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Sample records for lens nucleus ages

  1. Effect of chronic smoking on lens nucleus as assessed by Pentacam HR lens densitometry in young adults.

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    Pekel, Gökhan; Cetin, Ebru Nevin; Acer, Semra; Yagci, Ramazan; Altintas, Seher; Ongun, Gülin Tugba

    2014-06-01

    To evaluate the effects of chronic tobacco smoking on lens nucleus by Pentacam HR lens densitometry (LD) in young adults. Prospective cross-sectional case series. Thirty subjects (23 M, 7 F) who were chronic cigarette smokers (≥10 cigarettes/day for at least 2 years) (group 1) and another 30 subjects (23 M, 7 F) who did not smoke (group 2), were included in this study. The patients were matched for age and sex between the groups. The exclusion criteria were any history of ocular surgery, any systemic disorders and any ocular diseases except for mild refractive disorders. Lens densitometry measurements were done with the Pentacam HR (Oculus, Wetzlar, Germany). The Schirmer test and pachymetry measurements were also performed. Mean age of the patients for both groups was 28.90 ± 8.20 years (range: 18-40 years). Mean lens densitometry (LD) measurements of Group 1 (chronic cigarette smoking group) were higher than those of Group 2 (control group) in all LD techniques; however only mean "peak" LD measurements showed a statistically significant difference between these two groups (Group 1: 8.67 ± 0.61, Group 2: 8.44 ± 0.70, p = 0.04). The mean Schirmer test value was 12.43 ± 5.60 mm in Group 1 and 13.00 ± 4.26 mm in Group 2 (p = 0.55). The mean central corneal thickness (CCT) value was 564.23 ± 34.61 µm in Group 1 and 550.47 ± 32.94 µm in Group 2 (p = 0.03). The Pentacam HR LD seems to be an important option for the evaluation of lens nucleus in young adults, because it gives objective and quantitative data. Although chronic smoking increases lens nucleus density in young adults, the effect is not statistically significant when compared with the control group.

  2. A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

    Science.gov (United States)

    Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

    2012-01-01

    It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear

  3. Disassembly of the lens fiber cell nucleus to create a clear lens: the p27 descent

    Science.gov (United States)

    The eye lens is unique among tissues: it is transparent, does not form tumors, and the majority of its cells degrade their organelles, including their cell nuclei. A mystery for over a century, there has been considerable recent progress in elucidating mechanisms of lens fiber cell denucleation (LFC...

  4. A Class I UV-blocking (senofilcon A) soft contact lens prevents UVA-induced yellow fluorescence and NADH loss in the rabbit lens nucleus in vivo.

    Science.gov (United States)

    Giblin, Frank J; Lin, Li-Ren; Simpanya, Mukoma F; Leverenz, Victor R; Fick, Catherine E

    2012-09-01

    It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm(2) on the cornea) for 1 h using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 h. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear

  5. Human lens colouration, age and cataract

    International Nuclear Information System (INIS)

    Truscott, R.J.W.; Garner, B.; Hood, B.

    1999-01-01

    Full text: The human lens biosynthesises UV filter compounds which effectively remove light in the 300-400nm band. These chemicals are present either as an aid to visual acuity, or to filter out damaging UV radiation. The primate UV filters are 3-hydroxykynurenine analogues derived from the metabolism of tryptophan. We have recently demonstrated that these endogenous UV filters are not innocuous, but are in fact capable of binding to proteins, including the crystalline proteins which make up the bulk of the lens. Thus, over time, the levels of protein - bound UV filters increase and this results in the human lens becoming progressively more yellow as we age. This colouration affects our colour vision and it may also be responsible for the brown colour of lenses which is the hallmark of age-related nuclear cataract. An understanding of the intrinsic instability of the endogenous UV filters, combined with changes in the internal transport of these and other small molecular weight compounds including antioxidants, such as glutathione, is allowing us to gain an insight into the processes responsible for the development of age-related cataract: the major cause of world blindness

  6. Comparative analysis of the nuclear lens opalescence by the Lens Opacities Classification System III with nuclear density values provided by Oculus Pentacam: a cross-section study using Pentacam Nucleus Staging software.

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    Magalhães, Fernanda Pedreira; Costa, Elaine Fiod; Cariello, Angelino Júlio; Rodrigues, Eduardo Buchele; Hofling-Lima, Ana Luisa

    2011-01-01

    To compare the clinical classification of cataract using the Lens Opacities Classification System (LOCS) III with the mean values of lens density provided by the Pentacam Scheimpflug System in nuclear cataracts. One hundred and one eyes from 101 patients with age-related nuclear cataract were submitted to clinical examination for lens grading score using LOCS III. According to LOCS III, nuclear opalescence was divided in six groups. Patients were evaluated by the Pentacam Scheimpflug System for the mean lens density using the Pentacam lens densitometry program (PLDP), the Pentacam Nucleus Staging (PNS) mean value and the PNS cataract grading score. A positive correlation between the mean values of lens density and LOCS III classification, considering groups 1 to 5, could be noticed with PLDP and PNS mean value. The mean values between the groups were similar using the PLDP and the PNS mean value. However, when the PNS cataract grading score was evaluated, there was low correspondence with LOCS III classification. Pentacam Scheimpflug device offers an objective measure of the lens nuclear density on nuclear cataracts. PLDP and the PNS mean value were both useful to evaluate age-related nuclear cataract up to LOCS III group 5.

  7. Comparative analysis of the nuclear lens opalescence by the Lens Opacities Classification System III with nuclear density values provided by Oculus Pentacam: a cross-section study using Pentacam Nucleus Staging software

    Directory of Open Access Journals (Sweden)

    Fernanda Pedreira Magalhães

    2011-04-01

    Full Text Available PURPOSE: To compare the clinical classification of cataract using the Lens Opacities Classification System (LOCS III with the mean values of lens density provided by the Pentacam Scheimpflug System in nuclear cataracts. METHODS: One hundred and one eyes from 101 patients with age-related nuclear cataract were submitted to clinical examination for lens grading score using LOCS III. According to LOCS III, nuclear opalescence was divided in six groups. Patients were evaluated by the Pentacam Scheimpflug System for the mean lens density using the Pentacam lens densitometry program (PLDP, the Pentacam Nucleus Staging (PNS mean value and the PNS cataract grading score. RESULTS: A positive correlation between the mean values of lens density and LOCS III classification, considering groups 1 to 5, could be noticed with PLDP and PNS mean value. The mean values between the groups were similar using the PLDP and the PNS mean value. However, when the PNS cataract grading score was evaluated, there was low correspondence with LOCS III classification. CONCLUSION: Pentacam Scheimpflug device offers an objective measure of the lens nuclear density on nuclear cataracts. PLDP and the PNS mean value were both useful to evaluate age-related nuclear cataract up to LOCS III group 5.

  8. Polymorphisms in sodium-dependent vitamin C transporter genes and plasma, aqueous humor and lens nucleus ascorbate concentrations in an ascorbate depleted setting.

    Science.gov (United States)

    Senthilkumari, Srinivasan; Talwar, Badri; Dharmalingam, Kuppamuthu; Ravindran, Ravilla D; Jayanthi, Ramamurthy; Sundaresan, Periasamy; Saravanan, Charu; Young, Ian S; Dangour, Alan D; Fletcher, Astrid E

    2014-07-01

    We have previously reported low concentrations of plasma ascorbate and low dietary vitamin C intake in the older Indian population and a strong inverse association of these with cataract. Little is known about ascorbate levels in aqueous humor and lens in populations habitually depleted of ascorbate and no studies in any setting have investigated whether genetic polymorphisms influence ascorbate levels in ocular tissues. Our objectives were to investigate relationships between ascorbate concentrations in plasma, aqueous humor and lens and whether these relationships are influenced by Single Nucleotide Polymorphisms (SNPs) in sodium-dependent vitamin C transporter genes (SLC23A1 and SLC23A2). We enrolled sixty patients (equal numbers of men and women, mean age 63 years) undergoing small incision cataract surgery in southern India. We measured ascorbate concentrations in plasma, aqueous humor and lens nucleus using high performance liquid chromatography. SLC23A1 SNPs (rs4257763, rs6596473) and SLC23A2 SNPs (rs1279683 and rs12479919) were genotyped using a TaqMan assay. Patients were interviewed for lifestyle factors which might influence ascorbate. Plasma vitamin C was normalized by a log10 transformation. Statistical analysis used linear regression with the slope of the within-subject associations estimated using beta (β) coefficients. The ascorbate concentrations (μmol/L) were: plasma ascorbate, median and inter-quartile range (IQR), 15.2 (7.8, 34.5), mean (SD) of aqueous humor ascorbate, 1074 (545) and lens nucleus ascorbate, 0.42 (0.16) (μmol/g lens nucleus wet weight). Minimum allele frequencies were: rs1279683 (0.28), rs12479919 (0.30), rs659647 (0.48). Decreasing concentrations of ocular ascorbate from the common to the rare genotype were observed for rs6596473 and rs12479919. The per allele difference in aqueous humor ascorbate for rs6596473 was -217 μmol/L, p humor ascorbate were higher for the GG genotype of rs6596473: GG, β = 1460 compared to

  9. Chemical and physical properties of the normal and aging lens: spectroscopic (UV, fluorescence, phosphorescence, and NMR) analyses

    International Nuclear Information System (INIS)

    Lerman, S.

    1987-01-01

    In vitro [UV absorption, fluorescence, phosphorescence, and nuclear magnetic resonance (NMR)] spectroscopic studies on the normal human lens demonstrate age-related changes which can be correlated with biochemical and photobiologic mechanisms occurring during our lifetime. Chronic cumulative UV exposure results in an age-related increase of photochemically induced chromophores and in color of the lens nucleus. This enables the lens to filter the incident UV radiation, thereby protecting the underlying aging retina from UV photodamage. We have measured the age-related increase in lens fluorescence in vivo on more than 300 normal subjects (1st to 9th decade) by UV slitlamp densitography. These data show a good correlation with the in vitro lens fluorescence studies reported previously and demonstrate that molecular photodamage can be monitored in the lens. In vitro NMR (human and animal lenses) and in vivo experiments currently in progress are rapidly elucidating the physicochemical basis for transparency and the development of light scattering areas. Surface scanning NMR can monitor organophosphate metabolism in the ocular lens in vivo as well as in vitro. These studies demonstrate the feasibility of using biophysical methods (optical spectroscopy and NMR analyses) to delineate age-related parameters in the lens, in vivo as well as in vitro. 46 references

  10. Properties of Fiber Cell Plasma Membranes Isolated from the Cortex and Nucleus of the Porcine Eye Lens

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    Mainali, Laxman; Raguz, Marija; O’Brien, William J.; Subczynski, Witold K.

    2012-01-01

    The organization and physical properties of the lipid bilayer portion of intact cortical and nuclear fiber cell plasma membranes isolated from the eyes lenses of two-year-old pigs were studied using electron paramagnetic resonance (EPR) spin-labeling. Membrane fluidity, hydrophobicity, and the oxygen transport parameter (OTP) were assessed from the EPR spectra of precisely positioned spin labels. Intact cortical and nuclear membranes, which include membrane proteins, were found to contain three distinct lipid environments. These lipid environments were termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain (lipids in protein aggregates). The amount of boundary and trapped lipids was greater in intact nuclear membranes than in cortical membranes. The properties of intact membranes were compared with the organization and properties of lens lipid membranes made of the total lipid extracts from the lens cortex or nucleus. In cortical lens lipid membranes, only one homogenous environment was detected, which was designated as a bulk lipid domain (phospholipid bilayer saturated with cholesterol). Lens lipid membranes prepared from the lens nucleus possessed two domains, assigned as a bulk lipid domain and a cholesterol bilayer domain (CBD). In intact nuclear membranes, it was difficult to discriminate the CBD, which was clearly detected in nuclear lens lipid membranes because the OTP measured in the CBD is the same as in the domain formed by trapped lipids. The two domains unique to intact membranes—namely, the domain formed by boundary lipids and the domain formed by trapped lipids—were most likely formed due to the presence of membrane proteins. It is concluded that formation of rigid and practically impermeable domains is enhanced in the lens nucleus, indicating changes in membrane composition that may help to maintain low oxygen concentration in this lens region. PMID:22326289

  11. SURGICAL INTERVENTION AND ACCOMMODATIVE RESPONSES: I. CENTRIPETAL CILIARY BODY, CAPSULE AND LENS MOVEMENT IN RHESUS MONKEYS OF VARYING AGE

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    Croft, Mary Ann; Mcdonald, Jared P.; James, Rebecca J.; Heatley, Gregg A.; Lin, Ting-Li; Lütjen-Drecoll, Elke; Kaufman, Paul L.

    2009-01-01

    Purpose To determine how surgically altering the normal relationship between the lens and the ciliary body in rhesus monkeys affects centripetal ciliary body and lens movement. Methods In 18 rhesus monkey eyes (aged 6–27 years), accommodation was induced before and after surgery by electrical stimulation of the Edinger-Westphal (E–W) nucleus. Accommodative amplitude was measured by coincidence refractometry. Goniovideography was performed before and after intra- and extra-capsular lens extraction (ICLE, ECLE) and anterior regional zonulolysis. Centripetal lens/capsule movements, centripetal ciliary process (CP) movements, and circumlental space were measured by computerized image analysis of the goniovideography images. Results Centripetal accommodative CP and capsule movement increased in velocity and amplitude post-ECLE compared to pre-ECLE regardless of age (n=5). The presence of the lens substance retarded capsule movement by ~21% in the young eyes and by ~62% in the older eyes. Post-ICLE compared to pre-ICLE centripetal accommodative CP movement was dampened in all eyes in which the anterior vitreous was disturbed (n=7), but not in eyes in which the anterior vitreous was left intact (n=2). Following anterior regional zonulolysis (n=4), lens position shifted toward the lysed quadrant during accommodation. Conclusions The presence of the lens substance, capsule zonular attachments, and Wiegers ligament may play a role in centripetal CP movement. The capsule is still capable of centripetal movement in the older eye (although at a reduced capacity) and may have the ability to produce ~6 diopters of accommodation in the presence of a normal young crystalline lens or a similar surrogate. PMID:18552393

  12. D-aspartic acid in aged mouse skin and lens

    International Nuclear Information System (INIS)

    Fujii, Noriko; Muraoka, Shiro; Harada, Kaoru; Tamanoi, Itsuro; Joshima, Hisamasa; Kashima, Masatoshi.

    1987-01-01

    D-aspartic acid (D-Asp) was detected in the skin and lens from naturally aged mice. An analysis of the amino acid composition indicated that D-Asp did not derive from collagen. An immunological analysis using Oucterlony's agar diffusion method also confirmed that the protein containing D-Asp was not a serum protein. The process producing D-Asp is regarded as one other than racemization because the life span of mice is not long enough to permit D-Asp by racemization. Continuous low-dose-rate gamma-irradiation (37R per day) for 102 to 112 days did not increase significantly the amount of D-Asp in skin and lens of mice. (author)

  13. Thioredoxin, thioredoxin reductase, and alpha-crystallin revive inactivated glyceraldehyde 3-phosphate dehydrogenase in human aged and cataract lens extracts.

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    Yan, Hong; Lou, Marjorie F; Fernando, M Rohan; Harding, John J

    2006-10-02

    To investigate whether mammalian thioredoxin (Trx) and thioredoxin reductase (TrxR), with or without alpha-crystallin can revive inactivated glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in both the cortex and nucleus of human aged clear and cataract lenses. The lens cortex (including capsule-epithelium) and the nucleus were separated from human aged clear and cataract lenses (grade II and grade IV) with similar average age. The activity of GAPDH in the water-soluble fraction after incubation with or without Trx or/and TrxR for 60 min at 30 degrees C was measured spectrophotometrically. In addition, the effect of a combination of Trx/TrxR and bovine lens alpha-crystallin was investigated. GAPDH activity was lower in the nucleus of clear lenses than in the cortex, and considerably diminished in the cataractous lenses, particularly in the nucleus of cataract lenses grade IV. Trx and TrxR were able to revive the activity of GAPDH markedly in both the cortex and nucleus of the clear and cataract lenses. The percentage increase of activity in the cortex of the clear lenses was less than that of the nucleus in the presence of Trx and TrxR, whereas it was opposite in the cataract lenses. The revival of activity in both the cortex and nucleus from the cataract lenses grade II was higher than that of the grade IV. Moreover, Trx alone, but not TrxR, efficiently enhanced GAPDH activity. The combination of Trx and TrxR had greater effect than that of either alone. In addition, alpha(L)-crystallin enhanced the activity in the cortex of cataract grade II with Trx and TrxR present. However, it failed to provide a statistically significant increase of activity in the nucleus. This is the first evidence to show that mammalian Trx and TrxR are able to revive inactivated GAPDH in human aged clear and cataract lenses, and alpha-crystallin helped this effect. The inactivation of GAPDH during aging and cataract development must be caused in part by disulphide formation and in part by

  14. Lens aging in relation to nutritional determinants and possible risk factors for age-related cataract

    NARCIS (Netherlands)

    Berendschot, T.T.J.M.; Broekmans, W.M.R.; Klöpping-Ketelaars, I.A.A.; Kardinaal, A.F.M.; Poppel, G. van; Norren, D. van

    2002-01-01

    Objective: To investigate whether nutritional factors and possible risk factors for cataract influence the lens optical density (LOD). Design: Three hundred seventy-six subjects, aged 18 to 75 years, were recruited. In a cross-sectional design, serum was analyzed for lutein, zeaxanthin, vitamin C,

  15. Age-related changes in spectral transmittance of the human crystalline lens in situ.

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    Sakanishi, Yoshihito; Awano, Masakazu; Mizota, Atsushi; Tanaka, Minoru; Murakami, Akira; Ohnuma, Kazuhiko

    2012-01-01

    It was the aim of this study to measure spectral transmission of the human crystalline lens in situ. The crystalline lens was illuminated by one of four light-emitting diodes of different colors. The relative spectral transmittance of the human crystalline lens was measured with the Purkinje-Sanson mirror images over a wide range of ages. The study evaluated 36 crystalline lenses of 28 subjects aged 21-76 years. There was a significant correlation between the age and spectral transmittance for blue light. Spectral transmittance of the crystalline lens in situ could be measured with Purkinje-Sanson mirror images. Copyright © 2012 S. Karger AG, Basel.

  16. The effect of lens aging and cataract surgery on circadian rhythm.

    Science.gov (United States)

    Yan, Shen-Shen; Wang, Wei

    2016-01-01

    Many organisms have evolved an approximately 24-hour circadian rhythm that allows them to achieve internal physiological homeostasis with external environment. Suprachiasmatic nucleus (SCN) is the central pacemaker of circadian rhythm, and its activity is entrained to the external light-dark cycle. The SCN controls circadian rhythm through regulating the synthesis of melatonin by pineal gland via a multisynaptic pathway. Light, especially short-wavelength blue light, is the most potent environmental time cue in circadian photoentrainment. Recently, the discovery of a novel type of retinal photoreceptors, intrinsically photosensitive retinal ganglion cells, sheds light on the mechanism of circadian photoentrainment and raises concerns about the effect of ocular diseases on circadian system. With age, light transmittance is significantly decreased due to the aging of crystalline lens, thus possibly resulting in progressive loss of circadian photoreception. In the current review, we summarize the circadian physiology, highlight the important role of light in circadian rhythm regulation, discuss about the correlation between age-related cataract and sleep disorders, and compare the effect of blue light- filtering intraocular lenses (IOLs) and ultraviolet only filtering IOLs on circadian rhythm.

  17. Age-dependent Fourier model of the shape of the isolated ex vivo human crystalline lens.

    Science.gov (United States)

    Urs, Raksha; Ho, Arthur; Manns, Fabrice; Parel, Jean-Marie

    2010-06-01

    To develop an age-dependent mathematical model of the zero-order shape of the isolated ex vivo human crystalline lens, using one mathematical function, that can be subsequently used to facilitate the development of other models for specific purposes such as optical modeling and analytical and numerical modeling of the lens. Profiles of whole isolated human lenses (n=30) aged 20-69, were measured from shadow-photogrammetric images. The profiles were fit to a 10th-order Fourier series consisting of cosine functions in polar-co-ordinate system that included terms for tilt and decentration. The profiles were corrected using these terms and processed in two ways. In the first, each lens was fit to a 10th-order Fourier series to obtain thickness and diameter, while in the second, all lenses were simultaneously fit to a Fourier series equation that explicitly include linear terms for age to develop an age-dependent mathematical model for the whole lens shape. Thickness and diameter obtained from Fourier series fits exhibited high correlation with manual measurements made from shadow-photogrammetric images. The root-mean-squared-error of the age-dependent fit was 205 microm. The age-dependent equations provide a reliable lens model for ages 20-60 years. The contour of the whole human crystalline lens can be modeled with a Fourier series. Shape obtained from the age-dependent model described in this paper can be used to facilitate the development of other models for specific purposes such as optical modeling and analytical and numerical modeling of the lens. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Crystalline lens paradoxes revisited: significance of age-related restructuring of the GRIN.

