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A series of thienoisoindigo (TIG)-based conjugated polymers (CPs) with high molecular weights are synthesized by direct arylation polycondensation (DArP) by using TIG derivatives as CBr monomer and multi-halogenated thiophene derivatives, i.e., (E)-1,2-bis(3,4-difluorothien-2-yl)ethene (4FTVT), (E)-1,2-bis(3,4-dichlorothien-2-yl)ethene (4ClTVT), 3,3',4,4'-tetrafluoro-2,2'-bithiophene (4FBT), and 3,3',4,4'-tetrachloro-2,2'-bithiophene (4ClBT), as CH monomers. Density functional theory (DFT) calculations reveal the high selectivity between α-CH bonds in 4FTVT, 4ClTVT, 4FBT, and 4ClBT and ß-CH bonds in TIG CBr monomer. All four resulting CPs exhibit low optical bandgaps of ca. 1.20 eV and ambipolar transport characteristics with both electron and hole mobility above 0.1 cm2 V-1 s-1 as elaborated with organic thin-film transistors (OTFTs). The polymer TIG-4FTVT delivers the best device performance. With this polymer, n-channel OTFTs with electron mobility up to 1.67 cm2 V-1 s-1 and p-channel OTFTs with hole mobility up to 0.62 cm2 V-1 s-1 are fabricated by modifying source/drain electrodes with polyethylenimine ethoxylated (PEIE) and MoO3 , respectively, to selectively inject electrons and holes.
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Etilenos , Polímeros , Polímeros/química , Tiofenos/química , ElectronesRESUMEN
The performance of two-dimensional transition-metal (oxy)hydroxides (TMOOHs) for the electrocatalytic oxygen evolution reaction (OER), as well as their large-scale practical applications, are severely limited by the sluggish kinetics of the four-electron OER process. Herein, using a symmetry-breaking strategy, we simulated a complex catalyst composed of a single Co atom and a 1,10-phenanthroline (phen) ligand on CoOOH through density functional theory studies, which exhibits excellent OER performance. The active site Co undergoes a valence oscillation between +2, +3 and even high valence +4 oxidation states during the catalytic process, resulting from the distorted coordination effect after the ligand modification. The induced asymmetry in the electronic states of surrounding nitrogen and oxygen atoms modulates the eg occupation of Co-3d orbitals, which should be of benefit to reduce the overpotential in the OER process. By studying similar catalytic systems, the prominent role of ligands in creating asymmetric electronic structures and in modulating the valence of the active site and the OER performance was reconfirmed. This study provides a new dimension for optimizing the electrocatalytic performance of various TM-ligand complexes.
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Electroreduction of nitric oxide (NO) to NH3 (NORR) has gained extensive attention for the sake of low carbon emission and air pollutant treatment. Unfortunately, NORR is greatly hindered by its sluggish kinetics, especially under low concentrations of NO. Herein, we developed a chlorine (Cl) vacancy strategy to overcome this limitation over FeOCl nanosheets (FeOCl-VCl ). Density functional theory (DFT) calculations revealed that the Cl vacancy resulted in defective Fe with sharp d-states characteristics in FeOCl-VCl to enhance the absorption and activation of NO. In situ X-ray absorption near-edge structure (XANES) and attenuated total reflection-infrared spectroscopy (ATR-IR) verified the lower average oxidation state of defective Fe to enhance the electron transfer for NO adsorption/activation and facilitate the generation of key NHO and NHx intermediates. As a result, the FeOCl-VCl exhibited superior NORR activities with the NH3 Faradaic efficiency up to 91.1 % while maintaining a high NH3 yield rate of 455.4â µg cm-2 h-1 under 1.0â vol % NO concentration, competitive with those of previously reported literatures under higher NO concentration. Further, the assembled Zn-NO battery utilizing FeOCl-VCl as cathode delivered a record peak power density of 6.2â mW cm-2 , offering a new route for simultaneous NO removal, NH3 production, and energy supply.
