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1.
ACS Appl Mater Interfaces ; 14(21): 24073-24088, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35588005

RESUMEN

Organic-inorganic halide perovskites are well-known for their unique self-healing ability. In the presence of strong external stimuli, such as light, temperature, and moisture, high-energy defects are created which can be healed by removing the perovskite from the degradation source. This self-healing ability has been showcased in devices with recoverable performance and day-and-night cycling operation to dramatically extend the device lifetime and even mechanical durability. However, to date, the mechanistic details and theory around this captivating trait are sparse and convoluted by the complex nature of perovskites. With a clear understanding of the intrinsic self-healing property, perovskite solar cells with extended lifetimes and durability can be designed to realize the large-scale commercialization of perovskite solar cells. Here, we spotlight the relevant degradation and self-healing literature and then propose design strategies to help conceptualize future research.

3.
Aust J Gen Pract ; 51(3): 143-144, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35224575
5.
J Urol ; 207(5): 1105-1115, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34968146

RESUMEN

PURPOSE: We sought to automate R.E.N.A.L. (for radius, exophytic/endophytic, nearness of tumor to collecting system, anterior/posterior, location relative to polar line) nephrometry scoring of preoperative computerized tomography scans and create an artificial intelligence-generated score (AI-score). Subsequently, we aimed to evaluate its ability to predict meaningful oncologic and perioperative outcomes as compared to expert human-generated nephrometry scores (H-scores). MATERIALS AND METHODS: A total of 300 patients with preoperative computerized tomography were identified from a cohort of 544 consecutive patients undergoing surgical extirpation for suspected renal cancer at a single institution. A deep neural network approach was used to automatically segment kidneys and tumors, and geometric algorithms were developed to estimate components of R.E.N.A.L. nephrometry score. Tumors were independently scored by medical personnel blinded to AI-scores. AI- and H-score agreement was assessed using Lin's concordance correlation and their predictive abilities for both oncologic and perioperative outcomes were assessed using areas under the curve. RESULTS: Median age was 60 years (IQE 51-68), and 40% were female. Median tumor size was 4.2 cm and 91.3% had malignant tumors, including 27%, 37% and 24% with high stage, grade and necrosis, respectively. There was significant agreement between H-scores and AI-scores (Lin's ⍴=0.59). Both AI- and H-scores similarly predicted meaningful oncologic outcomes (p <0.001) including presence of malignancy, necrosis, and high-grade and -stage disease (p <0.003). They also predicted surgical approach (p <0.004) and specific perioperative outcomes (p <0.05). CONCLUSIONS: Fully automated AI-generated R.E.N.A.L. scores are comparable to human-generated R.E.N.A.L. scores and predict a wide variety of meaningful patient-centered outcomes. This unambiguous artificial intelligence-based scoring is intended to facilitate wider adoption of the R.E.N.A.L. score.


Asunto(s)
Inteligencia Artificial , Neoplasias Renales , Computadores , Femenino , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Neoplasias Renales/cirugía , Persona de Mediana Edad , Necrosis , Nefrectomía/métodos , Estudios Retrospectivos
6.
J Am Chem Soc ; 143(37): 15215-15223, 2021 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-34516736

RESUMEN

Controlling grain growth is of great importance in maximizing the charge carrier transport for polycrystalline thin-film electronic devices. The thin-film growth of halide perovskite materials has been manipulated via a number of approaches including solvent engineering, composition engineering, and post-treatment processes. However, none of these methods lead to large-scale atomically flat thin films with extremely large grain size and high charge carrier mobility. Here, we demonstrate a novel π-conjugated ligand design approach for controlling the thin-film nucleation and growth kinetics in two-dimensional (2D) halide perovskites. By extending the π-conjugation and increasing the planarity of the semiconducting ligand, nucleation density can be decreased by more than 5 orders of magnitude. As a result, wafer-scale 2D perovskite thin films with highly ordered crystalline structures and extremely large grain size are readily obtained. We demonstrate high-performance field-effect transistors with hole mobility approaching 10 cm2 V-1 s-1 with ON/OFF current ratios of ∼106 and excellent stability and reproducibility. Our modeling analysis further confirms the origin of enhanced charge transport and field and temperature dependence of the observed mobility, which allows for clear deciphering of the structure-property relationships in these nascent 2D semiconductor systems.

7.
Adv Mater ; 33(32): e2100791, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34219297

RESUMEN

Surface passivation is an effective way to boost the efficiency and stability of perovskite solar cells (PSCs). However, a key challenge faced by most of the passivation strategies is reducing the interface charge recombination without imposing energy barriers to charge extraction. Here, a novel multifunctional semiconducting organic ammonium cationic interface modifier inserted between the light-harvesting perovskite film and the hole-transporting layer is reported. It is shown that the conjugated cations can directly extract holes from perovskite efficiently, and simultaneously reduce interface non-radiative recombination. Together with improved energy level alignment and the stabilized interface in the device, a triple-cation mixed-halide medium-bandgap PSC with an excellent power conversion efficiency of 22.06% (improved from 19.94%) and suppressed ion migration and halide phase segregation, which lead to a long-term operational stability, is demonstrated. This strategy provides a new practical method of interface engineering in PSCs toward improved efficiency and stability.

9.
Artículo en Inglés | MEDLINE | ID: mdl-33884053

RESUMEN

At institutions with an emphasis on authentic research experiences as an integral part of the biology curriculum, COVID created a huge challenge for course instructors whose learning objectives were designed for such experiences. Moving such laboratory experiences online when remote learning became necessary has resulted in a new model for CUREs that utilizes free online databases to provide not only a novel research experience for students, but also the opportunity to engage in big data analysis. Cancer BioPortal (cBioPortal) is an open-access collective cancer research resource for storing and exploring clinical, genomic, proteomic, and transcriptomic data. cBioPortal eliminates the computational barrier of interpreting complex genomic data by providing easily understandable visualization that can be interpreted and translated into relevant biological insights. Because no prior computational knowledge is required, cBioPortal is an ideal educational tool for either in-person or distance learning environments. We developed a pedagogical approach, video tutorials, and data analysis workflows centered on using cBioPortal. Pedagogically, students develop an initial research outline that is continually updated and graded throughout the project. Progress during the project or course is assessed by a series of student presentations that are 5 to 15 minutes in length and are aimed at explaining the approach used in data acquisition, interpretation of the data, and relevance to the initial hypothesis. While cancer-specific, this analysis platform appeals to a wide range of classes and student interests. Further, the project has been successfully done both as an independent research experience and as part of a virtual class-based research project.

10.
Phys Chem Chem Phys ; 23(16): 9804-9813, 2021 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-33908508

RESUMEN

Thermal decomposition of cyclohexane at temperatures up to 1310 K was performed using flash pyrolysis coupled with vacuum ultraviolet (118.2 nm) photoionization time-of-flight mass spectrometry. The experimental results revealed that the major initiation reaction of cyclohexane decomposition was C-C bond fission leading to the formation of 1,6-hexyl diradical. The 1,6-hexyl diradical could isomerize to 1-hexene and decompose into ˙C3H7 + ˙C3H5 and ˙C4H7 + ˙C2H5. The 1,6-hexyl diradical could also undergo direct dissociation; the C4H8 fragment via the 1,4-butyl diradical intermediate was observed, serving as evidence of the 1,6-hexyl diradical mechanism. Quantum chemistry calculations at UCCSD(T)/cc-pVDZ level of theory on the initial reaction pathways of cyclohexane were performed and found to be consistent with the experimental conclusions. Cyclohexyl radical was not observed as an initial intermediate in the pyrolysis. Benzene was produced from sequential H2 eliminations of cyclohexane at high temperatures.

11.
ACS Nano ; 15(4): 6316-6325, 2021 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-33709710

RESUMEN

Two-dimensional perovskites that could be regarded as natural organic-inorganic hybrid quantum wells (HQWs) are promising for light-emitting diode (LED) applications. High photoluminescence quantum efficiencies (approaching 80%) and extremely narrow emission bandwidth (less than 20 nm) have been demonstrated in their single crystals; however, a reliable electrically driven LED device has not been realized owing to inefficient charge injection and extremely poor stability. Furthermore, the use of toxic lead raises concerns. Here, we report Sn(II)-based organic-perovskite HQWs employing molecularly tailored organic semiconducting barrier layers for efficient and stable LEDs. Utilizing femtosecond transient absorption spectroscopy, we demonstrate the energy transfer from organic barrier to inorganic perovskite emitter occurs faster than the intramolecular charge transfer in the organic layer. Consequently, this process allows efficient conversion of lower-energy emission associated with the organic layer into higher-energy emission from the perovskite layer. This greatly broadened the candidate pool for the organic layer. Incorporating a bulky small bandgap organic barrier in the HQW, charge transport is enhanced and ion migration is greatly suppressed. We demonstrate a HQW-LED device with pure red emission, a maximum luminance of 3466 cd m-2, a peak external quantum efficiency up to 3.33%, and an operational stability of over 150 h, which are significantly better than previously reported lead-free perovskite LEDs.

12.
Nat Nanotechnol ; 16(5): 584-591, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33574600

RESUMEN

Anionic diffusion in a soft crystal lattice of hybrid halide perovskites affects their stability, optoelectronic properties and the resulting device performance. The use of two-dimensional (2D) halide perovskites improves the chemical stability of perovskites and suppresses the intrinsic anionic diffusion in solid-state devices. Based on this strategy, devices with an enhanced stability and reduced hysteresis have been achieved. However, a fundamental understanding of the role of organic cations in inhibiting anionic diffusion across the perovskite-ligand interface is missing. Here we demonstrate the first quantitative investigation of the anionic interdiffusion across atomically flat 2D vertical heterojunctions. Interestingly, the halide diffusion does not follow the classical diffusion process. Instead, a 'quantized' layer-by-layer diffusion model is proposed to describe the behaviour of the anionic migration in 2D halide perovskites. Our results provide important insights into the mechanism of anionic diffusion in 2D perovskites and provide a new materials platform with an enhanced stability for heterostructure integration.

13.
Angew Chem Int Ed Engl ; 60(15): 8337-8343, 2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33497510

RESUMEN

Metal halide perovskites are promising for applications in light-emitting diodes (LEDs), but still suffer from defects-mediated nonradiative losses, which represent a major efficiency-limiting factor in perovskite-based LEDs (PeLEDs). Reported here is a strategy to synthesize molecular passivators with different anchoring groups for defects passivation. The passivated perovskite thin films exhibit improved optoelectronic properties as well as reduced grain size and surface roughness, thus enable highly efficient PeLEDs with an external quantum efficiency of 15.6 % using an imidazolium terminated passivator. Further demonstrated is that the in situ formation of low-dimensional perovskite phase on the surface of three-dimensional perovskite nanograins is responsible for surface defects passivation, which leads to significantly enhanced device performance. Our results provide new fundamental insights into the role of organic molecular passivators in boosting the performance of PeLEDs.

15.
mBio ; 11(5)2020 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-32900803

RESUMEN

Staphylococcus aureus is a major cause of prosthetic joint infection (PJI), which is characterized by biofilm formation. S. aureus biofilm skews the host immune response toward an anti-inflammatory profile by the increased recruitment of myeloid-derived suppressor cells (MDSCs) that attenuate macrophage proinflammatory activity, leading to chronic infection. A screen of the Nebraska Transposon Mutant Library identified several hits in the ATP synthase operon that elicited a heightened inflammatory response in macrophages and MDSCs, including atpA, which encodes the alpha subunit of ATP synthase. An atpA transposon mutant (ΔatpA) had altered growth kinetics under both planktonic and biofilm conditions, along with a diffuse biofilm architecture that was permissive for leukocyte infiltration, as observed by confocal laser scanning microscopy. Coculture of MDSCs and macrophages with ΔatpA biofilm elicited significant increases in the proinflammatory cytokines interleukin 12p70 (IL-12p70), tumor necrosis factor alpha (TNF-α), and IL-6. This was attributed to increased leukocyte survival resulting from less toxin and protease production by ΔatpA biofilm as determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The enhanced inflammatory response elicited by ΔatpA biofilm was cell lysis-dependent since it was negated by polyanethole sodium sulfanate treatment or deletion of the major autolysin, Atl. In a mouse model of PJI, ΔatpA-infected mice had decreased MDSCs concomitant with increased monocyte/macrophage infiltrates and proinflammatory cytokine production, which resulted in biofilm clearance. These studies identify S. aureus ATP synthase as an important factor in influencing the immune response during biofilm-associated infection and bacterial persistence.IMPORTANCE Medical device-associated biofilm infections are a therapeutic challenge based on their antibiotic tolerance and ability to evade immune-mediated clearance. The virulence determinants responsible for bacterial biofilm to induce a maladaptive immune response remain largely unknown. This study identified a critical role for S. aureus ATP synthase in influencing the host immune response to biofilm infection. An S. aureus ATP synthase alpha subunit mutant (ΔatpA) elicited heightened proinflammatory cytokine production by leukocytes in vitro and in vivo, which coincided with improved biofilm clearance in a mouse model of prosthetic joint infection. The ability of S. aureus ΔatpA to augment host proinflammatory responses was cell lysis-dependent, as inhibition of bacterial lysis by polyanethole sodium sulfanate or a ΔatpAΔatl biofilm did not elicit heightened cytokine production. These studies reveal a critical role for AtpA in shaping the host immune response to S. aureus biofilm.


Asunto(s)
Complejos de ATP Sintetasa/genética , Complejos de ATP Sintetasa/inmunología , Biopelículas/crecimiento & desarrollo , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata , Staphylococcus aureus/enzimología , Staphylococcus aureus/inmunología , Complejos de ATP Sintetasa/metabolismo , Animales , Citocinas/inmunología , Modelos Animales de Enfermedad , Macrófagos/inmunología , Macrófagos/microbiología , Ratones , Ratones Endogámicos C57BL , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad
16.
Oncotarget ; 11(28): 2747-2762, 2020 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-32733646

RESUMEN

The TMEM165 gene encodes for a multiple pass membrane protein localized in the Golgi that has been linked to congenital disorders of glycosylation. The TMEM165 protein is a putative ion transporter that regulates H+/Ca++/Mn++ homeostasis and pH in the Golgi. Previously, we identified TMEM165 as a potential biomarker for breast carcinoma in a glycoproteomic study using late stage invasive ductal carcinoma tissues with patient- matched adjacent normal tissues. The TMEM165 protein was not detected in non-malignant matched breast tissues and was detected in invasive ductal breast carcinoma tissues by mass spectrometry. Our hypothesis is that the TMEM165 protein confers a growth advantage to breast cancer. In this preliminary study we have investigated the expression of TMEM165 in earlier stage invasive ductal carcinoma and ductal carcinoma in situ cases. We created a CRISPR/Cas9 knockout of TMEM165 in the human invasive breast cancer cell line MDAMB231. Our results indicate that removal of TMEM165 in these cells results in a significant reduction of cell migration, tumor growth, and tumor vascularization in vivo. Furthermore, we find that TMEM165 expression alters the glycosylation of breast cancer cells and these changes promote the invasion and growth of breast cancer by altering the expression levels of key glycoproteins involved in regulation of the epithelial to mesenchymal transition such as E-cadherin. These studies illustrate new potential functions for this Golgi membrane protein in the control of breast cancer growth and invasion.

18.
Am J Infect Control ; 48(8): 955-957, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32505792
19.
BJS Open ; 4(4): 593-600, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32374504

RESUMEN

BACKGROUND: Propensity score (PS) regression analysis can be used to minimize differences between cohorts in order to perform comparisons The aim of this study was to use PS analysis to examine the outcomes of oesophageal adenocarcinoma (OAC) treatment with surgery alone or neoadjuvant chemotherapy (NAC) followed by surgery (NACS), to see whether the benefits seen in a randomized trial (MRC OE02) were reproducible in a UK cancer network clinical practice. METHODS: Consecutive patients undergoing potentially curative treatment for OAC in a regional cancer network were studied. Multiple regression models, including PS analysis, were developed to account for confounding factors. Primary outcome measures were disease-free (DFS) and overall (OS) survival. RESULTS: A cohort of 440 patients was included in a regression analysis controlling for confounders (176 surgery alone, 264 NACS). NACS was associated with a higher positive margin status rate compared with surgery alone (42·4 versus 26·7 per cent respectively; P < 0·001), an inferior 5-year DFS rate (32·1 versus 56·9 per cent; P < 0·001) and a worse 5-year OS rate (27·5 versus 47·3 per cent; P < 0·001). On regression adjustment based on propensity scores, NACS was not associated with DFS (P = 0·220) or OS (P = 0·431). The Mandard tumour regression grade (TRG) score was significantly associated with DFS (hazard ratio (HR) 0·21, 95 per cent c.i. 0·07 to 0·70) and OS (HR 0·27, 0·13 to 0·59). Five-year DFS and OS rates related to TRG were 64 and 62 per cent respectively for 25 good responders versus 8·0 and 8·6 per cent for 127 poor responders (P < 0·001). CONCLUSION: The prescription of NAC to all patients with OAC risks delay in effective treatment of patients who are relatively chemoresistant, given the variability in pathological response. Identification of patients with OAC who may derive the most benefit from NAC should be the focus.


ANTECEDENTES: El análisis de regresión por puntaje de propensión (propensity score, PS) puede ser utilizado para minimizar las diferencias entre cohortes a la hora de hacer comparaciones. El objetivo de este estudio fue utilizar el PS para analizar los resultados del tratamiento del adenocarcinoma de esófago (oesophageal adenocarcinoma, OAC), tanto con cirugia sola (surgery, S) o con quimioterapia neoadyuvante (neoadjuvant chemotherapy, NAC) seguida de cirugía (NACS) para determinar si los beneficios del ensayo aleatorizado MRC OE02 eran reproducibles en la práctica clínica de una red de cáncer del Reino Unido. MÉTODOS: Se estudiaron pacientes consecutivos sometidos a tratamiento potencialmente curativo por OAC en una red de cáncer regional. Se desarrollaron modelos de regresión múltiple, incluyendo PS, para poder ajustar por factores de confusión. Las medidas de resultado primario fueron supervivencia libre de enfermedad (disease-free survival, DFS) y la supervivencia global (overall survival, OS). RESULTADOS: Se incluyó una cohorte de 440 pacientes en un análisis de regresión controlando por factores de confusión (176 S, 264 NACS). NACS se asoció con margen positivo (NACS versus S, 42,4% versus 26,7%, P < 0,001), menor DFS a los 5 años (32,1% versus 56,9, P < 0,001) y peor OS a los 5 años (27,5% versus 47,3%, P < 0,001). En el ajuste de la regresión basada en las puntuaciones de propensión, NACS no se asoció a DFS (P = 0,220) ni a OS (P = 0,431). El grado de regresión tumoral de Mandard (tumour regression grade, TRG) se asoció significativamente con DFS (cociente de riesgos instantáneos, hazard ratio, HR 0,21, i.c. del 95% 0,13-0,59). La DFS y OS a los 5 años en relación con TRG fue 63,6% y 61,5% versus 8,0% y 8,6% (P < 0,001) para buenos y pobres respondedores, respectivamente. CONCLUSIÓN: La indicación de NAC a todos los pacientes con OAC representa un riesgo de demorar un tratamiento efectivo para aquellos pacientes que son relativamente quimiorresistentes, dada la variabilidad en la respuesta patológica. Identificar a los pacientes con OAC que obtendrían el mayor beneficio de la NAC debería centrar el foco de atención.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/mortalidad , Adenocarcinoma/cirugía , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/mortalidad , Neoplasias Esofágicas/cirugía , Anciano , Quimioterapia Adyuvante , Estudios de Cohortes , Terapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Clasificación del Tumor , Puntaje de Propensión , Análisis de Regresión , Análisis de Supervivencia , Resultado del Tratamiento , Reino Unido/epidemiología
20.
Dermatol Surg ; 46(4): 537-545, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31464705

RESUMEN

BACKGROUND: Lentigo maligna (LM) is associated with disproportionately high surgical morbidity. OBJECTIVE: The authors report on 2 strategies to reduce the surgical morbidity associated with LM. METHODS: Forty LM lesions were removed with excisional biopsies without margins and closed with purse-string sutures. Invasive cases underwent staged excisions with 10-mm margins. Cases without invasion were treated with neoadjuvant topical imiquimod 5% cream (5 d/wk × 8 weeks) followed by conservative staged excisions with 2-mm margins using radial sections stained with hematoxylin and eosin and immunostaining with Mart-1, with or without SOX10. RESULTS: Invasion was detected in 12/40 (30%) of the excisional biopsy specimens (average depth 0.45 mm). No invasion was detected in 28/40 (70%). All 24 patients who completed neoadjuvant topical imiquimod 5% cream before staged excisions had negative first-stage margins at 2 mm. Compared with average published margins for LM, this represents a 71.4% reduction in the required margin and an average reduction in the final surgical defect by 74%. CONCLUSION: LM treatment by excisional biopsies with a purse-string closure enables accurate tumor staging and contracts the tumor footprint to its minimal size. Subsequent neoadjuvant imiquimod followed by a conservative staged excision with 2-mm margins allows for removal of LM with decreased surgical morbidity.


Asunto(s)
Peca Melanótica de Hutchinson/terapia , Imiquimod/administración & dosificación , Neoplasias Cutáneas/terapia , Herida Quirúrgica/terapia , Técnicas de Sutura , Administración Cutánea , Adulto , Anciano , Anciano de 80 o más Años , Biopsia/efectos adversos , Biopsia/métodos , Quimioterapia Adyuvante/métodos , Femenino , Humanos , Masculino , Márgenes de Escisión , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Herida Quirúrgica/etiología , Resultado del Tratamiento
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