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Phospholipase A2, group VII (PLA2G7) is widely recognized as a secreted, lipoprotein-associated PLA2 in plasma that converts phospholipid platelet-activating factor (PAF) to a biologically inactive product Lyso-PAF during inflammatory response. We report that intracellular PLA2G7 is selectively important for cell proliferation and tumor growth potential of melanoma cells expressing mutant NRAS, but not cells expressing BRAF V600E. Mechanistically, PLA2G7 signals through its product Lyso-PAF to contribute to RAF1 activation by mutant NRAS, which is bypassed by BRAF V600E. Intracellular Lyso-PAF promotes p21-activated kinase 2 (PAK2) activation by binding to its catalytic domain and altering ATP kinetics, while PAK2 significantly contributes to S338-phosphorylation of RAF1 in addition to PAK1. Furthermore, the PLA2G7-PAK2 axis is also required for full activation of RAF1 in cells stimulated by epidermal growth factor (EGF) or cancer cells expressing mutant KRAS. Thus, PLA2G7 and Lyso-PAF exhibit intracellular signaling functions as key elements of RAS-RAF1 signaling.
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Fosfolípidos , Proteínas Proto-Oncogénicas B-raf , Fosfolipasas A2 , Factor de Activación Plaquetaria/análogos & derivados , Factor de Activación Plaquetaria/metabolismoRESUMEN
Dietary supplements such as vitamins and minerals are widely used in the hope of improving health but may have unidentified risks and side effects. In particular, a pathogenic link between dietary supplements and specific oncogenes remains unknown. Here we report that chondroitin-4-sulfate (CHSA), a natural glycosaminoglycan approved as a dietary supplement used for osteoarthritis, selectively promotes the tumor growth potential of BRAF V600E-expressing human melanoma cells in patient- and cell line-derived xenograft mice and confers resistance to BRAF inhibitors. Mechanistically, chondroitin sulfate glucuronyltransferase (CSGlcA-T) signals through its product CHSA to enhance casein kinase 2 (CK2)-PTEN binding and consequent phosphorylation and inhibition of PTEN, which requires CHSA chains and is essential to sustain AKT activation in BRAF V600E-expressing melanoma cells. However, this CHSA-dependent PTEN inhibition is dispensable in cancer cells expressing mutant NRAS or PI3KCA, which directly activate the PI3K-AKT pathway. These results suggest that dietary supplements may exhibit oncogene-dependent pro-tumor effects.
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Carcinógenos/toxicidad , Transformación Celular Neoplásica/genética , Sulfatos de Condroitina/toxicidad , Suplementos Dietéticos/toxicidad , Melanoma/inducido químicamente , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias Cutáneas/inducido químicamente , Animales , Antinematodos/farmacología , Quinasa de la Caseína II/metabolismo , Proliferación Celular/efectos de los fármacos , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Femenino , GTP Fosfohidrolasas/genética , Células HEK293 , Células HT29 , Humanos , Melanoma/tratamiento farmacológico , Melanoma/enzimología , Melanoma/genética , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos NOD , Ratones Desnudos , Ratones Transgénicos , Células 3T3 NIH , Proteínas Nucleares/genética , Fosfohidrolasa PTEN/antagonistas & inhibidores , Fosfohidrolasa PTEN/metabolismo , Fosforilación , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/enzimología , Neoplasias Cutáneas/genética , Factores de Transcripción/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
mDia formin proteins regulate the dynamics and organization of the cytoskeleton through their linear actin nucleation and polymerization activities. We previously showed that mDia1 deficiency leads to aberrant innate immune activation and induces myelodysplasia in a mouse model, and mDia2 regulates enucleation and cytokinesis of erythroblasts and the engraftment of hematopoietic stem and progenitor cells (HSPCs). However, whether and how mDia formins interplay and regulate hematopoiesis under physiological and stress conditions remains unknown. Here, we found that both mDia1 and mDia2 are required for HSPC regeneration under stress, such as serial plating, aging, and reconstitution after myeloid ablation. We showed that mDia1 and mDia2 form hetero-oligomers through the interactions between mDia1 GBD-DID and mDia2 DAD domains. Double knockout of mDia1 and mDia2 in hematopoietic cells synergistically impaired the filamentous actin network and serum response factor-involved transcriptional signaling, which led to declined HSPCs, severe anemia, and significant mortality in neonates and newborn mice. Our data demonstrate the potential roles of mDia hetero-oligomerization and their non-rodent functions in the regulation of HSPCs activity and orchestration of hematopoiesis.
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Actinas , Proteínas Portadoras , Ratones , Animales , Forminas/genética , Forminas/metabolismo , Actinas/genética , Actinas/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Citoesqueleto de Actina/metabolismo , Microtúbulos/metabolismoRESUMEN
Nuclear envelope membrane proteins (NEMPs) are a conserved family of nuclear envelope (NE) proteins that reside within the inner nuclear membrane (INM). Even though Nemp1 knockout (KO) mice are overtly normal, they display a pronounced splenomegaly. This phenotype and recent reports describing a requirement for NE openings during erythroblasts terminal maturation led us to examine a potential role for Nemp1 in erythropoiesis. Here, we report that Nemp1 KO mice show peripheral blood defects, anemia in neonates, ineffective erythropoiesis, splenomegaly, and stress erythropoiesis. The erythroid lineage of Nemp1 KO mice is overrepresented until the pronounced apoptosis of polychromatophilic erythroblasts. We show that NEMP1 localizes to the NE of erythroblasts and their progenitors. Mechanistically, we discovered that NEMP1 accumulates into aggregates that localize near or at the edge of NE openings and Nemp1 deficiency leads to a marked decrease of both NE openings and ensuing enucleation. Together, our results for the first time demonstrate that NEMP1 is essential for NE openings and erythropoietic maturation in vivo and provide the first mouse model of defective erythropoiesis directly linked to the loss of an INM protein.
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Membrana Nuclear , Esplenomegalia , Ratones , Animales , Eritroblastos/metabolismo , Núcleo Celular/metabolismo , Eritropoyesis/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones NoqueadosRESUMEN
The atomic force microscopy (AFM) is an important tool capable of characterization, measurement, and manipulation at the nanoscale with a vertical resolution of less than 0.1 nm. However, the conventional AFMs' scanning range is around 100 µm, which limits their capability for processing cross-scale samples. In this study, it proposes a novel approach to overcome this limitation with an ultra-large scale stitchless AFM (ULSS-AFM) that allows for the high-throughput characterization of an area of up to 1 × 1 mm2 through a synergistic integration with a compliant nano-manipulator (CNM). Specifically, the compact CNM provides planar motion with nanoscale precision and millimeter range for the sample, while the probe of the ULSS-AFM interacts with the sample. Experimental results show that the proposed ULSS-AFM performs effectively in different scanning ranges under various scanning modes, resolutions, and frequencies. Compared with the conventional AFMs, the approach enables high-throughput characterization of ultra-large scale samples without stitching or bow errors, expanding the scanning area of conventional AFMs by two orders of magnitude. This advancement opens up important avenues for cross-scale scientific research and industrial applications in nano- and microscale.
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High-power-density electronic devices under vibrations call for soft and damping thermal interface materials (TIMs) for efficient heat dissipation. However, integrating low hardness, high damping, and superior heat transfer capability into one TIM is highly challenging. Herein, soft, damping, and thermally conductive TIMs are designed and prepared by constructing a honeycomb-board-mimetic boron nitride nanosheet (BNNS) network in a dynamic polyimine via one-step horizontal centrifugal casting. The unique filler network makes the TIMs perform a high through-plane thermal conductivity (> 7.69 W m-1 K-1) and a uniform heat transfer process. Meanwhile, the hierarchical dynamic bonding of the polyimine endows the TIMs with low compressive strength (2.16 MPa at 20% strain) and excellent damping performance (tan δ > ≈0.3 at 10-2-102 Hz). The resulting TIMs also exhibit electrical insulation and remarkable recycling ability. Compared with the commercial ones, the TIMs provide better heat dissipation (4.1 °C) for a high-power 5G base station and less temperature fluctuation (1.8 °C) for an automotive insulated gate bipolar transistor (IGBT) under vibrations. This rational design offers a viable approach to prepare soft and damping TIMs for effective heat dissipation of high-power-density electronic devices under vibrations.
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Psoriasis is an immune-mediated inflammatory disease commonly accompanied by various metabolic disorders. It is widely known that biologics could affect the metabolic status and comorbidities in psoriasis patients, however, the effects of biologics on metabolism in psoriasis patients remain poorly understood. The aim of this study was to elucidate the characteristic changes of metabolic profiling in psoriasis vulgaris (PsV) patients before and after applying biologics. Plasma samples were collected from a retrospective cohort of 43 PsV patients. Non-targeted metabolomics analyses were performed using liquid chromatography-mass spectrometry (LC-MS) to compare the metabolic profiles before and after applying adalimumab (ADA) or ixekizumab (IXE) for 4 weeks. Additionally, correlation analyses were conducted to investigate the associations between metabolite expression levels and clinical characteristics. The biologics significantly affected the metabolic profiles of PsV patients especially in glycerophospholipids (GPs). First, phosphatidylcholine (PC), unsaturated lysophosphatidylcholine (LPC), unsaturated lysophosphatidic acid (LPA) and unsaturated lysophosphatidylethanolamine (LPE) were significantly up-regulated, whereas phosphatidylethanolamine (PE), saturated LPC, saturated LPA and saturated LPE were predominantly down-regulated after biologic treatment. What is more, the changes in PE and LPA were mainly observed after applying IXE instead of ADA. Second, we also found GPs including PC, unsaturated LPC, unsaturated LPA and unsaturated LPE were primarily negatively correlated with disease severity, whereas, PE, saturated LPC, saturated LPA and saturated LPE displayed inverse correlations. Biologics could affect GP metabolism and facilitate the transition of metabolic status from a pro-inflammatory to an anti-inflammatory phenotype in PsV patients.
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Productos Biológicos , Psoriasis , Humanos , Estudios Retrospectivos , Psoriasis/tratamiento farmacológico , Adalimumab/uso terapéutico , Fosfatidilcolinas , Productos Biológicos/uso terapéuticoRESUMEN
OBJECTIVE: To determine the minimal important change (MIC) and meaningful change value (MCV) of the Disease Activity Index for Psoriatic Arthritis (DAPSA) and the effect size (ES) of DAPSA. METHODS: This was a retrospective cohort study, recruiting 106 patients who agreed to participate in the research from the Department of Dermatology, Xiangya Hospital, between November 1, 2019, and April 1, 2023. An anchor-based method using linear regression analyses was used to determine the MICs and MCVs of the DAPSA. The anchor question assessed whether the patient's well-being had changed since their previous visit, employing a 5-point Likert scale that ranged from "much improved" to "much deteriorated." RESULTS: The overall MIC value was 8.4 (95% CI 0.01-16.75). The MIC improvement was 9.5 (95% CI 0.89-18.14) and MIC deterioration was 1.1 (95% CI -9.81 to 12.05). The overall MCV was 10.5 (95% CI 4.34-16.72). MCV improvement was 11.4 (95% CI 5.95-16.95) and MCV deterioration was 1.1 (95% CI -9.81 to 12.05). The ES was 0.6. CONCLUSION: A change in DAPSA of 8.4 is indicative of an MIC, offering physicians an additional means to contextualize the patient's perception of disease activity during treatment, and a change in DAPSA of 10.5 is likely to be regarded as MCV. These values can enhance the utility of DAPSA in psoriatic arthritis clinical trials.
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Artritis Psoriásica , Índice de Severidad de la Enfermedad , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Artritis Psoriásica/diagnóstico , China , Pueblos del Este de Asia , Estudios Longitudinales , Diferencia Mínima Clínicamente Importante , Estudios RetrospectivosRESUMEN
Zhujing pill (ZP) is a famous Chinese herbal formula that has been widely used to treat diabetic retinopathy, macular degeneration, retinitis pigmentosa and other fundus lesions. In this study, the material basis and mechanism of ZP in the treatment of fundus lesions were evaluated via the high-performance liquid chromatography fingerprint, ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry, network pharmacology and molecular docking. A total of 32 common components were found and 31 components were identified in 15 batches of ZP samples. Moreover, 134 common key targets and 17 putative active components that are connected to fundus lesions were identified. Molecular docking revealed that quercetin, kaempferol, isorhamnetin, 5-O-feruloylquinic acid, plantagoside and 2'-acetylacteoside have the ability to interact with the core targets such as AKT1, TP53, TNF, IL-6 and Jun. Our findings revealed that the therapeutic effects of ZP on fundus lesions are mediated by multiple components, targets and pathways, including at least six active ingredients and 11 targets. The study provides new ideas for further research on the material basis and mechanisms of traditional Chinese medicine prescriptions.
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Medicamentos Herbarios Chinos , Simulación del Acoplamiento Molecular , Farmacología en Red , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Cromatografía Líquida de Alta Presión/métodos , Humanos , Espectrometría de Masas/métodosRESUMEN
The low piezoelectricity of piezoelectric polymers significantly restricts their applications. Introducing inorganic fillers can slightly improve the piezoelectricity of polymers, whereas it is usually at the cost of flexibility and durability. In this work, using a modulus-modulated core-shell structure strategy, all-organic nanofibers with remarkable piezoelectricity were designed and prepared by a coaxial electrospinning method. It was surprisingly found that the introduction of a nonpiezoelectric polymeric core (e.g., polycarbonate, PC) can result in 110% piezoelectric coefficient (d33) enhancement in a poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE) nanofiber. Accordingly, the all-organic PVDF-TrFE@PC core-shell nanofiber exhibits record-high energy-harvesting performance (i.e., 126 V output voltage, 710 mW m-2 power density) among the reported organic piezoelectric materials. In addition, the excellent sensing capability of the core-shell nanofiber enabled us to develop a wireless vibration monitoring and analyzing system, which realizes the real-time vibration detection of a power transformer.
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Rechargeable sodium ion batteries (SIBs) have promising applications in large-scale energy storage systems. Iron-based Prussian blue analogs (PBAs) are considered as potential cathodes owing to their rigid open framework, low-cost, and simple synthesis. However, it is still a challenge to increase the sodium content in the structure of PBAs and thus suppress the generation of defects in the structure. Herein, a series of isostructural PBAs samples are synthesized and the isostructural evolution of PBAs from cubic to monoclinic after modifying the conditions is witnessed. Accompanied by, the increased sodium content and crystallinity are discovered in PBAs structure. The as-obtained sodium iron hexacyanoferrate (Na1.75 Fe[Fe(CN)6 ]0.9743 ·2.76H2 O) exhibits high charge capacity of 150 mAh g-1 at 0.1 C (17 mA g-1 ) and excellent rate performance (74 mAh g-1 at 50 C (8500 mA g-1 )). Moreover, their highly reversible Na+ ions intercalation/de-intercalation mechanism is verified by in situ Raman and Powder X-ray diffraction (PXRD) techniques. More importantly, the Na1.75 Fe[Fe(CN)6 ]0.9743 ·2.76H2 O sample can be directly assembled in a full cell with hard carbon (HC) anode and shows excellent electrochemical performances. Finally, the relationship between PBAs structure and electrochemical performance is summarized and prospected.
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Correlating metal-organic framework (MOF) synthesis processes and microwave absorption (MA) enhancement mechanisms is a pioneer project. Nevertheless, the correlation process still relies mainly on empirical doctrine, which hardly corresponds to the specific mechanism of the effect on the dielectric properties. Hereby, after the strategy of modulation of protonation engineering and solvothermal temperature in the synthesis route, the obtained sheet-like self-assembled nanoflowers were constructed. Porous structures with multiple heterointerfaces, abundant defects, and vacancies are obtained by controlled design of the synthesis procedure. The rearrangement of charges and enhanced polarization can be promoted. The designed electromagnetic properties and special nano-microstructures of functional materials have significant impact on their electromagnetic wave energy conversion effects. As a consequence, the MA performance of the samples has been enhanced toward broadband absorption (6.07 GHz), low thickness (2.0 mm), low filling (20%), and efficient loss (-25 dB), as well as being suitable for practical environmental applications. This work establishes the connection between the MOF-derived materials synthesis process and the MA enhancement mechanism, which provides insight into various microscopic microwave loss mechanisms.
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The final stages of mammalian erythropoiesis involve enucleation, membrane and proteome remodeling, and organelle clearance. Concomitantly, the erythroid membrane skeleton establishes a unique pseudohexagonal spectrin meshwork that is connected to the membrane through junctional complexes. The mechanism and signaling pathways involved in the coordination of these processes are unclear. The results of our study revealed an unexpected role of the membrane skeleton in the modulation of proteome remodeling and organelle clearance during the final stages of erythropoiesis. We found that diaphanous-related formin mDia2 is a master regulator of the integrity of the membrane skeleton through polymerization of actin protofilament in the junctional complex. The mDia2-deficient terminal erythroid cell contained a disorganized and rigid membrane skeleton that was ineffective in detaching the extruded nucleus. In addition, the disrupted skeleton failed to activate the endosomal sorting complex required for transport-III (ESCRT-III) complex, which led to a global defect in proteome remodeling, endolysosomal trafficking, and autophagic organelle clearance. Chmp5, a component of the ESCRT-III complex, is regulated by mDia2-dependent activation of the serum response factor and is essential for membrane remodeling and autophagosome-lysosome fusion. Mice with loss of Chmp5 in hematopoietic cells in vivo resembled the phenotypes in mDia2-knockout mice. Furthermore, overexpression of Chmp5 in mDia2-deficient hematopoietic stem and progenitor cells significantly restored terminal erythropoiesis in vivo. These findings reveal a formin-regulated signaling pathway that connects the membrane skeleton to proteome remodeling, enucleation, and organelle clearance during terminal erythropoiesis.
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Eritroblastos/metabolismo , Membrana Eritrocítica/metabolismo , Orgánulos/metabolismo , Proteoma/metabolismo , Animales , Autofagosomas/metabolismo , Secuencia de Bases , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Endosomas/metabolismo , Eritroblastos/ultraestructura , Membrana Eritrocítica/ultraestructura , Eritropoyesis , Lisosomas/metabolismo , Fusión de Membrana , Ratones Endogámicos C57BL , Proteínas Asociadas a Microtúbulos/deficiencia , Proteínas Asociadas a Microtúbulos/metabolismo , NADPH Deshidrogenasa/deficiencia , NADPH Deshidrogenasa/metabolismo , Orgánulos/ultraestructura , Reticulocitos/metabolismo , Reticulocitos/ultraestructuraRESUMEN
Because of the versatility of superhydrophobic materials, they have attracted a lot of attention even in power electronics, transportation, engineering, and other fields. The volume fraction of fluorinated silicon oxide nanoparticles in superhydrophobic materials is one of the most important factors. Increasing the volume fraction will decrease the stability between the coating and the hydrophobic surface. Especially, the flashover voltage of the coating gradually decreases from 10 to 35 vol.%. Meanwhile, the flashover voltage dispersion of the coating increases drastically after 30 vol.%. In order to improve the electrical properties of the superhydrophobic coating, self-assembly of surface energy differences strategy is proposed in this work. A binary filling phase of the coating is introduced by 2D boron nitride nanosheets and silicon oxide nanoparticles. Although Hexagonal boron nitride with high surface energy and low roughness, it will be spontaneously assembled and wrapped by silicon oxide nanoparticle based on surface energy differences, which forming a low surface energy filled phase. Experiment results prove that the flashover voltage of the superhydrophobic coating is optimized by the binary filling phase coating. This method offers new ideas for the selection of filling phase and application of superhydrophobic materials.
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Compuestos de Boro , Dióxido de Silicio , Propiedades de Superficie , Interacciones Hidrofóbicas e Hidrofílicas , Dióxido de Silicio/químicaRESUMEN
PURPOSE: The purpose of this paper is to evaluate the clinical and radiographic outcomes of oblique lumbar interbody fusion (OLIF) to perform in L4/5 degenerative lumbar spondylolisthesis (DLS) patients who diagnosed with osteopenia. METHODS: From December 2018 to 2021 March, 94 patients were diagnosed with degenerative spondylolisthesis underwent OLIF and divided into two groups with different bone mineral density. Anterolateral screw and rod instrumentation was applied in two groups. The primary outcomes were VAS, JOA and ODI. The secondary outcomes included disc height (DH), cross-sectional height of the intervertebral foramina (CSH), cross-sectional area of the dural sac (CSA), lumbar lordorsis (LL), pelvic titlt (PT), pelvic incidence (PI) and sacrum slop (SS). RESULTS: All patients finished at least 1 years follow-up with 21.05 ± 4.42 months in the group A and 21.09 ± 4.28 months in the group B. The clinical symptoms were evaluated by VAS, JOA and ODI and 94 patients showed good outcomes at final follow-up (P < 0.05), with significant increases in DH, CSH and CSA. In group A, DH increased from 8.54 ± 2.48 to 11.11 ± 2.63 mm, while increased from 8.60 ± 2.29 to 11.23 ± 1.88 were recorded in group B. No statistical difference was found in DH between the two groups (P > 0.05). The cage subsidence was 1.14 ± 0.83 mm in group A and 0.87 ± 1.05 mm in group B (P > 0.05). There was no significant difference in the adjusted parameters of spino-pelvic between two groups (P > 0.05). CONCLUSION: Oblique lumbar interbody fusion with anterolateral screw and rod instrumentation is feasible to be performed in osteopenia patients who diagnosed with degenerative spondylolisthesis.
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Enfermedades Óseas Metabólicas , Espondilolistesis , Humanos , Estudios Retrospectivos , Espondilolistesis/complicaciones , Espondilolistesis/diagnóstico por imagen , Espondilolistesis/cirugía , Enfermedades Óseas Metabólicas/diagnóstico por imagen , Enfermedades Óseas Metabólicas/cirugía , Tornillos Óseos , Sacro/diagnóstico por imagen , Sacro/cirugíaRESUMEN
BACKGROUND: To investigate the outcomes and safety of using minimally invasive percutaneous new transpedicular lag-screw fixation with intraoperative, full rotation, three-dimensional image (O-arm)-based navigation for the management of Hangman fracture. METHODS: Twenty-two patients with Hangman fracture were treated with minimally invasive percutaneous new transpedicular lag-screws using intraoperative, full rotation, and three-dimensional image (O-arm)-based navigation. The preoperative and postoperative conditions of the patients were evaluated according to the ASIA (American Spinal Injury Association) scale. The patient's VAS (visual analog scale) scores before and after surgery, operation time, cervical vertebral activity, intervertebral angle and bone healing were recorded and collected, and repeated measures analysis of variance was used for statistical analysis. RESULTS: All patients were satisfactorily repositioned after surgery, and the VAS scores for neck pain were significantly lower than those before surgery on the first day and at 1 month, 3 months and the last follow-up (P < 0.001). According to the ASIA scale, four patients recovered from preoperative grade D to postoperative grade E. Bony fusion was achieved for all cases, and the range of neck rotation was restored to normal at the last follow-up. The post-surgery angular displacement (AD) demonstrated the stability of C2-3 after our new screw fixation for the treatment of Hangman fracture. CONCLUSIONS: Minimally invasive percutaneous new transpedicular lag-screw fixation using intraoperative, full rotation, three-dimensional image (O-arm)-based navigation achieved satisfactory clinical results with the advantages of immediate stability, safety and effectivity. We suggest that it is a reliable and advanced technique for the management of Hangman fracture.
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Tornillos Pediculares , Fracturas de la Columna Vertebral , Cirugía Asistida por Computador , Humanos , Imagenología Tridimensional/métodos , Resultado del Tratamiento , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/cirugía , Cirugía Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Fijación Interna de Fracturas/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodosRESUMEN
Electronic conduction in solid-polymer electrolytes is generally not desired, which causes leakage of electrons or energy loss, and the electronically conductive domains at electrode-electrolyte interfaces can lead to continuous decomposition of electrolytes and shorting issues. However, it is noticed in this work that in an insulating matrix, the conductive domains at certain aspects could also have positive effects on the electrolyte performance with proper control. This work evaluates the limitation and benefits of electronically conductive domains in a solid-polymer electrolyte system and discusses the approach to improve the electrolyte physicochemical properties with densified local electric field distribution, enhanced bulk dielectric property, and charge transfer. By deliberately introducing the conductive domains in a regular solid-polymer electrolyte, stable cycle life, low overpotential, and promising full cell performance could be achieved.
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Wearable thermoelectric generators have great potential to be utilized as the power supply for wearable electronics. However, the limited temperature difference across the thermoelectric generators significantly degrades the output performance, which is anticipated to be improved by enhancing the thermal radiation at the cold side without extra energy consumption. In this paper, the impact of thermal radiation on the performance of thermoelectric generators in different environments is simulated and the enhanced performance in a wearable thermoelectric generator combined with a radiative cooling coating is experimentally verified. Compared with the pristine device, the wearable thermoelectric generator with radiative cooling coating can not only achieve an ≈128% improvement of output power in exposed environments, but also exhibit an ≈96% improvement of output power in non-exposed environments. The indoor output performance of the wearable thermoelectric generator with a radiative cooling coating due to its stable voltage output is extensively investigated, which shows an output power density of ≈5.5 µW cm-2 at the indoor temperature of 295 K, doubled that without a radiative cooling coating. This work paves a new way for further enhancing the performance of thermoelectric generators via passive radiative cooling.
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Dispositivos Electrónicos Vestibles , Frío , Suministros de Energía Eléctrica , Electrónica , TemperaturaRESUMEN
BACKGROUND: Studies on the associations between ambient temperature and asthma hospitalizations are limited, and the results are controversial. We aimed to assess the short-term effects of ambient temperature on the risk of asthma hospitalizations and quantify the hospitalization burdens of asthma attributable to non-optimal temperature in adults in Beijing, China. METHODS: We collected daily asthma hospitalizations, meteorological factors and air quality data in Beijing from 2012 to 2015. We applied a time-stratified case-crossover design and fitted a distributed lag non-linear model with a conditional quasi-Poisson regression to explore the association between ambient temperature and adult asthma hospitalizations. The effect modifications of these associations by gender and age were assessed by stratified analyses. We also computed the attributable fractions and numbers with 95% empirical confidence intervals (eCI) of asthma hospitalizations due to extreme and moderate temperatures. RESULTS: From 2012 to 2015, we identified a total of 18,500 hospitalizations for asthma among adult residents in Beijing, China. Compared with the optimal temperature (22 °C), the cumulative relative risk (CRR) over lag 0-30 days was 2.32 with a 95% confidence interval (CI) of 1.57-3.42 for extreme cold corresponding to the 2.5th percentile (- 6.5 °C) of temperature distribution and 2.04 (95% CI 1.52-2.74) for extreme heat corresponding to the 97.5th percentile (29 °C) of temperature distribution. 29.1% (95% eCI 17.5-38.0%) of adult asthma hospitalizations was attributable to non-optimum temperatures. Moderate cold temperatures yielded most of the burdens, with an attributable fraction of 20.3% (95% eCI 9.1-28.7%). The temperature-related risks of asthma hospitalizations were more prominent in females and younger people (19-64 years old). CONCLUSIONS: There was a U-shaped association between ambient temperature and the risk of adult asthma hospitalizations in Beijing, China. Females and younger patients were more vulnerable to the effects of non-optimum temperatures. Most of the burden was attributable to moderate cold. Our findings may uncover the potential impact of climate changes on asthma exacerbations.
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Asma/terapia , Hospitalización/estadística & datos numéricos , Medición de Riesgo/métodos , Temperatura , Adulto , Asma/epidemiología , Beijing/epidemiología , Estudios Cruzados , Estudios Transversales , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto JovenRESUMEN
Increasing worldwide demand for beef products promotes international beef trade. Cattle raising and beef products as significant sources of methane (CH4) emissions have received widespread concerns. However, the factors driving CH4 emissions embodied in the global beef trade have not been quantified. Here, we evaluate international beef trade-induced CH4 emissions and assess the contribution of the five driving factors to changes in CH4 emissions embodied in the beef trade from 2000 to 2018. We show that driven by increasing population and meat demands, the global beef trade-induced CH4 emissions increased continuously in the past two decades, with total emissions of 9337.3 Gg in 2018. The drivers that could potentially reduce trade-related emissions are emission intensities in beef exporting countries and beef importing countries' selections of their beef suppliers. Together, these two driving factors reduced CH4 emissions by 923.5 Gg from 2012 to 2018. Results suggest that efforts should be made to reduce the emission intensity via improving cattle feed and feeding practices in beef exporting countries. Beef importing countries could also contribute to CH4 emission reduction by selecting those beef exporting countries with low emission intensities.