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1.
J Biomed Sci ; 31(1): 30, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38500170

RESUMEN

BACKGROUND: Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI. METHODS: A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-ß)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI. RESULTS: The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-ß-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function. CONCLUSION: This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.


Asunto(s)
Lesión Pulmonar Aguda , Vesículas Extracelulares , Hiperoxia , MicroARNs , Ratas , Animales , Células Cultivadas , Hiperoxia/metabolismo , Inflamación , MicroARNs/genética , MicroARNs/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismo , Vesículas Extracelulares/fisiología , Fibrosis , Lesión Pulmonar Aguda/terapia , Lesión Pulmonar Aguda/metabolismo
2.
Appl Microbiol Biotechnol ; 108(1): 206, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38353738

RESUMEN

Plant cells serve as versatile platforms for the production of high-value recombinant proteins. This study explored the efficacy of utilizing an endogenous αAmy3 promoter for the expression of a bioactive pharmaceutical protein, specifically the mature region of human bone morphogenetic protein 2 (hBMP2m). Utilizing a refined CRISPR/Cas9-mediated intron-targeting insertion technique, which incorporates an artificial 3' splicing site upstream of the target gene, we achieved a transformation efficiency of 13.5% in rice calli that carried the rice-codon optimized mature region of hBMP2 cDNA (rhBMP2m) in the αAmy3 intron 1. Both homozygous and heterozygous rhBMP2m knock-in rice suspension cell lines were generated. These lines demonstrated the endogenous αAmy3 promoter regulated rhBMP2m mRNA and rhBMP2m recombinant protein expression, with strongly upregulation in respond to sugar depletion. The homozygous rhBMP2m knock-in cell line yielded an impressive 21.5 µg/mL of rhBMP2m recombinant protein, accounting for 1.03% of the total soluble protein. The high-yield expression was stably maintained across two generations, indicating the genetic stability of rhBMP2m gene knock-in at the αAmy3 intron 1 locus. Additionally, the rice cell-derived rhBMP2m proteins were found to be glycosylated, capable of dimer formation, and bioactive. Our results indicate that the endogenous rice αAmy3 promoter-signal peptide-based expression system is an effective strategy for producing bioactive pharmaceutical proteins. KEY POINTS: • The endogenous αAmy3 promoter-based expression system enhanced the yield of BMP2 • The increased yield of BMP2 accounted for 1.03% of the total rice-soluble proteins • The rice-produced BMP2 showed glycosylation modifications, dimer formation, and bioactivity.


Asunto(s)
Oryza , Humanos , Oryza/genética , Proteína Morfogenética Ósea 2/genética , Intrones , Proteínas Recombinantes/genética , Preparaciones Farmacéuticas
3.
BMC Musculoskelet Disord ; 25(1): 23, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166834

RESUMEN

BACKGROUND: Stable upper limb fractures, such as radius, ulna, or distal humerus fractures, are common pediatric orthopedic traumas that are traditionally managed with cast immobilization. The commonly used synthetic fiberglass cast is light and water resistant but may promote skin itchiness during casting, which is a common complaint of patients. In addition, these diisocyanate-based casts have been proven to be toxic and may cause asthma. Herein, we introduce a novel biobased polyester cast to compare its clinical outcomes and patient satisfaction with conventional synthetic fiberglass casts. METHODS: From Feb 2022 to Nov 2022, we undertook a single-center prospective randomized trial involving 100 children with cast-immobilized stable upper limb fractures. These patients were randomized into either biobased polyester or synthetic fiberglass groups. All patients were regularly followed up till the cast removal which occurred approximately 3-4 weeks after immobilizing. Objective clinical findings and subjective patient questionnaire were all collected and analyzed. RESULTS: According to the radiographs taken on the day of cast removal, there was no loss of reduction in both groups. The incidence of skin problems was 3.4 times higher in the synthetic fiberglass group than in the biobased polyester group. For the subjective questionnaire, the biobased polyester cast was preferred in every sub-item. CONCLUSIONS: Our study strongly suggested that the novel biobased polyester cast provides matching stability to conventional fiberglass casts and improves patient satisfaction in an eco-friendlier and safer way. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Registration and Results System ( https://www. CLINICALTRIALS: gov/ ; ID: NCT06102603; Date: 26/10/2023).


