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1.
Nat Mater ; 22(4): 459-465, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36658327

RESUMO

Spin-valley locking is ubiquitous among transition metal dichalcogenides with local or global inversion asymmetry, in turn stabilizing properties such as Ising superconductivity, and opening routes towards 'valleytronics'. The underlying valley-spin splitting is set by spin-orbit coupling but can be tuned via the application of external magnetic fields or through proximity coupling. However, only modest changes have been realized to date. Here, we investigate the electronic structure of the V-intercalated transition metal dichalcogenide V1/3NbS2 using microscopic-area spatially resolved and angle-resolved photoemission spectroscopy. Our measurements and corresponding density functional theory calculations reveal that the bulk magnetic order induces a giant valley-selective Ising coupling exceeding 50 meV in the surface NbS2 layer, equivalent to application of a ~250 T magnetic field. This energy scale is of comparable magnitude to the intrinsic spin-orbit splittings, and indicates how coupling of local magnetic moments to itinerant states of a transition metal dichalcogenide monolayer provides a powerful route to controlling their valley-spin splittings.

2.
Am J Physiol Heart Circ Physiol ; 322(4): H597-H606, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35179975

RESUMO

In utero exposure to glucocorticoids in late gestation programs changes in cardiovascular function. The objective of this study was to determine the degree to which angiotensin II mediates sex-biased changes in autonomic function as well as basal and stress-responsive cardiovascular function following in utero glucocorticoid exposure. Pregnant rats were administered the synthetic glucocorticoid dexamethasone (Dex; 0.4 mg/kg/day sc) or vehicle on gestation days 18-21. Mean arterial pressure, heart rate, and heart rate variability (HRV) were measured via radiotelemetry in freely moving, conscious adult rats. To evaluate the impact of stress, rats were placed in a restraint tube for 20 min. In a separate cohort of rats, restraint stress was performed before and after chronic treatment with the angiotensin type 1 receptor antagonist, losartan (30 mg/kg/day ip). Frequency domain analysis of HRV was evaluated, and data were integrated into low-frequency (LF, 0.20-0.75 Hz) and high-frequency (HF, 0.75-2.00 Hz) bands. Prenatal Dex resulted in an exaggerated pressor and heart rate response to restraint in female offspring that was attenuated by prior losartan treatment. HF power was higher in vehicle-exposed female rats compared with Dex females. Following losartan, HF power was equivalent between female vehicle and Dex-exposed rats. In utero exposure to Dex produced female-biased alterations in stress-responsive cardiovascular function, which may be indicative of a reduction in parasympathetic activity. Moreover, these findings suggest this autonomic dysregulation may be mediated, in part, by long-term changes in renin-angiotensin signaling.NEW & NOTEWORTHY Our findings reveal the involvement of angiotensin II on sex-selective cardiovascular function and autonomic changes in adult offspring exposed to dexamethasone during the last 4 days of gestation. We show that angiotensin II receptor blockade reverses the exaggerated pressor and heart rate response to acute restraint stress and the autonomic dysregulation observed in female, but not male, offspring exposed to dexamethasone in utero.


Assuntos
Bloqueadores do Receptor Tipo 2 de Angiotensina II , Efeitos Tardios da Exposição Pré-Natal , Angiotensina II/farmacologia , Bloqueadores do Receptor Tipo 2 de Angiotensina II/farmacologia , Animais , Pressão Sanguínea/fisiologia , Dexametasona/toxicidade , Feminino , Masculino , Gravidez , Ratos , Receptor Tipo 1 de Angiotensina
3.
Nature ; 531(7592): 70-3, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26935696

RESUMO

Cosmic rays are the highest-energy particles found in nature. Measurements of the mass composition of cosmic rays with energies of 10(17)-10(18) electronvolts are essential to understanding whether they have galactic or extragalactic sources. It has also been proposed that the astrophysical neutrino signal comes from accelerators capable of producing cosmic rays of these energies. Cosmic rays initiate air showers--cascades of secondary particles in the atmosphere-and their masses can be inferred from measurements of the atmospheric depth of the shower maximum (Xmax; the depth of the air shower when it contains the most particles) or of the composition of shower particles reaching the ground. Current measurements have either high uncertainty, or a low duty cycle and a high energy threshold. Radio detection of cosmic rays is a rapidly developing technique for determining Xmax (refs 10, 11) with a duty cycle of, in principle, nearly 100 per cent. The radiation is generated by the separation of relativistic electrons and positrons in the geomagnetic field and a negative charge excess in the shower front. Here we report radio measurements of Xmax with a mean uncertainty of 16 grams per square centimetre for air showers initiated by cosmic rays with energies of 10(17)-10(17.5) electronvolts. This high resolution in Xmax enables us to determine the mass spectrum of the cosmic rays: we find a mixed composition, with a light-mass fraction (protons and helium nuclei) of about 80 per cent. Unless, contrary to current expectations, the extragalactic component of cosmic rays contributes substantially to the total flux below 10(17.5) electronvolts, our measurements indicate the existence of an additional galactic component, to account for the light composition that we measured in the 10(17)-10(17.5) electronvolt range.

4.
Ann Oncol ; 32(9): 1101-1110, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34089836

RESUMO

Rat sarcoma (RAS) is the most frequently mutated oncogene in human cancer, with Kirsten rat sarcoma (KRAS) being the most commonly mutated RAS isoform. Overall, KRAS accounts for 85% of RAS mutations observed in human cancers and is present in 35% of lung adenocarcinomas (LUADs). While the use of targeted therapies and immune checkpoint inhibitors (CPIs) has drastically changed the treatment landscape of advanced non-small-cell lung cancer (NSCLC) in recent years, historic attempts to target KRAS (both direct and indirect approaches) have had little success, and no KRAS-specific targeted therapies have been approved to date for patients in this molecular subset of NSCLC. With the discovery by Ostrem, Shokat, and colleagues of the switch II pocket on the surface of the active and inactive forms of KRAS, we now have an improved understanding of the complex interactions involved in the RAS family of signaling proteins which has led to the development of a number of promising direct KRASG12C inhibitors, such as sotorasib and adagrasib. In previously treated patients with KRASG12C-mutant NSCLC, clinical activity has been shown for both sotorasib and adagrasib monotherapy; these data suggest promising new treatment options are on the horizon. With the stage now set for a new era in the treatment of KRASG12C-mutated NSCLC, many questions remain to be answered in order to further elucidate the mechanisms of resistance, how best to use combination strategies, and if KRASG12C inhibitors will have suitable activity in earlier lines of therapy for patients with advanced/metastatic NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , Piperazinas , Proteínas Proto-Oncogênicas p21(ras)/genética , Piridinas , Pirimidinas
5.
J Biol Regul Homeost Agents ; 32(2 Suppl. 1): 179-183, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29460538

RESUMO

Endocarditis is a cardiovascular disease caused by the inflammation of the inner tissues of the heart, the endocardium, usually of the valves. Bacteraemia is essential in the development of endocarditis, and there are some findings that the main pathogens of endocarditis are viridans group streptococci: Streptococcus oralis, Streptococcus sanguinis, and Enterococcus faecalis. There is strong evidence that endocarditis bacteria are present in the tonsillar microbiota, so that tonsillar infection is associated with an increased risk of endocarditis. The aim of this manuscript is to investigate the presence of the main pathogens of endocarditis in tonsillar microbiota of an Afghan population group. A sample of 80 tonsil swabs were analyzed by quantitative real time PCR to detect endocarditis pathogens and an estimation of the total bacterial load. The median bacterial load in PCR reaction was 1.4x106 (interquartile range 4,7x105 - 2,9x106). Three species, S. Oralis, S. Sanguinis, and E. Faecalis were found in large amounts in all specimens. On the other hand, S. Mitis was never detected. The S. Aureus was found in 3 samples with a prevalence of 0.04 (C.I. 0.01-0.10). The S. Mutans was found in 33 samples with a prevalence of 0.41 (C.I. 0.31-0.52). Endocarditis bacteria has been found into the tonsillar microbiota, so there is sufficient evidence to justify that the oral cavity is a reservoir of endocarditis bacteria that can have a significant impact on the cardiovascular function.


Assuntos
Bactérias/isolamento & purificação , Endocardite/microbiologia , Mucosa/microbiologia , Tonsila Palatina/microbiologia , Afeganistão/epidemiologia , Humanos , Staphylococcus aureus/isolamento & purificação
6.
J Biol Regul Homeost Agents ; 32(2 Suppl. 1): 185-190, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29460539

RESUMO

Some studies have evidenced the role of human polyomaviruses in head and neck squamous cell carcinoma. BK, JC and SV40 human polyoma viruses are widely recognized as etiological agents associated with malignancies. The aim of this study was to analyse the prevalence of BK, IC and SV40 in tonsillar microbiota in a group of Afghan volunteers. A sample of the tonsillar microbiota was taken from a single site using a sterile oral swab paper stick. A fixed volume of purified DNA from each sample was tested by quantitative real-time polymerase chain reactions to evaluate the number of human cells and the number of viral genomes in each sample. The cell number was evaluated via the quantification of a single copy genomic sequence, which is located in the HMBS locus. The median analyzed cell number in each reaction was 4343 (interquartile range 2074-8470). SV40 was never detected, while prevalence rate was 0.11 (C.I. 0.06-0.20) for BK and 0.10 (C.I. 0.05-0.19) for JC. Further studies are necessary to clarify whether polyomaviruses can be considered a risk factor of oral, oropharyngeal and laryngeal malignancies.


Assuntos
Tonsila Palatina/microbiologia , Polyomavirus/isolamento & purificação , Afeganistão/epidemiologia , Humanos , Infecções por Polyomavirus/epidemiologia , Infecções por Polyomavirus/microbiologia , Prevalência , Vírus 40 dos Símios/isolamento & purificação
7.
J Biol Regul Homeost Agents ; 32(2 Suppl. 1): 191-196, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29460540

RESUMO

Cancer of the oral cavity is known to have a diverse aetiology that includes infectious agents. Human papilloma virus has been found to be associated with several types of human cancer, inclusive of cervical, vulvar, vaginal, penile, anal, and cancer of tonsil. The aim of this manuscript is to investigate the presence of human papilloma virus in tonsillar microbiota of an Afghan population group. A sample of the tonsillar microbiota was collected by oral swab paper stick from 80 healthy donors. The sample was investigated for the presence of high-risk human papillomavirus types 16, 18, 31 and 45 by real time PCR. Eight samples produced some positive endpoint signals for human papillomaviruses. The human papillomavirus 31 was the unique papillomavirus detected; its calculated prevalence rate was 0.10 (C.I. 0.05-0.19). However, the viral load was always very low, in the order of 10-3 viral genomes per cell. The high prevalence of high-risk human papillomavirus in healthy population suggest a need for further investigation on virus spreading and supports the development of vaccination strategies.


Assuntos
Microbiota , Tonsila Palatina/microbiologia , Polyomavirus/isolamento & purificação , Afeganistão/epidemiologia , Feminino , Humanos , Masculino , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/microbiologia , Polyomavirus/classificação , Polyomavirus/genética , Infecções por Polyomavirus/epidemiologia , Infecções por Polyomavirus/microbiologia , Prevalência
8.
Phys Rev Lett ; 118(1): 012701, 2017 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-28106447

RESUMO

This Letter reports a study of the highly debated ^{10}Li structure through the d(^{9}Li,p)^{10}Li one-neutron transfer reaction at 100 MeV. The ^{10}Li energy spectrum is measured up to 4.6 MeV and angular distributions corresponding to different excitation energy regions are reported for the first time. The comparison between data and theoretical predictions, including pairing correlation effects, shows the existence of a p_{1/2} resonance at 0.45±0.03 MeV excitation energy, while no evidence for a significant s-wave contribution close to the threshold energy is observed. Moreover, two high-lying structures are populated at 1.5 and 2.9 MeV. The corresponding angular distributions suggest a significant s_{1/2} partial-wave contribution for the 1.5 MeV structure and a mixing of configurations at higher energy, with the d_{5/2} partial-wave contributing the most to the cross section.

9.
Phys Rev Lett ; 119(13): 132501, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-29341708

RESUMO

The decay path of the Hoyle state in ^{12}C (E_{x}=7.654 MeV) has been studied with the ^{14}N(d,α_{2})^{12}C(7.654) reaction induced at 10.5 MeV. High resolution invariant mass spectroscopy techniques have allowed us to unambiguously disentangle direct and sequential decays of the state passing through the ground state of ^{8}Be. Thanks to the almost total absence of background and the attained resolution, a fully sequential decay contribution to the width of the state has been observed. The direct decay width is negligible, with an upper limit of 0.043% (95% C.L.). The precision of this result is about a factor 5 higher than previous studies. This has significant implications on nuclear structure, as it provides constraints to 3α cluster model calculations, where higher precision limits are needed.

12.
J Oncol Res Ther ; 9(3)2024.
Artigo em Inglês | MEDLINE | ID: mdl-39210964

RESUMO

Nicotine exposure through the use of electronic delivery systems (vaping) has been found to elevate the risk of certain conditions of the lungs, e.g., vaping associated lung injury, EVALI). However, the potential impact of vaping on lung cancer risk remains unexplored. We, therefore, examined the association of vaping and cigarette smoking with lung cancer risk in a case control study conducted in central Ohio. The study design compared 4,975 individuals with recently diagnosed pathologically confirmed carcinoma of the lung to 27,294 controls without cancer that were group matched at a 5:1 ratio to the cases by age, gender, race and location of residence. Odds ratios (OR) adjusted for gender, age and race revealed a fourfold higher risk of lung cancer among individuals who vaped in combination with chronic smoking (OR=58.9, 95% CI=47.3-70.5) versus individuals who only smoked cigarettes (OR=13.9, 95% CI=12.7-15.3, P<0.001). Further adjustment for prevalent comorbidities, chronic obstructive pulmonary disease and coronary artery disease, reduced the magnitude of the OR, but the risk for vaping and smoking (OR=38.7, 95% CI =31.5-47.6) remained fourfold higher than for smoking alone (OR=9.6, 95% CI=8.7-10.6, P<0.001). This finding was consistent for men and women, with adjustment for pack-years of smoking, and for the main histological cell types of lung cancer. Our results suggest that the addition of vaping to smoking accelerates the risk of developing lung cancer.

13.
Phys Rev Lett ; 111(6): 065503, 2013 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-23971584

RESUMO

We present here an unprecedented way of quantifying the number of dislocations in microcrystals. This method relies on a combination of several state-of-the-art techniques: coherent x-ray diffraction used as a local probe, together with the controlled compression of micro-objects. We demonstrate that by using this method, dislocations in the microcrystal can be detected and their number precisely quantified. This cannot be done with other techniques in a nondestructive way. Our method opens a route for the study of many small-scale systems with defect-dependent physical properties and it could become a critical tool for addressing future challenges in nanotechnology.

14.
Nat Genet ; 13(2): 210-3, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8640228

RESUMO

Tumours express a variety of novel epitopes which represent potential immune targets, and thus clinically evident tumours are thought to have effectively avoided immune recognition and elimination. Transporters associated with antigen presentation (TAP) are thought to be responsible for conveying intracellular peptides into the endoplasmic reticulum for complex formation with class I MHC and subsequent recognition by cytotoxic T lymphocytes. In this study, we evaluated 79 human solid tumours and cell lines for genetic abnormalities in TAP1 that might have led to an acquired loss of antigen presenting ability. A novel sequence (R659Q) was discovered near the ATP binding site in a human small cell lung cancer (SCLC) cell line, H1436. This cell line is heterozygous for this allele, but only the R659Q allele is transcribed into RNA. Even though the R659Q protein is expressed, these cells act as if they were TAP deficient by peptide binding and antigen presentation studies, which are restored after transfection of a functional TAP1 allele. This is the first evidence for a naturally occuring protein structural defect resulting in defective peptide transport in a human solid tumour.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Antígenos de Histocompatibilidade Classe I/genética , Neoplasias Pulmonares/genética , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Alelos , Sequência de Bases , Sítios de Ligação , Carcinoma de Células Pequenas/genética , Carcinoma de Células Pequenas/patologia , Carcinoma de Células Pequenas/virologia , Códon , Heterozigoto , Antígenos de Histocompatibilidade Classe I/biossíntese , Antígenos de Histocompatibilidade Classe I/efeitos dos fármacos , Humanos , Interferon gama/farmacologia , Neoplasias Pulmonares/patologia , Dados de Sequência Molecular , Orthomyxoviridae , Polimorfismo Conformacional de Fita Simples , Linfócitos T Citotóxicos/imunologia , Células Tumorais Cultivadas
15.
ESMO Open ; 8(5): 101627, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37703595

RESUMO

BACKGROUND: Thymic epithelial tumors (TETs) are rare neoplasms arising in the mediastinum, including thymic carcinomas and thymomas. Due to their rarity, little is known about the genomic profiles of TETs. Herein, we investigated the genomic characteristics of TETs evaluated in a large comprehensive genomic profiling database in a real-world setting. METHODS: We included data from two different cohorts: Foundation Medicine Inc. (FMI) in the United States and the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) in Japan. Samples profiled were examined for all classes of alterations in 253 genes targeted across all assays. Tumor mutational burden (TMB) and microsatellite instability (MSI) were also evaluated. RESULTS: A total of 794 patients were collected in our study, including 722 cases from FMI and 72 cases from C-CAT. In the FMI data, CDKN2A (39.9%), TP53 (30.2%) and CDKN2B (24.6%) were frequently altered in thymic carcinoma, versus TP53 (7.8%), DNMT3A (6.8%), and CDKN2A (5.8%) in thymoma. TMB-high (≥10 mutations/Mb) and MSI were present in 7.0% and 2.3% of thymic carcinomas, and 1.6% and 0.3% of thymomas, respectively. Within C-CAT data, CDKN2A (38.5%), TP53 (36.5%) and CDKN2B (30.8%) were also frequently altered in thymic carcinoma, while alterations of TSC1, SETD2 and LTK (20.0% each) were found in thymoma. CONCLUSIONS: To the best of our knowledge, this is the largest cohort in which genomic alterations, TMB and MSI status of TETs were investigated. Potential targets for treatment previously unbeknownst in TETs are identified in this study, entailing newfound opportunities to advance therapeutic development.


Assuntos
Neoplasias Epiteliais e Glandulares , Timoma , Neoplasias do Timo , Humanos , Timoma/genética , Timoma/patologia , Neoplasias do Timo/genética , Neoplasias do Timo/patologia , Neoplasias Epiteliais e Glandulares/genética , Genômica
16.
Horm Metab Res ; 44(8): 598-606, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22549397

RESUMO

A variety of models have been developed to better understand the mechanisms underlying individual variation in susceptibility to obesity. This review discusses several of these models and explores their role in understanding individual vulnerability to metabolic disease and the environmental factors around which metabolic perturbations occur. Recently, the focus of models has shifted towards heterogeneous populations, in which individuals characterized by a high vulnerability and individuals that are seemingly resistant can be identified. The use of these heterogeneous studies has lead to the identification of several novel biomarkers predicting obesity. This review therefore focuses on nontraditional factors, which are not directly implicated in metabolic regulation. First, the evidence from rodent knockout models for genetic factors involved in obesity is discussed. Second, the role of a stressful environment, particularly the early life environment is investigated along with a discussion of circadian disruption and metabolic disorders. Finally, the impact of sex-steroids, as exemplified by polycystic ovarian syndrome, is discussed. Overall, the data presented in our review demonstrate that in most cases interplay between genetic and environmental factors best predicts disease development. Our review shows that susceptibility to obesity may be explained by complex interactions between traditional homeostatic mechanisms, such as the hypothalamic peptide, and less studied mechanisms, like steroids and neurotrophic factors.


Assuntos
Gônadas/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Metabolismo/genética , Modelos Biológicos , Sistema Hipófise-Suprarrenal/metabolismo , Estresse Fisiológico/genética , Animais , Humanos
17.
AJNR Am J Neuroradiol ; 43(1): 24-32, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34857514

RESUMO

BACKGROUND AND PURPOSE: Quantitative volumetric segmentation of gliomas has important implications for diagnosis, treatment, and prognosis. We present a deep-learning model that accommodates automated preoperative and postoperative glioma segmentation with a pipeline for clinical implementation. Developed and engineered in concert, the work seeks to accelerate clinical realization of such tools. MATERIALS AND METHODS: A deep learning model, autoencoder regularization-cascaded anisotropic, was developed, trained, and tested fusing key elements of autoencoder regularization with a cascaded anisotropic convolutional neural network. We constructed a dataset consisting of 437 cases with 40 cases reserved as a held-out test and the remainder split 80:20 for training and validation. We performed data augmentation and hyperparameter optimization and used a mean Dice score to evaluate against baseline models. To facilitate clinical adoption, we developed the model with an end-to-end pipeline including routing, preprocessing, and end-user interaction. RESULTS: The autoencoder regularization-cascaded anisotropic model achieved median and mean Dice scores of 0.88/0.83 (SD, 0.09), 0.89/0.84 (SD, 0.08), and 0.81/0.72 (SD, 0.1) for whole-tumor, tumor core/resection cavity, and enhancing tumor subregions, respectively, including both preoperative and postoperative follow-up cases. The overall total processing time per case was ∼10 minutes, including data routing (∼1 minute), preprocessing (∼6 minute), segmentation (∼1-2 minute), and postprocessing (∼1 minute). Implementation challenges were discussed. CONCLUSIONS: We show the feasibility and advantages of building a coordinated model with a clinical pipeline for the rapid and accurate deep learning segmentation of both preoperative and postoperative gliomas. The ability of the model to accommodate cases of postoperative glioma is clinically important for follow-up. An end-to-end approach, such as used here, may lead us toward successful clinical translation of tools for quantitative volume measures for glioma.


Assuntos
Aprendizado Profundo , Glioma , Glioma/diagnóstico por imagem , Glioma/cirurgia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Redes Neurais de Computação , Período Pós-Operatório
18.
J Synchrotron Radiat ; 18(Pt 3): 413-7, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21525649

RESUMO

Three-dimensional reciprocal-space maps of a single SiGe island around the Si(004) Bragg peak are recorded using an energy-tuning technique with a microfocused X-ray beam with compound refractive lenses as focusing optics. The map is in agreement with simulated data as well as with a map recorded by an ordinary rocking-curve scan. The energy-tuning approach circumvents both the comparatively large sphere of confusion of diffractometers compared with nanostructures and vibrations induced by motors. Thus, this method offers new possibilities for novel combinations of three-dimensional micro- and nano-focused X-ray diffraction with complex in situ sample environments such as scanning probe microscopes.

19.
Opt Express ; 19(20): 19223-32, 2011 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-21996864

RESUMO

A detailed characterization of the coherent x-ray wavefront produced by a partially illuminated Fresnel zone plate is presented. We show, by numerical and experimental approaches, how the beam size and the focal depth are strongly influenced by the illumination conditions, while the phase of the focal spot remains constant. These results confirm that the partial illumination can be used for coherent diffraction experiments. Finally, we demonstrate the possibility of reconstructing the complex-valued illumination function by simple measurement of the far field intensity in the specific case of partial illumination.


Assuntos
Algoritmos , Simulação por Computador , Processamento de Imagem Assistida por Computador , Difração de Raios X/instrumentação , Desenho de Equipamento , Análise de Fourier , Raios X
20.
Nat Med ; 2(10): 1096-103, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8837607

RESUMO

Inadequate presentation of tumor antigens by host professional antigen-presenting cells (APCs), including dendritic cells (DCs), is one potential mechanism for the escape of tumors from the host immune system. Here, we show that human cancer cell lines release a soluble factor or factors that dramatically affect DC maturation from precursors without affecting the function of relatively mature DCs. One factor responsible for these effects was identified as vascular endothelial growth factor (VEGF). Thus, VEGF may play a broader role in the pathogenesis of cancer than was previously thought, and therapeutic blockade of VEGF action may improve prospects for immunotherapy as well as inhibit tumor neovasculature.


Assuntos
Células Dendríticas/efeitos dos fármacos , Fatores de Crescimento Endotelial/fisiologia , Linfocinas/fisiologia , Proteínas de Neoplasias/fisiologia , Neoplasias/metabolismo , Apresentação de Antígeno/efeitos dos fármacos , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Células Dendríticas/imunologia , Fatores de Crescimento Endotelial/farmacologia , Endotélio Vascular/metabolismo , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Tolerância Imunológica/efeitos dos fármacos , Linfocinas/farmacologia , Dados de Sequência Molecular , Proteínas de Neoplasias/farmacologia , Receptores Proteína Tirosina Quinases/análise , Receptores de Fatores de Crescimento/análise , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes/farmacologia , Subpopulações de Linfócitos T/imunologia , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
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