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Dispersion relations govern wave behaviors, and tailoring them is a grand challenge in wave manipulation. We demonstrate the inverse design of phononic dispersion using nonlocal interactions on one-dimensional spring-mass chains. For both single-band and double-band cases, we can achieve any valid dispersion curves with analytical precision. We further employ our method to design phononic crystals with multiple ordinary (roton or maxon) and higher-order (undulation) critical points and investigate their wave packet dynamics.
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This study develops a framework for determining the material parameters of layered engineered wood in a nondestructive manner. The motivation lies in enhancing nondestructive evaluation (NDE) and quality assurance (QA) for engineered wood or mass timber, promising construction materials for sustainable and resilient civil structures. The study employs static compression tests, guided wave measurements, and a genetic algorithm (GA) to solve the inverse problem of determining the mechanical properties of a laminated veneer lumber (LVL) bar. Miniature LVL samples are subjected to compression tests to derive the elastic moduli and Poisson's ratios. Due to the intrinsic heterogeneity, the destructive compression tests yield large coefficients of variances ranging from 2.5 to 73.2%. Dispersion relations are obtained from spatial-temporal sampling of dynamic responses of the LVL bar. The GA pinpoints optimal mechanical properties by updating orthotropic elastic constants of the LVL material, and thereby dispersion curves, in a COMSOL simulation in accordance with experimental dispersion relations. The proposed framework can support estimation accuracy with errors less than 10% for most elastic constants. Focusing on vertical flexural modes, the estimated elastic constants generally resemble reference values from compression tests. This is the first study that evaluates the feasibility of using guided waves and multi-variable optimization to gauge the mechanical traits of LVL and establishes the foundation for further advances in the study of layered engineered wood structures.
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The unique structures of polynuclear MoxSy clusters make it possible to maximize the number of their active sites and for them to be good candidates for HER catalysts. An appropriate support is highly necessary not only to avoid the desorption of MoxSy clusters in a working environment, but also to improve their HER activity. Our work here shows that the CeO2 support could provide strong support for interaction with various MoxSy clusters and the formed MoxSy/CeO2 hetero-structures also have modest ΔGH* for the HER. The electronic features of MoxSy clusters are regulated by the CeO2 support, which leads to charge redistribution on edge atoms and plays a key role in H adsorption. Our studies provide instructive predictions on efficient candidates of molybdenum-sulfur based catalysts for the HER.
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Cementation of a highly cross-linked polyethylene liner into a well-fixed acetabular shell provided a good durability for liner wear. However, its efficacy in treating recurrent instability due to malposition cup is less reported. The aim of this study is to evaluate the outcome of this surgical technique to treat hip instability. From 2009 to 2019, we have identified 38 patients who had been surgically treated for recurrent instability, including cementation liner (N = 20) and revision cup (N = 18) procedures. Patients were followed for a mean of 45.66 months. We have recorded and analyzed all causes of implant failure including recurrent instability. Clinical outcomes were assessed including complication and Harris Hip Score (HHS) preoperatively and at the latest follow-up. Revision-free survivorship for any cause was 95.0% at 1 year, and 84.4% at 5 years in cementation liner group and 88.9% at 1 year and 5 years in revision cup group. Mean Harris hip score improved from 48.3 points preoperatively to 79.5 points at the last follow-up in cementation liner group and mean HHS improved from 43.3 points preoperatively to 77.2 points in revision cup group. There were two implant failures in each group, including one is due to persistent hip instability and the other is due to periprosthetic joint infection in the cementation liner group and two implant failure are due to persistent hip instability in the revision cup group. Functional scores and implant survival were similar in both groups. We demonstrated that orientation correction via the cementation of the polyethylene liner into well-fixed acetabular shell is a promising option to treat and prevent instability. Level of Evidence: Therapeutic Level IV.