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1.
Phys Rev Lett ; 118(2): 025002, 2017 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-28128587

RESUMO

The effects of laser-plasma interactions (LPI) on the dynamics of inertial confinement fusion hohlraums are investigated via a new approach that self-consistently couples reduced LPI models into radiation-hydrodynamics numerical codes. The interplay between hydrodynamics and LPI-specifically stimulated Raman scatter and crossed-beam energy transfer (CBET)-mostly occurs via momentum and energy deposition into Langmuir and ion acoustic waves. This spatially redistributes energy coupling to the target, which affects the background plasma conditions and thus, modifies laser propagation. This model shows reduced CBET and significant laser energy depletion by Langmuir waves, which reduce the discrepancy between modeling and data from hohlraum experiments on wall x-ray emission and capsule implosion shape.

2.
Radiography (Lond) ; 30(1): 73-79, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37871368

RESUMO

INTRODUCTION: An awareness of Professional Identity (PI), an individual's identity in relation to their professional group, and Role Perception (RP), an individual's view of their specific role, may enable safe and effective practice by providing an understanding of professional boundaries, behaviours and activities. This research aimed to explore and gain an understanding of the PI and RP of Radiographers and Clinical Technologists working as Nuclear Medicine Technologists (NMT's). METHODS: 10 NMT's were recruited from a large National Health Service (NHS) Trust. Utilising the established methodology of Qualitative Description, data was obtained using semi-structured interviews and analysed using inductive thematic analysis. RESULTS: Four themes were identified: "Becoming the Unexpected" which detailed various training pathways; "Caring with Science" which described the NMT's role and defined their PI; "Same View, Different Lens" which portrayed how Radiographers and Clinical Technologists practise as team of NMT's; and "Confirmation of Professional Self" which presented how individuals view their professional status. CONCLUSION: The study showed that the NMT role is highly specialised, multi-faceted and patient-centred. Their professional status is based on the nature of their role and their university level education and training. They work together under the umbrella title of NMT with a dual professional identity of "provider of care" and "user of science and technology". However, they may have an individual identity of Radiographer or Clinical Technologist that is determined by their training pathway. IMPLICATIONS FOR PRACTICE: This research has provided valuable understanding of the PI and RP of NMT's. By highlighting the differences in the regulatory status of this workforce, an insight into the future implications in the context of national healthcare planning has been provided, highlighting potentially significant issues that may impact on the manner in which NMT's can practice.


Assuntos
Medicina Nuclear , Humanos , Medicina Estatal , Pessoal Técnico de Saúde , Cintilografia , Percepção
3.
Phys Rev Lett ; 108(15): 151801, 2012 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-22587241

RESUMO

The decay B(s)(0) → J/ψK+ K- is investigated using 0.16 fb(-1) of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/ψϕ channel is well known, final states at higher K+ K- masses have not previously been studied. In the K+ K- mass spectrum we observe a significant signal in the f(2)'(1525) region as well as a nonresonant component. After subtracting the nonresonant component, we find B(B(s)(0) → J/ψf(2)'(1525))/B(B(s)(0) → J/ψϕ) = (26.4 ± 2.7 ± 2.4)%.

4.
Phys Rev Lett ; 108(11): 111602, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22540460

RESUMO

A search for time-integrated CP violation in D(0)→h(-)h(+) (h=K, π) decays is presented using 0.62 fb(-1) of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the slow pion in the D(*+)→D(0)π(+) and D(*-)→D[over ¯](0)π(-) decay chains. The difference in CP asymmetry between D(0)→K(-)K(+) and D(0)→π(-)π(+), ΔA(CP)≡A(CP)(K(-)K(+))-A(CP)(π(-)π(+)), is measured to be [-0.82±0.21(stat)±0.11(syst)]%. This differs from the hypothesis of CP conservation by 3.5 standard deviations.

5.
Phys Rev Lett ; 108(24): 241801, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-23004259

RESUMO

The interference between the K+ K- S-wave and P-wave amplitudes in B(s)(0) → J/ψK+ K- decays with the K+ K- pairs in the region around the ϕ(1020) resonance is used to determine the variation of the difference of the strong phase between these amplitudes as a function of K+ K- invariant mass. Combined with the results from our CP asymmetry measurement in B(s)(0) → J/ψϕ decays, we conclude that the B(s)(0) mass eigenstate that is almost CP = +1 is lighter and decays faster than the mass eigenstate that is almost CP = -1. This determines the sign of the decay width difference ΔΓ(s) ≡ Γ(L) - Γ(H) to be positive. Our result also resolves the ambiguity in the past measurements of the CP violating phase ϕ(s) to be close to zero rather than π. These conclusions are in agreement with the standard model expectations.

6.
Phys Rev Lett ; 108(10): 101601, 2012 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-22463398

RESUMO

A search is performed for the lepton number violating decay B+ → h- µ+ µ+, where h- represents a K- or a π-, using an integrated luminosity of 36 pb(-1) of data collected with the LHCb detector. The decay is forbidden in the standard model but allowed in models with a Majorana neutrino. No signal is observed in either channel and limits of B(B+ → K- µ+ µ+) < 5.4×10(-8) and B(B+ → π- µ+ µ+) < 5.8×10(-8) are set at the 95% confidence level. These improve the previous best limits by factors of 40 and 30, respectively.

7.
Phys Rev Lett ; 108(10): 101803, 2012 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-22463401

RESUMO

We present a measurement of the time-dependent CP-violating asymmetry in B(s)(0) → J/ψϕ decays, using data collected with the LHCb detector at the LHC. The decay time distribution of B(s)(0) → J/ψϕ is characterized by the decay widths Γ(H) and Γ(L) of the heavy and light mass eigenstates, respectively, of the B(s)(0) - B(s)(0) system and by a CP-violating phase ϕ(s). In a sample of about 8500 B(s)(0) → J/ψϕ events isolated from 0.37 fb(-1) of pp collisions at sqrt[s] = 7 TeV, we measure ϕ(s) = 0.15 ± 0.18(stat) ± 0.06(syst) rad. We also find an average B(s)(0) decay width Γ(s) ≡ (Γ(L) + Γ(H))/2 = 0.657 ± 0.009(stat) ± 0.008(syst) ps(-1) and a decay width difference ΔΓ(s) ≡ Γ(L) - Γ(H) = 0.123 ± 0.029(stat) ± 0.011(syst) ps(-1). Our measurement is insensitive to the transformation (ϕ(s),ΔΓ(s)) ↦ (π - ϕ(s), -ΔΓ(s)).

8.
Phys Rev Lett ; 108(16): 161801, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22680708

RESUMO

First observations of the Cabibbo-suppressed decays B(0) → D(+)K(-)π(+)π(-) and B(-) → D(0)K(-)π(+)π(-) are reported using 35 pb(-1) of data collected with the LHCb detector. Their branching fractions are measured with respect to the corresponding Cabibbo-favored decays, from which we obtain B(B(0) → D(+)K(-)π(+)π(-))/B(B(0) → D(+)π(-)π(+)π(-))=(5.9±1.1±0.5)×10(-2) and B(B(-) → D(0)K(-)π(+)π(-))/B(B(-) → D(0)π(-)π(+)π(-))=(9.4±1.3±0.9)×10(-2), where the uncertainties are statistical and systematic, respectively. The B(-) → D(0)K(-)π(+)π(-) decay is particularly interesting, as it can be used in a similar way to B(-) → D(0)K(-) to measure the Cabibbo-Kobayashi-Maskawa phase γ.

9.
Phys Rev Lett ; 108(18): 181806, 2012 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-22681061

RESUMO

The angular distributions and the partial branching fraction of the decay B0 → K*0 µ+ µ- are studied by using an integrated luminosity of 0.37 fb(-1) of data collected with the LHCb detector. The forward-backward asymmetry of the muons, A(FB), the fraction of longitudinal polarization, F(L), and the partial branching fraction dB/dq2 are determined as a function of the dimuon invariant mass. The measurements are in good agreement with the standard model predictions and are the most precise to date. In the dimuon invariant mass squared range 1.00-6.00 GeV2/c4, the results are A(FB)=-0.06(-0.14)(+0.13)±0.04, F(L)=0.55±0.10±0.03, and dB/dq2=(0.42±0.06±0.03)×10(-7) c4/GeV2. In each case, the first error is statistical and the second systematic.

10.
Phys Rev Lett ; 107(21): 211801, 2011 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-22181871

RESUMO

The relative abundance of the three decay modes B(0)→D(-)K(+), B(0)→D(-)π(+), and B(s)(0)→D(s)(-)π(+) produced in 7 TeV pp collisions at the LHC is determined from data corresponding to an integrated luminosity of 35 pb(-1). The branching fraction of B(0)→D(-)K(+) is found to be B(B(0)→D(-)K(+)) = (2.01 ± 0.18(stat) ± 0.14(syst)) × 10(-4). The ratio of fragmentation fractions f(s)/f(d) is determined through the relative abundance of B(s)(0)→D(s)(-)π(+) to B(0)→D(-)K(+) and B(0)→D(-)π(+), leading to f(s)/f(d) = 0.253 ± 0.017 ± 0.017 ± 0.020, where the uncertainties are statistical, systematic, and theoretical, respectively.

11.
Cancer Res ; 49(13): 3656-61, 1989 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-2659166

RESUMO

In an attempt to generate antibodies which recognize novel tumor-associated antigens we have immunized Rhesus monkeys (Macaca mulatta) with human colon carcinoma cells prepared from freshly excised tumors. Immunohistochemical characterization of polyclonal antisera from one monkey (DF6) revealed preferential reactivity with primary and metastatic colon carcinoma tissue, and a general lack of recognition of nonneoplastic mucosa. Immunoreactivity was localized to the luminal contents of glandular structures and to the apical surfaces of cells lining these glands. Immunoreactivity was not observed with any normal tissue examined. Examination of neoplastic tissues revealed reactivity with two gastric carcinoma specimens (n = 2) and one breast carcinoma (n = 7). In reactive colon carcinoma tissues, the pattern of staining with DF6 was similar to that of several other antibodies including anti-carcinoembryonic antigen, B72.3, anti-Le(x) and anti-Le(y). However, the panel of tissues recognized by these antibodies and DF6 differed significantly, suggesting that the DF6-reactive epitopes are unique. Human colon carcinoma cell lines maintained in vitro also expressed antigens recognized by DF6 in a pattern similar to that of surgically excised tissue. This preliminary characterization of DF6 antiserum suggests that immunization of Rhesus monkeys is a potentially useful protocol for identifying antigens preferentially expressed by human colon carcinoma.


Assuntos
Anticorpos Antineoplásicos/imunologia , Antígenos de Neoplasias/imunologia , Carcinoma/imunologia , Neoplasias do Colo/imunologia , Animais , Antígeno Carcinoembrionário/imunologia , Reações Cruzadas , Imunofluorescência , Humanos , Macaca mulatta , Células Tumorais Cultivadas/imunologia
12.
Biochim Biophys Acta ; 861(1): 197-200, 1986 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-3756153

RESUMO

An intrinsic membrane glycoprotein, Mr 131 000, is a major developmentally specific component of the neonatal guinea-pig small intestinal microvillar membrane. Such high-molecular-weight proteins are often difficult to translate in vitro. In this study we report a successful strategy for the identification of the primary translation product of this glycoprotein, a high-molecular-weight precursor polypeptide of approximate Mr 225 000.


Assuntos
Intestino Delgado/ultraestrutura , Biossíntese Peptídica , Animais , Sistema Livre de Células , Eletroforese em Gel de Poliacrilamida , Cobaias , Microvilosidades/metabolismo , Peso Molecular , Biossíntese de Proteínas
13.
Biochim Biophys Acta ; 815(2): 175-83, 1985 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-3995021

RESUMO

The adult guinea-pig small intestinal microvillus membrane was purified approximately 25-fold by both cation-precipitation and differential centrifugation methods. Comparison by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed no substantial differences in polypeptide composition between the two preparations. One-dimensional SDS-PAGE and two-dimensional isoelectric focussing (IEF)/SDS-PAGE, together with Coomassie-blue, silver and lectin-staining, showed three major high molecular weight polypeptides, Mr 108 000, 116 000 and 127 000, as well as a 47 kDa protein (actin), as major constituents of the membrane. The proteins of Mr 108 000 and 116 000 were strongly concanavalin A reactive. A detailed two-dimensional IEF/SDS-PAGE map of the membrane was constructed. Sodium carbonate treatment showed the two concanavalin A-reactive glycoproteins, Mr 108 000 and 116 000, comprising the sucrase-isomaltase complex, to be loosely-associated 'extrinsic' microvillus membrane proteins. Two proteins, Mr 127 000 and 135 000, were tightly-associated 'intrinsic' microvillus proteins. Despite regional differences in specific activity of some small intestinal microvillar enzymes, most noticeably enterokinase (EC 3.4.21.9) and dipeptidyl peptidase IV (EC 3.4.14.x), no substantial regional differences were seen in microvillus membrane polypeptide composition. In contrast, a substantial increase in the major high molecular weight proteins of Mr 108 000 and 116 000 accompanied a 10-fold rise in sucrase-isomaltase activity, and loss of a major protein of Mr 131 000 accompanied the complete loss of lactase activity from the membrane during postnatal development.


Assuntos
Mucosa Intestinal/análise , Proteínas de Membrana/análise , Microvilosidades/análise , Fatores Etários , Animais , Fracionamento Celular/métodos , Membrana Celular/análise , Membrana Celular/enzimologia , Cobaias , Mucosa Intestinal/enzimologia , Mucosa Intestinal/crescimento & desenvolvimento , Ponto Isoelétrico , Microvilosidades/enzimologia , Peso Molecular
14.
Curr Opin Biotechnol ; 9(6): 595-601, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9889141

RESUMO

New technologies in both combinatorial chemistry and combinatorial biology promise to unlock new opportunities for drug discovery and lead optimisation. Using such genome-based technologies to measure the dynamic properties of pharmacological systems, pharmacogenomics can now provide an objective measure of a drug's biological efficacy, including its potential adverse effects.


Assuntos
DNA/genética , Tratamento Farmacológico , Genoma , Farmacogenética , Animais , Biotecnologia , DNA/química , Bases de Dados como Assunto , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Variação Genética , Humanos , Polimorfismo Genético
15.
Trends Biotechnol ; 19(8): 288-92, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11451470

RESUMO

The demands on drug discovery organizations have increased dramatically in recent years, partly because of the need to identify novel targets that are both relevant to disease and chemically tractable. This is leading to an industrial approach to traditional biology and chemistry, inspired in part by the revolution in genomics. The purpose of this article is to highlight the flow of investigation from gene sequence of potential therapeutic targets, through mRNA and protein expression, to protein structure and drug design. To deal with this scale of activity, many commercial and public organizations have been established and some of the key players will be listed in this article.


Assuntos
Desenho de Fármacos , Genoma , Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Farmacogenética , Proteínas/genética , Proteoma , RNA Mensageiro/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-18267695

RESUMO

The results of phase noise measurement for high-overtone bulk-acoustic resonators (HBARs) for use in high-performance oscillators, operating at 640 MHz with insertion losses of 10-15 dB and unmatched Qs greater than 110 K are reported. Noise measurements made on these resonators with input drive levels of 16 dBm have shown self-noise levels of S(y)(f=100 Hz)=8.0x10(-26) for 1/f noise which represents state-of-the-art for a UHF resonator.

17.
Eur Phys J C Part Fields ; 72(6): 2022, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-25814835

RESUMO

The calibration and performance of the opposite-side flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B+→J/ψK+, B0→J/ψK∗0 and B0→D∗-µ+νµ decay modes with 0.37 fb-1 of data collected in pp collisions at [Formula: see text] during the 2011 physics run. The opposite-side tagging power is determined in the B+→J/ψK+ channel to be (2.10±0.08±0.24) %, where the first uncertainty is statistical and the second is systematic.

18.
Eur Phys J C Part Fields ; 72(6): 2025, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-25814836

RESUMO

The production of ϒ(1S), ϒ(2S) and ϒ(3S) mesons in proton-proton collisions at the centre-of-mass energy of [Formula: see text] is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The ϒ mesons are reconstructed in the decay mode ϒ→µ+µ- and the signal yields are extracted from a fit to the µ+µ- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the ϒ transverse momentum pT and rapidity y, over the range pT <15 GeV/c and 2.0

19.
Eur Phys J C Part Fields ; 72(8): 2100, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-25814845

RESUMO

The differential cross-section for the inclusive production of ψ(2S) mesons in pp collisions at [Formula: see text] has been measured with the LHCb detector. The data sample corresponds to an integrated luminosity of 36 pb-1. The ψ(2S) mesons are reconstructed in the decay channels ψ(2S)→µ+µ- and ψ(2S)→J/ψπ+π-, with the J/ψ meson decaying into two muons. Results are presented both for promptly produced ψ(2S) mesons and for those originating from b-hadron decays. In the kinematic range pT(ψ(2S))≤16 GeV/c and 2

20.
J Pediatr Gastroenterol Nutr ; 6(3): 445-53, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3430251

RESUMO

The effect of intrapharyngeal infusion and subsequent passage of the lectin concanavalin A through the gastrointestinal tract of neonatal guinea pigs was examined. The lectin, administered at a concentration of 1 mg/ml, caused considerable mucosal damage in the stomach. Subsequent passage of the lectin through the small intestine caused little cellular damage to the mucosa, as judged by light and electron microscopy. Parallel morphometric analyses of the jejunum showed a decrease in mean villus height and an increase in mean crypt depth of 8% after 5 h of lectin administration. A 4.7-fold increase in jejunal crypt cell production rate was observed, accompanied by a statistically significant increase in the number of intraepithelial lymphocytes. These morphologic and kinetic changes were accompanied by a three-fold increase in the urinary lactulose:mannitol excretion ratio, indicative of a loss of mucosal integrity. No systemic antibody response to concanavalin A was demonstrated within 5 h of intragastric infusion of the lectin. Concanavalin A, conjugated with 10 nm colloidal gold particles, was also directly infused into the lumen of the jejunum in vivo. Within 60 min, both villous and crypt epithelial cells contained gold particles, demonstrating the rapid accessibility of crypt cells to the lectin. Intercellular spaces appeared within the villous epithelium, although both junctional complexes and spot desmosomes were retained. The brush border was abnormal with signs of incipient vesicularization. These findings have implications for our understanding of the pathogenesis of childhood coeliac disease and for the vulnerability of the neonatal gut to food proteins.


Assuntos
Concanavalina A/farmacologia , Absorção Intestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Concanavalina A/metabolismo , Epitélio/efeitos dos fármacos , Cobaias , Microscopia Eletrônica , Receptores de Concanavalina A/metabolismo
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