    Science.gov (United States)

    Sheil, Conor J; Goncharov, Alexander V

    2017-09-01

    The accommodating volume-constant age-dependent optical (AVOCADO) model of the crystalline lens is used to explore the age-related changes in ocular power and spherical aberration. The additional parameter m in the GRIN lens model allows decoupling of the axial and radial GRIN profiles, and is used to stabilise the age-related change in ocular power. Data for age-related changes in ocular geometry and lens parameter P in the axial GRIN profile were taken from published experimental data. In our age-dependent eye model, the ocular refractive power shows behaviour similar to the previously unexplained "lens paradox". Furthermore, ocular spherical aberration agrees with the data average, in contrast to the proposed "spherical aberration paradox". The additional flexibility afforded by parameter m , which controls the ratio of the axial and radial GRIN profile exponents, has allowed us to study the restructuring of the lens GRIN medium with age, resulting in a new interpretation of the origin of the power and spherical aberration paradoxes. Our findings also contradict the conceptual idea that the ageing eye is similar to the accommodating eye.

  19. Rate of lens lesion development and the age of mice at time of irradiation

    International Nuclear Information System (INIS)

    Gajewski, A.K.; Majewska, K.; Slowikowska, M.G.

    1976-01-01

    The rate of lens lesion development has been studied in mice irradiated at different age ranging from one day up to one year old mice. The time needed for the first appearance of lens lesion was shortest in groups of mice irradiated at the age of one, two and three days of life, and longest in groups of mice irradiated at the age of 5 days, 1 week and 2 weeks of life. The time needed for the first appearance of lens lesion for mice irradiated between the third week and one year of life was constant. It was longer than for mice irradiated during the first three days of life and shorter than for mice irradiated at 5 up to 14 days of life. In all but one irradiated groups the age at which the first lens lesion occurred differed significantly from the age at which the first senile changes occurred in the lens of control mice. The one exception was the group of mice irradiated at the age of one year. (author)

  20. Hyperelastic modelling of the crystalline lens: Accommodation and presbyopia

    Science.gov (United States)

    Lanchares, Elena; Navarro, Rafael; Calvo, Begoña

    2012-01-01

    Purpose The modification of the mechanical properties of the human crystalline lens with age can be a major cause of presbyopia. Since these properties cannot be measured in vivo, numerical simulation can be used to estimate them. We propose an inverse method to determine age-dependent change in the material properties of the tissues composing the human crystalline lens. Methods A finite element model of a 30-year-old lens in the accommodated state was developed. The force necessary to achieve full accommodation in a 30-year-old lens of known external geometry was computed using this model. Two additional numerical models of the lens corresponding to the ages of 40 and 50 years were then built. Assuming that the accommodative force applied to the lens remains constant with age, the material properties of nucleus and cortex were estimated by inverse analysis. Results The zonular force necessary to reshape the model of a 30-year-old lens from the accommodated to the unaccommodated geometry was 0.078 newton (N). Both nucleus and cortex became stiffer with age. The stiffness of the nucleus increased with age at a higher rate than the cortex. Conclusions In agreement with the classical theory of Helmholtz, on which we based our model, our results indicate that a major cause of presbyopia is that both nucleus and cortex become stiffer with age; therefore, a constant value of the zonular forces with aging does not achieve full accommodation, that is, the accommodation capability decreases.

  1. Different alpha crystallin expression in human age-related and congenital cataract lens epithelium.

    Science.gov (United States)

    Yang, Jing; Zhou, Sheng; Guo, Minfei; Li, Yuting; Gu, Jianjun

    2016-05-28

    The purpose of this study was to investigate the different expressions of αA-crystallin and αB-crystallin in human lens epithelium of age-related and congenital cataracts. The central part of the human anterior lens capsule approximately 5 mm in diameter together with the adhering epithelial cells, were harvested and processed within 6 hours after cataract surgery from age-related and congenital cataract patients or from normal eyes of fresh cadavers. The mRNA and soluble protein levels of αA-crystallin and αB-crystallin in the human lens epithelium were detected by real-time PCR and western blots, respectively. The mRNA and soluble protein expressions of αA-crystallin and αB-crystallin in the lens epithelium were both reduced in age-related and congenital cataract groups when compared with the normal control group. However, the degree of α-crystallin loss in the lens epithelium was highly correlated with different cataract types. The α-crystallin expression of the lens epithelium was greatly reduced in the congenital cataract group but only moderately decreased in the age-related cataract group. The reduction of αA-crystallin soluble protein levels in the congenital cataract group was approximately 2.4 fold decrease compared with that of the age-related cataract group, while an mRNA fold change of 1.67 decrease was observed for the age-related cataract group. Similarly, the reduction of soluble protein levels of αB-crystallin in the congenital cataract group was approximately a 1.57 fold change compared with that of the age-related cataract group. A 1.75 fold change for mRNA levels compared with that of the age-related cataract group was observed. The results suggest that the differential loss of α-crystallin in the human lens epithelium could be associated with the different mechanisms of cataractogenesis in age-related versus congenital cataracts, subsequently resulting in different clinical presentations.

  2. The Associations of Lens Power With Age and Axial Length in Healthy Chinese Children and Adolescents Aged 6 to 18 Years.

    Science.gov (United States)

    Xiong, Shuyu; Zhang, Bo; Hong, Yuan; He, Xiangui; Zhu, Jianfeng; Zou, Haidong; Xu, Xun

    2017-11-01

    To investigate the relationship between lens power and age as well as the relationship between lens power and axial length (AL) in Chinese children and adolescents. The participants underwent a comprehensive ophthalmic examination that included AL, cycloplegic refraction, and Pentacam measurements. The crystalline lens power was calculated using Bennett's formula and then compared among the children of different age groups, refractive statuses, and AL categories. The association of lens power and AL was analyzed using multiple regression. A total of 1992 children and adolescents aged 6- to 18-years old were included. The difference in lens power was greater before 10-years old, followed by a relatively smaller difference in children aged 10 to 14 years and the difference in lens power came to a near plateau in adolescents after 14-years old. The negative association between lens power and AL was found to be more evident in nonmyopes than in myopes irrespective of age (younger than 10 years: nonmyopes: β = -1.499, myopes: β = -0.872; older than 10 years: nonmyopes: β = -1.288, myopes: β = -0.390, all P power in children and adolescents aged 6 to 18 years exhibited three stages. The association between lens power and AL differed between the nonmyopes and myopes. These findings suggested that less reduction in lens power might be associated with both growing age and increasing AL in myopes.

  3. Shakespeare through the Lens of a New Age.

    Science.gov (United States)

    Tabers-Kwak, Linda; Kaufman, Timothy U.

    2002-01-01

    Discusses two approaches that engage both students and teachers as they come to share an understanding of Shakespeare's relevance to all ages. Suggests teaching Shakespeare through picture books and through music. Notes that one of the first ways to modernize Shakespeare is to allow students to interact with the work. (SG)

  4. Age-related changes in functional postsynaptic nAChR subunits in neurons of the laterodorsal tegmental nucleus, a nucleus important in drug addiction

    DEFF Research Database (Denmark)

    Christensen, Mark Holm; Kohlmeier, Kristi Anne

    2016-01-01

    the laterodorsal tegmentum (LDT), a nucleus importantly involved in drug addiction associated behaviours, across two periods of ontogeny in which nicotine-mediated excitatory responses were shown to depend on age. To this end, whole-cell patch-clamp recordings in mouse brain slices from identified LDT neurons...

  5. Metabolism of Dopamine in Nucleus Accumbens Astrocytes Is Preserved in Aged Mice Exposed to MPTP

    Directory of Open Access Journals (Sweden)

    Brittany M. Winner

    2017-12-01

    Full Text Available Parkinson disease (PD is prevalent in elderly individuals and is characterized by selective degeneration of nigrostriatal dopamine (NSDA neurons. Interestingly, not all dopamine (DA neurons are affected equally by PD and aging, particularly mesolimbic (ML DA neurons. Here, effects of aging were examined on presynaptic DA synthesis, reuptake, metabolism and neurotoxicant susceptibility of NSDA and mesolimbic dopamine (MLDA neurons and astrocyte DA metabolism. There were no differences in phenotypic markers of DA synthesis, reuptake or metabolism in NSDA or MLDA neurons in aged mice, but MLDA neurons displayed lower DA stores. Astrocyte metabolism of DA to 3-methoxytyramine (3-MT in the striatum was decreased in aged mice, but was maintained in the nucleus accumbens. Despite diminished DA vesicular storage capacity in MLDA neurons, susceptibility to acute neurotoxicant exposure was similar in young and aged mice. These results reveal an age- and neurotoxicant-induced impairment of DA metabolic activity in astrocytes surrounding susceptible NSDA neurons as opposed to maintenance of DA metabolism in astrocytes surrounding resistant MLDA neurons, and suggest a possible therapeutic target for PD.

  6. Effect of miR-138 on the antioxidant function of lens epithelial cells affected by age-related cataracts

    Directory of Open Access Journals (Sweden)

    Bo Lu

    2018-03-01

    Full Text Available AIM: To investigate the effects and mechanism of miR-138 in mediating the antioxidant function of lens epithelial cells affected by age-related cataracts. METHODS: Real-time quantitative PCR(RT-qPCRwas used to detect miR-138 expression in the anterior lens capsules of healthy people, the anterior lens capsules of patients with age-related cataracts, and human epithelial cell line(SRA01/04cells exposed to oxidative stress. A 2', 7'-dichloro-fluorescein diacetate(DCFH-DAprobe was used to measure the levels of endogenous reactive oxygen species(ROSin human lens epithelial cells(hLECsexposed to 400μmol/L H2O2 for 1h. SRA01/04 cells were transfected with either miR-138 mimics, mimic controls, miR-138 inhibitors or inhibitor controls. After 72h, these cells were exposed to 400μmol/L H2O2 for 1h, then p53 and Bax mRNA expression were measured using RT-qPCR. Expression of p53 and Bax protein were also measured by western blotting analysis. Finally, cell viability was assessed using an MTS assay. RESULTS: Compared to the control group, expression of miR-138 in the anterior lens capsules of age-related cataract patients and in SRA01/04 cells exposed to oxidative stress significantly increased(PPPPCONCLUSION: The expression of miR-138 is upregulated in the anterior lens capsules of age-related cataract patients. MiR-138 decreases the anti-oxidative stress capacity of lens epithelial cells by upregulating p53 and Bax, while inhibiting cell proliferation and repair. This finding suggests that miR-138 may play a key role in the development of age-related cataracts.

  7. Age-related compaction of lens fibers affects the structure and optical properties of rabbit lenses

    Directory of Open Access Journals (Sweden)

    Al-Ghoul Walid M

    2007-12-01

    Full Text Available Abstract Background The goal of this investigation was to correlate particular age-related structural changes (compaction to the amount of scatter in rabbit lenses and to determine if significant fiber compaction occurred in the nuclear and inner cortical regions. Methods New Zealand White rabbits at 16–20 months old (adult; n = 10 and at 3.5–4 years old (aged; n = 10 were utilized for this study. Immediately after euthanising, scatter was assessed in fresh lenses by low power helium-neon laser scan analysis. Scatter data was analyzed both for whole lenses and regionally, to facilitate correlation with morphometric data. After functional analysis, lenses were fixed and processed for scanning electron microcopy (SEM; right eyes and light microscopy (LM; left eyes. Morphometric analysis of SEM images was utilized to evaluate compaction of nuclear fibers. Similarly, measurements from LM images were used to assess compaction of inner cortical fibers. Results Scatter was significantly greater in aged lenses as compared to adult lenses in all regions analyzed, however the difference in the mean was slightly more pronounced in the inner cortical region. The anterior and posterior elliptical angles at 1 mm (inner fetal nucleus were significantly decreased in aged vs. adult lenses (anterior, p = 0.040; posterior, p = 0.036. However, the average elliptical angles at 2.5 mm (outer fetal nucleus were not significantly different in adult and aged lenses since all lenses examined had comparable angles to inner fetal fibers of aged lenses, i.e. they were all compacted. In cortical fibers, measures of average cross-sectional fiber area were significantly different at diameters of both 6 and 7 mm as a function of age (p = 0.011 and p = 0.005, respectively. Accordingly, the estimated fiber volume was significantly decreased in aged as compared to adult lenses at both 6 mm diameter (p = 0.016 and 7 mm diameter (p = 0.010. Conclusion Morphometric data indicates

  8. Monoamine levels in the nucleus accumbens correlate with male sexual behavior in middle-aged rats.

    Science.gov (United States)

    Tsai, Houng-Wei; Shui, Hao-Ai; Liu, Hang-Shen; Tai, Mei-Yun; Tsai, Yuan-Feen

    2006-02-01

    The correlation between monoamine levels in the nucleus accumbens (NAcc) and male sexual behavior was studied in middle-aged rats. Male rats (18-19months) were assigned to three groups: (1) Group MIE consisted of rats showing mounts, intromissions, and ejaculations; (2) Group MI was composed of rats showing mounts and intromissions, but no ejaculation; and (3) Group NC were non-copulators showing no sexual behavior. Young adult rats (4-5months), displaying complete copulatory behavior, were used as the control group. Levels of dopamine (DA), serotonin, and norepinephrine and their metabolites in the NAcc were measured by high-pressure liquid chromatography with electrochemical detection. No difference was seen in DA levels between MIE rats and young controls, whereas DA levels in NC rats were significantly lower than those in both MIE and MI rats. Serotonin levels in NC rats were significantly higher than those in MIE and MI rats. Conversely, norepinephrine levels in NC rats were lower than those in MIE rats. These results suggest that monoamine levels in the NAcc correlate with sexual performance in male rats and that changes in NAcc monoamine levels might affect male sexual behavior in middle-aged rats.

  9. Endogenous leptin contributes to baroreflex suppression within the solitary tract nucleus of aged rats

    Science.gov (United States)

    Arnold, Amy C.

    2014-01-01

    The decline in cardiovagal baroreflex function that occurs with aging is accompanied by an increase in circulating leptin levels. Our previous studies showed that exogenous leptin impairs the baroreflex sensitivity for control of heart rate in younger rats, but the contribution of this hormone to baroreflex dysfunction during aging is unknown. Thus we assessed the effect of bilateral leptin microinjection (500 fmol/60 nl) within the solitary tract nucleus (NTS) on the baroreflex sensitivity in older (66 ± 2 wk of age) urethane/chloralose anesthetized Sprague-Dawley rats with elevated circulating leptin levels. In contrast to the 63% reduction observed in younger rats, leptin did not alter the baroreflex sensitivity for bradycardia evoked by phenylephrine in older rats (0.76 ± 0.19 baseline vs. 0.71 ± 0.15 ms/mmHg after leptin; P = 0.806). We hypothesized that this loss of sensitivity reflected endogenous suppression of the baroreflex by elevated leptin, rather than cardiovascular resistance to the peptide. Indeed, NTS administration of a leptin receptor antagonist (75 pmol/120 nl) improved the baroreflex sensitivity for bradycardia in older rats (0.73 ± 0.13 baseline vs. 1.19 ± 0.26 at 10 min vs. 1.87 ± 0.32 at 60 min vs. 1.22 ± 0.54 ms/mmHg at 120 min; P = 0.002), with no effect in younger rats. There was no effect of the leptin antagonist on the baroreflex sensitivity for tachycardia, responses to cardiac vagal chemosensitive fiber activation, or resting hemodynamics in older rats. These findings suggest that the actions of endogenous leptin within the NTS, either produced locally or derived from the circulation, contribute to baroreflex suppression during aging. PMID:25260611

  10. A dimensionless ordered pull-through model of the mammalian lens epithelium evidences scaling across species and explains the age-dependent changes in cell density in the human lens

    Science.gov (United States)

    Wu, Jun Jie; Wu, Weiju; Tholozan, Frederique M.; Saunter, Christopher D.; Girkin, John M.; Quinlan, Roy A.

    2015-01-01

    We present a mathematical (ordered pull-through; OPT) model of the cell-density profile for the mammalian lens epithelium together with new experimental data. The model is based upon dimensionless parameters, an important criterion for inter-species comparisons where lens sizes can vary greatly (e.g. bovine (approx. 18 mm); mouse (approx. 2 mm)) and confirms that mammalian lenses scale with size. The validated model includes two parameters: β/α, which is the ratio of the proliferation rate in the peripheral and in the central region of the lens; and γGZ, a dimensionless pull-through parameter that accounts for the cell transition and exit from the epithelium into the lens body. Best-fit values were determined for mouse, rat, rabbit, bovine and human lens epithelia. The OPT model accounts for the peak in cell density at the periphery of the lens epithelium, a region where cell proliferation is concentrated and reaches a maximum coincident with the germinative zone. The β/α ratio correlates with the measured FGF-2 gradient, a morphogen critical to lens cell survival, proliferation and differentiation. As proliferation declines with age, the OPT model predicted age-dependent changes in cell-density profiles, which we observed in mouse and human lenses. PMID:26236824

  11. Age-related changes in functional postsynaptic nicotinic acetylcholine receptor subunits in neurons of the laterodorsal tegmental nucleus, a nucleus important in drug addiction.

    Science.gov (United States)

    Christensen, Mark H; Kohlmeier, Kristi A

    2016-03-01

    The earlier an individual initiates cigarette smoking, the higher the likelihood of development of dependency to nicotine, the addictive ingredient in cigarettes. One possible mechanism underlying this higher addiction liability is an ontogenetically differential cellular response induced by nicotine in neurons mediating the reinforcing or euphoric effects of this drug, which could arise from age-related differences in the composition of nicotinic acetylcholine receptor (nAChR) subunits. In the current study, we examined whether the subunit composition of nAChRs differed between neurons within the laterodorsal tegmentum (LDT), a nucleus importantly involved in drug addiction associated behaviours, across two periods of ontogeny in which nicotine-mediated excitatory responses were shown to depend on age. To this end, whole-cell patch-clamp recordings in mouse brain slices from identified LDT neurons, in combination with nAChR subunit-specific receptor antagonists, were conducted. Comparison of the contribution of different nAChR subunits to acetylcholine (ACh)-induced inward currents indicated that the contributions of the β2 and/or β4 and α7 nAChR subunits alter across age. Taken together, we conclude that across a limited ontogenetic period, there is plasticity in the subunit composition of nAChRs in LDT neurons. In addition, our data indicate, for the first time, functional presence of α6 nAChR subunits in LDT neurons within the age ranges studied. Changes in subunit composition of nAChRs across ontogeny could contribute to the age-related differential excitability induced by nicotine. Differences in the subunit composition of nAChRs within the LDT would be expected to contribute to ontogenetic-dependent outflow from the LDT to target regions, which include reward-related circuitry. © 2014 Society for the Study of Addiction.

  12. Activity of vasopressinergic neurones of the human supraoptic nucleus is age- and sex-dependent

    NARCIS (Netherlands)

    Ishunina, T. A.; Salehi, A.; Hofman, M. A.; Swaab, D. F.

    1999-01-01

    In the human hypothalamus, arginine-vasopressin (AVP) is produced for a major part by the neurones of the supraoptic nucleus (SON). Since plasma AVP levels in men were reported to be higher than those of women and we did not find a sex difference in the neurone number, a higher vasopressinergic

  13. Quantitative Analysis of Lens Nuclear Density Using Optical Coherence Tomography (OCT with a Liquid Optics Interface: Correlation between OCT Images and LOCS III Grading

    Directory of Open Access Journals (Sweden)

    You Na Kim

    2016-01-01

    Full Text Available Purpose. To quantify whole lens and nuclear lens densities using anterior-segment optical coherence tomography (OCT with a liquid optics interface and evaluate their correlation with Lens Opacities Classification System III (LOCS III lens grading and corrected distance visual acuity (BCVA. Methods. OCT images of the whole lens and lens nucleus of eyes with age-related nuclear cataract were analyzed using ImageJ software. The lens grade and nuclear density were represented in pixel intensity units (PIU and correlations between PIU, BCVA, and LOCS III were assessed. Results. Forty-seven eyes were analyzed. The mean whole lens and lens nuclear densities were 26.99 ± 5.23 and 19.43 ± 6.15 PIU, respectively. A positive linear correlation was observed between lens opacities (R2 = 0.187, p<0.01 and nuclear density (R2 = 0.316, p<0.01 obtained from OCT images and LOCS III. Preoperative BCVA and LOCS III were also positively correlated (R2 = 0.454, p<0.01. Conclusions. Whole lens and lens nuclear densities obtained from OCT correlated with LOCS III. Nuclear density showed a higher positive correlation with LOCS III than whole lens density. OCT with a liquid optics interface is a potential quantitative method for lens grading and can aid in monitoring and managing age-related cataracts.

  14. Deconfinement of quarks and gluons in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Gorenstein, M.I.

    2011-01-01

    The energy dependence of hadron production in relativistic nucleus-nucleus collisions reveals the anomalies. They were predicted as the signals of the deconfinement phase transition and observed by NA49 collaboration in Pb+Pb collisions at the CERN SPS. This indicates the onset of the deconfinement in central nucleus-nucleus collisions at about 30 AGeV.

  15. The lens and cataracts.

    Science.gov (United States)

    Matthews, Andrew G

    2004-08-01

    It is conservatively estimated that some form of lens opacity is present in 5% to 7% of horses with otherwise clinically normal eyes.These opacities can range from small epicapsular remnants of the fetal vasculature to dense and extensive cataract. A cataract is defined technically as any opacity or alteration in the optical homogeneity of the lens involving one or more of the following: anterior epithelium, capsule, cortex, or nucleus. In the horse, cataracts rarely involve the entire lens structure (ie, complete cataracts) and are more usually localized to one anatomic landmark or sector of the lens. Complete cataracts are invariably associated with overt and significant visual disability. Focal or incomplete cataracts alone seldom cause any apparent visual dysfunction in affected horses,however.

