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1.
Sci Rep ; 14(1): 1928, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38253799

RESUMEN

High-quality epitaxial p-type V2O3 thin films have been synthesized by spray pyrolysis. The films exhibited excellent electrical performance, with measurable mobility and high carrier concentration. The conductivity of the films varied between 115 and 1079 Scm-1 while the optical transparency of the films ranged from 32 to 65% in the visible region. The observed limitations in thinner films' mobility were attributed to the nanosized granular structure and the presence of two preferred growth orientations. The 60 nm thick V2O3 film demonstrated a highly competitive transparency-conductivity figure of merit compared to the state-of-the-art.

2.
Cancer ; 129(5): 780-789, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36571557

RESUMEN

BACKGROUND: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorder [EBV(-)M-PTLD] comprises approximately 10% of M-PTLD. No large multi-institutional pediatric-specific reports on treatment and outcome are available. METHODS: A multi-institutional retrospective review of solid organ recipients diagnosed with EBV(-)M-PTLD aged ≤21 years between 2001 and 2020 in 12 centers in the United States and United Kingdom was performed, including demographics, staging, treatment, and outcomes data. RESULTS: Thirty-six patients were identified with EBV(-)M-PTLD. Twenty-three (63.9%) were male. Median age (range) at transplantation, diagnosis of EBV(-)M-PTLD, and interval from transplant to PTLD were 2.2 years (0.1-17), 14 years (3.0-20), and 8.5 years (0.6-18.3), respectively. Kidney (n = 17 [47.2%]) and heart (n = 13 [36.1%]) were the most commonly transplanted organs. Most were Murphy stage III (n = 25 [69.4%]). Lactate dehydrogenase was elevated in 22/34 (64.7%) and ≥2 times upper limit of normal in 11/34 (32.4%). Pathological diagnoses included diffuse large B-cell lymphoma (n = 31 [86.1%]) and B-non-Hodgkin lymphoma (B-NHL) not otherwise specified (NOS) (n = 5 [13.9%]). Of nine different regimens used, the most common were: pediatric mature B-NHL-specific regimen (n = 13 [36.1%]) and low-dose cyclophosphamide, prednisone, and rituximab (n = 9 [25%]). Median follow-up from diagnosis was 3.0 years (0.3-11.0 years). Three-year event-free survival (EFS) and overall survival (OS) were 64.8% and 79.9%, respectively. Of the seven deaths, six were from progressive disease. CONCLUSIONS: EFS and OS were comparable to pediatric EBV(+) PTLD, but inferior to mature B-NHL in immunocompetent pediatric patients. The wide range of therapeutic regimens used directs our work toward developing an active multi-institutional registry to design prospective studies. PLAIN LANGUAGE SUMMARY: Pediatric Epstein-Barr virus-negative monomorphic post solid organ transplant lymphoproliferative disorders (EBV(-)M-PTLD) have comparable outcomes to EBV(+) PTLD, but are inferior to diffuse large B-cell lymphoma in immunocompetent pediatric patients. The variety of treatment regimens used highlights the need to develop a pediatric PTLD registry to prospectively evaluate outcomes. The impact of treatment regimen on relapse risk could not be assessed because of small numbers. In the intensive pediatric B-non-Hodgkin lymphoma chemoimmunotherapy group, 11 of 13 patients remain alive in complete remission after 0.6 to 11 years.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Linfoma de Células B Grandes Difuso , Linfoma no Hodgkin , Trastornos Linfoproliferativos , Trastornos Mieloproliferativos , Trasplante de Órganos , Niño , Humanos , Masculino , Femenino , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/epidemiología , Herpesvirus Humano 4 , Estudios Prospectivos , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/etiología , Linfoma no Hodgkin/complicaciones , Linfoma de Células B Grandes Difuso/patología , Trastornos Mieloproliferativos/complicaciones , Estudios Retrospectivos , Trasplante de Órganos/efectos adversos
3.
Br J Haematol ; 200(3): 297-305, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36454546

RESUMEN

Burkitt lymphoma arising in paediatric post-solid-organ transplantation-Burkitt lymphoma (PSOT-BL) is a clinically aggressive malignancy and a rare form of post-transplant lymphoproliferative disorder (PTLD). We evaluated 35 patients diagnosed with PSOT-BL at 14 paediatric medical centres in the United States. Median age at organ transplantation was 2.0 years (range: 0.1-14) and age at PSOT-BL diagnosis was 8.0 years (range: 1-17). All but one patient had late onset of PSOT-BL (≥2 years post-transplant), with a median interval from transplant to PSOT-BL diagnosis of 4.0 years (range: 0.4-12). Heart (n = 18 [51.4%]) and liver (n = 13 [37.1%]) were the most frequently transplanted organs. No patients had loss of graft or treatment-related mortality. A variety of treatment regimens were used, led by intensive Burkitt lymphoma-specific French-American-British/Lymphomes Malins B (FAB/LMB), n = 13 (37.1%), and a low-intensity regimen consisting of cyclophosphamide, prednisone and rituximab (CPR) n = 12 (34.3%). Median follow-up was 6.7 years (range: 0.5-17). Three-year event-free and overall survival were 66.2% and 88.0%, respectively. Outcomes of PSOT-BL patients receiving BL-specific intensive regimens are comparable to reported BL outcomes in immunocompetent children. Multi-institutional collaboration is feasible and provides the basis of prospective data collection to determine the optimal treatment regimen for PSOT-BL.


Asunto(s)
Linfoma de Burkitt , Trastornos Linfoproliferativos , Trasplante de Órganos , Humanos , Niño , Lactante , Preescolar , Adolescente , Linfoma de Burkitt/terapia , Linfoma de Burkitt/tratamiento farmacológico , Trasplante de Órganos/efectos adversos , Ciclofosfamida/uso terapéutico , Rituximab/uso terapéutico , Prednisona/uso terapéutico , Trastornos Linfoproliferativos/etiología , Resultado del Tratamiento , Estudios Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos
4.
Microbiologyopen ; 11(1): e1264, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35212475

RESUMEN

Adaptation of opportunistic pathogens to their host environment requires reprogramming of a vast array of genes to facilitate survival in the host. Burkholderia cenocepacia, a Gram-negative bacterium with a large genome of ∼8 Mb that colonizes environmental niches, is exquisitely adaptable to the hypoxic environment of the cystic fibrosis lung and survives in macrophages. We previously identified an immunoreactive acidic protein encoded on replicon 3, BCAS0292. Deletion of the BCAS0292 gene significantly altered the abundance of 979 proteins by 1.5-fold or more; 19 proteins became undetectable while 545 proteins showed ≥1.5-fold reduced abundance, suggesting the BCAS0292 protein is a global regulator. Moreover, the ∆BCAS0292 mutant showed a range of pleiotropic effects: virulence and host-cell attachment were reduced, antibiotic susceptibility was altered, and biofilm formation enhanced. Its growth and survival were impaired in 6% oxygen. In silico prediction of its three-dimensional structure revealed BCAS0292 presents a dimeric ß-structure with a negative surface charge. The ΔBCAS0292 mutant displayed altered DNA supercoiling, implicated in global regulation of gene expression. Three proteins were identified in pull-downs with FLAG-tagged BCAS0292, including the Histone H1-like protein, HctB, which is recognized as a global transcriptional regulator. We propose that BCAS0292 protein, which we have named Burkholderia negatively surface-charged regulatory protein 1 (Bnr1), acts as a DNA-mimic and binds to DNA-binding proteins, altering DNA topology and regulating the expression of multiple genes, thereby enabling the adaptation of B. cenocepacia to highly diverse environments.


Asunto(s)
Adaptación Fisiológica/fisiología , Proteínas Bacterianas/fisiología , Burkholderia cenocepacia/fisiología , ADN Bacteriano/fisiología , Imitación Molecular/fisiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/patogenicidad , ADN Bacteriano/genética , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación Bacteriana de la Expresión Génica , Familia de Multigenes/genética , Virulencia
5.
Opt Express ; 29(10): 15031-15052, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33985212

RESUMEN

Hybrid 3D Finite difference time domain-Monte Carlo ray tracing (FDTD-MCRT) algorithm has been developed to model and optimise small and large scale plasmonically-enhanced luminescent solar concentrator (pLSC) devices for photovoltaic (PV) applications. The configuration parameters (for example, dimensions, shape, and optical properties of metal nanoparticles, luminescent species, and host material) were used to characterise the probability of optical energy transfer and loss processes, as well as reflection, refraction, absorption, emission enhancement, and total internal reflection (TIR) in the pLSC. The algorithm was validated through modelling of various doping concentrations of CdSe/ZnS quantum dots (QD) and gold nano spheres (Au NS) where ∼50% enhancement in optical conversion efficiency (OCE) was observed for a plasmonic composite of 2 ppm Au NS and 0.008 wt. % QD.

6.
Opt Express ; 28(14): 20191-20204, 2020 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-32680084

RESUMEN

Polarization-sensitive anisotropic plasmonic interaction between gold nanorods (AuNRs) and quantum dots (QDs) encapsulated in an epoxy resin polymer has been experimentally investigated. The anisotropic plasmonic interaction utilized the polarization-dependent plasmonic properties of aligned AuNR in AuNR-QD composite. AuNRs were aligned by an external AC electric field of 3.5 ×105 Vm-1. The plasmonic interaction modified QD absorption and emission dependent on excitation light polarization and maximum enchantment of 10% and 59%, respectively. Moreover, anisotropic plasmonic interaction induced directional emission of QDs has improved emission decay rate by 20% and modulated emission polarization ratio of out-of-plane (vertical) and in-plane (horizontal) from 1 to 0.84.

7.
Nanomaterials (Basel) ; 10(6)2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32575601

RESUMEN

Exploiting solar energy using photo-thermal (PT) and/or hybridised photovoltaic/thermal (PVT) systems can represent a viable alternative to the growing demand for renewable energy. For large-scale implementation, such systems require thermal fluids able to enhance the combined conversion efficiency achievable by controlling the 'thermal' and 'electrical' components of the solar spectrum. Nanofluids are typically employed for these purposes and they should exhibit high heat-transfer capabilities and optical properties tuned towards the peak performance spectral window of the photovoltaic (PV) component. In this work, novel nanofluids, composed of highly luminescent organic molecules and Ag nanoparticles dispersed within a base fluid, were tested for PT and PVT applications. These nanofluids were designed to mimic the behaviour of luminescent down-shifting molecules while offering enhanced thermo-physical characteristics over the host base fluid. The nanofluids' conversion efficiency was evaluated under a standard AM1.5G weighted solar spectrum. The results revealed that the Ag nanoparticles' inclusion in the composite fluid has the potential to improve the total solar energy conversion. The nanoparticles' presence minimizes the losses in the electrical power component of the PVT systems as the thermal conversion increases. The enhanced performances recorded suggest that these nanofluids could represent suitable candidates for solar energy conversion applications.

8.
Langmuir ; 35(40): 13011-13019, 2019 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-31525940

RESUMEN

A multitude of applications is related to the unique properties of absorption, scattering, and plasmon-enhanced phenomena of metal nanoparticles (MNPs). The aqueous colloidal-based synthesis of MNPs is used more widely as it allows precise shape and size control. However, for various applications, it is required to have the MNPs in an organic solvent or polymer that is compatible with the MNPs. This work establishes a protocol from the synthesis to the phase transfer process of gold nanorods and gold core silver shell nanocuboids (Au@Ag NCs) in dichloromethane. Subsequent dispersion in a polymer (silicone encapsulant polymer) is achieved while retaining the MNPs' plasmonic properties. Au@Ag NCs have not been transferred to an organic solvent to date due to their unique shape and instability in the organic phase. The established protocol is reproducible, and MNPs were found to be stable for up to a year in the polymer. Qualitative and quantitative validation of the experimental results is achieved on MNP concentration by a model based on the finite difference time domain method. Using the model, the concentration of MNPs in nanocomposite can be determined.

9.
Front Oncol ; 9: 196, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31024832

RESUMEN

Background: Chimeric antigen receptor (CAR)-modified T cells have successfully harnessed T cell immunity against malignancies, but they are by no means the only cell therapies in development for cancer. Main Text Summary: Systemic immunity is thought to play a key role in combatting neoplastic disease; in this vein, genetic modifications meant to explore other components of T cell immunity are being evaluated. In addition, other immune cells-from both the innate and adaptive compartments-are in various stages of clinical application. In this review, we focus on these non-CAR T cell immunotherapeutic approaches for malignancy. The first section describes engineering T cells to express non-CAR constructs, and the second section describes other gene-modified cells used to target malignancy. Conclusions: CAR T cell therapies have demonstrated the clinical benefits of harnessing our body's own defenses to combat tumor cells. Similar research is being conducted on lesser known modifications and gene-modified immune cells, which we highlight in this review.

10.
Sci Rep ; 8(1): 13386, 2018 09 06.
Artículo en Inglés | MEDLINE | ID: mdl-30190507

RESUMEN

Chronic infection with opportunistic pathogens including Burkholderia cepacia complex (Bcc) is a hallmark of cystic fibrosis (CF). We investigated the adaptive mechanisms facilitating chronic lung infection in sequential Bcc isolates from two siblings with CF (P1 and P2), one of whom also experienced intermittent blood-stream infections (P2). We previously showed increased lung cell attachment with colonisation time in both P1 and P2. WGS analysis confirmed that the isolates are closely related. Twelve genes showed three or more mutations, suggesting these were genes under selection. Single nucleotide polymorphisms (SNVs) in 45 regulatory genes were also observed. Proteomic analysis showed that the abundance of 149 proteins increased over 61-months in sputum isolates, and both time- and source-related alterations in protein abundance between the second patient's isolates. A consistent time-dependent increase in abundance of 19 proteins encoded by a low-oxygen-activated (lxa) locus was observed in both sets of isolates. Attachment was dramatically reduced in a B. cenocepacia K56-2Δlxa-locus deletion mutant, further indicating that it encodes protein(s) involved in host-cell attachment. Time-related changes in virulence in Galleria mellonella or motility were not observed. We conclude that the lxa-locus, associated with anoxic persistence in vitro, plays a role in host-cell attachment and adaptation to chronic colonization in the hypoxic niche of the CF lung.


Asunto(s)
Adaptación Fisiológica , Infecciones por Burkholderia , Burkholderia cenocepacia , Fibrosis Quística , Sitios Genéticos , Oxígeno/metabolismo , Neumonía Bacteriana , Secuencia de Bases , Infecciones por Burkholderia/genética , Infecciones por Burkholderia/metabolismo , Infecciones por Burkholderia/microbiología , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/metabolismo , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Fibrosis Quística/microbiología , Femenino , Humanos , Pulmón/metabolismo , Pulmón/microbiología , Masculino , Neumonía Bacteriana/genética , Neumonía Bacteriana/metabolismo , Neumonía Bacteriana/microbiología , Polimorfismo de Nucleótido Simple , Eliminación de Secuencia
11.
Biol Blood Marrow Transplant ; 24(9): 1944-1946, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29753156

RESUMEN

Viral infections can be life threatening in patients with severe combined immunodeficiency (SCID) and other forms of profound primary immunodeficiency disorders both before and after hematopoietic stem cell transplantation (HSCT). Adoptive immunotherapy with virus-specific T cells (VSTs) has been utilized in many patients in the setting of HSCT, but has very rarely been attempted for treatment of viral infections before HSCT. Here we describe the use of VSTs in an infant with RAG1 SCID who had developed disseminated adenovirus which failed to improve on cidofovir. Adenovirus cleared following 2 doses of VSTs and marrow infusion from a matched unrelated donor, without incidence of graft versus host disease. T cell receptor-b sequencing demonstrated expansion of adenovirus-specific T cell fraction of the VSTs, suggesting that infusion facilitated viral clearance. This report suggests that VSTs are likely safe in the pre-HSCT period, and may be a useful bridge therapy for infants with SCID and persistent viral infections.


Asunto(s)
Adenoviridae/patogenicidad , Antivirales/uso terapéutico , Inmunodeficiencia Combinada Grave/terapia , Virosis/virología , Antivirales/farmacología , Femenino , Humanos , Lactante , Masculino , Inmunodeficiencia Combinada Grave/patología
12.
Cytotherapy ; 20(3): 385-393, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29331266

RESUMEN

Human papilloma virus (HPV) is a known cause of cervical cancer, squamous cell carcinoma and laryngeal cancer. Although treatments exist for HPV-associated malignancies, patients unresponsive to these therapies have a poor prognosis. Recent findings from vaccine studies suggest that T-cell immunity is essential for disease control. Because Epstein-Barr Virus (EBV)-specific T cells have been highly successful in treating or preventing EBV-associated tumors, we hypothesized that the development of a manufacturing platform for HPV-specific T cells from healthy donors could be used in a third-party setting to treat patients with high-risk/relapsed HPV-associated cancers. Most protocols for generating virus-specific T cells require prior exposure of the donor to the targeted virus and, because the seroprevalence of high-risk HPV types varies greatly by age and ethnicity, manufacturing of donor-derived HPV-specific T cells has proven challenging. We, therefore, made systematic changes to our current Good Manufacturing Practice (GMP)-compliant protocols to improve antigen presentation, priming and expansion for the manufacture of high-efficacy HPV-specific T cells. Like others, we found that current methodologies fail to expand HPV-specific T cells from most healthy donors. By optimizing dendritic cell maturation and function with lipopolysaccharide (LPS) and interferon (IFN)γ, adding interleukin (IL)-21 during priming and depleting memory T cells, we achieved reliable expansion of T cells specific for oncoproteins E6 and E7 to clinically relevant amounts (mean, 578-fold expansion; n = 10), which were polyfunctional based on cytokine multiplex analysis. In the third-party setting, such HPV-specific T-cell products might serve as a potent salvage therapy for patients with HPV-associated diseases.


Asunto(s)
Inmunoterapia/métodos , Papillomaviridae/inmunología , Linfocitos T/inmunología , Células Cultivadas , Células Dendríticas/inmunología , Células Dendríticas/virología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Huésped Inmunocomprometido , Interferón gamma/farmacología , Interleucinas/farmacología , Antígenos Comunes de Leucocito/metabolismo , Lipopolisacáridos/farmacología , Proteínas Oncogénicas Virales/farmacología , Proteínas E7 de Papillomavirus/farmacología , Proteínas Represoras/farmacología , Linfocitos T/citología , Linfocitos T/efectos de los fármacos , Linfocitos T/fisiología
13.
Immun Ageing ; 13: 15, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27134635

RESUMEN

BACKGROUND: Molecular and genetic studies in model organisms have recently revealed a dynamic interplay between immunity and ageing mechanisms. In the fruit fly Drosophila melanogaster, inhibition of the insulin/insulin-like growth factor signaling pathway prolongs lifespan, and mutations in the insulin receptor substrate Chico extend the survival of mutant flies against certain bacterial pathogens. Here we investigated the immune phenotypes, immune signaling activation and immune function of chico mutant adult flies against the virulent insect pathogen Photorhabdus luminescens as well as to non-pathogenic Escherichia coli bacteria. RESULTS: We found that D. melanogaster chico loss-of-function mutant flies were equally able to survive infection by P. luminescens or E. coli compared to their background controls, but they contained fewer numbers of bacterial cells at most time-points after the infection. Analysis of immune signaling pathway activation in flies infected with the pathogenic or the non-pathogenic bacteria showed reduced transcript levels of antimicrobial peptide genes in the chico mutants than in controls. Evaluation of immune function in infected flies revealed increased phenoloxidase activity and melanization response to P. luminescens and E. coli together with reduced phagocytosis of bacteria in the chico mutants. Changes in the antibacterial immune function in the chico mutants was not due to altered metabolic activity. CONCLUSIONS: Our results indicate a novel role for chico in the regulation of the antibacterial immune function in D. melanogaster. Similar studies will further contribute to a better understanding of the interconnection between ageing and immunity and lead to the identification and characterization of the molecular host components that modulate both important biological processes.

14.
Sci Total Environ ; 472: 444-53, 2014 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-24309424

RESUMEN

Soil is the vital foundation of terrestrial ecosystems storing water, nutrients, and almost three-quarters of the organic carbon stocks of the Earth's biomes. Soil organic carbon (SOC) stocks vary with land-cover and land-use change, with significant losses occurring through disturbance and cultivation. Although urbanisation is a growing contributor to land-use change globally, the effects of urban land-cover types on SOC stocks have not been studied for densely built cities. Additionally, there is a need to resolve the direction and extent to which greenspace management such as tree planting impacts on SOC concentrations. Here, we analyse the effect of land-cover (herbaceous, shrub or tree cover), on SOC stocks in domestic gardens and non-domestic greenspaces across a typical mid-sized U.K. city (Leicester, 73 km(2), 56% greenspace), and map citywide distribution of this ecosystem service. SOC was measured in topsoil and compared to surrounding extra-urban agricultural land. Average SOC storage in the city's greenspace was 9.9 kg m(-2), to 21 cm depth. SOC concentrations under trees and shrubs in domestic gardens were greater than all other land-covers, with total median storage of 13.5 kg m(-2) to 21 cm depth, more than 3 kg m(-2) greater than any other land-cover class in domestic and non-domestic greenspace and 5 kg m(-2) greater than in arable land. Land-cover did not significantly affect SOC concentrations in non-domestic greenspace, but values beneath trees were higher than under both pasture and arable land, whereas concentrations under shrub and herbaceous land-covers were only higher than arable fields. We conclude that although differences in greenspace management affect SOC stocks, trees only marginally increase these stocks in non-domestic greenspaces, but may enhance them in domestic gardens, and greenspace topsoils hold substantial SOC stores that require protection from further expansion of artificial surfaces e.g. patios and driveways.


Asunto(s)
Agricultura/estadística & datos numéricos , Secuestro de Carbono , Carbono/análisis , Monitoreo del Ambiente , Suelo/química , Ciudades , Agricultura Forestal/métodos , Urbanización/tendencias
15.
Biol Lett ; 7(5): 771-4, 2011 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-21508018

RESUMEN

Soil compaction adversely influences most terrestrial ecosystem services on which humans depend. This global problem, affecting over 68 million ha of agricultural land alone, is a major driver of soil erosion, increases flood frequency and reduces groundwater recharge. Agricultural soil compaction has been intensively studied, but there are no systematic studies investigating the extent of compaction in urban ecosystems, despite the repercussions for ecosystem function. Urban areas are the fastest growing land-use type globally, and are often assumed to have highly compacted soils with compromised functionality. Here, we use bulk density (BD) measurements, taken to 14 cm depth at a citywide scale, to compare the extent of surface soil compaction between different urban greenspace classes and agricultural soils. Urban soils had a wider BD range than agricultural soils, but were significantly less compacted, with 12 per cent lower mean BD to 7 cm depth. Urban soil BD was lowest under trees and shrubs and highest under herbaceous vegetation (e.g. lawns). BD values were similar to many semi-natural habitats, particularly those underlying woody vegetation. These results establish that, across a typical UK city, urban soils were in better physical condition than agricultural soils and can contribute to ecosystem service provision.


Asunto(s)
Ecosistema , Suelo , Urbanización , Reino Unido
16.
Opt Express ; 16(26): 21773-92, 2008 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-19104611

RESUMEN

Luminescent solar concentrators (LSCs) generally consist of transparent polymer sheets doped with luminescent species. Incident sunlight is absorbed by the luminescent species and emitted with high quantum efficiency, such that emitted light is trapped in the sheet and travels to the edges where it can be collected by solar cells. LSCs offer potentially lower cost per Wp. This paper reviews results mainly obtained within the framework of the Full-spectrum project. Two modeling approaches are presented, i.e., a thermodynamic and a ray-trace one, as well as experimental results, with a focus on LSC stability.

17.
Sleep ; 30(11): 1417-25, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18041476

RESUMEN

STUDY OBJECTIVE: People with narcolepsy and mice lacking orexin/hypocretin have disrupted sleep/wake behavior and reduced physical activity. Our objective was to identify physiologic mechanisms through which orexin deficiency reduces locomotor activity. DESIGN: We examined spontaneous wheel running activity and its relationship to sleep/wake behavior in wild type (WT) and orexin knockout (KO) mice. Additionally, given that physical activity promotes alertness, we also studied whether orexin deficiency reduces the wake-promoting effects of exercise. MEASUREMENTS AND RESULTS: Orexin KO mice ran 42% less than WT mice. Their ability to run appeared normal as they initiated running as often as WT mice and ran at normal speeds. However, their running bouts were considerably shorter, and they often had cataplexy or quick transitions into sleep after running. Wheel running increased the total amount of wakefulness in WT and orexin KO mice similarly, however, KO mice continued to have moderately fragmented sleep/wake behavior. Wheel running also doubled the amount of cataplexy by increasing the probability of transitioning into cataplexy. CONCLUSIONS: Orexin KO mice run significantly less than normal, likely due to sleepiness, imminent cataplexy, or a reduced motivation to run. Orexin is not required for the wake-promoting effects of wheel running given that both WT and KO mice had similar increases in wakefulness with running wheels. In addition, the clear increase in cataplexy with wheel running suggests the possibility that positive emotions or reward can trigger murine cataplexy, similar to that seen in people and dogs with narcolepsy.


Asunto(s)
Cataplejía/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neuropéptidos/metabolismo , Carrera , Vigilia/fisiología , Afecto , Animales , Electroencefalografía , Electromiografía , Locomoción , Masculino , Ratones , Ratones Noqueados , Motivación , Actividad Motora , Obesidad/metabolismo , Orexinas
18.
J Comp Neurol ; 494(5): 845-61, 2006 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-16374809

RESUMEN

Emotions, stress, hunger, and circadian rhythms all promote wakefulness and behavioral arousal. Little is known about the pathways mediating these influences, but the orexin-producing neurons of the hypothalamus may play an essential role. These cells heavily innervate many wake-promoting brain regions, and mice lacking the orexin neurons have narcolepsy and fail to rouse in response to hunger (Yamanaka et al. [2003] Neuron 38:701-713). To identify the afferents to the orexin neurons, we first injected a retrograde tracer into the orexin neuron field of rats. Retrogradely labeled neurons were abundant in the allocortex, claustrum, lateral septum, bed nucleus of the stria terminalis, and in many hypothalamic regions including the preoptic area, dorsomedial nucleus, lateral hypothalamus, and posterior hypothalamus. Retrograde labeling in the brainstem was generally more modest, but labeling was strong in the periaqueductal gray matter, dorsal raphe nucleus, and lateral parabrachial nucleus. Injection of an anterograde tracer confirmed that most of these regions directly innervate the orexin neurons, with some of the heaviest input coming from the lateral septum, preoptic area, and posterior hypothalamus. In addition, hypothalamic regions preferentially innervate orexin neurons in the medial and perifornical parts of the field, but most projections from the brainstem target the lateral part of the field. Inputs from the suprachiasmatic nucleus are mainly relayed via the subparaventricular zone and dorsomedial nucleus. These observations suggest that the orexin neurons may integrate a variety of interoceptive and homeostatic signals to increase behavioral arousal in response to hunger, stress, circadian signals, and autonomic challenges.


Asunto(s)
Vías Aferentes/citología , Encéfalo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neuropéptidos/metabolismo , Vigilia/fisiología , Vías Aferentes/metabolismo , Animales , Encéfalo/citología , Tronco Encefálico/citología , Tronco Encefálico/metabolismo , Hipocampo/citología , Hipocampo/metabolismo , Hipotálamo/citología , Hipotálamo/metabolismo , Masculino , Orexinas , Ratas , Ratas Sprague-Dawley , Telencéfalo/citología , Telencéfalo/metabolismo
19.
J Neurosci ; 24(28): 6291-300, 2004 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-15254084

RESUMEN

Narcolepsy is caused by a lack of orexin (hypocretin), but the physiologic process that underlies the sleepiness of narcolepsy is unknown. Using orexin knock-out (KO) mice as a model of narcolepsy, we critically tested the three leading hypotheses: poor circadian control of sleep and wakefulness, inadequate activation of arousal regions, or abnormal sleep homeostasis. Compared with wild-type (WT) littermates, orexin KO mice had essentially normal amounts of sleep and wake, but wake and non-rapid eye movement (NREM) bouts were very brief, with many more transitions between all behavioral states. In constant darkness, orexin KO mice had normal amplitude and timing of sleep-wake rhythms, providing no evidence for disordered circadian control. When placed in a new, clean cage, both groups of mice remained awake for approximately 45 min, demonstrating that, even in the absence of orexin, fundamental arousal regions can be engaged to produce sustained wakefulness. After depriving mice of sleep for 2-8 hr, orexin KO mice recovered their NREM and rapid eye movement sleep deficits at comparable rates and to the same extent as WT mice, with similar increases in EEG delta power, suggesting that their homeostatic control of sleep is normal. These experiments demonstrate that the fragmented wakefulness of orexin deficiency is not a consequence of abnormal sleep homeostasis, poor circadian control, or defective fundamental arousal systems. Instead, the fragmented behavior of orexin KO mice may be best described as behavioral state instability, with apparently low thresholds to transition between states.


Asunto(s)
Conducta Animal/fisiología , Péptidos y Proteínas de Señalización Intracelular/deficiencia , Narcolepsia/fisiopatología , Neuropéptidos/deficiencia , Animales , Nivel de Alerta/genética , Nivel de Alerta/fisiología , Cataplejía/genética , Cataplejía/fisiopatología , Ritmo Circadiano/genética , Ritmo Circadiano/fisiología , Modelos Animales de Enfermedad , Electroencefalografía , Electromiografía , Homeostasis/genética , Homeostasis/fisiología , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Neurológicos , Narcolepsia/genética , Neuropéptidos/genética , Neuropéptidos/fisiología , Orexinas , Privación de Sueño/fisiopatología , Fases del Sueño/genética , Fases del Sueño/fisiología , Sueño REM/fisiología , Estrés Psicológico/fisiopatología , Vigilia/genética , Vigilia/fisiología
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