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Cementos para Huesos/uso terapéutico , Cementación/métodos , Luxaciones Articulares/terapia , Falla de Prótesis/efectos adversos , Acetábulo/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera/instrumentación , Femenino , Estudios de Seguimiento , Prótesis de Cadera/efectos adversos , Humanos , Luxaciones Articulares/etiología , Masculino , Persona de Mediana Edad , Polietileno , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: To evaluate the therapeutic efficacy of a steroid switch from prednisone to dexamethasone in Asians with metastatic castration-resistant prostate cancer (mCRPC) that progressed after docetaxel chemotherapy. METHODS: This study included postdocetaxel patients with mCRPC treated with abiraterone acetate combined with prednisone (AA + P) who had experienced prostate-specific antigen (PSA) progression. All patients underwent a steroid switch from prednisone (10 mg/day) to dexamethasone (1 mg/day). The PSA level and clinical symptoms were recorded. Moreover, follow-up was conducted until patients were either lost to follow-up or death. RESULTS: This study included 11 patients from a single center in Taiwan. The median follow-up time starting from AA + P treatment was 19.47 months. Seven patients (63.64%) had >30% PSA decline, and 6 patients (54.55%) had >50% PSA decline. The median percentage of PSA decline was 83.6%. The median time until PSA progression after the steroid switch was 11.38 months. No adverse events greater than grade 3 were noted. CONCLUSIONS: Steroid switching is a feasible and effective therapy in docetaxel-treated Asian patients with mCRPC.
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Dexametasona/uso terapéutico , Sustitución de Medicamentos , Glucocorticoides/uso terapéutico , Prednisona/uso terapéutico , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Acetato de Abiraterona/uso terapéutico , Antineoplásicos/uso terapéutico , Humanos , Masculino , Metástasis de la Neoplasia , Neoplasias de la Próstata Resistentes a la Castración/patología , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
PURPOSE: The recycled autograft in biological reconstruction for osteosarcoma has satisfactory outcome. There are few studies about its efficacy in pathological fracture. The aim of the study is to compare the clinical results of recycled autograft to those of allograft in patients with high-grade osteosarcoma with pathological fracture. PATIENTS AND METHODS: Between October 2010 and March 2018, 30 patients with osteosarcoma combining pathological fracture underwent biological reconstruction. Eleven patients received recycled autograft via extracorporeal irradiation or freezing nitrogen and nineteen patients restored bone defect via allograft to accomplish biological reconstruction. RESULTS: The mean follow-up was 58.1 months (range 12-120). The mean time to graft-host union of limbs reconstructed using recycled autografts and allografts was 17.45 ± 13.54 and 12.63 ± 12.62 months, respectively, with no significant difference observed between groups (p = 0.176). The five year probability of graft failure therefore did not significantly differ between groups (p = 0.245). The patient five year survival rate was similar (p = 0.229). Post-operative complication rates were similar for the recycled autograft group (54.5%) and the allograft group (57.9%). CONCLUSION: The recycled autograft showed comparable clinical results, graft-host union time, complication rate, and graft survival to allograft in biological reconstruction for osteosarcoma with pathological fracture.
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Neoplasias Óseas , Fracturas Espontáneas , Osteosarcoma , Aloinjertos , Autoinjertos , Neoplasias Óseas/cirugía , Fracturas Espontáneas/etiología , Fracturas Espontáneas/cirugía , Humanos , Osteosarcoma/cirugíaRESUMEN
Microtubule actin cross-linking factor 1 (Macf1) is a spectraplakin family member known to regulate cytoskeletal dynamics, cell migration, neuronal growth and cell signal transduction. We previously demonstrated that knockdown of Macf1 inhibited the differentiation of MC3T3-E1 cell line. However, whether Macf1 could regulate bone formation in vivo is unclear. To study the function and mechanism of Macf1 in bone formation and osteogenic differentiation, we established osteoblast-specific Osterix (Osx) promoter-driven Macf1 conditional knockout mice (Macf1f/f Osx-Cre). The Macf1f/f Osx-Cre mice displayed delayed ossification and decreased bone mass. Morphological and mechanical studies showed deteriorated trabecular microarchitecture and impaired biomechanical strength of femur in Macf1f/f Osx-Cre mice. In addition, the differentiation of primary osteoblasts isolated from calvaria was inhibited in Macf1f/f Osx-Cre mice. Deficiency of Macf1 in primary osteoblasts inhibited the expression of osteogenic marker genes (Col1, Runx2 and Alp) and the number of mineralized nodules. Furthermore, deficiency of Macf1 attenuated Bmp2/Smad/Runx2 signalling in primary osteoblasts of Macf1f/f Osx-Cre mice. Together, these results indicated that Macf1 plays a significant role in bone formation and osteoblast differentiation by regulating Bmp2/Smad/Runx2 pathway, suggesting that Macf1 might be a therapeutic target for bone disease.
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Proteína Morfogenética Ósea 2/metabolismo , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Proteínas de Microfilamentos/deficiencia , Osteoblastos/metabolismo , Osteogénesis , Transducción de Señal , Proteínas Smad/metabolismo , Factor de Transcripción Sp7/metabolismo , Animales , Fenómenos Biomecánicos , Huesos/anatomía & histología , Huesos/fisiología , Diferenciación Celular , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas de Microfilamentos/metabolismo , Tamaño de los Órganos , Osteoblastos/citologíaRESUMEN
BACKGROUND: Bone tumors are often treated with intralesional curettage. High-speed burring, an adjuvant therapy, was performed to maximize the tumor cell killing; however, tumor recurrence might still occur, which may be caused by residual tumor or local tumor spread during surgery. METHODS: A porcine cadaver (femur) was utilized to determine whether the use of a high-speed burr causes bone cement spray. To mimic residual tumor after curettage, luminescent cement was smeared on two locations of the bone cavity, the wall and the bottom. The cavity in the femoral bone was then placed in the middle of a sheet of drawing paper featuring 10 cm, 20 cm, and 30 cm concentric circles. The luminescent cement was then burred totally with a high-speed burr. RESULTS: The intensity of the area in the wall in circle I was 72.6% ± 5.8%; within circle II, it was 22.1% ± 4.2%; and within circle III, it was 5.4% ± 1.5%. The intensity of the area within the bottom of the femoral bone within circle I was 66.5% ± 6.1%, within circle II was 28.1 ± 4.8%, and within circle III, it was 5.4% ± 1.4%. The amount of luminescent cement seeding decreased with distance, but there was no difference while burring at different locations of the bone cavity. Under the handpiece cover, a greater amount of cement spray was retained in circle I during burring of the cement in the bottom of the cavity and less was sprayed out in circle III. CONCLUSIONS: High-speed burring may cause explosive bone cement spray, which could extend to 20 cm. The intensities of spray did not decrease, even when the handpiece cover was used. The wide range of bone cement spray caused by high-speed burr was inspected in this pilot study, which may lead to tumor seeding. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
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Neoplasias Óseas , Tumor Óseo de Células Gigantes , Animales , Cementos para Huesos , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/cirugía , Legrado , Tumor Óseo de Células Gigantes/cirugía , Recurrencia Local de Neoplasia , Proyectos Piloto , Estudios Retrospectivos , PorcinosRESUMEN
Although the human visual system is remarkable at perceiving and interpreting motions, it has limited sensitivity, and we cannot see motions that are smaller than some threshold. Although difficult to visualize, tiny motions below this threshold are important and can reveal physical mechanisms, or be precursors to large motions in the case of mechanical failure. Here, we present a "motion microscope," a computational tool that quantifies tiny motions in videos and then visualizes them by producing a new video in which the motions are made large enough to see. Three scientific visualizations are shown, spanning macroscopic to nanoscopic length scales. They are the resonant vibrations of a bridge demonstrating simultaneous spatial and temporal modal analysis, micrometer vibrations of a metamaterial demonstrating wave propagation through an elastic matrix with embedded resonating units, and nanometer motions of an extracellular tissue found in the inner ear demonstrating a mechanism of frequency separation in hearing. In these instances, the motion microscope uncovers hidden dynamics over a variety of length scales, leading to the discovery of previously unknown phenomena.
