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Real-time detection of apples in natural environment is a necessary condition for robots to pick apples automatically, and it is also a key technique for orchard yield prediction and fine management. To make the harvesting robots detect apples quickly and accurately in complex environment, a Des-YOLO v4 algorithm and a detection method of apples are proposed. Compared with the current mainstream detection algorithms, YOLO v4 has better detection performance. However, the complex network structure of YOLO v4 will reduce the picking efficiency of the robot. Therefore, a Des-YOLO structure is proposed, which reduces network parameters and improves the detection speed of the algorithm. In the training phase, the imbalance of positive and negative samples will cause false detection of apples. To solve the above problem, a class loss function based on AP-Loss (Average Precision Loss) is proposed to improve the accuracy of apple recognition. Traditional YOLO algorithm uses NMS (Nonmaximum Suppression) method to filter the prediction boxes, but NMS cannot detect the adjacent apples when they overlap each other. Therefore, Soft-NMS is used instead of NMS to solve the problem of missing detection, so as to improve the generalization of the algorithm. The proposed algorithm is tested on the self-made apple image data set. The results show that Des-YOLO v4 network has ideal features with a mAP (mean Average Precision) of apple detection of 97.13%, a recall rate of 90%, and a detection speed of 51 f/s. Compared with traditional network models such as YOLO v4 and Faster R-CNN, the Des-YOLO v4 can meet the accuracy and speed requirements of apple detection at the same time. Finally, the self-designed apple-harvesting robot is used to carry out the harvesting experiment. The experiment shows that the harvesting time is 8.7 seconds and the successful harvesting rate of the robot is 92.9%. Therefore, the proposed apple detection method has the advantages of higher recognition accuracy and faster recognition speed. It can provide new solutions for apple-harvesting robots and new ideas for smart agriculture.

In this paper, based on the mixture flow model, an optimized six-flux model is first established and applied to the tubular solar photocatalytic reactor. Parameters influencing photocatalyst distribution and radiation distribution at the reactor outlet, viz. catalyst concentration and circulation speed, are also analyzed. It is found that, at the outlet of the reactor, the optimized six-flux model has better performances (the energy increase by 1900% and 284%, respectively) with a higher catalyst concentration (triple) and a lower speed (one third).

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.

Density plays an important role in tree growth and development. Exploring the growth of males and females in the early stage of gender differentiation and the distribution pattern in different densities are beneficial to assess the influence earlier caused by density of the productivity and reproductive potential of dioecious plantations. We observed the numbers, distribution pattern and phenotypic traits of the males and females of Fraxinus mandshurica Rupr. in four initial densities (D1: 1.5 × 3 m; D2: 2 × 2 m; D3: 1.5 × 1.5 m; D4: 1 × 1 m). The results showed that the number of males and females gradually decreased with the increase in stand density, and they were randomly distributed in each density. With the increase in density, the total volume of males and females increased first and then decreased, and the highest value appeared in the D2 (2 × 2 m) density. The phenotypic traits of males and females had no significant difference within the same density. With increasing density, the crown width and the diameter of males and females all gradually decreased. There was a larger leaf area, larger specific leaf weight, and less leaf index for males, but for females, there was a relatively stable leaf area, larger leaf biomass, and less living under branch height. In the current stage, the D2 (2 × 2 m) planting density has advantages in the number and quality of males and females. Our results emphasize that suitable stand density can promote the volume of timber accumulation and reproduction of males and females in plantations with dioecious trees.

The present guideline on sublingual immunotherapy (SLIT) for allergic rhinitis (AR) and allergic asthma (AS) has been developed by a panel of experts on behalf of the Chinese Society of Allergy to guide the clinical practice of SLIT in China. The panel included eminent clinical physicians and scientific specialists, who majored in the fields of Otolaryngology, Respirology, Pediatrics, Allergy and Clinical Immunology, and focused their investigations on two common allergic airway diseases (namely AR and AS) in China. During the past few decades, AR and AS have shown increasing prevalence worldwide, and resulted in substantial direct and indirect costs (1).

