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Based on experimental and computational evidence, phthalocyanine (Pc) compounds in the form of quaternary-bound metal-nitrogen (N) atoms are the most effective catalysts for oxygen reduction reaction (ORR). However, the heat treatment process used in their synthesis may compromise the ideal structure, causing the agglomeration of transition metals. To overcome this issue, a novel method is developed for synthesizing iron (Fe) single-atom catalysts with ideal structures supported by thermally exfoliated graphene oxide (GO). This is achieved through a short heat treatment of only 2.5 min involving FePc and N, N-dimethylformamide in the presence of GO. According to the synthesis mechanism revealed by this study, carbon monoxide acts as a strong linker between the single Fe atoms and graphene. It facilitates the formation of a structure containing oxygen species between FeN4 and graphene, which provides high activity and stability for the ORR. These catalysts possess an enormous number of active sites and exhibit enhanced activity toward the alkaline ORR. They demonstrate excellent performance when applied to real electrochemical devices, such as zinc-air batteries and anion exchange membrane fuel cells. It is expected that the instantaneous heat treatment method developed in this study will aid in the development of high-performing single-atom catalysts.
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Background: Intervertebral disc degeneration is associated with low back pain, which is a leading cause of disability. While the precise causes of disc degeneration are unknown, inadequate nutrient and metabolite transport through the cartilage endplate (CEP) may be one important factor. Prior work shows that CEP transport properties depend on the porosity of the CEP matrix, but little is known about the role of CEP characteristics that could influence transport properties independently from porosity. Here, we show that CEP transport properties depend on the extent of non-enzymatic glycation of the CEP matrix. Methods and Results: Using in vitro ribosylation to induce non-enzymatic glycation and promote the formation of advanced glycation end products, we found that ribosylation reduced glucose partition coefficients in human cadaveric lumbar CEP tissues by 10.7%, on average, compared with donor- and site-matched CEP tissues that did not undergo ribosylation (p = 0.04). These reductions in glucose uptake were observed in the absence of differences in CEP porosity (p = 0.89) or in the amounts of sulfated glycosaminoglycans (sGAGs, p = 0.47) or collagen (p = 0.61). To investigate whether ribosylation altered electrostatic interactions between fixed charges on the sGAG molecules and the mobile free ions, we measured the charge density in the CEP matrix using equilibrium partitioning of a cationic contrast agent using micro-computed tomography. After contrast enhancement, mean X-ray attenuation was 11.9% lower in the CEP tissues that had undergone ribosylation (p = 0.02), implying the CEP matrix was less negatively charged. Conclusions: Taken together, these findings indicate that non-enzymatic glycation negatively impacts glucose transport in the CEP independent of matrix porosity or sGAG content and that the effects may be mediated by alterations to matrix charge density.
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BACKGROUND: Ureteral reconstruction is required after surgical resection of the tumor invading the urinary tract in ovarian cancer with low incidence. There are no currently reported surgical outcomes of ureteral reconstruction during cytoreductive surgery. The aim of the study is to investigate the clinical features and surgical outcomes of ureteral reconstruction during primary, interval and secondary cytoreductive surgery for ovarian cancer. METHODS: A total of 3226 patients who underwent primary, interval or secondary cytoreductive surgery for ovarian cancer between January 2000 and May 2021 were reviewed. Fifty-six patients who underwent ureteral reconstruction during cytoreductive surgery were included in the analysis. RESULTS: Ureteral reconstruction was required in 1.7% (56/3226) of ovarian cancer patients. Of the 56 patients who underwent ureteral reconstruction during cytoreductive surgery, 35 (62.5%) had primary ovarian cancer, and 21 (37.5%) had recurrent ovarian cancer. The median tumor size invading the lower urinary tract was 2.0 cm (range, 0.4-9.5 cm). Ureteroneocystostomy with direct implantation (51.8%) and psoas hitch (8.9%), transureteroureterostomy (7.1%), and ureteroureterostomy (32.1%) were required as part of cytoreductive surgery. Complete cytoreduction with ureteral reconstruction was achieved in 83.9% (47/56) and the rest of the patient population (16.1%) achieved a gross residual tumor size of less than 1 cm. All complications, including hydronephrosis (33.9%), were managed, none resulting in long-term sequelae. In primary ovarian cancer, the 5-year disease-free survival and overall survival were 50.0% and 89.5%, respectively. In patients with recurrent ovarian cancer, the 5-year disease-free survival and overall survival were 23.6% and 64.0%, respectively. CONCLUSIONS: Ureteral reconstruction as a part of cytoreductive surgery for ovarian cancer could be performed with acceptable morbidities. Complete cytoreduction by a multidisciplinary surgical team, including urologic oncologists, should be pursued for the surgical management of ovarian cancer. TRIAL REGISTRATION: Retrospectively registered.
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Procedimientos Quirúrgicos de Citorreducción , Neoplasias Ováricas , Humanos , Femenino , Estudios Retrospectivos , Recurrencia Local de Neoplasia/patología , Carcinoma Epitelial de Ovario , Neoplasias Ováricas/patología , Resultado del TratamientoRESUMEN
Despite the development of multidimensional state-of-the-art electrode materials for constructing better lithium metal anodes (LMAs), the key factors influencing the electrochemical performance of LMAs are still poorly understood. Herein, it is demonstrated that the local lithium ion concentration at the interface between the electrode and electrolyte exerts significant influence on the electrochemical performance of LMAs. The local ion concentration is multiplied by introducing pseudocapacitive nanocarbons (PNCs) containing numerous heteroatoms, because PNCs can store large numbers of lithium ions in a pseudocapacitive manner, and promote the formation of an electrochemical double layer. The high interfacial lithium ion concentration induces the formation of lithium-rich inorganic solid-electrolyte-interface layers with high ionic conductivities, and facilitates sustainable and stable supplies of lithium ion charge carriers on the overall active surfaces of the PNCs. Accordingly, the PNC-induced LMA exhibits high Coulombic efficiencies, high rate capabilities, and stable cycling performance.
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Despite considerable development in the field of single-atom catalysts (SACs) on carbon-based materials, the reported strategies for synthesizing SACs generally rely on top-down approaches, which hinder achieving both simple and universal synthesis routes that are simultaneously applicable to various metals and nanocarbons. Here, a universal strategy for fabricating nanocarbon based-SACs using a flash bottom-up arc discharge method to mitigate these issues is reported. The ionization of elements and their recombination process during arc discharge allows the simultaneous incorporation of single metal atoms (Mn, Fe, Co, Ni, and Pt) into the crystalline carbon lattice during the formation of carbon nanohorns (CNHs) and N-doped arc graphene. The coordination environment around the Co atoms of Co1 /CNH can be modulated by a mild post-treatment with NH3 . As a result, Co1 /CNH exhibits good oxygen reduction reaction activity, showing a 1.92 times higher kinetic current density value than the commercial Pt/C catalyst in alkaline media. In a single cell experiment, Co1 /CNH exhibits the highest maximum power density of 472 mW cm-2 compared to previously reported nonprecious metal-based SACs.
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The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.
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Chitons are herbivorous invertebrates that use rows of ultrahard magnetite-based teeth connected to a flexible belt (radula) to rasp away algal deposits growing on and within rocky outcrops along coastlines around the world. Each tooth is attached to the radula by an organic structure (stylus) that provides mechanical support during feeding. However, the underlying structures within the stylus, and their subsequent function within the chiton have yet to be investigated. Here, we investigate the macrostructural architecture, the regional material and elemental distribution and subsequent nano-mechanical properties of the stylus from the Northern Pacific dwelling Cryptochiton stelleri. Using a combination of µ-CT imaging, optical and electron microscopy, as well as elemental analysis, we reveal that the stylus is a highly contoured tube, mainly composed of alpha-chitin fibers, with a complex density distribution. Nanoindentation reveals regiospecific and graded mechanical properties that can be correlated with both the elemental composition and material distribution. Finite element modeling shows that the unique macroscale architecture, material distribution and elemental gradients have been optimized to preserve the structural stability of this flexible, yet robust functionally-graded fiber-reinforced composite tube, providing effective function during rasping. Understanding these complex fiber-based structures offers promising blueprints for lightweight, multifunctional and integrated materials.
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Poliplacóforos , Diente , Animales , Óxido Ferrosoférrico , Microscopía ElectrónicaRESUMEN
BACKGROUND: Low back pain (LBP) is a major burden in Korea. Despite its high prevalence, the government and the public health sector do not address the specific evidences of symptom control and prevention of LBP to reduce long-term healthcare costs and increase the quality of life. Thus, the Korean medicine sector encourages to collection and analysis of the medical utilization pattern of patients with LBP in Korea to provide evidences of LBP control strategy as well as political decisions. METHODS: KLOS, a prospective, multi-center, patient registry pilot study will collaborate with 7 traditional Korean medicine hospitals and recruit patients with LBP into the registry. A total of 150 eligible patients with new episodes of LBP, who visit a Korean hospital without any other treatment history, will be enrolled in the registry. After enrollment, we will collect the individual characteristics of each patient, such as pain intensity, LBP-related daily disability, anthropometrics, and Health-Related Quality of Life (HRQoL) at baseline and FU1 and FU2. We will also access the patients' clinical and administrative electronic records to analyze the pattern of patients' resource utilization. Overall, the aims of KLOS are to (1) explore the general characteristics of patients with new episodes of LBP and (2) evaluate the efficacy and safety of various Korean medicine treatments for LBP, based on nationwide registry outcome collecting process. DISCUSSION: The first pilot study of prospective, multi-center registry of newly diagnosed LBP patients in traditional Korean medicine hospitals. The result of this study may show the current status of LBP patients who receive Korean medicine treatments and provide evidences for reasonable decision-making on Korean medicine healthcare policy in the future. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT02418286.
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Galvanic displacement reaction has been considered a simple method for fabricating hollow nanoparticles. However, the formation of hollow interiors in nanoparticles is not easily achieved owing to the easy oxidization of transition metals, which results in mixed morphologies, and the presence of surfactants on the nanoparticle surface, which severely deteriorates the catalytic activity. In this study, we developed a facile gram-scale methodology for the one-pot preparation of carbon-supported PtNi hollow nanoparticles as an efficient and durable oxygen reduction electrocatalyst without using stabilizing agents or additional processes. The hollow structures were evolved from sacrificial Ni nanoparticles via an in situ galvanic displacement reaction with a Pt precursor, directly following a preannealing process. By sampling the PtNi/C hollow nanoparticles at various reaction times, the structural formation mechanism was investigated using transmission electron microscopy with energy-dispersive X-ray spectroscopy mapping/line-scan profiling. We found out that the structure and morphology of the PtNi hollow nanoparticles were controlled by the acidity of the metal precursor solution and the nanoparticle core size. The synthesized PtNi hollow nanoparticles acted as an oxygen reduction electrocatalyst, with a catalytic activity superior to that of a commercial Pt catalyst. Even after 10â¯000 cycles of harsh accelerated durability testing, the PtNi/C hollow electrocatalyst showed high performance and durability. We concluded that the Pt-rich layers on the PtNi hollow nanoparticles improved the catalytic activity and durability considerably.
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Biological materials found in Nature such as nacre and bone are well recognized as light-weight, strong, and tough structural materials. The remarkable toughness and damage tolerance of such biological materials are conferred through hierarchical assembly of their multiscale (i.e., atomic- to macroscale) architectures and components. Herein, the toughening mechanisms of different organisms at multilength scales are identified and summarized: macromolecular deformation, chemical bond breakage, and biomineral crystal imperfections at the atomic scale; biopolymer fibril reconfiguration/deformation and biomineral nanoparticle/nanoplatelet/nanorod translation, and crack reorientation at the nanoscale; crack deflection and twisting by characteristic features such as tubules and lamellae at the microscale; and structure and morphology optimization at the macroscale. In addition, the actual loading conditions of the natural organisms are different, leading to energy dissipation occurring at different time scales. These toughening mechanisms are further illustrated by comparing the experimental results with computational modeling. Modeling methods at different length and time scales are reviewed. Examples of biomimetic designs that realize the multiscale toughening mechanisms in engineering materials are introduced. Indeed, there is still plenty of room mimicking the strong and tough biological designs at the multilength and time scale in Nature.
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Materiales Biomiméticos , Fenómenos Mecánicos , Animales , Materiales Biomiméticos/química , Biopolímeros/química , HumanosRESUMEN
In the brain, a reduction in extracellular osmolality causes water-influx and swelling, which subsequently triggers Cl-- and osmolytes-efflux via volume-regulated anion channel (VRAC). Although LRRC8 family has been recently proposed as the pore-forming VRAC which is activated by low cytoplasmic ionic strength but not by swelling, the molecular identity of the pore-forming swelling-dependent VRAC (VRACswell) remains unclear. Here we identify and characterize Tweety-homologs (TTYH1, TTYH2, TTYH3) as the major VRACswell in astrocytes. Gene-silencing of all Ttyh1/2/3 eliminated hypo-osmotic-solution-induced Cl- conductance (ICl,swell) in cultured and hippocampal astrocytes. When heterologously expressed in HEK293T or CHO-K1 cells, each TTYH isoform showed a significant ICl,swell with similar aquaporin-4 dependency, pharmacological properties and glutamate permeability as ICl,swell observed in native astrocytes. Mutagenesis-based structure-activity analysis revealed that positively charged arginine residue at 165 in TTYH1 and 164 in TTYH2 is critical for the formation of the channel-pore. Our results demonstrate that TTYH family confers the bona fide VRACswell in the brain.
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BACKGROUND: Low back pain (LBP) is common, with a lifetime prevalence of 80%, and as such it places substantial social and economic burden on individuals and society. Chuna manual therapy (CMT) combines aspects of physiology, biodynamics of spine and joint motion, and basic theory of movement dynamics. This study aimed to test the comparative effectiveness and safety of CMT for non-acute LBP. METHODS: A three-arm, multicenter, pragmatic, randomized controlled pilot trial was conducted from 28 March 2016 to 19 September 2016, at four medical institutions. A total of 60 patients were randomly allocated to the CMT group (n = 20), usual care (UC) group (n = 20), or combined treatment (CMT + UC) group (n = 20), and received the relevant treatments for 6 weeks. The primary outcome was a numeric rating scale (NRS) representation of LBP intensity, while secondary outcomes included NRS of leg pain, Oswestry disability index (ODI), Patient Global Impression of Change (PGIC), the EuroQol-5 dimensions (EQ-5D), lumbar range of motion, and safety. RESULTS: A total of 60 patients were included in the intention-to-treat analysis and 55 patients (CMT, 18; UC, 18; CMT + UC, 19) were included in the per-protocol analysis (drop-out rate 5.3%). Over the treatment period there were significant differences in the NRS score for LBP (CMT mean - 3.28 (95% CI - 4.08, - 2.47); UC - 1.95 (- 2.82, - 1.08); CMT + UC - 1.75 (- 2.70, - 0.80), P < 0.01) and the ODI scores in each group (CMT - 12.29 (- 16.86, - 7.72); UC - 10.34 (- 14.63, - 6.06); CMT + UC - 9.27 (- 14.28, - 4.26), P < 0.01). The changes in other secondary outcomes did not significantly differ among the three groups. Sixteen minor-to-moderate safety concerns were reported. CONCLUSIONS: Our results suggest that CMT has comparative efficacy for non-acute LBP and is generally safe. As this was a preliminary study, a well-powered (over 192 participants) two-arm (CMT versus UC) verification trial will be performed to assess the generalizability of these results. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0001850 . Registered on 12 March 2016.
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Dolor de la Región Lumbar/terapia , Manipulaciones Musculoesqueléticas/métodos , Adulto , Investigación sobre la Eficacia Comparativa , Femenino , Humanos , Masculino , Persona de Mediana Edad , Manipulaciones Musculoesqueléticas/efectos adversos , Proyectos Piloto , Rango del Movimiento ArticularRESUMEN
As with most biological materials, natural bone has hierarchical structure. The microstructural features of compact bone are of various length scales with its porosity consisting of larger osteons (â¼100 µm diameter) and vascular channels, as well as smaller lacuna spaces (â¼10 µm diameter). In this study, the freeze-casting process, which has been previously used to form biocompatible porous scaffolds (made with hydroxyapatite, HA) has been improved to mimic the intrinsic hierarchical structure of natural bone by implementing an extrinsic 3D printed template. The results of pore characterization showed that this novel combined method of 3D printing and freeze-casting is able to produce porosity at multiple length scales. Nonporous, microporous (created with freeze-casting alone), and macro-micro porous (created with freeze-casting and 3D printed templating) scaffolds were compared as substrates to evaluate cellular activities using osteoblast-like MG63 cell lines. The number of cells oriented parallel to the HA wall structures in the freeze-cast scaffold was found to increase on the microporous and macro-micro porous samples when compare to the nonporous samples, mimicking the natural alignment of the lamella of natural bone. Regarding the cell morphologies, cells on microporous and macro-micro porous samples showed narrowly aligned shapes, whereas those on nonporous samples had polygonal shapes with no discernible orientation. Proliferation and differentiation tests demonstrated that no toxicity or functional abnormalities were found in any of the substrates due to potential chemical and mechanical residues that may have been introduced by the freeze-casting process. Monitoring of the three-dimensional distribution of cells in the scaffolds through microcomputed tomography indicates that the cells were well distributed in the interior pore spaces via the interpenetrating macro-micro pore networks. In summary, we demonstrate this novel approach can create porosity at multiple length scales and is highly favorable in creating a biocompatible, osteoconductive, and structurally hierarchical HA scaffolds for biomedical applications.
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ETHNOPHARMACOLOGICAL RELEVANCE: Dangguisusan (DGSS) is a widely used prescription for the treatment of traumatic injury in Korean medicine. AIM OF THE STUDY: To demonstrate the effects of DGSS on a mouse model of traumatic brain injury (TBI) for providing scientific evidence in clinical use. MATERIALS AND METHODS: TBI was induced in a mouse model using the controlled cortical impact method. Water extract of DGSS (50, 150, and 450â¯mg/kg) was administered twice a day for 8 d. Histological analyses were performed 8 d after TBI. Moreover, beam-walking, grip-strength, and novel object recognition (NOR) tests were conducted to evaluate the effects on motor function, muscle strength, and cognitive memory function, respectively. RESULT: DGSS inhibited body weight loss, hippocampal damage, and neuronal loss in the thalamic region. Furthermore, it reduced transverse time and foot faults in the beam-walking test at 3 d and increased the muscle strength in the grip-strength test at 3 and 8 d. It also improved the recognition index (%) in the NOR test. However, DGSS did not show protective effects against total damage. CONCLUSIONS: DGSS might improve sensory-motor and cognitive functions after TBI with partial protective effects against brain damage. The present findings provide a scientific basis for the clinical use of DGSS in TBI.
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Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Fármacos Neuroprotectores/uso terapéutico , Extractos Vegetales/uso terapéutico , Animales , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Hipocampo/efectos de los fármacos , Masculino , Ratones Endogámicos ICR , Neuronas/efectos de los fármacosRESUMEN
Woodpeckers peck at trees without any reported brain injury despite undergoing high impact loads. Amongst the adaptations allowing this is a highly functionalized impact-absorption system consisting of the head, beak, tongue and hyoid bone. This study aims to examine the anatomical structure, composition, and mechanical properties of the skull to determine its potential role in energy absorption and dissipation. An acorn woodpecker and a domestic chicken are compared through micro-computed tomography to analyze and compare two- and three-dimensional bone morphometry. Optical and scanning electron microscopy with energy dispersive X-ray spectroscopy are used to identify the structural and chemical components. Nanoindentation reveals mechanical properties along the transverse cross-section, normal to the direction of impact. Results show two different strategies: the skull bone of the woodpecker shows a relatively small but uniform level of closed porosity, a higher degree of mineralization, and a higher cortical to skull bone ratio. Conversely, the chicken skull bone shows a wide range of both open and closed porosity (volume fraction), a lower degree of mineralization, and a lower cortical to skull bone ratio. This structural difference affects the mechanical properties: the skull bones of woodpeckers are slightly stiffer than those of chickens. Furthermore, the Young's modulus of the woodpecker frontal bone is significantly higher than that of the parietal bone. These new findings may be useful to potential engineered design applications, as well as future work to understand how woodpeckers avoid brain injury.
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Pollos , Fenómenos Mecánicos , Cráneo , Animales , Fenómenos Biomecánicos , Ensayo de Materiales , Nanotecnología , Cráneo/química , Cráneo/diagnóstico por imagen , Microtomografía por Rayos XRESUMEN
Bighorn sheep (Ovis canadensis) rams hurl themselves at each other at speeds of â¼9â¯m/s (20â¯mph) to fight for dominance and mating rights. This necessitates impact resistance and energy absorption mechanisms, which stem from material-structure components in horns. In this study, the material hierarchical structure as well as correlations between the structure and mechanical properties are investigated. The major microstructural elements of horns are found as tubules and cell lamellae, which are oriented with (â¼30°) angle with respect to each other. The cell lamellae contain keratin cells, in the shape of pancakes, possessing an average thickness of â¼2⯵m and diameter of â¼20-30⯵m. The morphology of keratin cells reveals the presence of keratin fibers and intermediate filaments with diameter of â¼200â¯nm and â¼12â¯nm, respectively, parallel to the cell surface. Quasi-static and high strain rate impact experiments, in different loading directions and hydration states, revealed a strong strain rate dependency for both dried and hydrated conditions. A strong anisotropy behavior was observed under impact for the dried state. The results show that the radial direction is the most preferable impact orientation because of its superior energy absorption. Detailed failure mechanisms under the aforementioned conditions are examined by bar impact recovery experiments. Shear banding, buckling of cell lamellae, and delamination in longitudinal and transverse direction were identified as the cause for strain softening under high strain rate impact. While collapse of tubules occurs in both quasi-static and impact tests, in radial and transverse directions, the former leads to more energy absorption and impact resistance. STATEMENT OF SIGNIFICANCE: Bighorn sheep (Ovis canadensis) horns show remarkable impact resistance and energy absorption when undergoing high speed impact during the intraspecific fights. The present work illustrates the hierarchical structure of bighorn sheep horn at different length scales and investigates the energy dissipation mechanisms under different strain rates, loading orientations and hydration states. These results demonstrate how horn dissipates large amounts of energy, thus provide a new path to fabricate energy absorbent and crashworthiness engineering materials.
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Fuerza Compresiva , Cuernos/química , Queratinas/química , Estrés Mecánico , Animales , Anisotropía , Cuernos/anatomía & histología , OvinosRESUMEN
Epimedii Herba (EH) is an herbal medicine originating from several plants of the genus Epimedium. It is a major therapeutic option for kidney yang deficiency syndrome, which is closely related to androgen hormones and also has been used to treat hemiplegia following a stroke in traditional medicine of Korea and PR China. To date, many clinical and basic researches of EH have shown the activities on functional recovery from brain diseases. Recently, neuroplasticity, which is the spontaneous reaction of the brain in response to diseases, has been shown to accelerate functional recovery. In addition, androgen hormones including testosterone are known to be the representative of neuroplasticity factors in the brain recovery processes. In this review, we described the neuro-pharmacological activities of EH, focusing on neuroplasticity. Thirty-three kinds of papers from MEDLINE/PubMed, EMBASE, and CNKI were identified and analyzed. We categorized the results into five types based on neuroplasticity mechanisms and presented the definition of each category and briefly described the results of these papers. Altogether, we can suggest that neuroplasticity is a novel viewpoint for guiding future brain research of EH and provide the evidence for the development of new clinical applications using EH in the treatment of brain diseases. Copyright © 2017 John Wiley & Sons, Ltd.
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Medicamentos Herbarios Chinos/farmacología , Epimedium/química , Plasticidad Neuronal/efectos de los fármacos , Animales , Encéfalo/efectos de los fármacos , China , Humanos , Medicina Tradicional China , Fitoterapia , Plantas Medicinales/química , República de CoreaRESUMEN
Animal propulsion systems are believed to show high energy and mechanical efficiency in assisting movement compared to artificial designs. As an example, batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming via enlarged wing-like pectoral fins. The aim of this work is to illustrate the hierarchical structure of the pectoral fin of a representative batoid, the Longnose Skate (Raja rhina), and explain the mechanical implications of its structural design. At the macro level, the pectoral fins are comprised of radially oriented fin rays, formed by staggered mineralized skeletal elements stacked end-to-end. At the micro level, the midsection of each radial element is composed of three mineralized components, which consist of discrete segments (tesserae) that are mineralized cartilage and embedded in unmineralized cartilage. The radial elements are wrapped with aligned, unmineralized collagen fibers. This is the first report of the detailed structure of the ray elements, including the observation of a 3-chain mineralized tesserae. Structural analyses demonstrate that this configuration enhances stiffness in multiple directions. A two-dimensional numerical model based on the morphological analysis demonstrated that the tessera structure helps distributing shear, tensile and compressive stress more ideally, which can better support both lift and thrust forces when swimming without losing flexibility. STATEMENT OF SIGNIFICANCE: Batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming by applying their enlarged wing-like pectoral fins. Previous studies have shown structural features and mechanical properties of the mineralized cartilage skeleton in various batoid fishes. However, the details of the pectoral fin structure at different length scales, as well as the relationship between the mechanical properties and structural design remains unknown. The present work illustrates the hierarchical structure of the pectoral fin of the Longnose Skate (a representative batoid fish) and verifies the materials configuration and structural design increases the stiffness of fin skeleton without a loss in flexibility. These results have implications for the design of strong but flexible materials and bio-inspired autonomous underwater vehicles (AUVs).
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Aletas de Animales/anatomía & histología , Aletas de Animales/fisiología , Huesos/anatomía & histología , Huesos/fisiología , Rajidae/fisiología , Aletas de Animales/ultraestructura , Animales , Fenómenos Biomecánicos , Huesos/diagnóstico por imagen , Huesos/ultraestructura , Calcificación Fisiológica , Espectrometría por Rayos X , Natación , Resistencia a la Tracción , Microtomografía por Rayos XRESUMEN
BACKGROUND: While Chuna manual therapy is a Korean manual therapy widely used primarily for low back pain (LBP)-related disorders in Korea, well-designed studies on the comparative effectiveness of Chuna manual therapy are scarce. METHODS/DESIGN: This study is the protocol for a three-armed, multicenter, pragmatic randomized controlled pilot trial. Sixty severe nonacute LBP patients (pain duration of at least 3 weeks, Numeric Rating Scale (NRS) ≥5) will be recruited at four Korean medicine hospitals. Participants will be randomly allocated to the Chuna group (n = 20), usual care group (n = 20), or Chuna plus usual care group (n = 20) for 6 weeks of treatment. Usual care will consist of orally administered conventional medicine, physical therapy, and back pain care education. The trial will be conducted with outcome assessor and statistician blinding. The primary endpoint will be NRS of LBP at week 7 post randomization. Secondary outcomes include NRS of leg pain, the Oswestry Disability Index (ODI), the Patient Global Impression of Change (PGIC), the Credibility and Expectancy Questionnaire, lumbar range of motion (ROM), the EuroQol-5 Dimension (EQ-5D) health survey, the Health Utility Index III (HUI-III), and economic evaluation and safety data. Post-treatment follow-ups will be conducted at 1, 4, and 10 weeks after conclusion of treatment. DISCUSSION: This study will assess the comparative effectiveness of Chuna manual therapy compared to conventional usual care. Costs and effectiveness (utility) data will be analyzed for exploratory cost-effectiveness analysis. If this pilot study does not reach a definite conclusion due to its small sample size, these results will be used as preliminary results to calculate sample size for future large-scale clinical trials and contribute in the assessment of feasibility of a full-scale multicenter trial. TRIAL REGISTRATION: Clinical Research Information Service (CRIS), KCT0001850 . Registered on 17 March 2016.
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Costos de la Atención en Salud , Dolor de la Región Lumbar/economía , Dolor de la Región Lumbar/terapia , Manipulaciones Musculoesqueléticas/economía , Adulto , Anciano , Protocolos Clínicos , Investigación sobre la Eficacia Comparativa , Análisis Costo-Beneficio , Evaluación de la Discapacidad , Femenino , Humanos , Dolor de la Región Lumbar/diagnóstico , Dolor de la Región Lumbar/fisiopatología , Masculino , Persona de Mediana Edad , Manipulaciones Musculoesqueléticas/efectos adversos , Dimensión del Dolor , Proyectos Piloto , Recuperación de la Función , República de Corea , Proyectos de Investigación , Encuestas y Cuestionarios , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
Purpose. This study aims to verify the effects of electroacupuncture treatment on osteoarthritis of the knee. Methods. MEDLINE/PubMed, EMBASE, CENTRAL, AMED, CNKI, and five Korean databases were searched by predefined search strategies to screen eligible randomized controlled studies meeting established criteria. Any risk of bias in the included studies was assessed with the Cochrane Collaboration's tool. Meta-analysis was conducted using RevMan version 5.3 software. Results. Thirty-one randomized controlled studies of 3,187 participants were included in this systematic review. Meta-analysis was conducted with eight studies including a total of 1,220 participants. The electroacupuncture treatment group showed more significant improvement in pain due to knee osteoarthritis than the control group (SMD -1.86, 95% CI -2.33 to -1.39, I2 75%) and in total WOMAC score than the control group (SMD -1.34, CI 95% -1.85 to -0.83, I2 73%). Compared to the control group, the electroacupuncture treatment group showed more significant improvement on the quality of life scale. Conclusion. Electroacupuncture treatment can relieve the pain of osteoarthritis of the knees and improve comprehensive aspects of knee osteoarthritis and the quality of life of patients with knee osteoarthritis.