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Procesamiento de Imagen Asistido por Computador/métodos , Microscopía/métodos , Grabación en Video , Rayos Láser , Movimiento (Física)RESUMEN
Spectraplakins are multifunctional cytoskeletal linker proteins that act as important communicators, connecting cytoskeletal components with each other and to cellular junctions. Bullous pemphigoid antigen 1 (BPAG1)/dystonin is a member of spectraplakin family and expressed in various tissues. Alternative splicing of BPAG1 gene produces various isoforms with unique structure and domains. BPAG1 plays crucial roles in numerous biological processes, such as cytoskeleton organization, cell polarization, cell adhesion, and cell migration as well as signaling transduction. Genetic mutation of BPAG1 isoforms is the miscreant of epidermolysis bullosa and multifarious, destructive neurological diseases. In this review, we summarize the recent advances of BPAG1's role in various biological processes and in skin and neurological diseases.
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Distonina/metabolismo , Enfermedades del Sistema Nervioso/metabolismo , Enfermedades de la Piel/metabolismo , Animales , Distonina/química , Distonina/genética , Humanos , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Distribución TisularRESUMEN
We investigate via a combination of experiments and numerical analyses the collision of elastic vector solitons in a chain of rigid units connected by flexible hinges. Because of the vectorial nature of these solitons, very unusual behaviors are observed: while, as expected, the solitons emerge unaltered from the collision if they excite rotations of the same direction, they do not penetrate each other and instead repel one another if they induce rotations of the opposite direction. Our analysis reveals that such anomalous collisions are a consequence of the large-amplitude characteristics of the solitons, which locally modify the properties of the underlying media. Specifically, their large rotations create a significant barrier for pulses that excite rotations of the opposite direction and this may block their propagation. Our findings provide new insights into the collision dynamics of elastic solitary waves. Furthermore, the observed anomalous collisions pave new ways towards the advanced control of large amplitude mechanical pulses, as they provide opportunities to remotely detect, change, or destruct high-amplitude signals and impacts.
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We demonstrate both numerically and experimentally that geometric frustration in two-dimensional periodic acoustic networks consisting of arrays of narrow air channels can be harnessed to form band gaps (ranges of frequency in which the waves cannot propagate in any direction through the system). While resonant standing wave modes and interferences are ubiquitous in all the analyzed network geometries, we show that they give rise to band gaps only in the geometrically frustrated ones (i.e., those comprising of triangles and pentagons). Our results not only reveal a new mechanism based on geometric frustration to suppress the propagation of pressure waves in specific frequency ranges but also open avenues for the design of a new generation of smart systems that control and manipulate sound and vibrations.
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We report a new type of phononic crystals with topologically nontrivial band gaps for both longitudinal and transverse polarizations, resulting in protected one-way elastic edge waves. In our design, gyroscopic inertial effects are used to break the time-reversal symmetry and realize the phononic analogue of the electronic quantum (anomalous) Hall effect. We investigate the response of both hexagonal and square gyroscopic lattices and observe bulk Chern numbers of 1 and 2, indicating that these structures support single and multimode edge elastic waves immune to backscattering. These robust one-way phononic waveguides could potentially lead to the design of a novel class of surface wave devices that are widely used in electronics, telecommunication, and acoustic imaging.
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We report a new class of tunable and switchable acoustic metamaterials comprising resonating units dispersed into an elastic matrix. Each resonator consists of a metallic core connected to the elastomeric matrix through elastic beams, whose buckling is intentionally exploited as a novel and effective approach to control the propagation of elastic waves. We first use numerical analysis to show the evolution of the locally resonant band gap, fully accounting for the effect of nonlinear pre-deformation. Then, we experimentally measure the transmission of vibrations as a function of the applied loading in a finite-size sample and find excellent agreement with our numerical predictions. The proposed concept expands the ability of existing acoustic metamaterials by enabling tunability over a wide range of frequencies. Furthermore, we demonstrate that in our system the deformation can be exploited to turn on or off the band gap, opening avenues for the design of adaptive switches.