Mobile edge computing (MEC) is powerful for providing services with ultra-low latency and extremely high reliability to support newly emerging applications in 5G and beyond by leveraging network function virtualization (NFV) where each mobile user requests a service function chain (SFC). To guarantee the quality of experience (QoE), e.g., reduce the downtime of moving users, effective placement of virtual network functions (VNFs) in MEC networks is critical to cope with the user mobility. Placing multiple instances of SFC for each user is promising for reducing the downtime during moving. However, an extremely high resource cost is induced. Towards this challenge, this paper investigates the mobility-aware multi-instance (MAMI) VNF placement problem in MEC networks. According to the empirical probabilities that one user stays within the coverage of different edge nodes, both static and dynamic SFC instances are placed to balance the tradeoff between the downtime and resource cost. A MAMI VNF placement algorithm is proposed for resource cost minimization, where resource sharing among the SFC instances of each user is allowed to further reduce resource cost. Simulation results based on real-world-like moving users show the effectiveness of our proposed algorithm.

Conservation of natural resources is a vital and challenging task. Numerous animal genetic resources have been effectively conserved worldwide. However, the effectiveness of conservation programmes and the variation information of species have rarely been evaluated. Here, we performed whole-genome and whole-genome bisulfite sequencing of 90 Chinese indigenous chickens, which belonged to the Tibetan, Wenchang and Bian chicken breeds, and have been conserved under different conservation programmes. We observed that low genetic diversity and high DNA methylation variation occurs during ex situ in vivo conservation, while higher genetic diversity and differentiation occurs during in situ conservation. Further analyses revealed that most DNA methylation signatures are unique within ex situ in vivo conservation. Moreover, a high proportion of differentially methylated regions is found in genomic selection regions, suggesting a link between the effects of genomic variation and DNA methylation. Altogether our findings provide valuable information about genetic and DNA methylation variations during different conservation programmes, and hold practical relevance for species conservation.

Aim: Multicenter study to investigate the safety of mite extract product Novo-Helisen Depot, Strengths 1 to 3 (NHD3), as subcutaneous immunotherapy (SCIT), in Chinese children and adolescents with allergic rhinitis (AR) and allergic asthma (AA). Patients & methods: We evaluated SCIT-related adverse events (AEs) during NHD3 14-week initial therapy in children (5–11 years) and adolescents (12–17 years) with perennial symptomatic AR and AA. Results: Among 3600 injections in 250 patients, 361/3600 (10.0%) injections caused SCIT-related AEs in 96/250 (38.4%) patients, 321/3600 injections (8.9%) caused local reactions in 89/250 (35.6%) and 40/3600 injections (1.1%) caused systemic reactions in 23/250 (9.2%). Conclusion: Initial SCIT treatment using NHD3 was safe and well tolerated in Chinese children and adolescents with AR and AA.

The disturbance of water flow to the remotely operated vehicle (ROV) is still a challenging problem, especially when the robot grabs and moves. This paper presents an anti-interference control method of particle swarm optimization (PSO) fuzzy PID. In the control process, the fuzzy PID controller adjusts the PID parameters online according to the actual situation of the system state. Experimental and simulation results show that the anti-interference control based on PSO fuzzy PID is more adaptive, robust and anti-interference than PID control and fuzzy PID control. This method can also be extended to other applications.

Background: Artemisia annua is the most common outdoor aeroallergen throughout Northern China; however, no multicenter study has investigated sublingual immunotherapy (SLIT) as a treatment option for Artemisia annua-induced allergic rhinitis (AR). The aim of this study was to evaluate the efficacy and safety of an innovative SLIT for Artemisia annua-related AR. Methods: This was a randomized, double-blind, placebo-controlled, multicenter, phase 3 clinical trial conducted in China (NCT XXX). A total of 702 Artemisia annua-sensitized eligible patients were randomized in a ratio of 2:1 to receive Artemisia annua-SLIT or placebo. The treatment lasted 32 weeks; including 5-weeks up-dosing phase and 27-weeks maintenance phase. The primary endpoint was the daily combined score of medication and rhinoconjunctivitis symptom (CSMRS), and secondary endpoints were daily total nasal symptom score (dTNSS) and daily rescue medication score (dRMS) during peak pollen period. Safety of treatment was evaluated according to adverse events (AEs) experienced. Results: Mean daily CSMRS was significantly improved during the peak pollen period in the SLIT group compared with the placebo group (1.46 ± 0.47 vs 1.88 ± 0.42, P

Photocatalytic water splitting for hydrogen production provides a promising route for the future hydrogen economy, being operational in the visible light domain with a potential use of solar radiation. An outdoor pilot demonstration of CPC-based photoreactors has been designed, installed and tested at the State Key Laboratory of Multiphase Flow in Power Engineering to assess its effectiveness in solar photocatalytic hydrogen production. Nine sets of CPC-based photoreactors, each of which is 3.6 m2 in area and 23 L in volume, are connected, controlled and operated in parallel. The high efficiency photocatalyst (Cd1-xZnxS), low concentration sacrifice agents (Na2S and Na2SO3) and deionized water are the raw materials of the pilot system. Two operation models, viz. the natural circulation model and the gas disturbance model, are proposed considering the expense and the efficiency. From our observations, the slurry temperature inside the tubes rises by 20–30 °C from the ambient. The slurry velocity can reach 1.2 m/s in the gas disturbance model, but is as low as 3.5 cm/s in the natural circulation model. The average hydrogen productivity is 184.30 mL/min and accumulated to be 10.321 L/h in the natural circulation model, with the average solar radiation, photocatalyst concentration and sacrifice agents' concentration being 803.8 W/m2, 2.77 g/L and 0.1 mol/L, respectively.

A novel CPC reactor for solar photocatalytic hydrogen production was designed and evaluated in the present study. Two operation models, namely the natural circulation model and the gas disturbance model, are proposed and illustrated from the viewpoints of thermodynamics and hydrodynamics. The designed photoreactor is operated under natural circulation for most of the time, with high pressure gas disturbing the sedimentary photocatalysts from time to time. The CPC parameters are designed according to the local meteorological conditions. The reactor performance such as the radiation distribution on the absorber tube, the absorbed solar irradiation, the critical flow rates and the hydrogen productivity are estimated and analyzed. An east-west orientated, north-south angle adjustable and truncated CPC with the concentration ratio of 4.12 is designed for the photoreactor. The required limiting settling velocity is much larger than the natural circulation velocity, which validates the necessity of gas disturbance. The estimated results show that the ideal mean hydrogen productivities are 2.9 L/h and 4.0 L/h in a typical spring and summer week respectively, with the photocatalyst being Cd0.5Zn0.5S.

The effective absorption of photons by photocatalyst in the reactor is a challenge for scaled-up application of a photocatalytic hydrogen production system. The spatial distribution of radiation and photon absorption are proposed to be strongly dependent on the photocatalyst concentration and the structure of the solar collector. However, there have been few reports of the radiation absorption properties of a cylindrical reactor based on high power solar collector that is suitable for a large-scale photocatalytic hydrogen production system. In this study, the distribution of radiation in the reactor as represented by the local volumetric rate of photon absorption was determined by adopting the modified six-flux absorption scattering model based on the compound parabolic concentrator and the surface uniform concentrator. The explanations of the differences of radiation absorption properties were comprehensively analyzed by ray-tracking technique. The structure of the solar collector and the optimum catalyst concentration are recommended based on photon absorption efficiency. This work may serve as potential reference values for the optimal reactor operating parameters for large-scale application.

