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1.
Respir Med ; 224: 107564, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38360190

RESUMEN

BACKGROUND: Impulse oscillometry (IOS) is an effective tool for assessing airway mechanics and diagnosing obstructive airway disease (OAD) in children with sickle cell disease (C-SCD). Obesity is known to be associated with OAD, and untreated OAD often leads to hypoxia-related complications in C-SCD. Considering the increasing prevalence of obesity in C-SCD, it is important to explore the influence of body mass index (BMI) on OAD in this disease population. METHODS: A longitudinal retrospective chart review was conducted on 55 C-SCD (161 IOS observations) and 35 non-SCD asthmatic children (C-Asthma) (58 observations), primarily to investigate the association between BMI and airway resistance in C-SCD and C-Asthma. We conducted generalized linear mixed models (GLMM), adjusted for pharmacotherapies, to demonstrate the influence of BMI on total (R5), central (R20), and peripheral (R5-20) airway resistance and reactance (X5, resonant frequency (Fres)). We further compared age, BMI, and IOS indices between C-SCD and C-Asthma using the Mann-Whitney test. RESULTS: Age and BMI were not statistically different between the two groups. In C-SCD, BMI was associated with R5 (GLMM t-statistics:3.75, 95%CI:1.01,3.27, p-value<0.001*) and R20 (t-statistics:4.01, 95%CI:1.04,1.15, p-value<0.001*), but not with R5-20 or airway reactance. In asthmatics, BMI was not associated with IOS estimates except Fres (t-statistics: 3.93, 95%CI: -0.06, -0.02, p-value<0.001*). C-SCD demonstrated higher airway resistances (R5 and R20) and reactance (Fres) compared to C-Asthma (Mann-Whitney: p-values<0.05). CONCLUSION: BMI significantly influenced total and central airway resistance in C-SCD. While higher airway resistances reflected increased OAD in C-SCD than asthmatics, higher Fres perhaps indicated progressive pulmonary involvement in C-SCD.


Asunto(s)
Anemia de Células Falciformes , Asma , Niño , Humanos , Resistencia de las Vías Respiratorias , Índice de Masa Corporal , Estudios Retrospectivos , Estudios Longitudinales , Oscilometría , Espirometría , Pulmón , Asma/tratamiento farmacológico , Anemia de Células Falciformes/complicaciones , Obesidad
2.
Tissue Eng Part A ; 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-37930720

RESUMEN

Developing a reproducible and secure supply of customizable control tissues that standardizes for the cell type, tissue architecture, and preanalytics of interest for usage in applications including diagnostic, prognostic, and predictive assays, is critical for improving our patient care and welfare. The conventionally adopted control tissues directly obtained from patients are not ideal because they oftentimes have different amounts of normal and neoplastic elements, differing cellularity, differing architecture, and unknown preanalytics, in addition to the limited supply availability and thus associated high costs. In this study, we demonstrated a strategy to stably produce tissue-mimics for diagnostics purposes by taking advantage of the three-dimensional (3D) bioprinting technology. Specifically, we take anaplastic lymphoma kinase-positive (Alk+) lung cancer as an example, where a micropore-forming bioink laden with tumor cells was combined with digital light processing-based bioprinting for developing native-like Alk+ lung cancer tissue-mimics with both structural and functional relevancy. It is anticipated that our proposed methodology will pave new avenues for both fields of tissue diagnostics and 3D bioprinting significantly expanding their capacities, scope, and sustainability.

3.
ACS Nano ; 17(13): 12140-12150, 2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37368885

RESUMEN

Over the past few years, graphene grown by chemical vapor deposition (CVD) has gained prominence as a template to grow transition metal dichalcogenide (TMD) overlayers. The resulting two-dimensional (2D) TMD/graphene vertical heterostructures are attractive for optoelectronic and energy applications. However, the effects of the microstructural heterogeneities of graphene grown by CVD on the growth of the TMD overlayers are relatively unknown. Here, we present a detailed investigation of how the stacking order and twist angle of CVD graphene influence the nucleation of WSe2 triangular crystals. Through the combination of experiments and theory, we correlate the presence of interlayer dislocations in bilayer graphene with how WSe2 nucleates, in agreement with the observation of a higher nucleation density of WSe2 on top of Bernal-stacked bilayer graphene versus twisted bilayer graphene. Scanning/transmission electron microscopy (S/TEM) data show that interlayer dislocations are present only in Bernal-stacked bilayer graphene but not in twisted bilayer graphene. Atomistic ReaxFF reactive force field molecular dynamics simulations reveal that strain relaxation promotes the formation of these interlayer dislocations with localized buckling in Bernal-stacked bilayer graphene, whereas the strain becomes distributed in twisted bilayer graphene. Furthermore, these localized buckles in graphene are predicted to serve as thermodynamically favorable sites for binding WSex molecules, leading to the higher nucleation density of WSe2 on Bernal-stacked graphene. Overall, this study explores synthesis-structure correlations in the WSe2/graphene vertical heterostructure system toward the site-selective synthesis of TMDs by controlling the structural attributes of the graphene substrate.

4.
Sens Actuators B Chem ; 3782023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36644326

RESUMEN

As an easily disposable substrate with a microporous texture, paper is a well-suited, generic substrate to build analytical devices for studying bacteria. Using a multi-pass lasing process, cellulose-based laser-induced graphene (cLIG) with a sheet resistance of 43.7 ± 2.3 Ωsq-1 is developed and utilized in the fabrication of low-cost and environmentally-friendly paper sensor arrays. Two case studies with Pseudomonas aeruginosa and Escherichia coli demonstrate the practicality of the cLIG sensors for the electrochemical analysis of bacteria. The first study measures the time-dependent profile of phenazines released from both planktonic (up to 60 h) and on-chip-grown (up to 22 h) Pseudomonas aeruginosa cultures. While similarities do exist, marked differences in phenazine production are seen with cells grown directly on cLIG compared to the planktonic culture. Moreover, in planktonic cultures, pyocyanin levels increase early on and plateau around 20 h, while optical density measurements increase monotonically over the duration of testing. The second study monitors the viability and metabolic activity of Escherichia coli using a resazurin-based electrochemical assay. These results demonstrate the utility of cLIG paper sensors as an inexpensive and versatile platform for monitoring bacteria and could enable new opportunities in high-throughput antibiotic susceptibility testing, ecological studies, and biofilm studies.

5.
Cell Rep ; 40(9): 111268, 2022 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-36044842

RESUMEN

Patients with human epidermal growth factor receptor 2-positive (HER2+/ERBB2) breast cancer often present with brain metastasis. HER2-targeted therapies have not been successful to treat brain metastases in part due to poor blood-brain barrier (BBB) penetrance and emergence of resistance. Here, we report that Abelson (ABL) kinase allosteric inhibitors improve overall survival and impair HER2+ brain metastatic outgrowth in vivo. Mechanistically, ABL kinases phosphorylate the RNA-binding protein Y-box-binding protein 1 (YB-1). ABL kinase inhibition disrupts binding of YB-1 to the ERBB2 mRNA and impairs translation, leading to a profound decrease in HER2 protein levels. ABL-dependent tyrosine phosphorylation of YB-1 promotes HER2 translation. Notably, loss of YB-1 inhibits brain metastatic outgrowth and impairs expression of a subset of ABL-dependent brain metastatic targets. These data support a role for ABL kinases in the translational regulation of brain metastatic targets through YB-1 and offer a therapeutic target for HER2+ brain metastasis patients.


Asunto(s)
Neoplasias Encefálicas , Neoplasias de la Mama , Proteínas Proto-Oncogénicas c-abl , Proteína 1 de Unión a la Caja Y , Encéfalo/metabolismo , Neoplasias Encefálicas/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/secundario , Línea Celular Tumoral , Femenino , Humanos , Proteínas Proto-Oncogénicas c-abl/metabolismo , Receptor ErbB-2/metabolismo , Proteína 1 de Unión a la Caja Y/genética
6.
Sci Rep ; 12(1): 14710, 2022 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-36038601

RESUMEN

Earth's mineral deposits show a non-uniform spatial distribution from the craton-scale, to the scale of individual mineral districts. Although this pattern of differential metal endowment is underpinned by lithospheric-scale processes the geological features that cause clustering of deposits remains enigmatic. The integration of geological and geophysical (seismic, gravity, and magnetotelluric) features has produced the first whole-of-crust image through an iconic Neoarchean volcanic complex and mineral district in the Abitibi Greenstone Belt, Superior Province, Canada. Observations indicate an asymmetry in surface geology, structure, and crustal architecture that defines deep transcrustal magmatic-hydrothermal upflow zones and the limits of the Noranda District ore system. Here, extreme volcanogenic massive sulfide (VMS) endowment is confined to a smaller area adjacent to an ancestral transcrustal structure interpreted to have localized and optimized magmatic and ore forming processes. Although lithospheric-scale evolutionary processes might act as the fundamental control on metal endowment, the new crustal reconstruction explains the clustering of deposits on both belt and district scales. The results highlight a strong magmatic control on metal and in particular Au endowment in VMS systems. Overprinting by clusters of ca. 30 Ma younger orogenic Au deposits suggest the ore systems accessed an upper lithospheric mantle enriched in Au and metals.

7.
Sci Adv ; 8(29): eabm7833, 2022 07 22.
Artículo en Inglés | MEDLINE | ID: mdl-35857833

RESUMEN

Subunit vaccines inducing antibodies against tumor-specific antigens have yet to be clinically successful. Here, we use a supramolecular α-helical peptide nanofiber approach to design epitope-specific vaccines raising simultaneous B cell, CD8+ T cell, and CD4+ T cell responses against combinations of selected epitopes and show that the concurrent induction of these responses generates strong antitumor effects in mice, with significant improvements over antibody or CD8+ T cell-based vaccines alone, in both prophylactic and therapeutic subcutaneous melanoma models. Nanofiber vaccine-induced antibodies mediated in vitro tumoricidal antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). The addition of immune checkpoint and phagocytosis checkpoint blockade antibodies further improved the therapeutic effect of the nanofiber vaccines against murine melanoma. These findings highlight the potential clinical benefit of vaccine-induced antibody responses for tumor treatments, provided that they are accompanied by simultaneous CD8+ and CD4+ responses, and they illustrate a multiepitope cancer vaccine design approach using supramolecular nanomaterials.


Asunto(s)
Vacunas contra el Cáncer , Melanoma , Nanofibras , Animales , Epítopos , Inmunidad Celular , Ratones , Péptidos
8.
Blood Adv ; 6(17): 4936-4948, 2022 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-35816633

RESUMEN

Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for acute lymphoblastic leukemia (ALL), yet large amounts of data describing alloHCT outcomes in Philadelphia (Ph)-like ALL are lacking. We retrospectively analyzed archived DNA samples from consecutive adults with B-cell Ph-negative ALL who underwent alloHCT in complete remission (CR) (n = 127) at our center between 2006 and 2020. Identification of fusions associated with Ph-like ALL was performed using cumulative results from RNA-seq, conventional cytogenetics, fluorescence in situ hybridization, and whole genome array studies. Fusions associated with Ph-like ALL were detected in 56 (44%) patients, of whom 38 were carrying CRLF2r. Compared with other non-Ph-like ALL (n = 71), patients with fusions associated with Ph-like ALL were more frequently Hispanic (P = .008), were less likely to carry high-risk cytogenetics (P < .001), and were more likely to receive blinatumomab prior to HCT (P = .019). With the median followup of 3.5 years, patients with Ph-like ALL fusions had comparable posttransplant outcomes compared with other B-cell ALL: 3-year relapse-free survival (RFS) (41% vs 44%; P = .36), overall survival (OS) (51% vs 50%; P = .59), and relapse (37% vs 31%; P = .47). In multivariable analysis, age (P = .023), disease status at the time of transplant (P < .001), and donor type (P = .015) influenced OS. RFS (primary endpoint) was significantly influenced by disease status (P < .001) and conditioning regimen intensity (P = .014). In conclusion, our data suggest that alloHCT consolidation results in similarly favorable survival outcomes in adult patients with Ph-like fusions and other high-risk B-cell ALL.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Enfermedad Aguda , Adulto , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Hibridación Fluorescente in Situ , Philadelphia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Recurrencia , Estudios Retrospectivos , Trasplante Homólogo
9.
Transplant Cell Ther ; 28(7): 367.e1-367.e9, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35534000

RESUMEN

Total body irradiation in combination with melphalan for multiple myeloma (MM) has been shown to be prohibitively toxic. To ameliorate toxicity, total marrow irradiation (TMI) has been administered as the sole ablative modality during the second cycle of tandem autologous stem cell transplantation (TASCT) for MM patients on a phase I-II trial. Patients with MM in response or with stable disease and ≤18 months from diagnosis received melphalan 200 mg/m2 and autologous stem cell transplantation (ASCT) (cycle 1) and then, after recovery, TMI and another ASCT (cycle 2), followed by maintenance with an immunomodulatory drug (ImiD) and dexamethasone for up to 12 months. TMI doses were escalated from 1000 cGy to 1800 cGy in 200-cGy increments. Fifty-four patients were to receive TASCT between 2004 and 2011; 8 patients received single ASCT because of patient or physician preference. The median time between melphalan and TMI was 65 days (range, 47 to 125 days). Thirty patients (55.6%) underwent TASCT at the maximum tolerated dose of 1600 cGy. The complete response and very good partial response rates were 48.1% and 22.2%, respectively, following ASCT and maintenance. The median follow-up among survivors was 12.3 years (range, 9.2 to 15.5+ years). Progression-free survival (PFS) and overall survival at 10 years were 20.4% (95% confidence interval [CI], 10.9% to 31.9%) and 38.8% (95% CI, 25.9% to 51.5%), respectively. Secondary neoplasms included (1 each) acute myelogenous leukemia, papillary thyroid and prostate carcinoma, and melanoma, and there was 1 case of ductal carcinoma in situ and 4 cases of nonmelanoma skin cancers. TMI as part of TASCT was well tolerated, and TASCT was associated with a 20.4% PFS plateau. The inclusion of TMI as a conditioning regiment for MM before ASCT warrants further study in the context of modern induction and maintenance therapies.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Mieloma Múltiple , Médula Ósea/efectos de la radiación , Estudios de Seguimiento , Humanos , Masculino , Melfalán/uso terapéutico , Mieloma Múltiple/terapia , Trasplante Autólogo
10.
Ann Surg Open ; 3(1): e141, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37600110

RESUMEN

Objective: We describe a structured approach to developing a standardized curriculum for surgical trainees in East, Central, and Southern Africa (ECSA). Summary Background Data: Surgical education is essential to closing the surgical access gap in ECSA. Given its importance for surgical education, the development of a standardized curriculum was deemed necessary. Methods: We utilized Kern's 6-step approach to curriculum development to design an online, modular, flipped-classroom surgical curriculum. Steps included global and targeted needs assessments, determination of goals and objectives, the establishment of educational strategies, implementation, and evaluation. Results: Global needs assessment identified the development of a standardized curriculum as an essential next step in the growth of surgical education programs in ECSA. Targeted needs assessment of stakeholders found medical knowledge challenges, regulatory requirements, language variance, content gaps, expense and availability of resources, faculty numbers, and content delivery method to be factors to inform curriculum design. Goals emerged to increase uniformity and consistency in training, create contextually relevant material, incorporate best educational practices, reduce faculty burden, and ease content delivery and updates. Educational strategies centered on developing an online, flipped-classroom, modular curriculum emphasizing textual simplicity, multimedia components, and incorporation of active learning strategies. The implementation process involved establishing thematic topics and subtopics, the content of which was authored by regional surgeon educators and edited by content experts. Evaluation was performed by recording participation, soliciting user feedback, and evaluating scores on a certification examination. Conclusions: We present the systematic design of a large-scale, context-relevant, data-driven surgical curriculum for the ECSA region.

11.
Blood Adv ; 6(5): 1444-1453, 2022 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-34581764

RESUMEN

We report results of our prospective pilot trial evaluating safety/feasibility of peritransplantation ruxolitinib for myelofibrosis treatment. Primary objectives were to determine safety and maximum tolerated dose (MTD) of ruxolitinib. Ruxolitinib was administered at 2 dose levels (DLs) of 5 and 10 mg twice daily, with fludarabine/melphalan conditioning regimen and tacrolimus/sirolimus graft-versus-host disease (GVHD) prophylaxis. We enrolled 6 and 12 patients at DL1 and DL2, respectively. Median age at transplantation was 65 years (range, 25-73). Per Dynamic International Prognostic Scoring System, 4 patients were high and 14 intermediate risk. Peripheral blood stem cells were graft source from matched sibling (n = 5) or unrelated (n = 13) donor. At each DL, 1 patient developed dose-limiting toxicities (DLTs): grade 3 cardiac and gastrointestinal with grade 4 pulmonary DLTs in DL1, and grade 3 kidney injury in DL2. All patients achieved engraftment. Grade 2 to 4 and 3 to 4 acute GVHD cumulative incidence was 17% (95% confidence interval [CI], 6-47) and 11% (95% CI, 3-41), respectively. Cumulative incidence of 1-year chronic GVHD was 42% (95% CI, 24-74). With 22.6-month (range, 6.2-25.8) median follow-up in surviving patients, 1-year overall and progression-free survival were 77% (95% CI, 50-91) and 71% (95% CI, 44-87), respectively. Causes of death (n = 4) were cardiac arrest, GVHD, respiratory failure, and refractory GVHD of liver. Our results show peritransplantation ruxolitinib is safe and well tolerated at MTD of 10 mg twice daily and associated with dose-dependent pharmacokinetic and cytokine profile. Early efficacy data are highly promising in high-risk older patients with myelofibrosis. This trial was registered at www.clinicaltrials.gov as #NCT02917096.


Asunto(s)
Enfermedad Injerto contra Huésped , Mielofibrosis Primaria , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Nitrilos , Estudios Prospectivos , Pirazoles , Pirimidinas/uso terapéutico
12.
Cancer Treat Res ; 181: 97-114, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34626357

RESUMEN

The discovery of the tyrosine kinase inhibitor (TKI) imatinib in the early 2000's revolutionized the treatment and prognosis of patients with chronic myeloid leukemia (CML) [Hochhaus et al. in N Engl J Med 376:917-927, 2017]. The treatment of patients with CML has changed dramatically since the approval of imatinib and other TKIs. Before the TKI era, newly diagnosed patients would undergo HLA typing to try to identify a well-matched donor, and then proceed quickly to allogeneic hematopoietic cell transplantation (HCT). With the introduction of imatinib followed a few years later by dasatinib, nilotinib, then bosutinib, treatment approaches changed in a dramatic way. Transplantation is no longer an upfront treatment option for newly diagnosed CML patients, and in fact, it is very rarely used in the management of a patient with CML currently. The management of CML patients has been a model of personalized medicine or targeted therapy that is being emulated in the treatment of many other hematologic malignancies and solid tumors such as lung cancer [Soverini et al. in Mol Cancer 17:49, 2018]. The Philadelphia Chromosome (Ph) which leads to the formation of the BCR-ABL fusion gene and its product the BCR-ABL protein is the cause of CML. With effective targeting of this protein with the available TKIs, the disease is completely controllable if not curable for most patients. Life expectancy for patients with CML is essentially normal. Quality of life becomes an important goal including the potential for pregnancy, and ultimately the chance to discontinue all TKI therapy permanently. The three cases outlined below serve to highlight some of the important issues in the management of patients with CML in the post-TKI era.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva , Calidad de Vida , Resistencia a Antineoplásicos , Proteínas de Fusión bcr-abl/genética , Humanos , Mesilato de Imatinib , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico
13.
Cancer Treat Res ; 181: 151-165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34626360

RESUMEN

The classical myeloproliferative neoplasms (MPN) are characterized by clonal expansion of one or more hematopoietic cell lineages and are driven by mutations that activate constitutive signaling via JAK2 pathway. The criteria for diagnosis have now been defined by the World Health Organization (WHO) and the term MPN as is currently used encompasses the entities of primary myelofibrosis, polycythemia vera, and essential thrombocytosis. There is imperfect correlation between the genotype and disease phenotype in MPN and the latter is determined by a variety of patient factors that are independent of the driver mutation. The disease course in MPN can span decades and accurate risk assessment is critical in the choice of therapy and treatment is largely geared toward prevention of complications and providing symptomatic relief. Although new agents have been approved in recent years, no therapy has been convincingly shown to alter disease progression and allogeneic hematopoietic stem cell transplantation (HCT) remains the only curative therapy known to date.


Asunto(s)
Trastornos Mieloproliferativos , Policitemia Vera , Mielofibrosis Primaria , Trombocitemia Esencial , Biología , Humanos , Mutación , Trastornos Mieloproliferativos/genética , Trastornos Mieloproliferativos/terapia , Mielofibrosis Primaria/diagnóstico , Mielofibrosis Primaria/genética , Mielofibrosis Primaria/terapia
14.
ACS Appl Mater Interfaces ; 13(34): 40817-40829, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34470105

RESUMEN

ß-phase gallium oxide (Ga2O3) is an emerging ultrawide bandgap (UWBG) semiconductor (EG ∼ 4.8 eV), which promises generational improvements in the performance and manufacturing cost over today's commercial wide bandgap power electronics based on GaN and SiC. However, overheating has been identified as a major bottleneck to the performance and commercialization of Ga2O3 device technologies. In this work, a novel Ga2O3/4H-SiC composite wafer with high heat transfer performance and an epi-ready surface finish has been developed using a fusion-bonding method. By taking advantage of low-temperature metalorganic vapor phase epitaxy, a Ga2O3 epitaxial layer was successfully grown on the composite wafer while maintaining the structural integrity of the composite wafer without causing interface damage. An atomically smooth homoepitaxial film with a room-temperature Hall mobility of ∼94 cm2/Vs and a volume charge of ∼3 × 1017 cm-3 was achieved at a growth temperature of 600 °C. Phonon transport across the Ga2O3/4H-SiC interface has been studied using frequency-domain thermoreflectance and a differential steady-state thermoreflectance approach. Scanning transmission electron microscopy analysis suggests that phonon transport across the Ga2O3/4H-SiC interface is dominated by the thickness of the SiNx bonding layer and an unintentionally formed SiOx interlayer. Extrinsic effects that impact the thermal conductivity of the 6.5 µm thick Ga2O3 layer were studied via time-domain thermoreflectance. Thermal simulation was performed to estimate the improvement of the thermal performance of a hypothetical single-finger Ga2O3 metal-semiconductor field-effect transistor fabricated on the composite substrate. This novel power transistor topology resulted in a ∼4.3× reduction in the junction-to-package device thermal resistance. Furthermore, an even more pronounced cooling effect is demonstrated when the composite wafer is implemented into the device design of practical multifinger devices. These innovations in device-level thermal management give promise to the full exploitation of the promising benefits of the UWBG material, which will lead to significant improvements in the power density and efficiency of power electronics over current state-of-the-art commercial devices.

15.
ACS Appl Mater Interfaces ; 13(32): 38477-38490, 2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-34370459

RESUMEN

Heteroepitaxy of ß-phase gallium oxide (ß-Ga2O3) thin films on foreign substrates shows promise for the development of next-generation deep ultraviolet solar blind photodetectors and power electronic devices. In this work, the influences of the film thickness and crystallinity on the thermal conductivity of (2̅01)-oriented ß-Ga2O3 heteroepitaxial thin films were investigated. Unintentionally doped ß-Ga2O3 thin films were grown on c-plane sapphire substrates with off-axis angles of 0° and 6° toward ⟨112̅0⟩ via metal-organic vapor phase epitaxy (MOVPE) and low-pressure chemical vapor deposition. The surface morphology and crystal quality of the ß-Ga2O3 thin films were characterized using scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. The thermal conductivities of the ß-Ga2O3 films were measured via time-domain thermoreflectance. The interface quality was studied using scanning transmission electron microscopy. The measured thermal conductivities of the submicron-thick ß-Ga2O3 thin films were relatively low as compared to the intrinsic bulk value. The measured thin film thermal conductivities were compared with the Debye-Callaway model incorporating phononic parameters derived from first-principles calculations. The comparison suggests that the reduction in the thin film thermal conductivity can be partially attributed to the enhanced phonon-boundary scattering when the film thickness decreases. They were found to be a strong function of not only the layer thickness but also the film quality, resulting from growth on substrates with different offcut angles. Growth of ß-Ga2O3 films on 6° offcut sapphire substrates was found to result in higher crystallinity and thermal conductivity than films grown on on-axis c-plane sapphire. However, the ß-Ga2O3 films grown on 6° offcut sapphire exhibit a lower thermal boundary conductance at the ß-Ga2O3/sapphire heterointerface. In addition, the thermal conductivity of MOVPE-grown (2̅01)-oriented ß-(AlxGa1-x)2O3 thin films with Al compositions ranging from 2% to 43% was characterized. Because of phonon-alloy disorder scattering, the ß-(AlxGa1-x)2O3 films exhibit lower thermal conductivities (2.8-4.7 W/m·K) than the ß-Ga2O3 thin films. The dominance of the alloy disorder scattering in ß-(AlxGa1-x)2O3 is further evidenced by the weak temperature dependence of the thermal conductivity. This work provides fundamental insight into the physical interactions that govern phonon transport within heteroepitaxially grown ß-phase Ga2O3 and (AlxGa1-x)2O3 thin films and lays the groundwork for the thermal modeling and design of ß-Ga2O3 electronic and optoelectronic devices.

16.
ACS Omega ; 6(31): 20598-20610, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34396005

RESUMEN

Graphene shows great promise not only as a highly conductive flexible and transparent electrode for fabricating novel device architectures but also as an ideal synthesis platform for studying fundamental growth mechanisms of various materials. In particular, directly depositing metal phthalocyanines (MPc's) on graphene is viewed as a compelling approach to improve the performance of organic photovoltaics and light-emitting diodes. In this work, we systematically investigate the ZnPc physical vapor deposition (PVD) on graphene either as-grown on Cu or as-transferred on various substrates including Si(100), C-plane sapphire, SiO2/Si, and h-BN. To better understand the effect of the substrate on the ZnPc structure and morphology, we also compare the ZnPc growth on highly crystalline single- and multilayer graphene. The experiments show that, for identical deposition conditions, ZnPc exhibits various morphologies such as high-aspect-ratio nanowires or a continuous film when changing the substrate supporting graphene. ZnPc morphology is also found to transition from a thin film to a nanowire structure when increasing the number of graphene layers. Our observations suggest that substrate-induced changes in graphene affect the adsorption, surface diffusion, and arrangement of ZnPc molecules. This study provides clear guidelines to control MPc crystallinity, morphology, and molecular orientations which drastically influence the (opto)electronic properties.

18.
Blood Adv ; 5(12): 2650-2659, 2021 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-34156440

RESUMEN

Efficacy of PTCy after mismatched unrelated donor (MMUD) HCT is unknown. In this pilot clinical trial, we enrolled 38 patients with hematologic malignancies scheduled to undergo MMUD-HCT (≥6/8 HLA-matched donors) onto 1 of 2 conditioning strata: myeloablative using fludarabine and fractionated total body irradiation (n = 19) or reduced intensity with fludarabine/melphalan (n = 19). Graft source was peripheral blood stem cells (PBSCs), and GVHD prophylaxis was PTCy, tacrolimus, and mycophenolate mofetil. Patients' median age was 53 years (range, 21-72 years). Median number of HLA mismatches was 2 (range, 1-4) of 12 loci. Twenty-three patients (61%) were considered racial (n = 12) or ethnic (n = 11) minorities. Median time to neutrophil engraftment was 16 days (range, 13-35 days). With a median follow-up of 18.3 months (range, 4.3-25.0 months) for surviving patients, 1-year overall survival (OS) and GVHD-free/relapse-free survival (GRFS) were 87% (95% confidence interval [CI]: 71-94) and 68% (95% CI: 51-81), respectively. Cumulative incidence of nonrelapse mortality at 100 days and 1 year were 0% and 11% (95% CI: 4-27), respectively, whereas relapse/progression was 11% (95% CI: 4-27). Cumulative incidence of 100-day acute GVHD grades 2-4 and 3-4 and 1-year chronic GVHD were 50% (95% CI: 36-69), 18% (95% CI: 9-36), and 48% (95% CI: 34-68), respectively. The rate of moderate/severe chronic GVHD was 3% in the entire cohort. We showed highly promising OS/GRFS rates with an acceptable risk profile after PBSC-MMUD-HCT with PTCy. This trial was registered at www.clinicaltrials.gov as #NCT03128359.


Asunto(s)
Enfermedad Injerto contra Huésped , Células Madre de Sangre Periférica , Ciclofosfamida/uso terapéutico , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Donante no Emparentado
19.
Int J Pediatr Otorhinolaryngol ; 146: 110733, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33940315

RESUMEN

OBJECTIVE: To compare the effect of surgical specialty and patient factors on 30-day postoperative outcomes and complications for children undergoing autologous costochondral grafting for microtia reconstruction. METHODS: The American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) database was searched from 2012 through 2017 for patients who underwent autologous rib grafting (CPT 21230). The group was further filtered for coexisting ICD 9 or 10 code for microtia (744.23, Q17.2) as an indication for surgery. Outcomes analyzed included patient demographics, medical comorbidities, admission type (inpatient vs. outpatient), operative time, surgeon specialty, length of hospital stay (LOS), complications, and readmission. RESULTS: A total of 375 pediatric patients were identified of which 157 were female and 218 were male. Mean age at time of surgery was 9.6 years. Postoperative complications and readmission occurred in 5.6% and 3.5% of patients, respectively. Surgical site infection was the most common complication. Average operative time was 246.9 min. When comparing Otolaryngology to Plastic Surgery with multivariate analysis, there was no difference in admission type (OR 1.00, p = 0.993), complication rate (OR 0.91, p = 0.744), readmission (OR 0.68, p = 0.576), operative time (p = 0.471) or total LOS (p = 0.266). CONCLUSION: The present study demonstrated postoperative complications and readmission rates following microtia repair as reported by the NSQIP-P database. Overall complication and readmission rates were low. No significant risk factors were identified on multivariate analysis. There were no differences between surgical specialty for complication rate, operative time, hospital stay or readmission when accounting for demographic data and comorbidities.


Asunto(s)
Microtia Congénita , Niño , Microtia Congénita/cirugía , Femenino , Humanos , Tiempo de Internación , Masculino , Readmisión del Paciente , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Costillas , Factores de Riesgo
20.
Molecules ; 26(5)2021 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-33803249

RESUMEN

Proteins are molecular machines requiring flexibility to function. Crystallographic B-factors and Molecular Dynamics (MD) simulations both provide insights into protein flexibility on an atomic scale. Nuclear Magnetic Resonance (NMR) lacks a universally accepted analog of the B-factor. However, a lack of convergence in atomic coordinates in an NMR-based structure calculation also suggests atomic mobility. This paper describes a pattern in the coordinate uncertainties of backbone heavy atoms in NMR-derived structural "ensembles" first noted in the development of FindCore2 (previously called Expanded FindCore: DA Snyder, J Grullon, YJ Huang, R Tejero, GT Montelione, Proteins: Structure, Function, and Bioinformatics 82 (S2), 219-230) and demonstrates that this pattern exists in coordinate variances across MD trajectories but not in crystallographic B-factors. This either suggests that MD trajectories and NMR "ensembles" capture motional behavior of peptide bond units not captured by B-factors or indicates a deficiency common to force fields used in both NMR and MD calculations.


Asunto(s)
Elasticidad/fisiología , Resistencia Flexional/fisiología , Proteínas/química , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/química , Biología Computacional/métodos , Cristalografía/métodos , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Simulación de Dinámica Molecular , Resonancia Magnética Nuclear Biomolecular/métodos , Conformación Proteica
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