Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 117(36): 21968-21977, 2020 09 08.
Artículo en Inglés | MEDLINE | ID: mdl-32839342

RESUMEN

Biofuel and bioenergy systems are integral to most climate stabilization scenarios for displacement of transport sector fossil fuel use and for producing negative emissions via carbon capture and storage (CCS). However, the net greenhouse gas mitigation benefit of such pathways is controversial due to concerns around ecosystem carbon losses from land use change and foregone sequestration benefits from alternative land uses. Here, we couple bottom-up ecosystem simulation with models of cellulosic biofuel production and CCS in order to track ecosystem and supply chain carbon flows for current and future biofuel systems, with comparison to competing land-based biological mitigation schemes. Analyzing three contrasting US case study sites, we show that on land transitioning out of crops or pasture, switchgrass cultivation for cellulosic ethanol production has per-hectare mitigation potential comparable to reforestation and severalfold greater than grassland restoration. In contrast, harvesting and converting existing secondary forest at those sites incurs large initial carbon debt requiring long payback periods. We also highlight how plausible future improvements in energy crop yields and biorefining technology together with CCS would achieve mitigation potential 4 and 15 times greater than forest and grassland restoration, respectively. Finally, we show that recent estimates of induced land use change are small relative to the opportunities for improving system performance that we quantify here. While climate and other ecosystem service benefits cannot be taken for granted from cellulosic biofuel deployment, our scenarios illustrate how conventional and carbon-negative biofuel systems could make a near-term, robust, and distinctive contribution to the climate challenge.


Asunto(s)
Biocombustibles/análisis , Carbono/análisis , Gases de Efecto Invernadero/análisis , Biocombustibles/efectos adversos , Biotecnología , Carbono/metabolismo , Celulosa/química , Celulosa/metabolismo , Productos Agrícolas/química , Productos Agrícolas/metabolismo , Ecosistema , Etanol/metabolismo , Gases de Efecto Invernadero/efectos adversos
2.
Small ; 16(52): e2004133, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33251720

RESUMEN

Vasculopathy and the consequential ischemia are major medical challenges. Grafting is an effective treatment to vascular occlusion. However, autologous grafting, despite scarcity, is the only choice for small diameter blood vessels. Synthetic grafts can fill the gap if they can work satisfactorily in arterial circulation. Electrospun polycaprolactone (PCL) sheathed porous poly(glycerol sebacate) (PGS) vascular grafts have good performances in arterial circulation in abdominal aortas and carotid arteries in rats. However, a major issue associated with the graft remodeling in vivo is limited neo-tissue formation inside PCL sheaths. Small pores of PCL sheaths inhibit cell infiltration and migration. To increase porosity of PCL sheaths of PGS-PCL composite grafts, diameters of electrospun PCL fibers are increased. The thick PCL fibers encourage cell migration and elicit a higher degree of CD206+ cells. In addition, some of the CD206+ cells co-express vascular cell markers in the thick-fiber grafts. The thick-fiber grafts also show improved mechanical properties and a higher elastin and collagen content. The data demonstrate the feasibility of improving graft vascular remodeling by increasing PCL fiber diameters and the critical role of CD206+ cells during graft vascular remodeling.


Asunto(s)
Poliésteres , Injerto Vascular , Animales , Prótesis Vascular , Arteria Carótida Común , Elastina , Porosidad , Ratas , Ingeniería de Tejidos , Andamios del Tejido
3.
J Cutan Pathol ; 46(11): 839-843, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31322765

RESUMEN

BACKGROUND: Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a poorly understood but distinctive inflammatory hyperplasia occurring in children and young adults. Fewer than 100 cases have been reported since its initial description. METHODS: During the period of 2015 to 2018, cases of LJSGH were identified, retrieved and their clinical and histopathological data reviewed. RESULTS: There were 27 cases, with a median age of 13 years (range 7-72 years). Twenty-four of 27 patients were less than 20 years old, and in three cases the patients were over 60 years of age. The most commonly affected site was the anterior maxillary gingiva presenting as a solitary, red, and papillated lesion. Typical microscopic findings included elevated areas of variably acanthotic, spongiotic nonkeratinized epithelium with elongated rete ridges, accompanied by a neutrophilic-rich infiltrate. An abrupt transition between epithelium affected by LJSGH and normal mucosa was characteristic. LJSGH typically exhibited full-thickness epithelial expression of CK19 without expression of estrogen and progesterone receptors. CONCLUSIONS: The clinical and histopathologic characteristics of LJSGH are unique and consistent. Despite the name, the condition is not limited to juveniles and can occur in adults. LJSGH in adults and juveniles shares the same spectrum of histopathologic and immunohistochemical findings.