Asunto(s)
Fracturas del Radio , Niño , Humanos , Fracturas del Radio/terapia , Moldes Quirúrgicos/efectos adversos , Estudios Prospectivos , Extremidad Superior
4.
Alzheimer Dis Assoc Disord ; 37(1): 28-34, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36251929

RESUMEN

INTRODUCTION: The Perceived Research Burden Assessment (PeRBA) was developed to measure participant perceptions of burden in research studies. This study aimed to examine the psychometric properties of this assessment using Rasch analysis in participants in the longitudinal studies of the Alzheimer disease (AD) and their family members. METHODS: PeRBA was administered to 443 participants in studies of AD and 212 family members across 4 Alzheimer Disease Research Centers. We used Rasch analysis to examine PeRBA's psychometric properties, and data-model fit both at item and scale levels. RESULTS: PeRBA demonstrated good reliability and item and person fit for participants and family members. A few items did not fit the model for participants or family members. Areas of content redundancy were found in items assessing similar amounts of perceived research burden. Areas of content gaps were also found, with no items assessing certain levels of perceived research burden. CONCLUSION: Analysis results support the good overall psychometric properties of PeRBA among research participants in studies of AD and their family members. Recommendations have been provided to improve the assessment, including rewording items and adding items that could account for a broader range of perceived research burden.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Estudios Longitudinales
5.
Clin Exp Rheumatol ; 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37706287

RESUMEN

Inflammation-induced bone destruction is the main cause of progressive joint damage in rheumatoid arthritis (RA) and osteoarthritis (OA). In addition, depending on the tissue microenvironment stimulators, the synovium transforms into a hyperplastic invasive tissue. The synovium includes two specific subsets of fibroblasts surrounding the joints: lining and sublining synovial fibroblasts (SFs). These SFs grow and interact with immune cells invading the bone and cartilage; specifically, SFs, which are the major mesenchymal cells in the joints, develop an aggressive phenotype, thereby producing cytokines and proteases involved in arthritis pathogeneses. Transcriptomic differences in the heterogeneity of SFs reflect the joint-specific origins of the SFs interacting with immune cells. To understand the subsets of SFs that lead to joint damage in arthritis, clarifying the distinct phenotypes and properties of SFs and understanding how they influence bone cells, such as osteoclasts and chondrocytes, is crucial. This review provides an overview of the advancements in the understanding of SF subsets and features, which may aid in identifying newer therapeutic targets.

6.
BMC Geriatr ; 23(1): 663, 2023 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-37845603

RESUMEN

BACKGROUND: Responsiveness and minimal clinically important difference (MCID) are critical indices to understand whether observed improvement represents a meaningful improvement after intervention. Although simultaneous cognitive-exercise training (SCET; e.g., performing memory tasks while cycling) has been suggested to enhance the cognitive function of older adults, responsiveness and MCID have not been established. Hence, we aimed to estimate responsiveness and MCIDs of two dual task performance involving cognition and hand function in older adults with and without cognitive impairment and to compare the differences in responsiveness and MCIDs of the two dual task performance between older adults with and without cognitive impairment. METHODS: A total of 106 older adults completed the Montreal Cognitive Assessment and two dual tasks before and after SCET. One dual task was a combination of Serial Sevens Test and Box and Block Test (BBT), and the other included frequency discrimination and BBT. We used effect size and standardized response mean to indicate responsiveness and used anchor- and distribution-based approaches to estimating MCID ranges. When conducting data analysis, all participants were classified into two cognitive groups, cognitively healthy (Montreal Cognitive Assessment ≥ 26) and cognitively impaired (Montreal Cognitive Assessment < 26) groups, based on the scores of the Montreal Cognitive Assessment before SCET. RESULTS: In the cognitively healthy group, Serial Seven Test performance when tasked with BBT and BBT performance when tasked with Serial Seven Test were responsive to SCET (effect size = 0.18-0.29; standardized response mean = 0.25-0.37). MCIDs of Serial Seven Test performance when tasked with BBT ranged 2.09-2.36, and MCIDs of BBT performance when tasked with Serial Seven Test ranged 3.77-5.85. In the cognitively impaired group, only frequency discrimination performance when tasked with BBT was responsive to SCET (effect size = 0.37; standardized response mean = 0.47). MCIDs of frequency discrimination performance when tasked with BBT ranged 1.47-2.18, and MCIDs of BBT performance when tasked with frequency discrimination ranged 1.13-7.62. CONCLUSIONS: Current findings suggest that a change in Serial Seven Test performance when tasked with BBT between 2.09 and 2.36 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively healthy, and a change in frequency discrimination performance when tasked with BBT between 1.47 and 2.18 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively impaired. Clinical practitioners may use these established MCIDs of dual tasks involving cognition and hand function to interpret changes following SCET for older adults with and without cognitive impairment. TRIAL REGISTRATION: NCT04689776, 30/12/2020.


Asunto(s)
Disfunción Cognitiva , Diferencia Mínima Clínicamente Importante , Anciano , Humanos , Cognición/fisiología , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/terapia , Ejercicio Físico/psicología , Análisis y Desempeño de Tareas
7.
Cytotherapy ; 24(1): 72-85, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34696962

RESUMEN

BACKGROUND AIMS: Infrapatellar fat pad-derived mesenchymal stromal cells (IFP-MSCs) have not yet been used in a human clinical trial. In this open-label phase 1 study, patients with knee osteoarthritis (OA) received a single intra-articular injection of autologous IFP-MSCs. Safety was assessed through physical examination of the knee joint, vital signs, laboratory tests and adverse events. Efficacy was evaluated with regard to pain and function using questionnaires, x-ray and magnetic resonance imaging (MRI). Indoleamine-2,3-dioxygenase (IDO) expression in IFP-MSCs primed with interferon gamma was used as an in vitro potency measurement in investigating the correlations of clinical outcomes. METHODS: Twelve patients with symptomatic knee OA were recruited. IFP adipose tissue was harvested from each patient's knee through surgical excision for IFP-MSC manufacturing. Cryopreserved IFP-MSCs (5 × 107 cells) were injected into the knee joint immediately after thawing. RESULTS: No significant adverse events were observed. Patients who received IFP-MSCs exhibited clinically significant pain and functional improvement at 48-week follow-up. The MRI Osteoarthritis Knee Score average was also significantly reduced from 100.2 before injection to 85.0 at 48 weeks after injection. The IDO expression of the primed IFP-MSCs of the 12 patients was correlated with clinical outcomes after injection. CONCLUSIONS: A single intra-articular injection of IFP-MSCs appears to be a safe therapy for treating knee OA and may improve disease symptoms. IDO measurement of primed IFP-MSCs has potential as a potency marker of MSC products for immunomodulatory therapy.


Asunto(s)
Células Madre Mesenquimatosas , Osteoartritis de la Rodilla , Tejido Adiposo , Humanos , Inyecciones Intraarticulares , Articulación de la Rodilla , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/terapia
8.
BMC Musculoskelet Disord ; 22(1): 977, 2021 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-34814872

RESUMEN

BACKGROUND: Evans calcaneal lengthening osteotomy is used to treat symptomatic flexible flatfoot when conservative treatment fails. Grafts such as autologous iliac bone grafts, allografts, and xenografts are implanted at the osteotomy site to lengthen the lateral column of the hindfoot. This study aimed to present the outcomes of an autologous mid-fibula bone graft used for calcaneal lengthening in symptomatic pes valgus in adolescents. METHODS: We retrospectively examined 23 ft of 13 adolescents who underwent surgery between July 2014 and January 2018. The radiological and clinical outcomes (American Orthopaedic Foot and Ankle Society ankle-hindfoot scale scores) were assessed during a mean follow-up of 49.7 (range, 30.9-73.4) months. The mean distance of the lengthening site was measured to evaluate graft sinking or collapse. The Goldberg scoring system was used to determine the degree of union at the donor and recipient sites. RESULTS: The calcaneal pitch and the anteroposterior and lateral talo-first metatarsal (Meary) angles showed significant correction, from 14.4 to 19.6 (p < 0.001), and from 14.5 to 4.6 (p < 0.001) and 13.5 to 8.5 (p < 0.001), respectively. The mean distance of the lengthening site showed no significant change (p = 0.203), suggesting no graft sinking or postoperative collapse. The lateral distal tibial angle showed no significant difference (p = 0.398), suggesting no postoperative ankle valgus changes. Healing of the recipient and donor sites occurred in 23 and 21 ft, respectively. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scores improved significantly, from 68.0 to 98.5 (p < 0.001). CONCLUSIONS: Evans calcaneal lengthening using an ipsilateral mid-fibula bone autograft resulted in significant improvement in clinical and radiological outcomes without ankle valgus deformity. Hence, it could be a treatment option for lateral column calcaneal lengthening in adolescents.


