Search

At present, a large number of magnetic wall-climbing robots are applied to various magnetically conductive metal facades for detection and anti-corrosion work. Limited by the wall-climbing mechanism and adsorption device, most wall-climbing robots can only climb on smooth walls, and it is difficult to adapt to complex walls. Therefore, by studying the multi-media magnetic circuit conduction mechanism, a permanent magnetic adsorption wheel with a magnet array arrangement was designed in this study and applied to a hinge-type wall-climbing robot. By analyzing the influence of structural parameters on the adsorption performance and optimization design, a magnetic wheel structure with a symmetric structure that can meet a variety of adsorption requirements was obtained. To analyze the mechanical characteristics of the wall-climbing robot under complex facade conditions, we researched the adsorption performance of the designed magnetic wheel in different wall structures. Finally, the adhesion force of the magnetic wheel was verified through experimental measurements, and it was found that the hinged wall-climbing robot could adapt to different structural features and complete wall-transition and obstacle-crossing movements.

To investigate the fluorescein angiography (FA) findings and compare the extent of retinal vascularization in retinopathy of prematurity (ROP), recovered after intravitreal ranibizumab (IVR) monotherapy and those regressed spontaneously. Infants with a history of ROP who underwent FA between April 2018 and November 2021 were retrospectively included. The patients were divided into two groups based on whether they had received IVR or had ROP that regressed spontaneously without treatment. The differences between the two groups in zone Ⅱ ROP were also compared, to equalize the subgroups as much as possible in terms of disease severity. FA findings were recorded. The extent of vascularization was measured by the ratio of the distance from the center of the disk to the border of the vascularized zone (DB) and the distance from the center of the disk to the center of the fovea (DF). The width of the persistent avascular retina (PAR) was counted by disc diameters (DD). One hundred and ten eyes of 55 infants were included in the IVR group and 76 eyes of 38 babies in the untreated group. The ratio of abnormal shape of vessels was significantly higher in the IVR group than in the untreated group (50.9% v.s. 35.5%; P = 0.038), while the linear choroidal filling pattern, tortuosity of vessels over the posterior pole, dye leakage, anomalous branching of vessels, circumferential vessels, arteriovenous shunt, abnormal capillary bed, and macular abnormalities were similarly. There was a smaller temporal DB/DF ratio (4.48 v.s. 4.63; P = 0.003) and greater PAR (2.63 v.s. 1.76; P P = 0.003), while no statistical differences were observed in FA features, the DB/DF ratio, and PAR between the two subgroups. The residual vascular abnormalities and PAR may be common results of ROP regression. The DB/DF ratio of 4.0 temporally and 3.3 nasally could be used as the preliminary indicators for safe retinal vascularization in the completion of ROP regression.

Purpose The purpose of this paper is to reveal the influence of dimples on the tribological properties of the “washers-cage-rollers” system of rolling element bearing (REB) under starved lubrication. Design/methodology/approach A fiber laser marking system was used to prepare dimples patterns on the raceways of the shaft washers of cylindrical roller thrust bearings (CRTBs). The friction and wear properties of dimples textured CRTBs with different diameter of dimples (200 µm, 250 µm, 300 µm) and depth of dimples (4 µm, 8 µm, 12 µm) were researched through a vertical universal wear test rig using a customized tribo-pair under starved lubrication. The surface stresses and the influence mechanism of dimple units on the tribological behavior of REBs were also compared and discussed. Findings Although the surface stresses on the raceways of dimples textured bearings are significantly higher than that of the smooth group, the coefficients of friction and wear losses of them are all reduced under starved lubrication. When the effective volume of dimples is between 1.13 and 2.25 and the depth of dimples is smaller than 12 µm, the tribological properties of dimples textured CRTBs are significantly improved. In this work, when the diameter of dimples is 250 µm, and the depth of dimples is 8 µm, the textured bearings can provide the excellent friction-reduction ability and outstanding wear resistance. Originality/value This work is a valuable reference for the raceway design and optimization of REBs.

The paper presents a wall-climbing robot featuring self-compliance for variable curvature facades. The high payload and maneuverability make it highly potential in heavy-duty operation of industrial applications. The robot consists of two traction modules and one link module. Each traction module is equipped with magnetic adhesion and crawler traction submodules. The two traction modules are connected by the link module with 4 degrees of freedom (DoF) of passive compliance. Variable curvature facade self-compliance is achieved by the passive compliant link module, which results in the attitude change decoupling of the two traction modules. The attitude can be adjusted under the effect of magnetic adhesion force to comply with the curvature variations. High payloads are achieved by the large contact area between the crawler and the surface. Omni-directional high maneuverability is enabled by the speed difference between the motors of two traction modules. The robot can maneuver in any direction on the surface with a minimum radius of 1 m and carry 36 kg payload on vertical surfaces.

We reported a facile metal-free conversion of aryl halides to the corresponding boronic esters catalysed by an in situ formed donor–acceptor complex. A two-step one-pot method was also developed for site selective aromatic C–H bond borylation.

In this research, we propose a novel wheel-legged mobile robot to address the problems of insufficient obstacle-crossing performance and poor motion flexibility of mobile robots in non-structural environments. Firstly, we designed the transformable wheel mechanism and tail adaptive mechanism. Secondly, the kinematic model of the robot is established and solved by analyzing the whole motion and wheel-legged switching motion for the operation requirements under different road conditions. By synthesizing the constraint relationships among the modules and analyzing the robot’s obstacle-crossing abilities, we systematically established the mechanical model of the robot when it encounters obstacles. Thirdly, we studied the stability of the robot based on the stable cone method in the case of slope and unilateral transformation wheel deployment and achieved the tipping condition in the critical state. Finally, we used ADAMS software to simulate and analyze the driving process of the robot in various types of terrain and obstacles in order to verify that it has superior performance through obstacles and motion flexibility. The analysis shows that the robot can passively adapt to various complex and variable obstacle-filled terrains with obstacle heights which are much higher than its center of gravity range. The results of the study can provide a reference for the structural optimization and the obstacle-crossing performance improvement of mobile robots.

AIM: To investigate therapeutic effects of traditional Chinese medicine formulations, Hexuemingmu (HXMM) on laser-induced choroidal neovascularization (CNV) and follow-up effect in mice. METHODS: C57BL/6 mice of 8-week-old were used and CNV was induced with 577 nm laser photocoagulation. Animals were randomly divided into groups and different doses of HXMM were administered daily. One, four, and eight weeks after the intervention, the electroretinogram (ERG), fundus fluorescence angiography, choroidal flat mount and immunofluorescence staining were preformed to evaluate the function and CNV formation. The expression levels of angiogenic proteins were determined by Western blotting and immunofluorescence staining. An analysis of variance and Kruskal-Wallis test were used to test the differences among the groups. RESULTS: The results showed that HXMM effectively increased amplitude of ERG of mice (P

After angiogenesis-activated embryonic and early postnatal vascularization, endothelial cells (ECs) in most tissues enter a quiescent state necessary for proper tissue perfusion and EC functions. Notch signaling is essential for maintaining EC quiescence, but the mechanisms of action remain elusive. Here, we show that microRNA-218 (miR-218) is a downstream effector of Notch in quiescent ECs. Notch activation upregulated, while Notch blockade downregulated, miR-218 and its host gene Slit2, likely via transactivation of the Slit2 promoter. Overexpressing miR-218 in human umbilical vein ECs (HUVECs) significantly repressed cell proliferation and sprouting in vitro. Transcriptomics showed that miR-218 overexpression attenuated the MYC proto-oncogene, bHLH transcription factor (MYC, also known as c-myc) signature. MYC overexpression rescued miR-218-mediated proliferation and sprouting defects in HUVECs. MYC was repressed by miR-218 via multiple mechanisms, including reduction of MYC mRNA, repression of MYC translation by targeting heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), and promoting MYC degradation by targeting EYA3. Inhibition of miR-218 partially reversed Notch-induced repression of HUVEC proliferation and sprouting. In vivo, intravitreal injection of miR-218 reduced retinal EC proliferation accompanied by MYC repression, attenuated pathological choroidal neovascularization, and rescued retinal EC hyper-sprouting induced by Notch blockade. In summary, miR-218 mediates the effect of Notch activation of EC quiescence via MYC and is a potential treatment for angiogenesis-related diseases., Graphical abstract, Endothelial cell (EC) quiescence is important for vessel homeostasis and function, but the mechanism remains elusive. Han and colleagues report that miR-218 mediates the effect of Notch activation on promoting EC quiescence via repressing MYC, which holds potential in the treatment of angiogenesis-related diseases.

Purpose: Armed with the theory of embodied cognition proposing tight interactions between perception, motor, and cognition, this study aimed to test the hypothesis that speech rate–altered Mandarin lexical tone perception in quiet and noisy environments could be affected by the bodily dynamic cross-modal information. Method: Fifty-three adult listeners completed a Mandarin tone perception task with 720 tone stimuli in auditory-only (AO), auditory–facial (AF), and auditory-facial-plus-gestural (AFG) modalities, at fast, normal, and slow speech rates under quiet and noisy conditions. In AF and AFG modalities, both congruent and incongruent audiovisual information were designed and presented. Generalized linear mixed-effects models were constructed to analyze the accuracy of tone perception across different conditions. Results: In Mandarin tone perception, the magnitude of enhancement of AF and AFG cues across three speech rates was significantly higher than that of the AO cue in the adverse context of noise, yet additional metaphoric gestures did not show significant differences from the facial information. Furthermore, the performance of auditory tone perception at the fast speech rate was significantly better than that at the normal speech rate when the inputs were incongruent between auditory and visual channels in quiet. Conclusions: This study provided compelling evidence showing that integrated audiovisual information plays a vital role not only in improving lexical tone perception in noise but also in modulating the effects of speech rate on Mandarin tone perception in quiet for native listeners. Our findings, supporting the theory of embodied cognition, are implicational for speech and hearing rehabilitation among both young and old clinical populations.

To investigate the influence of age on the function and morphology of patients with myopic choroidal neovascularization (mCNV) and to evaluate the effect and prognostic factors of recurrence of Conbercept treatment on mCNV patients over 50 years. A total of 64 patients (64 eyes) with mCNV were enrolled in this retrospective study. The differences in baseline best-corrected visual acuity (BCVA) and morphological features on imaging between the younger group (˂ 50 years) and the older group (≥ 50 years) were analyzed. Of all, 21 eyes of 21 mCNV patients aged over 50 years who received Conbercept injection were further analyzed. Between the younger and the older group, significant differences were shown in mean BCVA (0.58 ± 0.28 vs 0.77 ± 0.31), subfoveal choroidal thickness (SFCT) (108.17 ± 78.32 μm vs 54.68 ± 39.03 μm) and frequency of vitreoretinal interface abnormalities (VIA) (2 vs 13), respectively (P

Rope-driven robots are increasingly being applied for the efficiently cleaning of glass curtain walls. However, increasingly complex wall surfaces and the various shapes of obstacles may block the robot and reduce coverage. In this study, three-DOF rope-driven cleaning robots and a full-coverage path-planning algorithm were developed to achieve global operation. The robot adopts a five-rope parallel configuration, and four winches are mounted on the wall and one on the ground to produce 3D motion performance. We used a grid method to build the wall model to mark obstacles, and then we decomposed it according to the wall curvature to better access cleaning subareas. To further increase the cleaning coverage rate, a full-coverage path-planning algorithm based on an improved priority heuristic was designed, which does not ignore the inset area of U-shaped obstacles. By introducing two sets of priority criteria to judge the forward direction, the robot can switch directions to cover a whole area when encountering U-shaped obstacles. Furthermore, by planning a return route requiring the least amount of time when entering a dead zone, an escape strategy was developed to prevent the robot from being unable to choose a direction. The experimental results show that the robot, after applying the proposed path-planning algorithm, could complete the global cleaning of complex glass walls with various obstacles.

This paper proposes a novel wheel−leg hybrid robot that can be applied on both flat and rugged terrains, it utilizes two passive transformable symmetrical wheels that combine the stability of the circular wheel and the obstacle climbing ability of the legged wheel. To minimize the number of actuators, the transformation process of the wheel is designed to be triggered passively when in contact with the obstacles. A new triggering mechanism is employed to eliminate the adverse effect of the robot’s weight on the transformation torque. The parameters of the wheel are optimized to maximize the climbing ability in low-friction conditions. The robot’s body length and angular velocity are also tuned based on the dynamic model during the obstacle climbing process. The simulation experiment results show that the robot can switch modes stably on terrain with a friction coefficient as low as 0.2, and can climb over an obstacle 3.9 times as tall as its wheel radius.

The positioning accuracy of a robot directly affects the quality of its operations. In this study, a calibration method is proposed based on combining a model with least-squares support vector regression (LSSVR) to improve robot positioning accuracy. First, a geometric error model of the robot is established. Second, singular value decomposition (SVD) and physical model analysis method are employed to process the coupling parameters in the error model to improve the accuracy and efficiency of identification. Third, as nongeometric errors hinder the construction of an accurate and complete mathematical model and affect the residual positioning errors of the robot, LSSVR is used to compensate for the residual positioning errors caused by nongeometric errors. The proposed method thus improves the accuracy and robustness of finite sample estimation. Finally, an experiment is performed on an IRB1410 robot with a parallelogram mechanism. The maximum/mean positioning errors of the robot decrease from 2.0348/1.0978 mm to 0.1659/0.0733 mm, and the effectiveness of the proposed method is verified. The proposed method has higher prediction accuracy and stability for small samples than other methods.

This study presents the influence of initial deflection angle (IDA) on the tribological properties of gray cast iron (GCI) rings with curve distributed pits in the radial direction (CDPRD). The thermal behavior of pits textured GCI rings with different initial deflection angles (0°, 30°, 45°, 60°, 75°) and fixed deflexional angle of adjacent pits (DAAP, 10°) were researched, through APDL programming. A pin-on-disc wear test rig was used to reveal the anti-wear performance of samples under dry sliding, at a rotating speed of 200 rpm, with a normal load of 70 N. An electronic balance and an optical microscope (OM) were used to obtain their wear losses and worn surfaces, respectively. The results show that: comparing with the smooth GCI ring, there are evident high temperature regions between two adjacent pits groups, called “temperature barrier and separation effect”. Among all textured samples, the von Mise’s stress of IDA45 is the most stable, and its temperature is almost the lowest. The friction coefficient curve and the wear loss of IDA45 are also the lowest, and much lower than the loss of smooth GCI ring, indicating the excellent anti-wear performance. This work can provide a valuable reference for the surface design of journal bearings.

At present, corneal transplantation has become the main surgical method for infectious keratitis. However, the rejection of corneal graft after operation leads to graft opacity, which is an important reason for the failure of transplantation. There is no unified conclusion whether the rejection can be reduced by matching human leucocyte antigen (HLA) before operation. The purpose of this meta-analysis is to explore the correlation between HLA locus matching and corneal transplantation rejection, so as to provide evidence-based medical evidence for clinical corneal transplantation in the treatment of infectious keratitis.Search English databases, such as PubMed, Medline, Embase and Evidence-based Medicine Library by computer; Chinese databases, such as China Biomedical Literature Database, China Knowledge Network (CNKI) database, Wanfang database, Weipu database, and Google Academic database. According to Cochrane Handbook 5.0 risk assessment table, two researchers made random sequence random allocation method, blind method, allocation scheme hiding, integrity of data results and quality score of research results. The bias risk evaluation of Rev Man 5.3 software was used to evaluate the risk bias of the references.A total of 5 literatures were included, and 725 eyes underwent penetrating keratoplasty, all of which were randomized controlled trials (RCTs). The quality of the included articles was medium to high quality. A meta-analysis of four HLA-A matching articles showed odds ratio (OR) =0.28, 95% confidential interval (CI): (0.15, 0.51), significance test Z=4.08, P0.0001, and the difference was statistically significant. Meta-analysis was performed on four HLA-B matching articles and showed OR =0.50, 95% CI: (0.27, 0.89), significance test Z=2.33, P=0.02, and the difference was statistically significant. Meta-analysis of four HLA-DR matching articles showed OR =0.69, 95% CI: (0.41, 1.17), significance test Z=1.39, P=0.17, and the difference was not statistically significant.In patients with infectious keratitis undergoing corneal transplantation, preoperative matching of HLA-A, HLA-B, and HLA-DR sites played an important role in corneal transplantation. Preoperative HLA matching is of clinical significance.

Organoboron compounds are very important building blocks which can be applied in medicinal, biological and industrial fields. However, direct borylation in a metal free manner has been very rarely reported. Herein, we described the successful direct borylation of haloarenes under mild, operationally simple, catalyst-free conditions, promoted by irradiation with visible light. Mechanistic experiments and computational investigations indicate the formation of an excited donor-acceptor complex with a -3.12 V reduction potential, which is a highly active reductant and can facilitate single-electron-transfer (SET) with aryl halides to produce aryl radical intermediates. A two-step one-pot method was developed for site selective aromatic C-H bond borylation. The protocol's good functional group tolerance enables the functionalization of a variety of biologically relevant compounds, representing a new application of aryl radicals merged with photochemistry.

In recent years, many wall-climbing robots have been developed in the field of petrochemical storage tank maintenance. However, it is difficult for most of them to be widely used due to common problems such as poor adsorption capacity, poor adaptation to elevation, and low trajectory tracking accuracy. In order to solve the problem of the robot not being able to achieve high-precision operation on curved surfaces, a new wall-climbing robot system is designed. Based on the magnetic wheel adsorption method, a passive adaptive motion mechanism that can adapt to walls with different curvatures is proposed. In order to improve the trajectory tracking accuracy of the wall-climbing robot, the kinematic model of the wall-climbing robot is simplified, a velocity compensation controller is designed, and the stability of the controller is proved by introducing the Lyapunov equation. Through experiments, the controller designed in this paper is compared with the conventional controller to verify the effectiveness and superiority of the controller. The experimental results show that the robot can move safely and stably on curved surfaces, with improved tracking accuracy and reduced trajectory deviation caused by response time lag, and meets the maintenance operation requirements of wall-climbing robots.

Sugar beet is an important economic crop because of its high sucrose concentration in the roots. However, information on the relationship between sucrose metabolism-related enzymes and root yield is scarce. In this study, we aimed to investigate the activity of sucrose phosphate synthase (SPS), sucrose synthase (SS), and invertase (INV), which are key enzymes in sucrose metabolism, in relation to root weight and sucrose content in different parts of the sugar beet plant over the growth cycle. Results showed that root SPS, SS, and INV activities positively correlated with sucrose content. SPS activity increased with maturity, reaching the highest rates at harvest, whereas INV activity was high at the early stages and gradually decreased with maturity. No association was found between SPS, SS, or INV activity in the leaves and petioles with sucrose content, or between root weight and sucrose content. Overall, our results provide new insights into the underlying mechanism of sucrose metabolism and will allow faster development of sugar beet cultivars with high sucrose content.

Background: Immune checkpoint blockers (ICBs) are increasingly being used to treat patients with advanced hepatocellular carcinoma (HCC), but only a third of these patients are sensitive to ICBs. Emerging evidence suggests that ferroptosis could be a novel target for antitumor treatment, and combined treatment with ferroptosis inducers might enhance sensitivity to immunotherapy. However, there is a lack of information on the crosstalk between ferroptosis-related lncRNAs and anti-tumor immunity. Therefore, we aim to explore prognostic value of ferroptosis-related lncRNAs and clarify potential role in ICBs of HCC.Methods: We obtained mRNA and lncRNA expression data from two independent cohorts (TCGA and GEO database). Univariate Cox, the least absolute shrinkage and selection operator (Lasso) algorithm and multivariate Cox analysis were used to construct a lncRNA signature, which was evaluated using the area under the receiver operating characteristic curve (AUC) and Kaplan–Meier curves. Tumor-infiltrating cell (TIC) profiling and the tumor immune dysfunction and exclusion (TIDE) algorithm were used to validate the signature model and immunotherapy. Finally, we adopted RT-PCR assay to evaluate the differential expression of lncRNAs in HCC tissues in our hospital.Results: The ferroptosis-related lncRNA signature included five lncRNAs, most of which were positively correlated with clinical stage and grade. The signature could stratify patients into two risk groups, with the high-risk group associated with a shorter overall survival (OS, p < 0.05) in TCGA-LIHC and GSE76427. Besides, the AUCs of the 1-, 3-, and 5-years OS were 0.772, 0.707, and 0.666, respectively. Gene set enrichment analysis (GESA) of lncRNAs revealed enrichment of oncogenic and immune-related pathways. The TIC profiling indicated a close correlation between the signature and immune cells. Furthermore, the high-risk group had a better response to immunotherapy than low-risk group. RT-PCR demonstrated these five lncRNAs were upregulated in cancerous tissue than normal tissues.Conclusions: The ferroptosis-related lncRNA signature could accurately predict the OS of HCC patients and may serve as an independent clinical factor for patients’ outcomes. Ferroptosis-related lncRNAs may remodel the tumor microenvironment (TME) and affect the anti-cancer ability of ICBs, and therefore, could potentially act as an indicator for the response to immunotherapy in HCC.

Purpose: The aim of this study is to explore the clinical features of spontaneous regression of retinopathy of prematurity (ROP) in China, including fundus appearance, time course, and affecting factors.Methods: Data of pediatric patients in whom ROP spontaneously regressed without treatment were collected, including general demographics, medical history, zones and stages of ROP, and changes of fundus appearance. The fundus manifestations of spontaneous regression in ROP were systematically summarized. Meanwhile, the time course of spontaneous regression in ROP was further analyzed, including the onset time, completion time, and duration of regression, which were all compared across different ROP zones and stages. The associated factors were analyzed by survival analysis for their correlation with delayed regression for the first time.Results: Two hundred thirty-seven eyes of 237 pediatric patients were included. The fundus manifestations of regression differed across stages. Lesions gradually subsided, and the retinal vessels gradually vascularized completely. However, despite ROP regression, some abnormalities remained. We observed avascular retina in the temporal periphery (19.0%), increased vascular branching (6.8%), retinal pigmentary changes (6.8%), and smaller angle between the upper and lower temporal retinal vessel trunks (3.0%). Acute ROP started to regress at a median 40 weeks of postmenstrual age (PMA) and completely regressed by median 49.0 weeks of PMA. The median duration for regression was 8.5 weeks. The zone II ROP and stage 3 ROP had a later time for onset and completion of regression, and longer duration. Anemia and retinal hemorrhage (RH) were identified as independent risk factors for delayed regression by survival analysis.Conclusions: During spontaneous regression, the fundus appearance is diverse, and the retinal vessels gradually vascularized completely. The time course of regression differs depending on the ROP zone and stage. Anemia and RH are independent risk factors for delayed regression. Further research of the natural course of the regression of ROP is needed to help design effective screening and follow-up plans.

Based on the data support, it is an effective way for the college to strengthen the connotation construction and constantly improve the quality of education and teaching by building a perfect quality assurance system in college and forming a long-term mechanism to continuously improve the quality of education. Taking the practice of Shenyang Institute of technology as an example, this paper systematically expounds the specific methods and implementation effectiveness of the college to make full use of the relevant data of teaching quality, scientifically analyze and diagnose problems, construct and improve the quality assurance system of education and teaching, and form the operation mechanism of “closed-loop control and continuous improvement”. This will also lay a foundation for the college to carry out big data research on education quality in the future.

To reveal the influence of pit units on the friction and wear performance of multi-rollers-sliding-rolling tribo-pairs (MRSRTs), the tribological behavior of pits textured MRSRTs with 18 rollers under periodic varied load and dry wear were researched. The texture parameters include: diameter of pits (DAOP, 200, 250, and 300 μm), depth of pits (DPOP, 10, 20, and 30 μm). The wear losses and worn surfaces of samples were obtained. The influence mechanism of pits on the tribological performance of MRSRT was also discussed. The results show that: The average coefficients of friction (COFs) of pits textured MRSRTs are all lower than that of smooth one under periodic varied load and dry wear. Their mass losses are almost all higher than that of smooth MRSRT. The influence of DPOP on the tribological properties of textured MRSRTs is significant and continuous compared with that of DAOP. The depth-diameter ratio is an important factor for the wear losses. In this work, when the DAOP is 200 μm and the DPOP is 30 μm, that is, the depth-diameter ratio is 0.15, compared with the smooth sample, the mass loss of MRSRT is reduced by about 13%, and its average COF is reduced by 30.5%. This work can provide a valuable reference for the surface design and optimization of rolling element bearings.

Recently, numerous wall-climbing robots have been developed for petrochemical tank maintenance. However, most of them are difficult to be widely applied due to common problems such as poor adsorption capacity, low facade adaptability, and low detection accuracy. In order to realize automatic precise detection, an innovative wall-climbing robot system was designed. Based on magnetic circuit optimization, a passive adaptive moving mechanism that can adapt to the walls of different curvatures was proposed. In order to improve detection accuracy and efficiency, a flexible detection mechanism combining with a hooke hinge that can realize passive vertical alignment was designed to meet the detection requirements. Through the analysis of mechanical models under different working conditions, a hierarchical control system was established to complete the wall thickness and film thickness detection. The results showed that the robot could move safely and stably on the facade, as well as complete automatic precise detection.

Nafion membrane with macropores is synthesized from silica crystal and composited with Pt nanoparticles to fabricate macroporous ionic polymer-metal composite (M-IPMC) actuator. M-IPMC shows highly dispersed small Pt nanoparticles on the porous walls of Nafion membrane. After the electromechanical performance test, M-IPMC actuator demonstrates a maximum displacement output of 19.8 mm and a maximum blocking force of 8.1 mN, far better than that of IPMC actuator without macroporous structure (9.6 mm and 2.8 mN) at low voltages (5.8–7.0 V). The good electromechanical performance can be attributed to interconnected macropores that can improve the charge transport during the actuation process and can allow the Pt nanoparticles to firmly adsorb, leading to a good electromechanical property.

Weld detection is vital to the quality of ship construction and navigation safety, and numerous detection robots have been developed and widely applied. Focusing on the current bottleneck of robot safety, efficiency, and intelligent detection, this paper developed a wall-climbing robot that integrates multiple sensors and uses fluorescent magnetic powder for nondestructive testing. We designed a moving mechanism that can safely move on a curved surface and a serial-parallel hybrid flexible detection mechanism that incorporates a force sensor to solve the robot&rsquo, s safe adsorption and a flexible detection of the curved surface to complete the flaw detection operation. We optimized the system structure and improved the overall performance of the robot by establishing a unified mechanical model for different operating conditions. Based on the collected sensor information, a multi-degree of freedom component collaborative flexible detection method with a standard detecting process was developed to complete efficient, high-quality detection. Results showed that the developed wall-climbing robot can move safely and steadily on the complex facade and can complete the flaw detection of wall welds.

Regular detecting film thickness and morphology deformation of nuclear fuel assembly (NFA) is an essential measure to ensure safe operation of nuclear reactors. This paper presents an error compensation and flexible measurement method for an NFA detection device to realize safe, accurate and efficient measurement of film thickness and morphology deformation. The detection device combining adaptive aligning mechanism, flexible measuring mechanism, and serial-parallel hybrid measuring mechanism is designed for accurate contact measurement of complex deformed NFA. By probabilistically adjusting compensation parameters of the closed-loop measurement loop constructed by serial-parallel hybrid measuring mechanism, a comprehensive error compensation method is proposed to further improve measurement accuracy. Through dynamically monitoring the contact measuring forces calculated by mechanical model without additional sensors, a flexible measurement method is proposed to ensure safe detection of high-risk NFA. Experimental results indicate that the device after applying the proposed methods can complete accurate and flexible measurement of NFA. The maximum measurement errors of film thickness and morphology deformation are reduced to 3.5 μm and 8.3 μm respectively, and the maximum measuring forces are controlled within 4.37 N.

In order to reduce the radiation dose of operators and the labor intensity of staff during the nuclear reactor operation, a remote operation nuclear multifunction robot was designed by service for salvage operation in the nuclear reactor pool. The purpose of this paper is making the robot to be a remote control tool to help staff in the nuclear reactor pool. Firstly, the kinematics analysis of the robot's six-wheeled mobile platform and four-degree-of-freedom manipulator are carried out. Then, based on the whole results of kinematics analysis, the overall mechanical structure of the robot is designed radiation-resistant and compact.

Choroidal neovascularization (CNV) is an acknowledged pathogenic mechanism of various ocular diseases, and in situ cells and mobilized bone marrow-derived cells (BMCs) are thought to participate in this process. We aimed to evaluate the roles of integrin α5 in BMCs and vascular endothelial cells (VECs) in the CNV process mediated by SDF-1/CXCR4 signaling. Adult wild-type mice were engrafted with whole BMCs obtained from GFP transgenic mice and then laser injured to induce CNV. BMCs and RF/6A cells were cultured to discover the mechanism of CNV in vitro. BMCs were mobilized to CNV areas, which expressed elevated SDF-1 and CXCR4. When SDF-1 was intravitreally injected, the number of BMCs was profoundly increased. In the SDF-1-treated group, the levels of integrin α5 expressed on BMCs and VECs were significantly higher than those on the cells in the control group. SDF-1 significantly increased the expression and positive ratio of integrin α5, which was involved in the recruitment and differentiation of BMCs into BMC-derived VECs, and these effects were suppressed by the CXCR4 inhibitor AMD3100. The PI3K/AKT pathway rather than the ERK pathway mediated SDF-1/CXCR4 induction of integrin α5. Integrin α5 suppression efficiently prevented the production of TGF-β and bFGF but not VEGF. Inhibiting the SDF-1/CXCR4-PI3K/AKT-integrin α5 axis reduced CNV severity. Integrin α5 participates in BMC recruitment and differentiation in SDF-1/CXCR4-induced CNV and inhibition of this pathway may be a new approach to inhibit CNV.

A reactor robot for object salvaging underwater was designed to reduce the labor intensity of operators under the nuclear radiation environment. The control system of the robot, composed of control system hardware and control system software, was designed to be compact and radiation resistant. The control algorithm of the robot based on current, velocity, and position feedback of each motor makes the robot achieve the goal of salvaging exactly and rapidly. In order to verify the stability of the control system, the salvaging foreign matter experiment was tested in nuclear base. The result shows that the control system of the robot is stable enough.

Background: Oxidative stress (OS) is an essential factor in the pathogenesis of branch retinal vein occlusion (BRVO). Lines of studies have demonstrated the role of hydrogen gas in the regulation of OS. This study was designed to evaluate the effect of hydrogen gas on BRVO rat model which was established by modified laser photocoagulation method. Methods: 24 BRVO rats were randomly divided into two groups: hydrogen gas (H) group (42% H2, 21% O2, 37% N2) and model (M) group (21% O2, 79% N2). Rats in H group were inhaled with hydrogen gas for 8 hours every day continued to 30 d post-occlusion. 12 age-matched healthy rats were served as control (C) group. Retinal function and morphology were detected at 1, 7, 14 and 30 d post-occlusion. Furthermore, the expression of vascular endothelial growth factor (VEGF-α) was detected by immunofluorescent staining. Results: Full-field Electroretinography (FfERG) revealed that the amplitude of the d3.0 (dark-adaptation 3.0 response) b wave and OPs2 (oscillatory potentials) wave achieved quick recovery at 7 d post-occlusion in H group compared with M group (p<0.05; pppppp>0.05). Conclusions: Our findings demonstrate that inhalation of hydrogen gas could alleviate retina edema, shorten reopen time and improve retinal function via decreasing VEGF-α expression. Key words: Hydrogen gas; branch retinal vein occlusion; electroretinography; vascular endothelial growth factor

Specialty is the basic teaching in colleges and universities to highlight the characteristics of education, improve the quality of teaching, optimize the structure of specialty, and enhance the level of the University. Using the visualization tool of knowledge map, we found that: the core network of specialty research in China has not yet formed. At present, the research mainly focuses on the connotation development of specialty construction, the integration of industry and education, the construction of vocational education curriculum and the construction of characteristic specialtys, showing the research characteristics of “three stages and two directions”. We should further encourage undergraduate colleges and universities to attach importance to the theoretical research of specialty construction, promote the research of characteristic specialtys construction under the collaborative background, and better play the leading edge and diversification of scientific research knowledge.

Background Severe retinopathy of prematurity (ROP) with extremely unfavorable prognosis among infants can do great damage to individuals and bring tremendous social-economic burden. The purpose of this study is to describe the demographic and ocular characteristics of infants who presented with stage 5 ROP in order to identify reasons why they have become blind, and to identify contributing factors in order to focus great attention on the current ROP program and to inspire more effort in ROP screening in middle income countries. Methods A retrospective review of consecutive infants with stage 5 ROP from December 2010 to December 2016 in Department of Ophthalmology, Xijing Hospital. Various parameters retrieved included birthweight, gestational age, age at initial examination, postmenstrual age, screening details, check-up details and reasons for consultation. Ocular findings were recorded and also detected by ultrasonography. Results A retrospective review of 20 consecutive infants with stage 5 ROP are included. Mean birthweight was1712.3 ± 512.97 g and mean gestational age at birth was 32.1 ± 2.21 weeks. Median age at first consultancy was 9.7 month. Median postmenstrual age first consultancy was 52 weeks. All infants were never screened for ROP before they came to the referral center. Of twenty stage 5 ROP infants, 13 cases presented with bilateral stage 5 features. Of the 40 eyes of 20 infants, 33 eyes were diagnosed as stage 5. Leukocoric pupil, closed funnel configuration of retinal detachment (RD), posterior synechia, extraretinal fibrovascular proliferation and retinal folds were the most significant indicators of bad prognosis. Ten eyes appeared no fixation to light, while 30 eyes exhibited following to light or following to toys. Conclusions Our study shows that in relatively less-developed regions of China, more needs to be done to spread awareness about the disease among pediatricians, neonatologists and ophthalmologists as well as parents of premature infants. Thus, a comprehensive control system which is a whole network of propaganda, screening, treatment and follow-up are encouraged especially in less developed areas in China as well as worldwide.

Our previous investigations have shown that bone marrow-derived cells (BMCs), including mesenchymal stem cells (MSCs), contribute to the development of choroidal neovascularization (CNV) as sources of cells and angiogenic factors. Two main steps for circulating BMCs to integrate into CNV lesions are extracellular matrix remodeling and consequential cell migration. MicroRNAs (miRNAs) were found to be involved in CNV development; however, little is known about whether miRNAs regulate the contribution of BMCs to CNV. In the present study, we found that the expression of miR-188-5p was decreased in cultured hypoxic MSCs and BMCs within laser-induced CNV in mice. Matrix metalloproteinase 2 (MMP-2) and MMP-13 were both discovered as targets of miR-188-5p by bioinformatics predictions and dual-luciferase reporter system. Accordingly, increased expression of MMP-2/13 was found in hypoxic MSCs and BMCs in CNV lesions. Furthermore, miR-188-5p mimic transfection caused downregulation of MMP-2/13 in hypoxic MSCs and decreased tube formation of co-cultured vascular endothelial cells. Intravitreal injections of a miR-188-5p agomir attenuated the severity of CNV and inhibited the migration of BMCs into CNV lesions in mice. Our study suggests that miR-188-5p regulates the contribution of BMCs to CNV development by targeting MMP-2/13-mediated extracellular matrix degeneration, and miR-188-5p serves as a therapeutic target to treat CNV-related diseases.

Ocular neovascularization is a comprehensive process involved in retinal vascular development and several blinding diseases such as age-related macular degeneration and retinopathy of prematurity, with vascular endothelial growth factor (VEGF) regarded as the master regulator. However, the qualified effect of anti-VEGF therapy reveals that the underlying mechanisms are still not clearly identified. To initialize angiogenesis, endothelial cells undergo a phenotype switching to generate highly migratory and invasive cells. This process shares certain similar characters observed in endothelial-mesenchymal transition (EndMT). Here, we found that SNAI1, an EndMT transcription factor, was expressed by endothelial cells in both physiological and pathological ocular neovascularization. SNAI1 overexpression triggered cell morphological change and enhanced cell motility, while loss of SNAI1 attenuated migration, invasion and sprouting. RNA sequence analysis further revealed that SNAI1 knockdown decreased the expression of genes related to cytoskeleton rearrangement and ECM remodeling. Moreover, intravitreal injection of small interfering RNA of SNAI1 suppressed new vessel formation in developing retina as well as mice model of choroidal neovascularization and oxygen-induced retinopathy. Therefore, we propose that the EndMT transcription factor SNAI1 promotes the early phase of ocular neovascularization and may provide a potential therapeutic target.

Captopril-polyethyleneimine (CP) containing low molecular weight polyethyleneimine and anti-angiogenesis drug captopril conjugated via an amide bond was fabricated to modify gold nanoparticles and complex with siRNA to construct siRNA/CP/GNP complexes for the co-delivery of drug and siRNA in anti-angiogenesis breast cancer therapy. The self-assembled siRNA/CP/GNP complexes exhibited desirable and homogenous particle size, reasonable positive charges and condensation ability, and effective gene-silencing property in vitro. In addition, siRNA/CP/GNP complexes co-delivering captopril and siRNA achieved combined angiogenesis suppression by more effectively downregulating the expression of vascular endothelial growth factor mRNA and protein via different pathways in vitro, as compared to mono-delivery systems. In vivo investigation on nude mice bearing MDA-MB435 tumor xenografts revealed that siRNA/CP/GNP complexes possessed satisfying tumor homing ability and strong antitumor activity. These findings suggested that siRNA/CP/GNP complexes could be an ideal system for simultaneous transfer of drug and siRNA, which might be a new promising strategy for effective breast cancer therapy.

Corn-like, γ-Fe2O3@SiO2@TiO2 core/shell heterostructures were synthesized by a modified solvothermal reduction combined with a sol-gel method. SiO2 shells were first deposited on monodisperse Fe3O4 microspheres by a sol-gel method. Fe3O4@SiO2@TiO2 corn-like heterostructures were then obtained by sequential TiO2 coating, during which the magnetic dipolar interactions induced the anisotropic self-assembly process. After annealing at 350 °C, the crystalized TiO2 enhanced photocatalytic activity, while Fe3O4 was converted to γ-Fe2O3. The corn-like γ-Fe2O3@SiO2@TiO2 photocatalyst can be recycled and reused by magnet extraction. Despite the photocatalytic activity decreased with each cycle, it can be completely recovered by moderate heating at 200 °C.

© Copyright 2017 Shaoni Sun et al. To investigate the influence of surface features, in the form of pits, on the wear resistance of grey cast iron (GCI), a finite element model of the pin-on-disc friction system, with pits distributed in a curved radial d irection, was developed using APDL programming and the tribological behavior of textured surfaces was studied. The influence of relative rotation direction between the disc and the pin on the thermal behavior of the friction system under dry wear conditions was researched. GCI and C30E steel samples with pit textured surfaces were manufactured using laser marking equipment and tested using a tribology wear testing rig. The mass losses were measured and the worn surfaces were characterized. The influence of different rotation directions on the tribological behavior of the pit textured surfaces was also investigated. The simulation and test results revealed that rotation direction was a crucial parameter in determining the tribological behavior of surfaces with these features, regardless of the material. Under the conditions tested, when the pin rotated anticlockwise, the samples showed better friction and wear behavior than when the pin rotated clockwise. These results can provide important guidance for the optimization of the design of heavy-load brake systems and other similar applications.