Coke deposition is a critical issue for catalysts in tar reforming. Steam is conducive to tar removal and hydrogen production in biomass pyrolysis, while its effect on coke formation is not well known. Thus, a two-stage fluidized bed/fixed bed reactor was used to study the effect of steam addition on coke deposition. The primary conclusions are as follows: combining steam and biochar, the tar removal efficiency is more than 90% within 20 min of time on stream (TOS). After the TOS reaches 30 min, the biochar surface is saturated with coke deposition and the specific surface area of the biochar stops decreasing. The addition of steam leads to a reduction in the combustion reactivity of the biochar. Besides, the aromatization of the biochar increase and the number of O-containing structures decreases. For the tar, the addition of steam reduces the aliphatics content and increases the O-containing aromatics content. For the gas composition, the addition of steam results in the decrease of CH4 yield while the H2 yield increases to 0.12 L/g. The H/C atomic ratio of the gas composition decreases while the O/C atomic ratio increases. The active coke is consumed and decomposed after the introduction of steam. The remaining coke is dominated by inert coke. This contributes to the relatively developed pore structure but a weakened combustion reactivity of biochar.

Coal-derived carbon black is the main composition of PM2.5, used in the rubber industry and energy storage fields. The formation and structure control of carbon black have attracted significant attention. Alkali metals have influence on the dynamic formation of coal-derived carbon black. To analyze the mechanism of Na in the formation of carbon black, a high-temperature drop tube furnace was used to analysis of carbon black from the pyrolysis of acid-washed coal and Na-containing coal at 1250 °C. DFT was applied to simulate the stepwise inhibitory effect of Na on the polymerization of PAHs into carbon black. The results show that Na promotes the oxidative cracking of large PAHs into small PAHs during the formation of coal-derived carbon black (reaction energy barrier is reduced by 17.7%), and inhibits the condensation of small PAHs molecules to form carbon black molecules (reaction energy barrier is increased by 74.7%), which causes the length of carbon black is shortened by 14.3%, and its curvature is increased by 1.7%. Na could change the spatial structure of formed carbon black-graphite crystallites, which increases the spacing of carbon black by approximately 6.2% to 16.3%. Na enhances the electrochemical performance of carbon black by 2 to 3 times.

Background: The prevalence rates of allergic rhinitis (AR) and asthma in the border region of China may be different from those in the central region of plateau grasslands. A survey was performed to investigate the prevalence and risk factors for AR, asthma, and AR combined with asthma among adults (age ≥ 20 years) residing in the southern border of plateau grasslands in northern China. Methods: From May to August 2018, a cross-sectional survey was completed by subjects that were selected using a cluster random sampling method. The subjects completed a questionnaire and were administered skin prick tests (SPTs). Risk factors for AR, asthma, and AR combined with asthma were examined by multivariate logistic regression analyses. Results: A total of 1815 adult subjects in the selected region completed study. The prevalence rates of physician-diagnosed AR, asthma, and AR combined with asthma were 13.9% (253), 9.8% (177), and 2.9% (52), respectively. Among the patients with AR, 20.6% were found to have concurrent asthma; among the patients with asthma, 29.4% were found to have concurrent AR. Artemisia and Humulus pollen were the most common sensitizing pollen types. Approximately 70% of subjects with AR and 40 years old, family history of asthma, moderate-to-severe AR, adverse food reactions, and mold allergies were independent risk factors for AR combined with asthma. Conclusions: This study identified the prevalence rates of AR and asthma in the southern borders of the plateau grassland in northern China (>1500 m above sea level). Sensitization pollen is an independent risk factor for AR and AR combined with asthma.

Radiation absorption in photocatalytic reactors is usually simulated using the Monte Carlo (MC) stochastic method. In this article, MC is coupled with three different scattering phase functions: isotropic (ISO) phase function, diffuse reflecting large sphere (DR) phase function and Henyey–Greenstein (HG) phase function. Here, the model accuracy is examined via adequate experiments. The results show that phase function plays an important role in MC method. HG phase function is superior to ISO and DR phase functions because of small errors (less than 5%), and the value of the characteristic parameter g should be 0.64. The simulate results show that the absorption of solar radiation relates strongly to geometry configuration of reactors and catalyst concentration. The solar surface uniform concentrator (SUC) has a 9.94 times higher radiation absorption than the tubular reactor and realizes a uniform radiation distribution. The optimal catalyst concentrations of the SUC and the tubular reactor are 0.53 g/L and 0.68 g/L respectively.