Asunto(s)
Calcáneo , Pie Plano , Adolescente , Autoinjertos , Calcáneo/diagnóstico por imagen , Calcáneo/cirugía , Peroné , Pie Plano/diagnóstico por imagen , Pie Plano/cirugía , Humanos , Estudios Retrospectivos
9.
Alzheimers Dement ; 17(3): 534-542, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33215873

RESUMEN

INTRODUCTION: The Clinical Dementia Rating (CDR) is widely used in Alzheimer's disease research studies and has well established reliability and validity. To facilitate the development of an online, electronic CDR (eCDR) for more efficient clinical applications, this study aims to produce a shortened version of the CDR, and to develop the statistical model for automatic scoring. METHODS: Item response theory (IRT) was used for item evaluation and model development. An automatic scoring algorithm was validated using existing CDR global and domain box scores as the reference standard. RESULTS: Most CDR items discriminate well at mild and very mild levels of cognitive impairment. The bi-factor IRT model fits best and the shortened CDR still demonstrates very high classification accuracy (81%∼92%). DISCUSSION: The shortened version of the CDR and the automatic scoring algorithm has established a good foundation for developing an eCDR and will ultimately improve the efficiency of cognitive assessment.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Disfunción Cognitiva/diagnóstico , Pruebas de Estado Mental y Demencia , Anciano , Algoritmos , Femenino , Humanos , Masculino , Pruebas de Estado Mental y Demencia/normas , Pruebas de Estado Mental y Demencia/estadística & datos numéricos , Escalas de Valoración Psiquiátrica/normas , Escalas de Valoración Psiquiátrica/estadística & datos numéricos
10.
Nanotechnology ; 31(23): 235603, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32053797

RESUMEN

Yttrium orthovanadate (YVO4) has been widely used as a host material for low- and medium-power diode-pumped solid-state lasers due to its excellent thermal, mechanical, and optical properties. This work demonstrates the synthesis and site symmetry tunning of polycrystalline YVO4:Eu nanoparticles with uniform size and shape using a continuous-flow microreactor at high pressures. High-quality YVO4:Eu nanoparticles were created using a residence time of fewer than 20 s. Carefully controlling the heat flux and flow rate can produce the YVO4:Eu nanoparticles showing different crystallinity, crystal morphologies, site symmetry around Eu3+, and therefore optical emission. The site symmetry of YVO4:Eu is adjusted without any stoichiometric modification of the precursors by simply varying the flow rate and heat flux of the microreactor. The site symmetries of the as-synthesized YVO4:Eu nanoparticles are studied by investigating their photoluminescent emission spectra and computational model of first-principle density functional theory (DFT). The DFT model indicates that the oxygen vacancy influenced the V-O association and the overlap between Eu 4f and V 3d states which can contribute to different optical transitions and, therefore, distinct emission spectrum. The use of a continuous flow microreactor at high pressure provides better understandings of the hydrothermal syntheses of functional nanoparticles and enables scalable manufacturing concurrently.

11.
Child Care Health Dev ; 46(5): 576-584, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32599661

RESUMEN

BACKGROUND: Children with sickle cell disease (SCD) are at risk for fine motor (FM) delays; however, screening for FM impairments is not common among young children with SCD. The Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) is the most commonly used performance-based developmental assessment. We aim to determine if the FM subtest of the Bayley-III is structured hierarchically in accordance with development and comprehensively evaluates FM development in children with SCD. METHODS: Bayley-III assessments were completed between October 2009 and December 2013. The Bayley-III FM screening test, a shorter and more rapid method of assessing for FM impairments, was not directly administered to participants. Screening test scores were calculated from full Bayley-III scores. RESULTS: Rasch analysis was performed using WINSTEPS. Sixty children with SCD were included in the final Rasch model. The Rasch-generated Wright map, which jointly positions items and persons on the same latent trait, illustrated that the FM items were slightly skewed towards more challenging items, indicating more difficult items may be overrepresented. High item separation values were reported (17.4), and item outfit statistics were less than 1.7. More than one third of items demonstrated overfit, indicating possible item redundancy. The FM subtest and the screening test, a shorter and faster method of assessing skills, were highly correlated (r = 0.993, p < 0.001). CONCLUSION: The Bayley-III FM subtest is structured hierarchically, aligning with motor development, and comprehensively evaluates FM development in children with SCD. The test could be improved by reordering items, removing overfitting items and modifying screening test items to capture all ranges of development. The screening test is comprehensive and has high potential clinical utility among children with SCD.


Asunto(s)
Anemia de Células Falciformes/fisiopatología , Anemia de Células Falciformes/psicología , Trastornos de la Destreza Motora/diagnóstico , Anemia de Células Falciformes/complicaciones , Desarrollo Infantil/fisiología , Preescolar , Femenino , Humanos , Lactante , Masculino , Destreza Motora/fisiología , Trastornos de la Destreza Motora/etiología , Trastornos de la Destreza Motora/fisiopatología , Pruebas Neuropsicológicas , Valor Predictivo de las Pruebas , Psicometría , Reproducibilidad de los Resultados
12.
Angew Chem Int Ed Engl ; 59(45): 19924-19928, 2020 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-32710468

RESUMEN

Oxidative anion insertion into graphite in an aqueous environment represents a significant challenge in the construction of aqueous dual-ion batteries. In dilute aqueous electrolytes, the oxygen evolution reaction (OER) dominates the anodic current before anions can be inserted into the graphite gallery. Herein, we report that the reversible insertion of Mg-Cl superhalides in graphite delivers a record-high reversible capacity of 150 mAh g-1 from an aqueous deep eutectic solvent comprising magnesium chloride and choline chloride. The insertion of Mg-Cl superhalides in graphite does not form staged graphite intercalation compounds; instead, the insertion of Mg-Cl superhalides makes the graphite partially turbostratic.

13.
Pain Pract ; 19(6): 621-632, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30891911

RESUMEN

OBJECTIVE: To investigate whether physician-patient agreement of potential patient problem areas impacts subsequent patient enrollment in an interdisciplinary pain management program. DESIGN: Retrospective chart review of 544 patients who underwent evaluation of their chronic pain. Physicians and their patients endorsed perceived patient problems during the evaluation. The potential problems included 7 clinical domains: pain, sleep, mood, physical functioning, ability to cope with pain, ability to manage pain flare-ups, and pain medication effectiveness. RESULTS: Results indicated statistically significant levels of agreement among the physicians and their patients (free-marginal kappa range, 0.19 to 0.94, P's < 0.001). The highest agreement occurred for pain and the lowest for pain medication effectiveness. Patients who enrolled in a recommended program did not differ from those who did not enroll based on either levels of agreement or average number of physician-patient agreements for the 7 clinical domains (P's > 0.05). Patients recommended for higher-intensity programs were perceived by their evaluating physician to have a significantly greater number of problematic clinical domains than those recommended for less intense pain programs. CONCLUSION: The level of physician-patient agreement regarding the patients' current difficulties did not appear to influence patients' decisions to participate in interdisciplinary pain management. Extraneous, nonclinical factors may have had a greater impact on participation in interdisciplinary pain management than physician-patient agreement. Future research should focus on identifying these factors and their impact. Also, studying the impact of physician-patient agreement beyond enrollment status (eg, on successful program completion) may be helpful in potentially enhancing patient outcomes.


Asunto(s)
Manejo del Dolor/métodos , Participación del Paciente , Relaciones Médico-Paciente , Adulto , Dolor Crónico/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , Estudios Retrospectivos
14.
Nanotechnology ; 29(50): 505205, 2018 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-30240361

RESUMEN

Sintering of metal nanowire (NW) networks on transparent polymers is an emerging approach for fabricating transparent conductive electrodes used in multiple devices. Pulsed light sintering is a scalable sintering process in which large-area, broad-spectrum xenon lamp light causes rapid NW fusion to increase network conductivity, while embedding the NWs in the polymer to increase mechanical robustness. This paper develops a multiphysical approach for predicting evolution of conductivity, NW fusion and nanoscale temperature gradients on the substrate during pulsed light sintering of silver NWs on polycarbonate. Model predictions are successfully validated against experimentally measured temperature and electrical resistance evolution. New insight is obtained into the diameter-dependent kinetics of NW fusion and nanoscale temperature gradients on the substrate, which are difficult to obtain experimentally. These observations also lead to the understanding that NW embedding in intense pulsed light sintering (IPL) can occur below the glass transition temperature of the polymer, and to a new differential thermal expansion-based mechanism of NW embedding during IPL. These insights, and the developed model, create a framework for physics-guided choice of NWs, substrate and process parameters to control conductivity and prevent substrate damage during the process.

15.
BMC Musculoskelet Disord ; 19(1): 190, 2018 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-29885670

RESUMEN

BACKGROUND: There have been many studies regarding nongeriatric femoral neck fractures (FNFs), which included patients of a wide age range (between 20 and 60 years old). We aimed to determine whether internal fixation provided acceptable outcomes for middle-aged patients with displaced FNFs, and identify predictors of successful internal fixation. METHODS: A total of 117 patients, aged 50-60 years and who underwent closed reduction and unilateral internal fixation using cannulated screws, were included. The outcomes were classified as either "complications" (varus malunion, femoral neck shortening, non-union/early collapse, avascular necrosis, or arthroplasty during the follow-up) or "optimal outcomes" (no complications). Patients with displaced FNFs (Garden stages III-IV, n = 69) were categorized according to whether they experienced acceptable or unacceptable reduction. We evaluated whether patients' clinical characteristics could predict optimal outcomes. RESULTS: Patients with displaced FNFs generally experienced complications (84.1%). Twenty-two percent of patients experienced optimal outcomes when acceptable reduction was achieved. Patients with unacceptable reductions experienced complications. Optimal outcomes were positively associated with Pauwels' type II fracture (OR: 8.67, p = 0.025) and negatively associated with excessive alcohol consumption (p = 0.045). CONCLUSIONS: Compared with the younger age group, complication rates are higher in middle-aged patients with displaced FNFs treated using cannulated screws. If internal fixation is to be used for a displaced FNF, patient selection is essential. Care must be taken to avoid selecting patients with excessive alcohol consumption, while successful internal fixation may be more likely for patients with Pauwels' type II fracture.


Asunto(s)
Reducción Cerrada/tendencias , Fracturas del Cuello Femoral/diagnóstico por imagen , Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas/tendencias , Complicaciones Posoperatorias/diagnóstico por imagen , Factores de Edad , Reducción Cerrada/efectos adversos , Reducción Cerrada/métodos , Femenino , Fracturas del Cuello Femoral/epidemiología , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento
16.
Arch Orthop Trauma Surg ; 138(5): 623-628, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29356940

RESUMEN

INTRODUCTION: Outerbridge-Kashiwagi ulnohumeral arthroplasty is an effective method in treating elbow osteoarthritis; however, distal humerus fracture after surgery can become a critical issue. A previous biomechanical study has shown that the failure load of the distal humerus decreases after a fenestration, but the size of the fenestration hole has not yet been discussed. MATERIALS AND METHODS: 32 fresh-frozen cadaveric distal humeri were obtained. Two drill sizes were chosen for fenestration: 12 and 15 mm in diameter. Two directions of force were applied with a materials testing machine for biomechanical testing: 5° flexion for axial loading and 75° flexion for anterior-posterior (AP) loading. Each specimen randomly received one of the two fenestration sizes, and force directions. All specimens were loaded to failure at a rate of 2 mm/min. RESULTS: The failure loads of the 12 and 15 mm groups were not significantly different in either axial loading(3886 ± 1271 N vs 4286 ± 901 N) or AP loading(2303 ± 803 N vs 1897 ± 357 N). All specimens loaded with axial force failed via the fenestration holes; however, during AP loading, some specimens failed through the fenestration holes, while others at diaphysis (p = 0.28). CONCLUSIONS: The failure load of distal humeri did not differ significantly after fenestration of 12 or 15 mm. The clinical relevance is that as the risk of distal humerus fracture is not exacerbated, a larger-size fenestration hole could be of help to improve the effectiveness of this surgical procedure.


Asunto(s)
Artroplastia/métodos , Articulación del Codo/cirugía , Húmero/cirugía , Fenómenos Biomecánicos , Humanos
17.
Nanotechnology ; 28(23): 235602, 2017 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-28445169

RESUMEN

Hollow silica nanoparticles (HSNPs) were synthesized using a microreactor-assisted system with a hydrodynamic focusing micromixer. Due to the fast mixing of each precursor in the system, the poly(acrylic acid) (PAA) thermodynamic-locked (TML) conformations were protected from their random aggregations by the immediately initiated growth of silica shells. When altering the mixing time through varying flow rates and flow rate ratios, the different degrees of the aggregation of PAA TML conformations were observed. The globular and necklace-like TML conformations were successfully captured by modifying the PAA concentration at the optimized mixing condition. Uniform HSNPs with an average diameter ∼30 nm were produced from this system. COMSOL numerical models was established to investigate the flow and concentration profiles, and their effects on the formation of PAA templates. Finally, the quality and utility of these uniform HSNPs were demonstrated by the fabrication of antireflective thin films on monocrystalline photovoltaic cells which showed a 3.8% increase in power conversion efficiency.

18.
Nanotechnology ; 28(26): 26LT01, 2017 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-28524821

RESUMEN

In this letter, we present a nanophotonic device consisting of plasmonic nanopatch array (NPA) with integrated metal-organic framework (MOF) for enhanced infrared absorption gas sensing. By designing a gold NPA on a sapphire substrate, we are able to achieve enhanced optical field that spatially overlaps with the MOF layer, which can adsorb carbon dioxide (CO2) with high capacity. Experimental results show that this hybrid plasmonic-MOF device can effectively increase the infrared absorption path of on-chip gas sensors by more than 1100-fold. The demonstration of infrared absorption spectroscopy of CO2 using the hybrid plasmonic-MOF device proves a promising strategy for future on-chip gas sensing with ultra-compact size.

19.
J Med Biol Eng ; 37(1): 85-93, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28286465

RESUMEN

Autogenous bone grafting, used to repair bone defects, is limited and the donor site can experience complications. Compared to autogenous bone graft, artificial bones have different porosity, which might make them suitable alternatives to bone grafts. Here, two porous biphasic calcium phosphate bone substitutes, namely Bicera™ and Triosite™, are used in an animal study and clinical practice to find a suitable porosity for implantation. Bicera™ and Triosite™ consist of 60 wt% hydroxyapatite and 40 wt% ß-tricalcium phosphate, with the porosity of Bicera™ (82%) being higher than that of Triosite™ (70%). In the animal study, the implantation procedure was carried out on twenty-four female New Zealand rabbits. 12 weeks after implantation, the new bones were well infiltrated into the Bicera™ and Triosite™ bone grafts. In the clinical study, patients with comminuted fracture, fracture nonunion, or arthrodesis were included in the study of bone substitution with Bicera™. 27 patients underwent fracture fixation treatment. Bone healing of 22.22% (6/27) of patients happened within 3 months after the surgery, and that of 66.67% (18/27) of patients happened within 6 months. These results reveal that Bicera™ has good incorporation with host bone, and that new bone is able to grow within the porous structure, giving it high potential in the treatment of bone defects.

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