  16. Further studies of the effects of aging on arginine metabolites in the rat vestibular nucleus and cerebellum.

    Science.gov (United States)

    Liu, P; Gupta, N; Jing, Y; Collie, N D; Zhang, H; Smith, P F

    2017-04-21

    Some studies have demonstrated that aging is associated with impaired vestibular reflexes, especially otolithic reflexes, resulting in postural instability. However, the neurochemical basis of these age-related changes is still poorly understood. The l-arginine metabolic system has been implicated in changes in the brain associated with aging. In the current study, we examined the levels of l-arginine and its metabolizing enzymes and downstream metabolites in the vestibular nucleus complex (VNC) and cerebellum (CE) of rats with and without behavioral testing which were young (4months old), middle-aged (12months old) or aged (24months old). We found that aging was associated with lower nitric oxide synthase activity in the CE of animals with testing and increased arginase in the VNC and CE of animals with testing. l-citrulline and l-ornithine were lower in the VNC of aged animals irrespective of testing, while l-arginine and l-citrulline were lower in the CE with and without testing, respectively. In the VNC and CE, aging was associated with lower levels of glutamate in the VNC, irrespective of testing. In the VNC it was associated with higher levels of agmatine and putrescine, irrespective of testing. In the CE, aging was associated with higher levels of putrescine in animals without testing and with higher levels of spermine in animals with testing, and spermidine, irrespective of testing. Multivariate analyses indicated significant predictive relationships between the different variables, and there were correlations between some of the neurochemical variables and behavioral measurements. Cluster analyses revealed that aging altered the relationships between l-arginine and its metabolites. The results of this study demonstrate that there are major changes occurring in l-arginine metabolism in the VNC and CE as a result of age, as well as behavioral activity. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  17. Nature of multiplicity correlations in 12C-nucleus reaction at 4.5 AGeV

    International Nuclear Information System (INIS)

    Saleem Khan, M.; Shukla, Praveen Prakash; Khushnood, H.

    2011-01-01

    Multiplicity correlations in high energy hadron-nucleus and nucleus-nucleus interactions are considered one of the most important parameter to study the dynamics of particles production. In the present work, an attempt has been made to understand the nature of the multiplicity correlations

  18. Effects of age, replicative lifespan and growth rate of human nucleus pulposus cells on selecting age range for cell-based biological therapies for degenerative disc diseases.

    Science.gov (United States)

    Lee, J S; Lee, S M; Jeong, S W; Sung, Y G; Lee, J H; Kim, K W

    2016-07-01

    Autologous disc cell implantation, growth factors and gene therapy appear to be promising therapies for disc regeneration. Unfortunately, the replicative lifespan and growth kinetics of human nucleus pulposus (NP) cells related to host age are unclear. We investigated the potential relations among age, replicative lifespan and growth rate of NP cells, and determined the age range that is suitable for cell-based biological therapies for degenerative disc diseases. We used NP tissues classified by decade into five age groups: 30s, 40s, 50s, 60s and 70s. The mean cumulative population doubling level (PDL) and population doubling rate (PDR) of NP cells were assessed by decade. We also investigated correlations between cumulative PDL and age, and between PDR and age. The mean cumulative PDL and PDR decreased significantly in patients in their 60s. The mean cumulative PDL and PDR in the younger groups (30s, 40s and 50s) were significantly higher than those in the older groups (60s and 70s). There also were significant negative correlations between cumulative PDL and age, and between PDR and age. We found that the replicative lifespan and growth rate of human NP cells decreased with age. The replicative potential of NP cells decreased significantly in patients 60 years old and older. Young individuals less than 60 years old may be suitable candidates for NP cell-based biological therapies for treating degenerative disc diseases.

  19. Nucleus--nucleus potential

    International Nuclear Information System (INIS)

    Jaqaman, H.R.

    1977-01-01

    The nucleus--nucleus interaction is studied within the framework of the generator coordinate method that permits an easy incorporation of the full effects of antisymmetrization. It is found that the interaction, as far as the elastic scattering problem is concerned, can be described by a simple effective potential that is equivalent to the original many-body (and hence non-local) problem. The potential is obtained by dividing the wavefunction into a long-range part and a short-range part and requiring the former to satisfy a Schroedinger equation. This enables avoiding dealing with the troublesome short-range part of the wavefunction and provides a direct link with the optical model so that the potential obtained here is equivalent to the real part of the optical potential (the imaginary part is not investigated). The effective potential is found to consist of three parts: an interaction term between the nucleons belonging to different nuclei, a kinetic energy term due to the change in the intrinsic kinetic energy of the system as a result of the antisymmetrization, and finally an l-dependent part. The kinetic energy term is found to be very repulsive and effectively gives a hard core, and is calculated for the α--α and 16 O-- 16 O cases. The full potential is calculated for the α--α case for the S, D, and G partial waves and then used to calculate the corresponding phase shifts that are then compared with experimental results and other microscopic calculations. Finally, some recent results and analyses of fusion and deep inelastic reactions are reviewed that seem to indicate the presence of a hard core in the nucleus--nucleus potential. Such a hard core is present in the potential obtained in the sudden approximation

  20. Metabolism of Dopamine in Nucleus Accumbens Astrocytes Is Preserved in Aged Mice Exposed to MPTP

    OpenAIRE

    Brittany M. Winner; Brittany M. Winner; Harue Zhang; McKenzie M. Farthing; Lalitha M. Karchalla; Keith J. Lookingland; Keith J. Lookingland; Keith J. Lookingland; John L. Goudreau; John L. Goudreau; John L. Goudreau; John L. Goudreau

    2017-01-01

    Parkinson disease (PD) is prevalent in elderly individuals and is characterized by selective degeneration of nigrostriatal dopamine (NSDA) neurons. Interestingly, not all dopamine (DA) neurons are affected equally by PD and aging, particularly mesolimbic (ML) DA neurons. Here, effects of aging were examined on presynaptic DA synthesis, reuptake, metabolism and neurotoxicant susceptibility of NSDA and mesolimbic dopamine (MLDA) neurons and astrocyte DA metabolism. There were no differences in ...

  1. Metabolism of Dopamine in Nucleus Accumbens Astrocytes Is Preserved in Aged Mice Exposed to MPTP

    OpenAIRE

    Winner, Brittany M.; Zhang, Harue; Farthing, McKenzie M.; Karchalla, Lalitha M.; Lookingland, Keith J.; Goudreau, John L.

    2017-01-01

    Parkinson disease (PD) is prevalent in elderly individuals and is characterized by selective degeneration of n igro s triatal d op a mine (NSDA) neurons. Interestingly, not all dopamine (DA) neurons are affected equally by PD and aging, particularly m eso l imbic (ML) DA neurons. Here, effects of aging were examined on presynaptic DA synthesis, reuptake, metabolism and neurotoxicant susceptibility of NSDA and mesolimbic dopamine (MLDA) neurons and astrocyte DA metabolism. There were no differ...

  2. Effects of seed size and aging on field performance of lentil (Lens culinaris Medik. under different irrigation treatments

    Directory of Open Access Journals (Sweden)

    Kazem GHASSEMI-GOLEZANI

    2015-12-01

    Full Text Available A sub-sample of lentil (Lens culinaris ‘Kimia’ seeds was kept as bulk (S1 and another sample was separated to large (S2 and small (S3 seeds. A sub-sample of each size was kept as control or high vigor seed lot (A1 and the two other sub-samples were artificially aged for 2 and 4 days (A2 and A3, respectively. Field performance of these seeds was evaluated during 2011 and 2012. Yield components and grain yield of lentil decreased with decreasing water availability. The highest yield components (except 1000 grain weight and grain yield per unit area were obtained by plants from large seeds. The superiority of plants from large seeds in grain yield was more evident under limited irrigations than under well watering. Seed aging resulted in poor stand establishment and consequently low grain yield per unit area. Plants from aged large seeds showed the lowest reduction in grain yield per unit area, compared with those from aged small and bulk seeds. It seems that cultivation of large seeds somehow can reduce the deleterious effects of drought stress and seed aging on grain yield per unit area of lentil.

  3. [The effect of yellow filter intraocular lens on the macula after cataract phacoemulsification in patients with age macular degeneration].

    Science.gov (United States)

    Shpak, A A; Maliugin, B É; Fadeeva, T V

    2012-01-01

    Macula changes diagnosed with optical coherence tomography (OCT) within a year after cataract phacoemulsification (PE) with intraocular lens implantation with and without yellow filter are presented. 32 patients (36 eyes) with early stages of age macular degeneration (AMD) were included into the experimental group and 35 patients (36 eyes) served as controls. IOLs with yellow filter were implanted in 21 eyes, and in 15 cases IOLs without filter were used in each group. According to OCT data thickening of fovea and increasing of macula volume developed within 6 months after cataract PE. Implantation of yellow filter IOLs reduced the intensity of these changes after surgery in patients with AMD. The progression of early AMD into advanced stages within a year after PE was not observed.

  4. Secondhand tobacco smoke exposure differentially alters nucleus tractus solitarius neurons at two different ages in developing non-human primates

    International Nuclear Information System (INIS)

    Sekizawa, Shin-ichi; Joad, Jesse P.; Pinkerton, Kent E.; Bonham, Ann C.

    2010-01-01

    Exposing children to secondhand tobacco smoke (SHS) is associated with increased risk for asthma, bronchiolitis and SIDS. The role for changes in the developing CNS contributing to these problems has not been fully explored. We used rhesus macaques to test the hypothesis that SHS exposure during development triggers neuroplastic changes in the nucleus tractus solitarius (NTS), where lung sensory information related to changes in airway and lung function is first integrated. Pregnant monkeys were exposed to filtered air (FA) or SHS for 6 h/day, 5 days/week starting at 50-day gestational age. Mother/infant pairs continued the exposures postnatally to age 3 or 13 months, which may be equivalent to approximately 1 or 4 years of human age, respectively. Whole-cell recordings were made of second-order NTS neurons in transverse brainstem slices. To target the consequences of SHS exposure based on neuronal subgroups, we classified NTS neurons into two phenotypes, rapid-onset spiking (RS) and delayed-onset spiking (DS), and then evaluated intrinsic and synaptic excitabilities in FA-exposed animals. RS neurons showed greater cell excitability especially at age of 3 months while DS neurons received greater amplitudes of excitatory postsynaptic currents (EPSCs). Developmental neuroplasticity such as increases in intrinsic and synaptic excitabilities were detected especially in DS neurons. In 3 month olds, SHS exposure effects were limited to excitatory changes in RS neurons, specifically increases in evoked EPSC amplitudes and increased spiking responses accompanied by shortened action potential width. By 13 months, the continued SHS exposure inhibited DS neuronal activity; decreases in evoked EPSC amplitudes and blunted spiking responses accompanied by prolonged action potential width. The influence of SHS exposure on age-related and phenotype specific changes may be associated with age-specific respiratory problems, for which SHS exposure can increase the risk, such as SIDS

  5. Effects of Repeated Stress on Age-Dependent GABAergic Regulation of the Lateral Nucleus of the Amygdala.

    Science.gov (United States)

    Zhang, Wei; Rosenkranz, J Amiel

    2016-08-01

    The adolescent age is associated with lability of mood and emotion. The onset of depression and anxiety disorders peaks during adolescence and there are differences in symptomology during adolescence. This points to differences in the adolescent neural circuitry that underlies mood and emotion, such as the amygdala. The human adolescent amygdala is more responsive to evocative stimuli, hinting to less local inhibitory regulation of the amygdala, but this has not been explored in adolescents. The amygdala, including the lateral nucleus (LAT) of the basolateral amygdala complex, is sensitive to stress. The amygdala undergoes maturational processes during adolescence, and therefore may be more vulnerable to harmful effects of stress during this time period. However, little is known about the effects of stress on the LAT during adolescence. GABAergic inhibition is a key regulator of LAT activity. Therefore, the purpose of this study was to test whether there are differences in the local GABAergic regulation of the rat adolescent LAT, and differences in its sensitivity to repeated stress. We found that LAT projection neurons are subjected to weaker GABAergic inhibition during adolescence. Repeated stress reduced in vivo endogenous and exogenous GABAergic inhibition of LAT projection neurons in adolescent rats. Furthermore, repeated stress decreased measures of presynaptic GABA function and interneuron activity in adolescent rats. In contrast, repeated stress enhanced glutamatergic drive of LAT projection neurons in adult rats. These results demonstrate age differences in GABAergic regulation of the LAT, and age differences in the mechanism for the effects of repeated stress on LAT neuron activity. These findings provide a substrate for increased mood lability in adolescents, and provide a substrate by which adolescent repeated stress can induce distinct behavioral outcomes and psychiatric symptoms.

  6. Altered DNA Methylation and Expression Profiles of 8-Oxoguanine DNA Glycosylase 1 in Lens Tissue from Age-related Cataract Patients.

    Science.gov (United States)

    Wang, Yong; Li, Fei; Zhang, Guowei; Kang, Lihua; Qin, Bai; Guan, Huaijin

    2015-01-01

    Oxidative stress and DNA damage contribute to the pathogenesis of age-related cataract (ARC). Most oxidative DNA lesions are repaired via the base excision repair (BER) proteins including 8-oxoguanine DNA glycosylase 1 (OGG1). This study examined DNA methylation of CpG islands upstream of OGG1 and their relation to the gene expression in lens cortex from ARC patients. The clinical case-control study consisted of 15 cortical type of ARC patients and 15 age-matched non-ARC controls who received transparent lens extraction due to vitreoretinal diseases. OGG1 expression in lens cortex was analyzed by qRT-PCR and Western blot. The localization and the proportion of cells positive for OGG1 were determined by immunofluorescence. Bisulfite-sequencing PCR (BSP) was performed to evaluate the methylation status of CpG islands near OGG1 in DNA extracted from lens cortex. To test relationship between the methylation and the expression of the gene of interest, 5-Aza-2'-deoxycytidine (5-Aza-dC) was used to induce demethylation of cultured human lens epithelium B-3 (HLE B-3). To test the role of OGG1 in the repair of cellular damage, HLE B-3 was transfected with OGG1 vector, followed by ultraviolet radiation b (UVB) exposure to induce apoptosis. The mRNA and protein levels of OGG1 were significantly reduced in the lens cortex of ARC. Immunofluorescence showed that the proportion of OGG1-positive cells decreased significantly in ARC cortex in comparison with the control. The CpG island in first exon of OGG1 displayed hypermethylation in the DNA extracted from the lens cortex of ARC. Treatment of HLEB-3 cells with 5-Aza-dC upregulated OGG1 expression. UVB-induced apoptosis was attenuated after transfection with OGG1. A reduced OGG1 expression was correlated with hypermethylation of a CpG island of OGG1 in lens cortex of ARC. The role of epigenetic change in OGG1 gene in the susceptibility to oxidative stress induced cortical ARC is warranted to further study.

  7. Male sexual behavior and catecholamine levels in the medial preoptic area and arcuate nucleus in middle-aged rats.

    Science.gov (United States)

    Chen, Joyce C; Tsai, Houng-Wei; Yeh, Kuei-Ying; Tai, Mei-Yun; Tsai, Yuan-Feen

    2007-12-12

    The correlation between male sexual behavior and catecholamine levels in the medial preoptic area (MPOA) and arcuate nucleus (ARN) was studied in middle-aged rats. Male rats (18-19 months) were assigned to three groups: (1) Group MIE, consisting of rats showing mounts, intromissions, and ejaculations; (2) Group MI, consisting of rats showing mounts and intromissions, but no ejaculation; and (3) Group NC, consisting of non-copulators showing no sexual behavior. Young adult rats (4-5 months) displaying complete copulatory behavior were used as the control group. Dopamine (DA) and norepinephrine (NE) tissue levels in the MPOA and ARN were measured by high pressure liquid chromatography with electrochemical detection. There were no differences between MIE rats and young controls in DA or NE tissue levels in these two brain areas. Furthermore, no differences were found between the MI and NC groups in DA or NE tissue levels in either the MPOA or ARN. DA tissue levels in the MPOA and ARN in the MI and NC groups were significantly lower than those in the MIE group. NE tissue levels in the MPOA of the NC group were significantly lower than those in the MIE group, but no differences in NE tissue levels in the ARN were seen between the four groups. These results suggest that, in male rats, complete male sexual performance is related to tissue levels of DA, but not of NE, in the MPOA and/or ARN. Furthermore, ejaculatory behavior might be associated with critical DA tissue levels in the MPOA and/or ARN in middle-aged rats.

  8. Selective deletion of cochlear hair cells causes rapid age-dependent changes in spiral ganglion and cochlear nucleus neurons.

    Science.gov (United States)

    Tong, Ling; Strong, Melissa K; Kaur, Tejbeer; Juiz, Jose M; Oesterle, Elizabeth C; Hume, Clifford; Warchol, Mark E; Palmiter, Richard D; Rubel, Edwin W

    2015-05-20

    During nervous system development, critical periods are usually defined as early periods during which manipulations dramatically change neuronal structure or function, whereas the same manipulations in mature animals have little or no effect on the same property. Neurons in the ventral cochlear nucleus (CN) are dependent on excitatory afferent input for survival during a critical period of development. Cochlear removal in young mammals and birds results in rapid death of target neurons in the CN. Cochlear removal in older animals results in little or no neuron death. However, the extent to which hair-cell-specific afferent activity prevents neuronal death in the neonatal brain is unknown. We further explore this phenomenon using a new mouse model that allows temporal control of cochlear hair cell deletion. Hair cells express the human diphtheria toxin (DT) receptor behind the Pou4f3 promoter. Injections of DT resulted in nearly complete loss of organ of Corti hair cells within 1 week of injection regardless of the age of injection. Injection of DT did not influence surrounding supporting cells directly in the sensory epithelium or spiral ganglion neurons (SGNs). Loss of hair cells in neonates resulted in rapid and profound neuronal loss in the ventral CN, but not when hair cells were eliminated at a more mature age. In addition, normal survival of SGNs was dependent on hair cell integrity early in development and less so in mature animals. This defines a previously undocumented critical period for SGN survival. Copyright © 2015 the authors 0270-6474/15/357878-14$15.00/0.

  9. Analysis of the post-translational modifications of the individual amino acids in lens proteins which were induced by aging and irradiation

    International Nuclear Information System (INIS)

    Fujii, Noriko; Kim, Ingu; Saito, Takeshi; Takata, Takumi

    2017-01-01

    The eye lens is a transparent organ that functions to focus light and images on the retina. The transparency and high refraction of the lens are maintained by the function of α-, β- and γ-crystallins. These long-lived proteins are subject to various post-translational modifications, such as oxidation, deamidation, truncation and isomerization, which occur gradually during the aging process. Such modifications, which are generated by UV light and oxidative stress, decrease crystallin solubility and lens transparency, and ultimately lead to the development of age-related cataracts. Here, we irradiated young rat lenses with γ-rays (5-500 Gy) and extracted the water-soluble (WS) and insoluble (WI) protein fractions. The WS and WI lens proteins were digested with trypsin, and the resulting peptides were analyzed by one-shot LC-MS/MS to determine the specific sites of oxidation of methionine and tryptophan, deamidation of asparagine and glutamine, and isomerization of aspartyl in rat α- and β-crystallins in the WS and WI fractions. Oxidation and deamidation occurred in several crystallins after irradiation at more than, respectively, 50 Gy and 5 Gy; however, isomerization did not occur in any crystallin even after exposure to 500 Gy of irradiation. The number of oxidation and deamidation sites was much higher in the WI than in the WS fraction. Furthermore, the oxidation and deamidation sites in rat crystallins resemble those reported in crystallins from human age-related cataracts. Thus, this study on post-translational modifications of crystallins induced by ionizing irradiation may provide useful information relevant to the formation of human age-related cataracts. (author)

  10. Ring and jet-like structures and two-dimensional intermittency in nucleus-nucleus collisions at 200 AGeV/c

    International Nuclear Information System (INIS)

    Ghosh, M.K.; Haldar, P.K.; Manna, S.K.; Mukhopadhyay, A.; Singh, G.

    2011-01-01

    We have investigated the presence of ring and/or jet-like structures in the angular emission of secondary charged mesons (shower tracks) coming out of 16 O-Ag/Br and 32 S-Ag/Br interactions, each at an incident momentum of 200 AGeV/c. Nuclear photographic emulsion technique has been used to collect the experimental data. The experimental results have been compared with the results simulated by Monte Carlo method. The analysis indicates presence of ring and jet-like structures in the experimental data beyond statistical noise. This kind of jet structure is expected to give rise to a strong two-dimensional (2d) intermittency. The self-affine behaviour of 2d scaled factorial moments (SFM) has therefore been investigated and the strength of 2d intermittency has been determined. For each set of data the 2d results have been compared with the respective one-dimensional (1d) intermittency results.

  11. Somatostatin-immunoreactive senile plaque-like structures in the frontal cortex and nucleus accumbens of aged tree shrews and Japanese macaques.

    Science.gov (United States)

    Yamashita, Akiko; Fuchs, Eberhard; Taira, Masato; Yamamoto, Takamitsu; Hayashi, Motoharu

    2012-06-01

    Previously, we demonstrated decreased expression of somatostatin mRNA in aged macaque brain, particularly in the prefrontal cortex. To investigate whether or not this age-dependent decrease in mRNA is related to morphological changes, we analyzed somatostatin cells in the cerebra of aged Japanese macaques and compared them with those in rats and tree shrews, the latter of which are closely related to primates. Brains of aged macaques, tree shrews, and rats were investigated by immunohistochemistry with special emphasis on somatostatin. We observed degenerating somatostatin-immunoreactive cells in the cortices of aged macaques and tree shrews. Somatostatin-immunoreactive senile plaque-like structures were found in areas 6 and 8 and in the nucleus accumbens of macaques, as well as in the nucleus accumbens and the cortex of aged tree shrews, where amyloid accumulations were observed. Somatostatin degenerations may be related to amyloid accumulations and may play roles in impairments of cognitive functions during aging. © 2012 John Wiley & Sons A/S.

  12. TUG1 promotes lens epithelial cell apoptosis by regulating miR-421/caspase-3 axis in age-related cataract.

    Science.gov (United States)

    Li, Guoxing; Song, Huiyang; Chen, Lei; Yang, Weihua; Nan, Kaihui; Lu, Peirong

    2017-07-01

    Age-related cataract is among the most common chronic disorders of ageing and the apoptosis of lens epithelial cells contributes to non-congenital cataract development. We amid to explore the role of TUG1 and miR-421 in the age-related cataract. The expression level of TUG1, miR-421 and caspase-3 were detected by RT-qPCR. The apoptotic-related protein, caspase-3, Bax and blc-2 were analyzed by western blot. We performed ultraviolet (UV) irradiation to induce SAR01/04 cell apoptosis which was analyzed by flow cytometry. RIP pull-down and luciferase reporter assay were used to verified the combination and regulating among TUG1, miR-421 and caspase-3. Here, we observed that the expression level of TUG1 and caspase-3 in the anterior lens capsules of age-related cataract were significantly higher and miR-421 was significantly lower than that in the normal anterior lens capsules. The apoptosis-related protein, caspase-3, Bax and blc-2 were abnormal expression in the anterior lens capsules of age-related cataract tissue. Our data showed that the expression level of TUG1 and caspase-3 and cell apoptosis rate in SAR01/04 cells treated with UV irradiation was remarkably higher than that in the control. TUG1 negatively regulated miR-421 expression and promoted UV irradiation-induced SAR01/04 cell apoptosis. However, miR-421 inhibitor and pcDNA-caspase-3 could reverse the action of the SRA01/04 cell apoptosis by si-TUG1, which suggested TUG1 promoted UV irradiation-induced apoptosis through downregulating miR-421 expression. Furthermore, this study confirmed TUG1 could been in combination with miR-421, and TUG1 and caspase-3 were both a directly target of miR-421. TUG1 modulated lens epithelial cell apoptosis through miR-421/caspase-3 axis. These findings will offer a novel insight into the pathogenesis of cataract. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Practical protective tools for occupational exposure: 1) double focus spectacles for the aged with highly refracted glass lens 2) remodeled barrier for radiation protection.

    Science.gov (United States)

    Kurokawa, S; Yabe, S; Takamura, A; Ishizaki, H; Aizawa, S

    2000-11-30

    Two practical protective tools for occupational exposure for neurointerventional radiologists are presented. The first purpose of this study was to investigate the effectiveness of double focus spectacles for the aged with a highly refracted glass lens (special spectacles for the aged) for radiation protection of the crystalline lens of the eye in comparison with other spectacles on the market, based on the measurement of film density which was obtained by exposure of X-ray through those spectacles. As a result of the film densitometry mentioned above, the effectiveness of special spectacles for the aged in radiation protection was nearly equal to the effectiveness of a goggle type shield which is made with a 0.07 mm lead-equivalent plastic lens. The second purpose of this study was to investigate the effectiveness of the protective barrier, which we remodeled for cerebral angiography or neuroendovascular therapy, for radiation exposure, based on the measurement in a simulated study with a head phantom, and on the measurement of radiation exposure in operaters during procedures of clinical cases. In the experimental study radiation exposure in supposed position of the crystalline lens was reduced to about one third and radiation exposure in supposed position of the gonadal glands was reduced to about one seventh, compared to radiation exposure without employing the barrier. The radiation exposure was monitored at the left breast of three radiologists, in 215 cases of cerebral angiography. Employing the barrier in cerebral angiography, average equivalent dose at the left breast measured 1.49mu Sv during 10 min of fluoroscopy. In three kinds of neuroendovascular therapy in 40 cases, radiation exposure in an operator was monitored in the same fashion and the dose was recorded less than the result reported in previous papers in which any protective barrier have not been employed in the procedure (1,2). As a result, the two above mentioned protective tools are

  14. Objective lens

    Science.gov (United States)

    Olczak, Eugene G. (Inventor)

    2011-01-01

    An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

  15. Advances in hard nucleus cataract surgery

    Directory of Open Access Journals (Sweden)

    Wei Cui

    2013-11-01

    Full Text Available Security and perfect vision and fewer complications are our goals in cataract surgery, and hard-nucleus cataract surgery is always a difficulty one. Many new studies indicate that micro-incision phacoemulsification in treating hard nucleus cataract is obviously effective. This article reviews the evolution process of hard nuclear cataract surgery, the new progress in the research of artificial intraocular lens for microincision, and analyse advantages and disadvantages of various surgical methods.

  16. Age-related changes in the lateral lipid distribution in a human lens described by mass spectrometry imaging

    Czech Academy of Sciences Publication Activity Database

    Pól, Jaroslav; Faltýsková, Helena; Krásný, Lukáš; Volný, Michael; Vláčil, O.; Hajdúch, M.; Lemr, Karel; Havlíček, Vladimír

    2015-01-01

    Roč. 21, č. 3 (2015), s. 297-303 ISSN 1469-0667 R&D Projects: GA MŠk(CZ) LD13038; GA MŠk LO1509 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 Keywords : lens * eye * imaging Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.011, year: 2015

  17. Galanin neurons in the intermediate nucleus (InM) of the human hypothalamus in relation to sex, age, and gender identity.

    Science.gov (United States)

    Garcia-Falgueras, Alicia; Ligtenberg, Lisette; Kruijver, Frank P M; Swaab, Dick F

    2011-10-15

    The intermediate nucleus (InM) in the preoptic area of the human brain, also known as the sexually dimorphic nucleus of the preoptic area (SDN-POA) and the interstitial nucleus of the anterior hypothalamus-1 (INAH-1) is explored here. We investigated its population of galanin-immunoreactive (Gal-Ir) neurons in relation to sex, age, and gender identity in the postmortem brain of 77 subjects. First we compared the InM volume and number of Gal-Ir neurons of 22 males and 22 females in the course of aging. In a second experiment, we compared for the first time the InM volume and the total and Gal-Ir neuron number in 43 subjects with different gender identities: 14 control males (M), 11 control females (F), 10 male-to-female (MtF) transsexual people, and 5 men who were castrated because of prostate cancer (CAS). In the first experiment we found a sex difference in the younger age group ( 45 years. In the second experiment the MtF transsexual group presented an intermediate value for the total InM neuron number and volume that did not seem different in males and females. Because the CAS group did not have total neuron numbers that were different from the intact males, the change in adult circulating testosterone levels does not seem to explain the intermediate values in the MtF group. Organizational and activational hormone effects on the InM are discussed. Copyright © 2011 Wiley-Liss, Inc.

  18. [Magnetic resonance imaging study of effects of accommodation on human lens morphological characters].

    Science.gov (United States)

    Zheng, Sui-lian; Zhang, Ai; Shi, Jian-jing; Zhou, Yun-xin

    2013-11-05

    To evaluate the effects of accommodation on lens morphological characters. From January 2011 to June 2011, magnetic resonance images of eyes were acquired from 30 subjects aged 20 to 24 years during accommodation and at rest. The optimal images were analyzed by Autocad 2010 to obtain the total lens cross-sectional area (CSA) and CSA of anterior and posterior portions of lens, anterior chamber depth, lens thickness, lens diameter, vitreous chamber depth and axial length during accommodation and at rest. Paired-t test was performed. The anterior curvature radius (mm), posterior curvature radius (mm), CSA of anterior portion (mm(2)), CSA of posterior portion (mm(2)), total lens CSA (mm(2)) was (8.7 ± 0.8), (6.2 ± 0.5), (7.5 ± 2.1), (12.0 ± 2.6), (20 ± 4) during relaxed accommodation; anterior curvature radius (mm), posterior curvature radius (mm), CSA of anterior portion (mm(2)), CSA of posterior portion (mm(2)), total lens CSA (mm(2)) was (7.1 ± 1.3), (5.6 ± 0.5), (14.7 ± 2.9), (12.2 ± 2.1) and (27 ± 4) during accommodation. The total lens CSA (t = -11.556, P 0.05) under a statistically independent accommodative state. There was significant difference in the anterior chamber depth (t = 4.366, P 0.05) and axial length (t = 0.418, P > 0.05) under accommodative states. During accommodation, the anterior chamber depth decreases, lens thickness increases and diameter of lens decreases while anterior portions and total lens CSA increase. There are insignificant changes in posterior portions of lens CSA, vitreous chamber depth and axial length. The accommodative changes in CSA indicate that the anterior portion of lens may be related with the properties of anterior capsule and lens material, the position of zonular attachments and the location of fetal nucleus. Helmholtz theory is supported.

  19. Three-Dimensional Cataract Crystalline Lens Imaging With Swept-Source Optical Coherence Tomography.

    Science.gov (United States)

    de Castro, Alberto; Benito, Antonio; Manzanera, Silvestre; Mompeán, Juan; Cañizares, Belén; Martínez, David; Marín, Jose María; Grulkowski, Ireneusz; Artal, Pablo

    2018-02-01

    To image, describe, and characterize different features visible in the crystalline lens of older adults with and without cataract when imaged three-dimensionally with a swept-source optical coherence tomography (SS-OCT) system. We used a new SS-OCT laboratory prototype designed to enhance the visualization of the crystalline lens and imaged the entire anterior segment of both eyes in two groups of participants: patients scheduled to undergo cataract surgery, n = 17, age range 36 to 91 years old, and volunteers without visual complains, n = 14, age range 20 to 81 years old. Pre-cataract surgery patients were also clinically graded according to the Lens Opacification Classification System III. The three-dimensional location and shape of the visible opacities were compared with the clinical grading. Hypo- and hyperreflective features were visible in the lens of all pre-cataract surgery patients and in some of the older adults in the volunteer group. When the clinical examination revealed cortical or subcapsular cataracts, hyperreflective features were visible either in the cortex parallel to the surfaces of the lens or in the posterior pole. Other type of opacities that appeared as hyporeflective localized features were identified in the cortex of the lens. The OCT signal in the nucleus of the crystalline lens correlated with the nuclear cataract clinical grade. A dedicated OCT is a useful tool to study in vivo the subtle opacities in the cataractous crystalline lens, revealing its position and size three-dimensionally. The use of these images allows obtaining more detailed information on the age-related changes leading to cataract.

  20. Influence of age-related changes in nitric oxide synthase-expressing neurons in the rat supraoptic nucleus on inhibition of salivary secretion.

    Science.gov (United States)

    Tanaka, Takehiko; Tamada, Yoshitaka; Suwa, Fumihiko

    2008-02-01

    Age-related inhibition of salivary secretion has been demonstrated in rats, and the nitric oxide (NO) present in the supraoptic nucleus (SON) and the medial septal area has been reported to play an inhibitory role in the regulation of salivary secretion. In the present study, we investigated the age-related changes occurring in the NO synthase (NOS)-expressing neurons in the SON, which is related to the production of NO, and discussed the interrelation between the age-related changes in the NOS-expressing neurons and the age-related inhibition of salivary secretion. Nissl staining and reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry were performed for young adult and aged rats. Quantitative analysis was also performed using the Nissl-stained and NADPH-d-positive neurons. Although the numbers of the Nissl-stained neurons did not change, significant age-related increases were detected in cell number, cell size and reactive density of the NADPH-d-positive neurons. Therefore, the production of NO in the SON neurons increased with age. We concluded that the age-related increase in the NO in the SON might be a factor that contributes to the age-related inhibition of salivary secretion.

  1. [Concentration of monoamines and activity of several enzymes in the arcuate nucleus of the hypothalamus in young and aging rats during the estrous cycle].

    Science.gov (United States)

    Grantyn', V A

    1976-07-01

    The arcuate nucleus (AN) and the median eminence (ME) of the hypothalamus were investigated in young and ageing female rats. During the estral cycle (EC) the monoamine (MA) content, the monoaminoxidase (MAO), NADP and NAD-diaphorase activities were determined in the AN, and the MA content and the activity of alkaline phosphatase (AP) -- in the ME. In young rats in the proestrus-estrus there was an increase in the activity of the NADP and NAD-diaphorase and of the MA content, but a decrease of the MAO activity. This indicated an intensified function of the nucleus at these stages of the EC. Accumulation of the MA in the ME was noted in the diestrus, while in the proestrus their concentration sharply fell; on the other hand, the activity of the AP was considerably increased. In the ageing rats the dynamics of the indices under study during the EC were largely unchanged. However, the functional activity of the AN proved to increase, and in the ME and elevation of the MA concentration and disturbance of its release from the nerve terminals was seen.

  2. Crystalline lens power and refractive error.

    Science.gov (United States)

    Iribarren, Rafael; Morgan, Ian G; Nangia, Vinay; Jonas, Jost B

    2012-02-01

    To study the relationships between the refractive power of the crystalline lens, overall refractive error of the eye, and degree of nuclear cataract. All phakic participants of the population-based Central India Eye and Medical Study with an age of 50+ years were included. Calculation of the refractive lens power was based on distance noncycloplegic refractive error, corneal refractive power, anterior chamber depth, lens thickness, and axial length according to Bennett's formula. The study included 1885 subjects. Mean refractive lens power was 25.5 ± 3.0 D (range, 13.9-36.6). After adjustment for age and sex, the standardized correlation coefficients (β) of the association with the ocular refractive error were highest for crystalline lens power (β = -0.41; P lens opacity grade (β = -0.42; P lens power (β = -0.95), lower corneal refractive power (β = -0.76), higher lens thickness (β = 0.30), deeper anterior chamber (β = 0.28), and less marked nuclear lens opacity (β = -0.05). Lens thickness was significantly lower in eyes with greater nuclear opacity. Variations in refractive error in adults aged 50+ years were mostly influenced by variations in axial length and in crystalline lens refractive power, followed by variations in corneal refractive power, and, to a minor degree, by variations in lens thickness and anterior chamber depth.

  3. Correlation of catecholamine levels in the bed nucleus of the stria terminalis and reduced sexual behavior in middle-aged male rats.

    Science.gov (United States)

    Chen, Joyce C; Tsai, Houng-Wei; Yeh, Kuei-Ying; Tai, Mei-Yun; Tsai, Yuan-Feen

    2008-07-01

    The correlation between dopamine (DA) and norepinephrine (NE) levels in the bed nucleus of the stria terminalis (BNST) and male sexual behavior was examined in middle-aged rats. Male rats (18-19 months) were divided into: (a) Group MIE, consisting of rats showing mounts, intromissions, and ejaculations; (b) Group MI, composed of rats showing mounts and intromissions, but no ejaculation; and (c) Group NC, consisting of noncopulators. Young adult rats (4-5 months) displaying complete copulatory behavior were used as the control. Tissue levels of DA, NE, and DA metabolites in the BNST were measured by high-pressure liquid chromatography. DA, but not NE, levels in MIE rats were significantly lower than those in young controls. DA and NE levels in MIE rats were significantly higher than those in NC rats. These results suggest that DA and NE in the BNST might play an important role in the control of male sexual behavior in middle-aged rats.

  4. The nucleus

    International Nuclear Information System (INIS)

    Marano, S.

    1998-01-01

    In 1911 E.Rutherford discovered the nucleus. Since then the nucleus has been investigated with more and more powerful tools but it remains the main field of study of nuclear physics. As it is impossible to take into account the interaction of all the nucleons, a theory based on the hypothesis that each nucleon undergoes an average interaction force has been set up. 2 representations have emerged: the Skyrme force and the Gogny force. Both representations match experimental results but are unable to describe fission yields or the multi-fragmentation of very hot nuclei. The mean-field theory can predict the shape of the nuclei according to its energy level. An experimental program involving the Vivitron accelerator and the Euroball detector is due to begin to validate it. By bombarding targets with exotic nuclei nuclear physicists detect new structures and test their collision models. About ten years ago nuclear halos were observed with lithium 11 nuclei. In this nucleus 2 neutrons move in a space larger than the nucleus itself. This discovery has triggered the elaboration of new theories based on nuclear clusters. At very high temperatures the mean-field theory predicts that nuclear matter acts as a fluid. Following the nuclei temperature different ways of decay appear: first evaporation then multi-fragmentation and vaporization. This ultimate stage occurs around 100 milliard celsius degree temperature when the nuclei decays in a multitude of light particles. Isomeric states are studied and could be seen as a way of storing energy. In a very pedagogical way this article gives information to understand the challenges that face nuclear physics today and highlights the contributions of Cea in this field. (A.C.)

  5. Galanin neurons in the intermediate nucleus (InM) of the human hypothalamus in relation to sex, age, and gender identity

    NARCIS (Netherlands)

    Garcia-Falgueras, Alicia; Ligtenberg, Lisette; Kruijver, Frank P. M.; Swaab, Dick F.

    2011-01-01

    The intermediate nucleus (InM) in the preoptic area of the human brain, also known as the sexually dimorphic nucleus of the preoptic area (SDN-POA) and the interstitial nucleus of the anterior hypothalamus-1 (INAH-1) is explored here. We investigated its population of galanin-immunoreactive (Gal-Ir)

  6. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil...

  7. Nucleus-nucleus total reaction cross sections

    International Nuclear Information System (INIS)

    DeVries, R.M.; Peng, J.C.

    1980-01-01

    We compare sigma/sub R/(E) for nucleus-nucleus systems (obtained from existing direct measurements and derived from elastic scattering data) with nucleon-nucleon and nucleon-nucleus data. The energy dependence of sigma/sub R/(E) for nucleus-nucleus systems is found to be quite rapid; there appears to be no evidence for an energy independent, geometric sigma/sub R/. Simple parameter free microscopic calculations are able to quantitatively reproduce the data and thus, emphasize the dominance of nucleon-nucleon interactions in medium energy nucleus-nucleus collisions

  8. Radiocarbon Dating of the Human Eye Lens Crystallines Reveal Proteins without Carbon Turnover throughout Life

    Science.gov (United States)

    Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen; Jacobsen, Christina; Heinemeier, Jan

    2008-01-01

    Background Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule) completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its 14C content from the atmospheric carbon dioxide. The 14C content of the lens proteins thus reflects the atmospheric content of 14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the 14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric 14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. Methodology/Principal Findings Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. Conclusions/Significance Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the 14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA). Potential targets may be nervous tissues in terms of senile or pre-senile degradation, as well as other highly

  9. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life.

    Directory of Open Access Journals (Sweden)

    Niels Lynnerup

    Full Text Available BACKGROUND: Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14C content from the atmospheric carbon dioxide. The (14C content of the lens proteins thus reflects the atmospheric content of (14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the (14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. METHODOLOGY/PRINCIPAL FINDINGS: Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. CONCLUSIONS/SIGNIFICANCE: Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the (14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA. Potential targets may be nervous tissues in terms of senile or pre

  10. Age-related changes in the transmission properties of the human lens and their relevance to circadian entrainment

    DEFF Research Database (Denmark)

    Kessel, Line; Lundeman, Jesper Holm; Herbst, Kristina

    2010-01-01

    To characterize age-related changes in the transmission of light through noncataractous human lenses.......To characterize age-related changes in the transmission of light through noncataractous human lenses....

  11. Treatment of a dislocated lens by transcorneal vitrectomy and bimanual phacoemulsification

    Directory of Open Access Journals (Sweden)

    Watanabe A

    2014-08-01

    Full Text Available Akira Watanabe, Tamaki Gekka, Hiroshi Tsuneoka Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan Background: As a method of treatment for a dropped lens nucleus, which occurred during cataract surgery, the dropped lens nucleus was removed through the corneal wound without using pars plana vitrectomy (PPV. After vitrectomy, the dropped lens nucleus was floated on the perfluorocarbon liquid (PFCL. The floating lens nucleus was then phacoemulsified and aspirated. During surgery, irrigation from the anterior chamber was performed. This method was very effective for treatment of a dropped hard nucleus.Case report: During cataract surgery on the left eye of an 80-year-old woman, a posterior capsule rupture occurred. As a result, the lens nucleus dropped into the vitreous cavity. Irrigation to the anterior chamber was performed, with an anterior chamber maintainer inserted through a newly created side port at the corneal limbus. A vitreous cutter and a light guide were inserted in order to perform vitrectomy through the corneal incisions that were created for the cataract surgery. After vitrectomy, the dropped lens nucleus was floated using PFCL. The floating lens nucleus was removed by a bimanual phacoemulsification technique, with the anterior chamber irrigation continuing. The separation of the irrigation port and the aspiration port allowed for effective treatment of the dropped nucleus that was floating on the PFCL, even using a ­phacoemulsification machine with a peristaltic pump system. Safe and effective vitrectomy, similar to a PPV, could be performed with this method using three corneal ports.Conclusion: This technique may allow safer and more effective treatment for a dropped lens nucleus compared with conventional PPV. With this technique, corneal distortion due to surgical manipulation can lead to reduced visibility of the posterior eye. Keywords: dislocated lens, transcorneal vitrectomy, bimanual

  12. Chemical aging of single and multicomponent biomass burning aerosol surrogate particles by OH: implications for cloud condensation nucleus activity

    Directory of Open Access Journals (Sweden)

    J. H. Slade

    2015-09-01

    Full Text Available Multiphase OH and O3 oxidation reactions with atmospheric organic aerosol (OA can influence particle physicochemical properties including composition, morphology, and lifetime. Chemical aging of initially insoluble or low-soluble single-component OA by OH and O3 can increase their water solubility and hygroscopicity, making them more active as cloud condensation nuclei (CCN and susceptible to wet deposition. However, an outstanding problem is whether the effects of chemical aging on their CCN activity are preserved when mixed with other organic or inorganic compounds exhibiting greater water solubility. In this work, the CCN activity of laboratory-generated biomass burning aerosol (BBA surrogate particles exposed to OH and O3 is evaluated by determining the hygroscopicity parameter, κ, as a function of particle type, mixing state, and OH and O3 exposure applying a CCN counter (CCNc coupled to an aerosol flow reactor (AFR. Levoglucosan (LEV, 4-methyl-5-nitrocatechol (MNC, and potassium sulfate (KS serve as representative BBA compounds that exhibit different hygroscopicity, water solubility, chemical functionalities, and reactivity with OH radicals, and thus exemplify the complexity of mixed inorganic/organic aerosol in the atmosphere. The CCN activities of all of the particles were unaffected by O3 exposure. Following exposure to OH, κ of MNC was enhanced by an order of magnitude, from 0.009 to ~ 0.1, indicating that chemically aged MNC particles are better CCN and more prone to wet deposition than pure MNC particles. No significant enhancement in κ was observed for pure LEV particles following OH exposure. κ of the internally mixed particles was not affected by OH oxidation. Furthermore, the CCN activity of OH-exposed MNC-coated KS particles is similar to the OH unexposed atomized 1 : 1 by mass MNC : KS binary-component particles. Our results strongly suggest that when OA is dominated by water-soluble organic carbon (WSOC or inorganic ions

  13. [fs-Lentotomy: presbyopia reversal by generating gliding planes inside the crystalline lens].

