Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 106
Filtrar
1.
Eur J Pharm Biopharm ; 203: 114437, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39122053

RESUMO

Tuberculosis (TB) has been and still is a global emergency for centuries. Prevention of disease through vaccination would have a major impact on disease prevalence, but the only available current vaccine, BCG, has insufficient impact. In this article, a novel subunit vaccine against TB was developed, using the Ag85B-ESAT6-Rv2034 fusion antigen, two adjuvants - CpG and MPLA, and a cationic pH-sensitive liposome as a delivery system, representing a new TB vaccine delivery strategy not previously reported for TB. In vitro in human dendritic cells (DCs), the adjuvanted formulation induced a significant increase in the production of (innate) cytokines and chemokines compared to the liposome without additional adjuvants. In vivo, the new vaccine administrated subcutaneously significantly reduced Mycobacterium tuberculosis (Mtb) bacterial load in the lungs and spleens of mice, significantly outperforming results from mice vaccinated with the antigen mixed with adjuvants without liposomes. In-depth analysis underpinned the vaccine's effectiveness in terms of its capacity to induce polyfunctional CD4+ and CD8+ T-cell responses, both considered essential for controlling Mtb infection. Also noteworthy was the differential abundance of various CD69+ B-cell subpopulations, which included IL17-A-producing B-cells. The vaccine stimulated robust antigen-specific antibody titers, further extending its potential as a novel protective agent against TB.


Assuntos
Adjuvantes Imunológicos , Lipossomos , Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Vacinas de Subunidades Antigênicas , Animais , Vacinas contra a Tuberculose/administração & dosagem , Vacinas contra a Tuberculose/imunologia , Mycobacterium tuberculosis/imunologia , Camundongos , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Humanos , Feminino , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Concentração de Íons de Hidrogênio , Tuberculose/prevenção & controle , Tuberculose/imunologia , Camundongos Endogâmicos C57BL , Células Dendríticas/imunologia , Cátions , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/administração & dosagem , Citocinas/metabolismo , Linfócitos T CD8-Positivos/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Linfócitos T CD4-Positivos/imunologia , Carga Bacteriana
2.
Placenta ; 154: 60-65, 2024 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-38901306

RESUMO

OBJECTIVE: Non-invasive prenatal testing (NIPT) investigates placental DNA and may detect confined placental mosaicism (CPM). The aim of this study was to confirm CPM in the term placenta in cases with abnormal NIPT but normal follow-up cytogenetic studies of fetus and mother. Additionally we examined the distribution of abnormal cells over the placenta. METHODS: Four chorionic villus (CV) biopsies from four placental quadrants were requested in cases where CPM was assumed. Both cell lineages of the CV, cytotrophoblast (CTB) and mesenchymal core (MC), were analyzed separately with SNP array. RESULTS: The chromosome aberration was confirmed in 67 % of the placentas. Three quarters of the CTB and MC biopsies from these mosaic placentas were uniformly normal (57 %) or abnormal (20 %), and a minority showed mosaicism. Among 16 cases of CPM where first trimester CV were examined as well, 11 had chromosomally normal results during pregnancy. DISCUSSION: Cytogenetic investigations of term placental biopsies suspected to be affected with CPM did not reveal the chromosome aberration in one third of the placentas. This is caused by the patchy pattern in which chromosomally abnormal cells are distributed over the placenta with the majority of the biopsies being uniformly normal. Further CPM research, including its clinical impact, requires the analysis of more than four biopsies to get insight into the extent of the affected part. Moreover, a subset of CPM type 1 and 3 seems to be only detectable with NIPT and not with first trimester CVS.


Assuntos
Aberrações Cromossômicas , Mosaicismo , Placenta , Humanos , Feminino , Gravidez , Placenta/patologia , Adulto , Teste Pré-Natal não Invasivo/métodos , Doenças Placentárias/patologia , Doenças Placentárias/genética
3.
J Cyst Fibros ; 23(3): 388-397, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38388234

RESUMO

After three publications defining an updated guidance on the diagnostic criteria for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (pwCFTR-RDs), establishing its relationship to CFTR-dysfunction and describing the individual disorders, this fourth and last paper in the series addresses some critical challenges facing health care providers and pwCFTR-RD. Topics included are: 1) benefits and obstacles to collect data from pwCFTR-RD are discussed, together with the opportunity to integrate them into established CF-registries; 2) the potential of infants designated CRMS/CFSPID to develop a CFTR-RD and how to communicate this information; 3) a description of the challenges in genetic counseling, with particular regard to phenotypic variability, unknown long-term evolution, CFTR testing and pregnancy termination 4) a proposal for the assessment of potential barriers to the implementation and dissemination of the produced documents to health care professionals involved in the care of pwCFTR-RD and a process to monitor the implementation of the CFTR-RD recommendations; 5) clinical trials investigating the efficacy of CFTR modulators in CFTR-RD and how endpoints and outcomes might be adapted to the heterogeneity of these disorders.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Fibrose Cística , Padrão de Cuidado , Humanos , Fibrose Cística/terapia , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Aconselhamento Genético , Testes Genéticos/métodos , Recém-Nascido
4.
Sci Rep ; 13(1): 14485, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37660180

RESUMO

We have used the LOw-Frequency ARray (LOFAR) to search for the growing tip of an intra-cloud (IC) positive leader. Even with our most sensitive beamforming method, where we coherently add the signals of about 170 antenna pairs, we were not able to detect any emission from the tip. Instead, we put constraints on the emissivity of very-high frequency (VHF) radiation from the tip at 0.5 pJ/MHz at 60 MHz, integrated over 100 ns. The limit is independent on whether this emission is in the form of short pulses or continuously radiating. The non-observation of VHF radiation from intra-cloud positive leaders implies that they proceed in an extremely gradual process, which is in sharp contrast with the observations of other parts of a lightning discharge.

5.
Earth Space Sci ; 9(4): e2021EA001958, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35865721

RESUMO

When a lightning flash is propagating in the atmosphere it is known that especially the negative leaders emit a large number of very high frequency (VHF) radio pulses. It is thought that this is due to streamer activity at the tip of the growing negative leader. In this work, we have investigated the dependence of the strength of this VHF emission on the altitude of such emission for two lightning flashes as observed by the Low Frequency ARray (LOFAR) radio telescope. We find for these two flashes that the extracted amplitude distributions are consistent with a power-law, and that the amplitude of the radio emissions decreases very strongly with source altitude, by more than a factor of 2 from 1 km altitude up to 5 km altitude. In addition, we do not find any dependence on the extracted power-law with altitude, and that the extracted power-law slope has an average around 3, for both flashes.

6.
Mol Genet Metab ; 135(2): 163-169, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35033446

RESUMO

BACKGROUND: Enzyme replacement therapy (ERT) slows disease progression of Fabry disease (FD), especially when initiated before the onset of irreversible organ damage. However, with the clinically asymptomatic progression of renal, cardiac and cerebral disease manifestations spanning decades, optimal timing of ERT initiation remains unclear. METHODS: In this cross-sectional retrospective study, seven male FD patients with a classical disease phenotype (cFD) who started treatment with agalsidase-beta in childhood were evaluated after 10 years of treatment (median age at evaluation 24 years, range 14-26). Cardiac imaging (echocardiography and MRI), electrophysiological and biochemical data of these patients were compared to those of untreated male cFD patients (n = 23, median age 22 years, range 13-27). RESULTS: Albuminuria was less common and less severe in treated patients (albumin to creatinine ratio, ACR 0-8.8 mg/mmol, median 0.4) compared to untreated patients (ACR 0-248 mg/mmol, median 3.7, p = 0.02). The treated group had a lower left ventricular mass, measured using echocardiography (median 80 g/m2 versus 94 g/m2, p = 0.02) and MRI (median 53 g/m2 versus 68 g/m2, p = 0.02). Myocardial fibrosis was absent in all included patients. eGFR was normal in all treated patients whereas 7/23 (30%) of untreated patients had abnormal eGFR. Cerebral manifestations did not differ. CONCLUSIONS: Start of treatment with ERT before age 16, in male cFD patients is associated with reduced occurrence of renal and cardiac manifestations of FD, as assessed by intermediate endpoints. Confirmation that this approach delays or even prevents renal failure and cardiac events requires another decade of follow-up.


Assuntos
Doença de Fabry , Criança , Estudos Transversais , Progressão da Doença , Terapia de Reposição de Enzimas/métodos , Doença de Fabry/complicações , Humanos , Masculino , Estudos Retrospectivos , alfa-Galactosidase/efeitos adversos , alfa-Galactosidase/genética
7.
Tijdschr Psychiatr ; 63(10): 711-716, 2021.
Artigo em Holandês | MEDLINE | ID: mdl-34757609

RESUMO

BACKGROUND: The waiting list of the expertise center euthanasia (EE) in the Netherlands for patients requesting euthanasia on the basis of psychiatric suffering has increased to two years in a short space of time. AIM: Clarity about the causes and direct consequences of the EE waiting list and an answer to the question: what now? METHOD: We analyzed the EE waiting list based on various media reports, annual reports from the EE and scientific studies. RESULTS: The EE waiting list arose because, on the one hand, the demand for euthanasia among patients with a mental illness has increased, while on the other hand, the willingness to perform euthanasia among psychiatrists appears to be declining. The reasons for both trends seem multifactorial. The direct consequence of the waiting list is that patients with a mental illness have less access to euthanasia, which in itself can also have harmful and protective consequences. CONCLUSION: The EE waiting list is the result of an increasing number of requests and an apparent decrease in psychiatrists' willingness to perform euthanasia. In response to this situation, roughly three ways forward are conceivable: first the mental health care sector can assign itself a more active role in the field of euthanasia, second a further demedicalisation of the end of life is possible, or third a choice can be an amendment to EE's referral procedure. All of these options have potential pros and cons.


Assuntos
Eutanásia , Transtornos Mentais , Psiquiatria , Humanos , Países Baixos , Encaminhamento e Consulta , Listas de Espera
8.
Sci Rep ; 11(1): 19634, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34608194

RESUMO

The persistent increase of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) infections negatively impacts Tuberculosis treatment outcomes. Host-directed therapies (HDT) pose an complementing strategy, particularly since Mtb is highly successful in evading host-defense by manipulating host-signaling pathways. Here, we screened a library containing autophagy-modulating compounds for their ability to inhibit intracellular Mtb-bacteria. Several active compounds were identified, including two drugs of the diphenylbutylpiperidine-class, Fluspirilene and Pimozide, commonly used as antipsychotics. Both molecules inhibited intracellular Mtb in pro- as well as anti-inflammatory primary human macrophages in a host-directed manner and synergized with conventional anti-bacterials. Importantly, these inhibitory effects extended to MDR-Mtb strains and the unrelated intracellular pathogen, Salmonella enterica serovar Typhimurium (Stm). Mechanistically Fluspirilene and Pimozide were shown to regulate autophagy and alter the lysosomal response, partly correlating with increased bacterial localization to autophago(lyso)somes. Pimozide's and Fluspirilene's efficacy was inhibited by antioxidants, suggesting involvement of the oxidative-stress response in Mtb growth control. Furthermore, Fluspirilene and especially Pimozide counteracted Mtb-induced STAT5 phosphorylation, thereby reducing Mtb phagosome-localized CISH that promotes phagosomal acidification. In conclusion, two approved antipsychotic drugs, Pimozide and Fluspirilene, constitute highly promising and rapidly translatable candidates for HDT against Mtb and Stm and act by modulating the autophagic/lysosomal response by multiple mechanisms.


Assuntos
Antibacterianos/farmacologia , Antipsicóticos/farmacologia , Antituberculosos/farmacologia , Reposicionamento de Medicamentos , Mycobacterium tuberculosis/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Linhagem Celular , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ensaios de Triagem em Larga Escala , Humanos , Lisossomos/metabolismo , Testes de Sensibilidade Microbiana , Modelos Biológicos , Fagossomos/metabolismo , Pimozida/farmacologia , Infecções por Salmonella/tratamento farmacológico , Infecções por Salmonella/microbiologia , Bibliotecas de Moléculas Pequenas , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia
9.
Earth Space Sci ; 8(7): e2020EA001523, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34435079

RESUMO

Since their introduction 22 years ago, lightning mapping arrays (LMA) have played a central role in the investigation of lightning physics. Even in recent years with the proliferation of digital interferometers and the introduction of the LOw Frequency ARray (LOFAR) radio telescope, LMAs still play an important role in lightning science. LMA networks use a simple windowing technique that records the highest pulse in either 80 µs or 10 µs fixed windows in order to apply a time-of-arrival location technique. In this work, we develop an LMA-emulator that uses lightning data recorded by LOFAR to simulate an LMA, and we use it to test three new styles of pulse windowing. We show that they produce very similar results as the more traditional LMA windowing, implying that LMA lightning mapping results are relatively independent of windowing technique. In addition, each LMA station has its GPS-conditioned clock. While the timing accuracy of GPS receivers has improved significantly over the years, they still significantly limit the timing measurements of the LMA. Recently, new time-of-arrival techniques have been introduced that can be used to self-calibrate systematic offsets between different receiving stations. Applying this calibration technique to a set of data with 32 ns uncertainty, observed by the Colorado LMA, improves the timing uncertainty to 19 ns. This technique is not limited to LMAs and could be used to help calibrate future multi-station lightning interferometers.

10.
Sci Rep ; 11(1): 16256, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376724

RESUMO

The common phenomenon of lightning still harbors many secrets such as what are the conditions for lightning initiation and what is driving the discharge to propagate over several tens of kilometers through the atmosphere forming conducting ionized channels called leaders. Since lightning is an electric discharge phenomenon, there are positively and negatively charged leaders. In this work we report on measurements made with the LOFAR radio telescope, an instrument primarily build for radio-astronomy observations. It is observed that a negative leader rather suddenly changes, for a few milliseconds, into a mode where it radiates 100 times more VHF power than typical negative leaders after which it spawns a large number of more typical negative leaders. This mode occurs during the initial stage, soon after initiation, of all lightning flashes we have mapped (about 25). For some flashes this mode occurs also well after initiation and we show one case where it is triggered twice, some 100 ms apart. We postulate that this is indicative of a small (order of 5 km[Formula: see text]) high charge pocket. Lightning thus appears to be initiated exclusively in the vicinity of such a small but dense charge pocket.

11.
Parkinsonism Relat Disord ; 89: 176-185, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34362669

RESUMO

INTRODUCTION: To guide the neurologist and neurophysiologist with interpretation and implementation of clinical neurophysiological examinations, we aim to provide a systematic review on evidence of electrophysiological features used to differentiate between hyperkinetic movement disorders. METHODS: A PRISMA systematic search and QUADAS quality evaluation has been performed in PubMed to identify diagnostic test accuracy studies comparing electromyography and accelerometer features. We included papers focusing on tremor, dystonia, myoclonus, chorea, tics and ataxia and their functional variant. The features were grouped as 1) basic features (e.g., amplitude, frequency), 2) the influence of tasks on basic features (e.g., entrainment, distraction), 3) advanced analyses of multiple signals, 4) and diagnostic tools combining features. RESULTS: Thirty-eight cross-sectional articles were included discussing tremor (n = 28), myoclonus (n = 5), dystonia (n = 5) and tics (n = 1). Fifteen were rated as 'high quality'. In tremor, the basic and task-related features showed great overlap between clinical tremor syndromes, apart from rubral and enhanced physiological tremor. Advanced signal analyses were best suited for essential, parkinsonian and functional tremor, and cortical, non-cortical and functional jerks. Combinations of electrodiagnostic features could identify essential, enhanced physiological and functional tremor. CONCLUSION: Studies into the diagnostic accuracy of electrophysiological examinations to differentiate between hyperkinetic movement disorders have predominantly been focused on clinical tremor syndromes. No single feature can differentiate between them all; however, a combination of analyses might improve diagnostic accuracy.


Assuntos
Acelerometria , Eletromiografia , Hipercinese/diagnóstico , Transtornos dos Movimentos/diagnóstico , Neurofisiologia/métodos , Estudos Transversais , Diagnóstico Diferencial , Distonia/diagnóstico , Humanos , Mioclonia/diagnóstico , Tiques/diagnóstico , Tremor/diagnóstico
12.
Tijdschr Psychiatr ; 63(2): 150-153, 2021.
Artigo em Holandês | MEDLINE | ID: mdl-33620729

RESUMO

Background Proactive psychiatry requires proactive psychiatric ethics. Aim To describe ethical considerations with regard to proactive psychiatry. Method Discussion of care ethics aimed at proactive psychiatric care. Results In this contribution, we plea for a proactive psychiatric ethics, stimulating and supporting healthcare professionals in working from a developmental and contextual perspective. We describe care ethics, and show that it is in line with the principles of proactive psychiatry. We address three issues related to the development of proactive psychiatry: the goals of care; identifying risk factors; and the division of responsibilities in mental healthcare. Conclusion Proactive psychiatric ethics can be useful in identifying and discussing ethical issues associated with proactive psychiatry and thus contribute to improving practice. Tijdschrift voor Psychiatrie 63(2021)2, 150-153.


Assuntos
Psiquiatria , Humanos , Psicoterapia
13.
Cancer Immunol Immunother ; 70(6): 1569-1581, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33225419

RESUMO

Targeted cancer therapy with monoclonal antibodies has proven successful for different cancer types but is limited by the availability of suitable antibody targets. CD43s, a unique sialylated form of CD43 expressed by hematologic malignancies, is a recently identified target and antibodies interacting with CD43s may have therapeutic potential against acute myeloid leukemia (AML) and myelodysplastic syndrome. CD43s is recognized by the human antibody AT1413, that was derived from a high-risk AML patient who successfully cleared leukemia after allogeneic stem cell transplantation. Here we observed that AT1413 binds also to certain non-hematopoietic tumor cells, particularly melanoma and breast cancer. AT1413 immune precipitated CD43s from melanoma cells confirming that it recognizes the same target on melanoma as on AML. AT1413 induced antibody-dependent cellular cytotoxicity against short-term cultured patient-derived melanoma samples. However, AT1413 was unable to affect the growth of melanoma cells in vivo. To increase the efficacy of AT1413 as a therapeutic antibody, we generated two different formats of bispecific T-cell engaging antibodies (TCEs): one binding bivalently (bTCE) and the other monovalently (knob-in-hole; KiH) to both CD43s and CD3ε. In vitro, these TCEs redirected T-cell cytotoxicity against melanoma cells with differences in potencies. To investigate their effects in vivo, we grafted mice that harbor a human immune system with the melanoma cell line A375. Treatment with both AT1413 bTCE and AT1413 KiH significantly reduced tumor outgrowth in these mice. These data indicate a broad therapeutic potential of AT1413 that includes AML and CD43s-expressing solid tumors that originate from CD43-negative tissues.


Assuntos
Anticorpos Biespecíficos/farmacologia , Anticorpos Monoclonais/farmacologia , Antineoplásicos Imunológicos/farmacologia , Complexo CD3/imunologia , Leucossialina/imunologia , Melanoma/terapia , Ácido N-Acetilneuramínico/química , Linfócitos T/imunologia , Animais , Apoptose , Proliferação de Células , Citotoxicidade Imunológica , Feminino , Humanos , Técnicas In Vitro , Melanoma/imunologia , Melanoma/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Sci Rep, v. 11, 19634, out. 2021
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-4049

RESUMO

The persistent increase of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) infections negatively impacts Tuberculosis treatment outcomes. Host-directed therapies (HDT) pose an complementing strategy, particularly since Mtb is highly successful in evading host-defense by manipulating host-signaling pathways. Here, we screened a library containing autophagy-modulating compounds for their ability to inhibit intracellular Mtb-bacteria. Several active compounds were identified, including two drugs of the diphenylbutylpiperidine-class, Fluspirilene and Pimozide, commonly used as antipsychotics. Both molecules inhibited intracellular Mtb in pro- as well as anti-inflammatory primary human macrophages in a host-directed manner and synergized with conventional anti-bacterials. Importantly, these inhibitory effects extended to MDR-Mtb strains and the unrelated intracellular pathogen, Salmonella enterica serovar Typhimurium (Stm). Mechanistically Fluspirilene and Pimozide were shown to regulate autophagy and alter the lysosomal response, partly correlating with increased bacterial localization to autophago(lyso)somes. Pimozide’s and Fluspirilene’s efficacy was inhibited by antioxidants, suggesting involvement of the oxidative-stress response in Mtb growth control. Furthermore, Fluspirilene and especially Pimozide counteracted Mtb-induced STAT5 phosphorylation, thereby reducing Mtb phagosome-localized CISH that promotes phagosomal acidification. In conclusion, two approved antipsychotic drugs, Pimozide and Fluspirilene, constitute highly promising and rapidly translatable candidates for HDT against Mtb and Stm and act by modulating the autophagic/lysosomal response by multiple mechanisms.

16.
Ned Tijdschr Geneeskd ; 1642020 06 17.
Artigo em Holandês | MEDLINE | ID: mdl-32749798

RESUMO

In recent years, more patients with psychiatric disorders are receiving physician-assisted death (PAD). In the Netherlands, since more than 25 years psychiatric suffering is seen as a legitimate reason for PAD, but an additional independent assessment is required. Scarce empirical research shows that patients who receive PAD on the basis of psychiatric suffering have long-standing and complex complaints. Among these patients, depression and personality disorders are relatively common. The ethical justification of PAD for patients with psychiatric disorders has been the subject of debate for decades. Decisions about competence and the irremediability of suffering are challenging and for many authors reason enough to reject PAD based on psychiatric suffering. Others regard the exclusion of all patients with mental disorders as unjust. Empirical research and ethical consideration are needed for better founded considerations and a more widely supported practice concerning patients with a mental disorder who request PAD.


Assuntos
Transtornos Mentais/psicologia , Psiquiatria/ética , Suicídio Assistido/ética , Adulto , Humanos , Princípios Morais , Países Baixos , Suicídio Assistido/psicologia
17.
J Geophys Res Atmos ; 125(8): e2019JD031433, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32714723

RESUMO

An analysis is presented of electric fields in thunderclouds using a recently proposed method based on measuring radio emission from extensive air shower events during thunderstorm conditions. This method can be regarded as a tomography of thunderclouds using cosmic rays as probes. The data cover the period from December 2011 till August 2014. We have developed an improved fitting procedure to be able to analyze the data. Our measurements show evidence for the main negative-charge layer near the -10° isotherm. This we have seen for a winter as well as for a summer cloud where multiple events pass through the same cloud and also the vertical component of the electric field could be reconstructed. On the day of measurement of some cosmic-ray events showing evidence for strong fields, no lightning activity was detected within 100 km distance. For the winter events, the top heights were between 5 and 6 km, while in the summer, typical top heights of 9 km were seen. Large horizontal components in excess of 70 kV/m of the electric fields are observed in the middle and top layers.

18.
Phys Rev Lett ; 124(10): 105101, 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32216418

RESUMO

We use the Low Frequency Array (LOFAR) to probe the dynamics of the stepping process of negatively charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of vhf (30-80 MHz) radiation are emitted in short-duration bursts (<10 µs). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain x-ray emission from lightning leaders, as x rays from laboratory leaders tend to be associated with corona flashes. Surprisingly, we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.

19.
Psychiatr Serv ; 71(6): 621-623, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32041511

RESUMO

Physician-assisted death is becoming legal in an increasing number of jurisdictions, but psychiatric patients are often explicitly excluded. However, in some countries, including the Netherlands, physician-assisted death of psychiatric patients is allowed. This Open Forum describes a patient with schizophrenia and symptoms diagnosed as refractory musical hallucinations. The patient requested assistance in dying only to recover after a mandatory second opinion, where his complaints were recognized as intrusive thoughts and treated accordingly. This case is used to reflect on how to deal with uncertainty about physician-assisted death of psychiatric patients and to argue for implementation of a due-diligence procedure, such as the one proposed in the Dutch Psychiatric Association's recent guideline concerning this issue.


Assuntos
Eutanásia Ativa Voluntária/psicologia , Esquizofrenia/terapia , Psicologia do Esquizofrênico , Suicídio Assistido/psicologia , Adulto , Eutanásia Ativa Voluntária/legislação & jurisprudência , Humanos , Masculino , Países Baixos , Encaminhamento e Consulta , Suicídio Assistido/legislação & jurisprudência
20.
EJNMMI Res ; 9(1): 82, 2019 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444658

RESUMO

RATIONALE: The use of 16α-[18F]fluoro-17ß-estradiol (FES) positron emission tomography (PET) in clinical dilemmas and for therapy decision-making in lesions expressing estrogen receptors is growing. However, on a considerable number of FES PET scans, previously performed in a research and clinical setting in our institution, FES uptake was noticed in the lungs without an oncologic substrate. We hypothesized that this uptake was related to pulmonary fibrosis as a result of radiation therapy. This descriptive study therefore aimed to investigate whether radiation therapy in the thoracic area is possibly related to enhanced pulmonary, non-tumor FES uptake. METHODS: All FES-PET/CT scans performed in our institution from 2008 to 2017 were retrospectively analyzed. Scans from patients who had received irradiation in the thoracic area prior to the scan were compared to scans of patients who had never received irradiation in the thoracic area. The primary outcome was the presence of enhanced non-tumor FES uptake in the lungs, defined as visually increased FES uptake in the absence of an oncologic substrate on the concordant (contrast-enhanced) CT scan. All CT scans were evaluated for the presence of fibrosis or oncologic substrates. RESULTS: A total of 108 scans were analyzed: 70 scans of patients with previous irradiation in the thoracic area and 38 of patients without. Enhanced non-tumor FES uptake in the lungs was observed in 39/70 irradiated patients (56%), versus in 9/38 (24%) of non-irradiated patients. Fibrosis was present in 37 of the 48 patients with enhanced non-tumor FES uptake (77%), versus in 15 out of 60 (25%) patients without enhanced non-tumor uptake, irrespective of radiotherapy (p < 0.001). CONCLUSION: After irradiation of the thorax, enhanced non-tumor uptake on FES-PET can be observed in the radiation field in a significant proportion of patients. This seems to be related to fibrosis. When observing enhanced FES uptake in the lungs, this should not be interpreted as metastases. Information on recent radiation therapy or history of pulmonary fibrosis should therefore be taken into consideration.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA