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1.
Cell ; 179(3): 619-631.e15, 2019 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-31626768

RESUMEN

DNA replication in eukaryotes generates DNA supercoiling, which may intertwine (braid) daughter chromatin fibers to form precatenanes, posing topological challenges during chromosome segregation. The mechanisms that limit precatenane formation remain unclear. By making direct torque measurements, we demonstrate that the intrinsic mechanical properties of chromatin play a fundamental role in dictating precatenane formation and regulating chromatin topology. Whereas a single chromatin fiber is torsionally soft, a braided fiber is torsionally stiff, indicating that supercoiling on chromatin substrates is preferentially directed in front of the fork during replication. We further show that topoisomerase II relaxation displays a strong preference for a single chromatin fiber over a braided fiber. These results suggest a synergistic coordination-the mechanical properties of chromatin inherently suppress precatenane formation during replication elongation by driving DNA supercoiling ahead of the fork, where supercoiling is more efficiently removed by topoisomerase II. VIDEO ABSTRACT.


Asunto(s)
Cromatina/química , ADN-Topoisomerasas de Tipo II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Torque , Cromatina/metabolismo , Replicación del ADN , ADN Superhelicoidal/química , Células HeLa , Humanos , Pinzas Ópticas , Saccharomyces cerevisiae
2.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-34417290

RESUMEN

Braiding of topological structures in complex matter fields provides a robust framework for encoding and processing information, and it has been extensively studied in the context of topological quantum computation. In living systems, topological defects are crucial for the localization and organization of biochemical signaling waves, but their braiding dynamics remain unexplored. Here, we show that the spiral wave cores, which organize the Rho-GTP protein signaling dynamics and force generation on the membrane of starfish egg cells, undergo spontaneous braiding dynamics. Experimentally measured world line braiding exponents and topological entropy correlate with cellular activity and agree with predictions from a generic field theory. Our analysis further reveals the creation and annihilation of virtual quasi-particle excitations during defect scattering events, suggesting phenomenological parallels between quantum and living matter.


Asunto(s)
Algoritmos , Membrana Celular/metabolismo , Oocitos/metabolismo , Teoría Cuántica , Estrellas de Mar/fisiología , Proteínas de Unión al GTP rho/metabolismo , Animales , Oocitos/citología
3.
Nano Lett ; 23(10): 4669-4674, 2023 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-36917692

RESUMEN

The positions of Abrikosov vortices have long been considered as means to encode classical information. Although it is possible to move individual vortices using local probes, the challenge of scalable on-chip vortex-control remains outstanding, especially when considering the demands of controlling multiple vortices. Realization of vortex logic requires means to shuttle vortices reliably between engineered pinning potentials, while concomitantly keeping all other vortices fixed. We demonstrate such capabilities using Nb loops patterned below a NbSe2 layer. SQUID-on-Tip (SOT) microscopy reveals that the loops localize vortices in designated sites to a precision better than 100 nm; they realize "push" and "pull" operations of vortices as far as 3 µm. Successive application of such operations shuttles a vortex between adjacent loops. Our results may be used as means to integrate vortices in future quantum circuitry. Strikingly, we demonstrate a winding operation, paving the way for future topological quantum computing and simulations.

4.
Angew Chem Int Ed Engl ; 63(7): e202318401, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38153195

RESUMEN

Zero area compressibility (ZAC) is an extremely rare mechanical response that exhibits an invariant two-dimensional size under hydrostatic pressure. All known ZAC materials are constructed from units in two dimensions as a whole. Here, we propose another strategy to obtain the ZAC by microscopically orthogonal-braiding one-dimensional zero compressibility strips. Accordingly, ZAC is identified in a copper-based compound with a planar [CuO4 ] unit, Cu2 GeO4 , that possesses an area compressibility as low as 1.58(26) TPa-1 over a wide pressure range from ≈0 GPa to 21.22 GPa. Based on our structural analysis, the subtle counterbalance between the shrinkage of [CuO4 ] and the expansion effect from the increase in the [CuO4 ]-[CuO4 ] dihedral angle attributes to the ZAC response. High-pressure Raman spectroscopy, in combination with first-principles calculations, shows that the electron transfer from in-plane bonding dx 2 -y 2 to out-of-plane nonbonding dz 2 orbitals within copper atoms causes the counterintuitive extension of the [CuO4 ]-[CuO4 ] dihedral angle under pressure. Our study provides an understanding on the pressure-induced structural evolution of copper-based oxides at an electronic level and facilitates a new avenue for the exploration of high-dimensional anomalous mechanical materials.

5.
Angew Chem Int Ed Engl ; 62(24): e202303616, 2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-37040128

RESUMEN

Fiber lithium-ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium-ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi-axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes. In comparison to typical solid copper wires, the braided fiber current collector hosted 139 % graphite with only 1/3 mass. The fiber graphite anode with braided current collector delivered high specific capacity of 170 mAh g-1 based on the overall electrode weight, which was 2 times higher than that of its counterpart solid copper wire. The resulting fiber battery showed high energy density of 62 Wh kg-1 .

6.
Gen Dent ; 70(1): 35-39, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34978988

RESUMEN

Successful management of separated endodontic instruments is difficult, but several techniques are available for the retrieval of a separated instrument (SI). An appropriate treatment plan depends on various factors, including the anatomy and location of the tooth; the size, type, and location of the SI; and the skill of the clinician. However, the selection of the most appropriate management technique based on these factors can be a challenging decision that directly influences the success of the procedure. This article presents 4 symptomatic cases of SIs managed with various modalities as well as 1-year clinical and radiographic follow-up results. The management techniques applied in these cases included the use of ultrasonic tips, the wire loop method, safe-sided H-files, the braiding technique, and bypassing of the file. The medical history of the patients was noncontributory except for a single patient who had type 2 diabetes mellitus, which might have delayed healing. After instrument retrieval, the patients were evaluated clinically for relief of signs and symptoms as well as for their responses to various tests such as percussion, palpation, and tooth mobility. Radiographic evaluation at the 12-month follow-up was used to determine the periapical index. The clinical and radiographic results and patient-reported outcomes were satisfactory in all cases. The 4 cases presented demonstrate that the keys to successful management of an SI are understanding the factors that influence the case and selecting an appropriate therapeutic technique.


Asunto(s)
Diabetes Mellitus Tipo 2 , Humanos , Preparación del Conducto Radicular
7.
Artif Organs ; 45(3): 278-288, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32969519

RESUMEN

The damage caused to the fabric of endovascular stent-grafts most often occurs at the contact zones between the fabrics where they are attached to the apices of Z-shaped stents as a result of normal physiologic pulsatile movement within angulated vessels in vivo. Although design improvements were made over the years, the risks were not fully eliminated even with the newer M-shaped stent reconfiguration. In this study, we proposed to create and manufacture a novel fabric for stent-grafts with specifically designed reinforced zones to enhance resistance to fabric abrasion. These reinforced zones are set at the vicinity of the apices of the Z-shaped stents and between two adjacent Z-shaped stents where folding and pleating are commonly observed to occur in angulated vessels. Three innovative weaving structures with two different types of yarns and two controls were designed and prepared. Two commonly used commercial devices supported, respectively, with ringed stents, and Z-shaped stents were selected as the references for comparison. Textile structures including thickness, water permeability, mechanical properties, (more specifically tensile and bursting stress, as well as fatigue simulation) were tested on all fabrics. Compared to commercially available plain weaves, the fabrics with locally reinforced zones showed improved mechanical characteristics and fatigue resistant properties. A fabric designed with specifically reinforced zones has now clearly been shown to effectively reduce the abrasion caused by the apices of Z-shaped stents. However, further optimization may still be possible.


Asunto(s)
Implantación de Prótesis Vascular/efectos adversos , Endofuga/prevención & control , Procedimientos Endovasculares/efectos adversos , Diseño de Prótesis , Textiles , Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/instrumentación , Endofuga/etiología , Procedimientos Endovasculares/instrumentación , Ensayo de Materiales , Stents/efectos adversos
8.
Proc Natl Acad Sci U S A ; 115(19): 4869-4874, 2018 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-29686070

RESUMEN

Fluids may store and manipulate information, enabling complex applications ranging from digital logic gates to algorithmic self-assembly. While controllable hydrodynamic chaos has previously been observed in viscous fluids and harnessed for efficient mixing, its application to the manipulation of digital information has been sparsely investigated. We show that chaotic stirring of a viscous fluid naturally produces a characteristic signature of the stirring process in the arrangement of particles in the fluid, and that this signature directly satisfies the requirements for a cryptographic hash function. This includes strong divergence between similar stirring protocols' hashes and avoidance of collisions (identical hashes from distinct stirs), which are facilitated by noninvertibility and a broad chaotic attractor that samples many points in the fluid domain. The hashing ability of the chaotic fluidic map implicates several unexpected mechanisms, including incomplete mixing at short time scales that produces a hyperuniform hash distribution. We investigate the dynamics of hashing using interparticle winding statistics, and find that hashing starts with large-scale winding of kinetically disjoint regions of the chaotic attractor, which gradually gives way to smaller scale braiding of single-particle trajectories. In addition to providing a physically motivated approach to implementing and analyzing deterministic chaotic maps for cryptographic applications, we anticipate that our approach has applications in microfluidic proof-of-work systems and characterizing large-scale turbulent flows from sparse tracer data.

9.
Int J Cosmet Sci ; 43(3): 321-331, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33605448

RESUMEN

BACKGROUND: Afro hair breakage is most commonly attributed to grooming practices such as braiding, hair extensions and weaves, both for chemically treated hair and natural Afro hair. These grooming practices are also frequently associated with traction alopecia in clinical studies. However, there is little to no quantitative scientific data on the surface and internal hair fibre damage caused by grooming, including combing, on Afro hair. METHODS: Qualitative and quantitative techniques such as scanning electron microscopy, cuticle cohesion and tensile testing were used to determine the effects of frequent braiding on the integrity of female Afro hair in 15 frequent braiders and 15 occasional braiders (control group) in Johannesburg, South Africa. Frequent braiders were women who braided more than 8 times per year, while occasional braiders typically limit braiding to only twice 2 per year. The severity of traction alopecia was quantified in both groups using the standard Marginal Traction Alopecia Scoring system. Surface damage on naturally curly Afro hair, that was combed but not braided, was assessed as another hairstyle option. RESULTS: All measurements showed a relationship between surface and internal hair fibre damage and braiding frequency. Frequent braiders had thinner hair, with more cuticle damage as shown by SEM and cuticle cohesion assessments. Their hair fibres were also significantly weaker (p < 0.05), as shown by the tensile testing. In addition, they also had higher traction alopecia severity scores. In the combing impact assessment, a linear trend was observed between surface hair fibre damage and the number of combing strokes. Cuticle damage from 480 combing strokes was more severe than that from frequent braiding. CONCLUSION: Frequent braiding and combing damage natural Afro hair. Quantification of damage caused by different grooming practices identifies a need to develop products that could help mitigate specific hair damage associated with grooming practices. The degree of damage and subsequent hair loss could also be minimized by education on best braiding practices to protect the hair fibre and avoid hair follicle miniaturization caused by high traction hairstyles.


CONTEXTE: La casse des cheveux d'origine Africaine est le plus souvent associées à des pratiques cosmétiques telles que le tressage et les extensions de cheveux, à la fois pour les cheveux traités chimiquement et les cheveux naturels. Ces pratiques cosmétiques sont également fréquemment associées à une alopécie de traction, comme le relatent les études cliniques. Cependant, il existe peu ou pas de données scientifiques quantitatives sur l'impact de ce type de pratiques, y compris le peignage, sur les dommages internes et de surface des cheveux d'origine africaine. MÉTHODES: Des techniques qualitatives et quantitatives, comme la microscopie électronique à balayage (MEB), la cohésion cuticulaire et des tests de traction, ont été utilisés pour déterminer les effets du tressage sur l'intégrité des cheveux de deux groupes de 15 femmes Africaines (à Johannesburg, Afrique du Sud) : un premier groupe de femmes pratiquant un tressage fréquent et un autre groupe un tressage occasionnel. Le groupe des tresseurs fréquents correspond à des femmes qui pratiquent le tressage plus de 8 fois par an, tandis que les tresseurs occasionnels limitent généralement le tressage à seulement deux fois par an. La gravité de l'alopécie de traction a été également quantifiée dans les deux groupes à l'aide du système standard de notation de l'alopécie tractionnelle. Parallèlement, à titre de comparaison, les dommages de surface ont été également évalués sur des cheveux d'origine Africaine naturellement bouclés, non tressés, mais qui ont subi un peignage répété. RÉSULTATS: Toutes les mesures ont montré une relation entre les dommages de surface et internes de la fibre et la fréquence de tressage. Les tresseurs fréquents ont des cheveux plus fins, avec un endommagement plus important de la cuticule, comme le montrent les évaluations MEB et la cohésion cuticulaire. Les cheveux sont également significativement plus fragiles (p <0,05), comme le montrent les tests de traction. De plus, ces femmes ont également des scores d'alopécie de traction plus élevés. Dans le cas spécifique du peignage répété, une tendance linéaire a été observée entre les dommages en surface de la fibre capillaire et le nombre de coups de peigne. On peut également noter que l'endommagement de la cuticule causé par 480 coups de peigne est plus important que celui causé par des tressages fréquents. CONCLUSION: Les tressages et peignages fréquents endommagent les cheveux naturels d'origine Africaine. La quantification des dommages causés par différentes pratiques cosmétiques met en évidence le besoin de développer des produits qui pourraient aider à atténuer les dommages liés à des pratiques spécifiques. Le niveau de dommage et la perte de cheveux pourraient également être minimisés par un apprentissage de meilleures pratiques de tressage pour protéger la fibre et éviter la diminution des follicules pileux causée par des coiffures qui entrainent un forte traction sur la fibre.


Asunto(s)
Población Negra , Cabello , Alopecia/etiología , Alopecia/patología , Folículo Piloso/ultraestructura , Humanos , Microscopía Electrónica de Rastreo , Índice de Severidad de la Enfermedad
10.
Environ Monit Assess ; 193(2): 96, 2021 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-33511428

RESUMEN

Earth observation data provides an exceptional opportunity to study the temporal dynamics of large rivers. The availability of spatially continuous, synoptic and temporally repetitive satellite data allows the reconstruction of historical dynamics of large rivers along with the identification of the causal factors. An absolute paucity of information on the effect of hydrogeomorphic processes on the dynamics of the Upper Ganga River (UGR), especially upon its entry in the plains, motivated this research. This study aims to analyse morphological changes in the river channel, map temporal changes in the land use/land cover (LULC) within the riverscape and thereby understand the landscape dynamics in the UGR (Haridwar to Narora) during 1993-2017 by means of earth observation data. The analysis showed that the river remains straight with a sinuosity index of < 1; however, the braiding increased considerably (from 3.79 to 4.53). Erosion being more prominent on the left bank in comparison to the right bank with 85.89 km2 eroded on the left bank in comparison to 59.21 km2 eroded along the right bank. Riverine landscape has been observed to have a higher rate of accretion in comparison to erosion (8.09 km2 yr-1 and 6.04 km2 yr-1, respectively). Morphological change has brought a transition in the land use patterns with marked variation in vegetation and agriculture along with built-up. Significant changes in the composition of the LULC are largely due to the manifold increase in the agriculture extent (≈ 12 times), built-up (5 times) and the decrease in vegetation cover from 43.9% in 1993 to just 10.94% in 2017.


Asunto(s)
Monitoreo del Ambiente , Ríos , Agricultura , India
11.
Nanomedicine ; 24: 102131, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31778808

RESUMEN

In this work, the effects of carbon nanofiber (CNF) dispersed poly-ε-caprolactone (PCL) nanocomposite coatings and biomolecules functionalization on silk fibroin based conducting braided nerve conduits were studied for enhancing Neuro 2a cellular activities. A unique combination of biomolecules (UCM) and varying concentrations of CNF (5, 7.5, 10% w/w) were dispersed in 10% (w/v) PCL solution for coating on degummed silk threads. The coated silk threads were braided to develop the scaffold structure. As the concentration of CNF increased in the coating, the electrical impedance decreased up to 400 Ω indicating better conductivity. The tensile and dynamic mechanical property analysis showed better mechanical properties in CNF coated samples. In vitro cytocompatibility analysis proved the non-toxicity of the developed braided conduits. Cell attachment, growth and proliferation were significantly enhanced on the biomolecule functionalized nanocomposite coated silk braided structure, exhibiting their potential for peripheral nerve regeneration and recovery.


Asunto(s)
Caproatos/química , Carbono/química , Fibroínas/química , Lactonas/química , Nanocompuestos/química , Nanofibras/química , Seda/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Línea Celular Tumoral , Proliferación Celular/fisiología , Humanos , Microscopía Confocal
12.
Water Resour Res ; 52(8): 6621-6642, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27708477

RESUMEN

Numerical morphological modeling of braided rivers, using a physics-based approach, is increasingly used as a technique to explore controls on river pattern and, from an applied perspective, to simulate the impact of channel modifications. This paper assesses a depth-averaged nonuniform sediment model (Delft3D) to predict the morphodynamics of a 2.5 km long reach of the braided Rees River, New Zealand, during a single high-flow event. Evaluation of model performance primarily focused upon using high-resolution Digital Elevation Models (DEMs) of Difference, derived from a fusion of terrestrial laser scanning and optical empirical bathymetric mapping, to compare observed and predicted patterns of erosion and deposition and reach-scale sediment budgets. For the calibrated model, this was supplemented with planform metrics (e.g., braiding intensity). Extensive sensitivity analysis of model functions and parameters was executed, including consideration of numerical scheme for bed load component calculations, hydraulics, bed composition, bed load transport and bed slope effects, bank erosion, and frequency of calculations. Total predicted volumes of erosion and deposition corresponded well to those observed. The difference between predicted and observed volumes of erosion was less than the factor of two that characterizes the accuracy of the Gaeuman et al. bed load transport formula. Grain size distributions were best represented using two φ intervals. For unsteady flows, results were sensitive to the morphological time scale factor. The approach of comparing observed and predicted morphological sediment budgets shows the value of using natural experiment data sets for model testing. Sensitivity results are transferable to guide Delft3D applications to other rivers.

13.
J Phys Condens Matter ; 36(34)2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38729174

RESUMEN

Resonant exchange of the chiral Majorana fermions (MFs) that is coupled to two parallel Majorana zero modes (MZMs) or two parallel quantum dots (QDs) is investigated. We find that, in the two QDs coupling case, the resonant exchange for the chiral MFs is analogous to that in the MZM coupling case. We further propose a circuit based on topological superconductor, which is formed by the proximity coupling of a quantum anomalous Hall insulator and a s-wave superconductor, to observe the resonant exchange of chiral MFs pairs. The numerical calculations show that the resonant transmission of the chiral MFs can be adjusted by varying the coupling parameters at superconductor phase differenceΔφ=π. It is particularly noteworthy that, by only modulating the coupling strength between the two QDs, the resonant exchange may be switched on or off. By adding another MZM, the non-Abelian braiding like operation can be realized. Therefore, our design scheme may provide another way for non-Abelian braiding operation of MFs and the findings may have potential application value in the realization of topological quantum computers.

14.
Cureus ; 16(6): e62322, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39006612

RESUMEN

Subgaleal fluid collection is a rare phenomenon of scalp swelling among young infants and, in many cases, adolescents. As fluid accumulates in the subgaleal space, it presents as a soft, ill-defined, fluctuant, mobile swelling not limited to suture lines. This condition is associated with vacuum-assisted devices and forceps during delivery in infancy. Beyond infancy, this condition can be seen spontaneously or, most commonly, after minor head traumas. Such minor traumas that have been reported in recent years include hair pulling or hair braiding. Early recognition of this condition and its complications is essential for appropriate treatment and management. In this case report, we highlight the importance of subgaleal fluid collection being considered a differential diagnosis of headaches, particularly in children and adolescents who present with excessive hair pulling or hair braiding.

15.
Polymers (Basel) ; 16(4)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38399866

RESUMEN

The use of tissue engineering to address the shortcomings of current procedures for tendons and ligaments is promising, but it requires a suitable scaffold that meets various mechanical, degradation-related, scalability-related, and biological requirements. Macroporous textile scaffolds made from appropriate fiber material have the potential to fulfill the first three requirements. This study aimed to investigate the biocompatibility, sterilizability, and functionalizability of a multilayer braided scaffold. These macroporous scaffolds with dimensions similar to those of the human anterior cruciate ligament consist of fibers with appropriate tensile strength and degradation behavior melt-spun from Polycaprolactone (PCL). Two different cross-sectional geometries resulting in significantly different specific surface areas and morphologies were used at the fiber level, and a Chitosan-graft-PCL (CS-g-PCL) surface modification was applied to the melt-spun substrates for the first time. All scaffolds elicited a positive cell response, and the CS-g-PCL modification provided a platform for incorporating functionalization agents such as drug delivery systems for growth factors, which were successfully released in therapeutically effective quantities. The fiber geometry was found to be a variable that could be manipulated to control the amount released. Therefore, scaled, surface-modified textile scaffolds are a versatile technology that can successfully address the complex requirements of tissue engineering for ligaments and tendons, as well as other structures.

16.
Polymers (Basel) ; 16(16)2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39204570

RESUMEN

Injuries to tendons and ligaments are highly prevalent in the musculoskeletal system. Current treatments involve autologous transplants with limited availability and donor site morbidity. Tissue engineering offers a new approach through temporary load-bearing scaffolds. These scaffolds have to fulfill numerous requirements, the majority of which can be met using braiding combined with high-strength polycaprolactone (PCL) fibers. Considering regulatory requirements, several medical-grade PCL materials were assessed regarding their mechanical, degradational and cell biological properties. In the course of the investigation, an excellent fiber tensile strength of up to 850 MPa was achieved. The fibers were braided into multilayer scaffolds and scaled to match the human ACL. These were characterized regarding their morphology and their mechanical and degradational properties. Two strategies were followed to provide biological cues: (a) applying a chitosan-graft-PCL surface modification and (b) using non-circular fiber morphologies as topographical stimuli. Cell vitality assays showed generally positive cytocompatibility and no impairments due to the surface modification or material grade. The best cell vitality was achieved with a scaffold consisting of snowflake-shaped monofilaments combined with a 25° braiding angle. The surface modification equips the scaffold with a release platform for function molecules (as recently demonstrated) so that a holistic approach to addressing the numerous requirements is provided.

17.
MethodsX ; 10: 102042, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36845371

RESUMEN

Complex channel planform especially the dynamics of the multi-thread river is empirically examined using the three major dimensions - bar growth, channel length and channel count. To this end, many indices have been proposed to deal with the complex channel response in the context of sediment-energy synergistic scenarios. The existing methods are primarily concerned with the linear or 1D nature of the channel and bar. The present study introduced the areal or 2-D nature of the channel and bar to capture a more realistic picture because, with same length, area of the bar may differ greatly. Therefore, we proposed four indices on channel braiding taking into consideration the area of the channel and bar. We tested our indices to the 28 reaches of the Damodar River, India that showed a significant correlation (∼80%) with the existing standard method. The major highlights of the methods are outlined as follows. •Four novel indices were proposed considering the linear and areal dimensions of the channel and bar.•Proposed indices focus on the unit-free measures with known limits enabling pragmatic comparison with self and other channels.•New methods were tested using field data implying a significant correlation with the existing methods.

18.
Polymers (Basel) ; 15(14)2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37514393

RESUMEN

Cardiovascular disease is a major threat to human health worldwide, and vascular transplantation surgery is a treatment method for this disease. Often, autologous blood vessels cannot meet the needs of surgery. However, allogeneic blood vessels have limited availability or may cause rejection reactions. Therefore, the development of biocompatible artificial blood vessels is needed to solve the problem of donor shortage. Tubular fabrics prepared by textile structures have flexible compliance, which cannot be matched by other structural blood vessels. Therefore, biomedical artificial blood vessels have been widely studied in recent decades up to the present. This article focuses on reviewing four textile methods used, at present, in the manufacture of artificial blood vessels: knitting, weaving, braiding, and electrospinning. The article mainly introduces the particular effects of different structural characteristics possessed by various textile methods on the production of artificial blood vessels, such as compliance, mechanical properties, and pore size. It was concluded that woven blood vessels possess superior mechanical properties and dimensional stability, while the knitted fabrication method facilitates excellent compliance, elasticity, and porosity of blood vessels. Additionally, the study prominently showcases the ease of rebound and compression of braided tubes, as well as the significant biological benefits of electrospinning. Moreover, moderate porosity and good mechanical strength can be achieved by changing the original structural parameters; increasing the floating warp, enlarging the braiding angle, and reducing the fiber fineness and diameter can achieve greater compliance. Furthermore, physical, chemical, or biological methods can be used to further improve the biocompatibility, antibacterial, anti-inflammatory, and endothelialization of blood vessels, thereby improving their functionality. The aim is to provide some guidance for the further development of artificial blood vessels.

19.
Cureus ; 15(12): e50140, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38186462

RESUMEN

The persistence of apical periodontitis after endodontic therapy can be attributed to biological causes or when the treatment approaches have proven insufficient in completely eradicating the intra-radicular infection. This case report describes the endodontic retreatment of a maxillary molar in which file separation occurred during the cleaning and shaping procedure. The separated file was successfully retrieved utilizing a combination of ultrasonic and braiding techniques. The field of ultrasonics has undergone a thorough investigation and has been demonstrated to be a conservative technique with minimal radicular dentin trephination. The braiding technique is also a conservative method that involves the use of several braided H-files to apply a gripping force, facilitating the extraction of foreign bodies. The utilization of this methodology has been documented in the endodontic academic literature.

20.
Pilot Feasibility Stud ; 9(1): 81, 2023 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-37173799

RESUMEN

BACKGROUND: Exposure to secondhand tobacco smoke (SHS) and child maltreatment are preventable threats to child health. Few evidence-based interventions target both SHS and child maltreatment risk. The purpose of this paper is to describe the systematic braiding process of two evidence-based programs to address child SHS in the home and maltreatment perpetration risk, and present results from the formative work and pilot study. METHODS: The first 4 steps of the systematic braiding process were completed, including the following: (1) the identification of core elements of both programs, (2) the development of an initial draft of the braided curriculum (Smoke-Free Home SafeCare - SFH-SC), (3) an acceptability and feasibility pilot of SFH-SC with caregivers of young children who reported a smoker living in the home (N = 8), and (4) feedback collection on the braided curriculum from SafeCare Providers (N = 9). RESULTS: Experts identified common pedagogical and theoretical underpinnings for the two programs and braided Smoke-Free Homes: Some Things Are Better Outside into two SafeCare modules. Caregiver feedback from the pilot demonstrated that participants were engaged with SFH-SC and felt supported and comfortable discussing SHS intervention content with the SFH-SC Provider. Caregiver self-reports indicated a slight increase in smoke-free home rules from baseline to follow-up and a notable reduction in parent stress on the Parent Stress Index of 5.9 points (SD = 10.2). SafeCare Provider feedback following intensive review of the curriculum indicated high feasibility for SFH-SC delivery. CONCLUSIONS: Parent and Provider findings suggest SFH-SC is a viable intervention that has potential to reduce the public health impact of SHS and child maltreatment for at-risk families. PROTOCOL: The protocol for the pilot is not published elsewhere; however, the full protocol for the hybrid trial can be found here: https://clinicaltrials.gov/ct2/show/NCT05000632 . TRIAL REGISTRATION: NCT, NCT05000632. Registered 14 July 2021, there is not a separate registration number for the pilot.

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