Asunto(s)
Encía , Hiperplasia Gingival , Mucosa Bucal , Adulto , Anciano , Niño , Femenino , Encía/metabolismo , Encía/patología , Hiperplasia Gingival/metabolismo , Hiperplasia Gingival/patología , Humanos , Masculino , Maxilar/metabolismo , Maxilar/fisiología , Persona de Mediana Edad , Mucosa Bucal/metabolismo , Mucosa Bucal/patología , Adulto Joven
4.
Neurosurg Focus ; 40(2): E10, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26828879

RESUMEN

Approximately half a million spinal fusion procedures are performed annually in the US. It is estimated that up to one-third of arthrodesis constructs require revision surgeries. In this study the authors present endoscopic treatment strategies targeting 3 types of complications following arthrodesis surgery: 1) adjacent-level foraminal stenosis; 2) foraminal stenosis at an arthrodesis segment; and 3) stenosis caused by a displaced interbody cage. A retrospective chart review of 11 patients with a mean age of 68 ± 15 years was performed (continuous variables are shown as the mean ± SEM). All patients had a history of lumbar arthrodesis surgery and suffered from unilateral radiculopathy. Endoscopic revision surgeries were done as outpatient procedures, and there were no intraoperative or perioperative complications. The cohort included 3 patients with foraminal stenosis at the level of previous arthrodesis. They presented with unilateral radicular leg pain (visual analog scale [VAS] score: 7.3 ± 2.1) and were severely disabled, as evidenced by an Oswestry Disability Index (ODI) of 46 ± 4.9. Transforaminal endoscopic foraminotomies were performed, and at a mean follow-up time of 9.0 ± 2.5 months VAS was reduced by an average of 6.3. The cohort also includes 7 patients suffering unilateral radiculopathy due to adjacent-level foraminal stenosis. Preoperative VAS for leg pain of the symptomatic side was 6.0 ± 1.6, VAS for back pain was 5.2 ± 1.7, and ODI was 40 ± 6.33. Endoscopic decompression led to reduction of the ipsilateral leg VAS score by an average of 5, resulting in leg pain of 1 ± 0.5 at an average of 8 months of follow-up. The severity of back pain remained stable (VAS 4.2 ± 1.4). Two of these patients required revision surgery for recurrent symptoms. Finally, this study includes 1 patient who presented with weakness and pain due to retropulsion of an L5/S1 interbody spacer. The patient underwent an endoscopic interlaminar approach with partial resection of the interbody cage, which resulted in complete resolution of her radicular symptoms. Endoscopic surgery may be a useful adjunct for management of certain arthrodesis-related complications. Endoscopic foraminal decompression of previously fused segments and resection of displaced interbody cages appears to have excellent outcomes, whereas decompression of adjacent segments remains challenging and requires further investigation.


Asunto(s)
Endoscopía/métodos , Complicaciones Posoperatorias/cirugía , Radiculopatía/cirugía , Fusión Vertebral/métodos , Estenosis Espinal/cirugía , Anciano , Anciano de 80 o más Años , Benzofenonas , Materiales Biocompatibles/uso terapéutico , Estudios de Cohortes , Evaluación de la Discapacidad , Femenino , Foraminotomía/métodos , Lateralidad Funcional , Humanos , Cetonas/uso terapéutico , Vértebras Lumbares/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Polietilenglicoles/uso terapéutico , Polímeros , Estenosis Espinal/etiología , Tomógrafos Computarizados por Rayos X , Escala Visual Analógica
5.
Br J Haematol ; 171(4): 509-16, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26260306

RESUMEN

A phase II study was performed to evaluate the efficacy of hyper-fractionated cyclophosphamide, vincristine, pegylated liposomal doxorubicin and dexamethasone alternating with methotrexate/cytarabine (HCVIDD/MA) in patients with newly diagnosed peripheral T-cell lymphoma (PTCL), excluding ALK-positive anaplastic large cell lymphoma. Fifty-three patients were enrolled. Treatment was planned for up to 8 cycles but only 9% of patients received more than 6 cycles due primarily to disease progression (n = 13) or prolonged thrombocytopenia (n = 12). The overall response rate was 66% with a complete response rate of 57%. Median progression-free survival (PFS) was 7·5 months. With a median follow-up of 7·6 years, 5-year PFS and overall survival (OS) were 21% and 48%, respectively. The patients with extranodal Natural Killer-cell lymphoma had a shorter PFS (median, 2·4 months) than other subtypes. Grade 3/4 anaemia, neutropenia and thrombocytopenia were observed in 66%, 74% and 79% of patients, respectively. Of note, 23% of patients discontinued therapy due to prolonged thrombocytopenia. In conclusion, HCVIDD/MA for the first-line treatment of PTCL patients is associated with significant myelosuppression leading to poor treatment adherence, and the response and survival outcomes with this regimen are similar to standard CHOP. This study was registered at www.clinicaltrials.gov as #NCT00290433.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Linfoma de Células T Periférico/tratamiento farmacológico , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Enfermedades de la Médula Ósea/inducido químicamente , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Citarabina/administración & dosificación , Citarabina/efectos adversos , Dexametasona/administración & dosificación , Dexametasona/efectos adversos , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Doxorrubicina/análogos & derivados , Esquema de Medicación , Femenino , Humanos , Estimación de Kaplan-Meier , Linfoma Extranodal de Células NK-T/tratamiento farmacológico , Masculino , Cumplimiento de la Medicación , Metotrexato/administración & dosificación , Metotrexato/efectos adversos , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , Polietilenglicoles/efectos adversos , Inducción de Remisión , Resultado del Tratamiento , Vincristina/administración & dosificación , Vincristina/efectos adversos , Adulto Joven
6.
Nanotechnology ; 26(5): 055601, 2015 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-25573923

RESUMEN

Functional colloidal materials were prepared by design through the self-assembly of nanoparticles (NPs) on the surfaces of polystyrene (PS) spheres with control over NP surface coverage, NP-to-NP spacing, and NP composition. The ability to control and fine tune the coating was extended to the first demonstration of the co-assembly of NPs of dissimilar composition onto the same PS sphere, forming a multi-component coating. A broad range of NP decorated PS (PS@NPs) spheres were prepared with uniform coatings attributed to electrostatic and hydrogen bonding interactions between stabilizing groups on the NPs and the functionalized surfaces of the PS spheres. This versatile two-step method provides more fine control than methods previously demonstrated in the literature. These decorated PS spheres are of interest for a number of applications, such as catalytic reactions where the PS spheres provide a support for the dispersion, stabilization, and recovery of NP catalysts. The catalytic properties of these PS@NPs spheres were assessed by studying the catalytic degradation of azo dyes, an environmental contaminant detrimental to eye health. The PS@NPs spheres were used in multiple, sequential catalytic reactions while largely retaining the NP coating.


Asunto(s)
Nanopartículas/química , Poliestirenos , Compuestos Azo/metabolismo , Catálisis , Nanotecnología
7.
Dev Dyn ; 243(11): 1470-6, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25073978

RESUMEN

BACKGROUND: Eph receptors, comprising the A- and B-subfamilies, are the largest family of receptor tyrosine kinases in the mammalian genome, and their function is critical for morphogenesis in a variety of contexts. Whereas signaling through B-type Ephs has been demonstrated to play a role in cleft lip and palate (CL/P), the involvement of A-type Ephs has not been examined in this context notwithstanding a recent genome-wide association study that identified the EPHA3 locus as a candidate for non-syndromic CL/P. RESULTS: Here, we present a systematic analysis of the gene expression patterns for the nine EphA receptors at progressive stages of mouse development and find that EphA3, EphA4, and EphA7 exhibit restricted overlapping patterns of expression during palate development. We find that homozygous mutation of EphA3 or compound homozygous mutation of EphA3 and EphA4 in mice does not result in defective midfacial development, supporting the possibility of redundant function with EphA7. We also document previously undescribed expression patterns in other tissues of the craniofacial complex including the lacrimal duct and salivary glands. CONCLUSIONS: Together, these results are consistent with the hypothesis that mutations in EPHA family genes may cause CL/P and also suggest that functional redundancy between family members may be at play.


Asunto(s)
Labio Leporino/genética , Fisura del Paladar/genética , Regulación del Desarrollo de la Expresión Génica/fisiología , Morfogénesis/fisiología , Hueso Paladar/embriología , Receptores de la Familia Eph/metabolismo , Animales , Perfilación de la Expresión Génica , Técnicas Histológicas , Ratones , Ratones Noqueados
8.
Proc Natl Acad Sci U S A ; 108(51): 20400-3, 2011 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-22123978

RESUMEN

This manuscript describes a unique class of locomotive robot: A soft robot, composed exclusively of soft materials (elastomeric polymers), which is inspired by animals (e.g., squid, starfish, worms) that do not have hard internal skeletons. Soft lithography was used to fabricate a pneumatically actuated robot capable of sophisticated locomotion (e.g., fluid movement of limbs and multiple gaits). This robot is quadrupedal; it uses no sensors, only five actuators, and a simple pneumatic valving system that operates at low pressures (< 10 psi). A combination of crawling and undulation gaits allowed this robot to navigate a difficult obstacle. This demonstration illustrates an advantage of soft robotics: They are systems in which simple types of actuation produce complex motion.


Asunto(s)
Marcha , Animales , Biomimética , Decapodiformes , Diseño de Equipo , Humanos , Movimiento , Polímeros/química , Presión , Robótica , Grabación en Video
9.
Spine J ; 24(10): 1890-1899, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38843956

RESUMEN

BACKGROUND CONTEXT: Perioperative pain management affects cost and outcomes in elective spine surgery. PURPOSE: This study investigated the association between liposomal bupivacaine (LB) and outpatient spine surgery outcomes, including perioperative, postoperative, and postdischarge opioid use and healthcare resource utilization. STUDY DESIGN: This was a retrospective comparative study. PATIENT SAMPLE: Eligibility criteria included adults with ≥6 months of continuous data before and after outpatient spine procedures including discectomy, laminectomy, or lumbar fusion. Patients receiving LB were matched 1:3 to patients receiving non-LB analgesia by propensity scores. OUTCOME MEASURES: Outcomes included (1) opioid use in morphine milligram equivalents (MMEs) during the perioperative and postdischarge periods and (2) postdischarge readmission and emergency department (ED) visits up to 3 months after surgery. Generalized linear mixed-effects modeling with appropriate distributions was used for analysis. METHODS: Deidentified data from the IQVIA linkage claims databases (2016-2019) were used for the analysis. This study was funded by Pacira BioSciences, Inc. RESULTS: In total, 381 patients received LB and 1143 patients received non-LB analgesia. Baseline characteristics were well balanced after propensity score matching. The LB cohort used fewer MMEs versus the non-LB cohort before discharge (80 vs 132 MMEs [mean difference, -52 MMEs; p=.0041]). Following discharge, there was a nonsignificant reduction in opioid use in the LB cohort versus the non-LB cohort within 90 days (429 vs 480 MMEs [mean difference, -50 MMEs; p=.289]) and from >90 days to 180 days (349 vs 381 MMEs [mean difference, -31 MMEs; p=.507]). The LB cohort had significantly lower rates of ED visits at 2 months after discharge versus the non-LB cohort (3.9% vs 7.6% [odds ratio, 0.50; p=.015]). Postdischarge readmission rates did not differ between cohorts. CONCLUSIONS: Use of LB for outpatient spine surgery was associated with reduced opioid use at the hospital and nonsignificant reduction in opioid use at all postoperative timepoints examined through 90 days after surgery versus non-LB analgesia. ED visit rates were significantly lower at 60 days after discharge. These findings support reduced cost and improved quality metrics in patients treated with LB versus non-LB analgesia for outpatient spine surgery.


Asunto(s)
Procedimientos Quirúrgicos Ambulatorios , Analgésicos Opioides , Anestésicos Locales , Bupivacaína , Liposomas , Dolor Postoperatorio , Humanos , Femenino , Masculino , Bupivacaína/administración & dosificación , Bupivacaína/uso terapéutico , Persona de Mediana Edad , Analgésicos Opioides/uso terapéutico , Analgésicos Opioides/administración & dosificación , Estudios Retrospectivos , Dolor Postoperatorio/tratamiento farmacológico , Adulto , Anestésicos Locales/administración & dosificación , Anestésicos Locales/uso terapéutico , Anciano , Aceptación de la Atención de Salud/estadística & datos numéricos , Readmisión del Paciente/estadística & datos numéricos , Manejo del Dolor/métodos , Manejo del Dolor/estadística & datos numéricos , Columna Vertebral/cirugía
10.
Anal Chem ; 85(20): 9960-7, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-24016255

RESUMEN

A quantitative and tunable loading of single-stranded (ss-DNA) molecules onto gold nanorods was achieved through a new method of surfactant exchange. This new method involves the exchange of cetyltrimethylammonium bromide surfactants for an intermediate stabilizing layer of polyvinylpyrrolidone and sodium dodecylsulfate. The intermediate layer of surfactants on the anisotropic gold particles was easily displaced by thiolated ss-DNA, forming a tunable density of single-stranded DNA molecules on the surfaces of the gold nanorods. The success of this ligand exchange process was monitored in part through the combination of extinction, X-ray photoelectron, and infrared absorption spectroscopies. The number of ss-DNA molecules per nanorod for nanorods with a high density of ss-DNA molecules was quantified through a combination of fluorescence measurements and elemental analysis, and the functionality of the nanorods capped with dense monolayers of DNA was assessed using a hybridization assay. Core-satellite assemblies were successfully prepared from spherical particles containing a probe DNA molecule and a nanorod core capped with complementary ss-DNA molecules. The methods demonstrated herein for quantitatively fine tuning and maximizing, or otherwise optimizing, the loading of ss-DNA in monolayers on gold nanorods could be a useful methodology for decorating gold nanoparticles with multiple types of biofunctional molecules.


Asunto(s)
ADN de Cadena Simple/química , Oro/química , Nanotubos/química , Povidona/química , Concentración de Iones de Hidrógeno , Dodecil Sulfato de Sodio/química , Propiedades de Superficie , Tensoactivos/química
11.
World Neurosurg ; 173: 13-22, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36716852

RESUMEN

INTRODUCTION: Metastatic spine tumors affect over 30% of patients who have been diagnosed with cancer. While techniques in surgical intervention have undoubtedly evolved, there are some pitfalls when spinal instrumentation is required for stabilization following tumor resection. However, the use of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implants has become increasingly popular due to improved radiolucency and positive osteobiologic properties. Here, we present a systematic review describing the use of CFR-PEEK-coated instrumentation in the oncologic population while identifying advantages and potential shortcomings of these devices. METHODS: In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, a systematic review was conducted in March 2022 to identify articles detailing the use of CFR-PEEK implants for spinal instrumentation in patients with primary and secondary spine tumors. The search was performed using the PubMed, Scopus, and Embase databases. RESULTS: An initial search returned a total of 85 articles among the three databases used. After the exclusion of duplicates and screening of abstracts, 21 full-text articles were examined for eligibility. Eleven articles were excluded due to not fitting our inclusion and exclusion criteria. Ten articles were subsequently eligible for full-text review. CONCLUSIONS: CFR-PEEK possesses a similar safety and efficacy profile to titanium implants but has distinct advantages. It limits artifact, increases early detection of local tumor recurrence, increases radiotherapy dose accuracy, and is associated with low complication rates (9.96%)-making it a promising alternative for the demands unique to the treatment/outcome of spinal oncologic patients.


Asunto(s)
Neoplasias del Sistema Nervioso Central , Neoplasias de la Médula Espinal , Neoplasias de la Columna Vertebral , Humanos , Fibra de Carbono , Polímeros , Benzofenonas , Polietilenglicoles , Cetonas , Neoplasias de la Columna Vertebral/cirugía , Carbono
12.
J Pharm Sci ; 112(8): 2057-2068, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36574837

RESUMEN

Co-precipitation is an emerging manufacturing strategy for amorphous solid dispersions (ASDs). Herein, the interplay between processing conditions, surface composition, and release performance was evaluated using grazoprevir and hypromellose acetate succinate as the model drug and polymer, respectively. Co-precipitated amorphous dispersion (cPAD) particles were produced in the presence and absence of an additional polymer that was either dissolved or dispersed in the anti-solvent. This additional polymer in the anti-solvent was deposited on the surfaces of the cPAD particles during isolation and drying to create hierarchical particles, which we define here as a core ASD particle with an additional water soluble component that is coating the particle surfaces. The resultant hierarchical particles were characterized using X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, and X-ray photoelectron spectroscopy (XPS). Release performance was evaluated using a two-stage dissolution test. XPS analysis revealed a trend whereby cPAD particles with a lower surface drug concentration showed improved release relative to particles with a higher surface drug concentration, for nominally similar drug loadings. This surface drug concentration could be impacted by whether the secondary polymer was dissolved in the anti-solvent or dispersed in the anti-solvent prior to isolating final dried hierarchical cPAD powders. Grazoprevir exposure in dogs was higher when the hierarchical cPAD was dosed, with ∼1.8 fold increase in AUC compared to the binary cPAD. These observations highlight the important interplay between processing conditions and ASD performance in the context of cPAD particles and illustrate a hierarchical particle design as a successful approach to alter ASD surface chemistry to improve dissolution performance.


Asunto(s)
Ciclopropanos , Polímeros , Animales , Perros , Solubilidad , Composición de Medicamentos/métodos , Polímeros/química , Solventes , Liberación de Fármacos
13.
Langmuir ; 28(29): 10838-48, 2012 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-22738388

RESUMEN

We investigate the surface-directed phase separation of spin-coated polystyrene/poly(methyl methacrylate) (PS/PMMA) blends on prepatterned octadecyltrichlorosilane (OTS)-glass substrates under various experimental conditions. As a result of tandem processes of spinodal decomposition and selective wetting of polymer components during spin-coating, low-energy OTS stripes and high-energy glass surfaces laterally arrange the phase-separated polymers according to the chemical pattern on the substrate. Optimal pattern replication was achieved when the length scale of phase separation, controlled via the polymer concentration of the spin-coating solution, matched the smallest feature dimension in a striped chemical pattern possessing two alternating distances between stripes. It was also shown that polymer blend patterns were most closely registered with the underlying substrate when the PS/PMMA composition ratio (30/70, w/w) matched the areal fraction of OTS on the glass surface (∼30%). The influence of solvents demonstrated that a solvent with a relatively low volatility, such toluene, was required for patterning so that domain feature sizes were able to coarsen to the size of the patterned features before film vitrification. As well, we showed that the technique and optimized conditions developed in this study could be applied to pattern photoluminescent CdS quantum dots into microscale arrays of parallel lines via spin-coating onto transparent OTS-glass substrates.


Asunto(s)
Nanopartículas/química , Polimetil Metacrilato/química , Poliestirenos/química , Tamaño de la Partícula , Silanos/química , Propiedades de Superficie
14.
J Thromb Thrombolysis ; 34(1): 91-8, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22350685

RESUMEN

We previously found paclitaxel-eluting polymer-coated stents causing more human platelet-monocyte complex formation than bare metal stents in vitro. Presently, we examined patterns of platelet activation and adhesion after exposure to 6 nanofilm HAp-coated (HAp-nano) stents, 6 HAp-microporous-coated (HAp-micro) stents, 5 HAp sirolimus-eluting microporous-coated (HAp-SES) stents and 5 cobalt-chromium stents (BMS) deployed in an in vitro flow system. Blood obtained from healthy volunteers was circulated and sampled at 0, 10, 30 and 60 min. By flow cytometry, there were no significant differences in P-Selectin expression between the 4 stent types (HAp-nano = 32.5%; HAp-micro = 42.5%, HAp-SES = 10.23%, BMS = 7% change from baseline at 60 min, p = NS); PAC-1 antibody binding (HAp-nano = 11.8%; HAp-micro = 2.9%, HAp-SES = 18%, BMS = 6.4% change from baseline at 60 min, p = NS) or PMC formation (HAp-nano = 21.6%; HAp-micro = 4%, HAp-SES = 6.6%, BMS = 17.4% change from baseline at 60 min, p = NS). The 4 stent types did not differ in the average number of platelet clusters >10 µm in diameter by SEM (HAp-nano = 2.39 ± 5.75; HAp-micro = 2.26 ± 3.43; HAp-SES = 1.93 ± 3.24; BMS = 1.94 ± 2.41, p = NS). The majority of the struts in each stent group were only mildly covered by platelets, (HAp-nano = 80%, HAp-micro = 61%, HAp-SES = 78% and BMS = 52.1%, p = NS). The HAp-microporous-coated stents (ECD) attracted slightly more proteinaceous material than bare metal stents (HAp-micro = 35% struts with complete protein coverage, P < 0.0001 vs. other 3 stent types). In conclusion, biomimetic stent coating with nanofilm or microporous hydroxyapatite, even when eluting low-dose sirolimus, does not increase the platelet activation in circulating human blood, or platelet adhesion to stent surface when compared to bare metal stents in vitro.


Asunto(s)
Materiales Biocompatibles Revestidos , Stents Liberadores de Fármacos , Durapatita , Inmunosupresores/farmacología , Ensayo de Materiales , Activación Plaquetaria/efectos de los fármacos , Sirolimus/farmacología , Adulto , Femenino , Humanos , Masculino , Factores de Tiempo
15.
Biotechnol Lett ; 34(12): 2259-63, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23086569

RESUMEN

Enzymes and yeast are important ingredients in the production of ethanol, yet the energy consumption and emissions associated with their production are often excluded from life-cycle analyses of ethanol. We provide new estimates for the energy consumed and greenhouse gases (GHGs) emitted during enzyme and yeast manufacture, including contributions from key ingredients such as starch, glucose, and molasses. We incorporated these data into Argonne National Laboratory's Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model and observed that enzymes and yeast together contribute 1.4 and 27 % of farm-to-pump GHG emissions for corn and cellulosic ethanol, respectively. Over the course of the entire corn ethanol life cycle, yeast and enzymes contribute a negligible amount of GHG emissions, but increase GHG emissions from the cellulosic ethanol life cycle by 5.6 g CO(2)e/MJ.


Asunto(s)
Dióxido de Carbono/metabolismo , Celulosa/metabolismo , Etanol/metabolismo , Levaduras/enzimología , Levaduras/metabolismo , Zea mays/metabolismo , Metabolismo Energético , Glucosa/metabolismo , Melaza , Almidón/metabolismo
16.
Environ Sci Technol ; 45(7): 3047-53, 2011 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-21370852

RESUMEN

This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.


Asunto(s)
Contaminantes Atmosféricos/análisis , Huella de Carbono/estadística & datos numéricos , Conservación de los Recursos Energéticos/métodos , Gasolina/análisis , Centrales Eléctricas/estadística & datos numéricos , Contaminación del Aire/estadística & datos numéricos , Biomasa , Celulosa , Carbón Mineral
17.
Proc Natl Acad Sci U S A ; 105(40): 15287-92, 2008 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-18772377

RESUMEN

Egress of lipoprotein-derived cholesterol from lysosomes requires two lysosomal proteins, polytopic membrane-bound Niemann-Pick C1 (NPC1) and soluble Niemann-Pick C2 (NPC2). The reason for this dual requirement is unknown. Previously, we showed that the soluble luminal N-terminal domain (NTD) of NPC1 (amino acids 25-264) binds cholesterol. This NTD is designated NPC1(NTD). We and others showed that soluble NPC2 also binds cholesterol. Here, we establish an in vitro assay to measure transfer of [(3)H]cholesterol between these two proteins and phosphatidylcholine liposomes. Whereas NPC2 rapidly donates or accepts cholesterol from liposomes, NPC1(NTD) acts much more slowly. Bidirectional transfer of cholesterol between NPC1(NTD) and liposomes is accelerated >100-fold by NPC2. A naturally occurring human mutant of NPC2 (Pro120Ser) fails to bind cholesterol and fails to stimulate cholesterol transfer from NPC1(NTD) to liposomes. NPC2 may be essential to deliver or remove cholesterol from NPC1, an interaction that links both proteins to the cholesterol egress process from lysosomes. These findings may explain how mutations in either protein can produce a similar clinical phenotype.


Asunto(s)
Proteínas Portadoras/metabolismo , Colesterol/metabolismo , Glicoproteínas/metabolismo , Membrana Dobles de Lípidos/metabolismo , Lipoproteínas/metabolismo , Lisosomas/metabolismo , Glicoproteínas de Membrana/metabolismo , Endosomas/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular , Cinética , Liposomas/metabolismo , Modelos Biológicos , Proteína Niemann-Pick C1 , Enfermedades de Niemann-Pick/metabolismo , Proteínas de Transporte Vesicular
18.
Water Environ Res ; 93(2): 186-200, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32609913

RESUMEN

The mechanisms of plastic transport in rivers remain an important knowledge gap in global plastic pollution research and management. We investigated how river flows and plastics' properties affect transport with a five-point cross-sectional field study in the Hillsborough River in Tampa (Florida, USA) using a 500-µm Neuston net and an Acoustic Doppler Current Profiler. We conducted in-depth analysis of water velocity profiles as well as plastics' concentrations and properties, determining advective, vertical, and lateral transport fluxes. Under calm flow conditions, advective fluxes were two orders of magnitude higher than lateral and vertical fluxes. Under turbulent conditions, enhanced particle exchange in the cross-section resulted in a three to tenfold increase in lateral and vertical plastic fluxes. The impact of turbulence on plastic particles depended on properties such as size, shape, and composition. This study presents a unique assessment of flow conditions driving plastic pollution in an urban coastal river setting. PRACTITIONERS POINTS: Multipoint, cross-sectional sampling and onsite flow profile collection should be adopted as a common practice for plastic field data collection to reduce uncertainty. Varying flow conditions affect the drivers of plastic transport in rivers. Advective surface fluxes govern plastic transport under calm flow conditions, while turbulent flow conditions enhance cross-sectional mixing and particle exchange. Larger and more irregular-shaped plastics are more affected by turbulence.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , Estudios Transversales , Monitoreo del Ambiente , Florida , Hidrodinámica , Ríos , Contaminantes Químicos del Agua/análisis
19.
N Z Med J ; 134(1545): 106-119, 2021 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-34788276

RESUMEN

AIM: Patients with incurable oesophageal cancer have poor outcomes, with disabling symptoms and a poor quality of life (QOL), which may be improved by oesophageal stenting. We aimed to measure change in symptoms related specifically to oesophageal cancer and overall QOL before and 30 days after stent insertion, to measure adverse effects and to define any patient factors that may be significant in predicting patients who may benefit most. METHODS: We prospectively enrolled patients in an observational study at Middlemore Hospital, New Zealand, and administered validated QOL- and symptomatology-based questionnaires before and 30 days after stent insertion. Additional patient-related demographics, procedural characteristics, adverse events and outcomes were collected. RESULTS: Between 31 March 2014 and 3 July 2020, 57 patients were initially recruited. Four patients withdrew from the study, and 13 patients died before 30 days. Forty patients (29 males; mean±SD age, 72±12 years) completed the study. A significant improvement was noted at one-month post stent insertion in the overall global QOL score (mean 35 to 46, p=0.01). The most significant score improvements were seen in dysphagia, trouble eating, trouble swallowing saliva and dry mouth (p<0.001). Physical, emotional, cognitive and social functioning did not change. Post-procedural adverse events occurred in 17 patients (43%). A poorer initial level of functioning was associated with reduced improvement in global QOL (p≤0.04). Patients followed-up died a mean of 2.8 months after insertion. CONCLUSION: In patients surviving longer than 30 days, there is significant improvement of overall QOL and dysphagia one-month post oesophageal stent insertion for malignant, palliative dysphagia. Multiple psychosocial facets were unchanged with this intervention. Stent-related adverse events were common.


Asunto(s)
Trastornos de Deglución/terapia , Neoplasias Esofágicas/terapia , Cuidados Paliativos , Calidad de Vida , Stents , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda , Estudios Prospectivos , Encuestas y Cuestionarios
20.
Cont Lens Anterior Eye ; 43(2): 99-102, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31542280

RESUMEN

PURPOSE: To explore the association between xerostomia and dry eye symptoms in the older adult population. METHODS: Secondary analysis of data from 627 participants (346 male, 291 female), with a mean ±â€¯SD age of 75 ±â€¯7 years, recruited through the population-based South Australian Dental Longitudinal Study. Participants completed the validated Summated Xerostomia Inventory-Dutch Version questionnaire (SXI-D), and rated their overall frequency of dry eye symptoms at baseline. RESULTS: Symptomatic dry eye was reported by 31% of participants, and xerostomia by 21%. A positive correlation was observed between dry eye symptoms and SXI-D scores (Spearman's rho = +0.379, p < 0.001). Overall, participants with symptomatic dry eye had higher SXI-D scores than those without (10.6 ±â€¯3.6 vs. 8.1 ±â€¯2.8, p < 0.001), and were more likely to report xerostomia, with an odds ratio (95% CI) of 2.25 (1.52-3.35; p < 0.001). CONCLUSIONS: Symptoms of xerostomia and dry eye were relatively common in the cohort of older adult participants. The potentially debilitating implications of - and positive association between - the two types of sicca symptoms support the routine evaluation of xerostomia symptoms as part of the assessment of dry eye patients, and vice versa.


Asunto(s)
Síndromes de Ojo Seco/etiología , Vigilancia de la Población , Xerostomía/complicaciones , Factores de Edad , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Síndromes de Ojo Seco/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Xerostomía/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA