Quantitative Measurements of Vessel Density and Blood Flow Areas Primary Angle Closure Diseases: A Study of Optical Coherence Tomography Angiography

(1) Purpose: To measure the change in vessel density (VD) and the flow area (FA) on the retina of eyes with primary angle-closure diseases (PACD), including primary angle-closure suspect (PACS), primary angle-closure (PAC), acute primary angle-closure (APAC) and primary angle-closure glaucoma (PACG). (2) Methods: Patients with PACD were prospectively enrolled in this study. All participants underwent thorough ophthalmic examinations. The mean defect (MD), retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) thickness, VD measurement, and blood FA were measured. (3) Results: A total of 147 eyes from 121 subjects were included in this study. The VD of the nerve head layer was significantly lower in PACG and APAC (all p < 0.001). APAC and PACG had lower FA of all layers, except for the choroid layer (p < 0.05). The macular VD of the whole image and blood FA in the superficial layer was significantly lower in PACG (all p < 0.001). The MD, RNFL, and GCC thickness demonstrated a strong correlation with whole image VD in the superficial layer (p < 0.001), while the inside disc VD did not show a significant correlation with MD, RNFL, and GCC thickness (p > 0.05). (4) Conclusions: There was a significant decrease in the VD and FA on the optic disc as well as the VD and FA of the superficial layer in the macular area in APAC and PACG. The changes in VD and FA are correlated with the severity of the glaucomatous structural damage and functional impairment

A Highly Accurate Method for Deformation Reconstruction of Smart Deformable Structures Based on Flexible Strain Sensors

Smart deformable structures that integrate designing, sensing, and controlling technology have been widely applied in the fields of aerospace, robotics, and biomedical engineering due to their multi-functional requirements. The deformation reconstruction method essential for security monitoring and shape controlling, especially for the large deflection deformation, remains a challenge on accuracy and efficiency. This paper takes a wind tunnel’s fixed-flexible nozzle (FFN) plate as the research object to develop a highly accurate deformation reconstruction method based on sensing information from flexible strain sensors. The mechanical behaviors of the FFN plate with large deflection deformation, which is modeled as a cantilever beam, are studied to analyze the relationship of the strain and moment. Furthermore, the large deflection factor and shell bending theory are creatively utilized to derive and modify the strain–moment based reconstruction method (SMRM), where the contour of the FFN plate is solved by particular elliptic integrals. As a result, structural simulation based on ABAQUS further demonstrates that the reconstruction error of SMRM is 21.13% less than that of the classic Ko-based reconstruction method (KORM). An FFN prototype accompanied by customized flexible sensors is developed to evaluate the accuracy and efficiency of the SMRM, resulting in a maximum relative error of 3.97% that is acceptable for practical applications in smart deformable structures, not limited to the FFN plate

Strong Magnetic Units for a Wind Power Tower Inspection and Maintenance Robot

For developing a climbing robot which is used to inspect and maintain a wind power tower, the magnetic unit is one of the key components. Based on analysis of the working conditions of the robot, the approach in this paper is to use four common kinds of magnetic units for adapting to the conical surface. The magnetic circuit of these units is given by theory analysis and is simulated using ANSYS. Moreover, the magnetic force is analysed in detail and the results prove that the magnetic force is greatly influenced by the gap between the unit and the wall surface. In this paper, the design procedures and selection criteria based on the analytical results are given. Meanwhile, these units are compared with each other with the aid of ANSYS. From the results of this comparison, it can be ascertained that the unit using Installation C has the better performance. Furthermore, the effectiveness of the magnetic unit using Installation C is verified by a prototype. The simulations and experiments show that the magnetic unit can allow the robot to keep in contact with the conical wall surface as well as the plane wall surface

Mechanical Behaviors of the Origami-Inspired Horseshoe-Shaped Solar Arrays

The importance of flexibility has been widely noticed and concerned in the design and application of space solar arrays. Inspired by origami structures, we introduce an approach to realizing stretchable and bendable solar arrays via horseshoe-shaped substrate design. The structure has the ability to combine rigid solar cells and soft substrates skillfully, which can prevent damage during deformations. The finite deformation theory is adapted to find the analytic model of the horseshoe-shaped structure via simplified beam theory. In order to solve the mechanical model, the shooting method, a numerical method to solve ordinary differential equation (ODE) is employed. Finite element analyses (FEA) are also performed to verify the developed theoretical model. The influences of the geometric parameters on deformations and forces are analyzed to achieve the optimal design of the structures. The stretching tests of horseshoe-shaped samples manufactured by three-dimensional (3D) printing are implemented, whose results shows a good agreement with those from theoretical predictions. The developed models can serve as the guidelines for the design of flexible solar arrays in spacecraft

Evaluating Eye Drop Instillation Technique and Its Determinants in Glaucoma Patients

Aim. To evaluate eye drop instillation technique and to explore its determinants in glaucoma patients. Methods. One hundred and thirteen patients diagnosed with glaucoma and self-administering topical antiglaucoma eye drops for at least 1 month were evaluated. All patients instilled artificial tear solution in one eye as they would do at home. The whole process was evaluated by two study staff. A comprehensive score system associated with eye drop instillation techniques was used to quantify the instillation technique and explore its determinants such as demographic and clinical characteristics. Results. Half of the patients (48.67%) finished the administration of eye drop on first attempt.1.7 eye drops were squeezed out on average. 43 patients (37.17%) got contact with ocular surface or adnexa. Only 19.7% patients had eye drop instillation techniques being defined as well. 11 patients (9.7%) had prior instruction regarding using eye drops, while only 4 patients knew to occlude the tear duct by pressing the dacryocyst area. Older age and worse visual acuity were found to be independent risk factors for worse instillation technique. Conclusions. Eye drop instillation technique in glaucoma patients deserves great attention from eye care practitioners during their lifelong follow-up, especially those aged older and have worse visual acuity

Field control technologies of combustion assisted gravity drainage (CAGD)

Abstract: The targets, strategies and approaches of the field controlling processes of combustion assisted gravity drainage (CAGD) are discussed based on the research of its mechanisms, advantages and defects. By taking fully advantage of gravity, CAGD process can produce the mobilized oil near the combustion front through the underlying horizontal well, serving as a possible solution for extra-heavy oil production in Xinjiang oil field. However, unidirectional conning and breakthrough of combustion front are risky to happen during the field application of CAGD. Based on laboratory three-dimensional physical simulation experiments and the experience of former pilots, it is proposed that a gently upward sloping combustion front is beneficial for the steady drainage of mobilized oil and should be the target of CAGD control. Key production parameters like the maximum production rate and corresponding air injection rate during field application are calculated with reservoir engineering approach and material balance theory. The maximum oil production rate of the CAGD pilot in Block Fengcheng, Xinjiang oil field, is 12.9 m3/d, and the air injection rate is 14 048 m3/d. To maximize the oil productivity and sustain combustion front moving forward steadily, the ignition position should be located at the mid-upper parts of the formation; the air injection rate at the early stage should keep slow and increase gradually; meanwhile, the production rate of flue gas should be 90% of the air injection rate. A pilot of CAGD was initiated in the Xinjiang Fengcheng Field on the basis of those research outcomes. By the end of 2016, Well Group FH005 in the pilot has succeeded in steady production for more than 400 days. Key aspects, involving the shape of combustion chamber, oil production of single horizontal producer, air oil ratio and the degree of oil upgrading are in accordance with what the development plan predicted. Key words: super-heavy oil reservoir, fire flooding, combustion assisted gravity drainage, physical simulation, pilo

Correction: Ning et al. Deep Vision Servo Hand-Eye Coordination Planning Study for Sorting Robots. <i>Symmetry</i> 2022, <i>14</i>, 152

In the original publication [...

Noncontact Conjunctiva: A Better Mitomycin C Application Site for Trabeculectomy

Abstract Introduction Bleb scarring is the most important complication of trabeculectomy. Changing the application position of mitomycin C (MMC) during trabeculectomy might affect the surgery outcome. Our aim is to compare the effectiveness and safety of intraocular pressure (IOP) lowering in two different application sites of mitomycin in trabeculectomy. Methods This retrospective trial compared the surgical outcomes of 177 eyes that underwent trabeculectomy with adjunctive mitomycin C. In 70 eyes, an MMC-soaked sponge was applied under the scleral flap without touching Tenon’s capsule. In 107 eyes, an MMC-soaked sponge was applied under the scleral flap covered by Tenon’s capsule. Outcome measures were the IOP, best-corrected visual acuity (BCVA), success rates, and incidence of complications. Results Within both groups, a highly significant IOP reduction was seen during follow-up. The effectiveness in reducing IOP and the change in best-corrected visual acuity (BCVA) were similar between the two groups. Thin-walled blebs and postoperative hypotony were seen more often when MMC-soaked sponges were applied under the scleral flap covered by Tenon’s capsule (P = 0.008 and P = 0.012, respectively). There was no significant difference in BCVA or other complications in either group. Conclusion Since the effectiveness of IOP reduction was similar between both groups and with a low incidence of thin-walled blebs and hypotony, the subscleral application without touching Tenon’s capsule seems to be the safer application site of MMC during trabeculectomy

Preparation carbon nanotube-decorated carbon fibers under low pressure for epoxy-based unidirectional hierarchical composites with enhanced interlaminar shear strength

Multi-walled carbon nanotubes (CNTs) were grown in-situ on the surface of carbon fibers (CFs) at low pressure by a vertical chemical vapor deposition (CVD) reactor. The surface of CFs was modified by electrochemical anodization, and the growth morphology and other properties of CNTs were analyzed by detailed techniques. The CNT-grown CF reinforced unidirectional hierarchical composite material based on the epoxy resin was prepared. The interlaminar shear strength (ILSS) indicates that the maximum strength of the composites reaches 108 MPa after the CNTs are grown on the CF surface with a 25.2% increase than that of the desized CF composites. The fracture surface of composites was observed by scanning electron microscopy (SEM) to further understand the interfacial fracture behavior and enhancement mechanism of CNTs-CF/epoxy composites. The significant improvement in the overall performance of the hierarchical composites can be attributed to the increased adhesion of the interface between the fibers and the resin. The presence of CNTs can restrict the molecular movement of the resin and achieve a strong anchoring interaction, thereby increasing the strength and toughness of the composites and reducing the stress concentration between the layers