    Science.gov (United States)

    Lubatschowski, H; Schumacher, S; Wegener, A; Fromm, M; Oberheide, U; Hoffmann, H; Gerten, G

    2009-12-01

    Based on the Helmholtz theory for accommodation, increasing sclerosis of the lens nucleus and cortex is the main cause for the development of presbyopia. Existing therapies, however, do not reverse the stiffness of the crystalline lens and thus do not regain real accommodation ability. A new approach to restore the flexibility of the lens has been realised by utilising the non-linear interaction of ultrafast laser pulses with transparent tissue, the so-called photodisruption. This process has been used to create micro-incisions which act as gliding planes inside the crystalline lens without opening the eye globe. This treatment method, known as fs-lentotomy, enables regeneration of real dynamic accommodation. For the first time, 3D structures for gliding planes were successfully generated in experiments with human donor lenses of different ages. An average increase in anterior-posterior lens thickness of 100 mum accompanied by a decrease of equatorial lens diameter was observed as a direct consequence of fs-lentotomy. This is attributed to the increased flexibility, as the force of the capsule bag moulds the lens tissue more spherically. Moreover, in vivo experiments on rabbit eye lenses did not induce an increasing opacification (cataract) over a six-month follow-up period. However, the incisions were still detectable using Scheimpflug imaging and histopathological techniques, although the visibility of the incisions was declining. Furthermore, no side effects were observed during the wound healing process and during a six-months follow-up period. Based on these findings fs-lentotomy might have the potential to become a procedure for the reversal of presbyopia. Copyright Georg Thieme Verlag KG Stuttgart . New York.

  14. Pigmented striae of the anterior lens capsule and age-associated pigment dispersion of variable degree in a group of older African-Americans: an age, race, and gender matched study.

    Science.gov (United States)

    Roberts, D K; Winters, J E; Castells, D D; Clark, C A; Teitelbaum, B A

    2001-01-01

    To investigate pigmented striae of the anterior lens capsule in African-Americans, a potential indicator of significant anterior segment pigment dispersion. A group of 40 African-American subjects who exhibited pigmented lens striae (PLS) were identified from a non-referred, primary eye care population in Chicago, IL, USA. These subjects were then compared to an age, race, and gender matched control group relative to refractive error and the presence or absence of diabetes and hypertension. The PLS subjects (mean age = 65.4 +/- 8.8 years, range = 50-87 years) consisted of 36 females and 4 males. PLS were bilateral in 36 (85%) of the 40 subjects. Among the eyes with PLS, 21 (55%) of 38 right eyes and 22 (61%) of 36 left eyes also had significant corneal endothelial pigment dusting, commonly in the shape of a Krukenberg's spindle. Ten (25%) of the PLS subjects had either glaucoma or ocular hypertension (7 bilateral, 3 unilateral). The presence of trabecular meshwork pigment varied from minimal to heavy. The mean +/- SD (range) refractive error of the PLS right eyes was +1.61 +/- 1.43D (-1.50 to +5.00D) and +1.77 +/- 1.37D (-1.00 to +5.00D) for the left eyes. Based on these data, the PLS right eyes were +1.63D (Student's t, p = 0.0001; 95% CI = +0.82 to +2.44D) more hyperopic on average than the control right eyes, and the PLS left eyes were +1.77D (p = 0.0001; 95% CI = +0.92 to +2.63D) more hyperopic on average than the control left eyes. Trend analysis showed a gradually increasing likelihood of PLS with increasing magnitude of hyperopia in both eyes (Mantel-Haenszel chi-square, p = 0.001). Among PLS subjects, 24 (60%) of 40 were hypertensive and 9 (23%) of 40 were diabetic. However, these proportions were not significantly different (two-tailed Fisher's exact test; hypertension: p = 0.30; diabetes: p = 0.70) from the randomly selected controls. Among our African-American group, which consisted predominately of females >50 years of age, the likelihood of PLS

  15. Age-related differences in signaling efficiency of human lens cells underpin differential wound healing response rates following cataract surgery.

    Science.gov (United States)

    Dawes, Lucy Jean; Duncan, George; Wormstone, Ian Michael

    2013-01-14

    Cataract surgery is blighted by posterior capsule opacification (PCO), which is more severe and frequent in the young than the elderly (>60 years). Our aim was to understand the biological basis for these age-related differences in PCO/wound healing rates. Human capsular bags were prepared by cataract surgery on donor lenses (young [60 years] groups) and maintained in serum-free Eagle's minimum essential medium. Cell growth was determined using the MTS assay. Fibroblast growth factor (FGF) and hepatocyte growth factor (HGF) levels were determined using ELISA. Protein synthesis rates were elucidated by 35S-methionine incorporation. U0126, SB203580, and SP600125 were used to disrupt ERK-, p38-, and JNK-mediated signaling, respectively. Level of total and phospho-ERK, -c-jun, -P38, and -JNK plus cytokines were detected using a BIOPLEX array system. Following a 2-day culture period, significant decreases in IL-1β and IL-6, and increases in IL-10, IL-12, IL-13, and VEGF in the >60 years group were observed compared with their younger counterparts. Capsular bags (cells and capsule) from aged donors contained greater than or equal levels of HGF and FGF than younger counterparts and had greater rates of protein synthesis. Inhibition of ERK, p38, and JNK signaling significantly suppressed cell coverage on the posterior capsule. pERK, p-c-jun, p-p38, and pJNK were consistently lower in aged cell populations; total signaling protein expression was unaffected by age. Serum stimulation increased pERK, p-c-jun, and pJNK levels in cells of all ages; p-p38 was significantly increased in the >60 years group only. Ligand availability to cells is not a limiting factor as we age, but the ability to convert this resource into signaling activity is. We therefore propose that overall signaling efficiency is reduced as a function of age, which consequently limits wound-healing response rates after injury.

  16. Analysis of newspaper coverage of active aging through the lens of the 2002 World Health Organization Active Ageing Report: A Policy Framework and the 2010 Toronto Charter for Physical Activity: A Global Call for Action.

    Science.gov (United States)

    Abdullah, Boushra; Wolbring, Gregor

    2013-12-05

    As populations continue to grow older, efforts to support the process of aging well are important goals. Various synonyms are used to cover aging well, such as active aging. The World Health Organization published in 2002 the report Active Ageing: A Policy Framework that according to the call for papers, has brought active ageing to the forefront of international public health awareness. The 2010 Toronto Charter for Physical Activity: A Global Call for Action was singled out in the call for papers as a key document promoting physical activity one goal of the 2002 WHO active aging policy framework. Media are to report to the public topics of importance to them. We investigated the newspaper coverage of aging well and synonymous terms such as active aging through the lens of the 2002 WHO active aging policy framework and the 2010 Toronto Charter for Physical Activity. As sources we used the following newspapers: China Daily, The Star (Malaysia), two UK newspapers (The Guardian, The Times), a database of 300 Canadian newspapers (Canadian Newsstand) and a US newspaper (The New York Times). The study generated data answering the following four research questions: (1) how often are the 2002 WHO active aging policy framework and the 2010 Toronto Charter for Physical Activity mentioned; (2) how often is the topic of active aging and terms conveying similar content (aging well, healthy aging, natural aging and successful aging) discussed; (3) which of the issues flagged as important in the 2002 WHO active aging policy framework and the 2010 Toronto Charter for Physical Activity are covered in the newspaper coverage of active aging and synonymous terms; (4) which social groups were mentioned in the newspapers covered. The study found a total absence of mentioning of the two key documents and a low level of coverage of "active aging" and terms conveying similar content. It found further a lack of engagement with the issues raised in the two key documents and a low level of

  17. Crystalline lens and refractive development.

    Science.gov (United States)

    Iribarren, Rafael

    2015-07-01

    Individual refractive errors usually change along lifespan. Most children are hyperopic in early life. This hyperopia is usually lost during growth years, leading to emmetropia in adults, but myopia also develops in children during school years or during early adult life. Those subjects who remain emmetropic are prone to have hyperopic shifts in middle life. And even later, at older ages, myopic shifts are developed with nuclear cataract. The eye grows from 15 mm in premature newborns to approximately 24 mm in early adult years, but, in most cases, refractions are maintained stable in a clustered distribution. This growth in axial length would represent a refractive change of more than 40 diopters, which is compensated by changes in corneal and lens powers. The process which maintains the balance between the ocular components of refraction during growth is still under study. As the lens power cannot be measured in vivo, but can only be calculated based on the other ocular components, there have not been many studies of lens power in humans. Yet, recent studies have confirmed that the lens loses power during growth in children, and that hyperopic and myopic shifts in adulthood may be also produced by changes in the lens. These studies in children and adults give a picture of the changing power of the lens along lifespan. Other recent studies about the growth of the lens and the complexity of its internal structure give clues about how these changes in lens power are produced along life. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Converging or Diverging Lens?

    Science.gov (United States)

    Branca, Mario

    2013-01-01

    Why does a lens magnify? Why does it shrink objects? Why does this happen? The activities that we propose here are useful in helping us to understand how lenses work, and they show that the same lens can have different magnification capabilities. A converging lens can also act as a diverging lens. (Contains 4 figures.)

  19. Physical hydrogeology and environmental isotopes to constrain the age, origins, and stability of a low-salinity groundwater lens formed by periodic river recharge: Murray Basin, Australia

    Science.gov (United States)

    Cartwright, Ian; Weaver, Tamie R.; Simmons, Craig T.; Fifield, L. Keith; Lawrence, Charles R.; Chisari, Robert; Varley, Simon

    2010-01-01

    SummaryA low-salinity (total dissolved solids, TDS, Australia. Hydraulic heads, surface water elevations, δ 18O values, major ion geochemistry, 14C activities, and 3H concentrations show that the lens is recharged from the Murray River largely through the riverbank with limited recharge through the floodplain. Recharge of the lens occurs mainly at high river levels and the low-salinity groundwater forms baseflow to some river reaches during times of low river levels. Within the lens, flow through the shallow Channel Sands and deeper Parilla Sands aquifers is sub-horizontal. While the Blanchetown Clay locally separates the Channel Sands and the Parilla Sands, the occurrence of recently recharged low-salinity groundwater below the Blanchetown Clay suggests that there is considerable leakage through this unit, implying that it is not an efficient aquitard. The lateral margin of the lens with the regional groundwater (TDS >25,000 mg/L) is marked by a hectometer to kilometer scale transition in TDS concentrations that is not stratigraphically controlled. Rather this boundary represents a mixing zone with the regional groundwater, the position of which is controlled by the rate of recharge from the river. The lens is part of an active and dynamic hydrogeological system that responds over years to decades to changes in river levels. The lens has shrunk during the drought of the late 1990s to the mid 2000s, and it will continue to shrink unless regular high flows in the Murray River are re-established. Over longer timescales, the rise of the regional water table due to land clearing will increase the hydraulic gradient between the regional groundwater and the groundwater in the lens, which will also cause it to degrade. Replacement of low-salinity groundwater in the lens with saline groundwater will ultimately increase the salinity of the Murray River reducing its utility for water supply and impacting riverine ecosystems.

  20. The atomic nucleus as a target

    International Nuclear Information System (INIS)

    Strugalski, Z.; Pawlak, T.

    1981-01-01

    The purpose of this article is to characterize the atomic nucleus used as a target in hadron-nucleus collision experiments. The atomic nucleus can be treated as a lens-shaped ''slab'' of nuclear matter. Such ''slab'' should be characterized by the nuclear matter layer thickness at any impact parameter, by its average thickness, and by its maximal thickness. Parameters characterizing atomic nuclei as targets are given for the elements: 6 12 C, 7 14 N, 8 16 O, 9 19 F, 10 20 Ne, 13 27 Al, 14 28 Si, 16 32 S, 18 40 Ar, 24 52 Cr, 26 54 Fe, 27 59 Co, 29 64 Cu, 30 65 Zn, 32 73 Ge, 35 80 Br, 47 100 Ag, 53 127 I, 54 131 Xe, 73 181 Ta, 74 184 W, 79 197 Au, 82 207 Pb, 92 -- 238 U [ru

  1. Stereotactic localization and visualization of the subthalamic nucleus

    Institute of Scientific and Technical Information of China (English)

    SHEN Wei-gao; WANG Hai-yang; LIN Zhi-guo; SHEN Hong; CHEN Xiao-guang; FU Yi-li; GAO Wen-peng

    2009-01-01

    Background The subthalamic nucleus (STN) is widely recognized as one of the most important and commonly targeted nuclei in stereotactic and functional neurosurgery. The success of STN surgery depends on accuracy in target determination. Construction of a digitalized atlas of STN based on stereotactic MRI will play an instrumental role in the accuracy of anatomical localization. The aim of this study was to investigate the three-dimensional (3D) target location of STN in stereotactic space and construct a digitalized atlas of STN to accomplish the visualization of the STN on stereotactic MRI, thus providing clinical guidance on the precise anatomical localization of STN.Methods One hundred and twenty healthy people volunteered to be scanned by 1.5 Tesla MRI scanning with 1-mm-thick slice in the standard stereotactic space between 2005 and 2006. One adult male was selected for 3D reconstruction of STN. The precess of 3D reconstruction included identification, manual segmentation, extraction,conservation and reconstruction.Results There was a significant correlation between the coordinates and age (P <0.05). The volume of left STN was significantly larger than the right STN, and there was a significant negative correlation between volume and age (P <0.05).The surface of the STN nucleus after 3D reconstruction appeared smooth, natural and realistic. The morphological feature of STN on the individual brain could be visualized directly in 3D. The 3D reconstructed STN could be rotated,zoomed and displayed at any direction in the stereotactic space. The anteroposterior diameter of the STN nucleus was longer than the vertical and transverse diameters in 3D space. The 3D reconstruction of STN manifested typical structure of the "dual lens".Conclusions The visualization of individual brain atlas based on stereotactic MRI is feasible. However, software for automated segmentation, extraction and registration of MR images need to be further developed.

  2. Perspective of ultrarelativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Specht, H.J.

    1985-01-01

    The paper concerns the lectures given at the International School of nuclear physics, Erice, 1985, which survey the expectations for the field of ultrarelativistic nucleus-nucleus collisions. The primary motivation for the field, the organization of the lectures, and a description of the NA 34 experiment, are all briefly given. (U.K.)

  3. High energy nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Bhalla, K.B.

    1980-01-01

    An attempt is made to explain nucleus-nucleus collisions based on nuclear emulsion experiments. Peripheral and central collisions are described in detail. Assuming the fireball model, the concepts of geometry, kinematics and thermodynamics in this model are discussed. Projectile and target fragmentations are studied. The advantages of using nuclear emulsions as detectors, are mentioned. Proton-nucleus collisions and nucleus-nucleus collisions are compared. Interactions, of projectiles such as Ca, B and C on targets such as Pb, Ag, Br etc. at very high energies (approximately 300 to 1700 Gev) are listed. A comparison of the near multiplicities in these interactions is given. A generalized explanation is given on the processes involved in these interactions. (A.K.)

  4. Single lens to lens duplication: The missing link

    OpenAIRE

    Bhatt, Rupal; Jethani, Jitendra; Saluja, Praveen; Bharti, Vinay

    2008-01-01

    Congenital anomalies of the lens include a wide range from lens coloboma to primary aphakia and doubling of lens. There have been few case reports of double lens; the etiology suggested is metaplastic changes in the surface ectoderm that leads to formation of two lens vesicles and hence resulting in double lens. We report a case with bilobed lens, which raises the possibility of explaining the etiology of double lens.

  5. Hippocampus, caudate nucleus and entorhinal cortex volumetric MRI measurements in discrimination between Alzheimer’s disease, mild cognitive impairment, and normal aging

    Directory of Open Access Journals (Sweden)

    Rasha Elshafey

    2014-06-01

    Conclusion: Semi-automated MR volumetric measurements can be used to determine atrophy in hippocampus, caudate nucleus and entorhinal cortex which aided in discrimination of healthy elderly control subjects from subjects with AD and MCI and predict clinical decline of MCI leading to increase the efficiency of clinical treatments, delay institutionalization and improve cognition and behavioral symptoms.

  6. Onuf's nucleus X

    DEFF Research Database (Denmark)

    Schrøder, H D

    1981-01-01

    in the length of the nucleus was observed. Based on the cytoarchitecture the nucleus could be divided in three parts, a cranial, a dorsomedial and a ventrolateral. All parts of the nucleus consisted of chromatin-rich medium-sized neurons, and apparent direct appositions between different cells bodies as well...

  7. Contact Lens Care

    Science.gov (United States)

    ... Consumers Consumer Information by Audience For Women Contact Lens Care Share Tweet Linkedin Pin it More sharing ... www.fda.gov/medwatch Learn More about Contact Lens Care Other Tips on Contact Lenses Decorative Contact ...

  8. Pion production in nucleus--nucleus collisions

    International Nuclear Information System (INIS)

    Schroeder, L.S.

    1975-06-01

    Current work on pion production in high-energy nucleus-nucleus collisions is reviewed. The majority of existing data are of the inclusive variety in which a single final state pion is detected. Experimental data are compared and their possible contributions to obtaining new information on nuclear structure is discussed. Various models which attempt to explain the observed single-inclusive-pion spectra either on the basis of a nucleon-nucleus interaction in which Fermi motion is included or on some type of cooperative model are examined. Other areas of interest involving pion production include tests of charge symmetry and pion multiplicities. (9 figures, 1 table) (U.S.)

  9. Photosensitized oxidation in the ocular lens: evidence for photosensitizers endogenous to the human lens

    International Nuclear Information System (INIS)

    Zigler, J.S. Jr.; Goosey, J.D.

    1981-01-01

    Numerous investigators have attempted to associate near UV light exposure with various changes which occur to lens crystallins during aging and cataractogenesis. Recently it was shown that in vitro singlet oxygen mediated oxidation of lens crystallins produces effects very similar to those documented for crystallins from old or cataractous lenses and it was suggested that near UV photodynamic effects may play a major role in vivo in aging in the human lens. It has now been shown that certain oxidation products of tryptophan which have been identified in human lens can act as near UV photosensitizers, producing singlet oxygen. The insoluble protein fraction from human cataracts was shown to have the capacity to act as a photosensitizer. An age-related increase in photosensitizing capacity was also demonstrated in the soluble crystallins from human lens. These findings are discussed with respect to development of pigmented nuclear cataracts. (author)

  10. Hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1981-01-01

    Qualitative picture of high energy hadron-nucleus collision process, emerging from the analysis of experimental data, is presented. Appropriate description procedure giving a possibility of reproducing various characteristics of this process in terms of the data on elementary hadron-nucleon interaction is proposed. Formula reproducing hadron-nucleus collision cross sections is derived. Inelastic collision cross sections for pion-nucleus and proton-nucleus reactions at wide energy interval are calculated for Pb, Ag, and Al targets. A-dependence of cross sections for pion-nucleus and proton-nucleus collisions at nearly 50 GeV/c momentum were calculated and compared with existing experimental data. Energy dependence of cross sections for hadron-nucleus collisions is determined simply by energy dependence of corresponding cross sections for hadron-nucleon collisions; A-dependence is determined simply by nuclear sizes and nucleon density distributions in nuclei

  11. Aberration design of zoom lens systems using thick lens modules.

    Science.gov (United States)

    Zhang, Jinkai; Chen, Xiaobo; Xi, Juntong; Wu, Zhuoqi

    2014-12-20

    A systematic approach for the aberration design of a zoom lens system using a thick lens module is presented. Each component is treated as a thick lens module at the beginning of the design. A thick lens module refers to a thick lens component with a real lens structure, like lens materials, lens curvatures, lens thicknesses, and lens interval distances. All nine third-order aberrations of a thick lens component are considered during the design. The relationship of component aberrations in different zoom positions can be approximated from the aberration shift. After minimizing the aberrations of the zoom lens system, the nine third-order aberrations of every lens component can be determined. Then the thick lens structure of every lens component can be determined after optimization according to their first-order properties and third-order aberration targets. After a third optimization for minimum practical third-order aberrations of a zoom lens system, the aberration design using the thick lens module is complete, which provides a practical zoom lens system with thick lens structures. A double-sided telecentric zoom lens system is designed using the thick lens module in this paper, which shows that this method is practical for zoom lens design.