The feasibility of solar hydrogen production from water has long relied on the activity and stability of a given photocatalyst. In this study, using Cd x Zn 1-x S as a model photocatalyst, we demonstrated that the activity and stability of chalcogenide photocatalyst could be readily adjusted by changing the reaction conditions, including sacrificial reagents, reaction temperature. Our results showed that the combined use of proper sacrificial reagents play a key role against photocorrosion. Under optimized reaction conditions, the photocatalyst remained stable for more than 500 h. Under irradiation from a simulated sun light (light intensity: 789.92 W/m 2 ), the average rate of hydrogen evolution reached 1.43 mmol/h with an energy conversion efficiency from solar to hydrogen of 6.22%.

A new compound parabolic concentrator (CPC) for solar photocatalytic hydrogen production has been designed and estimated in the present study. Parameters of the CPC, i.e., the orientation, the acceptance angle and the absorber tube diameter are designed according to the local meteorological conditions. A north-south orientated, adjustable, single axis tracking truncated CPC with the concentration ratio of 4.22 is designed as one unit. An experimental system including 76 units with the total light area of 103.7m 2 is developed and installed. The units have four different angles with inclination being 25°, 35°, 45° and 55°, respectively. The system is operated under the natural circulation condition for most of the time, with high pressure gas perturbing the sedimentary photocatalysts from time to time. NiS-Cd x Zn 1−x S is used as the photocatalyst. Preliminary results show that the mean hydrogen productivity and cumulative hydrogen generation are 7.14 NL/h and 42.84 NL/day of the horizontal angle 25° row on a typical meteorological day. The average energy conversion efficiency is 0.087%. The daily hydrogen generation of the whole system is accumulated to be 160.34 NL.

Introduction: Laryngeal squamous cell carcinoma (LSCC) is a highly aggressive malignant cancer, but the molecular mechanisms underlying its development and progression remain largely elusive. The purpose of the present study is to investigate the expression profile and functional role of microRNA-625 (miR-625) in LSCC. Materials and methods: LSCC tissues and adjacent normal tissues were collected from 86 LSCC patients. The expression levels of miR-625 and SOX4 mRNA in tissues and cells were detected by RT-qPCR analysis. The expression levels of SOX4 and EMT-related proteins were detected by western blot analysis. In vitro cell proliferation, migration, and invasion were detected by MTT assay, colony formation assay, wound healing assay, and transwell invasion assay, respectively. Dual-luciferase reporter assay was performed to verify the binding relationship between miR-625 and the 3′-UTR of SOX4. Results: The results demonstrated that miR-625 is significantly down-regulated in clinical LSCC tissues, and its low expression may be closely associated with unfavorable clinicopathological characteristics of LSCC patients. Overexpression of miR-625 significantly suppressed the proliferation, migration, invasion, and EMT of LSCC cells. Furthermore, SOX4 was validated as a direct target of miR-625 in LSCC cells, and rescue experiments suggested that restoration of SOX4 blocked the tumor suppressive role of miR-625 in LSCC cells. Conclusions: Taken together, these findings highlighted a critical role of miR-625 in the pathogenesis of LSCC, and restoration of miR-625 could be considered as a potential therapeutic strategy against this fatal disease.

The solar concentrator is an essential part of the particulate photocatalytic hydrogen production system (PPHS). In this study, a mathematical model was developed and applied to avoid non-uniform concentration of solar intensity on the receiving surface of a compound parabolic concentrator (CPC). The reflector profile curve was calculated via a first-order differential equation. The geometric concentration ratio and bottom interval parameters were changed to optimize the surface uniform concentrator (SUC). The overall performance of the concentrator was then assessed based on the optical efficiency and uniformity on the receiver in ray tracing software. A prototype of a SUC was manufactured to validate the calculation results. It is found that the conversion efficiency of solar energy to hydrogen with the SUC was 8.57% higher than that of the CPC.

The present document is based on a consensus reached by a panel of experts from Chinese Society of Allergy (CSA) and Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G). Allergen immunotherapy (AIT), has increasingly been used as a treatment for allergic rhinitis (AR) globally, as it has been shown to provide a long-term effect in improving nasal and ocular symptoms, reducing medication need, and improving quality of life. AIT is currently the only curative intervention that can potentially modify the immune system in individuals suffering from AR and prevent the development of new sensitization and the progression of disease from AR to asthma. Although the use of AIT is becoming more acceptable in China, to date no AR immunotherapy guideline from China is available for use by the international community. This document has thus been produced and covers the main aspects of AIT undertaken in China; including selection of patients for AIT, the allergen extracts available on the Chinese market, schedules and doses of allergen employed in different routes of AIT, assessment of effect and safety, patients' administration and follow-up, and management of adverse reactions. The Chinese guideline for AR immunotherapy will thus serve as a reference point by doctors, healthcare professionals and organizations involved in the AIT of AR in China. Moreover, this guideline will serve as a source of information for the international community on AIT treatment strategies employed in China.

Laryngeal cancer is a common head and neck malignant tumor. Long non-coding RNA (lncRNA) is a kind of RNA at the length more than 200 nucleotides that cannot code protein. They widely exist in the human genome. Maternally expressed gene 3 (MG3) is a kind of lncRNA that is associated with various malignant tumors development. This study explores the influence of MG3 on laryngeal cancer Hep-2 cell growth, cycle, and apoptosis related factors. Hep2 cells transfected by MG3 were treated as experimental group, while untransfected Hep2 cells were treated as control. MG3 expression was tested by real time PCR. Cell proliferation was evaluated by MTT assay. Cell cycle was determined by flow cytometry. Bcl-2, Bax, and survivin protein levels were detected by Western blot. MG3 expression significantly increased in Hep2 cells compared with control (P < 0.05). Hep2 cell OD value and cell percentage in S phase were obviously declined, while cell apoptosis were markedly enhanced (P < 0.05). OD value and cell percentage in S phase apparently reduced in 12 h, 24 h, and 48 h from experimental group (P < 0.05). Bcl-2 and survivin protein downregulated, while Bax protein elevated in experimental group following time extension (P < 0.05). MG3 overexpression inhibited laryngeal cancer Hep2 cell proliferation and arrested cell cycle with time dependence, which may achieve by suppressing Bcl-2 and survivin protein, and facilitating Bax protein expression.

To investigate the expression and clinical significance of phosphated signal transducer and activator of transcription 3 (p-STAT3) and p53 protein in laryngeal squamous cell carcinoma (LSCC), and the relationship between the two genes.Formalin-fixed and paraffin-embedded tissues, which came from 60 cases of LSCC and 32 samples of normal mucosa over 2.0 cm away from tumor margin in 32 patients with total or subtotal laryngectomy were detected for the expression of p-STAT3 and p53 protein by in SP immunohistochemistry. Micro-image analysis system was used to determine the optical density,and the result was analyzed statistically.There is over expression of p-STAT3 and p53 protein in LSCC. The expression of p-STAT3 and p53 protein in LSCC was associated with clinical stage and lymph nodal metastases (P0.05). There was a positive correlation between the expression of p-STAT3 and P53 protein. The correlation coefficient (r) was 0.6558 (P0.01).The expression of p-STAT3 and p53 protein may play an important role in the tumorigenesis,metastases and poor prognosis of LSCC. There was a positive correlation between the over expression of p-STAT3 and p53 protein in LSCC.

This study presents the results of an investigation of respiratory symptoms, lung function, chest X-ray examinations, analysis of specific IgE antibodies and skin prick tests to fungi on 130 tobacco-processing workers and 112 control workers. Industrial hygiene survey and environmental mycological studies were also performed. The average dust concentrations ranged from 13.76 to 29.55 mg/m(3) in the tobacco processing workshops. Also, the numbers of fungi colonies in the processing environments were much higher than those in the control environments. The prevalences of chronic respiratory or nasal symptoms in exposed workers were significantly higher than those in control workers (p