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1.
Heliyon ; 10(8): e29496, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38681590

RESUMEN

The woodworking applications are a fast-growing field that aims to create advanced coatings with superior wear resistance, reduced friction, and robust corrosion protection. Chromium silicon carbonitride (CrSiCN) coatings have emerged as a promising solution that offers a unique combination of properties ideal for various industrial applications. The C/N ratio significantly influences the coatings' mechanical and tribological properties. By optimizing the C/N ratio, this research aims to reveal new insights for CrSiCN coatings, enhancing their application in environments that require durability, efficiency, and longevity. In this paper, the effect of the C/N ratio on the structural, mechanical, and corrosion resistance of CrSiCN coatings deposited by cathodic arc evaporation on different steel substrates was studied. The main purpose was to enhance the mechanical and anticorrosion properties of the CrSiCN coatings and to select the optimum parameters for the deposition of layers with superior properties. The results showed that the final properties can be tailored by choosing specific deposition conditions. In this case, the C/N ratio proved to be critical since coatings with higher carbon content presented enhanced corrosion resistance, being able to withstand operating conditions similar to real-life.

2.
NMR Biomed ; 37(6): e5124, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38403798

RESUMEN

Advanced intraoperative MR images (ioMRI) acquired during the resection of pediatric brain tumors could offer additional physiological information to preserve healthy tissue. With this work, we aimed to develop a protocol for ioMRI with increased sensitivity for arterial spin labeling (ASL) and diffusion MRI (dMRI), optimized for patient positioning regularly used in the pediatric neurosurgery setting. For ethical reasons, ASL images were acquired in healthy adult subjects that were imaged in the prone and supine position. After this, the ASL cerebral blood flow (CBF) was quantified and compared between both positions. To evaluate the impact of the RF coils setups on image quality, we compared different setups (two vs. four RF coils) by looking at T1-weighted (T1w) signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), as well as undertaking a qualitative evaluation of T1w, T2w, ASL, and dMR images. Mean ASL CBF did not differ between the surgical prone and supine positions in any of the investigated regions of interest or the whole brain. T1w SNR (gray matter: p = 0.016, 34% increase; white matter: p = 0.016, 32% increase) and CNR were higher (p = 0.016) in the four versus two RF coils setups (18.0 ± 1.8 vs. 13.9 ± 1.8). Qualitative evaluation of T1w, T2w, ASL, and dMR images resulted in acceptable to good image quality and did not differ statistically significantly between setups. Only the nonweighted diffusion image maps and corticospinal tract reconstructions yielded higher image quality and reduced susceptibility artifacts with four RF coils. Advanced ioMRI metrics were more precise with four RF coils as the standard deviation decreased. Taken together, we have investigated the practical use of advanced ioMRI during pediatric neurosurgery. We conclude that ASL CBF quantification in the surgical prone position is valid and that ASL and dMRI acquisition with two RF coils can be performed adequately for clinical use. With four versus two RF coils, the SNR of the images increases, and the sensitivity to artifacts reduces.


Asunto(s)
Imagen por Resonancia Magnética , Procedimientos Neuroquirúrgicos , Relación Señal-Ruido , Humanos , Masculino , Femenino , Imagen por Resonancia Magnética/métodos , Niño , Adulto , Circulación Cerebrovascular/fisiología , Marcadores de Spin , Imagen de Difusión por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Encéfalo/cirugía
3.
Magn Reson Imaging ; 108: 22-28, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38309377

RESUMEN

The integrity of vessel walls and changes in blood flow are involved in many diseases, and information about these anatomical and physiological conditions is important for a diagnosis. There are several different angiography methods that can be used to generate images for diagnostic purposes, but often using different imaging techniques and MR sequences. The purpose of this study was to develop a method that allows time-resolved, vessel-selective simultaneous bright and black blood imaging by vesselselective blood saturation. Measurements in six volunteers were performed to evaluate the time-resolved bright blood angiography and the significance of the generated black blood contrast. It was shown that this method can be used to generate a black blood contrast with a sufficient signal difference to the surrounding gray matter in addition to the time-resolved and vessel-selective bright blood contrast. Using post-processing methods, whole brain angiograms can be calculated from the acquired data.


