographic index (SDI). The annual age-standardized rate of change in the incidence was obtained to evaluate temporal trends.ResultsOf 4,859,267,654 (95% uncertainty interval [UI], 4,680,693,440–5,060,498,767) new skin and subcutaneous disease cases that were identified, most were fungal (34.0%) and bacterial (23.0%) skin diseases, which accounted for 98,522 (95% UI 75,116–123,949) deaths. The burden of skin and subcutaneous diseases measured in DALYs was 42,883,695.48 (95%UI, 28,626,691.71-63,438,210.22) in 2019, 5.26% of which were years of life lost, and 94.74% of which were years lived with disability. The highest number of new cases and deaths from skin and subcutaneous diseases was in South Asia. Globally, most new cases were in the 0–4-year age group, with skin and subcutaneous disease incidence slightly higher in men than in women.ConclusionFungal infections are major contributors to skin and subcutaneous diseases worldwide. Low–middle SDI states had the highest burden of skin and subcutaneous diseases, and this burden has increased globally. Targeted and effective management strategies based on the distribution characteristics of each country are, thus, required to reduce the burden of skin and subcutaneous diseases

Single-cell analysis reveals melanocytes may promote inflammation in chronic wounds through cathepsin G

During acute wound (AW) healing, a series of proper communications will occur between different epidermal cells at precise temporal stages to restore the integrity of the skin. However, it is still unclear what variation happened in epidermal cell interaction in the chronic wound environment. To provide new insights into chronic wound healing, we reconstructed the variations in the epidermal cell-cell communication network that occur in chronic wound healing via single-cell RNA-seq (scRNA-seq) data analysis. We found that the intricate cellular and molecular interactions increased in pressure ulcer (PU) compared to AW, especially the PARs signaling pathways were significantly upregulated. It shows that the PARs signaling pathways’ main source was melanocytes and the CTSG-F2RL1 ligand-receptor pairs were its main contributor. Cathepsin G (CatG or CTSG) is a serine protease mainly with trypsin- and chymotrypsin-like specificity. It is synthesized and secreted by some immune or non-immune cells. Whereas, it has not been reported that melanocytes can synthesize and secrete the CTSG. F2R Like Trypsin Receptor 1 (F2RL1) is a member of proteinase-activated receptors (PARs) that are irreversibly activated by proteolytic cleavage and its stimulation can promote inflammation and inflammatory cell infiltration. In this study, we found that melanocytes increased in pressure ulcers, melanocytes can synthesize and secrete the CTSG and may promote inflammation in chronic wounds through CTSG-F2RL1 pairs, which may be a novel potential target and a therapeutic strategy in the treatment of chronic wounds

Facile Fabrication of a Superhydrophobic Surface with Robust Micro-/Nanoscale Hierarchical Structures on Titanium Substrate

A superhydrophobic surface with robust structures on a metallic surface could improve its application in various harsh conditions. Herein, we developed a new strategy to fabricate robust micro-/nanoscale hierarchical structures with electrical discharge machining and electrochemical etching on a titanium substrate. After modification by fluorinated silane, the static water contact angle and slide angle of the surface could reach 162 ± 2° and 4 ± 1°, respectively. The superhydrophobic surfaces showed good corrosion resistance and mechanical stability after scratching with sandpapers. In addition, the superhydrophobic surfaces had good self-cleaning performance even in an acidic environment as well as the potential to be used as guiding tracks in droplet microfluidics and lab-on-a-chip systems. These results are expected to be helpful in designing the surface of liquid float gyroscope parts

Engineering of experience based trust for e-commerce

Trust is significant for sustainable development of e-commerce and has received increasing attention in e-commerce, multiagent systems (MAS), and artificial intelligence (AI). However, little attention has been given to the theoretical foundation and intelligent techniques for trust in e-commerce from a viewpoint of intelligent systems and engineering. This chapter will fill this gap by examining engineering of experience-based trust in e-commerce from the viewpoint of intelligent systems. It looks at knowledgebased trust, inference-based trust and their interrelationships with experience-based trust. It also examines scalable trust in e-commerce. It proposes a knowledge based model of trust in e-commerce and a system architecture for METSE: a multiagent system for experience-based trust in e-commerce. The proposed approach in this chapter will facilitate research and development of trust, multiagent systems, e-commerce and e-services

Optimization of Machining Parameters for Milling Zirconia Ceramics by Polycrystalline Diamond Tool

Zirconia ceramics are widely used in many fields because of their excellent physical and mechanical properties. However, there are some challenges to machine zirconia ceramics with high processing efficiency. In order to optimize parameters for milling zirconia ceramics by polycrystalline diamond tool, finite element method was used to simulate machining process based on Johnson-Cook constitutive model. The effects of spindle speed, feed rate, radial and axial cutting depth on cutting force, tool flank wear and material removal rate were investigated. The results of the simulation experiment were analyzed and optimized by the response surface method. The optimal parameter combination was obtained when the spindle speed, feed rate, radial and axial cutting depth were 8000 r/min, 90.65 mm/min, 0.10 mm and 1.37 mm, respectively. Under these conditions, the cutting force was 234.81 N, the tool flank wear was 33.40 μm when the milling length was 60 mm and the material removal rate was 44.65 mm3/min