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1.
Nano Lett ; 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619226

RESUMEN

Halide perovskite-based resistive switching memory (memristor) has potential in an artificial synapse. However, an abrupt switch behavior observed for a formamidinium lead triiodide (FAPbI3)-based memristor is undesirable for an artificial synapse. Here, we report on the δ-FAPbI3/atomic-layer-deposited (ALD)-SnO2 bilayer memristor for gradual analogue resistive switching. In comparison to a single-layer δ-FAPbI3 memristor, the heterojunction δ-FAPbI3/ALD-SnO2 bilayer effectively reduces the current level in the high-resistance state. The analog resistive switching characteristics of δ-FAPbI3/ALD-SnO2 demonstrate exceptional linearity and potentiation/depression performance, resembling an artificial synapse for neuromorphic computing. The nonlinearity of long-term potentiation and long-term depression is notably decreased from 12.26 to 0.60 and from -8.79 to -3.47, respectively. Moreover, the δ-FAPbI3/ALD-SnO2 bilayer achieves a recognition rate of ≤94.04% based on the modified National Institute of Standards and Technology database (MNIST), establishing its potential in an efficient artificial synapse.

2.
Int J Clin Pract ; 2022: 6414247, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35685497

RESUMEN

Background: This study aimed to evaluate the injury mechanism of medial epicondylar fractures in children and adolescents and its association with increased carrying angle (CA) as a predisposing factor. Materials and Methods: We evaluated 37 patients with medial epicondylar fractures who were surgically treated at our institution. Medical records and plain radiographs were reviewed to determine the mechanism of injury and the humerus-elbow-wrist angle (HEWA) and CA of the uninjured arm. To evaluate the effect of coronal alignment on specific fracture type, we compared the CA and HEWA of the 23 patients with medial epicondylar fracture who were injured by falling onto an outstretched hand (group I) with age- and sex-matched controls of 23 patients who had sustained extension-type supracondylar fractures (group II). Results: The mean age at injury was 11.7 ± 2.8 years (range, 5 to 16 years). Of the 37 patients, 23 (62.2%) recalled the injury mechanism as falling onto an outstretched hand and 10 patients (27.0%) were injured while arm wrestling, and in one patient (2.7%), the injury was associated with elbow dislocation. In the case-matched analysis, the mean HEWA of group I was 13.1 ± 2.8° (range, 7.1° to 19.8°) and the mean CA was 17.7 ± 2.7° (range, 13.0° to 22.2°). These angles were significantly increased in group I (p=0.003 and p=0.001, respectively). Conclusion: Falling onto an outstretched hand is the most common injury mechanism in patients with medial epicondylar fractures, and these fractures are associated with an increased CA.


Asunto(s)
Lesiones de Codo , Articulación del Codo , Fracturas del Húmero , Adolescente , Niño , Articulación del Codo/diagnóstico por imagen , Articulación del Codo/cirugía , Humanos , Fracturas del Húmero/diagnóstico por imagen , Fracturas del Húmero/cirugía , Radiografía , Rango del Movimiento Articular , Estudios Retrospectivos , Resultado del Tratamiento
3.
Int J Clin Pract ; 2022: 4410032, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35821700

RESUMEN

Background: Although it is generally agreed that vitamin D is important for bone health, the role of vitamin D in preventing fractures in children and adolescents remains unclear. Therefore, this study aimed to investigate the prevalence of vitamin D deficiency and insufficiency in healthy Korean children with fractures. Our secondary aim was to compare serum vitamin D levels before and during the coronavirus disease 2019 (COVID-19) outbreak. Methods: We evaluated 334 patients with fractures who were surgically treated at our institution between 2018 and 2019 before the onset of COVID-19 (group I). In addition, we collected data on the serum 25(OH)D levels of 210 patients who visited our pediatric department for evaluation of short stature (group II) and the serum 25(OH)D levels of the patients with fractures during the COVID-19 pandemic period (group III). A serum 25(OH)D level of <20 ng/mL was considered deficient, between 20 and 32 ng/mL was insufficient, and ≥32 ng/mL was considered sufficient. Results: The mean age was 8.1 ± 3.5 years in group I, 8.2 ± 3.7 years in group II, and 8.6 ± 3.5 years in group III. The prevalence of vitamin D deficiency was 53.0% in group I and 32.9% in group II. The mean serum 25(OH)D level was lower in group I than in group II (20.0 ± 7.3 ng/ml vs. 23.2 ± 6.9 ng/ml, p < 0.001). The mean serum 25(OH)D level of younger patients (<10 years) in group III was lower than that of the younger patients in the prepandemic period (21.4 ± 7.2 ng/mL vs. 19.2 ± 6.8 ng/mL, p=0.037). Conclusions: We observed a high prevalence of vitamin D deficiency/insufficiency in children with fractures who required surgical treatment. During the COVID-19 pandemic, the serum vitamin D levels became even lower, especially in younger children.


Asunto(s)
COVID-19 , Fracturas Óseas , Deficiencia de Vitamina D , Adolescente , COVID-19/complicaciones , COVID-19/epidemiología , Niño , Preescolar , Brotes de Enfermedades , Fracturas Óseas/epidemiología , Humanos , Pandemias , Prevalencia , Vitamina D , Deficiencia de Vitamina D/complicaciones , Deficiencia de Vitamina D/epidemiología
4.
BMC Plant Biol ; 19(1): 602, 2019 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-31888479

RESUMEN

BACKGROUND: Exposure of plants to different environmental insults instigates significant changes in the cellular redox tone driven in part by promoting the production of reactive nitrogen species. The key player, nitric oxide (NO) is a small gaseous diatomic molecule, well-known for its signaling role during stress. In this study, we focused on abscisic acid (ABA) metabolism-related genes that showed differential expression in response to the NO donor S-nitroso-L-cysteine (CySNO) by conducting RNA-seq-based transcriptomic analysis. RESULTS: CySNO-induced ABA-related genes were identified and further characterized. Gene ontology terms for biological processes showed most of the genes were associated with protein phosphorylation. Promoter analysis suggested that several cis-regulatory elements were activated under biotic and/or abiotic stress conditions. The ABA biosynthetic gene AtAO3 was selected for validation using functional genomics. The loss of function mutant atao3 was found to differentially regulate oxidative and nitrosative stress. Further investigations for determining the role of AtAO3 in plant defense suggested a negative regulation of plant basal defense and R-gene-mediated resistance. The atao3 plants showed resistance to virulent Pseudomonas syringae pv. tomato strain DC3000 (Pst DC3000) with gradual increase in PR1 gene expression. Similarly, atao3 plants showed increased hypersensitive response (HR) when challenged with Pst DC3000 (avrB). The atgsnor1-3 and atsid2 mutants showed a susceptible phenotype with reduced PR1 transcript accumulation. Drought tolerance assay indicated that atao3 and atnced3 ABA-deficient mutants showed early wilting, followed by plant death. The study of stomatal structure showed that atao3 and atnced3 were unable to close stomata even at 7 days after drought stress. Further, they showed reduced ABA content and increased electrolyte leakage than the wild-type (WT) plants. The quantitative polymerase chain reaction analysis suggested that ABA biosynthesis genes were down-regulated, whereas expression of most of the drought-related genes were up-regulated in atao3 than in WT. CONCLUSIONS: AtAO3 negatively regulates pathogen-induced salicylic acid pathway, although it is required for drought tolerance, despite the fact that ABA production is not totally dependent on AtAO3, and that drought-related genes like DREB2 and ABI2 show response to drought irrespective of ABA content.


Asunto(s)
Ácido Abscísico/metabolismo , Aldehído Oxidasa/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Cisteína/análogos & derivados , Regulación de la Expresión Génica de las Plantas , Óxido Nítrico/metabolismo , S-Nitrosotioles/metabolismo , Aldehído Oxidasa/metabolismo , Arabidopsis/genética , Arabidopsis/inmunología , Proteínas de Arabidopsis/metabolismo , Cisteína/metabolismo , Transducción de Señal
5.
Radiology ; 290(1): 238-243, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30226454

