Reverse Configuration Research Articles

Deep Learning-Accelerated Designs of Tunable Magneto-Mechanical Metamaterials.

Metamaterials are artificially structured materials with unusual properties, such as negative Poisson's ratio, acoustic band gap, and energy absorption. However, metamaterials made of conventional materials lack tunability after fabrication. Thus, active metamaterials using magneto-mechanical actuation for untethered, fast, and reversible shape configurations are developed to tune the mechanical response and property of metamaterials. Although the magneto-mechanical metamaterials have shown promising capabilities in tunable mechanical stiffness, acoustic band gaps, and electromagnetic behaviors, the existing demonstrations rely on the forward design methods based on experience or simulations, by which the metamaterial properties are revealed only after the design. Considering the massive design space due to the material and structural programmability, a robust inverse design strategy is desired to create the magneto-mechanical metamaterials with preferred tunable properties. In this work, we develop an inverse design framework where a deep residual network replaces the conventional finite-element analysis for acceleration, realizing metamaterials with predetermined global strains under magnetic actuations. For validation, a direct-ink-writing printing method of the magnetic soft materials is adopted to fabricate the designed complex metamaterials. The deep learning-accelerated design framework opens avenues for the designs of magneto-mechanical metamaterials and other active metamaterials with target mechanical, acoustic, thermal, and electromagnetic properties.

Label-Free, Versatile, Real-Time, and High-Throughput Monitoring of Tyrosine Phosphorylation Based on Reversible Configuration Freeze

Label-Free, Versatile, Real-Time, and High-Throughput Monitoring of Tyrosine Phosphorylation Based on Reversible Configuration Freeze

Engineering the simply asymmetric Morita–Baylis–Hillman reactions in a sodium phosphate buffer system: from enzyme‐ to proline‐catalyzed transformation

AbstractBACKGROUNDThe Morita–Baylis–Hillman (MBH) reaction is an important carbon–carbon bond‐forming reaction. However, most MBH reactions suffer disadvantages such as high amounts of catalyst and hazardous solvents, long reaction time, low reactivity and selectivity. In this study, simple, cost‐effective and eco‐friendly asymmetric MBH reactions are developed.RESULTSFollowing our previous study that the commercial Candida antarctica lipase B (lipase CalB)‐catalyzed MBH reaction can be activated by introducing an amide compound as a co‐catalyst, the recombinant lipase CalBs (rCalBs) with polyamino acid tails are first attempted to be used in the same MBH reaction, but unfortunately chiral MBH products are not obtained. Enoate reductase (ER) is found to give asymmetric transformation of the MBH reaction with a conversion of 36.9% and enantiomeric excess (e.e.p) of 6.8% when other enzyme resources are expanded. According to the observation that the surface amino acids of ER may be key factors in achieving the MBH reaction, single amino acids are subsequently selected to catalyze the MBH reactions, and the reverse configuration of (R)‐ and (S)‐MBH products with e.e.p of 63.9% and 62.1% for single l‐proline‐ and d‐proline‐catalyzed MBH reactions are reached only in 4 h, respectively.CONCLUSIONProline can afford the asymmetric MBH reaction in a sodium phosphate buffer only in 4 h without the help of the other co‐catalyst in our study, which is superior to those reported. The study aims to introduce a novel phenomenon observed from enzyme‐catalyzed to proline‐catalyzed MBH reactions. © 2022 Society of Chemical Industry (SCI).

“Aortic Balloon Molding” during Ovation Endograft Implantation Expands Graft Use for Hostile Neck Anatomy

Challenging aortoiliac anatomy such as short neck and narrow access vessels is responsible for endovascular repair of abdominal aortic aneurysm (EVAR) ineligibility in up to 50% of cases. The Ovation stent graft helped widen the range of abdominal aortic aneurysms (AAAs) suitable for EVAR thanks to its low-profile delivery system and polymer-filled sealing rings. However, its advantages are offset by a tight sizing chart that can lead to increased risk of type Ia endoleak or endograft infolding from under- or oversizing, respectively. We sought to assess the safety and efficacy of a novel endovascular technique developed to expand the use of the Ovation endograft while avoiding these issues. We conducted a retrospective review of all patients who underwent EVAR with the Ovation endograft at our institution between March 2019 and December 2020. "Aortic Balloon Molding" or ABM is a novel endovascular technique in which the graft is pre-cannulated and a compliant aortic balloon is inflated at the site of the graft's sealing rings during polymer administration. The technique was preferentially performed in patients with hostile neck anatomy (HNA) defined as any or all of angulation >60°, reverse taper configuration, ≥50% circumferential thrombus, or calcification. Patients undergoing traditional deployment were compared to those in whom ABM was performed. End points included neck-related adjunctive procedures, technical success, type Ia endoleak at completion angiogram, and 1-year freedom from type Ia endoleak and migration. A total of 43 patients were included in the study, of which 26 (60.5%) were treated with the ABM technique. Mean follow-up was 7.9±6months. Patients in the ABM group were more likely to have a reverse taper neck (61.5% vs. 41.2%, P=0.1), have significant circumferential thrombus or calcium (23.1% vs. 5.9%, P=0.1), and be treated outside of the Ovation indications for use regarding anatomic characteristics (65.4% vs. 41.2%, P=0.1). Technical success was achieved in 100% of cases. However, patients in the ABM group were less likely to require a neck-related adjunctive procedure (7.7% vs. 23.5%, P=0.1). Only 1 type Ia endoleak was observed at completion angiogram in a patient treated without ABM. At 1 year, freedom from type Ia endoleak or migration was 100% for both groups. ABM proves to be a safe and effective adjunctive technique for the treatment of AAAs with HNA using the Ovation stent graft. This may allow optimal endograft sizing to achieve adequate seal in complex aortic anatomies. Further research is warranted to evaluate the long-term outcomes of this technique.

Investigation of AlN/Si based heterogeneous Junction using inter-digitated electrodes for enhanced UV light detection

A 200 nm thick AlN layer is fabricated by Hydride Vapor Phase Epitaxial (HVPE) technique onto the n-type Silicon < 111 > wafer. After epitaxial growth the AlN is masked and 100 nm thick interdigitated electrodes of Silver are deposited by the atomistic scaled Physical Vapor Deposition (PVD) system. These interdigitated electrodes are further examined with five possible circuit configurations of AlN/Silicon under multiple biases and temperatures. Different electrical and electro-optical characterization such as Current-Voltage, Charge Deep Level Transient Spectroscopy and Kinetics of Dark and UV current; have been performed for each configuration. For all such cases the Ultra-Violet (UV) light has been sensed and found that the reversed biased silicon coupled with interdigitated AlN schemes may provide largest responsivity under both photovoltaic and photoconductive modes. Also, the photo-conversion gain (ratio of UV Current / Dark Current) of each case under different physical conditions have also been emulated and found that the same reverse biased configuration leads higher extent of photo-conversion gain. The charge based transient analysis using (Q-DLTS) have been performed for all said configurations and it is found that the same reverse biased scheme offers largest magnitude of capture cross section i.e. ~ 10−18 cm2, which may capture larger extent of free charge carriers in UV mode and could be opted for enhanced UV light detection.

Effect of the Streamwise Orientation of a Pair of Vortex Generator on the Flow and Heat Transfer Characteristics in a Plain Channel

Abstract For a rectangular channel flow, a variant of delta winglet vortex generator (VG) in common flow up (CFU) orientation is presented to enhance the thermal performance factor by decreasing the friction losses. The new vortex generator is a simple reversal of a standard CFU orientation such that the leading edge and suction side of the conventional CFU orientation of the winglet become the trailing edge and pressure side for the reverse common flow up (RCFU) orientation of the winglet, respectively. Numerical simulations were carried out for a three-dimensional, steady, laminar, and incompressible rectangular channel flow with and without the two VG configurations. Performance analysis was done for global Nusselt number and friction factor for different inter-winglet spacings of the VG pair at a Reynolds number of 1478. An increase of 2.3% in the thermal enhancement factor was achieved in RCFU compared to CFU orientation at an inter-winglet spacing equal to 0.02 times the channel height. At the highest inter-winglet spacing equal to 0.6 times the channel height, the CFU orientation exhibited a gain of 3.2% in the enhancement factor over the RCFU orientation. Heat transfer downstream of the vortex generator was shown to be impacted in the reverse configuration (RCFU) due to stronger vortex formation compared to a standard CFU configuration at the least inter-winglet spacing.

Deployable mechanical metamaterials with multistep programmable transformation

Transformations in shape are critical to actuation in engineered metamaterials. Existing engineering metamaterials are typically limited to a small number of shape transformations that must be built-in during material synthesis. Here, inspired by the multistability and programmability of kirigami-based self-folding elements, a robust framework is introduced for the construction of sequentially programmable and reprogrammable mechanical metamaterials. The materials can be locked into multiple stable deployed configurations and then, using tunable bistability enabled by temperature-responsive constituent materials, return to their original reference configurations or undergo mode bifurcation. The framework provides a platform to design metamaterials with multiple deployable and reversible configurations in response to external stimuli.

Cement-and-pebble nanofluidic membranes with stable acid resistance as osmotic energy generators

Osmotic energy between river water and seawater has attracted interest as a new source of sustainable energy. Nanofluidic membranes in a reverse electrodialysis configuration can capture energy from salinity gradients. However, current membrane materials suffer from high resistances, low stabilities, and low charge densities, which limit their further application. Here, we designed a high-performance nanofluidic membrane using carboxylic cellulose nanofibers functionalized with graphene oxide nanolamellas with cement-and-pebble microstructures and stable skeletons for enhanced ion transmembrane transport. By mixing artificial river water and seawater, the composite membrane achieved a high output power density up to 5.26 W m−2. Additionally, the membrane had an excellent acid resistance, which enabled long-term use with over 67 W m−2 of power density. The performance of this composite membrane benefited from the mechanically strong cellulose fibers and the bonding between nanofibers and nanolamellas. In this work, we highlight promising directions in industrial waste treatment using energy extracted from chemical potential gradients.

A partially underground rock bed thermal energy storage with a novel air flow configuration

Low-cost, grid-level energy storage is key to maximizing the utilization of renewable energy production and decarbonizing the electricity sector. The design and testing of a high-temperature thermal energy storage based on rocks is presented. Important design features are the three electric heaters mounted on top of the storage and the inner pipe inside the rock bed, allowing for the first time a reversible vertical air flow configuration of a system which is partially underground. The rock bed storage is highly scalable and based on diabase which is abundant as well as low-cost in Northern Europe and other locations. A pilot plant with a storage capacity of 1 MWhth has been operated up to 675°C. The first law round-trip efficiency of 70.7% in an initial operation exceeds all efficiencies observed in a previously built thermal storage with horizontal flow configuration. By improving the operation with charge and discharge air flow rates of 140 and 300 Nm/h3, respectively, the first law round-trip efficiency increases to 80.7%. A maximum thermal output of 58.06 kW is achieved, of which 90% can already be provided within 6 min of start-up. This paper demonstrates that the novel medium-scale storage can operate with a satisfactory performance for several years with no failures to date.

Impacts of transmembrane pH gradient on nanofluidic salinity gradient energy conversion

Solution pH can impact the nanochannel surface charge density, thus, to regulate the transmembrane ion transportation. Here, the performance of nanofluidic salinity gradient energy conversion is investigated, where the solution pH at the high/low concentration side varies separately, rendering asymmetric pH configurations. Results reveal that the solution pH at the low concentration side (pHL) exhibits a significant impact on the salinity gradient energy conversion. When pHL < Isoelectric Point (IEP), the energy conversion indicators are most stable under various solution pH at the high concentration side (pHH). The surface charge density of the nanochannel at the low concentration end determines the transmembrane ion transportation characteristics, dominating the energy conversion performance. The energy conversion performance via nanochannels of different lengths under asymmetric pH configurations is also studied. There exists optimal nanochannel length corresponding to the maximum electric power, which differs under various pH configurations. For longer nanochannels, the ion concentration polarization effect is weakened, allowing for a more effective energy extraction performance via pH-adjusted salinity gradients. At the length of 2000 nm, the electric power and energy conversion efficiency under the co-direction configuration is 78% and 97.9%, respectively, larger than those under the reverse direction configuration.

Biomechanical Evaluation of an Oblique Lateral Locking Plate System for Oblique Lumbar Interbody Fusion: A Finite Element Analysis

The oblique lateral locking plate system (OLLPS) is a novel internal fixation with a locking and reverse pedicle track screw configuration designed for oblique lumbar interbody fusion (OLIF). The OLLPS is placed in a single position through the oblique lateral surgical corridor to reduce operative time and complications associated with prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of the OLLPS. An intact finite element model of L1-S1 (intact) was established based on computed tomography images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately based on OLIF surgical procedures and different internal fixations: 1) stand-alone OLIF (SA); 2) OLIF with a 2-screw lateral plate; 3) OLIF with a 4-screw lateral plate; 4) OLIF with OLLPS; and 5) OLIF with bilateral pedicle screw fixation (BPS). After validation of the intact model, physiologic loads were applied to the superior surface of L1 to simulate motions such as flexion, extension, left bending, right bending, left rotation, and right rotation. The evaluation indices included the L4/5 range of motion, the L4 maximum displacement, and the maximum stresses of the superior and inferior end plates, the cage, and the supplemental fixation. During OLIF surgery, the OLLPS provided multiplanar stability similar to that provided by BPS. Compared with 2-screw lateral plate and 4-screw lateral plate, OLLPS had better biomechanical properties in terms of enhancing the instant stability of the surgical segment, reducing the stress on the superior and inferior end plates of the surgical segment, and decreasing the risk of cage subsidence. With a minimally invasive background, the OLLPS can be used as an alternative to BPS in OLIF and it has better prospects for clinical promotions and applications.

Out-of-equilibrium supported Pt-Co core-shell nanoparticles stabilized by kinetic trapping at room temperature

The chemical stability of supported CoPt nanoparticles in out-of-equilibrium core-shell configurations was investigated mainly by anomalous grazing incidence small angle X-ray scattering (AGISAXS) in association with combined transmission electron microscopy and X-ray absorption spectroscopy. CoPt nanoparticles were prepared at room temperature by ultrahigh vacuum atom beam deposition using two different routes: simultaneous deposition of the two metals (CoPt) or sequential deposition. In this last case, Co deposition on a Pt-core (Pt@Co) and the reverse configuration (Co@Pt) are explored. In the Pt@Co case, our experimental analysis of 2.5 nm particles shows the stability of a Pt rich-core (80% Pt) surrounded by a two-monolayers-thick Co shell. In the reverse case, the core-shell structure is also stabilized, while the codeposited sample leads to an alloyed structure. These results suggest that the growth kinetics can trap the thermodynamically non-favorable core-shell structure even for this system which has a high alloying tendency. Besides the lack of atom mobility at room temperature, this stabilization can also be associated with core strain effects. Post thermal treatment of core-shell samples induces a structural transition from the core-shell configuration to the equilibrium alloyed configuration. This study demonstrates that the element-selective scattering technique, AGISAXS is highly efficient for the extraction of chemical segregation information from multi-component supported nanoparticles, such as core-shell structures, up to ultimate small sizes.

Power dependent surface plasmon coupled emission studies of metal-dielectric-metal planar structure

Surface plasmon coupled emission (SPCE) was demonstrated in Metal-Dielectric-Metal Planar (MDMP) structure by coupling MDMP structure to a hemicylindrical prism by Reverse Kretchmann configuration. Here silver and Fluorescein dye dispersed in polyvinyl Alcohol (PVA) were used as metal and dielectric layers respectively. Due to the combined effect of (1) confinement of photon mode within MDMP structure and (2) excitation of plasmon modes by RK configuration, highly directional and enhanced emission was observed. Dependence of SPCE emissions on input excitation power were studied. Higher dielectric thickness (∼600 nm) shows a better emission efficiency as compared to lower dielectric thickness (∼140 nm). Our simulation results show that a higher field distribution within MDMP structure for dielectric thickness of 600 nm resulting in better surface plasmon emission coupling and hence in better emission efficiency.

Implementation Of Docker Container On Local Network By Applying Reverse Proxy

Virtualization is an implementation of a software. Virtualization technology has changed the direction of the computer industrial revolution by reducing capital costs and operating costs. The availability of a virtualization will also increase the availability of higher services and data protection mechanisms. Docker is configured to create multiple containers on a network, each container containing one image. The three containers will be created in one compose where each container is connected to each other for WordPress configuration and two composers will be created. Furthermore, from each compose a reverse proxy configuration is carried out which aims to set a different domain address. Lighten computer performance and can reduce the required storage so as to make hosting more effective and efficient. Containers also provide a security advantage over complete control over management running on separate, isolated containers.

One-dimensional lithium-rich Li1.17Ni0.35Mn0.48O2 cathode and carbon-coated MnO anode materials for highly reversible Li-ion configurations

Many efforts have been devoted to develop both cathode and anode materials with high energy and power densities. In this paper, one-dimensional (1D) Li-rich Li1.17Ni0.35Mn0.48O2 (0.4Li2MnO3∙0.6LiNi0.7Mn0.3O2, LLMNO) cathode and carbon-coated MnO (C@MnO) anode active materials synthesized with the same 1D MnC2O4 precursor nanowires (NWs) were fabricated for use in full lithium-ion batteries (LIBs). As-prepared 1D LLMNO was used as a LIB cathode, which delivered a high capacity (215.8 mAh g−1), improved cyclic lifetime, and notable rate capability. Furthermore, the 1D C@MnO anode exhibited an enhanced capacity (1001.4 mAh g−1), high cycling stability, and excellent rate capability, in comparison with MnO NWs without carbon decorations. While the full LIB consisted of 1D structural LLMNO cathode and C@MnO anode, it showed a high capacity above 178.5 mAh g−1 from 0.1 to 4.2 V at the first cycle. The enhanced Li+ storage properties suggest that these full LIB configurations with 1D LLMNO and C@MnO NWs could be a prospective candidate for practical LIB applications.

Development of a Method for the Measurement of Human Scent Samples Using Comprehensive Two-Dimensional Gas Chromatography with Mass Detection

Every human body is a source of a unique scent, which can be used for medical or forensic purposes. Human skin scent is a complex mixture of more or less volatile compounds with different chemical and physical properties, which often differ significantly in their concentrations. The most efficient technique for separating such complex samples is comprehensive two-dimensional gas chromatography (GC × GC). This work aimed to find the optimal arrangement of a two-dimensional chromatographic system and define a suitable chromatographic method for non-targeted analysis of human scent samples. Four different chromatographic columns (non-polar Rxi-5MS and TG-5HT, medium polar Rxi-17Sil MS and Rtx-200MS) and their different configurations were tested. The best system was the 30 m primary column Rtx-200MS (with the 2 m pre-column Rtx-200MS) and the 1 m secondary column TG-5HT in a reverse configuration. This system achieved the highest theoretical and conditional peak capacities, optimal resolution, and the lowest number of coelutions.

Entry Tear Dominance at CT Angiography Predicts Long-term Clinical Outcomes in Aortic Dissection: Another Piece of the Puzzle.

Entry Tear Dominance at CT Angiography Predicts Long-term Clinical Outcomes in Aortic Dissection: Another Piece of the Puzzle.

Arthroplasty for weight-bearing shoulders

IntroductionRepeated transfers and wheelchair propulsion in patients with a neurological deficit of the lower limbs overloads the upper limbs mechanically, particularly the shoulders, which become weight-bearing. Under these conditions, arthroplasty implants are subjected to large stresses, even though this indication is controversial in such a context. We hypothesized that joint replacement in weight-bearing shoulders will relieve pain and improve range of motion, with a positive impact on function and autonomy, without increasing the complication rate relative to the able-bodied population. Materials and methodsThis retrospective study involved 13 implants in 11 patients (4 total shoulder arthroplasty, 4 hemi-arthroplasty and 3 reverse shoulder arthroplasty) who had a mean follow-up of 33.7 ± 27 months (12-85 months). The clinical assessment included active and passive range of motion, pain, Constant score, and the Wheelchair User's Shoulder Pain Index (WUSPI). Radiographs were evaluated to look for signs of loosening and scapular notching. The patients’ autonomy was evaluated through the number of transfers, means of locomotion (manual or electric wheelchair) and the functional independence measure (FIM). Two subgroups were defined based on the initial pathology: neurological shoulder or functional shoulder. ResultsThe 11 patients had a mean age of 64±19 years (23-85 years) and were all long-term wheelchair users (electrical or mechanical). The pain level on VAS decreased from 8±3 preoperatively to 4±2 postoperatively (p=0.003). The mean Constant score increased 90% from 22±11 preoperatively to 42±23 postoperatively (p=0.008). The WUSPI score decreased by 73% from 80±30 to 21±15 (p=0.001). The range of motion improved in the subgroup of patients with functional shoulders but not in the subgroup of patients with neurological shoulders. The means of locomotion was altered in five patients (63%) by the acquisition of an electric wheelchair, but with no significant change in the number of daily transfers. There were no radiographic signs of implant loosening at the final assessment. Two implants had to be revised: one anatomical prosthesis was converted to a reverse configuration because of a secondary rotator cuff rupture; one case of early infection required a two-stage implant change. DiscussionJoint replacement in weight-bearing shoulders is an effective medium-term solution for cuff tear arthropathy and glenohumeral OA, mainly for addressing pain, with slight improvements in range of motion, depending on the initial pathology. This intervention requires lifestyle adaptations such as changes in daily transfer practices and means of locomotion. Level of evidenceIV, retrospective study.

Synthesis of Dibenzylic Diselenides from Elemental Selenium and Benzylic Quaternary Ammonium Salts

AbstractAbstract: Substituted dibenzyl diselenides are synthesized in good yields (74–91 %) by SN2 nucleophilic substitution of benzylic trimethylammonium salts and diselenide dianion (Se2−), in situ generated from elemental selenium, under basic conditions. Highly enantiopure dibenzylic diselenides (95–98 % ee) with reverse configurations to their enantioenriched quaternary ammonium salts are obtained, if benzylic quaternary ammonium salts, synthesized from enantiomerically enriched amines, are used.

Current Concepts in Humeral Component Design for Anatomic and Reverse Shoulder Arthroplasty.

The history of humeral component design has evolved from prostheses with relatively long stems and limited anatomic head options to a contemporary platform with short stems and stemless implants with shared instrumentation and the ability to provide optimal shoulder reconstruction for both anatomic and reverse configurations. Contemporary humeral components aim to preserve the bone, but they are potentially subject to malalignment. Modern components are expected to favorably load the humerus and minimize adverse bone reactions. Although there will likely continue to be further refinements in humeral component design, the next frontiers in primary shoulder arthroplasty will revolve around designing an optimal plan, including adequate soft tissue tension and providing computer-assisted tools for the accurate execution of the preoperative plan in the operating room.