  12. Nucleus-nucleus potential with repulsive core and elastic scattering. Part 1. Nucleus-nucleus interaction potential

    International Nuclear Information System (INIS)

    Davidovs'ka, O.Yi.; Denisov, V.Yu.; Nesterov, V.O.

    2010-01-01

    Various approaches for nucleus-nucleus interaction potential evaluation are discussed in details. It is shown that the antisymmetrization of nucleons belonging to different nuclei and the Pauli principle give the essential contribution into the nucleus-nucleus potential at distances, when nuclei are strongly overlapping, and lead to appearance of the repulsive core of nucleus nucleus interaction at small distances between nuclei.

  13. Antiproton production in nucleon-nucleus and nucleus-nucleus collisions at the CERN-SPS

    International Nuclear Information System (INIS)

    Kadija, K.; Schmitz, N.; Seyboth, P.

    1996-01-01

    A model for antiproton production in nucleon-nucleus and nucleus-nucleus collisions at 200 GeV per nucleon, based on the wounded nucleon model is developed. The predictions are compared to published nucleon-nucleus and sulphur-nucleus data. The results suggest the presence of similar antiproton production processes in nucleon-nucleus and nucleus-nucleus collisions near midrapidity. (orig.)

  14. K+-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    The K + -nucleus system is reviewed and comparison with data is made. The principal conclusions are that the theoretical uncertainties in relating the K + -nucleus interaction to the K + -nucleon interaction are very small and hence the positive kaon makes an excellent probe of the nucleus. It is suggested that this particle may be more sensitive to non-nucleonic degrees of freedom (especially quarks) than classical probes

  15. Can reliable values of Young's modulus be deduced from Fisher's (1971) spinning lens measurements?

    Science.gov (United States)

    Burd, H J; Wilde, G S; Judge, S J

    2006-04-01

    The current textbook view of the causes of presbyopia rests very largely on a series of experiments reported by R.F. Fisher some three decades ago, and in particular on the values of lens Young's modulus inferred from the deformation caused by spinning excised lenses about their optical axis (Fisher 1971) We studied the extent to which inferred values of Young's modulus are influenced by assumptions inherent in the mathematical procedures used by Fisher to interpret the test and we investigated several alternative interpretation methods. The results suggest that modelling assumptions inherent in Fisher's original method may have led to systematic errors in the determination of the Young's modulus of the cortex and nucleus. Fisher's conclusion that the cortex is stiffer than the nucleus, particularly in middle age, may be an artefact associated with these systematic errors. Moreover, none of the models we explored are able to account for Fisher's claim that the removal of the capsule has only a modest effect on the deformations induced in the spinning lens.

  16. Refractive neutron lens

    International Nuclear Information System (INIS)

    Petrov, P.V.; Kolchevsky, N.N.

    2013-01-01

    Model of the refractive neutron lens is proposed. System of N lenses acts as one thin lens with a complex refraction index n*. The maximum number N max of individual lenses for 'thick' neutron lens is calculated. Refractive neutron lens properties (resolution, focal depth) as function of resolution factor F 0 =ρbc/μ and depth of field factor dF 0 =λF 0 =λρbc/μ are calculated. It is shown that micro resolution of the refractive neutron optics is far from the wavelength in size and its open possibilities for progress in refractive neutron optics. (authors)

  17. Microscopic model of nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Harvey, B.G.

    1986-04-01

    The collision of two nuclei is treated as a collection of collisions between the nucleons of the projectile and those of the target nucleus. The primary projectile fragments contain only those nucleons that did not undergo a collision. The inclusive and coincidence cross sections result from the decay of the excited primary fragments. 15 refs., 5 figs

  18. Peripheral Defocus of the Monkey Crystalline Lens With Accommodation in a Lens Stretcher

    Science.gov (United States)

    Maceo Heilman, Bianca; Manns, Fabrice; Ruggeri, Marco; Ho, Arthur; Gonzalez, Alex; Rowaan, Cor; Bernal, Andres; Arrieta, Esdras; Parel, Jean-Marie

    2018-01-01

    Purpose To characterize the peripheral defocus of the monkey crystalline lens and its changes with accommodation. Methods Experiments were performed on 15 lenses from 11 cynomolgus monkey eyes (age: 3.8–12.4 years, postmortem time: 33.5 ± 15.3 hours). The tissue was mounted in a motorized lens stretcher to allow for measurements of the lens in the accommodated (unstretched) and unaccommodated (stretched) states. A custom-built combined laser ray tracing and optical coherence tomography system was used to measure the paraxial on-axis and off-axis lens power for delivery angles ranging from −20° to +20° (in air). For each delivery angle, peripheral defocus was quantified as the difference between paraxial off-axis and on-axis power. The peripheral defocus of the lens was compared in the unstretched and stretched states. Results On average, the paraxial on-axis lens power was 52.0 ± 3.4 D in the unstretched state and 32.5 ± 5.1 D in the stretched state. In both states, the lens power increased with increasing delivery angle. From 0° to +20°, the relative peripheral lens power increased by 10.7 ± 1.4 D in the unstretched state and 7.5 ± 1.6 D in the stretched state. The change in field curvature with accommodation was statistically significant (P lens has greater curvature or relative peripheral power. Conclusions The cynomolgus monkey lens has significant accommodation-dependent curvature of field, which suggests that the lens asserts a significant contribution to the peripheral optical performance of the eye that also varies with the state of accommodation.

  19. Lipid-protein interactions in plasma membranes of fiber cells isolated from the human eye lens.

    Science.gov (United States)

    Raguz, Marija; Mainali, Laxman; O'Brien, William J; Subczynski, Witold K

    2014-03-01

    The protein content in human lens membranes is extremely high, increases with age, and is higher in the nucleus as compared with the cortex, which should strongly affect the organization and properties of the lipid bilayer portion of intact membranes. To assess these effects, the intact cortical and nuclear fiber cell plasma membranes isolated from human lenses from 41- to 60-year-old donors were studied using electron paramagnetic resonance spin-labeling methods. Results were compared with those obtained for lens lipid membranes prepared from total lipid extracts from human eyes of the same age group [Mainali, L., Raguz, M., O'Brien, W. J., and Subczynski, W. K. (2013) Biochim. Biophys. Acta]. Differences were considered to be mainly due to the effect of membrane proteins. The lipid-bilayer portions of intact membranes were significantly less fluid than lipid bilayers of lens lipid membranes, prepared without proteins. The intact membranes were found to contain three distinct lipid environments termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain. However, the cholesterol bilayer domain, which was detected in cortical and nuclear lens lipid membranes, was not detected in intact membranes. The relative amounts of bulk and trapped lipids were evaluated. The amount of lipids in domains uniquely formed due to the presence of membrane proteins was greater in nuclear membranes than in cortical membranes. Thus, it is evident that the rigidity of nuclear membranes is greater than that of cortical membranes. Also the permeability coefficients for oxygen measured in domains of nuclear membranes were significantly lower than appropriate coefficients measured in cortical membranes. Relationships between the organization of lipids into lipid domains in fiber cells plasma membranes and the organization of membrane proteins are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Post-lens tear turbidity and visual quality after scleral lens wear.

    Science.gov (United States)

    Carracedo, Gonzalo; Serramito-Blanco, Maria; Martin-Gil, Alba; Wang, Zicheng; Rodriguez-Pomar, Candela; Pintor, Jesús

    2017-11-01

    The aim was to evaluate the turbidity and thickness of the post-lens tear layer and its effect on visual quality in patients with keratoconus after the beginning of lens wear and before lens removal at the end of eight hours. Twenty-six patients with keratoconus (aged 36.95 ± 8.95 years) participated voluntarily in the study. The sample was divided into two groups: patients with intrastromal corneal ring (ICRS group) and patients without ICRS (KC group). Distance visual acuity (VA), contrast sensitivity, pachymetry, post-lens tear layer height and post-lens tear layer turbidity (percentage area occupied and number of particles per mm 2 ) were evaluated with optical coherence tomography before and after wearing a scleral lens. A significant increase of turbidity was found in all groups assessed (p turbidity parameters with distance VA but no correlation between turbidity and post-lens tear layer thickness at the beginning was found (p > 0.05). A strong correlation in all groups between the post-lens tear layer at the beginning and differences of tear layer thickness between two measures was also found (p turbidity. © 2017 Optometry Australia.

  1. Nucleus Ruber of Actinopterygians.

    Science.gov (United States)

    Nakayama, Tomoya; Miyajima, Satoshi; Nishino, Hirotaka; Narita, Junya; Abe, Hideki; Yamamoto, Naoyuki

    2016-01-01

    Nucleus ruber is known as an important supraspinal center that controls forelimb movements in tetrapods, and the rubral homologue may serve similar functions in fishes (motor control of pectoral fin). However, two apparently different structures have been identified as 'nucleus ruber' in actinopterygians. One is nucleus ruber of Goldstein (1905) (NRg), and the other nucleus ruber of Nieuwenhuys and Pouwels (1983) (NRnp). It remains unclear whether one of these nuclei (or perhaps both) is homologous to tetrapod nucleus ruber. To resolve this issue from a phylogenetic point of view, we have investigated the distribution of tegmental neurons retrogradely labeled from the spinal cord in eight actinopterygian species. We also investigated the presence/absence of the two nuclei with Nissl- or Bodian-stained brain section series of an additional 28 actinopterygian species by comparing the morphological features of candidate rubral neurons with those of neurons revealed by the tracer studies. Based on these analyses, the NRg was identified in all actinopterygians investigated in the present study, while the NRnp appears to be absent in basal actinopterygians. The phylogenetic distribution pattern indicates that the NRg is the more likely homologue of nucleus ruber, and the NRnp may be a derived nucleus that emerged during the course of actinopterygian evolution. © 2016 S. Karger AG, Basel.

  2. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    DEFF Research Database (Denmark)

    Kjeldsen, Henrik; Heinemeier, Jan; Heegaard, Steffen

    2010-01-01

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth...

  3. Meta-analysis comparing same-day versus delayedvitrectomy clinical outcomes for intravitreal retained lens fragments after age-relatedcataract surgery

    Directory of Open Access Journals (Sweden)

    Vanner EA

    2014-11-01

    Full Text Available Elizabeth A Vanner,1 Michael W Stewart21Department of Preventive Medicine, Pathology and Bioinformatics, Stony Brook University, Stony Brook, NY, USA; 2Department of Ophthalmology, Mayo Clinic College of Medicine, Jacksonville, FL, USAPurpose/design: We aimed to perform a systematic review and meta-analysis comparing the risk difference of clinical outcomes for same-day (SD vs delayed (DEL pars plana vitrectomy (PPV.Methods: We searched MEDLINE (English; January 1, 1985 to July 16, 2013 and article reference lists, for patients with crystalline retained lens fragments and discussion of SD-PPV vs DEL-PPV. For the meta-analysis, articles needed the number of patients receiving SD-PPV and DEL-PPV, and the number, in each group, who experienced one or more of the outcomes: not good visual acuity (VA (<20/40, bad VA (≤20/200, retinal detachment, increased intraocular pressure/glaucoma, intraocular infection/inflammation, cystoid macular edema, and corneal edema.Results: Of 304 articles identified, 23 provided data for the meta-analysis. Results were mixed, indicating 1 neither vitrectomy time produced better outcomes in all studies (not good VA risk difference =10.3% [positive numbers favored SD-PPV; negative numbers favored DEL-PPV], 95% confidence interval [CI] = [-0.4% to 21.0%], P=0.059; and bad VA risk difference =-0.3%, 95% CI = [-10.7% to 10.1%], P=0.953; 2 better outcomes with immediate SD-PPV compared with all DEL-PPV (not good VA risk difference =16.2%, 95% CI = [0.8% to 31.5%], P=0.039; and bad VA risk difference =8.5%; 95% CI = [0.8% to 16.2%], P=0.030; and 3 immediate SD-PPV and prompt DEL-PPV (3 to 14 days after cataract surgery had no significant differences and so may produce similar outcomes (not good VA risk differences range = [-19.9% to 6.5%], 95% CI = [-59.9% to 36.4%]; and bad VA risk differences range = [-6.9% to 7.4%], 95% CI = [-33.1% to 31.8%].Conclusion: Perhaps SD-PPV should be limited to facilities at which a

  4. Capsular 'pits' in the human lens.

    OpenAIRE

    Harris, M. L.; Brown, N. A.; Shun-Shin, G. A.; Smith, G. T.

    1992-01-01

    The lens capsule is an atypical basement membrane surrounding the lens epithelial cells and lens fibres which make up the remainder of the human lens. A seemingly unreported morphological change visible in the lens capsule with the biomicroscope is described.

  5. Changes in monkey crystalline lens spherical aberration during simulated accommodation in a lens stretcher.

    Science.gov (United States)

    Maceo Heilman, Bianca; Manns, Fabrice; de Castro, Alberto; Durkee, Heather; Arrieta, Esdras; Marcos, Susana; Parel, Jean-Marie

    2015-02-10

    The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5 ± 13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. The unstretched lens power decreased with age from 59.3 ± 4.0 diopters (D) for young lenses to 45.7 ± 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3 ± 0.7 μm for young lenses to -5.0 ± 0.5 μm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5 ± 3.4 D and -2.6 ± 0.5 μm, respectively. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  6. Diffractive ''semioptical'' model for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Musulmanbekov, Zh.Zh.

    1979-01-01

    Diffraction Glauber theory for nucleus-nucleus collisions is considered in approximation when the initial nucleus interacts as a whole with nucleons of the target nucleus. Such an approach, being intermediate between precise Glauber theory and its optical limit, essentially simplifies numerical calculations and gives a good agreement with experiments as well. (author)

  7. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  8. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  9. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

  10. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

  11. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses ...

  12. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her ...

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... contacto de color Sep. 26, 2013 It started as an impulsive buy from a souvenir shop, but ... require the same level of care or consideration as a standard contact lens because they can be ...

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... With Proper Contact Lens Care Apr 23, 2018 Solar Eclipse Inflicts Damage in the Shape of the ... edging closer, thanks to a wave of new technologies aiming to fix failing eye parts with human- ...

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... glow-in-the-dark lizard lenses, costume contacts can certainly add a spooky, eye-popping touch. But ... consideration as a standard contact lens because they can be purchased over-the-counter or on the ...

  16. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... valid prescription that includes the brand name, lens measurements, and expiration date. Purchase the colored contact lenses ... with human-made versions. U.S. News Highlights the Value of Ophthalmologists APR 20, 2018 By Dan T. ...

  17. Vortex gas lens

    Science.gov (United States)

    Bogdanoff, David W.; Berschauer, Andrew; Parker, Timothy W.; Vickers, Jesse E.

    1989-01-01

    A vortex gas lens concept is presented. Such a lens has a potential power density capability of 10 to the 9th - 10 to the 10th w/sq cm. An experimental prototype was constructed, and the divergence half angle of the exiting beam was measured as a function of the lens operating parameters. Reasonably good agreement is found between the experimental results and theoretical calculations. The expanded beam was observed to be steady, and no strong, potentially beam-degrading jets were found to issue from the ends of the lens. Estimates of random beam deflection angles to be expected due to boundary layer noise are presented; these angles are very small.

  18. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... had not been properly fitted by an eye care professional, the lenses stuck to my eye like ... lenses do not require the same level of care or consideration as a standard contact lens because ...

  19. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... sell contacts without a prescription are breaking the law, and may be fined $11,000 per violation. " ...

  20. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not require the same level of care or consideration as a standard contact lens because they can ... Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms ...

  1. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... ask for a prescription. There is no such thing as a "one size fits all" contact lens. ...

  2. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. Follow the contact lens care directions for cleaning, disinfecting, and wearing the lenses. Never share contact ... with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job Center © American ...

  3. Lens autofluorescence is not increased at high altitude

    DEFF Research Database (Denmark)

    Kessel, Line; Kofoed, Peter Kristian; Zubieta-Calleja, Gustavo

    2010-01-01

    in Denmark. RESULTS: No significant differences in lens fluorescence or transmittance were found between Bolivian and Danish volunteers. CONCLUSION: Age-corrected lens fluorescence and transmittance were comparable for healthy participants living at high altitude near the equator and healthy volunteers...

  4. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, Henrik, E-mail: kjeldsen@phys.au.d [AMS 14C Dating Centre, Department of Physics and Astronomy, University of Aarhus, Aarhus (Denmark); Heinemeier, Jan [AMS 14C Dating Centre, Department of Physics and Astronomy, University of Aarhus, Aarhus (Denmark); Heegaard, Steffen [Eye Pathology Section, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen (Denmark); Jacobsen, Christina; Lynnerup, Niels [Department of Forensic Medicine, University of Copenhagen, Copenhagen (Denmark)

    2010-04-15

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth, in accordance with expectations. Moreover, it has been possible to develop an age model for the formation of the eye-lens crystallines. From this model a radiocarbon calibration curve for lens crystallines has been calculated. As a consequence, the time of birth of humans can be determined with an accuracy of a few years by radiocarbon dating.

  5. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    International Nuclear Information System (INIS)

    Kjeldsen, Henrik; Heinemeier, Jan; Heegaard, Steffen; Jacobsen, Christina; Lynnerup, Niels

    2010-01-01

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth, in accordance with expectations. Moreover, it has been possible to develop an age model for the formation of the eye-lens crystallines. From this model a radiocarbon calibration curve for lens crystallines has been calculated. As a consequence, the time of birth of humans can be determined with an accuracy of a few years by radiocarbon dating.

  6. Dissipation in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Santanu Pal

    1984-01-01

    This paper deals with the mechanism of one- and two-body dissipations in nucleus-nucleus collisions. The average energy transferred to nuclear excitations is calculated using a time-dependent density matrix approach with lowest-order approximations. Considering the nuclei as Fermi gases, and using a gaussian-type NN interaction as the basic perturbation, simplified expressions are obtained for energy dissipations. These expressions are quite instructive to follow a number of interesting aspects of one- and two-body dissipations. It is theoretically observed that the memory time for the two-body dissipation is significantly smaller than that of one-body dissipation. A threshold-type dependence of the transferred energy on the relative velocity between the two nuclei is also observed. This threshold velocity is found to be related with the intrinsic nucleon kinetic energy for two-body dissipation and with the nuclear size for the one-body case. This observation further suggests that the total dissipated energy is shared between the two nuclei approximately in the ratio of their masses. The physical origin of these observations is also explained. Numerical calculations further illustrate some characteristic features of one- and two-body dissipations. (orig.)

  7. High energy nucleus-nucleus scattering and matter radius of unstable nucleus

    International Nuclear Information System (INIS)

    Sato, H.; Okuhara, Y.

    1985-07-01

    The interaction cross sections of high energy nucleus-nucleus scattering have been studied with the Glauber Model and Hartree-Fock like variational calculation for the nuclear structure. It is found that the experimental interaction cross sections of the light unstable nucleus-stable nucleus scatterings measured by INS-LBL collaboration are well reproduceable. (author)

  8. Particle correlations in proton-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Nagamiya, Sh.

    1981-01-01

    Particle correlations in proton-nucleus and nucleus-nucleus collisions at energies of 1-2 GeV/nucleon are investigated. The problems of measurement of the mean free path lambda of protons inside the nucleus and the interaction radius of nucleus-nucleus collisions is considered. The value of lambda has been determined in two-proton coincidence experiment in proton-nucleus interaction at 800 MeV. The observed value of lambda is slightly longer than the expected from free nucleon-nucleon collisions. Some preliminary results on proton emission beyond free nucleon-nucleon kinemaics are given

  9. Primary intraocular lens implantation for penetrating lens trauma in Africa.

    Science.gov (United States)

    Bowman, R J; Yorston, D; Wood, M; Gilbert, C; Foster, A

    1998-09-01

    This study aimed to audit the surgical strategy of primary posterior chamber intraocular lens implantation for cases of recent penetrating trauma involving the lens in an African population. Retrospective, noncomparative case series. Seventy-two cases are reported, including all patients who underwent primary intraocular lens implantation for traumatic cataract extraction performed within 1 month of injury between 1988 and 1996. Demographic characteristics and follow-up attendance rates are analyzed. Surgical technique and the occurrence of intraoperative and postoperative complications are reported. Visual outcomes are reported with detailed analysis for cases of poor visual outcome. Mean age was 14.3 years (standard deviation = 11.1), 57 (79%) were male and 15 (21%) were female (chi-square = 23.66, P capsule had been breached by the trauma in 27 (38%) cases, and 15 of these required anterior vitrectomy. Capsular fixation of the implant was achieved in 49% of patients, the remainder having sulcus fixation. Intraoperative rupture of the posterior capsule occurred in four cases. The only common postoperative complication was acute fibrinous anterior uveitis, which occurred in 29 (40%) patients, and 32% of patients followed up for at least 6 months required secondary posterior capsulotomy. This was more common in younger patients (chi-square = 4.2, P < 0.05). Corrected postoperative visual acuities were available for 51 patients, of which 71% achieved 20/60 or better visual acuity. Patients 6 years of age or younger were less likely to achieve 20/60 (chi-square = 6.61, P = 0.01). This surgical strategy has proved successful, producing good visual results and causing no sight-threatening complications. Primary posterior capsulotomy may be appropriate for younger patients.

  10. [Analysis of the Effect of Non-phacoemulsification Cataract Operation on Corneal Endothelial Cell Nucleus Division].

    Science.gov (United States)

    Huang, Zufeng; Miao, Xiaoqing

    2015-09-01

    To investigate the effect of non-phacoemulsification cataract operation in two different patterns of nucleus delivery on the quantity and morphology of corneal endothelial cells and postoperative visual acuity. Forty patients diagnosed with cataract underwent cataract surgery and were assigned into the direct nuclear delivery and semi-nuclear delivery groups. Lens density was measured and divided into the hard and soft lenses according to Emery-little lens nucleus grading system. Non-phacoemulsification cataract operation was performed. At 3 d after surgery, the quantity and morphology of corneal endothelium were counted and observed under corneal endothelial microscope. During 3-month postoperative follow-up, the endothelial cell loss rate, morphological changes and visual acuity were compared among four groups. Corneal endothelial cell loss rate in the direct delivery of hard nucleus group significantly differed from those in the other three groups before and 3 months after operation (P nucleus, semi-delivery of hard nucleus and semi-delivery soft nucleus groups (all P > 0.05). Preoperative and postoperative 2-d visual acuity did not differ between the semi-delivery of hard nucleus and direct delivery of soft nucleus groups (P = 0.49), significantly differed from those in the semi-delivery of soft nucleus (P = 0.03) and direct delivery of hard nucleus groups (P = 0.14). Visual acuity at postoperative four months did not differ among four groups (P = 0.067). During non-phacoemulsification cataract surgery, direct delivery of hard nucleus caused severe injury to corneal endothelium and semi-delivery of soft nucleus yielded mild corneal endothelial injury. Slight corneal endothelial injury exerted no apparent effect upon visual acuity and corneal endothelial morphology at three months after surgery.

  11. Some experimental results of the investigation of hadron-nucleus and nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Azimov, S.A.; Gulamov, K.G.; Chernov, G.M.

    1978-01-01

    Recent experimental data on the hadron-nucleus and nucleus-nucleus inelastic interactions are analyzed. A particular attention is paid to the description of the leading hadron spectra and of the spectra of nucleon recoils in hadron-nucleus interactions. Some of the results of the experimental studies of correlations between secondary particles are discussed. This discussion demonstrates that an analysis of the multiparticle phenomena is very promising regarding the discrimination between the different models for the hadron-nucleus and nucleus-nucleus interactions. It is pointed out that the actual mechanism of the hadron-nucleus and nucleus-nucleus interactions is a rather complex one and can be described comprehensively by none of the existing models

  12. Relationship between lens density measurements by Pentacam Scheimpflug imaging and torsional phacoemulsification parameters

    Directory of Open Access Journals (Sweden)

    Suleyman Demircan

    2014-10-01

    Full Text Available AIM: To evaluate the relationship between the density values of the lens nucleus measured using Pentacam Scheimpflug imaging and torsional phacoemulsification dynamics such as the level of ultrasound energy, as well as the duration and amount of fluid used in patients with age-related nuclear cataract. METHODS: This was a prospective observer-masked study. Pentacam Scheimpflug imaging was performed following pupil dilation. The cataracts were automatically graded from 1 to 5 using pentacam nucleus densitometry(PND, also known as Pentacam nucleus staging(PNSsoftware by the same observer. After phacoemulsification, total Ultrasound(U/Stime, Cumulative dissipated energy(CDE, Torsional U/S time, and Estimated fluid use were automatically calculated and displayed on the monitor of Infiniti OZiL IP phacoemulsification system. One-way analysis of variance(ANOVAwas used to assess differences between groups. The Tamhane test was used for multiple group analysis. Spearman correlation analysis was used to assess the relationship between lens density measured by PND and the dynamics of torsional phacoemulsification. P0.05 was considered statistically significant. RESULTS:In the present study, 125 eyes from 125 patients were evaluated. Mean age was 69.7±9.4y(range: 48-88y, and 61 men and 64 women were included. The highest and lowest values of U/S total time, torsional U/S time, CDE, and Estimated fluid use were 0.70 - 158.90s, 0.70-158.50s, 0.11-42.65, and 21-98 mL in groups, respectively. Significant differences were found among PND groups. When the relationship between phacoemulsification dynamics and PND values were evaluated, there were significant correlations between PND value and total ultrasound time(r=0.767; Pr=0.767; Pr=0.758; Pr=0.602; PCONCLUSION:An objective degree of nucleus density obtained by PND scoring before cataract surgery may allow antecedent determination of intraoperative phacoemulsification parameters. Thus, individualized

  13. Integration of gene expression profiling of hypothalamic arcuate nucleus with genome-wide associations to discover functional variants associated with age at puberty in gilts

    Science.gov (United States)

    Age at puberty (AP) in gilts is a moderately heritable trait (h2 = 0.37) and the earliest indicator of sow reproductive longevity. Therefore, quantifying the pleiotropic sources that influence both AP and reproductive longevity is important in understanding the differences in sow fertility. In this ...

  14. Multifragmentation in peripheral nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Trautmann, W.; Adloff, J.C.; Bouissou, P.; Hubele, J.; Imme, G.; Iori, I.; Kreutz, P.; Leray, S.; Lindenstruth, V.; Liu, Z.; Lynen, U.; Meijer, R.J.; Milkau, U.; Moroni, A.; Mueller, W.F.J.; Ngo, C.; Ogilvie, C.A.; Pochodzalla, J.; Raciti, G.; Rudolf, G.; Schuettauf, A.; Stuttge, L.

    1993-10-01

    The complete fragmentation of highly excited nuclear systems into fragments of intermediate mass is observed in heavy-ion reactions at relativistic bombarding energies in the range of several hundreds of MeV per nucleon. Similar features are found for peripheral collisions between heavy nuclei and for more central collisions between a heavy and a light nucleus. The partition space explored in multifragment decays is well described by the statistical multifragmentation models. The expansion before breakup is confirmed by the analysis of the measured fragment energies of ternary events in their own rest frame. Collective radial flow is confined to rather small values in these peripheral-type reactions. Many conceptually different models seem to be capable of reproducing the charge correlations measured for the multifragment decays. (orig.)

  15. Notochord to Nucleus Pulposus Transition.

    Science.gov (United States)

    Lawson, Lisa; Harfe, Brian D

    2015-10-01

    A tissue that commonly deteriorates in older vertebrates is the intervertebral disc, which is located between the vertebrae. Age-related changes in the intervertebral discs are thought to cause most cases of back pain. Back pain affects more than half of people over the age of 65, and the treatment of back pain costs 50-100 billion dollars per year in the USA. The normal intervertebral disc is composed of three distinct regions: a thick outer ring of fibrous cartilage called the annulus fibrosus, a gel-like material that is surrounded by the annulus fibrosus called the nucleus pulposus, and superior and inferior cartilaginous end plates. The nucleus pulposus has been shown to be critical for disc health and function. Damage to this structure often leads to disc disease. Recent reports have demonstrated that the embryonic notochord, a rod-like structure present in the midline of vertebrate embryos, gives rise to all cell types found in adult nuclei pulposi. The mechanism responsible for the transformation of the notochord into nuclei pulposi is unknown. In this review, we discuss potential molecular and physical mechanisms that may be responsible for the notochord to nuclei pulposi transition.

  16. Antiproton-nucleus interaction

    International Nuclear Information System (INIS)

    Gibbs, W.R.

    1984-01-01

    Several facets of antinucleon-nucleus interactions are explored. The topics treated are: coherent interactions, production of unusual states and particles in the nuclear medium, and the creation of extreme states of matter by antimatter annihilation. It is found that temperatures of the magnitude necessary to achieve the predicted quark-gluon phase transition are obtained. 20 references

  17. Nucleus accumbens and impulsivity

    NARCIS (Netherlands)

    Basar, K.; Sesia, T.; Groenewegen, H.J.; Steinbusch, H.W.; Visser-vandewalle, V.; Temel, Y.

    2010-01-01

    The multifaceted concept of impulsivity implies that different impulsivity aspects, mediated by different neural processes, influence behavior at different levels. The nucleus accumbens (NAc) is a key component of the neural processes regulating impulsivity. In this review, we discuss the findings

  18. Quasi-elastic shadowing in nucleus-nucleus elastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Dymarz, R; Malecki, A [Institute of Nuclear Physics, Krakow (Poland); Gluski, K [Institute of Nuclear Research, Warsaw (Poland); Picchi, P [Turin Univ. (Italy). Ist. di Fisica; Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica)

    1979-01-06

    The complete evaluation of the Glauber multiple-scattering series for nucleus-nucleus collisions is a very difficult task and that is why various approximate formulae were proposed. In this work some of these approximations are discussed.

  19. Mechanisms of High Energy Hadron-Nucleus and Nucleus-Nucleus Collision Processes

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1994-01-01

    Mechanisms of high energy hadron-nucleus and nucleus-nucleus collision processes are depicted qualitatively, as prompted experimentally. In hadron-nucleus collisions the interaction of the incident hadron in intranuclear matter is localized in small cylindrical volume, with the radius as large as the strong interaction range is, centered on the hadron course in the nucleus. The nucleon emission is induced by the hadron in its passing through the nucleus; particles are produced via intermediate objects produced in 2 → 2 endoergic reactions of the hadron and its successors with downstream nucleons. In nucleus-nucleus collisions, the outcome of the reaction appears as the composition of statistically independent hadron-nucleus collision outcomes at various impact parameters. Observable effects supporting such mechanisms are discussed. 51 refs

  20. Effect of contact lens use on Computer Vision Syndrome.

    Science.gov (United States)

    Tauste, Ana; Ronda, Elena; Molina, María-José; Seguí, Mar

    2016-03-01

    To analyse the relationship between Computer Vision Syndrome (CVS) in computer workers and contact lens use, according to lens materials. Cross-sectional study. The study included 426 civil-service office workers, of whom 22% were contact lens wearers. Workers completed the Computer Vision Syndrome Questionnaire (CVS-Q) and provided information on their contact lenses and exposure to video display terminals (VDT) at work. CVS was defined as a CVS-Q score of 6 or more. The covariates were age and sex. Logistic regression was used to calculate the association (crude and adjusted for age and sex) between CVS and individual and work-related factors, and between CVS and contact lens type. Contact lens wearers are more likely to suffer CVS than non-lens wearers, with a prevalence of 65% vs 50%. Workers who wear contact lenses and are exposed to the computer for more than 6 h day(-1) are more likely to suffer CVS than non-lens wearers working at the computer for the same amount of time (aOR = 4.85; 95% CI, 1.25-18.80; p = 0.02). Regular contact lens use increases CVS after 6 h of computer work. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  1. N-epsilon-(carboxyethyl)lysine, a product of the chemical modification of proteins by methylglyoxal, increases with age in human lens proteins.

    OpenAIRE

    Ahmed, M U; Brinkmann Frye, E; Degenhardt, T P; Thorpe, S R; Baynes, J W

    1997-01-01

    Advanced glycation end-products and glycoxidation products, such as Nepsilon-(carboxymethyl)lysine (CML) and pentosidine, accumulate in long-lived tissue proteins with age and are implicated in the aging of tissue proteins and in the development of pathology in diabetes, atherosclerosis and other diseases. In this paper we describe a new advanced glycation end-product, Nepsilon-(carboxyethyl)lysine (CEL), which is formed during the reaction of methylglyoxal with lysine residues in model compo...

  2. Symmetric lens with extended depth of focus

    OpenAIRE

    Cho, Sung Nae

    2008-01-01

    The lens surface profile is derived based on the instantaneous focal length versus the lens radius data. The lens design based on instantaneous focal length versus the lens radius data has many useful applications in software assisted image focusing technology.

  3. A catoptric lens

    International Nuclear Information System (INIS)

    Rambauske, W.R.

    1973-01-01

    The invention relates to a catoptric lens for combining energies transmitted by several sources such as lasers; said lens comprising mirrors, the reflective surfaces of which have their focuses spaced from a common axis of symmetry. By means of these reflecting surfaces, which are generated by the nutation of portions of quadratic conics about the axis of symmetry, it is possible to focus the energy emmited by several lasers at the focus of the exit-mirror reflecting surface. This can be applied to thermonuclear fusion [fr

  4. Study of Relativistic Nucleus - Nucleus Collisions

    CERN Multimedia

    2002-01-01

    The aim of the experiment is to survey the reaction mechanisms involved in the collision of 60~GeV/nucleon and 200~GeV/nucleon light ions ($^{16}$0 and $^{32}$S provided by a new GSI-LBL injector) with different nuclei, to determine the stopping power of nuclear matter and to search for evidence of the formation of quark matter by comparison to hadron-nucleus reactions at the same incident energies. \\\\ The experimental set-up consists of a 2 m Streamer Chamber in the Vertex Magnet used to detect all the charged particles emerging from the interaction as well as the neutral strange particles that decay inside the chamber. The high energy of the forward-going particles are detected by four sets of calorimeters. A highly segmented Photon Position Detector (PPD) backed up by a 240 segment Ring Calorimeter will cover one unit of rapidity around mid-rapidity. An Intermediate Calorimeter will cover the rest of the forward phase space except for the region around beam rapidity, where a Veto Calorimeter will detect be...

  5. Transglutaminase involvement in UV-A damage to the eye lens

    International Nuclear Information System (INIS)

    Weinreb, Orly; Dovrat, A.

    1996-01-01

    Solar radiation is believed to be one of the major environmental factors involved in lens cataractogenesis. The purpose of the study was to investigate the mechanisms by which UV-A at 365 nm causes damage to the eye lens. Bovine lenses were placed in special culture cells for pre-incubation of 24 hr. The lenses were positioned so that the anterior surface faced the incident UV-A radiation source and were maintained in the cells during irradiation. After irradiation, lens optical quality was monitored throughout the culture period and lens epithelium, cortex and nuclear samples were taken for biochemical analysis. Transglutaminase activity in the lens was affected by the radiation. The activity of transglutaminase in lens epithelium cortex and nucleus increased as a result of the irradiation and then declined towards control levels during the culture period, as the lens recovered from the UV-A damage. Specific lens proteins αB and βB1 crystallins (the enzyme substrates) were analyzed by SDS polyacrylamid gel electrophoreses and immunoblotting with specific antibodies. Seventy-two hours after irradiation of 44.8 J cm -2 UV-A, αB crystallins were affected as was shown by the appearance of aggregation and degradation products. Some protein changes seem to be reversible. It appears that transglutaminase may be involved in the mechanism by which UV-A causes damage to the eye lens. (Author)

  6. A Tribute to Len Barton

    Science.gov (United States)

    Tomlinson, Sally

    2010-01-01

    This article constitutes a short personal tribute to Len Barton in honour of his work and our collegial relationship going back over 30 years. It covers how Len saw his intellectual project of providing critical sociological and political perspectives on special education, disability and inclusion, and his own radical political perspectives. Len's…

  7. Luneburg lens in silicon photonics.

    Science.gov (United States)

    Di Falco, Andrea; Kehr, Susanne C; Leonhardt, Ulf

    2011-03-14

    The Luneburg lens is an aberration-free lens that focuses light from all directions equally well. We fabricated and tested a Luneburg lens in silicon photonics. Such fully-integrated lenses may become the building blocks of compact Fourier optics on chips. Furthermore, our fabrication technique is sufficiently versatile for making perfect imaging devices on silicon platforms.

  8. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. There is no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Even if you have perfect vision, you need to get an eye exam and a prescription ...

  9. Contact Lens Risks

    Science.gov (United States)

    ... There is a risk of eye infection from bacteria in swimming pool water, hot tubs, lakes and the ocean Replace your contact lens storage case every 3 months or as directed by your eye care professional. Other Risks of Contact Lenses Other risks of contact lenses include pink eye ( ...

  10. MISSING: BUBBLE CHAMBER LENS

    CERN Multimedia

    2001-01-01

    Would the person who borrowed the large bubble chamber lens from the Microcosm workshops on the ISR please return it. This is a much used piece from our object archives. If anybody has any information about the whereabouts of this object, please contact Emma.Sanders@cern.ch Thank you

  11. The Lens of Chemistry

    Science.gov (United States)

    Thalos, Mariam

    2013-01-01

    Chemistry possesses a distinctive theoretical lens--a distinctive set of theoretical concerns regarding the dynamics and transformations of a perplexing variety of organic and nonorganic substances--to which it must be faithful. Even if it is true that chemical facts bear a special (reductive) relationship to physical facts, nonetheless it will…

  12. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... wear any kind of contact lens. In Butler's case, the lenses caused an infection and left her with a corneal ... A recent article from U.S. News and World Report explains what ophthalmologists are and how they can ...

  13. Quadrupole magnetic lens

    International Nuclear Information System (INIS)

    Piskunov, V.A.

    1981-01-01

    The following connection of windings of electromagnet is suggested for simplification of the design of qUadrupole magnetic lens intended for use in radiotechnical and electron-optical devices. The mentioned windings are connected with each other by a bridge scheme and the variable resistors are switched in its diagonals in the lens containing four electromagnet with windings connected with two variable resistors the mobile contacts of which are connected with a direct current source. Current redistribution between left windings and right windings takes place at shift of mobile contact of variable resistor, and current redistribution between upper and low coils of electromagnets takes place at shifting mobile contact of the other variable resistor. In this case smooth and independent electron-optical misalignment of lens by two mutually perpendicular directions proceeds. Use of the given design of the lens in the oscillograph permits to use printing assembly for alignment plate and to reduce the number of connections at the expense of decreasing the number of resistors

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... can be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... ask for a prescription. There is no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted may scratch the eye or cause blood vessels to grow into ...

  15. Interacting gluon model for hadron-nucleus and nucleus-nucleus collisions in the central rapidity region

    International Nuclear Information System (INIS)

    Fowler, G.N.; Navarra, F.S.; Plumer, M.; Lawrence Berkeley Laboratory, Nuclear Science Division, Berkeley, California 94720); Vourdas, A.; Weiner, R.M.

    1989-01-01

    The interacting gluon model developed to describe the inelasticity distribution in hadron-nucleon collisions has been generalized and applied to hadron-nucleus and nucleus-nucleus interactions. Leading particle spectra and energy distributions in hadron-nucleus and nucleus-nucleus collisions are calculated

  16. [Intraocular lens implantation with one loop haptic amputated: a new propose to the subluxation lens surgical treatment].

    Science.gov (United States)

    Ventura, Marcelo; Endriss, Daniela

    2010-01-01

    To evaluate the postoperative results of congenital lens subluxation corrected by a new technique. Retrospective chart review of 21 eyes of 13 patients with no traumatic lens subluxation who underwent surgery in Altino Ventura Foundation from April, 1999 to April, 2004. The mean age was 8.7 +/- 5.4 years old, and the mean follow-up period was 21.5 +/- 19.3 months. Patients underwent phacoaspiration, endocapsular ring and intraocular lens (IOL) implantation. The implanted IOL had one loop haptic excised and was supported above the ring, inside the capsular bag promoting intraocular lens centralization. Visual acuity improvement was observed in all cases. There was a significant reduction of the spherical equivalent and spherical component comparing the pre and postoperative refraction (psubluxation surgical treatment, promoting lens centralization and postoperative visual acuity improvement.

  17. The Role of Aquaporins in Ocular Lens Homeostasis

    Science.gov (United States)

    Schey, Kevin L.; Petrova, Rosica S.; Gletten, Romell B.; Donaldson, Paul J.

    2017-01-01

    Aquaporins (AQPs), by playing essential roles in the maintenance of ocular lens homeostasis, contribute to the establishment and maintenance of the overall optical properties of the lens over many decades of life. Three aquaporins, AQP0, AQP1 and AQP5, each with distinctly different functional properties, are abundantly and differentially expressed in the different regions of the ocular lens. Furthermore, the diversity of AQP functionality is increased in the absence of protein turnover by age-related modifications to lens AQPs that are proposed to alter AQP function in the different regions of the lens. These regional differences in AQP functionality are proposed to contribute to the generation and directionality of the lens internal microcirculation; a system of circulating ionic and fluid fluxes that delivers nutrients to and removes wastes from the lens faster than could be achieved by passive diffusion alone. In this review, we present how regional differences in lens AQP isoforms potentially contribute to this microcirculation system by highlighting current areas of investigation and emphasizing areas where future work is required. PMID:29231874

  18. Nucleus-nucleus collision as superposition of nucleon-nucleus collisions

    International Nuclear Information System (INIS)

    Orlova, G.I.; Adamovich, M.I.; Aggarwal, M.M.

    1999-01-01

    Angular distributions of charged particles produced in 16 O and 32 S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b NA , that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus. (orig.)

  19. Nucleus-Nucleus Collision as Superposition of Nucleon-Nucleus Collisions

    International Nuclear Information System (INIS)

    Orlova, G.I.; Adamovich, M.I.; Aggarwal, M.M.; Alexandrov, Y.A.; Andreeva, N.P.; Badyal, S.K.; Basova, E.S.; Bhalla, K.B.; Bhasin, A.; Bhatia, V.S.; Bradnova, V.; Bubnov, V.I.; Cai, X.; Chasnikov, I.Y.; Chen, G.M.; Chernova, L.P.; Chernyavsky, M.M.; Dhamija, S.; Chenawi, K.El; Felea, D.; Feng, S.Q.; Gaitinov, A.S.; Ganssauge, E.R.; Garpman, S.; Gerassimov, S.G.; Gheata, A.; Gheata, M.; Grote, J.; Gulamov, K.G.; Gupta, S.K.; Gupta, V.K.; Henjes, U.; Jakobsson, B.; Kanygina, E.K.; Karabova, M.; Kharlamov, S.P.; Kovalenko, A.D.; Krasnov, S.A.; Kumar, V.; Larionova, V.G.; Li, Y.X.; Liu, L.S.; Lokanathan, S.; Lord, J.J.; Lukicheva, N.S.; Lu, Y.; Luo, S.B.; Mangotra, L.K.; Manhas, I.; Mittra, I.S.; Musaeva, A.K.; Nasyrov, S.Z.; Navotny, V.S.; Nystrand, J.; Otterlund, I.; Peresadko, N.G.; Qian, W.Y.; Qin, Y.M.; Raniwala, R.; Rao, N.K.; Roeper, M.; Rusakova, V.V.; Saidkhanov, N.; Salmanova, N.A.; Seitimbetov, A.M.; Sethi, R.; Singh, B.; Skelding, D.; Soderstrem, K.; Stenlund, E.; Svechnikova, L.N.; Svensson, T.; Tawfik, A.M.; Tothova, M.; Tretyakova, M.I.; Trofimova, T.P.; Tuleeva, U.I.; Vashisht, Vani; Vokal, S.; Vrlakova, J.; Wang, H.Q.; Wang, X.R.; Weng, Z.Q.; Wilkes, R.J.; Yang, C.B.; Yin, Z.B.; Yu, L.Z.; Zhang, D.H.; Zheng, P.Y.; Zhokhova, S.I.; Zhou, D.C.

    1999-01-01

    Angular distributions of charged particles produced in 16 O and 32 S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b NA , that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus

  20. Nucleus-Nucleus Collision as Superposition of Nucleon-Nucleus Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Orlova, G I; Adamovich, M I; Aggarwal, M M; Alexandrov, Y A; Andreeva, N P; Badyal, S K; Basova, E S; Bhalla, K B; Bhasin, A; Bhatia, V S; Bradnova, V; Bubnov, V I; Cai, X; Chasnikov, I Y; Chen, G M; Chernova, L P; Chernyavsky, M M; Dhamija, S; Chenawi, K El; Felea, D; Feng, S Q; Gaitinov, A S; Ganssauge, E R; Garpman, S; Gerassimov, S G; Gheata, A; Gheata, M; Grote, J; Gulamov, K G; Gupta, S K; Gupta, V K; Henjes, U; Jakobsson, B; Kanygina, E K; Karabova, M; Kharlamov, S P; Kovalenko, A D; Krasnov, S A; Kumar, V; Larionova, V G; Li, Y X; Liu, L S; Lokanathan, S; Lord, J J; Lukicheva, N S; Lu, Y; Luo, S B; Mangotra, L K; Manhas, I; Mittra, I S; Musaeva, A K; Nasyrov, S Z; Navotny, V S; Nystrand, J; Otterlund, I; Peresadko, N G; Qian, W Y; Qin, Y M; Raniwala, R; Rao, N K; Roeper, M; Rusakova, V V; Saidkhanov, N; Salmanova, N A; Seitimbetov, A M; Sethi, R; Singh, B; Skelding, D; Soderstrem, K; Stenlund, E; Svechnikova, L N; Svensson, T; Tawfik, A M; Tothova, M; Tretyakova, M I; Trofimova, T P; Tuleeva, U I; Vashisht, Vani; Vokal, S; Vrlakova, J; Wang, H Q; Wang, X R; Weng, Z Q; Wilkes, R J; Yang, C B; Yin, Z B; Yu, L Z; Zhang, D H; Zheng, P Y; Zhokhova, S I; Zhou, D C

    1999-03-01

    Angular distributions of charged particles produced in {sup 16}O and {sup 32}S collisions with nuclear track emulsion were studied at momenta 4.5 and 200 A GeV/c. Comparison with the angular distributions of charged particles produced in proton-nucleus collisions at the same momentum allows to draw the conclusion, that the angular distributions in nucleus-nucleus collisions can be seen as superposition of the angular distributions in nucleon-nucleus collisions taken at the same impact parameter b{sub NA}, that is mean impact parameter between the participating projectile nucleons and the center of the target nucleus.

  1. Lens opacities in children of Belarus affected by the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Arinchin, A.N.; Ospennikova, L.A. [Research Clinical Institute of Radiation Medicine and Endocrinology, Ministry of Health, Republic of Belarus, Aksakovschina, Minsk (Belarus)

    1998-03-01

    Reports about the increase in cataracts among the Ukrainian population living in the region of the Chernobyl Atomic Power Plant have been met with certain skepticism. At the same time, American specialists do not exclude the possibility of radiation genesis of lensopathias revealed among the citizens of Ukraine at the result of complex joint clinic-epidemiological study conducted by American and Ukrainian specialists in 1991. The aim of the investigation was to study the frequency and character of lens opacities in children permanently residing in the contaminated territories of the Republic of Belarus with anomalous high coefficients of {sup 137}Cs radionuclides through the food chain. It is well known that radiation cataract is one of the direct effects of ionizing radiation. Organ of sight is highly radiosensitive. The most radio-vulnerable part of eye is lens in which cataract is developing in response to both external and internal exposure. In children, focal lens opacities are localized in embryonic nucleus, but in elderly people, alongside with embryonic nucleus, they are also localized in adult nucleus and cortical layers. Lens opacity is the result of biochemical changes occurring in it, and it is caused by lens fibers damage. Frequency of occurrence of lensopathias in children from the main group made 82.1% which is by 12.5% more than in the control, mostly due to opacities in both lenses. (J.P.N.)

  2. Lens opacities in children of Belarus affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    Arinchin, A.N.; Ospennikova, L.A.

    1998-01-01

    Reports about the increase in cataracts among the Ukrainian population living in the region of the Chernobyl Atomic Power Plant have been met with certain skepticism. At the same time, American specialists do not exclude the possibility of radiation genesis of lensopathias revealed among the citizens of Ukraine at the result of complex joint clinic-epidemiological study conducted by American and Ukrainian specialists in 1991. The aim of the investigation was to study the frequency and character of lens opacities in children permanently residing in the contaminated territories of the Republic of Belarus with anomalous high coefficients of 137 Cs radionuclides through the food chain. It is well known that radiation cataract is one of the direct effects of ionizing radiation. Organ of sight is highly radiosensitive. The most radio-vulnerable part of eye is lens in which cataract is developing in response to both external and internal exposure. In children, focal lens opacities are localized in embryonic nucleus, but in elderly people, alongside with embryonic nucleus, they are also localized in adult nucleus and cortical layers. Lens opacity is the result of biochemical changes occurring in it, and it is caused by lens fibers damage. Frequency of occurrence of lensopathias in children from the main group made 82.1% which is by 12.5% more than in the control, mostly due to opacities in both lenses. (J.P.N.)

  3. A role for smoothened during murine lens and cornea development.

    Directory of Open Access Journals (Sweden)

    Janet J Y Choi

    Full Text Available Various studies suggest that Hedgehog (Hh signalling plays roles in human and zebrafish ocular development. Recent studies (Kerr et al., Invest Ophthalmol Vis Sci. 2012; 53, 3316-30 showed that conditionally activating Hh signals promotes murine lens epithelial cell proliferation and disrupts fibre differentiation. In this study we examined the expression of the Hh pathway and the requirement for the Smoothened gene in murine lens development. Expression of Hh pathway components in developing lens was examined by RT-PCR, immunofluorescence and in situ hybridisation. The requirement of Smo in lens development was determined by conditional loss-of-function mutations, using LeCre and MLR10 Cre transgenic mice. The phenotype of mutant mice was examined by immunofluorescence for various markers of cell cycle, lens and cornea differentiation. Hh pathway components (Ptch1, Smo, Gli2, Gli3 were detected in lens epithelium from E12.5. Gli2 was particularly localised to mitotic nuclei and, at E13.5, Gli3 exhibited a shift from cytosol to nucleus, suggesting distinct roles for these transcription factors. Conditional deletion of Smo, from ∼E12.5 (MLR10 Cre did not affect ocular development, whereas deletion from ∼E9.5 (LeCre resulted in lens and corneal defects from E14.5. Mutant lenses were smaller and showed normal expression of p57Kip2, c-Maf, E-cadherin and Pax6, reduced expression of FoxE3 and Ptch1 and decreased nuclear Hes1. There was normal G1-S phase but decreased G2-M phase transition at E16.5 and epithelial cell death from E14.5-E16.5. Mutant corneas were thicker due to aberrant migration of Nrp2+ cells from the extraocular mesenchyme, resulting in delayed corneal endothelial but normal epithelial differentiation. These results indicate the Hh pathway is required during a discrete period (E9.5-E12.5 in lens development to regulate lens epithelial cell proliferation, survival and FoxE3 expression. Defective corneal development occurs

  4. Crystalline lens thickness determines the perceived chromatic difference in magnification.

    Science.gov (United States)

    Chen, Yun; Schaeffel, Frank

    2014-03-01

    Since the origin of the high interindividual variability of the chromatic difference in retinal image magnification (CDM) in the human eye is not well understood, optical parameters that might determine its magnitude were studied in 21 healthy subjects with ages ranging from 21 to 58 years. Two psychophysical procedures were used to quantify CDM. They produced highly correlated results. First, a red and a blue square, presented on a black screen, had to be matched in size by the subjects with their right eyes. Second, a filled red and blue square, flickering on top of each other at 2 Hz, had to be adjusted in perceived brightness and then in size to minimize the impression of flicker. CDM varied widely among subjects from 0.0% to 3.6%. Biometric ocular parameters were measured with low coherence interferometry and crystalline lens tilt and decentration with a custom-built Purkinjemeter. Correlations were studied between CDM and corneal power, anterior chamber depth, lens thickness, lens tilt and lens decentration, and vitreous chamber depths. Lens thickness was found significantly correlated with CDM and accounted for 64% of its variance. Vertical lens tilt and decentration were also significantly correlated. It was also found that CDM increased by 3.5% per year, and part of this change can be attributed to the age-related increase in lens thickness.

  5. The imaginary part of the nucleus - nucleus optical potential

    International Nuclear Information System (INIS)

    Phatak, S.C.; Sinha, B.

    1978-01-01

    The contribution to the imaginary nucleus - nucleus optical potential has been estimated by evaluating the energy - conserving seocond-order term in the perturbation series. The incoming nuclear field is supposed to excite nucleons in a nucleus in this calculation and the nuclear excitations are approximated by particle-hole excitations in a Fermi gas. The resulting imaginary potential compares favourably with phenomenological potentials. (author)

  6. The Correlation between Daily Lens Wear Duration and Dry Eye Syndrome.

    Science.gov (United States)

    Lubis, Rodiah Rahmawaty; Gultom, Monica Tumiar Hanna

    2018-05-20

    To analyze the correlation between the daily lens wear duration and dry eye syndrome. This study was an analytic cross sectional study using consecutive sampling conducted among the students in Economy and Bussiness Faculty and Faculty of Humanities in University of Sumatera Utara aged between 17 to 23 that wore contact lens continously for at least a year and 5 days a week. The symptoms were assessed using Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and interview about their contact lens comfort; eye drops usage, contact lens washing habit, daily circumstances, places to buy contact lens and personal experince in wearing contact lens. The questionnaire was completed by 53 students. All of them were female and wore softlens wearers. The mean duration of daily wear was 8.19 ± 2.20 hours. The most common symptom experienced was dry eye and the least symptom experienced was removing lens. The most frequent symptom experienced was closing eyes and the least frequent symptom experienced was removing lenses. This study used Exact Test as analysis statistic method. The result was p > 0.05 which means there is no correlation between daily lens wear duration and dry eye syndrome. This study showed that dry eye syndrome was not correlated with daily lens wear duration, but affected by many factors such as contact lens, lens care solution, eye drops usage and environment.

  7. Global features of nucleus-nucleus collisions in ultrarelativistic domain

    International Nuclear Information System (INIS)

    Savina, M.V.; Shmatov, S.V.; Slavin, N.V.; Zarubin, P.I.

    1998-01-01

    HIJING generator simulation of nucleus-nucleus collisions at ultrarelativistic energies is presented. It is shown that the global characteristics of nucleus-nucleus collisions, such as distribution of a charged multiplicity, total and electromagnetic transverse energy over pseudorapidity are rather sensitive to some predictions of models of high-exited nuclear medium formation, namely parton energy losses in dense nuclear matter. These losses result in appearance of a broad maximum in global variable distributions over pseudorapidity. The most profound of this effect occurs at central heavy ion collisions at LHC energy

  8. Higgs-boson production in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider

  9. Higgs-Boson Production in Nucleus-Nucleus Collisions

    Science.gov (United States)

    Norbury, John W.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  10. Visualization of transverse diffusion paths across fiber cells of the ocular lens by small animal MRI

    International Nuclear Information System (INIS)

    Vaghefi, Ehsan; Hunter, Peter J; Jacobs, Marc D; Pontre, Beau; Donaldson, Paul J

    2009-01-01

    The sense of vision requires that light penetrate through the ocular lens. Experiments, performed and published by many research groups, have suggested that the lens, which has no blood vessels, relies on internally directed ion and water fluxes for its circulation, survival and transparency. We investigated the internal diffusive pathways of the lens in order to better understand the constraints that may be operating on directional lens fluxes. Small animal magnetic resonance imaging, including T2-weighted and diffusion tensor imaging, was used to measure tissue properties and diffusivity throughout cultured bovine lenses. A range of concentric regions of signal intensity was distinguished inside the lens, by both T2-weighted signal and mean diffusivity. Diffusivity mapping of the lens revealed novel anisotropic polar and equatorial zones of pronounced diffusivity directed transverse to the fiber cells. In contrast, an inner zone including the lens nucleus showed isotropic and weak diffusivity. Our results lend support to models of internally directed lens micro-circulation, by placing non-structural diffusive constraints on global patterns of fluid circulation

  11. A Correlation of Thin Lens Approximation to Thick Lens Design by Using Coddington Factors in Lens Design and Manufacturing

    OpenAIRE

    FARSAKOĞLU, Ö. Faruk

    2014-01-01

    The effect of Coddington factors on aberration functions has been analysed using thin lens approximation. Minimizing spherical aberrations of singlet lenses using Coddington factors in lens design depending on lens manufacturing is discussed. Notation of lens test plate pairs used in lens manufacturing is also presented in terms of Coddington shape factors.

  12. Surgical treatment of hereditary lens subluxations.

    Science.gov (United States)

    Ozdek, Sengul; Sari, Ayca; Bilgihan, Kamil; Akata, Fikret; Hasanreisoglu, Berati

    2002-01-01

    To evaluate the effectiveness and results of pars plana vitreolensectomy approach with transscleral fixation of intraocular lens in hereditary lens subluxations. Fifteen eyes of 9 consecutive patients with a mean age of 12.8+/-6.2 years (6-26 years) with hereditary lens subluxation were operated on and the results were evaluated in a prospective study. Surgery was considered if best spectacle corrected visual acuity (BSCVA) was less than 20/70. All eyes underwent a 2-port pars plana vitreolensectomy and transscleral fixation of an intraocular lens (IOL). The mean follow-up period was 12.6+/-7.5 months (6-22 months). There was no major intraoperative complication. Preoperatively, 8 eyes (53.3%) had a BSCVA of counting fingers (CF) and 7 eyes (46.6%) had a BSCVA of 20/200 to 20/70. Postoperatively, 14 eyes (93.3%) had a BSCVA of 20/50 or better. None of the patients had IOL decentration or intraocular pressure (IOP) increase during the follow-up period. There was a macular hole formation in 1 eye postoperatively. The early results of pars plana vitreolensectomy with IOL implantation using scleral fixation technique had shown that it not only promises a rapid visual rehabilitation but it is also a relatively safe method. More serious complications, however, may occur in the long term.

  13. [Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position].

    Science.gov (United States)

    Arraes, Caroline; Endriss, Daniela; Lobato, Francisco; Arraes, João; Ventura, Marcelo

    2010-01-01

    To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL) and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients with congenital lens subluxation who underwent the same surgical technique, by the same surgeon. The study was performed in the ''Hospital de Olhos de Pernambuco'' and ''Fundação Altino Ventura''. The surgical technique consisted of phacoaspiration with implant of endocapsular ring and intraocular lens with one loop haptic amputated. The age varied from 7 to 22 years. Data on visual acuity (VA) before and after surgery, surgery follow-up period, and complications were analyzed. All patients underwent ultrasound biomicroscopy. The mean follow-up period was 2.8 years. There was a VA improvement in 17 (100%) eyes: in 12 eyes (70.6%) the visual acuity was better than 20/40; 4 (23.5%) ranged from 20/40 to 20/100, and 1 (5.9%) had visual acuity worse than 20/100, however better than the preoperative visual acuity. The posterior capsular opacification occurred in 10 eyes (58.9%). Ultrasound biomicroscopy showed that all IOL were partially decentralized, however without surpassing the pupil border limit. Endocapsular ring position was correct and there was a good capsular support in all cases. The evaluated surgical treatment provided good intraocular lens and endocapsular ring position, with VA improvement Thus, this technique is a viable, effective and safe option for the visual rehabilitation of patients with congenital lens subluxation.

  14. Novel Scanning Lens Instrument for Evaluating Fresnel Lens Performance: Equipment Development and Initial Results (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, R.; Miller, D. C.; Kurtz, S. R.; Anton, I.; Sala, G.

    2013-07-01

    A system dedicated to the optical transmittance characterization of Fresnel lenses has been developed at NREL, in collaboration with the UPM. The system quantifies the optical efficiency of the lens by generating a performance map. The shape of the focused spot may also be analyzed to understand change in the lens performance. The primary instrument components (lasers and CCD detector) have been characterized to confirm their capability for performing optical transmittance measurements. Measurements performed on SoG and PMMA lenses subject to a variety of indoor conditions (e.g., UV and damp heat) identified differences in the optical efficiency of the evaluated lenses, demonstrating the ability of the Scanning Lens Instrument (SLI) to distinguish between the aged lenses.

  15. Reactive Oxygen Species and the Aging Eye: Specific Role of Metabolically Active Mitochondria in Maintaining Lens Function and in the Initiation of the Oxidation-Induced Maturity Onset Cataract--A Novel Platform of Mitochondria-Targeted Antioxidants With Broad Therapeutic Potential for Redox Regulation and Detoxification of Oxidants in Eye Diseases.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2016-01-01

    The aging eye appears to be at considerable risk from oxidative stress. A great deal of research indicates that dysfunctional mitochondria are the primary site of reactive oxygen species (ROS). More than 95% of O2 produced during normal metabolism is generated by the electron transport chain in the inner mitochondrial membrane. Mitochondria are also the major target of ROS. Cataract formation, the opacification of the eye lens, is one of the leading causes of human blindness worldwide, accounting for 47.8% of all causes of blindness. Cataracts result from the deposition of aggregated proteins in the eye lens and lens fiber cell plasma membrane damage, which causes clouding of the lens, light scattering, and obstruction of vision. ROS-induced damage in the lens cell may consist of oxidation of proteins, DNA damage, and/or lipid peroxidation, all of which have been implicated in cataractogenesis. This article is an attempt to integrate how mitochondrial ROS are altered in the aging eye along with those protective and repair therapeutic systems believed to regulate ROS levels in ocular tissues and how damage to these systems contributes to age-onset eye disease and cataract formation. Mitochondria-targeted antioxidants might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo. As a result of the combination of weak metal chelating, OH and lipid peroxyl radicals scavenging, reducing activities to liberated fatty acid, and phospholipid hydroperoxides, carnosine and carcinine appear to be physiological antioxidants able to efficiently protect the lipid phase of biologic membranes and aqueous environments and act as the antiapoptotic natural drug compounds The authors developed and patented the new ophthalmic compositions, including N-acetylcarnosine, acting as a prodrug of naturally targeted to mitochondria L-carnosine endowed with pluripotent antioxidant activities combined with mitochondria

  16. Delayed diagnosis of homocystinuria presenting as bilateral congenital lens subluxation

    OpenAIRE

    Jelić-Vuković Marija; Matić Suzana; Barać Josip; Novinščak Tomislav; Belovari Mirna; Barić Hrvoje

    2017-01-01

    Introduction. Homocystinuria is an autosomal recessively inherited defect leading to hyperhomocysteinemia and associated with ocular manifestations, mainly myopia and ectopia lentis. Case outline. A 26-year-old male with secondary glaucoma due to bilateral lens subluxation was admitted to the Department of vitreoretinal surgery. Horizontal nystagmus, bilateral lens subluxation, and bilateral amblyopia were first discovered at the age of three years. Preoperative laboratory workup revealed ele...

  17. Scaling phenomenon in relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Wong, C.Y.; Blankenbecler, R.

    1980-01-01

    New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures

  18. Momentum loss in proton-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Khan, F.; Townsend, L.W.

    1993-12-01

    An optical model description, based on multiple scattering theory, of longitudinal momentum loss in proton-nucleus and nucleus-nucleus collisions is presented. The crucial role of the imaginary component of the nucleon-nucleon transition matrix in accounting for longitudinal momentum transfer is demonstrated. Results obtained with this model are compared with Intranuclear Cascade (INC) calculations, as well as with predictions from Vlasov-Uehling-Uhlenbeck (VUU) and quantum molecular dynamics (QMD) simulations. