ABSTRACT
Pembrolizumab has shown significant anticancer effects against various human cancers. The present study investigated the effects of pembrolizumab liposome and nano (naked) forms in treated lymphocytes from head and neck squamous cell carcinoma (HNSCC) patients compared to healthy individuals. The level of oxidative DNA damage induced by hydrogen peroxide (H2O2) was also investigated. A concentration of 10 µg/ml of pembrolizumab liposome was used to treat the lymphocytes in the Comet and micronucleus assays based on the preliminary dosage optimization tests. To determine the cellular pathways involved in the protective role of pembrolizumab against H2O2, several proteins involved in apoptosis (P53, P21 and Bcl-2) were assessed. Pembrolizumab significantly reduced DNA damage and decreased the number of micronuclei in lymphocytes from HNSCC patients (p < 0.01) compared with healthy individuals. The 10 µg/ml of pembrolizumab liposome significantly reduced the oxidative stress induced by H2O2 and was effective in healthy and HNSCC groups using the Comet and micronucleus assays (p < 0.001). To our knowledge, this is the first report of pembrolizumab in liposome and naked forms exhibiting a protective effect on DNA damage in the treatment of HNSCC patients.
Subject(s)
Antibodies, Monoclonal, Humanized , Head and Neck Neoplasms , Liposomes , Humans , Squamous Cell Carcinoma of Head and Neck/drug therapy , Head and Neck Neoplasms/drug therapy , Hydrogen Peroxide , LymphocytesABSTRACT
Correction for 'Synthesis of vertically aligned carbon nanotube arrays on polyhedral Fe/Al2O3 catalysts' by Jun Liu et al., Chem. Commun., 2011, 47, 6434-6436, https://doi.org/10.1039/C1CC10878F.
ABSTRACT
BACKGROUND: Loss to follow-up is an under-recognised problem in primary care. Continuity with a primary care provider improves morbidity and mortality in the Veterans Health Administration. We sought to reduce the percentage of patients lost to follow-up at the Northeast Ohio Veterans Affairs Healthcare System from October 2017 to March 2019. METHODS: The Panel Retention Tool (PRT) was developed and tested with primary care teams using multiple Plan, Do, Study and Act cycles to identify and schedule lost to follow-up patients. Baseline data on loss to follow-up, defined as the percentage of panelled patients not seen in primary care in the past year, was collected over 6 months during tool development. Outcomes were tracked from implementation through spread and sustainment (12 months) across 14 primary care clinics. RESULTS: Of the 96 170 panelled patients at the beginning of the study period, 2715 (2.8%) were found to be inactive and removed from provider panels, improving panel reliability. Among the remaining, 1856 (1.9%) patients without scheduled follow-up were scheduled for future care, and 1239 (1.3%) without recent prior care completed encounters during the study period. The percentage of patients lost to follow-up decreased from 10.1% (lower control limit (LCL) 9.8%-upper control limit (UCL) 10.4%) at baseline to 6.4% (LCL 6.2%-UCL 6.7%) postintervention and patients without planned future care decreased from 21.7% (LCL 21.3%-UCL 22.1%) to 17.1% (LCL 16.7%-UCL 17.5%). CONCLUSIONS: The PRT allowed primary care teams in an integrated health system to identify and schedule lost to follow-up patients. Ease of use, adaptability and encouraging outcomes facilitated spread. This has the potential to contribute to more appropriate utilisation of healthcare resources and improved access to primary care.
Subject(s)
Primary Health Care , Quality Improvement , Humans , Ohio , Reproducibility of Results , United States , United States Department of Veterans Affairs , VeteransABSTRACT
This article describes a brief learning activity that provided reflective time to identify barriers, facilitators, and action steps to ensure quality improvement (QI) project success. Learners from our program participated in an interactive 90-minute session that used Liberating Structures to reflect on current barriers to implementation of their QI projects. Analysis of the individual reflective cards identified 10 barriers to QI success. Facilitators were grouped into 16 themes. Action steps were placed into six categories. Integration of reflection promotes important identification of QI project barriers, facilitators, and the creation of action steps.
Subject(s)
Education, Nursing , Quality Improvement , Humans , LearningABSTRACT
The capture and storage of CO2 have been suggested as an effective strategy to reduce the global emissions of greenhouse gases. Hence, in recent years, many studies have been carried out to develop highly efficient materials for capturing CO2 . Until today, different types of porous materials, such as zeolites, porous carbons, N/B-doped porous carbons or metal-organic frameworks (MOFs), have been studied for CO2 capture. Herein, the CO2 capture performance of new hybrid materials, graphene-organic frameworks (GOFs) is described. The GOFs were synthesized under mild conditions through a solvothermal process using graphene oxide (GO) as a starting material and benzene 1,4-diboronic acid as an organic linker. Interestingly, the obtained GOF shows a high surface area (506â m2 g-1 ) which is around 11 times higher than that of GO (46â m2 g-1 ), indicating that the organic modification on the GO surface is an effective way of preparing a porous structure using GO. Our synthetic approach is quite simple, facile, and fast, compared with many other approaches reported previously. The synthesized GOF exhibits a very large CO2 capacity of 4.95â mmol g-1 at 298â K (1â bar), which is higher those of other porous materials or carbon-based materials, along with an excellent CO2 /N2 selectivity of 48.8.
ABSTRACT
Raman spectroscopy is among the primary techniques for the characterisation of graphene materials, as it provides insights into the quality of measured graphenes including their structure and conductivity as well as the presence of dopants. However, our ability to draw conclusions based on such spectra is limited by a lack of understanding regarding the origins of the peaks. Consequently, traditional characterisation techniques, which estimate the quality of the graphene material using the intensity ratio between the D and the G peaks, are unreliable for both GO and rGO. Herein we reanalyse the Raman spectra of graphenes and show that traditional methods rely upon an apparent G peak which is in fact a superposition of the G and D' peaks. We use this understanding to develop a new Raman characterisation method for graphenes that considers the D' peak by using its overtone the 2D'. We demonstrate the superiority and consistency of this method for calculating the oxygen content of graphenes, and use the relationship between the D' peak and graphene quality to define three regimes. This has important implications for purification techniques because, once GO is reduced beyond a critical threshold, further reduction offers limited gain in conductivity.
ABSTRACT
The reaction of nitric oxide (NO) and carbonaceous materials generates nitrogen functionalities on and in graphitic carbons and oxidizes some of the carbon. Here, we have exploited these phenomena to provide a novel route to surface-functionalized multiwalled carbon nanotubes (MWCNTs). We investigated the impacts of NO on the physical and chemical properties of industrially synthesized multiwalled carbon nanotubes to find a facile treatment that increased the specific surface area (SBET) of the MWCNTs by â¼20%, with only a minimal effect on their degree of graphitization. The technique caused less material loss (â¼12 wt %) than traditional gas-based activation techniques and grafted some nitrogen functional groups (1.1 at. %) on the MWCNTs. Moreover, we found that Ni nanoparticles deposited on NO-treated MWCNTs had a crystallite size of dNi = 13.1 nm, similar to those deposited on acid-treated MWCNTs (dNi = 14.2 nm), and clearly much smaller than those deposited under the same conditions on untreated MWCNTs (dNi = 18.3 nm).
ABSTRACT
Herein, boronic acid is incorporated into a graphene oxide (GO) structure in order to synthesise a graphene organic framework (GOF) with enhanced electrochemical performance. The results obtained indicate that the GOF favours a 4e(-) reduction pathway in the oxygen reduction reaction (ORR).
ABSTRACT
Herein, we report a solid-state reduction process (in contrast to solution-based approach) by using an environmentally friendly reductant, such as vitamin C (denoted VC), to be directly employed to solid-state graphene oxide (GO) templates to give the highly active rGO architecture with a sheet resistance of as low as 10 Ω sq(-1). In addition, predesigned rGO patterns/tracks with tunable resistivity can be directly "written" on a preprepared solid GO film via the inkjet-printing technique using VC/H2O as the printing-ink. This advanced reduction process allows foreign active materials to be preincorporated into the GO matrix to form quality active composite architectures.
Subject(s)
Ascorbic Acid/chemistry , Graphite/chemistry , Oxides/chemistry , Printing/methods , Water/chemistryABSTRACT
A series of Pt catalysts supported on Al2O3 that was doped with different amounts of CeO2 was developed, characterized, and tested in the aqueous-phase reforming (APR) of glycerol to H2. Catalyst 3Pt/3CeAl, which bore 3 wt% Pt on a support that contained 3â wt % CeO2, showed the highest carbon conversion to gas (85%) and the highest H2 yield (80%) for a feedstock of 1 wt% glycerol in water at 240 °C and 40 bar. A CeO2/Al2O3 support with only 1 wt% Pt also showed high H2 selectivity and carbon conversion to gas, as well as a much lower CH4 yield than the benchmark 3Pt/Al catalyst, clearly demonstrating that doping the support with 3 wt% CeO2 improved the APR of glycerol. H2 chemisorption results showed that the highest metal dispersion (58%) and active surface area (4.3 m(2)g(-1)) were achieved for the support that contained 3 wt% CeO2, and this effect appeared to be primarily responsible for the high H2 yield and carbon conversion to gas. No CO was observed in the product gas; therefore, this gas could potentially be used directly in proton exchange membrane fuel cells. Thus, including CeO2 in the Al2O3 catalyst support enhanced both the activity and selectivity towards H2 of a Pt catalyst for the APR of glycerol.
Subject(s)
Aluminum Oxide/chemistry , Cerium/chemistry , Glycerol/chemistry , Platinum/chemistry , Water/chemistry , Catalysis , Pressure , TemperatureABSTRACT
Aligned multiwalled carbon nanotube (CNT) arrays were prepared using chemical vapor deposition of C2H4 on Fe catalyst at 750 °C. CNT array height and alignment depends strongly on the duration of H2 pretreatment, with optimal height and alignment achieved using 10-15 min pretreatment. Small-angle X-ray scattering (SAXS) was used to quantify the alignment, distribution, and size of the CNTs in arrays produced from varying pretreatment times and the results correlated with microscopy measurements. SAXS analysis revealed that the higher section of the CNT arrays exhibited better alignment than the lower section. Combining these insights with transmission electron microscopy measurements of the CNT defects within each array enable a mechanism for the CNT growth to be proposed, where the loss of alignment arises from deformation of the CNTs during their growth. Gas permeation test across densified CNT arrays indicated that the alignment of the CNT array plays an important role in the gas transport, and that the gas diffusion across the well-aligned CNT arrays was enhanced by a factor of ~45, which is much more than that across the poorly aligned CNT arrays, with an enhancement factor of ~8.
ABSTRACT
Data on the bioavailability and toxicity of carbon nanotubes (CNTs) in the environment, and, in particular, on their interactions with vascular plants, are limited. We investigated the effects of industrial-grade multiwalled CNTs (75 wt% CNTs) and their impurities on alfalfa and wheat. Phytotoxicity assays were performed during both seed germination and seedling growth. The germinations of both species were tolerant of up to 2560 mg l(-1) CNTs, and root elongation was enhanced in alfalfa and wheat seedlings exposed to CNTs. Remarkably, catalyst impurities also enhanced root elongation in alfalfa seedlings as well as wheat germination. Thus the impurities, not solely the CNTs, impacted the plants. CNT internalization by plants was investigated using electron microscopy and two-dimensional Raman mapping. The latter showed that CNTs were adsorbed onto the root surfaces of alfalfa and wheat without significant uptake or translocation. Electron microscopy investigations of internalization were inconclusive owing to poor contrast, so Fe(3)O(4)-functionalized CNTs were prepared and studied using energy-filter mapping of Fe(3)O(4). CNTs bearing Fe(3)O(4) nanoparticles were detected in the epidermis of one wheat root tip only, suggesting that internalization was possible but unusual. Thus, alfalfa and wheat tolerated high concentrations of industrial-grade multiwalled CNTs, which adsorbed onto their roots but were rarely taken up.
Subject(s)
Medicago sativa/drug effects , Nanotubes, Carbon/toxicity , Triticum/drug effects , Adsorption , Germination/drug effects , Medicago sativa/metabolism , Nanotubes, Carbon/analysis , Plant Roots/drug effects , Plant Roots/metabolism , Plant Roots/ultrastructure , Seedlings/drug effects , Seedlings/growth & development , Spectrum Analysis, Raman , Triticum/metabolismABSTRACT
To exploit the promised benefits of engineered nanomaterials, it is necessary to improve our knowledge of their bioavailability and toxicity. The interactions between engineered nanomaterials and vascular plants are of particular concern, as plants closely interact with soil, water, and the atmosphere, and constitute one of the main routes of exposure for higher species, i.e. accumulation through the food chain. A review of the current literature shows contradictory evidence on the phytotoxicity of engineered nanomaterials. The mechanisms by which engineered nanomaterials penetrate plants are not well understood, and further research on their interactions with vascular plants is required to enable the field of phytotoxicology to keep pace with that of nanotechnology, the rapid evolution of which constantly produces new materials and applications that accelerate the environmental release of nanomaterials.
Subject(s)
Nanostructures/analysis , Nanostructures/toxicity , Plant Physiological Phenomena/drug effects , Plants/drug effects , Gene Expression Regulation, Plant/drug effects , Plant Development/drug effects , Plants/genetics , Plants/metabolismABSTRACT
The metal-organic framework Ni(2)(dobdc) (CPO-27-Ni, where dobdc = 1,4-dioxido-2,5-benzenedicarboxylate) has been post-synthetically modified with piperazine (pip) - a known 'accelerator' to improve the kinetics of CO(2) uptake in alkanolamine solvents for chemical absorption - and the impact of the modification on the CO(2) uptake and selectivity over N(2) has been probed. While the modified framework, Ni(2)(dobdc)(pip)(0.5) (pip-CPO-27-Ni), exhibits a lower uptake of CO(2) compared with the non-grafted material, the selectivity for CO(2) over N(2) at 25 °C and at pressures pertinent to post-combustion flue gas capture (0.1-0.15 bar) is enhanced. Mechanistically, the interaction between the CO(2) molecules and the free amine sites in pip-CPO-27-Ni occurs via physisorption and chemisorption interactions, in which CO(2) binds to the framework with an isosteric heat of adsorption (-Q(st)) of 40.5 kJ mol(-1) at very low coverage (P = 0.033 mbar), followed by binding at a higher heat of adsorption (-Q(st) = 46.2 kJ mol(-1) at P = 3.55 mbar). Pure water adsorption isotherms revealed a two-step mechanism for uptake in CPO-27-Ni, consistent with adsorption into the first and second hydration spheres of Ni(2+) followed by subsequent uptake via physisorption into the pores. Additional steric hindrance in pip-CPO-27-Ni results in a single step only. The working capacity over multiple cycles was also investigated using a temperature swing adsorption process which revealed reversible CO(2) adsorption and desorption of 10 wt% over 10 cycles.
ABSTRACT
A two-step floating-ferrocene chemical vapor deposition method has been devised for the preparation of single-layered aligned carbon nanotube (CNT) arrays. In the first step, uniform Fe catalysts are in situ produced and coated on a Si substrate from ferrocene; single-layered CNT arrays are prepared on these catalysts from ethylene in the second step. The effect of ferrocene loading on the distribution of Fe catalysts, as well as the morphology, diameter, and height of the CNT arrays, was investigated. A novel vacuum extraction process was employed to release the as-prepared CNT array from the Si wafer after water etching at 750 °C. The structural integrity of the free-standing arrays was preserved after the detachment process. The interface between the substrate and the as-grown CNT array was examined. The Fe catalyst distribution on the Si substrate remained homogeneous when the CNT array was removed, and the tops and bottoms of the arrays had different structures, suggesting that the arrays were formed predominantly by a base-growth mode. These free-standing arrays could potentially be applied in membrane or electronic applications.
ABSTRACT
Catalysis- and sorption-enhanced biomass gasification is a promising route to high-purity hydrogen (H(2)); however, most CaO-based sorbents for CO(2) capture have poor surface area and mechanical properties, lose carrying capacity over multiple uses, and have insufficient porosity to accommodate extra catalyst sites. We aimed to develop a high-surface-area CaO-SiO(2) framework onto which catalysts could be grafted. The best CaO-SiO(2) sorbent (n(Ca)/n(Si) = 2:1) maintained a CaO conversion of 65% even after 50 carbonation-decarbonation cycles, better than commercial micrometer-sized CaO or tailored CaO, because of stabilization via Ca-O-Si interactions and an ordered porous structure. Bimetallic catalyst grains (Ni/Co alloy, <20 nm) could be evenly loaded onto this structure by impregnation. The resulting bifunctional complex produced H(2) at nearly the same rate as a mixture of catalyst and commercial CaO while using less total sorbent/catalyst. Furthermore, this complex was much more durable due to its higher coking resistance and stable structure. After 25 carbonation-decarbonation cycles, the new catalyst-sorbent complex enhanced the H(2) yield from cellulose far more than a mixture of catalyst and commercial CaO did following the same treatment.
Subject(s)
Calcium Compounds/chemistry , Cellulose/metabolism , Cobalt/chemistry , Hydrogen/metabolism , Nickel/chemistry , Oxides/chemistry , Silicon Dioxide/chemistry , Adsorption , Biomass , Carbon Dioxide/chemistry , Cellulose/ultrastructure , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Nitrogen/chemistry , Temperature , X-Ray DiffractionABSTRACT
Polyhedral Fe/Al(2)O(3) catalysts prepared by an impregnation method were used for the synthesis of vertically aligned carbon nanotube (CNT) arrays from the pyrolysis of ethylene at 800 °C.