Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
2.
Tijdschr Psychiatr ; 63(4): 283-286, 2021.
Artigo em Holandês | MEDLINE | ID: mdl-33913144

RESUMO

BACKGROUND: In the last decade, regulations regarding the fitness to drive in The Netherlands have been changed extensively. AIM: To describe the changes in the regulations, and to evaluate the consequences for daily practice. METHOD: Overview of changes in the regulations concerning the fitness to drive as published in the Dutch legislation announcements in the past 10 years. RESULTS: Important changes have been implemented regarding the regulations on fitness to drive in patients with affective disorders, psychotic disorders, dementia, ADHD and pervasive developmental disorders. CONCLUSION: Compared to 2010, the regulations concerning the fitness to drive in psychiatric disorders are less rigid, more balanced, and more evidence based. Therefore, it has become easier to inform and advise the patient on this topic.


Assuntos
Condução de Veículo/legislação & jurisprudência , Condução de Veículo/psicologia , Transtornos Mentais/complicações , Acidentes de Trânsito/prevenção & controle , Guias como Assunto , Humanos , Competência Mental , Transtornos Mentais/psicologia , Países Baixos , População Branca
3.
Tijdschr Psychiatr ; 57(5): 361-6, 2015.
Artigo em Holandês | MEDLINE | ID: mdl-26028017

RESUMO

Takotsubo cardiomyopathy is an acute, stress-induced, reversible cardiac syndrome and can occur as a rare complication in electroconvulsive therapy. We give further details of this complication by referring to the case of a 67-year-old female patient. In addition, we give a brief description of the background of the syndrome. If this syndrome is suspected, the patient should immediately be referred for cardiac diagnostic tests to rule out myocardial infarction. There is no absolute contra-indication to ECT for a patient who has experienced Takotsubo cardiomyopathy. However, to start ECT treatment again it is recommended that this should be performed in a general hospital and in combination with beta-blockers.


Assuntos
Eletroconvulsoterapia/efeitos adversos , Cardiomiopatia de Takotsubo/etiologia , Idoso , Feminino , Humanos , Miocárdio Atordoado/etiologia
4.
Phys Rev Lett ; 110(11): 110501, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25166517

RESUMO

Dissipative engineering constitutes a framework within which quantum information processing protocols are powered by system-environment interaction rather than by unitary dynamics alone. This framework embraces noise as a resource and, consequently, offers a number of advantages compared to one based on unitary dynamics alone, e.g., that the protocols are typically independent of the initial state of the system. However, the time independent nature of this scheme makes it difficult to imagine precisely timed sequential operations, conditional measurements, or error correction. In this work, we provide a path around these challenges, by introducing basic dissipative gadgets which allow us to precisely initiate, trigger, and time dissipative operations while keeping the system Liouvillian time independent. These gadgets open up novel perspectives for thinking of timed dissipative quantum information processing. As an example, we sketch how measurement-based computation can be simulated in the dissipative setting.

5.
Phys Rev Lett ; 109(26): 267209, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23368615

RESUMO

We present a combined theoretical and experimental study of spin and charge dynamics on the homodinuclear compound [Ni2(II)(L-N4Me2)(emb)]. The theoretically calculated oscillator strengths of the ground-state absorption spectrum show an acceptable agreement with experiment. We predict a local ultrafast laser-induced spin-flip scenario, which involves charge-transfer states. Experimentally, we observe charge dynamics on two different time scales. The two relevant, transient electronic states and their electronic properties are also theoretically characterized. These results provide a joint investigation of the homodinuclear complex and suggest a realistic scenario for ultrafast spin dynamics and other optical-related manipulations.

6.
Tijdschr Psychiatr ; 52(8): 555-64, 2010.
Artigo em Holandês | MEDLINE | ID: mdl-20697995

RESUMO

BACKGROUND: A question that often arises in daily practice is whether a psychiatric patient should be considered as still fit to drive. AIM: To describe the Dutch regulations concerning psychiatric patients' fitness to drive and to evaluate the scientific basis of these regulations. METHOD: Information about the current regulations was collected and summarised and the specialist literature was reviewed. RESULTS: The regulations in the Netherlands are rather strict and as a result persons with a psychiatric illness can sometimes have their driving license withdrawn for a long period. The literature that was reviewed reveals that there is much uncertainty concerning the relationship between psychiatric illness and its effects on fitness to drive. CONCLUSION: The specialist literature indicates that some of the Dutch regulations are unfair and too rigid. In this article the consequences for daily practice are considered and a plea is made for more research and for laws and regulations that have a more solid basis.


Assuntos
Exame para Habilitação de Motoristas/legislação & jurisprudência , Condução de Veículo/legislação & jurisprudência , Condução de Veículo/psicologia , Transtornos Mentais/complicações , Acidentes de Trânsito/legislação & jurisprudência , Acidentes de Trânsito/prevenção & controle , Idoso , Exame para Habilitação de Motoristas/psicologia , Feminino , Humanos , Masculino , Transtornos Mentais/psicologia , Países Baixos , Testes Psicológicos , Fatores de Risco
7.
Phys Rev Lett ; 104(17): 170405, 2010 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20482096

RESUMO

In this Letter we show that the field of operator space theory provides a general and powerful mathematical framework for arbitrary Bell inequalities, in particular, regarding the scaling of their violation within quantum mechanics. We illustrate the power of this connection by showing that bipartite quantum states with local, Hilbert space dimension n can violate a Bell inequality by a factor of order sqrt[n]/(log{2}n) when observables with n possible outcomes are used. Applications to resistance to noise, Hilbert space dimension estimates, and communication complexity are given.

8.
Leukemia ; 23(2): 305-12, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18987661

RESUMO

Fludarabine exposure leads to impaired peripheral blood stem cell (PBSC) mobilization in indolent lymphoproliferative disorders (LPD). We previously reported that only 34% of fludarabine-exposed patients mobilized successfully using granulocyte-colony stimulating factor (G-CSF; median 10 microg/kg/day) with or without chemotherapy, with unpredictable kinetics and moderate infectious morbidity. Stem cell factor (SCF) plus high-dose twice daily (b.d.) G-CSF may improve mobilization in these patients. SCF 20 microg/kg/day subcutaneously was given from day 1, G-CSF 12 microg/kg b.d. subcutaneously from day 4, apheresis commenced from day 6. Previous study patients served as historical controls. Thirty five patients with indolent LPD were enrolled, median age was 54 years (range 31-66), 66% male, median cumulative prior fludarabine dose was 660 (405-900) mg. Overall, 22 patients (63%) collected >or= 2.0 x 10(6)/kg PBSC (success), compared to 34% controls (odds ratio (OR) 3.2; 95% confidence interval (CI) (1.2, 9.3); P=0.021). Median CD34(+) yield overall was 2.3 x 10(6)/kg (0.53-8.97) from median four (2-6) aphereses. Study patients >or= 50 years mobilized successfully more frequently than controls (58 versus 17%; P=0.0065). Adjusting for age, successful mobilization remained significantly higher in the current study (OR 4.2; 95% CI (1.4, 14.0); P=0.008). SCF/high-dose b.d. G-CSF improves PBSC mobilization efficacy after fludarabine exposure, over mobilization using G-CSF as the mobilizing cytokine. This combined growth factor strategy is a preferred mobilization method for fludarabine-exposed patients.


Assuntos
Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Mobilização de Células-Tronco Hematopoéticas/métodos , Transtornos Linfoproliferativos/tratamento farmacológico , Fator de Células-Tronco/administração & dosagem , Vidarabina/análogos & derivados , Adulto , Idoso , Contagem de Células , Feminino , Filgrastim , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes , Resultado do Tratamento , Vidarabina/uso terapêutico
9.
Phys Rev Lett ; 101(15): 150402, 2008 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-18999575

RESUMO

We investigate what a snapshot of a quantum evolution--a quantum channel reflecting open system dynamics--reveals about the underlying continuous time evolution. Remarkably, from such a snapshot, and without imposing additional assumptions, it can be decided whether or not a channel is consistent with a time (in)dependent Markovian evolution, for which we provide computable necessary and sufficient criteria. Based on these, a computable measure of "Markovianity" is introduced. We discuss how the consistency with Markovian dynamics can be checked in quantum process tomography. The results also clarify the geometry of the set of quantum channels with respect to being solutions of time (in)dependent master equations.

10.
Phys Rev Lett ; 100(16): 167202, 2008 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-18518239

RESUMO

We show that the existence of string order in a given quantum state is intimately related to the presence of a local symmetry by proving that both concepts are equivalent within the framework of finitely correlated states. Once this connection is established, we provide a complete characterization of local symmetries in these states. The results allow us to understand in a straightforward way many of the properties of string order parameters, like their robustness or fragility under perturbations and their typical disappearance beyond strictly one-dimensional lattices. We propose and discuss an alternative definition, ideally suited for detecting phase transitions, and generalizations to two and more spatial dimensions.

11.
Ned Tijdschr Geneeskd ; 150(39): 2155-8, 2006 Sep 30.
Artigo em Holandês | MEDLINE | ID: mdl-17059091

RESUMO

An 83-year-old woman presented at the neurology out-patient clinic with acute bilateral weakness of the calf muscles that had lasted for a few weeks. Ultrasound and MRI evaluation of the Achilles tendons revealed bilateral ruptures. Possible predisposing factors included treatment with prednisone pulse therapy for obstructive pulmonary disease and prior polymyalgia rheumatica. Surgical reconstruction of the tendons resulted in a major clinical improvement. Rupture of the Achilles tendons can occur spontaneously, and sometimes bilaterally. A predisposing factor is present in nearly every case of spontaneous bilateral rupture of the Achilles tendons. As in spontaneous unilateral ruptures, the most frequently described predisposing factor is the use of corticosteroids or quinolones.


Assuntos
Tendão do Calcâneo/lesões , Glucocorticoides/efeitos adversos , Prednisona/efeitos adversos , Tendão do Calcâneo/cirurgia , Idoso de 80 Anos ou mais , Feminino , Glucocorticoides/uso terapêutico , Humanos , Polimialgia Reumática/tratamento farmacológico , Prednisona/uso terapêutico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Ruptura Espontânea , Resultado do Tratamento
12.
Phys Rev Lett ; 96(22): 220601, 2006 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-16803296

RESUMO

The projected entangled pair state (PEPS) representation of quantum states on two-dimensional lattices induces an entanglement based hierarchy in state space. We show that the lowest levels of this hierarchy exhibit a very rich structure including states with critical and topological properties. We prove, in particular, that coherent versions of thermal states of any local 2D classical spin model correspond to such PEPS, which are in turn ground states of local 2D quantum Hamiltonians. This correspondence maps thermal onto quantum fluctuations, and it allows us to analytically construct critical quantum models exhibiting a strict area law scaling of the entanglement entropy in the face of power law decaying correlations. Moreover, it enables us to show that there exist PEPS which can serve as computational resources for the solution of NP-hard problems.

13.
Phys Rev Lett ; 95(7): 070501, 2005 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-16196769

RESUMO

We consider the optimal cloning of quantum coherent states with single-clone and joint fidelity as figures of merit. While the latter is maximized by a Gaussian cloner, the former is not: the optimal single-clone fidelity for a symmetric 1-to-2 cloner is 0.6826, compared to 2/3 in a Gaussian setting. This cloner can be realized with an optical parametric amplifier and certain non-Gaussian bimodal states. Finally, we show that the single-clone fidelity of the optimal 1-to-infinity cloner is 1/2. It is achieved by a Gaussian scheme and cannot be surpassed even with supplemental bound entangled states.

14.
Phys Rev Lett ; 95(11): 110503, 2005 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-16196992

RESUMO

We consider the deterministic generation of entangled multiqubit states by the sequential coupling of an ancillary system to initially uncorrelated qubits. We characterize all achievable states in terms of classes of matrix-product states and give a recipe for the generation on demand of any multiqubit state. The proposed methods are suitable for any sequential generation scheme, though we focus on streams of single-photon time-bin qubits emitted by an atom coupled to an optical cavity. We show, in particular, how to generate familiar quantum information states such as W, Greenberger-Horne-Zeilinger, and cluster states within such a framework.

15.
Leuk Lymphoma ; 46(11): 1575-9, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16236612

RESUMO

High-dose therapy (HDT) for non-Hodgkins lymphoma (NHL) and multiple myeloma (MM) is considered a feasible option for patients aged 60 years. This study compared the outcomes for all patients aged 60 years treated with HDT at the center to a matched cohort group aged <60 years. Results for patients who were 60 years at HDT between 1997--2002 were retrospectively analysed to assess efficacy and safety. Event-free (EFS) and overall survival (OS) rates were compared with a cohort group, matched by disease type, chemotherapy sensitivity, year of treatment and conditioning regimen. Patients with NHL were also matched by International Prognostic Index score. Forty patients aged 60 years were identified. Median age was 65 (range 60--76) with 22 MM and 18 NHL; 50% had 1 or more co-morbidity; 35% had cardiovascular co-morbidity vs. 18% of controls (p=0.075). Response rates (RR) following HDT for MM were: 4 (18%) complete responses (CR) and 18 (82%) partial responses (PR), giving an overall response rate (ORR) of 100%, vs. 77% for controls (p=0.02). For NHL patients there were: 8 CR (44%) and 4 PR (22%), giving an ORR of 67%, vs. 83% for controls (p=0.3). Transplant-related mortality was 8% compared to 5% in controls (p=0.6). Toxicities were similar with the exception of cardiac toxicity, which was significantly higher in patients aged 60 years vs. controls (50% grade 3 vs. 10%: p<0.0001). Atrial fibrillation was the most frequent cardiovascular toxicity (9 patients). At a median follow-up of 33 months, there is no significant difference between older vs. younger patients in median EFS (24 vs. 38 months: p=0.78) or OS (40 months vs. not reached: p=0.23). HDT is feasible and effective in selected patients 60 years with MM and NHL. Patients 60 years are more susceptible to cardiovascular toxicities, particularly atrial fibrillation, but have similar or better response rates following HDT and similar long-term outcomes to younger patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Doenças Cardiovasculares/induzido quimicamente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Linfoma não Hodgkin/complicações , Mieloma Múltiplo/complicações , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Adulto , Fatores Etários , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/mortalidade , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/mortalidade , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Transplante Autólogo
16.
Phys Rev Lett ; 94(14): 140601, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15904055

RESUMO

We construct a general renormalization-group transformation on quantum states, independent of any Hamiltonian dynamics of the system. We illustrate this procedure for translational invariant matrix product states in one dimension and show that product, Greenberger-Horne-Zeilinger, W, and domain wall states are special cases of an emerging classification of the fixed points of this coarse-graining transformation.

17.
Phys Rev Lett ; 94(15): 150503, 2005 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-15904127

RESUMO

We consider the storage and transmission of a Gaussian distributed set of coherent states of continuous variable systems. We prove a limit on the average fidelity achievable when the states are transmitted or stored by a classical channel, i.e., a measure and repreparation scheme which sends or stores classical information only. The obtained bound is tight and serves as a benchmark which has to be surpassed by quantum channels in order to outperform any classical strategy. The success in experimental demonstrations of quantum memories as well as quantum teleportation has to be judged on this footing.

18.
Phys Rev Lett ; 92(8): 087903, 2004 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-14995817

RESUMO

We investigate the entanglement properties of multimode Gaussian states, which have some symmetry with respect to the ordering of the modes. We show how the symmetry constrains the entanglement between two modes of the system. In particular, we determine the maximal entanglement of formation that can be achieved in symmetric graphs like chains, 2D and 3D lattices, mean field models and the platonic solids. The maximal entanglement is always attained for the ground state of a particular quadratic Hamiltonian. The latter thus yields the maximal entanglement among all quadratic Hamiltonians having the considered symmetry.

20.
Phys Rev Lett ; 91(10): 107901, 2003 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-14525506

RESUMO

We show that for a fixed amount of entanglement, two-mode squeezed states are those that maximize Einstein-Podolsky-Rosen-like correlations. We use this fact to determine the entanglement of formation for all symmetric Gaussian states corresponding to two modes. This is the first instance in which this measure has been determined for genuine continuous variable systems.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...