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Acústica/instrumentación , Modelos Teóricos , Silicio/química , SonidoRESUMEN
Exploring excellent non-noble bifunctional electrocatalysts for freshwater/seawater splitting at high current densities has attracted extensive interest owing to strong anodic oxidation and severe chloride corrosion challenges. Herein, hierarchical bimetal Ni-Co metaphosphate/molybdenum oxide heterostructure nanowires (NiCoMoPO) are rationally designed and fabricated to efficiently boost oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline freshwater/seawater, where the favorable electronic structure from heterostructures, signified by X-ray absorption spectra, endows NiCoMoPO with the enhanced intrinsic activity, while its hierarchical nanowire structure and heterostructures provide abundant active sites. Additionally, the PO3 - improves the chloride-corrosion resistance and efficiently facilitates the OER kinetics verified by theoretical and experimental studies. Therefore, NiCoMoPO drives 1000 mA cm-2 at low overpotentials of 467 and 442 mV for OER and HER in alkaline freshwater respectively, as well as a small cell voltage of 2.135 V for overall freshwater splitting with robust durability of 300 h. Impressively, due to the strong corrosion resistance, at 500 mA cm-2 of overall seawater splitting, NiCoMoPO maintains almost 2.096 V for 1200 h, indicating promising practical applications. This work sheds light on the rational design and fabrication of outstanding electrocatalysts at high current densities of seawater/freshwater splitting.
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Background: Considerable research has shown that ethnic trust reflects the existence of friendly relations among all ethnic groups and ethnic individuals, and can help in resolving ethnic conflicts and contradictions, promoting exchanges among various ethnic groups, which is highly relevant to social stability. Methods: This research, including three studies, aimed to explore the conceptual structure of ethnic trust in China, and develop and validate a measurement of the ethnic trust scale. In the first study, we used free association and in-depth interview methodology, applied cluster analysis, multidimensional scaling analysis, and grounded theory to construct the theoretical framework of Chinese people's ethnic trust concept. In the second study, we constructed an initial inventory based on the concept dimensions of ethnic trust established in the first study. We screened items by item analysis and extracted common factors using exploratory factor analysis (EFA), thus determining a total of 48 items in the two subscales (interpersonal-oriented ethnic trust subscale and the intergroup-oriented subscale), which consisted of two dimensions including particular trust and universal trust. In the third study, we used first-and second-order confirmatory factor analysis (CFA) to test the scale's construct validity. Results: The results indicated a good fit between the two-factor model and the data. And the ethnic trust scale showed very good internal consistency (Cronbach alpha >0.89) and test-retest reliability >0.70. Discussion: Based on our results, have formed a ethnic trust scale by keeping 48 items, which can beused to measure the levels of interpersonal-oriented and group-oriented ethnic trust within the Chinese cultural context.
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Emerging adulthood is the youth trajectory characterized by self-focus, identity exploration, feeling between adolescence and adulthood, instability, and experimentation. This trajectory was first identified in industrialized individualistic countries with gender equality and technological progress. To measure transition to adulthood, the Inventory of the Dimensions of Emerging Adulthood (IDEA) was created. Although emerging adulthood is considered universal, adaptations of the questionnaire across the 12 countries show different patterns, and its cross-cultural invariance has been underinvestigated. This study tests IDEA in three collectivistic countries - Armenia, China, and Russia. The sample consisted of 868 students (total male - 152, total female - 716) aged 18 to 29 years old. We tested the questionnaire separately in the three countries to check that this model fits, but we failed to prove it. After that we used a factor-analytic approach to find a common version for the three countries. We got a five-factor correlated model in accordance with the theory, but it was reduced from 31 items to 21, and three items moved to other factors. Finally, we provided measurement invariance and reached configural level. To test the narrower facets of factors we used multi-group alignment and found that variances in six parameters differ, mainly in Instability. Despite the difference in the questionnaire items, we proposed a common model for three countries that we called questionnaire IDEA-collectivistic countries (IDEA-CC).