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1.
Eur Rev Med Pharmacol Sci ; 26(4): 1382-1387, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35253194

RESUMO

OBJECTIVE: The first wave of coronavirus pandemic and concomitant restrictive measures affected sleep. We slept more than usual, but the quality was worse. As the pandemic continues, a second period of restrictive measures was initiated, and no data exist about their impact on sleep. The aim of this study was to compare quantity and quality of sleep between the two periods of restrictive measures, due to the Coronavirus Disease-19 (COVID-19) pandemic in Greece. MATERIALS AND METHODS: A web-based survey using a short 13-item questionnaire was created and was distributed online. This included information about demographic and professional data, quantitative and qualitative characteristics of sleep, degree of abidance in lockdown measures, and data about COVID-19 infection or close contact with active confirmed cases. RESULTS: A total of 1,078 questionnaires were evaluated (first period, n=963; second period, n=115). Sleep duration was shorter during the second lockdown (mean difference -0.51h; 95% confidence interval, (CI), -0.82, -0.19, p=0.002). Compared to usual habits, sleep increased in first wave (mean difference +0.37h; 95% CI, 0.26, 0.47; p<0.001) and decreased in second wave (mean difference -0.35h; 95% CI, -0.60, -0.09; p=0.009). Regarding quality of sleep, less participants reported good quality of sleep during the second wave compared to the first (p=0.006). Finally, compliance to restriction measures was lower and the prevalence of confirmed illness or close contact with COVID-19 cases among participants was higher during the second period than during the first one (p<0.001 and p=0.028, respectively). CONCLUSIONS: Our data showed that sleep duration increased during the first lockdown and decreased in the second one, when compared to usual habits. Moreover, sleep quality progressively deteriorated, as the restrictive measures due to coronavirus pandemic continued.


Assuntos
COVID-19 , Quarentena , Qualidade do Sono , Adulto , Feminino , Grécia , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
2.
Ann R Coll Surg Engl ; 102(4): 300-307, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31928359

RESUMO

INTRODUCTION: Parietal cell/oncocytic gastric carcinomas are very rare and various aspects of this group remain unclear. The human epithelial growth factor receptor 2 (HER2) status of these tumours is largely unknown. METHODS: We performed a systematic electronic search of the literature and clinicopathological presentation of two cases including first-time complete assessment of HER2 status. Thirty-two patients with a mean age of 64.3 years, 87.5% of whom were male, were included in this review. FINDINGS: Half of the cases were recorded in Asia. Median follow-up was 24 months. There was no predominant site of development, while underlying histological abnormalities were present in 25%. At initial presentation, lymph node involvement was evident in 46.6% while distant metastatic disease was present in 9.3%. Presentation at stage I occurred in 55.6%. Potentially curative surgical/interventional treatment was intended in 90.6%. Recurrence occurred in 6.6%, while death was recorded in 19.2%, with cancer-related deaths reaching 11.5%. The one- and three-year survival rates were 84.2% and 79%, respectively. Our two cases displayed negative HER2 expression. CONCLUSIONS: This systematic review demonstrates that this group of malignancies is very rare but possibly underdiagnosed. The disease commonly presents at early stage, mainly affecting middle-aged men. The prognosis is generally favourable even in cases of advanced disease. The HER2 expression and its correlation with the outcomes need to be further explored.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma/diagnóstico , Recidiva Local de Neoplasia/epidemiologia , Células Parietais Gástricas/patologia , Receptor ErbB-2/análise , Neoplasias Gástricas/diagnóstico , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Carcinoma/mortalidade , Carcinoma/patologia , Carcinoma/terapia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Gastrectomia , Grécia , Humanos , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Receptor ErbB-2/metabolismo , Fatores Sexuais , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Taxa de Sobrevida
3.
Postgrad Med ; 131(7): 501-508, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31483196

RESUMO

Objectives: Aiginition Longitudinal Biomarker Investigation Of Neurodegeneration (ALBION) is a longitudinal ongoing study initiated in 2018 that takes place in the Cognitive Disorders Clinic of Aiginition Hospital of the National and Kapodistrian University of Athens. Its aim is to address several research questions concerning the preclinical and prodromal stage of Alzheimer's disease and explore potential markers for early detection, prediction, and primary prevention of dementia. Methods: We here present the design and the preliminary baseline characteristics of ALBION. The sample of our study consists of people aged over 50 who are concerned about their memory but are cognitively normal (CN) or have mild cognitive deficits. Each participant undergoes an extensive assessment including several demographic, medical, social, environmental, clinical, nutritional, neuropsychological determinants and lifestyle activities. Furthermore, we are collecting data from portable devices, neuroimaging techniques and biological samples (blood, stools, CSF). All participants are assessed annually for a period of 10 years. Results: In total, 47 participants have completed the initial evaluation up to date and are divided in two groups, CN individuals (N = 26) and MCI patients (N = 21), based on their cognitive status. The participants are, on average, 64 years old, 46.3% of the sample is male with an average of 12.73 years of education. MCI patients report more comorbidities and have a lower score in the MMSE test. Regarding APOE status, 2 participants are ε4 homozygotes and 10 ε4 heterozygotes. CSF analyses (Aß42, Τ-tau, P-tau) revealed no differences between the two groups. Conclusion: The ALBION study offers an opportunity to explore preclinical dementia and identify new and tailored markers, particularly relating to lifestyle. Further investigation of these populations may provide a wider profile of the changes taking place in the preclinical phase of dementia, leading to potentially effective therapeutic and preventive strategies.


Assuntos
Doença de Alzheimer/prevenção & controle , Disfunção Cognitiva/metabolismo , Prevenção Primária , Sintomas Prodrômicos , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Apolipoproteínas E/genética , Biomarcadores , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , Diagnóstico Precoce , Eletroencefalografia , Feminino , Neuroimagem Funcional , Grécia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/líquido cefalorraquidiano , Dados Preliminares , Proteínas tau/líquido cefalorraquidiano
4.
Psychiatriki ; 27(3): 222-226, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27837576

RESUMO

Α case of a chronic idiopathic form of a severe type of Restless Legs Syndrome (RLS), which developed during pregnancy and persisted after this, misdiagnosed for 34 years as radiculopathy S1, is reported. In spite of the thorough clinical and laboratory investigation, in addition to constant changes of the therapeutic approach, the diagnosis of S1 radiculopathy could not be confirmed, resulting in a chronic clinical course; the latter was characterized by relapses and remissions not attributed or linked in any way to the treatment (various types of). In fact, it was due to a routine workup in a sleep clinic, where the patient was referred because of a coincident chronic insomnia (Restless Legs Syndrome is a known and important cause of insomnia/chronic insomnia), which resulted in a proper diagnosis and treatment of this case. With the use of Restless Legs Syndrome appropriate treatment (Pramipexole 0.18 mg taken at bedtime, a dopaminergic agent and Level A recommended drug for Restless Legs Syndrome) an excellent response and immediate elimination of symptoms was achieved. Restless Legs Syndrome may present with a variety of symptoms (with the most prominent shortly being reported with the acronym URGE: Urge to move the legs usually associated with unpleasant leg sensations, Rest induces symptoms, Getting active brings relief, Evening and night deteriorate symptoms); given the fact that Restless Legs Syndrome presents with a great variety and heterogeneity of symptoms (mostly pain, dysesthesia and paresthesia), which may occur in several other diseases (the so called "RLS mimics"), proper diagnosis of Restless Legs Syndrome usually fails. Restless Legs Syndrome misinterpreted as S1 radiculopathy, to the best of our knowledge, has not been reported yet in the literature. Here, case history, clinical course and common RLS mimics are presented. Different forms of Restless Legs Syndrome manifestations, which are commonly -as in this case- misinterpreted due to their mimicking several pathological conditions, Restless Legs Syndrome prevalence on general population according to various large epidemiological studies and pathogenic hypotheses on the issue of Restless Legs Syndrome are discussed. Finally, by presenting another possible "RLS-mimic" our aim is to highlight the common misdiagnosis of Restless Legs Syndrome, which can mimic a variety of disorders, some of which are very common, such as an S1 radiculopathy, thus raising concern among doctors of various specialties addressed to by Restless Legs Syndrome sufferers, on the importance of proper diagnosis of the syndrome.


Assuntos
Erros de Diagnóstico , Complicações na Gravidez/diagnóstico , Transtornos Puerperais/diagnóstico , Radiculopatia/diagnóstico , Síndrome das Pernas Inquietas/diagnóstico , Sacro , Adulto , Benzotiazóis/uso terapêutico , Feminino , Grécia , Humanos , Pramipexol , Gravidez , Complicações na Gravidez/tratamento farmacológico , Transtornos Puerperais/tratamento farmacológico , Síndrome das Pernas Inquietas/tratamento farmacológico
5.
Case Rep Gastroenterol ; 7(3): 409-13, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24163654

RESUMO

We present a rare case of toxic megacolon accompanied by necrosis of the colon due to chronic dilation caused by stenosis of the sigmoid colon as a complication of diverticulitis. The patient presented at the emergency department with diffuse abdominal pain, fever (38.8°C) and tachycardia (120 beats/min). Physical examination revealed distension and tenderness on deep palpation on the left lower quadrant without peritoneal signs. Abdominal computed tomography showed located stenosis in the sigmoid colon and marked dilation of the descending (12 cm diameter) and transverse (7.5 cm diameter) colon. A few hours later, the patient developed severe septic shock with electrolyte abnormalities. He had a history of two prior admissions to our hospital due to crises of acute diverticulitis. Based on Jalan's criteria the diagnosis was compatible with toxic megacolon. The patient's condition deteriorated suddenly and an emergency colectomy was performed. The operative findings revealed a necrotic colon. Histology examination confirmed the diagnosis of ischemia of the colon. To our knowledge this is the first published report in the literature which refers to a rare complication of diverticulitis, namely chronic stenosis which complicated to colonic ischemia and toxic megacolon.

6.
J Neurosci Methods ; 185(1): 133-42, 2009 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-19747507

RESUMO

The time-varying microstructure of sleep EEG spindles may have clinical significance in dementia studies and can be quantified with a number of techniques. In this paper, real and simulated sleep spindles were regarded as AM/FM signals modeled by six parameters that define the instantaneous envelope (IE) and instantaneous frequency (IF) waveforms for a sleep spindle. These parameters were estimated using four different methods, namely the Hilbert transform (HT), complex demodulation (CD), matching pursuit (MP) and wavelet transform (WT). The average error in estimating these parameters was lowest for HT, higher but still less than 10% for CD and MP, and highest (greater than 10%) for WT. The signal distortion induced by the use of a given method was greatest in the case of HT and MP. These two techniques would necessitate the removal of about 0.4s from the spindle data, which is an important limitation for the case of spindles with duration less than 1s. Although the CD method may lead to a higher error than HT and MP, it requires a removal of only about 0.23s of data. An application of this sleep spindle parameterization via the CD method is proposed, in search of efficient EEG-based biomarkers in dementia. Preliminary results indicate that the proposed parameterization may be promising, since it can quantify specific differences in IE and IF characteristics between sleep spindles from dementia subjects and those from aged controls.


Assuntos
Demência/diagnóstico , Demência/fisiopatologia , Eletroencefalografia/métodos , Transtornos do Sono-Vigília/diagnóstico , Transtornos do Sono-Vigília/fisiopatologia , Sono/fisiologia , Idoso , Algoritmos , Biomarcadores/análise , Córtex Cerebral/fisiopatologia , Demência/complicações , Potenciais Evocados/fisiologia , Análise de Fourier , Humanos , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador , Transtornos do Sono-Vigília/etiologia , Fatores de Tempo
8.
Eur Respir J ; 34(3): 687-93, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19357151

RESUMO

Some patients with obstructive sleep apnoea syndrome (OSAS; respiratory distress index (RDI) of >5 events.h(-1)) experience residual excessive daytime subjective sleepiness (Epworth Sleepiness Scale (ESS) score of >10), despite adequate use of continuous positive airway pressure (CPAP) therapy. The aim of the present study was to identify clinical and polysomnographic predictors of this sleepiness. Clinical and polysomnographic variables and ESS score were evaluated in 208 OSAS patients with an ESS score of >10 before (initial assessment) and after > or =6 months of adequate (> or =4 h.day(-1)) CPAP use. Following CPAP treatment, 114 (55%) patients showed an abnormal ESS score (>10; CPAP nonresponders), whereas 94 (45%) showed a normal ESS score (<11; CPAP responders). Of the CPAP responders, none had a history of depression, whereas the converse was true for 38.8% of CPAP nonresponders. In addition, multivariate logistic regression analysis revealed that the independent predictors of residual excessive daytime sleepiness following CPAP therapy were a history of diabetes and heart disease, and a higher ESS score and lower RDI on initial assessment. In conclusion, predictors of residual excessive sleepiness in adequately CPAP-treated OSAS were a history of depression, diabetes and heart disease, and a higher ESS score and lower RDI on initial assessment.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Distúrbios do Sono por Sonolência Excessiva/etiologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Distúrbios do Sono por Sonolência Excessiva/diagnóstico , Distúrbios do Sono por Sonolência Excessiva/fisiopatologia , Feminino , Seguimentos , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Fatores de Risco , Apneia Obstrutiva do Sono/diagnóstico , Falha de Tratamento , Adulto Jovem
9.
J Neurol ; 254(12): 1642-8, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18008026

RESUMO

BACKGROUND: Epidemiological studies on the distribution of multiple sclerosis (MS) conducted in the Mediterranean area in the last two decades have disclosed a significant increase in frequency of the disease, indicating caution when a latitude-related model of MS is accepted. Previous descriptive surveys in the province of Ferrara, northern Italy, carried out by our own epidemiological research group, have established that this area is at high risk for MS. OBJECTIVE: To confirm the above assumption and to update MS frequency estimates in this area. DESIGN AND SETTING: We conducted a community-based intensive prevalence and incidence study, by adopting a complete enumeration approach. RESULTS: On December 31, 2004, 423 patients (300 women and 123 men) suffering from definite or probable MS (Poser's criteria) living in the province of Ferrara, yielded a crude prevalence rate of 120.93 (95 % CI, 110.05-134.23) per 100,000, 164.26 for women and 73.59 for men. The average incidence from 1990 to 2003 was 4.35 per 100,000 (95 % CI, 3.77-4.99), 5.91 for women and 2.63 for men. The incidence rate,which was relatively stable during the previous 25 years (1965-1989) with a mean rate of 2.3 per 100,000, increased to a value of 3.39 per 100,000 in the period 1990-1994, 4.09 per 100,000 in the period 1995-1999 and 3.84 per 100,000 in the period 2000-2003. CONCLUSIONS: These results confirm that in Ferrara MS occurs more frequently than suggested by the geographic- related distribution model and, based on other recent national surveys, support the view that northern Italy is a high-risk area for the disease. The marked increase in MS prevalence rate, in comparison with previous investigations, is in part due to the increasing survival of patients as a result of improved supportive care and the accumulation of new incidence cases owing to the reduction in diagnostic latency for better quality of neurological diagnostic procedures. The incidence in the province of Ferrara was found to slowly change with an incremental trend,which cannot only be attributed to improvements in diagnostic ability. Environmental risk factors in genetically predisposed people over time could be considered.


Assuntos
Estudos Epidemiológicos , Esclerose Múltipla/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos
10.
Reumatismo ; 58(2): 157-64, 2006.
Artigo em Italiano | MEDLINE | ID: mdl-16829994

RESUMO

Most Byzantine medical texts described the rheumatic diseases. The Byzantine physicians, based on the ancient Greek texts, explained the causes of rheumatic diseases, described their symptoms and proposed certain treatments. The Byzantine medical sources described various types of rheumatic diseases, as inflammatory arthritis, chronic deformans polyarthritis, and gout. As it can be concluded by the available medical sources, during the Byzantine period rheumatic diseases constituted a serious medical and social problem, representing a remarkable cause of disability, and this complaint was part of the epidemiological interest of the Byzantine physicians.


Assuntos
Doenças Reumáticas/história , Artrite Gotosa/história , Artrite Gotosa/terapia , Bizâncio , História do Século XV , História Medieval , Humanos , Doenças Reumáticas/terapia
11.
J Hist Neurosci ; 14(4): 346-52, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16338692

RESUMO

The aim of this study is to present epilepsy according to the most famous and representative Byzantine physicians throughout the whole period of the Byzantine empire. Mainly Byzantine medical texts were used as sources. The Byzantine physicians considered epilepsy to be a serious medical problem and followed the Hippocratic tradition as far as the etiology of this disease is concerned. Their pathophysiological theories of epilepsy identified the brain as the site of the problem, but, based on the Hippocratic humoral theory, emphasized causes such as an excess of humors or insufficient circulation of phlegm in the brain. It is surprising to note the accuracy of the details they provide regarding the clinical description of the disease, especially the seizures; many of these are still accepted today. It is also surprising that there was a concurrent opinion during all this medieval period that epilepsy was strictly an organic disease of the brain and the demonic origin of it a prejudice of uneducated people.


Assuntos
Epilepsia/história , Medicina Arábica/história , Bizâncio , Epilepsia/fisiopatologia , História Antiga , História Medieval , Humanos
12.
Acta Otorhinolaryngol Ital ; 24(3): 165-70, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15584589

RESUMO

The present report refers to two patients presenting with grinding of the teeth (bruxism). A brief review is made of the literature concerning the aetiology of the disease, the clinical manifestations and diagnosis, as well as the therapeutic approach.


Assuntos
Bruxismo/complicações , Adulto , Feminino , Humanos , Hipertrofia/etiologia , Hipertrofia/patologia , Hipertrofia/cirurgia , Masculino , Músculo Masseter/patologia , Músculo Temporal/patologia
13.
Neurology ; 63(6): 1065-9, 2004 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-15452299

RESUMO

OBJECTIVE: To perform a large and detailed epidemiologic study on restless legs syndrome (RLS) during pregnancy and the puerperium. METHODS: A structured clinical interview, assessing symptoms since the beginning of pregnancy, was performed to a population of 642 pregnant women at the time of delivery and at follow-up evaluation (1, 3, and 6 months after delivery). Main hematologic tests were also evaluated. A woman was considered affected if she met the International RLS Study Group criteria for RLS diagnosis. RESULTS: Twenty-six percent of women were affected by RLS during their pregnancy. The disease was strongly related to the third trimester of pregnancy and tended to disappear reaching the time of delivery. Affected women presented lower values of hemoglobin and mean corpuscular volume compared with healthy subjects (both groups received the same supplemental iron and folate therapy). CONCLUSIONS: Pregnancy is associated with transient restless legs syndrome.


Assuntos
Complicações na Gravidez/epidemiologia , Transtornos Puerperais/epidemiologia , Síndrome das Pernas Inquietas/epidemiologia , Adulto , Suscetibilidade a Doenças , Índices de Eritrócitos , Feminino , Seguimentos , Hormônios Esteroides Gonadais/sangue , Hemoglobinas/análise , Humanos , Ferro/sangue , Itália/epidemiologia , Modelos Biológicos , Síndrome da Mioclonia Noturna/epidemiologia , Paridade , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/etiologia , Terceiro Trimestre da Gravidez , Prevalência , Transtornos Puerperais/sangue , Transtornos Puerperais/etiologia , Recidiva , Síndrome das Pernas Inquietas/sangue , Síndrome das Pernas Inquietas/etiologia , Síndrome das Pernas Inquietas/genética , Fatores de Risco , Transtornos Intrínsecos do Sono/epidemiologia , Distúrbios do Início e da Manutenção do Sono/epidemiologia
14.
J Chir (Paris) ; 131(8-9): 363-70, 1994.
Artigo em Francês | MEDLINE | ID: mdl-7844196

RESUMO

During the last 20 years (1972-1992), 421 patients underwent surgery for hydatid disease of the liver. 96 out of 421 patients had a rupture such as, intrabiliary rupture 49 patients, intrathoracic rupture 43 patients and free rupture in the peritoneal cavity 4 patients. The surgical treatment required a variety of procedures: 1) Prolonged tube drainage of the residual cavity and exploration of the common bile duct followed by either T tube drainage or sphincteroplasty or choledocho-duedonostomy if it was necessary, for intrabiliary rupture. 2) Lung resection if it was necessary, and evacuation plus drainage and the hepatic cavity followed by suture of the diaphragmatic rupture of closure of the bronchial opening if present for intrathoracic rupture. 3) Lavage and prolonged tube drainage of the hepatic cavity for free rupture in the peritoneal cavity. Five patients died in the postoperative period one from suppurative cholagitis, one from pulmonary embolism and 3 from M.O.F.


Assuntos
Doenças Biliares/etiologia , Equinococose Hepática/complicações , Doenças Peritoneais/etiologia , Doenças Torácicas/etiologia , Adolescente , Adulto , Idoso , Doenças Biliares/diagnóstico por imagem , Doenças Biliares/cirurgia , Drenagem , Equinococose Hepática/diagnóstico por imagem , Equinococose Hepática/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Peritoneais/cirurgia , Complicações Pós-Operatórias , Radiografia , Ruptura Espontânea , Doenças Torácicas/diagnóstico por imagem , Doenças Torácicas/cirurgia
15.
Ann Ophthalmol ; 13(10): 1167-8, 1981 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7316340

RESUMO

A rare case of fibroma of the inner and lower orbital wall in a 75-year-old man is described. The tumor was adherent to the periosteum of the orbital bones and occurred 1 1/2 years after an uncomplicated dacryocystectomy.


Assuntos
Dacriocistite/cirurgia , Fibroma/patologia , Neoplasias Orbitárias/patologia , Idoso , Fibroma/etiologia , Humanos , Masculino , Neoplasias Orbitárias/etiologia
17.
Opt Lett ; 3(5): 172-4, 1978 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19684736

RESUMO

Magnetic-field quantum beats are observed in Doppler-free two-photon free-induction decay. The 3S-4D transition in atomic sodium vapor is studied with fields up to 300 G. A strong dependence on the polarization of the excitation pulses is observed.

18.
Opt Lett ; 3(6): 209-11, 1978 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19684749

RESUMO

We have observed the effects of magnetic fields on four-wave mixing processes in atomic vapors. We have studied coherent vacuum-ultraviolet generation in Sr vapor via the process omega(1) + omega(2) + omega(3) ? omega(4) in fields of up to 50 kG. Magnetic tuning of the resonances of the third-order nonlinear susceptibility X((3)) was used to modify the dependence of the sum-frequency output power on the generated wavelength.

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