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1.
Arch Phys Med Rehabil ; 103(4): 755-763, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34058154

RESUMO

OBJECTIVE: To characterize the use of complementary and integrative health care (CIH) by people with spinal cord injury. DESIGN: Cross-sectional self-report study. SETTING: Participants were recruited from 5 Spinal Cord Injury Model Systems (SCIMS) centers across the United States. INTERVENTIONS: Not applicable. PARTICIPANTS: A total of 411 persons enrolled in the SCIMS completing their SCIMS follow-up interview between January 2017 and July 2019 (N = 411). MAIN OUTCOME MEASURES: Participants completed a survey developed for this study that included questions about types of CIH currently and previously used, reasons for current and previous use, reasons for discontinuing use of CIH, and reasons for never using CIH since injury. RESULTS: Of the 411 respondents, 80.3% were current or previous users of CIH; 19.7% had not used CIH since injury. The most commonly used current types of CIH were multivitamins (40.0%) and massage (32.6%), whereas the most common previously used type of CIH was acupuncture (33.9%). General health and wellness (61.4%) and pain (31.2%) were the most common reasons for using CIH. The primary reason for discontinuing CIH was that it was not helpful (42.1%). The primary reason for not using CIH since injury was not knowing what options are available (40.7%). CONCLUSIONS: These results point to the importance for rehabilitation clinicians to be aware that their patients may be using 1 or more CIH approaches. Providers should be open to starting a dialogue to ensure the health and safety of their patients because there is limited information on safety and efficacy of CIH approaches in this population. These results also set the stage for further analysis of this data set to increase our knowledge in this area.


Assuntos
Terapias Complementares , Traumatismos da Medula Espinal , Terapias Complementares/métodos , Estudos Transversais , Atenção à Saúde , Humanos , Inquéritos e Questionários , Estados Unidos
2.
J Clin Ultrasound ; 50(9): 1271-1278, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36200639

RESUMO

PURPOSE: To evaluate the diagnostic performance of lung ultrasound (LUS) in screening for SARS-CoV-2 infection in patients requiring surgery. METHODS: Patients underwent a LUS protocol that included a scoring system for screening COVID-19 pneumonia as well as RT-PCR test for SARS-CoV-2. The receiver operator characteristic (ROC) curve was determined for the relationship between LUS score and PCR test results for COVID-19. The optimal threshold for the best discrimination between non-COVID-19 patients and COVID-19 patients was calculated. RESULTS: Among 203 patients enrolled (mean age 48 years; 82 males), 8.3% were COVID-19-positive; 4.9% were diagnosed via the initial RT-PCR test. Of the patients diagnosed with SARS-CoV-2, 64.7% required in-hospital management and 17.6% died. The most common ultrasound findings were B lines (19.7%) and a thickened pleura (19.2%). The AUC of the ROC curve of the relationship of LUS score with a cutoff value >8 versus RT-PCR test for the assessment of SARS-CoV-2 pneumonia was 0.75 (95% CI 0.61-0.89; sensitivity 52.9%; specificity 91%; LR (+) 6.15, LR (-) 0.51). CONCLUSION: The LUS score in surgical patients is not a useful tool for screening patients with potential COVID-19 infection. LUS score shows a high specificity with a cut-off value of 8.


Assuntos
COVID-19 , Masculino , Humanos , Pessoa de Meia-Idade , SARS-CoV-2 , Pulmão/diagnóstico por imagem , Teste para COVID-19 , Ultrassonografia/métodos
3.
Sensors (Basel) ; 21(22)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34833764

RESUMO

Passive monitoring techniques have been used for peak temperature measurements during irradiation tests by exploiting the melting point of well-characterized materials. Recent efforts to expand the capabilities of such peak temperature detection instrumentation include the development and testing of additively manufactured (AM) melt wires. In an effort to demonstrate and benchmark the performance and reliability of AM melt wires, we conducted a study to compare prototypical standard melt wires to an AM melt wire capsule, composed of printed aluminum, zinc, and tin melt wires. The lowest melting-point material used was Sn, with a melting point of approximately 230 °C, Zn melts at approximately 420 °C, and the high melting-point material was aluminum, with an approximate melting point of 660 °C. Through differential scanning calorimetry and furnace testing we show that the performance of our AM melt wire capsule was consistent with that of the standard melt-wire capsule, highlighting a path towards miniaturized peak-temperature sensors for in-pile sensor applications.


Assuntos
Alumínio , Reprodutibilidade dos Testes , Temperatura
4.
Sensors (Basel) ; 20(19)2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33023160

RESUMO

Graphene and carbon nanotube (CNT)-based gas/vapor sensors have gained much traction for numerous applications over the last decade due to their excellent sensing performance at ambient conditions. Inkjet printing various forms of graphene (reduced graphene oxide or modified graphene) and CNT (single-wall nanotubes (SWNTs) or multiwall nanotubes (MWNTs)) nanomaterials allows fabrication onto flexible substrates which enable gas sensing applications in flexible electronics. This review focuses on their recent developments and provides an overview of the state-of-the-art in inkjet printing of graphene and CNT based sensors targeting gases, such as NO2, Cl2, CO2, NH3, and organic vapors. Moreover, this review presents the current enhancements and challenges of printing CNT and graphene-based gas/vapor sensors, the role of defects, and advanced printing techniques using these nanomaterials, while highlighting challenges in reliability and reproducibility. The future potential and outlook of this rapidly growing research are analyzed as well.

5.
Int J Mol Sci ; 21(6)2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32244989

RESUMO

The Center of Biomedical Research Excellence in Matrix Biology strives to improve our understanding of extracellular matrix at molecular, cellular, tissue, and organismal levels to generate new knowledge about pathophysiology, normal development, and regenerative medicine. The primary goals of the Center are to i) support junior investigators, ii) enhance the productivity of established scientists, iii) facilitate collaboration between both junior and established researchers, and iv) build biomedical research infrastructure that will support research relevant to cell-matrix interactions in disease progression, tissue repair and regeneration, and v) provide access to instrumentation and technical support. A Pilot Project program provides funding to investigators who propose applying their expertise to matrix biology questions. Support from the National Institute of General Medical Sciences at the National Institutes of Health that established the Center of Biomedical Research Excellence in Matrix Biology has significantly enhanced the infrastructure and the capabilities of researchers at Boise State University, leading to new approaches that address disease diagnosis, prevention, and treatment. New multidisciplinary collaborations have been formed with investigators who may not have previously considered how their biomedical research programs addressed fundamental and applied questions involving the extracellular matrix. Collaborations with the broader matrix biology community are encouraged.


Assuntos
Pesquisa Biomédica , Comportamento Cooperativo , Matriz Extracelular/metabolismo , Pesquisadores , Comitês Consultivos , Escolha da Profissão , Humanos , Estudantes
6.
Am Heart J ; 214: 142-155, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31203159

RESUMO

BACKGROUND: Glomerular filtration rate is a key physiologic variable with a central role in clinical decision making and a strong association with prognosis in diverse populations. Reduced estimated glomerular filtration rate (eGFR) is common among adults with congenital heart disease (ACHD). METHODS: We conducted a prospective cohort study of outpatient ACHD ≥18 years old seen in 2012-2017. Creatinine and cystatin C were measured; eGFR was calculated using either the creatinine or cystatin C Chronic Kidney Disease-Epidemiology Collaboration equation (CKD-EPICr and CKD-EPICysC, respectively). Survival analysis was performed to define the relationship between eGFR and both all-cause mortality and a composite outcome of death or nonelective cardiovascular hospitalization. RESULTS: Our cohort included 911 ACHD (39 ±â€¯14 years old, 49% female). Mean CKD-EPICr and CKD-EPICysC were similar (101 ±â€¯20 vs 100 ±â€¯23 mL/min/1.73 m2), but CKD-EPICr estimates were higher for patients with a Fontan circulation (n = 131, +10 ±â€¯19 mL/min/1.73 m2). After mean follow-up of 659 days, 128 patients (14.1%) experienced the composite outcome and 31 (3.4%) died. CKD-EPICysC more strongly predicted all-cause mortality (eGFR <60 vs >90 mL/min/1.73 m2: CKD-EPICysC unadjusted HR = 20.2 [95% CI 7.6-53.1], C-statistic = 0.797; CKD-EPICr unadjusted HR = 4.6 [1.7-12.7], C-statistic = 0.620). CKD-EPICysC independently predicted the composite outcome, whereas CKD-EPICr did not (CKD-EPICysC adjusted HR = 3.0 [1.7-5.3]; CKD-EPICr adjusted HR = 1.5 [0.8-3.1]). Patients reclassified to a lower eGFR category by CKD-EPICysC, compared with CKD-EPICr, were at increased risk for the composite outcome (HR = 2.9 [2.0-4.3], P < .0001); those reclassified to a higher eGFR class were at lower risk (HR = 0.5 [0.3-0.9], P = .03). CONCLUSIONS: Cystatin C-based eGFR more strongly predicts clinical events than creatinine-based eGFR in ACHD. Creatinine-based methods appear particularly questionable in the Fontan circulation.


Assuntos
Creatinina/sangue , Cistatina C/sangue , Taxa de Filtração Glomerular , Cardiopatias Congênitas/sangue , Cardiopatias Congênitas/fisiopatologia , Adulto , Biomarcadores/sangue , Causas de Morte , Feminino , Cardiopatias Congênitas/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Insuficiência Renal Crônica/sangue
7.
Dis Colon Rectum ; 59(6): 493-500, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27145305

RESUMO

BACKGROUND: Current quality-monitoring initiatives do not accurately evaluate surgical site infections based on type of surgical procedure. OBJECTIVE: This study aimed to characterize the effect of the anatomical site resected (right, left, rectal) on wound complications, including superficial, deep, and organ space surgical site infections, in patients who have cancer. SETTINGS: Data were retrieved from the American College of Surgeons National Surgical Quality Improvement Program database. DESIGN: This study was designed to determine the independent risk associated with the anatomical location of cancer resection for all subtypes of surgical site infection. Statistical methods included the Fisher exact test, the χ test, and univariable and multivariable analyses for each outcome of interest. PATIENTS: All colon and rectal resections for colorectal cancer between 2006 and 2012 were selected. Included were 45,956 patients: 17,993 (39.2%) underwent right colectomy, 11,538 (25.1%) underwent left colectomy, and 16,425 (35.7%) underwent rectal resections. RESULTS: The overall surgical site infection rate was 12.3%: 3.7% organ space, 1.4% deep, and 7.2% superficial. On multivariable analysis, rectal resection was associated with the greatest odds of overall surgical site infections in comparison with left- or right-sided resections (rectal OR, 1.51; 95% CI, 1.35-1.69 vs left OR, 1.09; 95% CI, 0.97-1.23 vs right OR, 1). Rectal resections were also associated with greater odds of developing a deep surgical site infection than either right (rectal OR, 1.45; 95% CI, 1.06-1.99) or left (OR, 0.89; 95% CI, 0.62-1.27). The likelihood of organ space surgical site infection followed a similar pattern (rectal OR, 1.83; 95% CI 1.49-2.25; left colon, OR, 0.95; 95% CI, 0.75-1.19). Rectal and left resections had increased odds of superficial surgical site infections compared with right resections (rectal OR, 1.31; 95% CI, 1.14-1.51; left OR, 1.19; 95% CI, 1.03-1.37). LIMITATIONS: This is a retrospective observational study. CONCLUSIONS: Rectal resections for cancer are independently associated with an increased likelihood of superficial, deep, and organ space infections. The policy on surgical site infections as a quality measure currently in place requires modification to adjust for the location of pathology and, hence, the anatomical segment resected when assessing the risk for type of surgical site infection.


Assuntos
Colectomia , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Reto/cirurgia , Infecção da Ferida Cirúrgica/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colectomia/métodos , Bases de Dados Factuais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Retrospectivos , Fatores de Risco
8.
Nano Lett ; 15(7): 4532-40, 2015 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-26035002

RESUMO

Graphene has served as the model 2D system for over a decade, and the effects of grain boundaries (GBs) on its electrical and mechanical properties are very well investigated. However, no direct measurement of the correlation between thermal transport and graphene GBs has been reported. Here, we report a simultaneous comparison of thermal transport in supported single crystalline graphene to thermal transport across an individual graphene GB. Our experiments show that thermal conductance (per unit area) through an isolated GB can be up to an order of magnitude lower than the theoretically anticipated values. Our measurements are supported by Boltzmann transport modeling which uncovers a new bimodal phonon scattering phenomenon initiated by the GB structure. In this novel scattering mechanism, boundary roughness scattering dominates the phonon transport in low-mismatch GBs, while for higher mismatch angles there is an additional resistance caused by the formation of a disordered region at the GB. Nonequilibrium molecular dynamics simulations verify that the amount of disorder in the GB region is the determining factor in impeding thermal transport across GBs.

9.
Ann Surg ; 262(3): 416-25; discussion 423-5, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26258310

RESUMO

OBJECTIVES: To clarify whether bowel preparation use or its individual components [mechanical bowel preparation (MBP)/oral antibiotics] impact specific outcomes after colorectal surgery. METHODS: National Surgical Quality Improvement Program-targeted colectomy data initiated in 2012 capture information on the use/type of bowel preparation and colorectal-specific complications. For patients undergoing elective colorectal resection, the impact of preoperative MBP and antibiotics (MBP+/ABX+), MBP alone (MBP+/ABX-), and no bowel preparation (no-prep) on outcomes, particularly anastomotic leak, surgical site infection (SSI), and ileus, were evaluated using unadjusted/adjusted logistic regression analysis. RESULTS: Of 8442 patients, 2296 (27.2%) had no-prep, 3822 (45.3%) MBP+/ABX-, and 2324 (27.5%) MBP+/ABX+. Baseline characteristics were similar; however, there were marginally more patients with prior sepsis, ascites, steroid use, bleeding disorders, and disseminated cancer in no-prep. MBP with or without antibiotics was associated with reduced ileus [MBP+/ABX+: odds ratio (OR) = 0.57, 95% confidence interval (CI): 0.48-0.68; MBP+/ABX-: OR = 0.78, 95% CI: 0.68-0.91] and SSI [MBP+/ABX+: OR = 0.39, 95% CI: 0.32-0.48; MBP+/ABX-: OR = 0.80, 95% CI: 0.69-0.93] versus no-prep. MBP+/ABX+ was also associated with lower anastomotic leak rate than no-prep [OR = 0.45 (95% CI: 0.32-0.64)]. On multivariable analysis, MBP with antibiotics, but not without, was independently associated with reduced anastomotic leak (OR = 0.57, 95% CI: 0.35-0.94), SSI (OR = 0.40, 95% CI: 0.31-0.53), and postoperative ileus (OR = 0.71, 95% CI: 0.56-0.90). CONCLUSIONS: These data clarify the near 50-year debate whether bowel preparation improves outcomes after colorectal resection. MBP with oral antibiotics reduces by nearly half, SSI, anastomotic leak, and ileus, the most common and troublesome complications after colorectal surgery.


Assuntos
Fístula Anastomótica/prevenção & controle , Antibacterianos/administração & dosagem , Colectomia/efeitos adversos , Íleus/prevenção & controle , Infecção da Ferida Cirúrgica/prevenção & controle , Irrigação Terapêutica/métodos , Administração Oral , Idoso , Antibioticoprofilaxia , Catárticos/administração & dosagem , Colectomia/métodos , Cirurgia Colorretal/efeitos adversos , Cirurgia Colorretal/métodos , Terapia Combinada , Bases de Dados Factuais , Procedimentos Cirúrgicos Eletivos/efeitos adversos , Procedimentos Cirúrgicos Eletivos/métodos , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Resultado do Tratamento
10.
Nano Lett ; 13(12): 5844-50, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24215439

RESUMO

The performance of carbon nanotube network (CNN) devices is usually limited by the high resistance of individual nanotube junctions (NJs). We present a novel method to reduce this resistance through a nanoscale chemical vapor deposition (CVD) process. By passing current through the devices in the presence of a gaseous CVD precursor, localized nanoscale Joule heating induced at the NJs stimulates the selective and self-limiting deposition of metallic nanosolder. The effectiveness of this nanosoldering process depends on the work function of the deposited metal (here Pd or HfB2), and it can improve the on/off current ratio of a CNN device by nearly an order of magnitude. This nanosoldering technique could also be applied to other device types where nanoscale resistance components limit overall device performance.


Assuntos
Nanotecnologia , Nanotubos de Carbono/química , Metais/química , Propriedades de Superfície , Temperatura
11.
ACS Omega ; 9(1): 1614-1619, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222600

RESUMO

Pebble beds have been employed in thermal storage and energy systems, where they are typically used to promote heat exchange in high-temperature environments. Understanding the heat conduction of the entire pebble bed could aid in the material selection of the pebbles themselves and structural components, system design, and safety monitoring. However, the thermal conductivity of pebble beds can change significantly near geometric boundaries. Using a complex multilayer analytical model in conjunction with a line source probe, we found a substantial increase in the thermal conductivity of a sintered bauxite pebble bed in the near-wall region (7.6 W m-1 K-1) compared to the bulk (0.59 W m-1 K-1). We investigated this difference by comparing porosity results, acquired with micro-CT, of 33.18 and 33.31% at approximately one pebble width surrounding the probe (near-wall) and the bulk of the pebble bed, suggesting that the thermal conductivity is largely altered by thermal contact resistance in the near-wall regime.

12.
Small Methods ; : e2301596, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470204

RESUMO

Printed electronics have made remarkable progress in recent years and inkjet printing (IJP) has emerged as one of the leading methods for fabricating printed electronic devices. However, challenges such as nozzle clogging, and strict ink formulation constraints have limited their widespread use. To address this issue, a novel nozzle-free printing technology is explored, which is enabled by laser-generated focused ultrasound, as a potential alternative printing modality called Shock-wave Jet Printing (SJP). Specifically, the performance of SJP-printed and IJP-printed bottom-gated carbon nanotube (CNT) thin film transistors (TFTs) is compared. While IJP required ten print passes to achieve fully functional devices with channel dimensions ranging from tens to hundreds of micrometers, SJP achieved comparable performance with just a single pass. For optimized devices, SJP demonstrated six times higher maximum mobility than IJP-printed devices. Furthermore, the advantages of nozzle-free printing are evident, as SJP successfully printed stored and unsonicated inks, delivering moderate electrical performance, whereas IJP suffered from nozzle clogging due to CNT agglomeration. Moreover, SJP can print significantly longer CNTs, spanning the entire range of tube lengths of commercially available CNT ink. The findings from this study contribute to the advancement of nanomaterial printing, ink formulation, and the development of cost-effective printable electronics.

13.
ACS Appl Electron Mater ; 6(2): 748-760, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38435803

RESUMO

Aerosol jet printing (AJP) is an advanced manufacturing technique for directly writing nanoparticle inks onto target substrates. It is an emerging reliable, efficient, and environmentally friendly fabrication route for thin film electronics and advanced semiconductor packaging. This fabrication technique is highly regarded for its rapid prototyping, the flexibility of design, and fine feature resolution. Nickel is an attractive high-temperature packaging material due to its electrical conductivity, magnetism, and corrosion resistance. In this work, we synthesized nickel nanoparticles and formulated an AJP ink, which was printed on various material surfaces. Thermal sintering experiments were performed on the samples to explore the redox behavior and to optimize the electrical performance of the devices. The nickel devices were heated to failure under an argon atmosphere, which was marked by a loss of reflectance and electrical properties due to the dewetting of the films. Additionally, a reduction mechanism was observed from these studies, which resembled that of nucleation and coalescence. Finally, multilayer graphene was grown on a custom-printed nickel thin film using chemical vapor deposition (CVD), establishing a fully additive manufacturing route to patterned graphene.

14.
ACS Mater Au ; 4(1): 65-73, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38221917

RESUMO

Conductive and biofriendly gold nanomaterial inks are highly desirable for printed electronics, biosensors, wearable electronics, and electrochemical sensor applications. Here, we demonstrate the scalable synthesis of stable gold nanoparticle inks with low-temperature sintering using simple chemical processing steps. Multiprinter compatible aqueous gold nanomaterial inks were formulated, achieving resistivity as low as ∼10-6 Ω m for 400 nm thick films sintered at 250 °C. Printed lines with a resolution of <20 µm and minimal overspray were obtained using an aerosol jet printer. The resistivity of the printed patterns reached ∼9.59 ± 1.2 × 10-8 Ω m after sintering at 400 °C for 45 min. Our aqueous-formulated gold nanomaterial inks are also compatible with inkjet printing, extending the design space and manufacturability of printed and flexible electronics where metal work functions and chemically inert films are important for device applications.

15.
Nanotechnology ; 24(40): 405204, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24029606

RESUMO

The high field properties of carbon nanotube (CNT) network thin film transistors (CN-TFTs) are important for their practical operation, and for understanding their reliability. Using a combination of experimental and computational techniques we show how the channel geometry (length L(C) and width W(C)) and network morphology (average CNT length L(t) and alignment angle distribution θ) affect heat dissipation and high field breakdown in such devices. The results suggest that when WC ≥ L(t), the breakdown voltage remains independent of W(C) but varies linearly with L(C). The breakdown power varies almost linearly with both W(C) and L(C) when WC >> L(t). We also find that the breakdown power is more susceptible to the variability in the network morphology compared to the breakdown voltage. The analysis offers new insight into the tunable heat dissipation and thermal reliability of CN-TFTs, which can be significantly improved through optimization of the network morphology and device geometry.

17.
Microsyst Nanoeng ; 9: 51, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37152863

RESUMO

Surface acoustic wave (SAW) devices are a subclass of micro-electromechanical systems (MEMS) that generate an acoustic emission when electrically stimulated. These transducers also work as detectors, converting surface strain into readable electrical signals. Physical properties of the generated SAW are material dependent and influenced by external factors like temperature. By monitoring temperature-dependent scattering parameters a SAW device can function as a thermometer to elucidate substrate temperature. Traditional fabrication of SAW sensors requires labor- and cost- intensive subtractive processes that produce large volumes of hazardous waste. This study utilizes an innovative aerosol jet printer to directly write consistent, high-resolution, silver comb electrodes onto a Y-cut LiNbO3 substrate. The printed, two-port, 20 MHz SAW sensor exhibited excellent linearity and repeatability while being verified as a thermometer from 25 to 200 ∘C. Sensitivities of the printed SAW thermometer are - 96.9 × 1 0 - 6 ∘ C-1 and - 92.0 × 1 0 - 6 ∘ C-1 when operating in pulse-echo mode and pulse-receiver mode, respectively. These results highlight a repeatable path to the additive fabrication of compact high-frequency SAW thermometers.

18.
bioRxiv ; 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36993602

RESUMO

Three-dimensional (3D) tissue engineering (TE) is a prospective treatment that can be used to restore or replace damaged musculoskeletal tissues such as articular cartilage. However, current challenges in TE include identifying materials that are biocompatible and have properties that closely match the mechanical properties and cellular environment of the target tissue, while allowing for 3D tomography of porous scaffolds as well as their cell growth and proliferation characterization. This is particularly challenging for opaque scaffolds. Here we use graphene foam (GF) as a 3D porous biocompatible substrate which is scalable, reproduceable, and a suitable environment for ATDC5 cell growth and chondrogenic differentiation. ATDC5 cells are cultured, maintained, and stained with a combination of fluorophores and gold nanoparticle to enable correlative microscopic characterization techniques, which elucidate the effect of GF properties on cell behavior in a three-dimensional environment. Most importantly, our staining protocols allows for direct imaging of cell growth and proliferation on opaque GF scaffolds using X-ray MicroCT, including imaging growth of cells within the hollow GF branches which is not possible with standard fluorescence and electron microscopy techniques.

19.
Nanoscale ; 15(14): 6596-6606, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36916135

RESUMO

Thermoelectric generators (TEGs) convert temperature differences into electrical power and are attractive among energy harvesting devices due to their autonomous and silent operation. While thermoelectric materials have undergone substantial improvements in material properties, a reliable and cost-effective fabrication method suitable for microgravity and space applications remains a challenge, particularly as commercial space flight and extended crewed space missions increase in frequency. This paper demonstrates the use of plasma-jet printing (PJP), a gravity-independent, electromagnetic field-assisted printing technology, to deposit colloidal thermoelectric nanoflakes with engineered nanopores onto flexible substrates at room temperature. We observe substantial improvements in material adhesion and flexibility with less than 2% and 11% variation in performance after 10 000 bending cycles over 25 mm and 8 mm radii of curvature, respectively, as compared to previously reported TE films. Our printed films demonstrate electrical conductivity of 2.5 × 103 S m-1 and a power factor of 70 µW m-1 K-2 at room temperature. To our knowledge, these are the first reported values of plasma-jet printed thermoelectric nanomaterial films. This advancement in plasma jet printing significantly promotes the development of nanoengineered 2D and layered materials not only for energy harvesting but also for the development of large-scale flexible electronics and sensors for both space and commercial applications.

20.
ACS Appl Bio Mater ; 6(9): 3717-3725, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37655758

RESUMO

Three-dimensional (3D) tissue engineering (TE) is a prospective treatment that can be used to restore or replace damaged musculoskeletal tissues, such as articular cartilage. However, current challenges in TE include identifying materials that are biocompatible and have properties that closely match the mechanical properties and cellular microenvironment of the target tissue. Visualization and analysis of potential 3D porous scaffolds as well as the associated cell growth and proliferation characteristics present additional problems. This is particularly challenging for opaque scaffolds using standard optical imaging techniques. Here, we use graphene foam (GF) as a 3D porous biocompatible substrate, which is scalable, reproducible, and a suitable environment for ATDC5 cell growth and chondrogenic differentiation. ATDC5 cells are cultured, maintained, and stained with a combination of fluorophores and gold nanoparticles to enable correlative microscopic characterization techniques, which elucidate the effect of GF properties on cell behavior in a 3D environment. Most importantly, the staining protocol allows for direct imaging of cell growth and proliferation on opaque scaffolds using X-ray MicroCT, including imaging growth of cells within the hollow GF branches, which is not possible with standard fluorescence and electron microscopy techniques.


Assuntos
Grafite , Nanopartículas Metálicas , Ouro , Engenharia Tecidual , Técnicas de Cultura de Células em Três Dimensões , Imagem Óptica
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