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1.
Nat Commun ; 15(1): 2975, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582938

RESUMO

Indirect Drive Inertial Confinement Fusion Experiments on the National Ignition Facility (NIF) have achieved a burning plasma state with neutron yields exceeding 170 kJ, roughly 3 times the prior record and a necessary stage for igniting plasmas. The results are achieved despite multiple sources of degradations that lead to high variability in performance. Results shown here, for the first time, include an empirical correction factor for mode-2 asymmetry in the burning plasma regime in addition to previously determined corrections for radiative mix and mode-1. Analysis shows that including these three corrections alone accounts for the measured fusion performance variability in the two highest performing experimental campaigns on the NIF to within error. Here we quantify the performance sensitivity to mode-2 symmetry in the burning plasma regime and apply the results, in the form of an empirical correction to a 1D performance model. Furthermore, we find the sensitivity to mode-2 determined through a series of integrated 2D radiation hydrodynamic simulations to be consistent with the experimentally determined sensitivity only when including alpha-heating.

2.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38236087

RESUMO

We present the development of an experimental platform that can collect four frames of x-ray diffraction data along a single line of sight during laser-driven, dynamic-compression experiments at the National Ignition Facility. The platform is comprised of a diagnostic imager built around ultrafast sensors with a 2-ns integration time, a custom target assembly that serves also to shield the imager, and a 10-ns duration, quasi-monochromatic x-ray source produced by laser-generated plasma. We demonstrate the performance with diffraction data for Pb ramp compressed to 150 GPa and illuminated by a Ge x-ray source that produces ∼7 × 1011, 10.25-keV photons/ns at the 400 µm diameter sample.

4.
Nature ; 601(7894): 542-548, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35082418

RESUMO

Obtaining a burning plasma is a critical step towards self-sustaining fusion energy1. A burning plasma is one in which the fusion reactions themselves are the primary source of heating in the plasma, which is necessary to sustain and propagate the burn, enabling high energy gain. After decades of fusion research, here we achieve a burning-plasma state in the laboratory. These experiments were conducted at the US National Ignition Facility, a laser facility delivering up to 1.9 megajoules of energy in pulses with peak powers up to 500 terawatts. We use the lasers to generate X-rays in a radiation cavity to indirectly drive a fuel-containing capsule via the X-ray ablation pressure, which results in the implosion process compressing and heating the fuel via mechanical work. The burning-plasma state was created using a strategy to increase the spatial scale of the capsule2,3 through two different implosion concepts4-7. These experiments show fusion self-heating in excess of the mechanical work injected into the implosions, satisfying several burning-plasma metrics3,8. Additionally, we describe a subset of experiments that appear to have crossed the static self-heating boundary, where fusion heating surpasses the energy losses from radiation and conduction. These results provide an opportunity to study α-particle-dominated plasmas and burning-plasma physics in the laboratory.

5.
Phys Rev Lett ; 126(2): 025002, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33512229

RESUMO

Inertial confinement fusion implosions must achieve high in-flight shell velocity, sufficient energy coupling between the hot spot and imploding shell, and high areal density (ρR=∫ρdr) at stagnation. Asymmetries in ρR degrade the coupling of shell kinetic energy to the hot spot and reduce the confinement of that energy. We present the first evidence that nonuniformity in the ablator shell thickness (∼0.5% of the total thickness) in high-density carbon experiments is a significant cause for observed 3D ρR asymmetries at the National Ignition Facility. These shell-thickness nonuniformities have significantly impacted some recent experiments leading to ρR asymmetries on the order of ∼25% of the average ρR and hot spot velocities of ∼100 km/s. This work reveals the origin of a significant implosion performance degradation in ignition experiments and places stringent new requirements on capsule thickness metrology and symmetry.

6.
Clin. transl. oncol. (Print) ; 19(6): 718-726, jun. 2017. tab, graf, ilus
Artigo em Inglês | IBECS | ID: ibc-162829

RESUMO

Purpose. Biomarkers, such as mutant RAS, predict resistance to anti-EGFR therapy in only a proportion of patients, and hence, other predictive biomarkers are needed. The aims were to identify candidate genes upregulated in colorectal cancer cell lines resistant to anti-EGFR monoclonal antibody treatment, to knockdown (KD) these genes in the resistant cell lines to determine if sensitivity to anti-EGFR antibody was restored, and finally to perform a pilot correlative study of EGR1 expression and outcomes in a cohort of metastatic colorectal cancer (mCRC) patients given cetuximab therapy. Methods. Comparative expression array analysis of resistant cell lines (SW48, COLO-320DM, and SNU-C1) vs sensitive cell lines (LIM1215, CaCo2, and SW948) was performed. The highest up-regulated gene in each resistant cell line was knocked down (KD) using RNA interference, and effect on proliferation was assessed with and without anti-EGFR treatment. Expression of the candidate genes in patients’ tumours treated with cetuximab was assessed by immunohistochemistry; survival analyses were performed comparing high vs low expression. Results. Genes significantly upregulated in resistant cell lines were EGR1 (early growth response protein 1), HBEGF (heparin-binding epidermal growth factor-like growth factor), and AKT3 (AKT serine/threonine kinase 3). KD of each gene resulted in the respective cells being more sensitive to anti-EGFR treatment, suggesting that the resistant phenotype was reversed. In the pilot study of mCRC patients treated with cetuximab, both median PFS (1.38 months vs 6.79 months; HR 2.77 95% CI 1.2-19.4) and median OS (2.59 months vs 9.82 months; HR 3.0 95% CI 1.3-23.2) were significantly worse for those patients with high EGR1 expression. Conclusion. High EGR1 expression may be a candidate biomarker of resistance to anti-EGFR therapy (AU)


No disponible


Assuntos
Resistencia a Medicamentos Antineoplásicos , Técnicas In Vitro , Cetuximab/uso terapêutico , Metástase Neoplásica/tratamento farmacológico , Expressão Gênica , Biomarcadores , Genes erbB-1 , Proteínas Oncogênicas v-erbB/análise , RNA/análise , Imuno-Histoquímica , Linhagem Celular
7.
Clin Transl Oncol ; 19(6): 718-726, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28005260

RESUMO

PURPOSE: Biomarkers, such as mutant RAS, predict resistance to anti-EGFR therapy in only a proportion of patients, and hence, other predictive biomarkers are needed. The aims were to identify candidate genes upregulated in colorectal cancer cell lines resistant to anti-EGFR monoclonal antibody treatment, to knockdown (KD) these genes in the resistant cell lines to determine if sensitivity to anti-EGFR antibody was restored, and finally to perform a pilot correlative study of EGR1 expression and outcomes in a cohort of metastatic colorectal cancer (mCRC) patients given cetuximab therapy. METHODS: Comparative expression array analysis of resistant cell lines (SW48, COLO-320DM, and SNU-C1) vs sensitive cell lines (LIM1215, CaCo2, and SW948) was performed. The highest up-regulated gene in each resistant cell line was knocked down (KD) using RNA interference, and effect on proliferation was assessed with and without anti-EGFR treatment. Expression of the candidate genes in patients' tumours treated with cetuximab was assessed by immunohistochemistry; survival analyses were performed comparing high vs low expression. RESULTS: Genes significantly upregulated in resistant cell lines were EGR1 (early growth response protein 1), HBEGF (heparin-binding epidermal growth factor-like growth factor), and AKT3 (AKT serine/threonine kinase 3). KD of each gene resulted in the respective cells being more sensitive to anti-EGFR treatment, suggesting that the resistant phenotype was reversed. In the pilot study of mCRC patients treated with cetuximab, both median PFS (1.38 months vs 6.79 months; HR 2.77 95% CI 1.2-19.4) and median OS (2.59 months vs 9.82 months; HR 3.0 95% CI 1.3-23.2) were significantly worse for those patients with high EGR1 expression. CONCLUSION: High EGR1 expression may be a candidate biomarker of resistance to anti-EGFR therapy.


Assuntos
Antineoplásicos/uso terapêutico , Cetuximab/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Proteína 1 de Resposta de Crescimento Precoce/biossíntese , Biomarcadores Tumorais/análise , Estudos de Coortes , Neoplasias Colorretais/mortalidade , Receptores ErbB/antagonistas & inibidores , Humanos , Estimativa de Kaplan-Meier , Projetos Piloto
8.
Br J Cancer ; 112(6): 963-70, 2015 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-25742472

RESUMO

BACKGROUND: Mutations affecting RAS genes are now established predictive markers of nonresponse to anti-EGFR antibodies in advanced CRC. This analysis assessed the prognostic and predictive impact of extended RAS and PIK3CA gene mutation status in patients receiving capecitabine plus or minus bevacizumab (±mitomycin C) in the randomised phase III MAX study. METHODS: DNA was extracted from archival macrodissected formalin-fixed paraffin-embedded tumour tissue. Mutation status was determined using pyrosequencing, confirmed with Sanger sequencing (for equivocal RAS) and correlated with efficacy outcomes. Predictive analyses were undertaken using a test for interaction involving both C vs CB+CBM. RESULTS: Of the available 280 of the 471 (59.4%) patients, mutations in KRAS exons 2, 3 and 4 and NRAS 2, 3 and 4 were as follows: 32%, 2.9%, 2.2%, 1.4%, 0.7% and 0% (total RAS MT 39%). The PIK3CA MT rate was 7.5% exon 9 and 3.6% exon 20. Extended RAS gene mutation status (WT vs MT) had no prognostic impact for PFS (HR 0.91 (0.71-1.17)) or OS (HR 0.95 (0.71-1.25)). The RAS gene mutation status was not predictive of the effectiveness of bevacizumab for PFS (HR 0.56 (0.37-0.85) for RAS MT and HR 0.69 (0.5-0.97) for RAS WT; P for interaction 0.50). The PIK3CA mutation was neither predictive for bevacizumab effect nor prognostic. CONCLUSION: Of KRAS exon 2 WT patients, 10% had additional RAS mutations. Neither all RAS gene mutation status nor PIK3CA mutation status was prognostic for PFS or OS, or predictive of bevacizumab outcome in patients with advanced CRC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Genes ras , Mutação , Fosfatidilinositol 3-Quinases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/administração & dosagem , Bevacizumab , Capecitabina , Classe I de Fosfatidilinositol 3-Quinases , Neoplasias Colorretais/patologia , DNA de Neoplasias/química , DNA de Neoplasias/genética , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/análogos & derivados , Humanos , Masculino , Mitomicina/administração & dosagem , Prognóstico
9.
Eur J Cancer ; 49(7): 1627-33, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23274198

RESUMO

BACKGROUND AND AIM: Significant tumour progression was observed during waiting time for treatment of head and neck cancer. To reduce waiting times, a Danish national policy of fast track accelerated clinical pathways was introduced in 2007. This study describes changes in waiting time and the potential influence of fast track by comparing waiting times in 2010 to 2002 and 1992. METHODS: Charts of all new patients diagnosed with squamous cell carcinoma of the oral cavity, pharynx and larynx at the five Danish head and neck oncology centres from January to April 2010 (n=253) were reviewed and compared to similar data from 2002 (n=211) and 1992 (n=168). RESULTS: The median time to diagnosis was 13 days (2010) versus 17 days (2002; p<0.001) and 20 days (1992; p<0.001). Median days from diagnosis to treatment start were 25 (2010) versus 47 (2002; p<0.001) and 31 (1992; p<0.001). Total pre-treatment time was median 41 days in 2010 versus 69 days (2002) (p<0.001) and 50 days (1992; p<0.001). Significantly more diagnostic imaging was done in 2010 compared to 2002 and 1992. When compared to current fast track standards the adherence to diagnosis improved slightly from 47% (1992) to 51% (2002) and 64% (2010); waiting time for radiotherapy was within standards for 7%, 1% and 22% of cases, respectively; waiting time for surgery was within standards for 17%, 22% and 48%, respectively. CONCLUSION: The study showed a significant reduction in delay of diagnosis and treatment of head and neck cancer in 2010, but still less than half of all patients start treatment within the current standards.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/terapia , Dinamarca , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde/normas , Programas Nacionais de Saúde/tendências , Assistência Individualizada de Saúde/normas , Assistência Individualizada de Saúde/tendências , Fatores de Tempo , Listas de Espera
10.
Avian Dis ; 55(1): 35-42, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21500633

RESUMO

We formulate a stochastic, spatial, discrete-time model of viral "Susceptible, Exposed, Infectious, Recovered" animal epidemics and apply it to an avian influenza epidemic in Pennsylvania in 1983-84. Using weekly data for the number of newly infectious cases collected during the epidemic, we find estimates for the latent period of the virus and the values of two parameters within the transmission kernel of the model. These data are then jackknifed on a progressive weekly basis to show how our estimates can be applied to an ongoing epidemic to generate continually improving values of certain epidemic parameters.


Assuntos
Galinhas , Influenza Aviária/epidemiologia , Modelos Biológicos , Animais , História do Século XX , Influenza Aviária/história , Pennsylvania/epidemiologia , Processos Estocásticos
11.
Neuroscience ; 150(1): 93-103, 2007 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-17996379

RESUMO

The present study aims at evaluating the significance of zinc ions on the development of brain damage in a model of traumatic brain injury (TBI). The zinc ion specific autometallographic technique, the ZnSe(AMG) method, using silver enhancement of in vivo-captured zinc ions bound in zinc-selenium nanocrystals was applied to follow changes in the vesicular zinc pattern. Balb/c mice, ZnT3 knockout (ZnT3-Ko) mice, a mouse genetically knocked out for the protein ZnT3 responsible for sequestering zinc into synaptic vesicles, and littermates from the genetically un-manipulated mother type mice, wild type (Wt), were used. The Wt and the Balb/c mice exhibited instantaneously a boost in the zinc staining adjacent to the lesion involving all six neocortical layers. Ultra-structural analyses revealed that the in vivo created ZnSe nanocrystals were still confined to the vesicles of the zinc-enriched (ZEN) neurons in the neuropil. No differences between the Balb/c and Wt mice were seen at any time points. In the ZnT3-Ko mice the ZEN terminals stayed void of AMG grains, but a number of neuronal somata around the lesion became loaded with ZnSe nanocrystals. These silver-enhanced ZnSe nanocrystals were confined to the cytoplasm of the somata and their proximal dendrites. No such soma staining was seen in the Wt or Balb/c mice. We speculate that vesicular zinc may not contribute to neuronal damage following TBI.


Assuntos
Lesões Encefálicas/metabolismo , Lesões Encefálicas/patologia , Vesículas Sinápticas/metabolismo , Zinco/metabolismo , Animais , Proteínas de Transporte , Proteínas de Transporte de Cátions , Modelos Animais de Doenças , Imuno-Histoquímica/métodos , Proteínas de Membrana/deficiência , Proteínas de Membrana Transportadoras , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Microscopia Imunoeletrônica/métodos , Neocórtex/patologia , Neurônios/metabolismo , Neurônios/ultraestrutura , Vesículas Sinápticas/ultraestrutura , Fatores de Tempo
12.
Histochem Cell Biol ; 123(6): 605-11, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15981003

RESUMO

An easy to perform autometallographic technique (AMG) for capturing zinc ions in Alzheimer plaques is presented. The possibility of visualizing loosely bound or free zinc ions in tissue by immersion autometallography (iZnS(AMG)) is a relatively recent development. The iZnS(AMG) staining is caused by zinc-sulphur nanocrystals created in 1-2 mm thick brain slices that are immersed in a 0.1% sodium sulphide, 3% glutaraldehyde phosphate buffered solution, the NeoTimm Solution (NTS), for 3 days. When the zinc-sulphur nanocrystals are subsequently silver-enhanced by autometallography, the plaques are readily identified as spheres of dark interlacing strands of different sizes, embedded in the pattern of zinc-enriched terminals. The zinc specificity of the iZnS(AMG) technique was tested by immersion of brain slides in the chelator DEDTC prior to the NTS immersion. The iZnS(AMG) detection of zinc ions is easily standardized and can be used in the quantification of plaques with stereological methods. This technique is the first to detect zinc in plaques in the cerebellum of transgenic PS1/APP mice and the first to detect zinc ions in plaques and dystrophic neurites at electron microscopical levels.


Assuntos
Doença de Alzheimer/metabolismo , Placa Amiloide/química , Zinco/análise , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Cristalografia/métodos , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica , Nanotecnologia/métodos , Placa Amiloide/patologia , Placa Amiloide/ultraestrutura , Presenilina-1
14.
J Clin Psychiatry ; 52(5): 234-8, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2033031

RESUMO

Of 317 consecutive cases seen in a dementia clinic, 19 (6%) had little or no objective evidence of cognitive impairment on clinical examination and extensive neuropsychological testing. Of the remaining 298 cases, 192 (64%) were diagnosed as probable or possible Alzheimer's disease (AD). Of the 19 nondemented cases, 8 (42%) were thought to have cognitive difficulty due to depression. In the AD group, only 4 cases (2%) were thought to be depressed and only 2 of the 4 met DSM-III-R criteria for major depression. There was no relationship between Hamilton Rating Scale for Depression scores and either cognitive or behavioral measurements of dementia severity, suggesting that the difference between the two groups was not due to underreporting by AD patients. The authors concluded that a tertiary care setting, depression is a common cause of cognitive complaints in persons without organic disease and a rare cause of excess morbidity in AD.


Assuntos
Demência/diagnóstico , Transtorno Depressivo/diagnóstico , Adulto , Idoso , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/epidemiologia , Assistência Ambulatorial , Comorbidade , Demência/complicações , Demência/epidemiologia , Transtorno Depressivo/complicações , Transtorno Depressivo/epidemiologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica
15.
Ugeskr Laeger ; 152(49): 3711-3, 1990 Dec 03.
Artigo em Dinamarquês | MEDLINE | ID: mdl-2264176

RESUMO

With the object of reducing the high of vacuum extraction in deliveries with lumbar epidural analgesia, we introduced "late pushing" in these deliveries in 1988. By this is understood that the parturient women is first encouraged to push when the orifice is completely dilated and the infant's head is visible at introitus. Before the "late pushing" was introduced, the frequency of vacuum extractions in deliveries with lumbar epidural analgesia was 44% of the vaginal deliveries. During the period of investigation, the frequency was 43%. Introduction of the "late pushing" thus did not result in any alteration (p greater than 0.4). Parturient women with lumbar epidural analgesia and slow progression of labour differed from the remainder of the parturient women with lumbar epidiral analgesia by significantly higher birth weights (4,000 g as compared with 3,400 g) and this may explain the increased frequency of vacuum extraction in this particular group of parturient women. The authors consider that lumbar epidural analgesia has the advantage that delivery is less painful for the mother without any simultaneous increased risk for the infant.


Assuntos
Analgesia Epidural , Analgesia Obstétrica , Vácuo-Extração/estatística & dados numéricos , Feminino , Humanos , Segunda Fase do Trabalho de Parto/fisiologia , Gravidez , Estudos Prospectivos
17.
Acta Pathol Microbiol Immunol Scand B ; 95(1): 79-81, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3565021

RESUMO

A case of cutaneous alternariosis is reported in the wife of a 73-year-old farmer. The diagnosis was verified culturally and histologically. The skin lesions were localized to legs, arms and face and were characterized by alternating spontaneous healing and formation of new lesions possibly due to autoinoculation from the lesions or re-exposure to the environment. The patient had a decreased resistance to infections owing to cancer - for which she had received X-ray treatment, chemotherapy and cortisone. This is the first reported Danish case.


Assuntos
Dermatomicoses , Idoso , Alternaria , Dinamarca , Feminino , Humanos , Tolerância Imunológica
18.
Women Health ; 5(3): 39-46, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7245784

RESUMO

This article discusses the history of Long Island's feminist health organization, The Women's Health Alliance of Long Island, Inc. This community-based women's group was formed in 1975 by a group of educators, practitioners, students, and intersted laywomen who were concerned about health care for women in New York City and Long Island. Today, services include a major Women and Health conference held each spring, a feminist health education center, several smaller presentations for specific groups, and related projects. Through our history, we have faced difficult decisions regarding our functions, goals, and structure. This article addresses the means we have used to mediate these decisions in order to continue our programs and to open our voluntary agency, Healthouse, which functions as a resource and educational center for women.


Assuntos
Educação em Saúde , Grupos de Autoajuda , Mulheres/educação , Feminino , Humanos , New York
19.
J Med Chem ; 20(9): 1152-9, 1977 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-926115

RESUMO

The preparation and gastric antisecretory activity of a series of 15-deoxy-16-hydroxyprostaglandin analogues are described. The compounds were tested intravenously in histamine-stimulated Heidenhain pouch dogs in relation to the reference standards PGE1 and PGE1 methyl ester (PGE1ME). The parent compound of this seris, (+/-)-15-deoxy-16alpha,beta-hydroxyprostaglandin E1 methyl ester (3), was found to be equipotent to the reference standard PGE1ME. Methylation at C-16 of 3 produced 8 which was found to be some 40 times more potent than PGE1. In sharp contrast, addition of two methyl groups to 3 at C15 or C17 markedly reduced the antisecretory action. The 16-ethyl analogue of 3 also showed reduced potency. Removal or epimerization of the C-11 hydroxy group of 8 reduced the activity. Likewise, hydrogenation or changing the stereochemistry of the 13,14 double bond from trans to cis decreased the activity. On the other hand, omega-homologation of 8 or the introduction of a cis-5,6 double bond did not affect the potency. From these studies, it appears that 8, 16, and 17 possess optimum gastric antisecretory effects in this series.


Assuntos
Prostaglandinas E Sintéticas/síntese química , Animais , Cães , Feminino , Suco Gástrico/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Prostaglandinas E Sintéticas/farmacologia , Relação Estrutura-Atividade
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