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2.
Prensa méd. argent ; 105(11): 810-815, dic2019. tab
Artigo em Inglês | LILACS, BINACIS | ID: biblio-1049824

RESUMO

Introduction: Pediculosis Capitis (head lice infestation) is the most common disease of the bloodsucking insect which affects approximately six to twenty million cases and results considerable economic burden annually. In this study we aim to investigate some medieval Persian views on the role of non-pharmacological treatment strategies for prevention and control of pediculosis and compare their prescriptions with current findings. Materials and methods: In this qualitative study, we reviewed some well-known Persian medicine (PM) textbooks based on the selected keywords (Shepesh, Reshk, Ghamal and Seyban) to collect the viewpoint of PM scholars for pediculosis and its treatments. Also, we searched in the databases such as PubMed, Science direct and Scopus about the topic. Results: Persian medicine scientists believed that there are six essential health principles (SetteZaroorieh), which can affect human health and prevent diseases including air, nutrition, exercise, sleep and wakefulness, exertion of unnecessary materials from the body and finally psychological concepts. Proper management of these essential factors can improve lifestyle of people affected with pediculosis and also play a key role in prevention of head lice infestation. Conclusion: There are several suitable recommendations for prevention and control of pediculosis according to essential health principles in PM which can consider beside current drug treatments and the individual health recommendations for complete control of the disease


Assuntos
Humanos , História Medieval , Infestações por Piolhos/terapia , Pediculus/efeitos dos fármacos , Terapias Complementares , Análise Qualitativa/história , Medicina Tradicional
3.
J Am Dent Assoc ; 150(12): 991, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31761024
4.
Nat Commun ; 10(1): 4264, 2019 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-31537802

RESUMO

Graded index (GRIN) lenses are commonly used for compact imaging systems. It is not widely appreciated that the ion-exchange process that creates the rotationally symmetric GRIN lens index profile also causes a symmetric birefringence variation. This property is usually considered a nuisance, such that manufacturing processes are optimized to keep it to a minimum. Here, rather than avoiding this birefringence, we understand and harness it by using GRIN lenses in cascade with other optical components to enable extra functionality in commonplace GRIN lens systems. We show how birefringence in the GRIN cascades can generate vector vortex beams and foci, and how it can be used advantageously to improve axial resolution. Through using the birefringence for analysis, we show that the GRIN cascades form the basis of a new single-shot Müller matrix polarimeter with potential for endoscopic label-free cancer diagnostics. The versatility of these cascades opens up new technological directions.


Assuntos
Endoscopia/instrumentação , Lentes , Neoplasias/diagnóstico por imagem , Óptica e Fotônica , Polarimetria de Varredura a Laser/instrumentação , Birrefringência , Neoplasias/diagnóstico , Refratometria , Polarimetria de Varredura a Laser/métodos
6.
Stud Health Technol Inform ; 266: 37-43, 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31397299

RESUMO

Genomic science has the potential to rapidly advance understanding of human biology in the medical context and the subsequent provision of tailored healthcare. Implementing such a disruptive and transformative technology into an existing and stretched health system will require a whole of system approach and a keen understanding of the limitations to be navigated in broadening the system to include genomic healthcare. This paper reports on the barriers to implementation faced by clinical demonstration projects in integrating into the existing infrastructure in Queensland.


Assuntos
Assistência à Saúde , Lentes , Genômica , Humanos , Gestão da Informação , Queensland
7.
Br Dent J ; 227(3): 198, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31399675
8.
Swiss Dent J ; 129(11): 922-928, 2019 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-31460731

RESUMO

The aim of this study was to evaluate the performance of Galilean and Keplerian loupes in the endodontic lumen with and without integrated light. Although the use of an operating microscope is widely recommended in endodontics it is uncertain whether an adequate loupe system with coaxial light source might replace the microscope for some endodontic work. Twenty-four dentists (age 27­64 years) underwent a miniaturized visual test inside the endodontic lumen of a natural molar: at the canal entrance, 5 mm inside the canal, and at the apex. The tooth was mounted in a phantom head in a simulated clinical setting. The naked eye (negative) and the microscope 6× (positive) served as control groups, and Galilean loupes 2.5× and Keplerian loupes 4.3× with and without a coaxial light source as experimental groups. A structure of 0.05 mm corresponding to the smallest instrument (06) was the threshold for sufficient vision. The loupe type, coaxial light source and the dentists' age had a statistically significant influence at all locations. None of the loupes helped to visualize structures at the apex. At the canal entrance, the visual threshold was reached by dentists < 40 years with Galilean loupes, by dentists ≥ 40 years with Keplerian loupes, with and without coaxial light. Dentists < 40 years detected structures < 0.05 mm inside the root canal with Keplerian loupes and coaxial light. The microscope offered highly superior results. The naked eye was insufficient to reach the visual threshold at any location.


Assuntos
Instrumentos Odontológicos , Odontólogos , Endodontia , Microscopia/instrumentação , Visão Ocular , Adulto , Estudos de Casos e Controles , Assistência Odontológica , Feminino , Humanos , Lentes , Masculino , Pessoa de Meia-Idade , Miniaturização , Testes Visuais
9.
BMC Res Notes ; 12(1): 465, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362792

RESUMO

OBJECTIVES: The aim of the study was to determine the associated risk factors and prevalence of pediculosis capitis among school-aged children in Woreta town, northwest Ethiopia. An institution-based cross-sectional study was carried out on 402 schoolchildren in Woreta town public schools from grades 1 to 4 students conducted from April to June 2018. After selection by simple random sampling, face to face interview and observations were performed using a semi-structured pre-tested questionnaire. Data were entered into EPI Info 7 and exported to SPSS 21 for further analysis. Descriptive results were presented by simple frequency, percentage, and mean. Binary logistic regression was used to identify associated factors. Those variables with a p-value ≤ 0.05 in the multivariable logistic regression were declared as significantly associated with pediculosis capitis infestation. RESULT: The prevalence of pediculosis capitis was 65.7% [95% CI 60.01-70.3%]. Sex of child, age of the child, maternal education, sharing hair comb, knowledge, and attitude towards pediculosis capitis infestation and hygiene practice were significantly associated with pediculosis (a p-value ≤ 0.05). Pediculosis infestation is found to be a major public health problem which demands special attention of the community and the government at large particularly the health sector to reduce the problem.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Infestações por Piolhos/epidemiologia , Pediculus/fisiologia , Animais , Criança , Estudos Transversais , Escolaridade , Etiópia/epidemiologia , Feminino , Humanos , Infestações por Piolhos/parasitologia , Modelos Logísticos , Masculino , Prevalência , Fatores de Risco , Instituições Acadêmicas , Fatores Sexuais , Estudantes , Inquéritos e Questionários
10.
J Res Health Sci ; 19(2): e00446, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31278215

RESUMO

BACKGROUND: Head lice as obligated ectoparasite is a public health concern. We aimed to determine the prevalence of Pediculus humanus capitis as public health concern among girl's primary school in southwest of Iran. STUDY DESIGN: A cross-sectional study. METHODS: This study was conducted in Karoon County, south-west of Khuzestan Province in Iran in 2017-2018. Totally, 851 students were interviewed randomly, examined by a medical entomologist and completed a questionnaire containing 18 questions based on individual, social, economic, cultural and health information. Results were presented as prevalence and percentages for qualitative variables and also, the data were analyzed by univariate logistic and multivariate regression models. RESULTS: About 199 (23.38%) girls were infected by head lice. Univariate logistic regression indicated that the prevalence of pediculosis was directly associated with the grade of education, father's job, shared personal hygiene products, number of combing, having permanent head cover at home, infection in other members of the family and previous infection. Multivariate logistic regressions for predicting of head lice infection in girl students were reported permanent head cover at home (OR: 1.399, 95% CI: 0.934, 2.097, P=0.104), grade of education (OR: 1.948, 95% CI: 1.307, 2.905, P=0.001), father's job (OR: 2.385, 95% CI: 1.518, 3.750, P<0.001), shared personal hygiene products (OR: 1.817, 95% CI: 1.224, 2.698, P=0.003) and using hair oil (OR: 1.904, 95% CI: 1.279, 2.836, P=0.002) had significant relation with head lice infestation CONCLUSION: Head lice remind as serious health problem in Karoon County, southwest of Iran. Due to high infestation, periodic screening of the student is recommended for early detection and treatment.


Assuntos
Infestações por Piolhos/epidemiologia , Pediculus , Instituições Acadêmicas , Animais , Criança , Estudos Transversais , Família , Feminino , Humanos , Higiene , Irã (Geográfico)/epidemiologia , Infestações por Piolhos/etiologia , Modelos Logísticos , Programas de Rastreamento , Razão de Chances , Fatores de Risco , Fatores Socioeconômicos , Estudantes , Inquéritos e Questionários
11.
Molecules ; 24(13)2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31277470

RESUMO

In recent years, the development of metamaterials and metasurfaces has drawn great attention, enabling many important practical applications. Focusing and lensing components are of extreme importance because of their significant potential practical applications in biological imaging, display, and nanolithography fabrication. Metafocusing devices using ultrathin structures (also known as metasurfaces) with superlensing performance are key building blocks for developing integrated optical components with ultrasmall dimensions. In this article, we review the metamaterial superlensing devices working in transmission mode from the perfect lens to two-dimensional metasurfaces and present their working principles. Then we summarize important practical applications of metasurfaces, such as plasmonic lithography, holography, and imaging. Different typical designs and their focusing performance are also discussed in detail.


Assuntos
Lentes , Nanotecnologia , Óptica e Fotônica , Prata/química , Propriedades de Superfície
12.
Parasit Vectors ; 12(1): 290, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174587

RESUMO

BACKGROUND: Head louse, Pediculus humanus capitis, is an obligatory blood-sucking ectoparasite, distributed worldwide. Phylogenetically, it occurs in five divergent mitochondrial clades (A-E); each exhibiting a particular geographical distribution. Recent studies suggest that, as in the case of body louse, head louse could be a disease vector. We aimed to study the genetic diversity of head lice collected in the Democratic Republic of the Congo (DR Congo) and to screen for louse-borne pathogens in these lice. METHODS: A total of 181 head lice were collected from 27 individuals at the Monkole Hospital Center located in Kinshasa. All head lice were genotyped and screened for the presence of louse-borne bacteria using molecular methods. We searched for Bartonella quintana, Borrelia recurrentis, Rickettsia prowazekii, Anaplasma spp., Yersinia pestis, Coxiella burnetii and Acinetobacter spp. RESULTS: Among these head lice, 67.4% (122/181) belonged to clade A and 24.3% (44/181) belonged to clade D. Additionally, for the first time in this area, we found clade E in 8.3% (15/181) of tested lice, from two infested individuals. Dual infestation with clades A and D was observed for 44.4% individuals. Thirty-three of the 181 head lice were infected only by different bacterial species of the genus Acinetobacter. Overall, 16 out of 27 individuals were infested (59.3%). Six Acinetobacter species were detected including Acinetobacter baumannii (8.3%), Acinetobacter johnsonii (1.7%), Acinetobacter soli (1.7%), Acinetobacter pittii (1.7%), Acinetobacter guillouiae (1.1%), as well as a new potential species named "Candidatus Acinetobacter pediculi". CONCLUSIONS: To our knowledge, this study reports for the first time, the presence of clade E head lice in DR Congo. This study is also the first to report the presence of Acinetobacter species DNAs in human head lice in DR Congo.


Assuntos
Bactérias/genética , Variação Genética , Pediculus/genética , Acinetobacter/genética , Acinetobacter/patogenicidade , Animais , Bactérias/isolamento & purificação , Bactérias/patogenicidade , Bartonella quintana/genética , Bartonella quintana/patogenicidade , Borrelia/genética , Borrelia/patogenicidade , Coxiella burnetii/genética , Coxiella burnetii/patogenicidade , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , República Democrática do Congo , Vetores de Doenças , Genótipo , Humanos , Infestações por Piolhos/microbiologia , Pediculus/microbiologia , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Yersinia pestis/genética , Yersinia pestis/patogenicidade
13.
Appl Spectrosc ; 73(8): 936-944, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31149836

RESUMO

Hypericin (Hyp) is a natural compound with interesting photophysical and pharmacological properties, which has been used in photodynamic therapy and photodynamic inactivation of microorganisms. Its synthesis is based on a series of chemical processes that ends with a light-drug interaction by the photoconversion of protohypericin (pHyp) to Hyp. Although this photosensitizer is used in a variety of medical applications, the photophysical and photochemical mechanisms involved in the final step related to the photo production of Hyp are not completely understood at the molecular level. Protohypericin concentration, solvents, light irradiation under different wavelengths, and a sort of variables could play an important role in predicting the yielding of this photoconversion process. Here, we used the high-sensitive and remote measurement characteristics of the time-resolved thermal lens technique to investigate the relation between the light-induced photoconversion rate of pHyp to Hyp and the initial concentration pHyp. The results show a linear dependence of the photoreaction rate with the concentration of pHyp, indicating that the overall reaction process includes steps comprising the formation of distinct intermediate species. We demonstrate the applicability of the thermal lens technique for the photochemical characterization of photosensitive drugs at low concentration levels.


Assuntos
Perileno/análogos & derivados , Fármacos Fotossensibilizantes/síntese química , Lentes , Perileno/síntese química , Perileno/química , Fotoquimioterapia
14.
J Am Dent Assoc ; 150(8): 689-694, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229256

RESUMO

BACKGROUND: Magnification loupes are not disposable and must be cleaned and disinfected between each patient. In this pilot study, the authors determined the efficacy of infection-control procedures used by dental students between patients. METHODS: Visibly clean loupes owned and used by 25 dental students were swabbed for bacteria using a standard microbiology method at baseline and then cleaned with surface disinfectant before they were returned. The students then used and disinfected their loupes for 5 days as they treated patients, after which time the loupes were retrieved and swabbed again. After the samples had been cultured, the numbers of aerobic and anaerobic colony-forming units (CFUs) were enumerated. The authors report the contamination levels at baseline, after cleaning, and after being used for 5 days. RESULTS: At baseline, the number of CFUs ranged from 0 through more than 100. When used according to the manufacturers' instructions, the disinfectant reduced the count to no more than 2 CFUs. After the loupes were used for 5 days, 20% of loupes were highly contaminated (> 100 CFUs), 20% were moderately contaminated (20-100 CFUs), and 60% had less than 20 CFUs. Students who performed a restoration on day 5 were 12 times more likely (P < .01) to have loupes contaminated with aerobic bacteria than those who had not performed a restoration on day 5. CONCLUSIONS: The recommended prophylaxis and disinfection protocol worked well when used correctly, but it was likely that the protocol often was not followed properly or consistently. PRACTICAL IMPLICATIONS: Visibly clean loupes may be a source of cross-contamination.


Assuntos
Desinfecção , Lentes , Humanos , Projetos Piloto , Estudantes de Odontologia
15.
J Opt Soc Am A Opt Image Sci Vis ; 36(5): 722-730, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31044998

RESUMO

An adaptive optics visual simulator (AOVS) with an extended dioptric range was developed, allowing measuring and correcting aberrations in a majority of highly ametropic eyes. In the instrument, a tunable lens is used for defocus correction, while a liquid-crystal-on-silicon spatial light modulator is used for compensating or inducing any other aberration. The instrument incorporates a digital projector, which uses a micromirror array to display the stimuli. A motorized diaphragm enables operation for any physiological pupil size. A full description of the instrument and its calibration are provided, together with the results obtained in seven highly myopic subjects with refraction of -7.2±1.8 D (mean±SD). Refraction obtained with the instrument was compared to the standard refraction prescribed by trial lenses. When using the refraction obtained by the AOVS, the visual acuity (VA) exhibited an average increase of 0.21 (decimal scale). The visual impact of correcting high-order aberrations is presented in three subjects, whose VAs slightly improved with the correction. High myopes are able to benefit from the improved refraction assessment. The new instrument creates a possibility for a wide number of new experiments, especially for eyes exhibiting large refractive errors, where previous AO instruments failed to operate.


Assuntos
Lentes , Dispositivos Ópticos , Adulto , Desenho de Equipamento , Humanos , Miopia/fisiopatologia , Acuidade Visual , Adulto Jovem
16.
Cornea ; 38(8): 948-950, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31045959

RESUMO

PURPOSE: To report the clinical features and outcomes of toxic keratitis after application of powdered custard apple seeds for hair washing for head lice infestation. METHODS: Retrospective review of all patients with toxic keratitis after application of powdered custard apple seed for head lice infestation during the time period from January 2015 to December 2017. Demographic details, clinical features, and visual outcomes were documented. RESULTS: Thirty-one eyes of 19 patients with toxic keratitis after application of crushed custard apple seeds for head lice infestation were included in the study. Eighteen females and 1 male with a median age of 14 years [interquartile range (IQR) 12-34 years] presented with severe epiphora, congestion, photophobia, and defective vision (median logMar visual acuity 0.4, IQR 0.2-0.8) after application of custard apple seed powder for hair washing. Ten eyes (32.2%) had an epithelial defect (median size 9 mm, IQR 5-12 mm), and 21 (67.7%) eyes had punctate epithelial erosions. All the patients were treated with topical antibiotics, and at 3 days follow-up, all of them had resolution of symptoms and signs with a median logarithm of the minimum angle of resolution (logMAR) visual acuity of 0 (IQR 0-0.2). CONCLUSIONS: Health education about the harmful effect of this traditional practice for head lice infestation will prevent further similar events.


Assuntos
Annona/toxicidade , Ceratite/induzido quimicamente , Infestações por Piolhos/tratamento farmacológico , Pediculus/efeitos dos fármacos , Administração Oftálmica , Adolescente , Adulto , Animais , Antibacterianos/uso terapêutico , Criança , Dor Ocular/induzido quimicamente , Dor Ocular/diagnóstico , Dor Ocular/tratamento farmacológico , Feminino , Humanos , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Doenças do Aparelho Lacrimal/induzido quimicamente , Doenças do Aparelho Lacrimal/diagnóstico , Doenças do Aparelho Lacrimal/tratamento farmacológico , Masculino , Ofloxacino/uso terapêutico , Fotofobia/induzido quimicamente , Fotofobia/diagnóstico , Fotofobia/tratamento farmacológico , Estudos Retrospectivos , Transtornos da Visão/induzido quimicamente , Transtornos da Visão/diagnóstico , Transtornos da Visão/tratamento farmacológico , Adulto Jovem
17.
Parasit Vectors ; 12(1): 201, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053177

RESUMO

BACKGROUND: Pediculus humanus, the human body louse, is widespread where overcrowding and lack of hygiene are present, in areas of the world affected by poverty, war, famine and presence of refugees. It has recently been considered re-emerging among homeless populations in developed countries. In Italy, it was last reported in 1945. Pediculus humanus is a vector of highly relevant human pathogens. METHODS: In October 2018, a woman found small insects on a T-shirt bought second-hand in a local street market in a village 35 km south of Rome (central Italy). Insects were identified both morphologically and by molecular analysis. Moreover, they were analyzed molecularly for the presence of Rickettsia prowazekii, Borrelia recurrentis, Bartonella quintana, Coxiella burnetii and Yersinia pestis. RESULTS: Morphological and molecular analyses of the insects identified them as 26 lice (12 females, 10 males and 4 nymphs) of the species P. humanus. Many nits were found on the T-shirt seams. DNA of the investigated pathogens was not detected in any of the lice. CONCLUSIONS: The exceptionality of the described case lies both in the report of P. humanus from a country where it had not been reported since 1945, and in its finding from second-hand clothes for sale in a market, constituting a potential source of infection for people buying this type of goods. The question arises, how did adults and nits of P. humanus infest clothes for sale on a market stall in a country where it had not been reported for decades. Given that the body louse requires frequent blood meals to survive and develop, its arrival on clothes imported from abroad is highly improbable. Hence, it must be presumed that people infected with the human body louse are present in Italy. This report points out a serious regulatory problem regarding the management of second-hand clothes prior to sale and, more generally, of controls in street markets.


Assuntos
Vestuário/economia , Insetos Vetores/classificação , Pediculus/classificação , Animais , Feminino , Humanos , Insetos Vetores/genética , Insetos Vetores/fisiologia , Itália , Masculino , Pediculus/genética , Pediculus/fisiologia , Filogenia
18.
PLoS One ; 14(5): e0217074, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31125360

RESUMO

Previous studies have shown that the size of the leftward bias after exposure to rightward prism-deviation (the prismatic after-effect) depends on the degree of rightward prism-deviation as well as the type of visual feedback receives during exposure to prism-deviation. In this study, we tested if it was possible to obtain a leftward bias in pointing precision using two different methods of creating diverted visual input by simulating a rightward prism diversion of visual input in immersive virtual reality. We compared the results to the leftward bias in pointing precision obtained after exposure to standard prism goggles deviating visual input 10 degrees to the right. Twenty healthy participants were subjected to one session of standard prism adaptation therapy under three different conditions of deviated visual input: 1) created by imitating a 10 degree leftward rotation of the head (VRR), 2) created by imitating a 2D leftward horizontal displacement of 10 degrees (VRS) and 3) a control condition using real right-deviating prisms (PCP). The study showed that the simulated prisms in the VRR and VRS conditions produced deviations in pointing precision of a similar size. However, exposure to the VRS and VRR conditions both produced larger prismatic after-effects than the exposure to real prism goggles. This research is important for the development and use of virtual reality systems in the rehabilitation of neglect after brain injury as it emphasizes that the adjustment to deviated visual input may be affected positively by the use of immersive virtual reality technology.


Assuntos
Adaptação Fisiológica/fisiologia , Pós-Efeito de Figura/fisiologia , Lateralidade Funcional/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Espacial/fisiologia , Realidade Virtual , Percepção Visual/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Lentes , Masculino , Estimulação Luminosa
19.
Ophthalmic Physiol Opt ; 39(3): 141-147, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30994200

RESUMO

PURPOSE: Screening for uncorrected hyperopia in school children is important given its association with poorer visual function and academic performance. However, standard distance visual acuity screening may not detect low to moderate hyperopia. The plus lens test is used to screen for hyperopia in many school screening protocols, but has not been well validated. The current study investigated the effectiveness of the plus lens test to identify hyperopia in school children. METHODS: Participants included Grade 2 school children. Monocular distance visual acuity (logMAR letter chart) was measured unaided, and then through a +1.50D lens, known as the plus lens test. Cycloplegic refraction was undertaken to classify moderate hyperopia (≥+2.00D). Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were calculated for commonly used cut-offs for the plus lens test: 6/6, 6/9 and less than two lines difference between unaided acuity and acuity through the plus lens test. RESULTS: The sample included 59 children (mean age 7.2 ± 0.4 years). Fourteen (24%) children were classified as having uncorrected hyperopia. The sensitivity and specificity of the +1.50 plus lens test for identifying hyperopia were 0% and 98% respectively for a 6/6 cut-off, 29% and 91% for 6/9 cut-off, and 50% and 76% for a <2 line reduction between unaided acuity and acuity through the plus lens test. Receiver Operating Curve (ROC) analysis revealed area under curves of 0.69 based on acuity through the plus lens test, and 0.65 for a reduction in acuity through the plus lens test. CONCLUSIONS: The plus lens test has low sensitivity for detecting uncorrected hyperopia using traditional cut-offs of 6/9 or better. This raises questions about the role of the plus lens test in school screening batteries.


Assuntos
Hiperopia/diagnóstico , Lentes , Óptica e Fotônica/métodos , Refração Ocular/fisiologia , Seleção Visual/métodos , Acuidade Visual/fisiologia , Criança , Feminino , Humanos , Masculino
20.
Ultramicroscopy ; 202: 76-86, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31003162

RESUMO

Multilayer normal-incidence mirrors allow the numerical aperture (NA=0.3-0.5) of a projection lens to be significantly increased in the spectral ranges of the water (λ = 2.3-4.4 nm) and carbon (λ = 4.4-7 nm) windows, in comparison with the Fresnel zone plates. The low depth of focus of high-aperture optics (tens of nm) makes it possible to use z-tomography to reconstruct the structure of samples in soft X-ray microscopy. The presence of strong absorption prevents the direct use of a powerful deconvolution apparatus developed for fluorescence optical microscopy to improve the clarity of the image. In this article, the "intensity restoration algorithm" is proposed that takes into account the absorption effect before standard deconvolution. For an imagine lens with NA = 0.3 and a working wavelength of 3.37 nm, the results of simulating an image of a protein cell and its deconvolutionary processing are presented, before and after applying the proposed method. After its application, the deconvolution efficiency is significantly increased. A "full-period" resolution of 40 nm was obtained for the image of a simulated protein cell.


Assuntos
Microscopia de Fluorescência/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Desenho de Equipamento/métodos , Processamento de Imagem Assistida por Computador/métodos , Lentes , Óptica e Fotônica/métodos , Raios X
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