Asunto(s)
Angiografía , Angiografía por Resonancia Magnética , Humanos , Radiografía , Angiografía por Resonancia Magnética/métodos , Imagenología Tridimensional/métodos
4.
Magn Reson Med ; 91(5): 1787-1802, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37811778

RESUMEN

PURPOSE: To create an inventory of image processing pipelines of arterial spin labeling (ASL) and list their main features, and to evaluate the capability, flexibility, and ease of use of publicly available pipelines to guide novice ASL users in selecting their optimal pipeline. METHODS: Developers self-assessed their pipelines using a questionnaire developed by the Task Force 1.1 of the ISMRM Open Science Initiative for Perfusion Imaging. Additionally, each publicly available pipeline was evaluated by two independent testers with basic ASL experience using a scoring system created for this purpose. RESULTS: The developers of 21 pipelines filled the questionnaire. Most pipelines are free for noncommercial use (n = 18) and work with the standard NIfTI (Neuroimaging Informatics Technology Initiative) data format (n = 15). All pipelines can process standard 3D single postlabeling delay pseudo-continuous ASL images and primarily differ in their support of advanced sequences and features. The publicly available pipelines (n = 9) were included in the independent testing, all of them being free for noncommercial use. The pipelines, in general, provided a trade-off between ease of use and flexibility for configuring advanced processing options. CONCLUSION: Although most ASL pipelines can process the common ASL data types, only some (namely, ASLPrep, ASLtbx, BASIL/Quantiphyse, ExploreASL, and MRICloud) are well-documented, publicly available, support multiple ASL types, have a user-friendly interface, and can provide a useful starting point for ASL processing. The choice of an optimal pipeline should be driven by specific data to be processed and user experience, and can be guided by the information provided in this ASL inventory.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Marcadores de Spin , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Arterias , Imagen de Perfusión , Circulación Cerebrovascular , Imagen por Resonancia Magnética/métodos , Perfusión
5.
Magn Reson Med ; 91(5): 1743-1760, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37876299

RESUMEN

The 2015 consensus statement published by the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group and the European Cooperation in Science and Technology ( COST) Action ASL in Dementia aimed to encourage the implementation of robust arterial spin labeling (ASL) perfusion MRI for clinical applications and promote consistency across scanner types, sites, and studies. Subsequently, the recommended 3D pseudo-continuous ASL sequence has been implemented by most major MRI manufacturers. However, ASL remains a rapidly and widely developing field, leading inevitably to further divergence of the technique and its associated terminology, which could cause confusion and hamper research reproducibility. On behalf of the ISMRM Perfusion Study Group, and as part of the ISMRM Open Science Initiative for Perfusion Imaging (OSIPI), the ASL Lexicon Task Force has been working on the development of an ASL Lexicon and Reporting Recommendations for perfusion imaging and analysis, aiming to (1) develop standardized, consensus nomenclature and terminology for the broad range of ASL imaging techniques and parameters, as well as for the physiological constants required for quantitative analysis; and (2) provide a community-endorsed recommendation of the imaging parameters that we encourage authors to include when describing ASL methods in scientific reports/papers. In this paper, the sequences and parameters in (pseudo-)continuous ASL, pulsed ASL, velocity-selective ASL, and multi-timepoint ASL for brain perfusion imaging are included. However, the content of the lexicon is not intended to be limited to these techniques, and this paper provides the foundation for a growing online inventory that will be extended by the community as further methods and improvements are developed and established.


Asunto(s)
Encéfalo , Imagen por Resonancia Magnética , Reproducibilidad de los Resultados , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Imagen de Perfusión/métodos , Marcadores de Spin , Circulación Cerebrovascular/fisiología , Angiografía por Resonancia Magnética/métodos , Perfusión
6.
Emerg Med J ; 41(4): 249-254, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-37968092

RESUMEN

BACKGROUND: In 2019, the emergency medical services (EMS) covering the western Norway Regional Health Authority area implemented its version of the prehospital clinical criteria G-FAST (Gaze deviation, Facial palsy, Arm weakness, Visual loss, Speech disturbance) to detect acute ischaemic stroke (AIS) with large vessel occlusion (LVO). For patients with gaze deviation and at least one other G-FAST symptom, a primary stroke centre (PSC) may be bypassed and the patient taken directly to a comprehensive stroke centre (CSC) for rapid endovascular treatment (EVT) evaluation. The study aim was to investigate the efficacy of the G-FAST criteria for LVO patient selection and direct transfer to a CSC. METHODS: This retrospective study included patients with code-red emergency medical communication centre (EMCC) stroke suspicion ambulance dispatch between August to December 2020. Stroke suspicion was defined as having at least one G-FAST symptom at EMS arrival. We obtained patient data from dispatches from EMCCs, EMS records and local EVT registries. Clinical features, CT images, and reperfusion treatment were recorded. The test characteristics for gaze deviation plus one other G-FAST symptom in detecting LVO were determined. RESULTS: Among 643 patients, 59 were diagnosed with LVO at hospital arrival. In this group, seven fulfilled the G-FAST criteria for direct transport to a CSC at EMS arrival on scene, resulting in a sensitivity of 12% (95% CI 5% to 23%). The specificity was 99.66% (95% CI 98.77% to 99.96%), the positive predictive value 78%, and the negative predictive value 92%. EVT was performed in 64% (38/59) of LVO cases. Median time from PSC arrival to start of EVT at a CSC was 163 min. CONCLUSION: The use of local G-FAST prehospital criteria by EMS personnel to identify patients with AIS with LVO is not suitable for selection of patients with LVO for direct transfer to a CSC.


Asunto(s)
Isquemia Encefálica , Servicios Médicos de Urgencia , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Isquemia Encefálica/complicaciones , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/terapia , Estudios Retrospectivos , Servicios Médicos de Urgencia/métodos
8.
Eur J Nucl Med Mol Imaging ; 50(10): 3011-3021, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37147478

RESUMEN

PURPOSE: We aimed to assess prevalence, distribution, and intensity of in-vivo arterial wall fibroblast activation protein (FAP) uptake, and its association with calcified plaque burden, cardiovascular risk factors (CVRFs), and FAP-avid tumor burden. METHODS: We analyzed 69 oncologic patients who underwent [68 Ga]Ga-FAPI-04 PET/CT. Arterial wall FAP inhibitor (FAPI) uptake in major vessel segments was evaluated. We then investigated the associations of arterial wall uptake with calcified plaque burden (including number of plaques, plaque thickness, and calcification circumference), CVRFs, FAP-positive total tumor burden, and image noise (coefficient of variation, from normal liver parenchyma). RESULTS: High focal arterial FAPI uptake (FAPI +) was recorded in 64/69 (92.8%) scans in 800 sites, of which 377 (47.1%) exhibited concordant vessel wall calcification. The number of FAPI + sites per patient and (FAPI +)-derived target-to-background ratio (TBR) correlated significantly with the number of calcified plaques (FAPI + number: r = 0.45, P < 0.01; TBR: r = - 0.26, P = 0.04), calcified plaque thickness (FAPI + number: r = 0.33, P < 0.01; TBR: r = - 0.29, P = 0.02), and calcification circumference (FAPI + number: r = 0.34, P < 0.01; TBR: r = - 0.26, P = 0.04). In univariate analysis, only body mass index was significantly associated with the number of FAPI + sites (OR 1.06; 95% CI, 1.02 - 1.12, P < 0.01). The numbers of FAPI + sites and FAPI + TBR, however, were not associated with other investigated CVRFs in univariate and multivariate regression analyses. Image noise, however, showed significant correlations with FAPI + TBR (r = 0.30) and the number of FAPI + sites (r = 0.28; P = 0.02, respectively). In addition, there was no significant interaction between FAP-positive tumor burden and arterial wall FAPI uptake (P ≥ 0.13). CONCLUSION: [68 Ga]Ga-FAPI-04 PET identifies arterial wall lesions and is linked to marked calcification and overall calcified plaque burden, but is not consistently associated with cardiovascular risk. Apparent wall uptake may be partially explained by image noise.


Asunto(s)
Enfermedades Cardiovasculares , Placa Aterosclerótica , Quinolinas , Calcificación Vascular , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Enfermedades Cardiovasculares/diagnóstico por imagen , Factores de Riesgo , Placa Aterosclerótica/diagnóstico por imagen , Placa Aterosclerótica/metabolismo , Factores de Riesgo de Enfermedad Cardiaca , Calcificación Vascular/diagnóstico por imagen , Imagen Molecular , Fibroblastos/metabolismo , Radioisótopos de Galio , Fluorodesoxiglucosa F18
9.
Resusc Plus ; 14: 100373, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36935818

RESUMEN

Background: Every year, large numbers of individuals are present or provide first aid in situations involving out-of-hospital cardiac arrest, injuries, or suicides. Little is known about the impact of providing first aid or witnessing a first aid situation, but research indicates that many first aid providers (FAP) experience persistent psychological difficulties. Here we aimed to assess the level of psychological impact of being a FAP. Methods: In this retrospective study, FAP attending follow-up were asked to complete the International Trauma Questionnaire (ITQ), which is a self-report diagnostic measure of post-traumatic stress disorder (PTSD) and complex post-traumatic stress disorder (CPTSD). We recorded endorsement of a symptom or functional impairment (score ≥ 2/4 on at least one of 18 items). Results: Of the 102 FAP in this study, 86 (84%) showed endorsement of a symptom or functional impairment. Common symptoms/functional impairments included being super-alert, watchful, or on guard; having powerful mental images; avoiding internal reminders or memories; and being affected in important parts of one's life. One-third had affected ability to work. Of the FAPs who attended follow-up more than one month after the incident (n = 32), 19% met the criteria for PTSD or CPTSD. Conclusions: The majority of FAPs have endorsement of a symptom or functional impairment. Some FAPs fulfil the criteria of PTSD. We suggest that follow-up should be offered by the EMS to all FAPs involved in incidents with an unconscious patient.

10.
Vaccines (Basel) ; 11(2)2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36851185

RESUMEN

(1) Background: The oral vaccination of free-roaming dogs against rabies has been developed as a promising complementary tool for mass dog vaccination. However, no oral rabies vaccine has provided efficacy data in dogs according to international standards. (2) Methods: To test the immunogenicity and efficacy of the third-generation oral rabies virus vaccine strain, SPBN GASGAS, in domestic dogs, dogs were offered an egg-flavoured bait containing 3.0 mL of the vaccine (107.5 FFU/mL) or a placebo egg-flavoured bait. Subsequently, these 25 vaccinated and 10 control animals were challenged approximately 6 months later with a dog rabies virus isolate. Blood samples were collected at different time points postvaccination and examined by ELISA and RFFIT. (3) Results: All but 1 of the 25 vaccinated dogs survived the challenge infection; meanwhile, all 10 control dogs succumbed to rabies. The serology results showed that all 25 vaccinated dogs seroconverted in ELISA (>40% PB); meanwhile, only 13 of the 25 vaccinated dogs tested seropositive ≥ 0.5 IU/mL) in RFFIT. (4) Conclusions: The SPBN GASGAS rabies virus vaccine meets the efficacy requirements for live oral rabies vaccines as laid down by the European Pharmacopoeia and the WOAH Terrestrial Manual. SPBN GASGAS already fulfilled the safety requirements for oral rabies vaccines targeted at dogs. Hence, the egg-flavoured bait containing SPBN GASGAS is the first oral vaccine bait that complies with WOAH recommendations for the intended use of oral vaccination of free-roaming dogs against rabies.

11.
Materials (Basel) ; 16(2)2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36676423

RESUMEN

Laser structuring is by far the most investigated metal surface-pretreatment method for creating adhesion in polymer-metal hybrids. Especially, cone-like protrusions show excellent wetting behaviour as well as high compound strength. However, the processing time is extremely high. Therefore, this paper assesses a process strategy for creating pin structures with scalable height by single pulse drilling with an Nd/YVO4 nanosecond laser system on EN AW-6082 aluminium alloy. The strength testing is carried out by butt-bonded hollow cylinder torsion. The samples are manufactured by heat-conduction thermal joining with polyamide 6. Ten different surface structures with two different ablation diameters are investigated and compared to cone-like protrusions in terms of processing time, wetting behaviour, shear strength and fracture behaviour. The experimental results show that pulse drilling pins structures with high aspect ratio reach-strength values close to cone-like protrusions but with 31 times higher processing rate.

12.
Magn Reson Med ; 89(5): 2024-2047, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36695294

RESUMEN

This article focuses on clinical applications of arterial spin labeling (ASL) and is part of a wider effort from the International Society for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group to update and expand on the recommendations provided in the 2015 ASL consensus paper. Although the 2015 consensus paper provided general guidelines for clinical applications of ASL MRI, there was a lack of guidance on disease-specific parameters. Since that time, the clinical availability and clinical demand for ASL MRI has increased. This position paper provides guidance on using ASL in specific clinical scenarios, including acute ischemic stroke and steno-occlusive disease, arteriovenous malformations and fistulas, brain tumors, neurodegenerative disease, seizures/epilepsy, and pediatric neuroradiology applications, focusing on disease-specific considerations for sequence optimization and interpretation. We present several neuroradiological applications in which ASL provides unique information essential for making the diagnosis. This guidance is intended for anyone interested in using ASL in a routine clinical setting (i.e., on a single-subject basis rather than in cohort studies) building on the previous ASL consensus review.


Asunto(s)
Accidente Cerebrovascular Isquémico , Enfermedades Neurodegenerativas , Humanos , Niño , Angiografía por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodos , Marcadores de Spin , Perfusión , Circulación Cerebrovascular
14.
Clin Nucl Med ; 48(1): 35-42, 2023 Jan 01.
Artículo en Alemán, Inglés | MEDLINE | ID: mdl-36354691

RESUMEN

PURPOSE: We aimed to determine the impact of fibroblast activation protein inhibitor (FAPI)-directed molecular imaging on staging and therapeutic management in patients affected with digestive system tumors when compared with guideline-compatible imaging (GCI). PATIENTS AND METHODS: Thirty-two patients with tumors of the digestive system were included: colon adenocarcinoma, 2/32 (6.3%); hepatocellular carcinoma (HCC), 6/32 (18.8%); pancreatic duct adenocarcinoma (PDAC), 6/32 (18.8%), and gastroenteropancreatic neuroendocrine neoplasms, 18/32 (56.3%). All patients underwent GCI and 68 Ga-FAPI-04 PET/CT within median 4 days. Staging outcomes and subsequent treatment decisions were compared between GCI and 68 Ga-FAPI-04 PET/CT. RESULTS: Compared with GCI, 68 Ga-FAPI-04 PET/CT led to staging changes in 15/32 patients (46.9%). Among those, downstaging was recorded in 3/15 cases (20.0%) and upstaging in the remaining 12/15 patients (HCC, 4/12 [33.3%]; PDAC, 4/12 [33.3%]; neuroendocrine neoplasms, 3/12 [25%]; colon adenocarcinoma, 1/12 [8.3%]). Therapeutic management was impacted in 8/32 patients (25.0%), including 4 instances of major and 4 instances of minor therapeutic changes. The highest proportion of treatment modifications was observed in patients diagnosed with PDAC and HCC in 6/8 (75%). CONCLUSIONS: In patients affected with digestive system tumors, 68 Ga-FAPI-04 PET/CT resulted in staging changes in more than 46% and therapeutic modifications in 25% of the cases, in particular in patients with HCC and PDAC. In clinical routine, such findings may favor a more widespread adoption of FAP-directed imaging in those tumor types.


Asunto(s)
Adenocarcinoma , Carcinoma Hepatocelular , Carcinoma Ductal Pancreático , Neoplasias del Colon , Neoplasias del Sistema Digestivo , Neoplasias Gastrointestinales , Neoplasias Hepáticas , Tumores Neuroendocrinos , Neoplasias Pancreáticas , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/terapia , Radioisótopos de Galio , Neoplasias del Sistema Digestivo/diagnóstico por imagen , Neoplasias del Sistema Digestivo/terapia , Tumores Neuroendocrinos/diagnóstico por imagen , Tumores Neuroendocrinos/terapia , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/terapia , Fluorodesoxiglucosa F18
15.
J Int Bus Stud ; 53(6): 1282-1306, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35789665

RESUMEN

In this paper, we broaden the conceptualization of institutions beyond the nation-state and develop the concept of an institutional triality that represents two national institutional environments and the supranational level. While much of international business (IB) research has focused on national institutions and the differences between them, little attention and theorizing has been dedicated to the supranational institutions that form an integral part of the global institutional ecosystem. First, we conduct an interdisciplinary bibliometric survey on supranational institutions and a qualitative review of the central publications. Second, we initiate theory building and conceptualize supranational institutions from an IB point of view, distinguish them from related IB concepts, and discuss the conceptual properties of supranational institutions that are most relevant for MNCs. Building on these distinctions and properties, we provide a conceptual framework for understanding supranational institutions in the institutional triality. Third, we provide avenues for IB research building on the delineations, the conceptual properties, and the conceptual framework. Supplementary Information: The online version contains supplementary material available at 10.1057/s41267-022-00537-3.


Dans cet article, nous élargissons la conceptualisation des institutions au-delà de l'État-nation et développons le concept de trialité institutionnelle qui représente deux environnements institutionnels nationaux et le niveau supranational. Alors qu'une grande partie de la recherche en affaires internationales (International Business - IB) s'est focalisée sur les institutions nationales et les différences entre elles, peu d'attention et d'effort de théorisation sont consacrés aux institutions supranationales qui font partie intégrante de l'écosystème institutionnel global. Dans un premier temps, nous réalisons une enquête bibliométrique interdisciplinaire sur les institutions supranationales et une revue qualitative des principales publications. Ensuite, nous commençons la construction théorique et conceptualisons les institutions supranationales dans une perspective de l'IB. Nous les distinguons des concepts connexes de l'IB et discutons des propriétés conceptuelles des institutions supranationales qui sont les plus pertinentes pour les entreprises multinationales. Nous appuyant sur ces distinctions et ces propriétés, nous apportons un cadre conceptuel permettant de comprendre les institutions supranationales dans la trialité institutionnelle. Enfin, nous proposons des pistes de recherche en IB en partant sur les délimitations, les propriétés conceptuelles et le cadre conceptuel.


En este trabajo ampliamos la conceptualización de las instituciones más allá del estado nación y desarrollamos el concepto de trialidad institucional que representa dos entornos institucionales nacionales y el nivel supranacional. Mientras que mucha de la investigación en negocios internacionales se ha enfocado en las instituciones nacionales y las diferencias entre ellas, poca atención y teorización se ha dedicado a las instituciones supranacionales que forman parte integral del ecosistema institucional global. Primero, llevamos a cabo un sondeo bibliométrico interdisciplinario sobre las instituciones supranacionales y una revisión cualitativa de las publicaciones centrales. Segundo, iniciamos una construcción teórica y a conceptualizar las instituciones supranacionales desde el punto de vista de negocios internacionales, diferenciándolas de otros conceptos relacionados en negocios internacionales, y discutimos las propiedades conceptuales de las instituciones supranacionales que son más relevantes para las empresas multinacionales. En base en estas diferencias y propiedades, proporcionamos un marco conceptual para entender las instituciones supranacionales en la trialidad instituciona. Tercero, proporcionamos posibilidades para la investigación en negocios internacionales sobre las delimitaciones, las propiedades conceptuales, y el marco conceptual.


Neste artigo, ampliamos a conceituação de instituições para além do estado-nação e desenvolvemos o conceito de uma trialidade institucional que representa dois ambientes institucionais nacionais e o nível supranacional. Embora grande parte da pesquisa em negócios internacionais (IB) tenha se concentrado em instituições nacionais e nas diferenças entre elas, pouca atenção e teorização são dedicadas às instituições supranacionais que formam uma parte intrínseca do ecossistema institucional global. Primeiramente, realizamos um levantamento bibliométrico interdisciplinar em instituições supranacionais e uma revisão qualitativa das publicações centrais. Em segundo lugar, iniciamos a construção de teoria e conceituamos instituições supranacionais sob o ponto de vista de IB, distinguimo-las de conceitos relacionados a IB e discutimos as propriedades conceituais de instituições supranacionais que são mais relevantes para MNCs. Com base nessas diferenças e propriedades, fornecemos um modelo conceitual para entender as instituições supranacionais na trialidade institucional. Terceiro, fornecemos caminhos para construção de pesquisa em IB sobre delineações, propriedades conceituais e modelo conceitual.

16.
Cancers (Basel) ; 14(11)2022 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-35681588

RESUMEN

(1) Background: We aimed to quantitatively investigate [68Ga]Ga-FAPI-04 uptake in normal organs and to assess a relationship with the extent of FAPI-avid tumor burden. (2) Methods: In this single-center retrospective analysis, thirty-four patients with solid cancers underwent a total of 40 [68Ga]Ga-FAPI-04 PET/CT scans. Mean standardized uptake values (SUVmean) for normal organs were established by placing volumes of interest (VOIs) in the heart, liver, spleen, pancreas, kidneys, and bone marrow. Total tumor burden was determined by manual segmentation of tumor lesions with increased uptake. For tumor burden, quantitative assessment included maximum SUV (SUVmax), tumor volume (TV), and fractional tumor activity (FTA = TV × SUVmean). Associations between uptake in normal organs and tumor burden were investigated by applying Spearman's rank correlation coefficient. (3) Results: Median SUVmean values were 2.15 in the pancreas (range, 1.05-9.91), 1.42 in the right (range, 0.57-3.06) and 1.41 in the left kidney (range, 0.73-2.97), 1.2 in the heart (range, 0.46-2.59), 0.86 in the spleen (range, 0.55-1.58), 0.65 in the liver (range, 0.31-2.11), and 0.57 in the bone marrow (range, 0.26-0.94). We observed a trend towards significance for uptake in the myocardium and tumor-derived SUVmax (ρ = 0.29, p = 0.07) and TV (ρ = -0.30, p = 0.06). No significant correlation was achieved for any of the other organs: SUVmax (ρ ≤ 0.1, p ≥ 0.42), TV (ρ ≤ 0.11, p ≥ 0.43), and FTA (ρ ≤ 0.14, p ≥ 0.38). In a sub-analysis exclusively investigating patients with high tumor burden, significant correlations of myocardial uptake with tumor SUVmax (ρ = 0.44; p = 0.03) and tumor-derived FTA with liver uptake (ρ = 0.47; p = 0.02) were recorded. (4) Conclusions: In this proof-of-concept study, quantification of [68Ga]Ga-FAPI-04 PET showed no significant correlation between normal organs and tumor burden, except for a trend in the myocardium. Those preliminary findings may trigger future studies to determine possible implications for treatment with radioactive FAP-targeted drugs, as higher tumor load or uptake may not lead to decreased doses in the majority of normal organs.

17.
Eur J Nucl Med Mol Imaging ; 49(12): 4133-4144, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35674738

RESUMEN

A growing body of literature reports on the upregulation of C-X-C motif chemokine receptor 4 (CXCR4) in a variety of cancer entities, rendering this receptor as suitable target for molecular imaging and endoradiotherapy in a theranostic setting. For instance, the CXCR4-targeting positron emission tomography (PET) agent [68 Ga]PentixaFor has been proven useful for a comprehensive assessment of the current status quo of solid tumors, including adrenocortical carcinoma or small-cell lung cancer. In addition, [68 Ga]PentixaFor has also provided an excellent readout for hematological malignancies, such as multiple myeloma, marginal zone lymphoma, or mantle cell lymphoma. PET-based quantification of the CXCR4 capacities in vivo allows for selecting candidates that would be suitable for treatment using the theranostic equivalent [177Lu]/[90Y]PentixaTher. This CXCR4-directed theranostic concept has been used as a conditioning regimen prior to hematopoietic stem cell transplantation and to achieve sufficient anti-lymphoma/-tumor activity in particular for malignant tissues that are highly sensitive to radiation, such as the hematological system. Increasing the safety margin, pretherapeutic dosimetry is routinely performed to determine the optimal activity to enhance therapeutic efficacy and to reduce off-target adverse events. The present review will provide an overview of current applications for CXCR4-directed molecular imaging and will introduce the CXCR4-targeted theranostic concept for advanced hematological malignancies.


Asunto(s)
Complejos de Coordinación , Neoplasias Hematológicas , Linfoma , Mieloma Múltiple , Adulto , Humanos , Péptidos Cíclicos , Medicina de Precisión , Receptores CXCR4 , Tomografía Computarizada por Rayos X
18.
Parasitol Res ; 121(7): 2079-2086, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35585258

RESUMEN

Sika deer (Cervus nippon), which are native to the Japanese islands and the adjacent mainland of eastern Asia, have been introduced into Europe and established free-ranging populations in several countries. Various Sarcocystis species have been identified recently from farmed "mainland sika" deer in Lithuania and native "Japanese sika" deer in Japan. To study the distribution, prevalence and intensity of Sarcocystis infection in free-ranging sika deer outside of their natural range heart and/or diaphragm samples of 311 animals from nine populations in Germany and Austria were examined by histology.Overall, sarcocysts were detected in either heart or diaphragm of 107/311 deer (34.4%) with prevalence ranging roughly from 5 to 50% among the populations. Considering the 263 animals with both heart and diaphragm available, prevalence varied significantly (p < 0.0001) among calves (20.2%), yearlings (40.3%), and adult deer (49.1%) but did not differ between male and female deer (48.3% vs. 43.7%; p = 0.6483). Occurrence of sarcocysts in heart vs. diaphragm indicated a marginal difference (27.8% vs. 20.9%; p = 0.0839). Intensity of infection in all but one heart positive and all diaphragm positive animals was low (< 10 sarcocysts per square centimeter muscle cut). While heart sarcocyst counts of yearlings and adult deer were higher than those of calves and were higher in male compared to female sika deer, diaphragm sarcocyst counts did not differ significantly between age groups and sexes. Sarcocystis infection was demonstrated at variable prevalence in sika deer in all populations but intensity is apparently low. Further studies are needed to identify the species of Sarcocystis infecting sika deer naturalized outside their natural range.


Asunto(s)
Ciervos , Sarcocystis , Sarcocistosis , Animales , Austria , Bovinos , Diafragma , Femenino , Japón , Masculino , Filogenia , Prevalencia , ARN Ribosómico 18S , Sarcocystis/genética , Sarcocistosis/epidemiología , Sarcocistosis/veterinaria
19.
Invest Radiol ; 57(7): 463-469, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35148536

RESUMEN

OBJECTIVES: Fat quantification by dual-energy computed tomography (DECT) provides contrast-independent objective results, for example, on hepatic steatosis or muscle quality as parameters of prognostic relevance. To date, fat quantification has only been developed and used for source-based DECT techniques as fast kVp-switching CT or dual-source CT, which require a prospective selection of the dual-energy imaging mode.It was the purpose of this study to develop a material decomposition algorithm for fat quantification in phantoms and validate it in vivo for patient liver and skeletal muscle using a dual-layer detector-based spectral CT (dlsCT), which automatically generates spectral information with every scan. MATERIALS AND METHODS: For this feasibility study, phantoms were created with 0%, 5%, 10%, 25%, and 40% fat and 0, 4.9, and 7.0 mg/mL iodine, respectively. Phantom scans were performed with the IQon spectral CT (Philips, the Netherlands) at 120 kV and 140 kV and 3 T magnetic resonance (MR) (Philips, the Netherlands) chemical-shift relaxometry (MRR) and MR spectroscopy (MRS). Based on maps of the photoelectric effect and Compton scattering, 3-material decomposition was done for fat, iodine, and phantom material in the image space.After written consent, 10 patients (mean age, 55 ± 18 years; 6 men) in need of a CT staging were prospectively included. All patients received contrast-enhanced abdominal dlsCT scans at 120 kV and MR imaging scans for MRR. As reference tissue for the liver and the skeletal muscle, retrospectively available non-contrast-enhanced spectral CT data sets were used. Agreement between dlsCT and MR was evaluated for the phantoms, 3 hepatic and 2 muscular regions of interest per patient by intraclass correlation coefficients (ICCs) and Bland-Altman analyses. RESULTS: The ICC was excellent in the phantoms for both 120 kV and 140 kV (dlsCT vs MRR 0.98 [95% confidence interval (CI), 0.94-0.99]; dlsCT vs MRS 0.96 [95% CI, 0.87-0.99]) and in the skeletal muscle (0.96 [95% CI, 0.89-0.98]). For log-transformed liver fat values, the ICC was moderate (0.75 [95% CI, 0.48-0.88]). Bland-Altman analysis yielded a mean difference of -0.7% (95% CI, -4.5 to 3.1) for the liver and of 0.5% (95% CI, -4.3 to 5.3) for the skeletal muscle. Interobserver and intraobserver agreement were excellent (>0.9). CONCLUSIONS: Fat quantification was developed for dlsCT and agreement with MR techniques demonstrated for patient liver and muscle. Hepatic steatosis and myosteatosis can be detected in dlsCT scans from clinical routine, which retrospectively provide spectral information independent of the imaging mode.


Asunto(s)
Yodo , Tomografía Computarizada por Rayos X , Adulto , Anciano , Humanos , Masculino , Persona de Mediana Edad , Fantasmas de Imagen , Estudios Prospectivos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos
20.
World Neurosurg ; 157: 152-158, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34673240

RESUMEN

In neurosurgery, an exact delineation of functional areas is of great interest to spare important regions to ensure the best possible outcome for the patient (i.e., maximum removal while maintaining the highest possible quality of life). Preoperative imaging is routinely performed, including the visualization of not only structural but also functional information. During surgery, however, brain shift can occur, leading to an offset between the previously defined and the real position. Real-time imaging during the procedure is therefore desired to obtain this information while performing surgery. In this study 15 patients suffering from glioblastoma multiforme were included. These patients underwent structural and perfusion imaging using arterial spin labeling during the procedure. The latter has been used for gathering information about tumor residual perfusion. However, special postprocessing of this data allows for additional mapping of resting state networks and is intended to be used to gather deeper insights to aid the surgeon in planning the procedure. The data of each patient could be successfully postprocessed and used to map different resting state networks alongside the default mode network. On the basis of this study, it is feasible to use the information obtained from perfusion imaging to visualize not only vascular signal but also functional activation of resting state networks without acquiring any additional data besides the already available information. This may help guide the neurosurgeon in real time to adjust the surgical plan.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Red en Modo Predeterminado/diagnóstico por imagen , Glioblastoma/diagnóstico por imagen , Neuroimagen/métodos , Procedimientos Neuroquirúrgicos/métodos , Imagen de Perfusión/métodos , Adulto , Anciano , Neoplasias Encefálicas/cirugía , Femenino , Glioblastoma/cirugía , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad
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