Attachment Method Research Articles

Biomechanical Comparison of Three Suspensory Techniques for all Soft Tissue Central Quadriceps Tendon Graft Fixation

PurposeThe purpose of this study was to evaluate three different methods of attachment of continuous loop suspensory cortical preparation of all soft tissue central quad tendon grafts compared to a bone block control for anterior cruciate ligament reconstruction on construct displacement and load to failure.MethodsThirty-two cadaveric central quadriceps tendon (CQT) specimens were harvested, using three clinical techniques for graft fixation: cortical button alone (BTB EB), BTB cortical button with rip-stop suture (BTB RS), and continuous loop cortical button (BTB CL). A control group was also included that consisted of a bone block secured within testing clamps (BTB CON). Specimens were preloaded to 150 N. Tendons were then cyclically loaded between 50 N and 250 N for 1,000 cycles at .5 Hz. Displacement was measured at the point of fixation of the CQT after the 150 N preload, 250 N initial load and every 100th cycle. The specimens were loaded to failure after 1,000 cycles.ResultsThere was a significant increase in displacement from .32 ± .56 mm for the BTB CON to 1.91 ± 1.13 mm for the BTB RS (P = .014) and 3.85 ± 2.32 mm for the BTB CL condition (P = .023). There was no significant increase in displacement for BTB EB (P = .182). Failure occurred for all of the BTB CL and 62.5% of the BTB EB specimens within the first 50 cycles. Twenty-five percent of the BTB CON specimens and 12.5% BTB RS failed at ∼400 and 500 cycles, respectively. Similar failure loads were observed for the BTB CON and the BTB RS (446.4 ± 151.46 N vs 505.74 ± 131.41 N; P = .99) Failure testing was not feasible for the BTB CL and BTB EB preparation methods.ConclusionIn response to cyclic loading, the three all-soft tissue suspensory conditions experienced significantly greater displacement compared to the bone block controls. None of the soft-tissue conditions appeared superior when compared to each other.Clinical RelevanceIt remains unknown which method of soft-tissue suspensory provides optimal fixation. As these autografts become more common, it is essential to evaluate which fixation methods provide superior outcomes

The effect of externally attached archival data loggers on the short-term dispersal behaviour and migration speed of European eel (Anguilla anguilla L.)

BackgroundExternally attached archival data logging tags are increasingly used to unravel migration routes of fish species at sea. Due to the relatively large size of the tags, their application on seaward migrating anguillid eels often forms a challenge in terms of feasibility and impact on the eel’s swimming performance. In this study, we investigated the impact of externally attached pop-up data storage tags (PDSTs) on the departure direction, time spent at the release location and ground speed of European eels (Anguilla anguilla).ResultsWe tagged 66 eels with internal acoustic transmitters of which half of the eels were additionally tagged with externally attached PDSTs. A network of acoustic receivers allowed us to analyse if the dispersal behaviour (i.e. residence time and departure direction) from the release site differed between eels tagged with and without the PDSTs. In addition, we tracked the eels for ca. 83 km in the marine environment and determined their migration speed. The results showed no differences between eels tagged with or without external PDSTs in respect of the external tagging effect on residence time (n = 60), departure direction at the release site (n = 60) or on the migration speed (n = 20).ConclusionsWe conclude that the impact of the PDSTs is minimal on these metrics for at least the first part of the marine migration. While these field-based findings suggest that anguillid eels may be largely unaffected by the applied PDSTs, we recognize that more research is needed in both the field and the laboratory to study the impact of PDSTs and externally attached tags in general on fish swimming performance and energy expenditure. This can help interpret the results from the field, but also aid developing more hydrodynamic tag shapes or improved attachment methods.

The crescendo pulse frequency of shear stress stimulates the endothelialization of bone marrow mesenchymal stem cells on the luminal surface of decellularized scaffold in the bioreactor

ABSTRACT A completely confluent endothelial cell (EC) monolayer is required to maintain proper vascular function in small diameter tissue-engineered vascular graft (TEVG). However, the most effective method for EC attachment to the luminal surface and formation of an entire endothelium layer that works in vitro remains a complicated challenge that requires urgent resolution. Although pulsatile flow has been shown to be better suited for the generation of functional endothelium, the optimal frequency setting is unknown. Several pulsatile flow frequencies were used to implant rat bone mesenchymal stem cells (MSC) into the lumen of decellularized porcine carotid arteries. The endothelium's integrity and cell activity were investigated in order to determine the best pulse frequency settings. The results showed that MSC were maximally preserved and exhibited maximal morphological changes with improved endothelialization performance in response to increased pulse stimulation frequency. Increased pulse frequency stimulation stimulates the expression of mechanoreceptor markers, cytoskeleton reorganization in the direction of blood flow, denser skeletal proteins fibronectin, and stronger intercellular connections when compared to constant pulse frequency stimulation. MSC eventually develops an intact endothelial layer with anti-thrombotic properties on the inner wall of the decellularized tubular lumen. Conclusion: The decellularized vessels retain the three-dimensional structure of the vasculature, have a surface topography suitable for MSC growth, and have good mechanical properties. By increasing the frequency of pulsed stimulation, MSC endothelialize the lumen of the decellularized vasculature. It is expected to have anti-thrombotic and anti-neointimal hyperplasia properties after implantation, ultimately improving the patency of TEVG.

Modeling of the oscillation amplitude of a statically indeterminate flat frame subjected to the impact load with account taken of the contact deformation

Introduction. The article addresses transverse vibrations of a post in a rigidly fixed statically indeterminate flat frame subjected to the falling load, having pre-set mass and pre-impact velocity. The post of a vertical frame has initial curvature affecting the maximum amplitude of transverse vibrations triggered by the impact.
 Materials and methods. In the course of modeling, the frame beam impact takes account of deformations in the contact area to ensure the accuracy of calculations, because otherwise the impact force value will be overestimated. It is assumed that the falling load has the shape of a cylinder featuring a certain length, when the transverse load impact on a frame beam is simulated. The linearization of the relationship between the force and the deformation of cylindrical surfaces is used. The frame post, connected to the beam and the base, is a homogeneous rod rigidly fixed at both ends. Following the load impact on the frame beam, the top end of the post absorbs the initial bending moment and the shear force, whose values depend on the mass the and pre-impact velocity of the load, the beam attachment method, and the ratio between axial moments of inertia in beam and post sections in the plane of the frame. Using the method of initial parameters, the maximum deflection of a perfectly straight and curved post is calculated for different pre-impact velocity values of the load. The maximum deflection was modeled for curved and perfectly straight posts at different pre-impact velocities of a load having the same mass.
 Results. The dependence between the value of maximum deflection of a vertical frame post and the pre-impact velocity of the falling load was obtained.

Optimization of suture attachment for fascia sacral colpopexy using an animal model

The objective of this study is to determine the optimum method of fascial attachment to reduce risk of suture pull-through with failure of the supportive graft. We hypothesized that the risk of suture pull-through will be reduced by

How do exhibitors develop exhibition attachment? Evidence from China

Existing studies on exhibition attachment employ the concept of place attachment and use quantitative methods to explore its influencing factors and outcomes on the premise that exhibition attachment has been formed. However, the theoretical issue of how exhibition attachment is formed has rarely been explored. This study proposed a theoretical framework of the formation mechanism of exhibitors' exhibition attachment through the liminal state. We conducted field observations and in-depth semi-structured interviews of exhibitors attending the Guangzhou (China) International Professional Light and Sound Exhibitions for three years to collect data and employed grounded theory to explore these exhibitors' various changes during the entire exhibition liminal process. Our findings reveal that the formation of exhibition attachment is a complex process, involving four-dimensional changes in time, space, subject behavior, and psychology. In time, exhibitors are in pre-liminal (before the exhibition), liminal (during the exhibition), and post-liminal (after the exhibition) phases. Accordingly, the spatial perception of the exhibition evolved from a physical to an interactive space, and thereafter to an emotional space. By integrating the network platform constructed by the organizers and acquiring experience value, exhibitors can identify with and ultimately develop their attachment to the exhibition. Their psychological perception of the exhibition gradually changed from a functional business place to an important event that stimulates their personal and corporate growth. This study provides empirical evidence for the nature of liminality and expands our understanding of exhibition attachment. In addition, the transformation of brand identity before exhibition into exhibition identity after exhibition provides theoretical reference and practical guidance for the exhibition's organization and management.

The Impact of Housing Densification on Shading Potential of Open Spaces: A Case Study

This study discusses housing densification as a sustainable housing strategy. Furthermore, it investigates how housing densification can improve the shading performance of open spaces with respect to row-house typology. The analysis considers a real-time case study of linear courtyards enclosed by row houses. Urban analysis was followed by a numerical shading analysis to examine the impact of housing attachment method (aligned or stepped) on courtyard shading potential. Row houses were found to be an acceptable housing densification solution in Saudi Arabia, with well-integrated open spaces. The stepped-attached housing pattern showed a higher potential for urban shading (by ~55% with an east–west orientation of row houses) than that of the aligned–attached pattern. In addition, the stepped-attached housing pattern improved the visual quality and created a serial visual effect. This study recommends the promotion of compact housing patterns in Saudi Arabia to reduce the rapidly increasing domestic electrical-energy demand and improve urban shading. Housing densification is considered as an effective passive design and planning strategy for this purpose.

Evaluation of six methods for external attachment of electronic tags to fish: assessment of tag retention, growth and fish welfare.

External attachment of electronic tags has been increasingly used in fish studies. Many researchers have used ad hoc attachment methods and provided little or no validation for the assumption that tagging itself does not bias animal behaviour or survival. The authors compared six previously published methods for externally attaching acoustic transmitters to fish in a tank holding experiment with black sea bass Centropristis striata (L.). They tracked tag retention, fish growth and external trauma (as a measure of fish welfare) for 60 days. For each of these metrics, the results showed a wide range of responses among tagging treatments. A simple attachment method using a spaghetti tag passed through the dorsal musculature of the fish and tied to the end cap of the transmitter emerged as the preferred option based on high retention, no impact on growth and relatively low detriment to fish welfare. Future field studies using external electronic tagging should consider tag‐related effects that could compromise results when selecting a method for tag attachment.

Telemetry tails: a practical method for attaching animal-borne devices to small vertebrates in the field

Context Continued miniaturisation of tracking technology increases its utility in animal applications. However, species morphology often dictates the type of animal-borne device (ABD) that can be used, and how it is attached. The morphology of species within Peramelemorphia preclude them from the standard collar attachment of ABDs for terrestrial mammals. Aims This paper describes a method for the tail-mount attachment of ABDs, and deployment results for Peramelemorphia across arid, semi-arid and temperate Australia to (a) test the performance of attachments and ABDs in the field and (b) discuss the animal welfare considerations for this attachment method. Methods Tail-mount attachment of ABDs were field-tested on a total of 80 greater bilbies (Macrotis lagotis), and 14 long-nosed bandicoots (Perameles nasuta). Key results Time to natural detachment (TTND) was between 2 and 52 days, with 65.74% (142 of 216) remaining on until manual removal. For ABDs that were manually removed, attachments were retained for up to 94 days. The method used for tail-mount attachment of ABDs to long-nosed bandicoots resulted in significantly shorter TTND compared with the method used for bilbies, and environmental factors (high temperatures and rainfall) had a negative effect on TTND. Tail-mount attached global positioning system (GPS) sensors collected large quantities of accurate data, with a maximum fix success rate of 83.38%. Damage to GPS (antenna breakage and water ingress) during deployment, however, impacted performance. In environments with frequent rainfall and waterlogged soils, the tape on a small proportion (6.25%) of (n = 192) attachments to bilbies caused tail injury. All injuries were resolvable, with most requiring minimal to no veterinary intervention. Key conclusions Attachment longevity can be affected by how the ABD is mounted to the tail, the species and the deployment environment. The environment can also affect which adhesive tapes are suitable for ABD attachment. However, this method is highly modifiable, practical for field application and can have long retention times relative to other temporary methods. Implications This ABD tail-mount attachment method adds another tool to the telemetry tool-kit, with all the benefits of a low-tech, low-cost, passive drop-off type attachment. This method has demonstrated practicality for Peramelemorphia, with potential application to other suitable small vertebrates.

The effect of different mouth washes on metallic ions release from silver-soldered and laser-welded orthodontic attachments. A comparative in vitro study

To compare the effect of different mouth washes on metallic ions release from silver-soldered and laser-welded orthodontic attachments. In this comparative in vitro study, 32 samples of molar bands without attachments were used. Sixteen samples were silver soldered to stainless steel (SS) wire and 16 samples were laser welded using laser welding device to SS wire. Each group samples were divided into four test groups and submerged in solution containing sodium fluoride (NaF), NaF + alcohol (NaF + alcohol), Chlorhexidine (CHX), and artificial saliva (AS). Samples were shaken for 24 h with an agitation rate of 60 rpm. One sample from each group was selected to study the morphologic changes on their surfaces through scanning electron microscopy (SEM), and remaining samples were studied for metal ions released and dissolved in the solutions using spectrometry. The metal ions release values of two different attachment methods in three different mouth washes and AS group were compared using the unpaired t-test. A two-way analysis of variance was used to identify the significant differences between the two types of orthodontic attachments immersed in four different types of solutions. P < 0.05 was defined to be set significant for all tests. Level of metal ions released from the samples of silver soldering was higher than from laser welding. The lowest amounts of metal ions were released in CHX while highest in NaF + alcohol. The SEM images were in accordance with these findings. Laser welding should be preferred over silver soldering for the construction of orthodontic appliances. CHX containing mouthwashes such as Hexidine can be prescribed for the patients undergoing orthodontic treatment. More in vivo experiments will determine whether the levels of dissolved nickel ions can reach the toxic or sub-toxic concentrations or not.

Confirmed feasibility of a satellite tracker attachment method on small juvenile hawksbill turtles Eretmochelys imbricata

Satellite trackers can be used for studying sea turtle movement, illuminating their migrations and behaviours. However, many studies have focused on adult turtles, with uneven species representation, despite the importance of understanding movement and habitat use of turtles at all life-stages. Furthermore, few publications detail successful satellite tracker attachment methods, particularly for juveniles. Smaller-sized juvenile sea turtles often have an irregularly shaped carapace and are fast growing, rendering the attachment of rigid trackers in a safe and durable manner challenging. Juvenile hawksbill turtles’ specific carapace shape and imbricated scute arrangement further complicate satellite tracker attachment compared to juveniles of other turtle species. This study’s objective was to confirm the feasibility of an attachment method that would allow small-sized juvenile hawksbill turtles (~267-345 mm curved carapace length) to continue growing, without tracker loss or damage to underlying scutes. Replica trackers were made of resin (simulating Wildlife Computer Spot-387 trackers), and attached with epoxy, silicone and neoprene, using a technique modified from those used on neonate loggerheads and Kemp’s ridleys. Throughout the study (3.5 mo), replica trackers remained attached, the turtles grew up to 114% heavier and 25% longer, and all turtles appeared clinically healthy and active. Furthermore, all scutes were undamaged after tracker removal. As a critically endangered species, the paucity of data on hawksbill turtles, and specifically juveniles, can hinder evidence-based management decision-making. The improved ability to satellite track juvenile hawksbills can, therefore, help better our understanding of their ecology and inform management and conservation practices for this species.

Enhancement of Activity for Peroxidase-Mimicking DNAzyme by Covalent Attachment of Hemin to G-Quadruplex-Forming Oligonucleotide Using Click Chemistry.

Peroxidase-mimicking DNAzymes are used in the development of new bioanalytical assays due to their advantages like thermal stability, simple synthesis and purification, and ability to hybridize with the complementary strand of nucleic acid. Here, we describe the method of covalent attachment of hemin to DNA oligonucleotide using click chemistry that allows good yield (60-70%) of the final conjugate product. The activity of obtained DNAzymes is monitored using chromogenic and fluorogenic substrates.

Нековалентные структуры отрицательных ионов, образующиеся при диссоциативном захвате электронов молекулами

The method of dissociative electron attachment (DEA) spectroscopy was used to study the attachment of electrons to 1-chloronaphthalene molecules. It has been established that the dominant channel for the decay of molecular ions is the formation of Clˉ ions in three resonances at 0.7, 1.5, and 3.0 eV. Ions [M-H]ˉ and [M-Cl]ˉ are observed at energies from 3.5 to 8.5 eV and have two to three orders of magnitude lower formation cross sections. Long-lived molecular ions were not registered. Calculations in the DFT CAM B3LYP/6-311+G(d,p) approximation predict the presence of six stable anionic structures in which the chlorine anion is coordinated to the neutral residue via noncovalent H–Clˉ–H bonds. The electron affinity of the most stable of these structures coincides with the experimentally measured value EAa=0.2771±0.003 eV. These results agree with the previously obtained data on the DEA of molecules of bromine-substituted biphenyls, naphthalenes, and anthracenes and confirm the existence of anionic structures with non-covalent H–Hal–H bonds. Such non-covalent anion structures should be extremely reactive, which makes them promising for the synthesis of self-assembling hydrocarbon nanomembranes.

Non-covalent structures of negative ions formed during the dissociative capture of electrons by molecules

The method of dissociative electron attachment (DEA) spectroscopy was used to study the attachment of electrons to 1-chloronaphthalene molecules. It has been established that the dominant channel for the decay of molecular ions is the formation of Cl- ions in three resonances at 0.7, 1.5, and 3.0 eV. Ions [M-H]- and [M-Cl]- are observed at energies from 3.5 to 8.5 eV and have two to three orders of magnitude lower formation cross sections. Long-lived molecular ions were not registered. Calculations in the DFT CAM B3LYP/6-311+G(d,p) approximation predict the presence of six stable anionic structures in which the chlorine anion is coordinated to the neutral residue via noncovalent H-Cl^--H bonds. The electron affinity of the most stable of these structures coincides with the experimentally measured value EA_a=0.2771±0.003 eV. These results agree with the previously obtained data on the DEA of molecules of bromine-substituted biphenyls, naphthalenes, and anthracenes and confirm the existence of anionic structures with non-covalent H-Hal-H bonds. Such non-covalent anion structures should be extremely reactive, which makes them promising for the synthesis of self-assembling hydrocarbon nanomembranes. Keywords: Attachment of electrons to molecules, electron affinity, potential surface, DFT calculations.

Adeno-Associated Viral Vector Immobilization and Local Delivery from Bare Metal Surfaces.

Spatially and temporally controlled delivery of biologicals, including gene vectors, represents an unmet need for regenerative medicine and gene therapy applications. Here we describe a method of reversible attachment of serotype 2 adeno-associated viral vectors (AAV2) to metal surfaces. This technique enables localized delivery of the vector to the target cell population in vitro and in vivo with the subsequent effective transduction of cells adjacent to the metal substrate. The underlying bioengineering approach employs coordination chemistry between the bisphosphonic groups of polyallylamine bisphosphonates and the metal atoms on the surface of metallic samples. Formation of a stable polybisphosphonate monolayer with plentiful allyl-derived amines allows for further chemical modification to consecutively append thiol-modified protein G, an anti-AAV2 antibody, and AAV2 particles. Herein we present a detailed protocols for the metal substrate modification, for the visualization of the metal surface-immobilized vector using direct and indirect fluorescent AAV2 labeling and scanning electron microscopy, for quantification of the surface-immobilized vector load with RT-PCR, and for the localized vector transduction in vitro and in vivo.

ANALYSIS OF METHODS OF ATTACHMENT OF THE TURBOFAN ON THE AIRCRAFT WING AND POSSIBLE WAYS TO SOLVING MASS PROBLEMS

ANALYSIS OF METHODS OF ATTACHMENT OF THE TURBOFAN ON THE AIRCRAFT WING AND POSSIBLE WAYS TO SOLVING MASS PROBLEMS

Investigation of assault flags from the collection of the Military-Historical Museum of Artillery, Engineer and Signal Corps

In the article author conducts research of the assault flags from the collection of Military Historical Museum of Artillery, Engineer and Signal Corps. They were planted on the liberated by the Soviet Army cities. At the beginning of the article the reader is informed about the meaning of the basic concepts. There aren’t differences between знамя and флаг in vexillology. Therefore, several definitions of Russian researchers were considered. Then in the article are stated that this group are flags, as it symbolizes the whole state — the Soviet Union. The author emphasizes that the tradition of planting assault flags over liberated cities appeared during the radical turn of 1942–1943, and at the same time flags began to be transferred to museums for storage. In the Artillery Historical Museum they began to arrive from 1943. In addition, their appearance wasn’t regulated. Therefore, in the article the problem of similar and different characteristics is raised. At the semiotic level, all flags carry a single code, being a symbol of liberation, victory of the Soviet Union and friendly countries over the German invaders. At the material level, due to the lack of clear regulation of the appearance, each flag has its own individual features: size, shape, presence or absence of images and inscriptions, methods of attachment to the flagpole, the context of their appearance. In conclusion the potential for reflecting the theme of the Great Patriotic War and the memory of the people in exposition and exhibition projects is evaluated.

Development of eClaim system for private indemnity health insurance in South Korea: Compatibility and interoperability.

South Korea has the mandatory National Health Insurance (NHI) and supplemental Private Indemnity Health Insurance (PIHI). According to the Financial Supervisory Service, the share of the population with PIHI increased to 66% in 2018 due to the financial burden. However, since the traditional PIHI claim workflow is based on the paper attachment method, it is a big burden to every stakeholder and limits the usability and accessibility of the claims data. To improve the traditional PIHI claim workflow, we developed the electronic claim (eClaim) service for the PIHI in Korea. We also applied the HL7® (Health Level Seven) FHIR® (Fast Healthcare Interoperability Resources) standard to ensure interoperability of the claims data. The proposed eClaim Service has been launched in 2017. It has been increased from 8155 in the first half of 2018 to 114,087 in the second half of 2020. Currently, 60 healthcare providers and 22 payers participated in this service. In this study, we proposed an eClaim workflow and service to improve the legacy system. The proposed method can be helpful to other entities planning for their own health insurance system and also applied to various practical purposes including value-based care, automated claim review, and clinical research.

Microwave-assisted surface attachment of aluminium ions on in situ diluted titanium-doped hematite photoanodes for efficient photoelectrochemical water-splitting

Al/Ti co-doping was performed through an effective microwave-assisted surface attachment method. The synergistic effect of Al/Ti co-doping and an Al2O3 passivation layer significantly boosts the PEC performance in the Al(5 mM)/Ti(4%):Fe2O3 photoanode.

An evaluation of transmitter effects on adult and juvenile Common Terns using leg-loop harness attachments

Marking birds with transmitters allows for the collection of data that are critical for fully understanding avian life history, but researchers must also be confident that performing such studies is as safe as possible for transmittered individuals. While much could be learned from tracking juveniles across dependency periods and first migration, doing so would require a harness-based attachment method which has not been evaluated on any species of juvenile tern. Therefore, we monitored the reproductive success and behavior of adult Common Terns (<em>Sterna hirundo</em>) and the growth and behavior of juvenile Common Terns after attaching transmitters to adults and juveniles with leg-loop harnesses made of elastic cord. We found that transmittered adults had similar reproductive success to untransmittered controls (hatching success for nests of transmittered adults = 0.553; nests of control adults = 0.665). Transmittered adults also expressed minimal behavioral differences from untransmittered controls when the groups were compared via paired treatment-control nest observations along with observations away from the nest. Transmittered juveniles had similar fledging success and growth rates to untransmittered control juveniles (fledging success for transmittered juveniles = 0.766; control juveniles = 0.817). Transmittered juveniles exhibited slight differences in behavior from controls, with increased rates of preening, although these differences did not appear to be detrimental. Finally, monitoring efforts during the breeding season following transmitter deployment found no difference in the return rate, nesting attempt rate, or hatching success rate based on treatment (P > 0.05). However, despite evidence of an individual retaining its transmitter into fall migration, no individuals retained their transmitters when resighted the following breeding season. While our results show that leg-loop harnesses made of elastic cord present a potential option for transmitter attachment to both adult and juvenile Common Terns, additional testing could provide further insight into potential long-term impacts.