Background and objective Recent studies indicated that non-small cell lung cancer (NSCLC) patients with mutant K-ras were resistant to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). The aim of this study is to explore the relationship between the mutation of K-ras gene and NSCLC in Guangxi by detecting the point mutations in codon 12, 13 and 61 of K-ras gene in NSCLC. Methods The point mutations in codon 12, 13 and 61 of K-ras gene were detected by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) products and DNA sequencing analysis in 105 cases of NSCLC tissues and 30 cases of adjacent normal tissues. Results No point mutation in codon 12, 13 and 61 of K-ras gene was found in 105 cases of NSCLC tissues and 30 cases of adjacent normal tissues. In this study, the mutation frequency of K-ras gene in NSCLC was 0 (0/105). Conclusion The high proportion of K-ras gene in wild-type indicates that patients with NSCLC in Guangxi could take more benefits from the therapy with EGFR-TKIs.

Incomplete perifoveal posterior vitreous detachment (PVD) associated with abnormal vitreomacular adhesion (VMA) can cause vitreomacular traction (VMT) and macular hole (MH) formation, which require vitrectomy treatment. Pharmacologic vitreolysis, which is intravitreal injection with vitreolytic enzymes to resolve VMA, may be used as an alternative therapy.Ocriplasmin, formerly known as microplasmin, is a recombinant truncated form of plasmin with proteolytic activity against fibronectin and laminin.It was recently approved for VMA treatment in the European Union and USA. Phase III studies indicated that ocriplasmin injection was a safe and effective treatment for selected cases of symptomatic VMA and MH. VMA release was achieved in 26.5% of ocriplasmin-injected eyes versus 10.1% of the placebo group. MH closure was achieved in 40.6% as compared with 10.6% of the placebo group.In comparison with the outcome after vitrectomy, the success rate of ocriplasmin was still far below expectation. Ocular adverse events included vitreous floaters, photopsia and profound visual decline. Its efficacy and safety need to be further evaluated in more clinical trials.

This paper presents a lower limb rehabilitation robot based on free gait and virtual reality, which is intended to improve therapeutic efficacy. With the help of the robot, patients with motor disabilities can walk with free gait in a virtual environment and choose between passive and active training modes. So the impaired limbs can get appropriate exercise in all clinical stages and the motivation to participate in rehabilitation training is increased. Inspired by this idea, a new free gait generation algorithm is proposed and the working mechanism of the passive/active training mode is explained in detail. And the results of preliminary experiments are presented to demonstrate the effectiveness of the proposed algorithm and the performance of the rehabilitation system.

To survey popularity and clinical characteristics of retinopathy of prematurity (ROP) in Xi'an area in infants with birth weight over 2 000 g.Retrospective case-series study. ROP screening data of 1 866 infants was collected and reviewed from Department of Ophthalmology, Xijing Hospital from January 2008 to December 2012.One thousand eight hundreds and sixty-six cases (3 732 eyes) with 1 166 males and 700 females were examined. Their gestation age was (34 ± 4) weeks (24-46 weeks), and birth weight was (2 106 ± 743) g (730-4 900 g) . All the related information about infants accepted examinations was screened, inquired and recorded carefully, such as gestation age, birth weight, continuous inhalation of oxygen and respirator applied records.Whether they had asphyxia, hypoxic-ischemic encephalopathy, acute respiratory distress syndrome, pneumonia, jaundice, anemia, congenital heart disease was also recorded. Moreover the physical situations of maternity including gestational hypertension, premature rupture of amniotic fluid, placenta abruption and placenta previa were also assessed. Percentiles (P90 and P95) of birth weight in ROP infants were calculated. Birth weight over 2 000 g in ROP patients was identified as high birth weight, whereas birth weight less than 2 000 g was confirmed as low birth weight. Clinical characteristics were compared in the two groups. T-test, Chi-square test, and Fisher's exact test were used for this study.In all the infants examined, 243 cases were screened out as ROP patients with different stages. The positive rate was 13.0%. Among them, 96 cases needed to be treated which was 39.5%. They were severer than pre-threshold Type I. P90 and P95 of birth weight percentiles of these ROP infants were 2 060 g and 2 240 g.If birth weight less than 2 000 g was confirmed as screen guideline, 9.9% patients might be excluded. There were 24 ROP infants whose birth weight were over 2 000 g with gestation age of (33 ± 3) weeks (28-40 weeks) , and with birth weight of (2 411 ± 354) g (2 100-3 300 g) .Six of them needed to be treated, which was 6.3%. Compared with ROP infants with low birth weight, they had almost same stages and risk factors.High birth weight ROP infants occupies some proportions in Xi'an area. They has no special characteristics or severity compared with low birth weight ones.

In this paper, an underwater robot for inspecting and maintaining nuclear reactor vessel is developed. Based on the kinematics analysis of the robot, the workspace is obtained. In order to evaluate the influence of water environment to the robot, the hydrodynamic forces including water resistance and additional mass force are analyzed. Then some experiments including watertight test are performed to evaluate the performance of the robot and simulations are carried out to verify the theoretical analysis. The experimental and simulation results show that the developed underwater robot which can work at 22m in water meets the design objective basically and the analyses on kinematics and hydrodynamic forces are reasonable.