RESUMEN

Purpose To evaluate the safety and effectiveness of percutaneous transcholecystic removal of common bile duct (CBD) stones in 114 patients. Materials and Methods This retrospective study was approved by the institutional review board. From September 2011 through February 2017, 114 consecutive patients (68 men, 46 women; mean age, 73 years) underwent percutaneous transcholecystic removal of CBD stones. All patients had acute cholangitis or cholecystitis. Stones were extracted through a 12-F sheath by using a Wittich nitinol stone basket uder fluoroscopic guidance. Technical success rates, complications, and long-term follow-up were evaluated. Results Technical success was achieved in 96 of 114 (84.2%) patients. In 18 patients, stone removal was unsuccessful due to failure of cystic duct cannulation (n = 11), proximal migration of the CBD stone (n = 3), multiple CBD stones (n = 3), and low insertion of the cystic duct (n = 1). No major procedure-related complications were seen. During the mean follow-up of 644 days (range, 11-2206 days), CBD stones recurred in 12 patients after a mean of 884 days (range, 439-1799 days) after the procedure. Conclusion Percutaneous transcholecystic removal of common bile duct stones seems to be a safe and effective method. © RSNA, 2018 Online supplemental material is available for this article . See also the editorial by vanSonnenberg and Panchanathan in this issue.


Asunto(s)
Colecistectomía/métodos , Coledocolitiasis/cirugía , Conducto Colédoco/cirugía , Cálculos Biliares/cirugía , Anciano , Anciano de 80 o más Años , Colangiografía , Colangitis/diagnóstico por imagen , Colangitis/cirugía , Colecistectomía/efectos adversos , Colecistectomía/estadística & datos numéricos , Coledocolitiasis/diagnóstico por imagen , Conducto Colédoco/diagnóstico por imagen , Femenino , Cálculos Biliares/diagnóstico por imagen , Humanos , Masculino , Complicaciones Posoperatorias , Radiografía Intervencional , Recurrencia , Estudios Retrospectivos , Resultado del Tratamiento
6.
Int J Mol Sci ; 20(2)2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30669402

RESUMEN

Populus davidiana, native to Korea and central Asian countries, is a major contributor to the Korean forest cover. In the current study, using high-throughput RNA-seq mediated transcriptome analysis, we identified about 87 P. davidiana WRKY transcription factors (PopdaWRKY TFs) that showed differential expression to dehydration stress in both sensitive and tolerant cultivars. Our results suggested that, on average, most of the WRKY genes were upregulated in tolerant cultivars but downregulated in sensitive cultivars. Based on protein sequence alignment, P. davidiana WRKYs were classified into three major groups, I, II, III, and further subgroups. Phylogenetic analysis showed that WRKY TFs and their orthologs in Arabidopsis and rice were clustered together in the same subgroups, suggesting similar functions across species. Significant correlation was found among qRT-PCR and RNA-seq analysis. In vivo analysis using model plant Arabidopsis showed that atwrky62 (orthologous to Potri.016G137900) knockout mutants were significantly sensitive to dehydration possibly due to an inability to close their stomata under dehydration conditions. In addition, a concomitant decrease in expression of ABA biosynthetic genes was observed. The AtHK1 that regulates stomatal movement was also downregulated in atwrky62 compared to the wild type. Taken together, our findings suggest a regulatory role of PopdaWRKYs under dehydration stress.


Asunto(s)
Deshidratación/genética , Populus/genética , Populus/metabolismo , Estrés Fisiológico/genética , Factores de Transcripción/metabolismo , Transcriptoma , Adaptación Biológica , Secuencia de Aminoácidos , Mapeo Cromosómico , Biología Computacional/métodos , Secuencia Conservada , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Ontología de Genes , Fenotipo , Filogenia , Proteínas de Plantas , Transducción de Señal
7.
J Relig Health ; 57(2): 551-560, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29188547

RESUMEN

Human beings inevitably experience anxiety but attempt to avoid facing it through various forms of self-deception. This avoidance can lead to pathological symptoms. Young and middle-aged adults may be especially susceptible to suffering from anxiety because they are often single-mindedly pursuing means of achieving security. For these and others who fail to embrace life with warm enthusiasm, humor can serve to alleviate stress. This article views humor as a characteristic disposition of older adults-their humor signifying a sense of integrity and wisdom that often accompanies the aging process. Humor binds together feelings of despair and joy and contributes to a faithful reframing of faith and life. This article proposes that individuals acquire humor by perceiving the world as if on a journey to an exotic new place, seeing with new eyes even the most mundane of everyday objects and events. This capacity to perceive beauty in the ordinary world reflects a wisdom of older adults potentially available even to the young.


Asunto(s)
Adaptación Psicológica , Conducta de Elección , Terapias Complementarias , Ingenio y Humor como Asunto , Anciano , Humanos , Persona de Mediana Edad , Estrés Psicológico
8.
Eur Radiol ; 27(10): 4291-4297, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28349279

RESUMEN

OBJECTIVES: To evaluate predictive factors for false-negative diagnosis of percutaneous forceps biopsies in patients suspected of having a malignant biliary obstruction METHODS: Two hundred seventy one consecutive patients with obstructive jaundice underwent percutaneous forceps biopsy. In each patient, three to five specimens (mean, 3.5 specimens) were collected from the lesion. The final diagnosis for each patient was confirmed with pathologic findings at surgery, additional histocytologic data, or clinical and radiologic follow-up. Univariate and multivariate logistic regression analysis was used to identify risk factors associated with false-negative diagnosis. RESULTS: One hundred ninety four of 271 biopsies resulted in correct diagnoses of malignancy, while 20 biopsy diagnoses were proved to be true-negative. There were 57 false-negative diagnoses and no false-positive diagnoses. The diagnostic performance of transluminal forceps biopsy in malignant biliary obstructions was as follows: sensitivity, 77.2%; specificity, 100%; and accuracy, 78.9%; positive predictive value, 100%, negative predictive value; 25.9%. Periampullary segment of common bile duct, intrahepatic bile duct and metastatic disease were the significant risk factors of false-negative diagnosis. CONCLUSIONS: Percutaneous forceps biopsy provides relatively high accuracy in the diagnosis of malignant biliary obstructions. The predictive factors of false-negative biopsy were determined to be biopsy site and origin of primary tumour. KEY POINTS: • Percutaneous forceps biopsy provides relatively high accuracy in diagnosis of malignant biliary obstructions. • The predictive factors of false-negative biopsy were biopsy site and origin of primary tumour. • The procedure-related complications were low.


Asunto(s)
Neoplasias de los Conductos Biliares/diagnóstico , Biopsia/métodos , Colangiocarcinoma/diagnóstico , Colestasis Intrahepática/diagnóstico , Instrumentos Quirúrgicos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de los Conductos Biliares/complicaciones , Conductos Biliares Intrahepáticos/patología , Colangiocarcinoma/complicaciones , Conducto Colédoco/patología , Reacciones Falso Negativas , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Factores de Riesgo , Sensibilidad y Especificidad
9.
J Epidemiol ; 27(6): 258-264, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28314637

RESUMEN

BACKGROUND: The relation of income and socioeconomic status with suicide rates remains unclear. Most previous studies have focused on the relationship between suicide rates and macroeconomic factors (e.g., economic growth rate). Therefore, we aimed to identify the relationship between individuals' socioeconomic position and suicide risk. METHODS: We analyzed suicide mortality rates across socioeconomic positions to identify potential trends using observational data on suicide mortality collected between January 2003 and December 2013 from 1,025,340 national health insurance enrollees. We followed the subjects for 123.5 months on average. Socioeconomic position was estimated using insurance premium levels. To examine the hazard ratios of suicide mortality in various socioeconomic positions, we used Cox proportional hazard models. RESULTS: We found that the hazard ratios of suicide showed an increasing trend as socioeconomic position decreased. After adjusting for gender, age, geographic location, and disability level, Medicaid recipients had the highest suicide hazard ratio (2.28; 95% CI, 1.87-2.77). Among the Medicaid recipients, men had higher hazard ratios than women (2.79; 95% CI, 2.17-3.59 vs. 1.71; 95% CI, 1.25-2.34). Hazard ratios also varied across age groups. The highest hazard ratio was found in the 40-59-year-old group (3.19; 95% CI, 2.31-4.43), whereas the lowest ratio was found in those 60 years and older (1.44; 95% CI, 1.09-1.87). CONCLUSIONS: Our results illuminate the relationship between socioeconomic position and suicide rates and can be used to design and implement future policies on suicide prevention.


