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1.
Br J Cancer ; 125(11): 1462-1465, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34316019

RESUMEN

The National Cancer Imaging Translational Accelerator (NCITA) is creating a UK national coordinated infrastructure for accelerated translation of imaging biomarkers for clinical use. Through the development of standardised protocols, data integration tools and ongoing training programmes, NCITA provides a unique scalable infrastructure for imaging biomarker qualification using multicentre clinical studies.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Pruebas Diagnósticas de Rutina/métodos , Neoplasias/diagnóstico por imagen , Humanos , Proyectos de Investigación , Reino Unido
2.
Nature ; 482(7383): 59-62, 2012 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-22278059

RESUMEN

Matter with a high energy density (>10(5) joules per cm(3)) is prevalent throughout the Universe, being present in all types of stars and towards the centre of the giant planets; it is also relevant for inertial confinement fusion. Its thermodynamic and transport properties are challenging to measure, requiring the creation of sufficiently long-lived samples at homogeneous temperatures and densities. With the advent of the Linac Coherent Light Source (LCLS) X-ray laser, high-intensity radiation (>10(17) watts per cm(2), previously the domain of optical lasers) can be produced at X-ray wavelengths. The interaction of single atoms with such intense X-rays has recently been investigated. An understanding of the contrasting case of intense X-ray interaction with dense systems is important from a fundamental viewpoint and for applications. Here we report the experimental creation of a solid-density plasma at temperatures in excess of 10(6) kelvin on inertial-confinement timescales using an X-ray free-electron laser. We discuss the pertinent physics of the intense X-ray-matter interactions, and illustrate the importance of electron-ion collisions. Detailed simulations of the interaction process conducted with a radiative-collisional code show good qualitative agreement with the experimental results. We obtain insights into the evolution of the charge state distribution of the system, the electron density and temperature, and the timescales of collisional processes. Our results should inform future high-intensity X-ray experiments involving dense samples, such as X-ray diffractive imaging of biological systems, material science investigations, and the study of matter in extreme conditions.

3.
Phys Rev Lett ; 117(2): 027401, 2016 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-27447522

RESUMEN

X-ray diffractive imaging with laterally coherent x-ray free-electron laser (XFEL) pulses is increasingly utilized to obtain ultrafast snapshots of matter. Here we report the amazing disappearance of single-shot charge and magnetic diffraction patterns recorded with resonantly tuned, narrow bandwidth XFEL pulses. Our experimental results reveal the exquisite sensitivity of single-shot charge and magnetic diffraction patterns of a magnetic film to the onset of field-induced stimulated elastic x-ray forward scattering. The loss in diffraction contrast, measured over 3 orders of magnitude in intensity, is in remarkable quantitative agreement with a recent theory that is extended to include diffraction.

4.
Nat Mater ; 12(4): 293-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23503010

RESUMEN

Ultrafast laser techniques have revealed extraordinary spin dynamics in magnetic materials that equilibrium descriptions of magnetism cannot explain. Particularly important for future applications is understanding non-equilibrium spin dynamics following laser excitation on the nanoscale, yet the limited spatial resolution of optical laser techniques has impeded such nanoscale studies. Here we present ultrafast diffraction experiments with an X-ray laser that probes the nanoscale spin dynamics following optical laser excitation in the ferrimagnetic alloy GdFeCo, which exhibits macroscopic all-optical switching. Our study reveals that GdFeCo displays nanoscale chemical and magnetic inhomogeneities that affect the spin dynamics. In particular, we observe Gd spin reversal in Gd-rich nanoregions within the first picosecond driven by the non-local transfer of angular momentum from larger adjacent Fe-rich nanoregions. These results suggest that a magnetic material's microstructure can be engineered to control transient laser-excited spins, potentially allowing faster (~ 1 ps) spin reversal than in present technologies.

5.
Phys Rev Lett ; 109(24): 245003, 2012 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-23368333

RESUMEN

The x-ray intensities made available by x-ray free electron lasers (FEL) open up new x-ray matter interaction channels not accessible with previous sources. We report here on the resonant generation of Kα emission, that is to say the production of copious Kα radiation by tuning the x-ray FEL pulse to photon energies below that of the K edge of a solid aluminum sample. The sequential absorption of multiple photons in the same atom during the 80 fs pulse, with photons creating L-shell holes and then one resonantly exciting a K-shell electron into one of these holes, opens up a channel for the Kα production, as well as the absorption of further photons. We demonstrate rich spectra of such channels, and investigate the emission produced by tuning the FEL energy to the K-L transitions of those highly charged ions that have transition energies below the K edge of the cold material. The spectra are sensitive to x-ray intensity dependent opacity effects, with ions containing L-shell holes readily reabsorbing the Kα radiation.

6.
Phys Rev Lett ; 109(6): 065002, 2012 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-23006275

RESUMEN

We have used the Linac Coherent Light Source to generate solid-density aluminum plasmas at temperatures of up to 180 eV. By varying the photon energy of the x rays that both create and probe the plasma, and observing the K-α fluorescence, we can directly measure the position of the K edge of the highly charged ions within the system. The results are found to disagree with the predictions of the extensively used Stewart-Pyatt model, but are consistent with the earlier model of Ecker and Kröll, which predicts significantly greater depression of the ionization potential.

7.
Phys Rev Lett ; 107(14): 144801, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-22107200

RESUMEN

Measurements of the spatial and temporal coherence of single, femtosecond x-ray pulses generated by the first hard x-ray free-electron laser, the Linac Coherent Light Source, are presented. Single-shot measurements were performed at 780 eV x-ray photon energy using apertures containing double pinholes in "diffract-and-destroy" mode. We determined a coherence length of 17 µm in the vertical direction, which is approximately the size of the focused Linac Coherent Light Source beam in the same direction. The analysis of the diffraction patterns produced by the pinholes with the largest separation yields an estimate of the temporal coherence time of 0.55 fs. We find that the total degree of transverse coherence is 56% and that the x-ray pulses are adequately described by two transverse coherent modes in each direction. This leads us to the conclusion that 78% of the total power is contained in the dominant mode.

8.
PLoS One ; 15(12): e0243369, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33347451

RESUMEN

After the Battle Dunbar between English and Scottish forces in 1650, captured Scottish soldiers were imprisoned in Durham and many hundreds died there within a few weeks. The partial skeletal remains of 28 of these men were discovered in 2013. Building on previous osteological work, here we report wide-ranging scientific studies of the remains to address the following questions: Did they have comparable diet, health and disease throughout their lives? Did they have common histories of movement (or lack of movement) during their childhoods? Can we create a collective biography of these men? Strontium and oxygen isotope analysis of tooth enamel investigated childhood movement. Carbon and nitrogen isotope analysis of incrementally sampled dentine addressed childhood diet and nutrition. Metaproteomic analysis of dental calculus investigated oral microbiomes and food residues; this was complemented by microscopic analysis of debris in calculus from ingested materials. Selected individuals were examined for dental microwear. The extent of hydroxylation of proline in collagen was examined as a potential biomarker for scurvy. An osteobiography for each man was created using the full range of data generated about him, and these were synthesised using an approach based on the historical method for a collective biography or prosopography. The childhood residences of the men were primarily within the Midland Valley of Scotland, though some spent parts of their childhood outside the British Isles. This is concordant with the known recruitment areas of the Scottish army in 1650. Their diets included oats, brassicas and milk but little seafood, as expected for lowland rather than highland diets of the period. Childhood periods of starvation or illness were almost ubiquitous, but not simultaneous, suggesting regionally variable food shortages in the 1620s and 1630s. It is likely there was widespread low-level scurvy, ameliorating in later years of life, which suggests historically unrecorded shortages of fruit and vegetables in the early 1640s. Almost all men were exposed to burnt plant matter, probably as inhaled soot, and this may relate to the high proportion of them with of sinusitis. Interpersonal violence causing skeletal trauma was rare. Based on commonalities in their osteobiographies, we argue that these men were drawn from the same stratum of society. This study is perhaps the most extensive to date of individuals from 17th century Scotland. Combined with a precise historical context it allows the lives of these men to be investigated and compared to the historical record with unprecedented precision. It illustrates the power of archaeological science methods to confirm, challenge and complement historical evidence.


Asunto(s)
Esmalte Dental/metabolismo , Dieta/historia , Ingestión de Energía , Personal Militar , Escorbuto/metabolismo , Arqueología , Historia del Siglo XVII , Humanos , Masculino , Escocia , Escorbuto/historia , Escorbuto/patología
9.
Science ; 167(3924): 1506-8, 1970 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-5461172

RESUMEN

Mouse embryos in the stage of development prior to implantation were cultured in vitro in a medium that contained radioactive bicarbonate. The radioactivity was incorporated into the proteins and nucleic acids that were acid soluble. Uptake of radioactivity occurred into protein in the unfertilized ovum and was highest in all fractions in the early blastocyst stage. No incorporation was detected in the lipid fraction.


Asunto(s)
Dióxido de Carbono/metabolismo , Diferenciación Celular , Embrión de Mamíferos/metabolismo , Animales , Isótopos de Carbono , Técnicas de Cultivo , Femenino , Edad Gestacional , Ratones , Óvulo/metabolismo
10.
Science ; 230(4727): 827-9, 1985 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-3904001

RESUMEN

Substantial evidence suggests that calcium has a pivotal role in regulating the initial events through which insulin alters plasma membrane metabolism. Because binding of insulin to its receptor represents the initial site of insulin action in the plasma membrane, studies were undertaken to determine whether the insulin receptor is a calmodulin-binding protein. Preparations enriched in the insulin receptor and calmodulin-binding proteins were isolated from detergent-solubilized rat adipocyte membranes by chromatography with wheat germ agglutinin agarose and calmodulin-conjugated Sepharose, respectively. Substantial purification of a manganese-dependent, insulin-sensitive phosphoprotein of 95K identified as the beta subunit of the insulin receptor was accomplished. Binding and photocovalent cross-linking of iodine-125-labeled calmodulin to these affinity-purified preparations and to isolated plasma membranes, followed by immunoadsorption with insulin receptor antibodies bound to protein A Sepharose, resulted in significant purification of a binding complex of 110K to 140K. These results indicate that the adipocyte insulin receptor or a polypeptide closely associated with the receptor is a calmodulin-binding protein.


Asunto(s)
Proteínas de Unión a Calmodulina/metabolismo , Receptor de Insulina/metabolismo , Tejido Adiposo/citología , Animales , Calmodulina/metabolismo , Proteínas de Unión a Calmodulina/aislamiento & purificación , Membrana Celular/metabolismo , Insulina/metabolismo , Fosforilación , Ratas , Receptor de Insulina/aislamiento & purificación
12.
Nat Commun ; 10(1): 1756, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30988403

RESUMEN

Sub-picosecond magnetisation manipulation via femtosecond optical pumping has attracted wide attention ever since its original discovery in 1996. However, the spatial evolution of the magnetisation is not yet well understood, in part due to the difficulty in experimentally probing such rapid dynamics. Here, we find evidence of a universal rapid magnetic order recovery in ferrimagnets with perpendicular magnetic anisotropy via nonlinear magnon processes. We identify magnon localisation and coalescence processes, whereby localised magnetic textures nucleate and subsequently interact and grow in accordance with a power law formalism. A hydrodynamic representation of the numerical simulations indicates that the appearance of noncollinear magnetisation via optical pumping establishes exchange-mediated spin currents with an equivalent 100% spin polarised charge current density of 107 A cm-2. Such large spin currents precipitate rapid recovery of magnetic order after optical pumping. The magnon processes discussed here provide new insights for the stabilization of desired meta-stable states.

13.
Am J Med Qual ; 32(5): 547-551, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27582459

RESUMEN

Health care information technology (IT) outages pose a threat to patient safety and patient care continuity. Organizations' downtime plans must be updated regularly and staff at the work area level should have experience with implementing IT outage operations through downtime drills. This article describes the study institution's IT Outage Toolkit, based on the acronym CLEAR, which guides the development of a downtime plan as well as design, execution, and assessment of work area downtime drills. Self-report and external audits of downtime drills help identify performance gaps and gaps in downtime plans.


Asunto(s)
Informática Médica , Seguridad del Paciente , Continuidad de la Atención al Paciente , Humanos
14.
Biogeochemistry ; 135(1): 49-67, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-32009691

RESUMEN

Shelf sediments underlying temperate and oxic waters of the Celtic Sea (NW European Shelf) were found to have shallow oxygen penetrations depths from late spring to late summer (2.2-5.8 mm below seafloor) with the shallowest during/after the spring-bloom (mid-April to mid-May) when the organic carbon content was highest. Sediment porewater dissolved iron (dFe, <0.15 µm) mainly (>85%) consisted of Fe(II) and gradually increased from 0.4 to 15 µM at the sediment surface to ~100-170 µM at about 6 cm depth. During the late spring this Fe(II) was found to be mainly present as soluble Fe(II) (>85% sFe, <0.02 µm). Sub-surface dFe(II) maxima were enriched in light isotopes (δ56Fe -2.0 to -1.5‰), which is attributed to dissimilatory iron reduction (DIR) during the bacterial decomposition of organic matter. As porewater Fe(II) was oxidised to insoluble Fe(III) in the surface sediment layer, residual Fe(II) was further enriched in light isotopes (down to -3.0‰). Ferrozine-reactive Fe(II) was found in surface porewaters and in overlying core top waters, and was highest in the late spring period. Shipboard experiments showed that depletion of bottom water oxygen in late spring can lead to a substantial release of Fe(II). Reoxygenation of bottom water caused this Fe(II) to be rapidly lost from solution, but residual dFe(II) and dFe(III) remained (12 and 33 nM) after >7 h. Iron(II) oxidation experiments in core top and bottom waters also showed removal from solution but at rates up to 5-times slower than predicted from theoretical reaction kinetics. These data imply the presence of ligands capable of complexing Fe(II) and supressing oxidation. The lower oxidation rate allows more time for the diffusion of Fe(II) from the sediments into the overlying water column. Modelling indicates significant diffusive fluxes of Fe(II) (on the order of 23-31 µmol m-2 day-1) are possible during late spring when oxygen penetration depths are shallow, and pore water Fe(II) concentrations are highest. In the water column this stabilised Fe(II) will gradually be oxidised and become part of the dFe(III) pool. Thus oxic continental shelves can supply dFe to the water column, which is enhanced during a small period of the year after phytoplankton bloom events when organic matter is transferred to the seafloor. This input is based on conservative assumptions for solute exchange (diffusion-reaction), whereas (bio)physical advection and resuspension events are likely to accelerate these solute exchanges in shelf-seas.

15.
Biochim Biophys Acta ; 685(1): 27-31, 1982 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-6977376

RESUMEN

The carbocyanine dye, diS-C3-(5) was used to quantitate the plasma membrane potential of the bullfrog corneal endothelium. It was shown that valinomycin hyperpolarized the endothelial cell and that in the presence of the ionophore the membrane potential largely reflected the K+ equilibrium potential. Using calibration curves constructed by changing medium K+ concentration in the presence of valinomycin, and nigericin and ouabain to abolish ion gradients and electrogenic pump activity, the cell membrane potential was calculated to be 28.6 +/- 4.2 mV. The major source of this potential was a K+ diffusion potential, and the membrane Na+ conductance reduced the cell potential to less than the apparent K+ equilibrium potential of 51.5 +/- 5.1 mV. About 20% of the cell potential could be ascribed to the rheogenic (Na+ + K+)-ATPase.


Asunto(s)
Córnea/fisiología , Animales , Carbocianinas , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Cloruros/farmacología , Endotelio/fisiología , Potenciales de la Membrana/efectos de los fármacos , Nigericina/farmacología , Ouabaína/farmacología , Potasio/farmacología , Rana catesbeiana , Sodio/farmacología , Valinomicina/farmacología
16.
Biochim Biophys Acta ; 389(3): 550-6, 1975 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-1079144

RESUMEN

Corneas of bullfrog (Rana catesbeiana) were mounted between lucite chambers. A four-electrode system was used and the potential difference (PD) and the electrical resistance were measured. In intact corneas, the PD averaged 25 mV (acqueous side positive) and the electrical resistance 1.5 kQ - cm2. perfusion of the aqueous side with high K+ solutions resulted in a marked decrease in PD and a drop in the electrical resistance. Scraping the epithelium (leaving the stroma plus endothelium) resulted in a drop of the PD to about zero and a decrease in electrical resistance to about 0.1 kQ - CM2 and a very small PD response to a marked elevation of the K+ concentration on the aqueous side. On the basis of the above, it is obvious that the large delta PD in intact corneas, due to elevation of the K+ concentration, must be due to K+ diffusing from the aqueous side across the endothelium and stroma and reaching the epithelium. The duration of the PD response is therefore a measure of the resistance to diffusion of the stroma plus endothelium. A quantitiative analysis shows that under in vitro conditions the resistance of the endothelium plus stroma to the diffusion of ions is very low.


Asunto(s)
Córnea/fisiología , Potasio/farmacología , Animales , Córnea/efectos de los fármacos , Estimulación Eléctrica , Endotelio/efectos de los fármacos , Endotelio/fisiología , Cinética , Matemática , Potenciales de la Membrana/efectos de los fármacos , Rana catesbeiana , Factores de Tiempo
17.
Br J Radiol ; 78(934): 952-3, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16177021

RESUMEN

Intrauterine devices (IUDs) have been used worldwide for contraception for decades. They are easily deployed, inexpensive and one of the most reliable contraceptive methods. Though ease of placement is such that they are frequently placed by midwives in the outpatient setting in developing countries, some complications due to its misplacement occasionally can occur. We present two cases with unknown uterine septum in which IUDs were placed without prior ultrasound examination of the pelvis. We conclude evaluation of the pelvis by ultrasound prior to placement of IUDs in women with a history of breech presentation, preterm labour, or recurrent miscarriage may be helpful in identifying uterine anomalies that make IUD placement unsuitable.


Asunto(s)
Dispositivos Intrauterinos , Útero/anomalías , Aborto Habitual/etiología , Adulto , Presentación de Nalgas , Cesárea , Contraindicaciones , Femenino , Humanos , Embarazo , Ultrasonografía , Útero/diagnóstico por imagen
18.
Cell Calcium ; 6(6): 491-501, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3937599

RESUMEN

The effects of Ca2+ and calmodulin on endogenously catalyzed ADP-ribosylation were investigated in adipocyte plasma membranes. Four specific proteins of 70, 65, 61 and 52 kDa were labeled with [32P]ADP-ribose and ADP-ribosylation of the proteins was highly dependent upon the conditions employed. ADP-ribosylation of the 70 kDa protein was observed only in membranes supplemented with Ca2+. Maximal incorporation of [32P] into the protein was achieved with free Ca2+ concentrations of 90 microM. Calcium-stimulated ADP-ribosylation of the 70 kDa protein was inhibited by calmodulin. Half-maximal inhibition was observed in membranes incubated with 1.2 microM calmodulin. The effect of calmodulin was characterized by an inhibition of the incorporation of [32P]ADP-ribose as opposed to a stimulation of its removal. ADP-ribosylation of the 61 kDa protein was not altered by added Ca2+ and/or calmodulin whereas ADP-ribosylation of the 65 kDa protein was partially (50%) inhibited by free Ca2+ concentrations between 10(-6) - 10(-5) M. These results provide evidence that the adipocyte plasma membrane contains ADP-ribosyltransferase activities and demonstrate that ADP-ribosylation of a 70 kDa protein is regulated by Ca2+ and calmodulin.


Asunto(s)
Adenosina Difosfato Ribosa/metabolismo , Tejido Adiposo/metabolismo , Calcio/farmacología , Calmodulina/farmacología , Proteínas de la Membrana/metabolismo , Azúcares de Nucleósido Difosfato/metabolismo , Tejido Adiposo/efectos de los fármacos , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Ácido Edético/farmacología , Electroforesis en Gel de Poliacrilamida , Cinética , Proteínas de la Membrana/aislamiento & purificación , Peso Molecular , Ratas
19.
Cancer Treat Rev ; 26(2): 91-102, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10772967

RESUMEN

Elevation of established blood tumour markers correlates with the stage of breast cancer. The major role of current blood markers is therefore in the diagnosis and monitoring of metastatic disease. A combination of markers is better than a single marker with the most widely adopted combination being CEA and one MUC1 mucin, commonly detected as either CA15.3 or CA27.29. Tumour marker measurement is now used as a complementary test in the diagnosis of symptomatic metastases. In the monitoring of therapeutic response to both endocrine and cytotoxic therapies in advanced disease, biochemical assessment using blood markers not only correlates with conventional UICC criteria but has a lot of advantages which make it a potentially superior way of assessment. In this regard, CA15.3, CEA and ESR are the best validated combination. Studies are ongoing to evaluate the use of sequential blood tumour marker measurements in the follow-up of patients after treatment for their primary breast cancer, in terms of both early detection and early therapeutic intervention. Further randomized studies are also required to ascertain that marker-directed therapy is superior to the current practice for metastatic disease. In line with clinical studies, intensive laboratory work is being carried out to optimize the use of blood markers in advanced disease as well as to exploit their use in screening and diagnosis of early primary breast cancer.


Asunto(s)
Biomarcadores de Tumor/sangre , Neoplasias de la Mama/diagnóstico , Antígeno Carcinoembrionario/sangre , Ensayos Clínicos como Asunto , Humanos , Mucina-1/sangre , Metástasis de la Neoplasia , Sensibilidad y Especificidad
20.
J Natl Cancer Inst Monogr ; (14): 165-9, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8123354

RESUMEN

Cancer incidence and mortality are disproportionately high in older adults, yet most public service campaigns have not been directed explicitly at this population. We analyzed Cancer Information Service (CIS) call data from the years 1983-1990 to characterize callers age 60 years and over. Of 1,091,809 calls from which the age of the caller was ascertained, 206,104 (19%) were from this age group. Most older callers learned of the CIS from the telephone book, television, and brochures or pamphlets. In addition, we examined calls specifically from 1990 to ascertain recent trends in CIS utilization. Comparisons also were made between callers 60 and older and those 40-59. Additional targeting could increase calls from older adults.


Asunto(s)
Servicios de Información , Oncología Médica/educación , Adulto , Factores de Edad , Anciano , Humanos , Persona de Mediana Edad
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