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ObjectiveAn ankle arthritis with medial gutter obliteration is known to have good results after joint preservation surgery. However, the diagnosis is often missed on radiographs. The aims of this study were to investigate sensitivity of radiographs in the identification of medial gutter arthritis, incidence and direction of the talar tilt on weightbearing CT (WBCT), and to assess radiographic alignment of the medial gutter arthritis.Materials and methodsRadiographic data was retrospectively evaluated in 102 ankles which were diagnosed medial gutter arthritis by using the WBCT at our clinic between January 2017 and June 2019. Among the 102 ankles, proportion of ankles which showed medial gutter arthritis on plain radiograph was obtained. The presence and direction of talar tilt were assessed on three coronal WBCT images at the anterior, middle, and posterior aspect of the ankle. Plain radiographic parameters were compared between the 102 ankles and control group.ResultsPlain radiograph showed medial gutter arthritis only in 63 ankles (62%) among the 102 ankles. Most of the ankles with medial gutter arthritis showed talar tilt on WBCT, and about half of all ankles showed valgus talar tilt at the anterior aspect of ankle on WBCT. In ankles with medial gutter arthritis, the mechanical axis of the lower extremity and the tibial plafond were varus angulated and the talus was medially translated compared to the control group.ConclusionRadiographs were less sensitive than WBCT in demonstrating medial gutter arthritis. Anterior aspect of ankles with medial gutter arthritis often showed valgus direction of talar tilt. Varus mechanical axis deviation and varus tibial plafond are commonly associated with the medial gutter arthritis.

The miniaturization of droplet manipulation methods has led to drops being proposed as microreactors in many applications of biology and chemistry. In parallel, microfluidic methods have been applied to generate monodisperse emulsions for applications in the pharmaceuticals, cosmetics, and food industries. To date, microfluidic droplet production has been dominated by a few designs that use hydrodynamic forces, resulting from the flowing fluids, to break drops at a junction. Here we present a platform for droplet generation and manipulation that does not depend on the fluid flows. Instead, we use devices that incorporate height variations to subject the immiscible interfaces to gradients of confinement. The resulting curvature imbalance along the interface causes the detachment of monodisperse droplets, without the need for a flow of the external phase. Once detached, the drops are self-propelled due to the gradient of surface energy. We show that the size of the drops is determined by the device geometry; it is insensitive to the physical fluid properties and depends very weakly on the flow rate of the dispersed phase. This allows us to propose a geometric theoretical model that predicts the dependence of droplet size on the geometric parameters, which is in agreement with experimental measurements. The approach presented here can be applied in a wide range of standard applications, while simplifying the device operations. We demonstrate examples for single-droplet operations and high-throughput generation of emulsions, all of which are performed in simple and inexpensive devices.

Industrial thin-film composite (TFC) membranes achieve superior gas separation properties from high-performance selective layer materials, while the success of membrane technology relies on high-performance gutter layers to achieve production scalability and low-cost manufacturing. However, the current literature predominantly focuses on the design of polymer architectures to obtain high permeability and selectivity, while the art of fabricating gutter layers is usually safeguarded by industrial manufacturers and appears lackluster to academic researchers. This is the first report aiming to provide a comprehensive and critical review of state-of-the-art gutter layer materials and their design and modification to enable TFC membranes with superior separation performance. We first elucidate the importance of the gutter layer on membrane performance through modeling and experimental results. Then various gutter layer materials used to obtain high-performance composite membranes are critically reviewed, and the strategies to improve their compatibility with the selective layer are highlighted, such as oxygen plasma treatment, polydopamine deposition, and surface grafting. Finally, we present the opportunities of the gutter layer design for practical applications. [Display omitted] •First report to provide a comprehensive review of gutter layers for TFC membranes for gas separation.•Elucidate the importance of gutter layers to membrane performance by modeling and experiments.•Exhaustively review state-of-the-art materials used for gutter layers.•Highlight surface-engineering strategies to improve compatibility between gutter layers and selective layers.

Mosquitoes pose health risks to human populations by serving as vectors of diseases. Mosquito control organizations are responsible for inspecting and controlling vector populations to reduce the risk of infection of these diseases. Current sampling methods are effective for numerous types of mosquito habitat, but not conducive for sampling small overhead habitat such as roof gutters or tree holes. We have developed and tested a tool called the Mosquito GutterSnipe to sample these overhead habitats. Volumetric and larval capacity testing of the tool prototype demonstrated comparable sampling integrity to standard mosquito dipping methods. The GutterSnipe can be employed as a reliable way to sample previously overlooked mosquito habitat. Its current model is cost effective and easy to produce for mosquito control organizations and easy to use for inspectors.

Experiments on fuel effects flame stabilization processes, NOx generation and temperature at combustion chamber outlet when using a group of three V-gutter flame holders have been reported. Fuel supply directly to the re-circulation zone on the inside of the V-gutter (type A fuel supply), and alternatively in the second type, fuel was supplied to the V-gutter symmetry axis on the outside (type B fuel supply have been carried out. nema

To evaluate structural alterations and healing responses in the trabecular meshwork region with optical coherence tomography (AS-OCT) following after gonioscopy assisted transluminal trabeculotomy (GATT) and microincisional trabeculectomy (MIT). 73 eyes of 67 patients (M:F = 45:22) with ≥6 months of follow-up after MIT (n = 41) or GATT (n = 32) with or without combined cataract surgery were included for this prospective study. The angle as seen on AS-OCT at 1, 3, 6 months after surgery were evaluated for structural alterations like peripheral anterior synechiae (PAS), hyphema, and hyperreflective scarring responses. The scarring was graded according to the linear extent measured from the centre of the trabecular meshwork (TM) gutter to the sclera/cornea as mild (<250μ), moderate (250-500μ), and severe(˃500μ), while the pattern of scarring was graded as open saucer/gutter, closed gutter, and trench pattern. The association of the need for medication or surgical outcome and clinical variables and AS-OCT parameters including the pattern and severity of scarring were analysed using multivariate regression. All eyes achieved significant reduction of IOP and number of medications with a final IOP of 15±3.2mm Hg at a mean follow-up of 8±32. months. While mild scarring was seen more common in MIT, severe scarring was seen in >65% of GATT eyes compared to 31% of MIT eye, p<0.001. An open saucer was equally seen in MIT and GATT while the trench pattern was more commonly seen in GATT eyes (>50%). Severe scarring in a trench pattern seemed to predict the need for medications for IOP control, though they independently did not seem to influence the final IOP or surgical outcome. A severe form of scarring in a trench pattern on AS-OCT predicted the need for glaucoma medications after MIGS surgery. Regular monitoring of the scarring responses by AS-OCT and clinical examination are necessary to identify those at need for medications after MIGS.

Gutters made of glass-fibre-reinforced polymer (GFRP) are usually produced with a three-millimetre thickness. The fillers are mixed into unsaturated polyester (UP) resin, which is intended to make the composite material more affordable. This study aims to examine the effects of the addition of alumina trihydrate (ATH), calcium carbonate (CC), and a mixture of ATH and CC of 15 and 30 parts per hundredweight of resins (PHR) on the material properties of the three-millimetre-thick three-layered GFRP composites. The properties observed included physical properties, namely, specific gravity and water absorption, chemical properties such as burning rate, and mechanical properties such as hardness, flexural strength, and toughness. The effects of the fillers on the voids and interfacial bond between the reinforcing fibre and matrix were analysed using the flexural fracture observation through scanning electron microscopy (SEM). The results showed that the addition of fillers into the UP resin led to an increase in the density, hardness, flexural strength, modulus of elasticity, and toughness but a decrease in water absorption and burning rate in a horizontal position. This information can be helpful for manufacturers of gutters made of GFRP in selecting the appropriate constituent materials while considering the technical and economic properties.

In this paper, a new method of simultaneous die and preform optimization is proposed for closed die forging of nearly plane-strain components with complex geometry along their axes. In this method, using two-dimensional finite element simulations and the response surface method, optimal values for the width and thickness of the flash land and the amount of additional material in each of the main sections are obtained. Accordingly, using the variable gutter technique, the preform and dies are designed based on the optimization goal. To investigate the usefulness of the method in three optimization approaches, including the minimum forging force, the minimum excess material, and a balance between the forging force and the excess material, the values of forging load, waste material, die stress, deformation, heat distribution, material flow, and die wear were determined numerically and compared to the conventional method. The results showed that the presented method can save up to 60% in forging force and up to 51.5% in excess material compared to the conventional method. It can also minimize die wear by up to 74% and die stress by up to 50%. Finally, the numerical results showed that a balanced mode between the minimum forging load and the minimum excessive materials can be chosen as the most appropriate selection for practical purposes. Graphic Abstract

Objectives We present a 3-D approach to joint space width (JSW) measurement across the ankle from weight-bearing CT (WBCT) to demonstrate inter-operator reproducibility, test-retest repeatability, and how differences in angulation affect ankle JSW distribution. Methods One side from repeat WBCT imaging of both feet and ankles was analysed from 23 individuals as part of their routine clinical care pathway. Joint space mapping was performed at four facets across the talus: talonavicular, talar dome and medial gutter (dome-medial), lateral gutter, and posterior subtalar. Inter-operator reproducibility was calculated for two users, while test-retest repeatability was calculated by comparing the two visits, both presented as Bland-Altman statistics. Statistical parametric mapping determined any significant relationships between talocrural joint space angulation and 3-D JSW distribution. Results The average ± standard deviation interval between imaging was 74.0 ± 29.6 days. Surface averaged bias ± limits of agreement were similar for reproducibility and repeatability, the latter being: talonavicular 0.01 ± 0.26 mm, dome-medial 0.00 ± 0.28 mm, lateral gutter − 0.02 ± 0.40 mm, and posterior subtalar 0.02 ± 0.34 mm. Results are presented as 3-D distribution maps, with optimum test–retest repeatability reaching a smallest detectable difference of ± 0.15 mm. Conclusions Joint space mapping is a robust approach to 3-D quantification of JSW measurement, inter-operator reproducibility, and test–retest repeatability at the ankle, with sensitivity reaching a best value of ± 0.15 mm. Standardised imaging protocols and optimised metal artefact reduction will be needed to further understand the clinical value of these 3-D measures derived from WBCT. Clinical relevance statement Weight-bearing computed tomography is an increasingly important tool in the clinical assessment of orthopaedic ankle disorders. This paper establishes the performance of measuring 3-D joint space width using this technology, which is an important surrogate marker for severity of osteoarthritis. Key Points • Joint space width values and error metrics from across the ankle measured from weight-bearing CT can be presented as 3-D maps that show topographic variation . • The best sensitivity for detecting meaningful change in 3-D joint space width at the ankle was  ±  0.15 mm, a value less than the isotropic imaging voxel dimensions . • Standardised imaging protocols and optimised metal artefact reduction will be needed to understand the clinical value of 3-D measures from weight-bearing CT .

Metal-organic framework (MOF) nanosheets are promising candidates for molecular sieve because of their structural diversity and minimized mass transfer barrier. However, design of appropriate MOF nanosheets and preparation of high-performance MOF nanosheet-based membranes, especially for gas separation, remains great challenges. Structural degradation may simultaneously occur with conventional exfoliation method, which has hindered its widespread application in high-performance molecular sieve membrane preparation. Even if nanosheets could be stacked, grain boundaries would form between the nanosheets, which could be applied to liquid separation but not to gas separation. To address these challenges, we applied bottom-up growth of Zn2(benzimidazole)4 nanosheet to fabricate defect-free membranes. Zn2(benzimidazole)4 is composed of benzimidazole-zinc tetrahedral units and layers are connected by van der Waals interaction. At first, the Zn2(benzimidazole)4 nanosheets were deposited onto a porous support to prepare gutter layer. Next, Zn-based amorphous layer was coated on the gutter layer and crystallized by benzimidazole vapor treatment. Highly oriented Zn2(benzimidazole)4 nanosheet based membranes were fabricated by anisotropically controlling crystallization. The prepared Zn2(benzimidazole)4 nanosheet-based membranes show separation performance in hydrogen purification with H2/O2 ideal separation factor of 11.6 and H2 permeance of 5650 GPU.