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1.
Phys Rev Lett ; 129(2): 021803, 2022 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-35867435

RESUMEN

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, probes nuclear effects that govern neutrino-nucleus interactions. This Letter reports the first measurement of the triple-differential cross section for ν_{µ} quasielastic-like reactions using the hydrocarbon medium of the MINERvA detector exposed to a wideband beam spanning 2≤E_{ν}≤20 GeV. The measurement maps the correlations among transverse and longitudinal muon momenta and summed proton kinetic energies, and compares them to predictions from a state-of-art simulation. Discrepancies are observed that likely reflect shortfalls with modeling of pion and nucleon intranuclear scattering and/or spectator nucleon ejection from struck nuclei. The separate determination of leptonic and hadronic variables can inform experimental approaches to neutrino-energy estimation.

2.
J Environ Manage ; 319: 115676, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35839648

RESUMEN

Providing sufficient benefits to local people can be an important component of effective and equitable conservation, especially where local communities face substantial opportunity costs or disbenefits from conservation. However, the distribution of benefits to local people is often inadequate or inequitable. In this study we investigated the heterogeneity in the extent to which people living near Hwange National Park (HNP), Zimbabwe, perceive benefit from the presence of the park. Specifically, we examined the relationships between a diverse set of candidate predictor variables and perceived benefit from HNP. Our candidate predictor variables broadly relate to personal assets, social capital, value orientation, fear of lions, and belief and participation in human-wildlife conflict mitigation schemes. One third of respondents reported that their household experienced at least some benefits from HNP. Of all respondents, 6% perceived their household to benefit strongly from HNP and 2% very strongly. Livestock loss to wildlife was the most important factor for predicting perceived benefit, with those suffering more loss less likely to perceive benefit. Multiple demographic factors predicted perceived benefit with, for instance, older people and those with less education perceiving less benefit. Employment in conservation-related work positively affected perceived benefit, whereas fear of lions had a negative impact. Social capital appeared to have a positive influence on perceived benefit from HNP. The relationship between social capital and perceived benefit was positive and plateauing, which suggests that social capital is especially impactful on the benefit perceived by individuals reporting the least social capital. We also found a positive association between belief in compensation schemes and perceived benefit from HNP. We posit hypotheses for this association but are unable to determine the underlying drivers of this relationship. Finally, participation in the community guardians programme, a human-lion conflict mitigation programme, was positively related to perceived benefit from HNP. Thus, our findings emphasise the value of considering a diverse array of factors when investigating park-people relationships and yield insights for improving the equitability of conservation in and around HNP and similar systems.


Asunto(s)
Ganado , Capital Social , Anciano , Animales , Animales Salvajes , Conservación de los Recursos Naturales , Miedo , Humanos
3.
J Dairy Sci ; 104(2): 1548-1559, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33309341

RESUMEN

Textiles represent promising support materials for enzymes. The goal of the present work was to investigate the immobilization of commercial peroxidase on a polyester needle felt and the repeated use in the gentle degradation of norbixin in whey from dairy cheese as a practical application. High enzyme loads were obtained by a 2-step immobilization procedure. First, the number of functional groups on the textile surface was increased by a modification with amino-functional polyvinylamine. Second, the enzyme was immobilized by using 2 types of crosslinking agents. Due to the iron content of peroxidase, inductively coupled plasma-optical emission spectrometry was used for the quantitative determination of the enzyme load on the textile. The enzyme activity was evaluated using common 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulfonic acid) assay for peroxidases. By the variation of enzyme input and crosslinker concentration, a maximal enzyme load of 80 mg/g of textile was achieved, and a maximum specific activity of 57 U/g of textile. For the visualization of the enzyme on the fiber surface, fluorescence microscopy as well as scanning probe microscopy were used. The immobilized peroxidase showed significant activity, even after 50 reuse cycles. In addition, the potential of the new support and enzyme combination in commercial whey bleaching was demonstrated successfully on a 10-L scale.


Asunto(s)
Blanqueadores/química , Carotenoides/metabolismo , Queso , Peroxidasa/química , Suero Lácteo/química , Blanqueadores/metabolismo , Color , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Peroxidasa/metabolismo , Poliésteres/química , Textiles
4.
Parasitol Res ; 120(2): 743-746, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33409625

RESUMEN

The probiotic medicinal product TSO (Trichuris suis ova) is administered to patients with active ulcerative colitis in an ongoing clinical phase IIb trial where the typical co-medications are steroids (prednisolone or budesonide) and antibiotics (e.g., phenoxymethylpenicillin). The present pre-clinical study evaluates the effects of these co-medications on the biological activity of TSO in Göttingen Minipigs. This translationally relevant pre-clinical model allows administration of TSO with and without oral steroids or antibiotics in a manner similar to the administration to patients, followed by quantification of the biological activity of TSO. The biological activity of TSO was not affected by oral steroids but was reduced by oral antibiotics. Fecal calprotectin, the common marker of intestinal inflammation in patients with UC, did not differ between groups.


Asunto(s)
Antibacterianos/uso terapéutico , Probióticos/uso terapéutico , Esteroides/uso terapéutico , Trichuris , Animales , Antibacterianos/farmacología , Colitis Ulcerosa/terapia , Modelos Animales de Enfermedad , Femenino , Óvulo/efectos de los fármacos , Esteroides/farmacología , Porcinos , Porcinos Enanos , Trichuris/efectos de los fármacos
5.
Clin Exp Immunol ; 197(1): 74-82, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30821848

RESUMEN

New therapies, including the anti-cytotoxic T lymphocyte antigen (CTLA)-4 antibody, ipilimumab, is approved for metastatic melanoma. Prognostic biomarkers need to be identified, because the treatment has serious side effects. Serum samples were obtained before and during treatment from 56 patients with metastatic or unresectable malignant melanoma, receiving treatment with ipilimumab in a national Phase IV study (NCT0268196). Expression of a panel of 17 inflammatory-related markers reflecting different pathways including extracellular matrix remodeling and fibrosis, vascular inflammation and monocyte/macrophage activation were measured at baseline and the second and/or third course of treatment with ipilimumab. Six candidate proteins [endostatin, osteoprotegerin (OPG), C-reactive protein (CRP), pulmonary and activation-regulated chemokine (PARC), growth differentiation factor 15 (GDF15) and galectin-3 binding-protein (Gal3BP)] were persistently higher in non-survivors. In particular, high Gal3BP and endostatin levels were also independently associated with poor 2-year survival after adjusting for lactate dehydrogenase, M-stage and number of organs affected. A 1 standard deviation increase in endostatin gave 1·74 times [95% confidence interval (CI) = 1·10-2·78, P = 0·019] and for Gal3BP 1·52 times (95% CI = 1·01-2·29, P = 0·047) higher risk of death in the adjusted model. Endostatin and Gal3BP may represent prognostic biomarkers for patients on ipilimumab treatment in metastatic melanoma and should be further evaluated. Owing to the non-placebo design, we could only relate our findings to prognosis during ipilimumab treatment.


Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Ipilimumab/uso terapéutico , Melanoma/secundario , Melanoma/terapia , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/sangre , Femenino , Humanos , Inmunoterapia/métodos , Mediadores de Inflamación/sangre , Estimación de Kaplan-Meier , Masculino , Melanoma/sangre , Persona de Mediana Edad , Pronóstico
6.
West Indian Med J ; 64(3): 266-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26426181

RESUMEN

OBJECTIVE: To examine the relationship between infrequent toothbrushing and infrequent handwashing among middle school students from 15 Latin American and Caribbean countries (Antigua and Barbuda, Argentina, British Virgin Islands, Cayman Islands, Costa Rica, Grenada, Guatemala, Guyana, Peru, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and Grenadines, Suriname, Trinidad and Tobago, and Uruguay). METHODS: A secondary analysis was done of nationally-representative data from 33 174 middle school students who participated in the Global School-based Student Health Survey (GSHS) between 2006 and 2011. RESULTS: In all 15 countries, the association between rarely brushing or cleaning teeth and rarely handwashing after using the toilet was significant for both boys and girls. The pooled odds ratio for this association was 6.7 (5.8, 7.7). CONCLUSION: Healthcare providers who notice signs of poor dental hygiene or infrequent bathing in adolescents should consider providing comprehensive hygiene education to their patients, since infrequent oral and body hygiene behaviours tend to co-exist and both are threats to health.

7.
Pflugers Arch ; 465(12): 1753-62, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23832500

RESUMEN

Members of the TMEM16 family have recently been described as Ca(2+)-activated Cl(-) channels. They have been implicated in cancer and appear to be associated with poor patient prognosis. Here, we investigate the role of TMEM16 channels in cell migration, which is largely unknown. We focused on TMEM16A and TMEM16F channels that have the highest expression of TMEM16 channels in Ehrlich Lettre ascites (ELA) cells. Due to the lack of specific pharmacological modulators, we employed a miRNA approach and stably knocked down the expression of TMEM16A and TMEM16F channels, respectively. Migration analysis shows that TMEM16A KD clones are affected in their directional migration, whereas TMEM16F KD clones show a 40 % reduced rate of cell migration. Moreover, TMEM16A KD clones have a smaller projected cell area, and they are rounder than TMEM16F KD clones. The morphological changes are linearly correlated with the directionality of cells. TMEM16A and TMEM16F, thus, have an important function in cell migration-TMEM16A in directional migration, TMEM16F in determination of the speed of migration. We conclude that TMEM16A and TMEM16F channels have a distinct impact on the steering and motor mechanisms of migrating ELA cells.


Asunto(s)
Movimiento Celular/fisiología , Canales de Cloruro/fisiología , Proteínas de Transferencia de Fosfolípidos/fisiología , Animales , Anoctamina-1 , Anoctaminas , Carcinoma de Ehrlich , Técnicas de Silenciamiento del Gen , Ratones
8.
J Med Primatol ; 42(3): 137-46, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23530983

RESUMEN

BACKGROUND: In an attempt to explore cynomolgus monkeys as an animal model for Alzheimer's disease, the present study focused on the Alzheimer's biomarkers beta amyloid 1-42 (Aß42 ) in serum, and total tau (t-tau) and phosphorylated tau (p-tau) levels in cerebrospinal fluid. METHODS: We measured biomarker levels in Young and Aged cynomolgus monkeys and correlated these with performance on three delayed response tasks. RESULTS: The Aß42 concentration of the Aged monkeys was significantly lower than in the Young subjects, while the t-tau and p-tau did not significantly differ between the groups. The Young subjects performed significantly better than the Aged individuals on the memory tests. Only Aß42 levels were significantly correlated with performance in the three delayed response tasks. CONCLUSIONS: Circulating Aß42 levels were lower in Aged monkeys and were correlated with inferior performance on delayed response tasks in Aged animals; therefore, both measures may be useful in establishing cynomolgus monkeys as models for studies of AD.


Asunto(s)
Envejecimiento , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/psicología , Modelos Animales de Enfermedad , Macaca fascicularis , Memoria , Enfermedad de Alzheimer/líquido cefalorraquídeo , Péptidos beta-Amiloides/sangre , Animales , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Femenino , Masculino , Fragmentos de Péptidos/sangre , Proteínas tau/líquido cefalorraquídeo
9.
East Mediterr Health J ; 19(3): 227-33, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23879073

RESUMEN

Bullying, especially in developing countries, has not been much examined, especially the influence of parents on the risk of being bullied. The aim of this study was to determine whether active parenting is associated with reduced peer victimization among middle-school students in North Africa. A secondary analysis of data from more than 13,000 middle-school students who participated in the Global School-based Student Health Survey (GSHS) in Egypt, Libya, Morocco and Tunisia between 2006 and 2008, was conducted using multiple logistic regression models. About 60% of students in Egypt and one-third of students in Libya, Morocco and Tunisia reported having been bullied in the past month. In all 4 countries, boys reported more peer victimization than girls. In Egypt, Morocco and Tunisia, students who reported that their parents checked their homework, were understanding, and knew how the student spent free time had a reduced likelihood of peer victimization but this association was not significant in Libya. Interventions for reducing bullying should consider the positive impact of involved parents.


Asunto(s)
Acoso Escolar/psicología , Víctimas de Crimen/psicología , Relaciones Padres-Hijo , Adolescente , África del Norte , Niño , Víctimas de Crimen/estadística & datos numéricos , Comparación Transcultural , Femenino , Humanos , Masculino , Grupo Paritario , Distribución por Sexo , Estudiantes/estadística & datos numéricos , Encuestas y Cuestionarios
10.
West Indian Med J ; 61(5): 504-8, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23441373

RESUMEN

OBJECTIVE: To examine the relationships between peer victimization, mental health, and parental involvement among middle school students in the Caribbean. METHODS: Data from the Global School-based Student Health Survey (GSHS) conducted in the Cayman Islands, St Lucia, St Vincent and the Grenadines, and Trinidad and Tobago in 2007 were analysed using age- and gender-adjusted logistic regression models. RESULTS: About one-quarter of the 6780 participants reported having been bullied in the past month. Rates of bullying were similar for boys and girls, and younger children reported higher rates of peer victimization. Nearly 25% of students reported sadness and hopelessness, more than 10% reported loneliness and anxiety and more than 15% reported having seriously considered suicide in the past year. Bullied students were much more likely than non-bullied students to report mental health issues (p < 0.01). Students who felt that their parents were understanding and monitored their free time activities reported fewer mental health issues and were somewhat less likely to report being a victim of a bully. CONCLUSION: The strong association between bullying and poor mental health in the Caribbean emphasizes the need to develop and implement strategies for reducing bullying among children and adolescents.


Asunto(s)
Acoso Escolar/psicología , Trastornos Mentales/psicología , Relaciones Padres-Hijo , Adolescente , Afecto , Emociones , Femenino , Humanos , Masculino , Ideación Suicida , Indias Occidentales
11.
ESMO Open ; 7(5): 100588, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36116420

RESUMEN

BACKGROUND: We have previously reported that the safety and efficacy of ipilimumab in real-world patients with metastatic melanoma were comparable to clinical trials. Few studies have explored health-related quality of life (HRQL) in real-world populations receiving checkpoint inhibitors. This study reports HRQL in real-world patients receiving ipilimumab and assesses the prognostic value of patient-reported outcome measures. PATIENTS AND METHODS: Ipi4 (NCT02068196) was a prospective, multicentre, interventional phase IV trial. Real-world patients (N = 151) with metastatic melanoma were treated with ipilimumab 3 mg/kg intravenously as labelled. HRQL was assessed by the European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire at baseline and after 10-12 weeks. RESULTS: The European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire was completed by 93% (141/151 patients) at baseline, and by 82% at 10-12 weeks. Poor performance status and elevated C-reactive protein (CRP) were associated with worse baseline HRQL. Clinically relevant and statistically significant deteriorations in HRQL from baseline to weeks 10-12 were reported (P <0.05). Baseline physical functioning [hazard ratio (HR) 1.96, P = 0.016], role functioning (HR 2.15, P <0.001), fatigue (HR 1.60, P = 0.030), and appetite loss (HR 1.76, P = 0.012) were associated with poorer overall survival independent of performance status, lactate dehydrogenase (LDH), and CRP. We further developed a prognostic model, combining HRQL outcomes with performance status, LDH, and CRP. This model identified three groups with large and statistically significant differences in survival. CONCLUSIONS: Systemic inflammation is associated with impaired HRQL. During treatment with ipilimumab, HRQL deteriorated significantly. Combining HRQL outcomes with objective risk factors provided additional prognostic information that may aid clinical decision making.


Asunto(s)
Melanoma , Calidad de Vida , Humanos , Ipilimumab/farmacología , Ipilimumab/uso terapéutico , Pronóstico , Estudios Prospectivos , Proteína C-Reactiva , Melanoma/tratamiento farmacológico , Melanoma/secundario , L-Lactato Deshidrogenasa
12.
J Exp Med ; 181(1): 105-13, 1995 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-7806997

RESUMEN

The vast majority of lymphocytes generated daily in the chicken bursa of Fabricius do not emigrate to the periphery but die in situ. Apoptotic cells in the bursa can be readily detected by the presence of fragmented DNA and by the large numbers of condensed cellular nuclei observed by electron microscopy. Consequently, most newly generated lymphocytes die by programmed cell death. We show that bursal cells divide rapidly and apoptotic cells are derived from rapidly dividing precursors. Analysis of the phenotype of bursal cells undergoing apoptosis demonstrated that cell death does not occur in the most mature bursal cell population and is therefore not random. High levels of surface Ig are expressed on bursal cells entering S phase of the cell cycle. In contrast, bursal cells in the early stages of apoptosis in vivo express very low to undetectable levels of surface Ig but were unequivocally confirmed as being of the B lineage by polymerase chain reaction (PCR) detection of rearranged Ig genes. Bursal cells induced to undergo apoptosis in vitro express high levels of surface Ig demonstrating that induction of apoptosis does not in itself induce a loss of surface Ig expression. Consequently, loss of surface Ig expression precedes bursal cell death by apoptosis in vivo, suggesting that maintenance of a threshold level of surface Ig may be a requirement for the continued progression of chicken B lymphocyte development in the bursa.


Asunto(s)
Apoptosis , Linfocitos B/citología , Bolsa de Fabricio/citología , Receptores de Antígenos de Linfocitos B/metabolismo , Animales , Linfocitos B/metabolismo , Secuencia de Bases , Pollos , Cartilla de ADN/química , Reordenamiento Génico de Cadena Pesada de Linfocito B , Reordenamiento Génico de Cadena Ligera de Linfocito B , Genes de Inmunoglobulinas , Datos de Secuencia Molecular
13.
J Exp Med ; 176(4): 927-35, 1992 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-1383380

RESUMEN

B lymphocyte precursor cells in mouse bone marrow develop in close association with stromal cells which provide essential growth signals. To identify molecules that may normally play a role in this interaction we have examined the in vivo binding of a new monoclonal antibody (mAb) (KMI6) that recognizes a determinant on a bone marrow stromal cell line (BMS2) in vitro. Flow cytometric and radioautographic evaluations revealed that the antigen recognized by KMI6 is represented on the surface of an extremely small number of cells in bone marrow cell suspensions from adult mice. An apparent molecular mass of 110 kD was obtained by surface labeling of a stromal cell clone and immunoprecipitation. Purified mAb KMI6 labeled with 125I was then given intravenously to young C3H/HeJ mice. Unbound mAb was washed out by cardiac perfusion and femoral bone marrow was examined by light and electron microscope radioautography. KMI6 labeling was heavy on the plasma membrane of many stromal cells, especially those located towards the outer subosteal region. The KMI6-labeled stromal cells were usually associated with cells of lymphoid morphology which they often completely surrounded. The labeling was restricted to areas of stromal cell plasma membranes in contact with lymphoid cells. The lymphoid cells themselves, as well as macrophages and other hemopoietic cells, failed to bind mAb KMI6 significantly. Stromal cells in bone marrow depleted of hemopoietic cells by gamma-irradiation (9,5 Gy) bound mAb KMI6 at reduced intensity. The results demonstrate that the KMI6 determinant, a 110-kD protein, is expressed on bone marrow stromal cells in vivo. Its restriction to areas of interaction with lymphoid cells suggests a role in forming microenvironmental niches of B lymphopoiesis. The surface membrane of individual stromal cells may thus be functionally polarized towards interacting B cell precursors and other hemopoietic cells.


Asunto(s)
Células de la Médula Ósea , Animales , Anticuerpos Monoclonales , Antígenos/análisis , Linfocitos B/citología , Médula Ósea/efectos de la radiación , Médula Ósea/ultraestructura , Células Clonales , Epítopos/análisis , Rayos gamma , Células Madre Hematopoyéticas/ultraestructura , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos , Microscopía Inmunoelectrónica , Células del Estroma/citología , Células del Estroma/efectos de la radiación , Células del Estroma/ultraestructura
14.
J Chem Phys ; 132(7): 071101, 2010 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-20170208

RESUMEN

We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery. Using density functional theory to estimate the free energy of intermediates during the discharge and charge of the battery, we introduce a reaction free energy diagram and identify possible origins of the overpotential for both processes. We also address the question of electron conductivity through the Li(2)O(2) electrode and show that in the presence of Li vacancies Li(2)O(2) becomes a conductor.

15.
Enzyme Microb Technol ; 136: 109512, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32331717

RESUMEN

A textile-based reaction system for new peroxidase reactions in non-native media was implemented. The epoxidation of cyclohexene by the commercial peroxidase MaxiBright® was realized with the textile-immobilized enzyme in an adapted liquid-liquid two-phase reactor. A commercially available polyester felt was used as low-price carrier and functionalized with polyvinyl amine. The covalent immobilization with glutardialdehyde lead to an enzyme loading of 0.10 genzyme/gtextile. The textile-based peroxidase shows a high activity retention in the presence of organic media. This catalyst is shown to enable the epoxidation of cyclohexene in various solvents as well as under neat conditions. A model reactor was produced by 3D printing which places the textile catalyst at the interphase between the liquid reaction phase and the product extracting solvent.


Asunto(s)
Ciclohexenos/metabolismo , Enzimas Inmovilizadas/metabolismo , Peroxidasas/metabolismo , Textiles , Biocatálisis , Colorantes , Glutaral/metabolismo , Oxidación-Reducción , Solventes/metabolismo
16.
J Med Ethics ; 35(4): 262-7, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19332585

RESUMEN

OBJECTIVE: This paper describes the variety of ways that information about ethics-related methods are included or not included in public health research articles. METHODS: Information about the ethics-related content of all articles published in nine highly-respected public health journals in 2006 was extracted. RESULTS: Of 989 primary analyses, 73% of the articles commented on ethics committee approval or exemption, 63% mentioned participant consent and 9% indicated whether or not inducement or compensation was given. 84% of articles mentioned a funding source, but fewer than 4% identified any potential conflict of interest. Reporting rates for committee review and consent were higher for experimental than for observational studies and were comparatively higher in studies conducted among potentially vulnerable populations like children and residents of low income countries. CONCLUSIONS: More complete reporting would facilitate the design, evaluation and comparison of future research studies.


Asunto(s)
Políticas Editoriales , Publicaciones Periódicas como Asunto/ética , Proyectos de Investigación/normas , Humanos , Publicaciones Periódicas como Asunto/normas
17.
J Phys Condens Matter ; 20(37): 374101, 2008 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-21694409

RESUMEN

The electrical properties of single-molecule junctions, consisting of an organic molecule coupled to metal electrodes, are sensitive to the detailed atomic structure of the molecule-metal contact. This, in turn, is determined by the anchoring group linking the molecule to the metal. With the aim of identifying and comparing the intrinsic properties of two commonly used anchoring groups, namely thiol and amine groups, we have calculated the atomic structure and conductance traces of different Au-S-Au and Au-NH(2)-Au nanojunctions using density functional theory (DFT). Whereas NH(2) shows a strong structural selectivity towards atop-gold configurations, S shows large variability in its bonding geometries. As a result, the conductance of the Au-NH(2)-Au junction is less sensitive to the structure of the gold contacts than the Au-S-Au junction. These findings support recent experiments which show that amine-bonded molecules exhibit more well-defined conductance properties than do thiol-bonded molecules.

18.
Am J Med Genet B Neuropsychiatr Genet ; 147B(8): 1470-5, 2008 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-18081165

RESUMEN

Attention deficit hyperactivity disorder (ADHD) is a common and highly heritable psychiatric disorder in children and adults. Recent meta-analyses have indicated an association between genes involved in dopaminergic signaling and childhood ADHD, but little is known about their possible role in adult ADHD. In this study of adults with ADHD, we evaluated the three most commonly studied ADHD candidate genetic polymorphisms; the dopamine receptor D4 (DRD4) exon 3 VNTR repeat, a microsatellite repeat 18.5 kb upstream of the DRD5 locus and the 3'UTR dopamine transporter SLC6A3 (DAT 1) VNTR. We examined 358 clinically diagnosed adult Norwegian ADHD patients (51% males) and 340 ethnically matched controls. We found a nominally significant overall association with adult ADHD for the DRD5 microsatellite marker (P = 0.04), and a trend toward increased risk associated with the 148-bp allele consistent with recent meta-analyses. The strongest overall association (P = 0.02) and increased risk for the 148-bp allele [odds ratio (OR) = 1.27 (95% CI: 1.00-1.61)] were seen in the inattentive and combined inattentive/hyperactive group as previously reported for childhood ADHD. No association was found for the DRD4 or SLC6A3 polymorphisms in this patient sample. In conclusion, our results among adults with a clinical diagnosis of ADHD support an association between ADHD and the DRD5 locus, but not the DRD4 or SLC6A3 loci. It is possible that the latter polymorphisms are associated with a transient form of ADHD with better long-term clinical outcome.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/genética , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática/genética , Repeticiones de Microsatélite , Receptores de Dopamina D4/genética , Receptores de Dopamina D5/genética , Adulto , Alelos , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Marcadores Genéticos , Humanos , Masculino , Polimorfismo Genético , Estudios Retrospectivos
19.
Mol Cell Biol ; 5(12): 3517-24, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3915778

RESUMEN

Expression of two Saccharomyces cerevisiae genes (YG101 and YG103) that are related to the gene encoding inducible 70K protein (hsp70) is repressed upon heat shock. Mutations of the two genes were constructed in vitro and substituted into the yeast genome in place of the wild-type alleles. No phenotypic effect of single mutations of either gene was detected. However, cells containing both YG101 and YG103 mutations showed altered growth properties; double-mutation cells possess an optimal growth temperature of 37 degrees C rather than 30 degrees C and grow increasingly poorly as the temperature is lowered. Mutations of two other members of this hsp70-related multigene family, YG100 and YG102, have been analyzed (E. A. Craig and K. Jacobsen, Cell 38:841-849, 1984). Cells containing both YG100 and YG102 mutations cannot form colonies at 37 degrees C. Fusions between the YG101 and YG102 promoter regions and the YG100 and YG101 structural genes, respectively, were constructed. The YG101 promoter-YG100 structural gene fusion was not able to restore normal growth properties to the yg101- yg103- mutant. Also, yg100- yg102- cells containing the YG102 promoter-YG101 structural gene fusion were unable to grow at 37 degrees C. Failure of the protein products of related genes to rescue the relative cold sensitivity of growth suggests that members of the hsp70 multigene family are functionally distinct.


Asunto(s)
Genes Fúngicos , Proteínas de Choque Térmico/genética , Saccharomyces cerevisiae/genética , División Celular , Frío , Regulación de la Expresión Génica , Genes , Mutación , Plásmidos , Regiones Promotoras Genéticas , Saccharomyces cerevisiae/citología
20.
Plant Biol (Stuttg) ; 9(6): 776-85, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17682965

RESUMEN

Three types of hemoglobins exist in higher plants, symbiotic, non-symbiotic, and truncated hemoglobins. Symbiotic (class II) hemoglobins play a role in oxygen supply to intracellular nitrogen-fixing symbionts in legume root nodules, and in one case ( Parasponia Sp.), a non-symbiotic (class I) hemoglobin has been recruited for this function. Here we report the induction of a host gene, dgtrHB1, encoding a truncated hemoglobin in Frankia-induced nodules of the actinorhizal plant Datisca glomerata. Induction takes place specifically in cells infected by the microsymbiont, prior to the onset of bacterial nitrogen fixation. A bacterial gene (Frankia trHBO) encoding a truncated hemoglobin with O (2)-binding kinetics suitable for the facilitation of O (2) diffusion ( ) is also expressed in symbiosis. Nodule oximetry confirms the presence of a molecule that binds oxygen reversibly in D. glomerata nodules, but indicates a low overall hemoglobin concentration suggesting a local function. Frankia trHbO is likely to be responsible for this activity. The function of the D. glomerata truncated hemoglobin is unknown; a possible role in nitric oxide detoxification is suggested.


Asunto(s)
Proteínas Bacterianas/metabolismo , Hemoglobinas/genética , Magnoliopsida/metabolismo , Proteínas de Plantas/genética , Nódulos de las Raíces de las Plantas/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Clonación Molecular , Secuencia Conservada , ADN Complementario/química , ADN Complementario/metabolismo , Frankia/genética , Frankia/metabolismo , Frankia/fisiología , Regulación de la Expresión Génica de las Plantas , Hemoglobinas/metabolismo , Magnoliopsida/genética , Magnoliopsida/microbiología , Fijación del Nitrógeno , Oxígeno/metabolismo , Proteínas de Plantas/análisis , Proteínas de Plantas/metabolismo , Reacción en Cadena de la Polimerasa , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/microbiología , Simbiosis
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