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1.
Phys Chem Chem Phys ; 26(21): 15547-15558, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38756091

RESUMO

Polycyclic aromatic nitrogen heterocycles (PANHs) are present in various astronomical environments where they are subjected to intense radiation. Their photodissociation pathways give crucial insights into the cycle of matter in the universe, yet so far only the dissociation characteristics of few PANHs have been investigated. Moreover, most experiments use single photon techniques that only reveal the initial dissociation step, and are thus unsuited to replicate astronomical environments and timescales. In this work, we use the Instrument for the Photodynamics of PAHs (i-PoP) at the Laboratory for Astrophysics to simulate the interstellar photodissociation of a model PANH, cationic triazacoronene (TAC˙+, C21H9N3). Comparing the observed fragments to similar PAHs such as the isoelectronic coronene can give mechanistic insight into PAH dissociation. For coronene the major photodissociation products were found to be C9H+, C10+, and C11+. In contrast, fragmentation in TAC˙+ is initiated by up to three HCN losses often in combination with H- or H2 losses. In the lower mass region, the fragments show similarities to comparable PAHs like coronene, but for TAC˙+ the inclusion of nitrogen atoms into the ionic fragments in the form of e.g. (di)cyanopolyynes is also observed. These nitrogen-containing species may be important tracers of regions in interstellar space where interstellar PANHs are being photodissociated.

2.
Nat Commun ; 15(1): 2139, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459016

RESUMO

The pressing demand for sustainable energy storage solutions has spurred the burgeoning development of aqueous zinc batteries. However, kinetics-sluggish Zn2+ as the dominant charge carriers in cathodes leads to suboptimal charge-storage capacity and durability of aqueous zinc batteries. Here, we discover that an ultrathin two-dimensional polyimine membrane, featured by dual ion-transport nanochannels and rich proton-conduction groups, facilitates rapid and selective proton passing. Subsequently, a distinctive electrochemistry transition shifting from sluggish Zn2+-dominated to fast-kinetics H+-dominated Faradic reactions is achieved for high-mass-loading cathodes by using the polyimine membrane as an interfacial coating. Notably, the NaV3O8·1.5H2O cathode (10 mg cm-2) with this interfacial coating exhibits an ultrahigh areal capacity of 4.5 mAh cm-2 and a state-of-the-art energy density of 33.8 Wh m-2, along with apparently enhanced cycling stability. Additionally, we showcase the applicability of the interfacial proton-selective coating to different cathodes and aqueous electrolytes, validating its universality for developing reliable aqueous batteries.

3.
J Phys Chem C Nanomater Interfaces ; 128(8): 3514-3524, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38445014

RESUMO

A fundamental understanding of proton transport through graphene nanopores, defects, and vacancies is essential for advancing two-dimensional proton exchange membranes (PEMs). This study employs ReaxFF molecular dynamics, metadynamics, and density functional theory to investigate the enhanced proton transport through a graphene nanopore. Covalently functionalizing the nanopore with a benzenesulfonic group yields consistent improvements in proton permeability, with a lower activation barrier (≈0.15 eV) and increased proton selectivity over sodium cations. The benzenesulfonic functionality acts as a dynamic proton shuttle, establishing a favorable hydrogen-bonding network and an efficient proton transport channel. The model reveals an optimal balance between proton permeability and selectivity, which is essential for effective proton exchange membranes. Notably, the benzenesulfonic-functionalized graphene nanopore system achieves a theoretically estimated proton diffusion coefficient comparable to or higher than the current state-of-the-art PEM, Nafion. Ergo, the benzenesulfonic functionalization of graphene nanopores, firmly holds promise for future graphene-based membrane development in energy conversion devices.

4.
J Surg Oncol ; 129(5): 995-999, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38221660

RESUMO

BACKGROUND AND OBJECTIVES: With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates? METHODS: We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55 had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed. RESULTS: Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series. CONCLUSIONS: Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.


Assuntos
Fêmur , Falha de Prótese , Humanos , Pessoa de Meia-Idade , Desenho de Prótese , Estudos Retrospectivos , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Tíbia/diagnóstico por imagem , Tíbia/cirurgia , Reoperação , Resultado do Tratamento
5.
Biomacromolecules ; 25(2): 1027-1037, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38166400

RESUMO

Subunit vaccines would benefit from a safe particle-based adjuvant. Elastin-like polypeptide (ELP)-based micelles are interesting candidate adjuvants due to their well-defined size and easy modification with protein-based cargo. Coiled coils can facilitate noncovalent modifications, while potentially enhancing antigen delivery through interaction with cell membranes. ELP micelles comprise ELP diblock copolymers that self-assemble above a critical micelle temperature. In this study, an amphiphilic ELP was conjugated to peptide "K", which forms a heterodimeric coiled-coil complex with peptide "E". Self-assembled "covalent" micelles containing ELP-OVA323 (i.e., model antigen OVA323 conjugated to ELP), "coiled-coil" micelles containing ELP-K/E-OVA323 and "hybrid" micelles containing ELP-K and ELP-OVA323 were shown to be monodisperse and spherical. Dendritic cells (DCs) were exposed to all micelle compositions, and T-cell proliferation was investigated. The presence of ELP-K enhanced micelle uptake and subsequent DC maturation, resulting in enhanced CD4+ T-cell proliferation, which makes ELPs with coiled coil-associated antigens a promising vaccine platform.


Assuntos
Polipeptídeos Semelhantes à Elastina , Micelas , Elastina/química , Peptídeos/química , Antígenos , Ativação Linfocitária
6.
Asian Spine J ; 17(4): 666-675, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37226381

RESUMO

STUDY DESIGN: Retrospective cohort study. PURPOSE: To compare radiographic outcomes between unilateral and bilateral cage placement in transforaminal lumbar interbody fusions (TLIF) and to determine if the rate of fusion at the 1-year postoperative point was different in patients who received bilateral versus unilateral cages. OVERVIEW OF LITERATURE: There is no clear evidence to dictate whether bilateral or unilateral cages promote superior radiographic or surgical outcomes in TLIF. METHODS: Patients >18 years old who underwent primary one- or two-level TLIFs at our institution were identified and propensitymatched in a 3:1 fashion (unilateral:bilateral). Patient demographics, surgical characteristics, and radiographic outcomes, including vertebral endplate obliquity, segmental lordosis, subsidence, and fusion status, were compared between groups. RESULTS: Of the 184 patients included, 46 received bilateral cages. Bilateral cage placement was associated with greater subsidence (1.06±1.25 mm vs. 0.59±1.16 mm, p=0.028) and enhanced restoration of segmental lordosis (5.74°±14.1° vs. -1.57°±10.9°, p=0.002) at the 1-year postoperative point, while unilateral cage placement was associated with an increased correction of endplate obliquity (-2.02°±4.42° vs. 0.24°±2.81°, p<0.001). Bilateral cage placement was significantly associated with radiographic fusion on bivariate analysis (89.1% vs. 70.3%, p=0.018) and significantly predicted radiographic fusion on multivariable regression analysis (estimate, 1.35; odds ratio, 3.87; 95% confidence interval, 1.51-12.05; p=0.010). CONCLUSIONS: Bilateral interbody cage placement in TLIF procedures was associated with restoration of lumbar lordosis and increased fusion rates. However, endplate obliquity correction was significantly greater for patients who received a unilateral cage.

7.
JACS Au ; 3(2): 526-535, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36873699

RESUMO

The Angstrom-scale space between graphene and its substrate provides an attractive playground for scientific exploration and can lead to breakthrough applications. Here, we report the energetics and kinetics of hydrogen electrosorption on a graphene-covered Pt(111) electrode using electrochemical experiments, in situ spectroscopy, and density functional theory calculations. The graphene overlayer influences the hydrogen adsorption on Pt(111) by shielding the ions from the interface and weakening the Pt-H bond energy. Analysis of the proton permeation resistance with controlled graphene defect density proves that the domain boundary defects and point defects are the pathways for proton permeation in the graphene layer, in agreement with density functional theory (DFT) calculations of the lowest energy proton permeation pathways. Although graphene blocks the interaction of anions with the Pt(111) surfaces, anions do adsorb near the defects: the rate constant for hydrogen permeation is sensitively dependent on anion identity and concentration.

8.
Photochem Photobiol ; 99(2): 777-786, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36315051

RESUMO

Photosubstitutionally active ruthenium complexes show high potential as prodrugs for the photoactivated chemotherapy (PACT) treatment of tumors. One of the problems in PACT is that the localization of the ruthenium compound is hard to trace. Here, a ruthenium PACT prodrug, [Ru(3)(biq)(STF-31)](PF6 )2 (where 3 = 3-(([2,2':6',2″-ter- pyridin]-4'-yloxy)propyl-4-(pyren-1-yl)butanoate) and biq = 2,2'-biquinoline), has been prepared, in which a pyrene tracker is attached via an ester bond. The proximity between the fluorophore and the ruthenium center leads to fluorescence quenching. Upon intracellular hydrolysis of the ester linkage, however, the fluorescence of the pyrene moiety is recovered, thus demonstrating prodrug cellular uptake. Further light irradiation of this molecule liberates by photosubstitution STF-31, a known cytotoxic nicotinamide phosphoribosyltransferase (NAMPT) inhibitor, as well as singlet oxygen via excitation of the free pyrene chromophore. The dark and light cytotoxicity of the prodrug, embedded in liposomes, as well as the appearance of blue emission upon uptake, were evaluated in A375 human skin melanoma cells. The cytotoxicity of the liposome-embedded prodrug was indeed increased by light irradiation. This work realizes an in vitro proof-of-concept of the lock-and-kill principle, which may ultimately be used to design strategies aimed at knowing where and when light irradiation should be realized in vivo.


Assuntos
Antineoplásicos , Complexos de Coordenação , Neoplasias , Pró-Fármacos , Rutênio , Humanos , Complexos de Coordenação/química , Rutênio/química , Pró-Fármacos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-38274277

RESUMO

Background: Arthroscopic lysis of adhesions is a treatment option for patients with painful, stiff knees as a result of arthrofibrosis following knee arthroplasty, in whom prior manipulation under anesthesia (MUA) has failed. Typically, nonoperative treatment in these patients has also failed, including aggressive physiotherapy, stretching, dynamic splinting, and various pain-management measures or medications. Range of motion in these patients is often suboptimal, and any gains in flexibility will likely have hit a plateau over many months. The goal of performing lysis of adhesions is to increase the range of motion in patients with knee stiffness following total knee arthroplasty, as well as to reduce pain and restore physiologic function of the knee, enabling activities of daily living. Description: This is a straightforward surgical technique that can be performed in a single stage. The preoperative range of motion is documented after induction of general anesthesia. The procedure begins with the establishment of standard medial and lateral parapatellar arthroscopic portals. A blunt trocar is introduced into the knee, and blunt, manual lysis of adhesions is performed in the suprapatellar pouch and the medial and lateral gutters with use of a sweeping motion after piercing and perforating the scarred adhesive bands or capsular tissue. Next, the arthroscope is inserted into the knee, and a diagnostic arthroscopy is performed. Bands of fibrous tissue are released and resected with use of electrocautery and a 4.0-mm arthroscopic shaver. Next, the posterior cruciate ligament (PCL) is visualized in full flexion. If PCL tightness is observed, the PCL can be released from its femoral origin until the flexion gap is increased. This portion of the procedure can include either partial or full release of the PCL, as indicated. Next, the arthroscope is removed and the ipsilateral hip is flexed to 90° for a standard MUA. Gentle force is applied to the proximal aspect of the tibia, and the knee is flexed. After completing the MUA, immediate post-intervention range of motion of the knee is documented, and the patient is provided with a continuous passive motion (CPM) machine set to the maximum flexion and extension achieved in the operating room. Alternatives: Nonoperative treatment of a stiff knee following total knee arthroplasty is well documented in the current literature. Range of motion has been shown to increase in patients undergoing proper pain management, aggressive physical therapy, and closed MUA in the acute postoperative setting. Additionally, more severe cases of established arthrofibrosis despite prior MUA can be treated with an open lysis of adhesions1-3. Rationale: Arthroscopic lysis of adhesions with PCL release versus resection has been well described previously. This procedure has been shown to benefit patients in whom initial nonoperative treatment has failed. Additionally, this procedure is not limited to the immediate acute postoperative period like standard MUA3. To our knowledge, no technique video has been published outlining arthroscopic lysis of adhesions for a stiff knee following total knee arthroplasty. Expected Outcomes: This procedure has been shown to provide an immediate and lasting improvement in the flexion and extension arc of the knee, as well as improved functional outcomes. Patients should be educated that improvements gained in the operating room must be sustained through physical therapy. In a study of 32 patients who underwent arthroscopic lysis of adhesions for moderately severe arthrofibrosis following a total knee arthroplasty, Jerosch and Aldawoudy reported a mean postoperative flexion of 119° in the operating room and 97° at the time of the latest follow-up. Eight patients with extensor lag showed improvement from 27° to 4°. Average Knee Society scores improved from 70 points preoperatively to 86 points at the time of the latest follow-up4. Their article showed that arthroscopic treatment of stiffness following total knee arthroplasty is a safe and effective form of treatment. Important Tips: Perform manual lysis of adhesions with a trocar prior to inserting the arthroscope in order to improve visualization and access.Utilize all portals and accessory portals interchangeably in order to improve access.Prescribe physical therapy with or without CPM machine immediately following surgery in order to maintain correction.Utilize pump inflow in order to help distend the tightened capsule.Protect the prosthetic surface from scratches during portal establishment.Loss of flexion implies scarring in the suprapatellar pouch and/or intercondylar notch, or PCL tightness.Loss of extension implies a tight posterior capsule, posterior osteophytes, or scarring of the PCL stump.A motorized shaver is the best tool for treatment of dense fibrous tissue, but be sure not to scratch metal total knee components. Acronyms and Abbreviations: TKA = total knee arthroplastyROM = range of motionCT = computed tomographyMRI = magnetic resonance imagingESR = erythrocyte sedimentation rateCRP = C-reactive protein.

10.
Cureus ; 14(11): e31528, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36540432

RESUMO

BACKGROUND: People experiencing homelessness (PEH) are recognized as members of a vulnerable population with significant health and social disparities. Due to the COVID-19 pandemic, these populations are at risk for increased morbidity and mortality. The Herbert Wertheim College of Medicine (HWCOM) of Florida International University (FIU) in collaboration with the Miami-Dade County Homeless Trust presents this case series based on the results of the Telemedicine Homeless Monitoring Project, launched in April 2020. METHODS: Utilizing a faculty-student educational model, medical students at FIU HWCOM called PEH patients residing in isolation hotels on a daily basis to monitor their symptoms using a COVID-19 risk assessment template. Thirty-one PEH patients were followed for the duration of 12 weeks between April 2020 and August 2020. A retrospective chart review was then conducted, and four exemplar patients were chosen, highlighting common themes. Variables in the risk assessment included demographics, comorbidities, past medical history, indications for isolation or quarantine, length of stay, clinical and social needs identified, and qualitative data regarding barriers or successes of the telehealth platform. RESULTS: Thirty-one patients, between the ages of 20 and 84 and with an average age of 50.74, were followed in the program. There were eight females and 23 males in the study. Four exemplar PEH patients were discussed, highlighting the common themes identified; the lack of basic necessities that PEH face, the burden of chronic medical illnesses, a lack of health literacy, the burden of mental illnesses, and the acute stress caused by COVID-19 itself. CONCLUSION: Our research identified numerous characteristics of the homeless population that providers should pay special attention to during the pandemic. The relationship between the Homeless Trust and FIU HWCOM provided medical students with an excellent learning opportunity by letting them participate in clinical care while under lockdown due to the COVID-19 outbreak. Based on the results of the study, we believe that models like this will be useful in the event of a future epidemic.

11.
Front Immunol ; 13: 1006776, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36275650

RESUMO

There is growing concern about the toxicity of colloidal aluminum salts used as adjuvants in subcutaneous allergen immunotherapy (SCIT). Therefore, alternative adjuvants and delivery systems are being explored to replace alum in SCIT. We applied micellar elastin-like polypeptides (ELPs), a type of self-assembling protein, to replace alum as vaccine adjuvant in birch pollen SCIT. ELP and an ELP-Bet v 1 fusion protein were expressed in E. coli and purified by immuno-affinity chromatography and inverse-transition cycling (ITC). Nanoparticles self-assembled from ELP and a 9:1 ELP/ELP-Bet v 1 mixture were characterized by using dynamic light scattering and atomic force microscopy. Allergenicity was assessed by measuring mediator release from rat basophilic leukemia cells transformed with the human FcϵR1 and sensitized with sera derived from human birch pollen allergic patients. Humoral and T-cell immunity were investigated by immunizing naïve mice with the ELP/ELP-Bet v 1 nanoparticles or alum-adsorbed Bet v 1, both containing 36 µg Bet v 1. ELP and ELP/ELP-Bet v 1 self-assembled at 37°C into spherically shaped micelles with a diameter of ~45 nm. ELP conjugation made Bet v 1 hypo-allergenic (10-fold). Compared to alum-adsorbed Bet v 1, ELP/ELP-Bet v 1 nanoparticles induced stronger IgG responses with an earlier onset. Additionally, ELP/ELP-Bet v 1 did not induce Th2 skewing cytokines and IgE. The hypoallergenic character and strong humoral immune response in the absence of a Th2-skewing T-cell response make ELP-based nanoparticles a promising candidate to replace alum in SCIT.


Assuntos
Antígenos de Plantas , Nanopartículas , Ratos , Humanos , Camundongos , Animais , Pólen , Imunoglobulina E , Elastina , Micelas , Escherichia coli , Alumínio , Linfócitos T CD4-Positivos , Sais , Alérgenos , Imunoglobulina G , Peptídeos , Citocinas
12.
Nat Commun ; 13(1): 1920, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35395820

RESUMO

Molecularly thin, nanoporous thin films are of paramount importance in material sciences. Their use in a wide range of applications requires control over their chemical functionalities, which is difficult to achieve using current production methods. Here, the small polycyclic aromatic hydrocarbon decacyclene is used to form molecular thin films, without requiring covalent crosslinking of any kind. The 2.5 nm thin films are mechanically stable, able to be free-standing over micrometer distances, held together solely by supramolecular interactions. Using a combination of computational chemistry and microscopic imaging techniques, thin films are studied on both a molecular and microscopic scale. Their mechanical strength is quantified using AFM nanoindentation, showing their capability of withstanding a point load of 26 ± 9 nN, when freely spanning over a 1 µm aperture, with a corresponding Young's modulus of 6 ± 4 GPa. Our thin films constitute free-standing, non-covalent thin films based on a small PAH.

13.
ACS Mater Au ; 2(2): 79-84, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35295622

RESUMO

In chemical vapor deposition of graphene, crossing over the melting temperature of the bulk catalyst is an effective approach to heal the defects and thus improve the crystallinity of the lattice. Here, electromagnetic absorption (the capability of metals to absorb radiated thermal energy) yields a thin skin of liquid metal catalyst at submelting temperatures, allowing the growth of high quality graphene. In fact, a chromium film initially deposited on one side of a copper foil absorbs the thermal energy radiated from a heating stage several times more effectively than a plain copper foil. The resulting migration of the chromium grains to the other side of the foil locally melts the copper, improving the crystalline quality of the growing graphene, confirmed by Raman spectroscopy. The process duration is therefore dramatically minimized, and the crystallinity of the graphene is maximized. Remarkably, the usual annealing step is no more necessary prior to the growth which together with unlocking the direct healing of defects in the growing graphene, will unify growth strategies between a range of catalysts.

14.
Adv Mater ; 34(7): e2106666, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34994022

RESUMO

Owing to their excellent electrical properties and chemical stability, graphene field-effect transistors (Gr-FET) are extensively studied for biosensing applications. However, hinging on surface interactions of charged biomolecules, the sensitivity of Gr-FET is hampered by ionic screening under physiological conditions with high salt concentrations up to frequencies as high as MHz. Here, an electrolyte-gated Gr-FET in reflectometry mode at ultrahigh frequencies (UHF, around 2 GHz), where the ionic screening is fully cancelled and the dielectric sensitivity of the device allows the Gr-FET to directly function in high-salt solutions, is configured. Strikingly, by simultaneous characterization using electrolyte gating and UHF reflectometry, the developed graphene biosensors offer unprecedented capability for real-time monitoring of dielectric-specified biomolecular/cell interactions/activities, with superior limit of detection compared to that of previously reported nanoscale high-frequency sensors. These achievements highlight the unique potential of ultrahigh-frequency operation for unblocking the true potential of graphene biosensors for point-of-care diagnostic.


Assuntos
Técnicas Biossensoriais , Grafite , Eletrólitos , Grafite/química , Íons , Transistores Eletrônicos
15.
ACS Catal ; 12(1): 173-182, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35028190

RESUMO

The presence of defects and chemical dopants in metal-free carbon materials plays an important role in the electrocatalysis of the oxygen reduction reaction (ORR). The precise control and design of defects and dopants in carbon electrodes will allow the fundamental understanding of activity-structure correlations for tailoring catalytic performance of carbon-based, most particularly graphene-based, electrode materials. Herein, we adopted monolayer graphene - a model carbon-based electrode - for systematical introduction of nitrogen and oxygen dopants, together with vacancy defects, and studied their roles in catalyzing ORR. Compared to pristine graphene, nitrogen doping exhibited a limited effect on ORR activity. In contrast, nitrogen doping in graphene predoped with vacancy defects or oxygen enhanced the activities at 0.4 V vs the reversible hydrogen electrode (RHE) by 1.2 and 2.0 times, respectively. The optimal activity was achieved for nitrogen doping in graphene functionalized with oxygenated defects, 12.8 times more than nitrogen-doped and 7.7 times more than pristine graphene. More importantly, oxygenated defects are highly related to the 4e- pathway instead of nitrogen dopants. This work indicates a non-negligible contribution of oxygen and especially oxygenated vacancy defects for the catalytic activity of nitrogen-doped graphene.

16.
Med Sci Educ ; 31(4): 1287-1290, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34457971

RESUMO

Augmenting its nutrition education, the Herbert Wertheim College of Medicine Endocrinology course initially used a case-based, take-home assignment on type II diabetes dietary guidelines, with literature search requirement and a module on relevant social determinants of health (SDOH). Course evaluations indicated this assignment did not adequately improve student perceptions of learning. For the subsequent cohort, we changed to a large-group active learning session, requiring one faculty facilitator, where student teams created problem lists including SDOH and reviewed research articles to support evidence-based nutrition recommendations. Survey results indicate that the new session resulted in significantly improved student perceptions of learning. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40670-021-01342-7.

18.
J Health Care Poor Underserved ; 32(2): 598-606, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34120960

RESUMO

In response to the COVID-19 pandemic, the Herbert Wertheim College of Medicine's Neighborhood Health Education Learning Program (NeighborhoodHELP) initiated a longitudinal assessment and mitigation of social and health care challenges for a population of approximately 850 underserved households. Here, we describe the needs assessment, ensuing interventions, and lessons learned during this pandemic.


Assuntos
COVID-19/epidemiologia , Avaliação das Necessidades , Populações Vulneráveis , Adolescente , Adulto , Idoso , Criança , Serviços de Saúde Comunitária , Informação de Saúde ao Consumidor , Feminino , Florida/epidemiologia , Assistência Alimentar , Necessidades e Demandas de Serviços de Saúde , Humanos , Masculino , Área Carente de Assistência Médica , Pessoa de Meia-Idade , Pandemias , Determinantes Sociais da Saúde , Adulto Jovem
19.
Cureus ; 13(3): e13857, 2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33859907

RESUMO

Estimates place low intake of fruits and vegetables, physical inactivity, and high BMI (overweight-obesity) as all in the top 12 causes of death. Food and dietary education are becoming a focus in how we approach disease prevention and management, and food prescription programs in particular are showing promise, especially in under-resourced, food-insecure communities. This paper describes a pilot food prescription program in a handful of uninsured patients enrolled in an interprofessional clinical and educational program of a medical school in South Florida. This case series of four patients struggling with food insecurity profiles the demographic and clinical characteristics of the participants and provides the results of standardized assessments of their dietary behaviors, physical activity levels, and attitudes toward food before and after the intervention. This four-month pilot food prescription program, Fresh Start Food Rx, involved a prospective case report of four patients seen on a mobile health center (MHC) for uninsured patients in South Miami, Florida. The MHC is part of an interprofessional health professions education, health care, and social service program of the Herbert Wertheim College of Medicine at Florida International University called the Neighborhood Health Education Learning Program (NeighborhoodHELP). A systematic review of South Miami MHC patient electronic medical records identified eligible participants for the program: patients with food insecurity and a BMI >30, with comorbid health conditions. Patients with greater BMI and more comorbidities were prioritized. Once enrolled, we provided biweekly packages of fresh fruits and vegetables along with monthly dietary education to the participants. Key measures included self-reported fruit and vegetable consumption, attitude toward healthy eating, and level of activity. Pre- and post-intervention focus groups assessed barriers the participants faced to eating healthy and pursuing physical activity, satisfaction with the program, feedback on strengths and weaknesses, and anticipated behavioral changes after completion of the program. Prior to the intervention, participants reported eating fruits on an average of 4.5 days out of the week. Post-survey answers increased to 5.0 days per week. Though the average amount of days per week that participants reported eating vegetables decreased slightly, the average number of vegetable servings that participants reported eating in a week increased. At termination of the program, most participants agreed that a diet rich in fruits and vegetables is good for you, that it is important to eat fruits and vegetables every day, and that a diet rich in fruits and vegetables can protect against cancer. This case study demonstrates that easier access to healthy foods, such as fresh produce delivery, and regular health education have the potential to promote healthier attitudes toward foods like fruits and vegetables. This change in attitude can then influence behavior, such as choosing to try new produce or increasing the amount and frequency of produce consumption. With the lessons learned from this small pilot program, the authors helped facilitate the expansion of a larger food prescription program in conjunction with a community partner hospital in the area. Findings from this experience might prove useful for others attempting to develop or expand a food prescription and health education program of their own.

20.
Langmuir ; 37(14): 4049-4055, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33651625

RESUMO

Interactions between water and graphene can be probed on a macroscopic level through wettability by measuring the water contact angle and on a microscopic level through water desorption kinetic studies using surface science methods. The contact angle studies of graphene pinpointed the critical role of sample preparation and measurement conditions in assessing the wettability of graphene. So far, studies of water desorption from graphene under the conditions of ultrahigh vacuum provided superior control over the environment but disregarded the importance of sample preparation. Here, we systematically examined the effect of the morphology of the growth substrate and of the transfer process on the macroscopic and microscopic wettability of graphene. Remarkably, the macroscopic wetting transparency of graphene does not always translate into microscopic wetting transparency, particularly in the case of an atomically defined Cu(111) substrate. Additionally, subtle differences in the type of substrates significantly alter the interactions between graphene and the first monolayer of adsorbed water but have a negligible effect on the apparent macroscopic wettability. This work looks into the correlations between the wetting properties of graphene, both on the macroscopic and microscopic scales, and highlights the importance of sample preparation in understanding the surface chemistry of graphene.

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