Asunto(s)
Renta/estadística & datos numéricos , Suicidio/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , República de Corea/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Clase Social , Adulto Joven
10.
New Phytol ; 211(2): 516-26, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26916092

RESUMEN

Nitric oxide (NO) is emerging as a key regulator of diverse plant cellular processes. A major route for the transfer of NO bioactivity is S-nitrosylation, the addition of an NO moiety to a protein cysteine thiol forming an S-nitrosothiol (SNO). Total cellular levels of protein S-nitrosylation are controlled predominantly by S-nitrosoglutathione reductase 1 (GSNOR1) which turns over the natural NO donor, S-nitrosoglutathione (GSNO). In the absence of GSNOR1 function, GSNO accumulates, leading to dysregulation of total cellular S-nitrosylation. Here we show that endogenous NO accumulation in Arabidopsis, resulting from loss-of-function mutations in NO Overexpression 1 (NOX1), led to disabled Resistance (R) gene-mediated protection, basal resistance and defence against nonadapted pathogens. In nox1 plants both salicylic acid (SA) synthesis and signalling were suppressed, reducing SA-dependent defence gene expression. Significantly, expression of a GSNOR1 transgene complemented the SNO-dependent phenotypes of paraquat resistant 2-1 (par2-1) plants but not the NO-related characters of the nox1-1 line. Furthermore, atgsnor1-3 nox1-1 double mutants supported greater bacterial titres than either of the corresponding single mutants. Our findings imply that GSNO and NO, two pivotal redox signalling molecules, exhibit additive functions and, by extension, may have distinct or overlapping molecular targets during both immunity and development.


Asunto(s)
Arabidopsis/metabolismo , Óxido Nítrico/metabolismo , Inmunidad de la Planta , S-Nitrosoglutatión/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Resistencia a la Enfermedad/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Prueba de Complementación Genética , Homeostasis , Modelos Biológicos , Mutación/genética , Fenotipo , Plantas Modificadas Genéticamente , Pseudomonas syringae/fisiología
11.
J Shoulder Elbow Surg ; 25(5): 723-9, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26794853

RESUMEN

BACKGROUND: Real-time sonoelastography can be used to assess tissue elasticity. The present study evaluated the relationship between tendon stiffness on sonoelastography and the magnetic resonance imaging (MRI) tendinosis grade in patients with rotator cuff tendinopathy. METHODS: The study included 39 patients with chronic pain and no history of trauma or rotator cuff tear. The supraspinatus tendons were graded according to MRI findings (grade 0, normal; grade 1, mild tendinosis; grade 2, moderate tendinosis; grade 3, marked tendinosis), and the subcutaneous fat-to-tendon (Fat/T) and gel pad-to-tendon (Pad/T) strain ratios were assessed. We used the trend test to analyze the relationship of the MRI grade with the Fat/T strain ratio and the Pad/T strain ratio. RESULTS: Of the 39 patients, 9 had grade 0, 17 had grade 1, 12 had grade 2, and 1 had grade 3 tendinosis. The mean real-time elastography Fat/T and Pad/T strain ratios were 2.92 ± 2.13 and 20.77 ± 21.78 in patients with grade 0 tendinosis, 4.08 ± 4.09 and 21.78 ± 17.16 in patients with grade 1 tendinosis, 13.48 ± 10.19 and 83.00 ± 48.26 in patients with grade 2 tendinosis, and 12.3 ± 0.00 and 16.58 ± 0.00 in patients with grade 3 tendinosis, respectively. The Fat/T and Pad/T strain ratios were positively associated with the MRI grade (P <.001). CONCLUSION: The MRI tendinosis grade is associated with stiffness assessed using sonoelastography in patients with rotator cuff tendinopathy. Therefore, sonoelastography might be a useful diagnostic tool for supraspinatus tendinopathy. LEVEL OF EVIDENCE: Level III; Diagnostic Study.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Imagen por Resonancia Magnética , Manguito de los Rotadores/diagnóstico por imagen , Tendinopatía/diagnóstico por imagen , Adulto , Dolor Crónico/etiología , Elasticidad , Diagnóstico por Imagen de Elasticidad/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Manguito de los Rotadores/fisiopatología , Índice de Severidad de la Enfermedad , Grasa Subcutánea/diagnóstico por imagen , Tendinopatía/complicaciones
12.
Cell Tissue Res ; 355(2): 337-44, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24346683

RESUMEN

We study the efficacy of bone regeneration by using two differently sized allogeneic cancellous bone granules loaded with autologous cultured osteoblasts in a rabbit model. Critical-sized bone defects of the radial shaft were made in 40 New Zealand White rabbits. Small allogeneic bone granules (150-300 µm in diameter) loaded with cultured differentiated autologous osteoblasts were implanted into one forearm (SBG group) and large bone granules (500-710 µm) loaded with osteoblasts were implanted into the forearm of the other side (LBG group). Radiographic evaluations were performed at 3, 6, 9 and 12 weeks and histology and micro-CT image analysis were carried out at 6 and 12 weeks post-implantation. On radiographic evaluation, the LBG group showed a higher bone quantity index at 3 and 6 weeks post-implantation (P < 0.05) but statistical significance was lost at 9 and 12 weeks. The progression of biological processes of the SBG group was faster than that of the LBG group. On micro-CT image analysis, the LBG group revealed a higher total bone volume and surface area than the SBG group at 6 weeks (P < 0.05) but the difference decreased at 12 weeks and was without statistical significance. Histological evaluation also revealed faster progression of new bone formation and maturation in the SBG group. Thus, the two differently sized allogeneic bone granules loaded with co-cultured autologous osteoblasts show no differences in the amount of bone regeneration, although the SBG group exhibits faster progression of bone regeneration and remodeling. This method might therefore provide benefits, such as a short healing time and easy application in an injectable form, in a clinical setting.


Asunto(s)
Huesos/anatomía & histología , Diferenciación Celular , Osteoblastos/citología , Osteogénesis , Animales , Densidad Ósea , Regeneración Ósea , Huesos/diagnóstico por imagen , Calcificación Fisiológica , Células Cultivadas , Masculino , Tamaño de los Órganos , Conejos , Trasplante Autólogo , Trasplante Homólogo , Microtomografía por Rayos X
13.
Nanoscale ; 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39011606

RESUMEN

It is critical to design bifunctional passivation molecules to simultaneously passivate the charge transport layer and perovskite layer at the charge transport layer/perovskite interface in perovskite solar cells (PSCs). In this study, we investigate the effect of para-substituted benzoic acid with different Hammett constants (σ) on the photovoltaic performance of PSCs. Two passivation molecules 4-aminomethylbenzoic acid (4-AMBA) and 4-sulfamoylbenzoic acid (4-SABA) are used to passivate the SnO2 surface with carboxylic acid and the perovskite with para-substituent electron-donating -CH2NH2 (σ = ca. -0.02) and electron-withdrawing -SO2NH2 (σ = ca. +0.60). Compared with non-passivated PSC, the passivation improves the power conversion efficiency (PCE) mainly due to the increased open-circuit voltage (VOC) and fill factor (FF), where the -SO2NH2 substituent is better in improving the photovoltaic performance than the -CH2NH2 one. The trap density is more reduced and the charge extraction ability is more improved by 4-SABA than by 4-AMBA, which indicates that the weak electron-withdrawing nature of a para-substituent such as -SO2NH2 is better for the passivation of the bottom perovskite than a weak electron-donating -CH2NH2 substituent. Consequently, the passivation with 4-SABA enhances the PCE from 22.27% to 23.64%, along with improved long-term stability. This work highlights for the first time the role of the Hammett constant in the surface passivation of PSCs.

14.
ACS Appl Mater Interfaces ; 16(25): 32147-32159, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38864112

RESUMEN

The organic molecular 2,2',7,7'-tetrakis(4,4'-dimethoxy-3-methyldiphenylamino)-9,9'-spirobifluorene (Spiro-MeOTAD) is known as a typical hole transport material in the development of an all-solid-state perovskite solar cell (PSC). Spiro-MeOTAD requires additives of lithium bifurflimide (LiTFSI) and 4-tert-butylpyridine (tBP) to increase the conductivity and solubility for enhancing the photovoltaic performance of PSCs. However, those additives have an adverse effect on the thermal stability. We report on the origin of instability of additive-containing Spiro-MeOTAD at 85 °C and the methodology to solve the thermal instability. We have found that the interaction of LiTFSI with the underneath perovskite surface facilitated by diffusive tBP is responsible for thermal degradation. Degasification of tBP from the Spiro-MeOTAD film is found to be the key to achieving thermally stable PSCs, where the optimal degassing process achieves 90% of the initial power conversion efficiency (PCE) at 85 °C after 1000 h.

15.
Nanoscale ; 15(10): 5044-5052, 2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36804638

RESUMEN

Low-temperature processed SnO2 is a promising electron transporting layer in perovskite solar cells (PSCs) due to its optoelectronic advantage. Atomic layer deposition (ALD) is suitable for forming a conformal SnO2 layer on a high-haze substrate. However, oxygen vacancy formed by the conventional ALD process using H2O might have a detrimental effect on the efficiency and stability of PSCs. Here, we report on the photovoltaic performance and stability of PSCs based on the ALD-SnO2 layer with low oxygen vacancies fabricated via H2O2. Compared to the ALD-SnO2 layer formed using H2O vapors, the ALD-SnO2 layer prepared via H2O2 shows better electron extraction due to a reduced oxygen vacancy associated with the highly oxidizing nature of H2O2. As a result, the power conversion efficiency (PCE) is enhanced from 21.42% for H2O to 22.34% for H2O2 mainly due to an enhanced open-circuit voltage. Operational stability is simultaneously improved, where 89.3% of the initial PCE is maintained after 1000 h under an ambient condition for the H2O2-derived ALD SnO2 as compared to the control device maintaining 72.5% of the initial PCE.

16.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37540122

RESUMEN

This paper describes the characteristics of a plasma-based pressure pulse generator and its potential use as a simulator for studying pellet-cladding mechanical interaction (PCMI) during reactivity-initiated accidents (RIAs). In this device, a transient pressure pulse is generated by rapid heating and expansion of hot, dense plasma inside a nuclear fuel cladding. Thus, the parameters of a pressure pulse, such as peak pressure and pressure rise-rate, can be controlled by modifying the electrical parameters of a pulse discharge circuit. The pulse discharge circuit utilizes a capacitor bank comprising several energy storage capacitors connected in parallel and a high-power solid-state switch. A pressure loading system is attached as a load to the pulse discharge circuit. The power and energy delivered to the load are calculated by measuring the voltage and current waveforms at one end of the loading system. A piezoelectric sensor is connected at the other end of the loading system to simultaneously measure the pressure pulse inside the cladding tube. Preliminary experiments are carried out with a stainless-steel tube to characterize the performance of the device as well as with a pre-hydrided ZIRLO™ cladding tube to demonstrate the potential of the device as a simulator for studying the failure characteristics of the cladding as a result of an RIA. The high pressurization rate of the device is expected to offer unique advantages for studying the PCMI mechanism.

17.
Injury ; 54(12): 111061, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37832216

RESUMEN

BACKGROUND: Although cubital tunnel syndrome is the second most common type of compressive neuropathy in the upper extremities, the indication and optimal surgical method for recurrent or refractory cubital tunnel syndrome remains controversial. This study evaluates the functional outcomes of revision surgery for cubital tunnel syndrome. MATERIAL & METHODS: This study was a retrospective observational multicenter single-institution study including 660 patients who underwent surgery for cubital tunnel syndrome from 2010 to 2019. Among the 660 patients, 42(6.4%) received revision surgery due to remaining or recurrent symptoms confirmed with electromyography(EMG). After excluding those with concurrent elbow fracture, dislocation, osteoarthritis and wound infection, a total of 24 patients were included in the study. The patients were evaluated of disease severity, revision surgical method, time interval to recurrence, underlying diseases and postoperative functional outcomes. RESULTS: All patients received ulnar nerve subfascial anterior transposition for the initial cubital tunnel syndrome surgery. Among the 24 patients (3.7%) who received revision surgery, nine received in situ neurolysis, 12 received submuscular transposition, and three received subcutaneous transfer. 21 patients (88%) reported improved mean VAS score of 4.3, while three patients complained of remaining symptoms that did not improve even after revision surgery. The patients with remaining symptoms all had underlying diabetes mellitus and were treated with subcutaneous transfer. The difference of surgical outcomes between the in situ neurolysis group and the nerve transfer groups were non-significant (p = 0.23). The most common cause of recurrent or persistent symptoms was adhesion and fibrosis at sling area. The mean follow up period before revision surgery was 26.3 months and postoperative follow up period after revision surgery was 8.5 months. CONCLUSION: The outcomes of this study imply that in-situ neurolysis may be as effective as anterior submuscular transfer of ulnar nerve for refractory cubital tunnel syndrome after anterior subfascial transfer.


Asunto(s)
Síndrome del Túnel Cubital , Humanos , Síndrome del Túnel Cubital/cirugía , Nervio Cubital/cirugía , Estudios Retrospectivos , Descompresión Quirúrgica/métodos , Procedimientos Neuroquirúrgicos/efectos adversos
18.
J Orthop Trauma ; 37(2): e57-e62, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36084238

RESUMEN

OBJECTIVES: To determine the demographic characteristics and clinical and radiologic results of low transcondylar fractures and compare them with those of other types of distal humerus fractures using multicenter data and to suggest an optimal method for their treatment. DESIGN: Retrospective cohort study. SETTING: Tertiary-care university hospital. PATIENTS: Between 2009 and 2019, 581 patients who underwent surgery for distal humerus fractures (OTA/AO classification A1 to C3) were enrolled at 7 university-affiliated hospitals. INTERVENTION: Internal fixation of low transcondylar fractures. MAIN OUTCOME MEASURES: Demographic characteristics, including sex, age, mechanism of injury, fixation methods, and complications, were compared between low transcondylar (group A) and other distal humerus (group B) fractures. Clinical outcomes assessed included pain, stability, and range of motion. Radiographs obtained at the latest follow-up were assessed for union, delayed union, nonunion, and implant failure. RESULTS: Mean age was 62.1 ± 19.1 (range, 20-95) years, and it was higher in group A (n = 100) than in group B (n = 376). Patients in group A were predominantly women. Low-energy trauma, such as that from a simple fall, was the most common cause of fracture in group A. Both column fixation, including parallel and orthogonal double plating, was performed more commonly in group A than in group B (87.4% vs. 66.4%, P < 0.001). The nonunion rate was higher in group A, but the difference was not significant. The incidence of ulnar nerve-related symptoms was higher in group A after surgery (6.3% vs. 2.0%, P = 0.003). No significant difference in clinical outcomes was found between the groups. CONCLUSIONS: Low transcondylar fractures occurred more frequently than other distal humerus fractures in older female patients and accounted for 21% of distal humerus fractures. The incidence of ulnar nerve-related symptoms was higher in patients with low transcondylar fractures after surgery. Clinical outcomes were not inferior in patients with low transcondylar fractures. The nonunion rate in patients with low transcondylar fractures treated with double plating was 3.6%. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Fijación Interna de Fracturas , Fracturas Humerales Distales , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Placas Óseas , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Fracturas Humerales Distales/cirugía , Rango del Movimiento Articular , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
19.
Antioxidants (Basel) ; 12(5)2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37237855

RESUMEN

Nitric oxide (NO) regulates several biological and physiological processes in plants. This study investigated the role of Arabidopsis thaliana Negative Immune and Growth Regulator 1 (AtNIGR1), encoding an NAD(P)-binding Rossmann-fold superfamily, in the growth and immunity of Arabidopsis thaliana. AtNIGR1 was pooled from the CySNO transcriptome as a NO-responsive gene. Seeds of the knockout (atnigr1) and overexpression plants were evaluated for their response to oxidative [(hydrogen peroxide (H2O2) and methyl viologen (MV)] or nitro-oxidative [(S-nitroso-L-cysteine (CySNO) and S-nitroso glutathione (GSNO)] stress. Results showed that the root and shoot growth of atnigr1 (KO) and AtNIGR1 (OE) exhibited differential phenotypic responses under oxidative and nitro-oxidative stress and normal growth conditions. To investigate the role of the target gene in plant immunity, the biotrophic bacterial pathogen Pseudomonas syringae pv. tomato DC3000 virulent (Pst DC3000 vir) was used to assess the basal defense, while the Pst DC3000 avirulent (avrB) strain was used to investigate R-gene-mediated resistance and systemic acquired resistance (SAR). Data revealed that AtNIGR1 negatively regulated basal defense, R-gene-mediated resistance, and SAR. Furthermore, the Arabidopsis eFP browser indicated that the expression of AtNIGR1 is detected in several plant organs, with the highest expression observed in germinating seeds. All results put together suggest that AtNIGR1 could be involved in plant growth, as well as basal defense and SAR, in response to bacterial pathogens in Arabidopsis.

20.
Knee Surg Sports Traumatol Arthrosc ; 20(2): 378-80, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22057357

RESUMEN

Single-row fixation with two inverted mattress stitches was used to treat displaced fracture of the greater tuberosity of the proximal humerus. The inverted mattress sutures were passed through the bone-tendon junction of the fragment by suture passer and crossed over the bone fragment, locking the suture ends into the lateral cortex.


Asunto(s)
Artroscopía , Fijación Interna de Fracturas/métodos , Fracturas del Hombro/cirugía , Humanos , Técnicas de Sutura
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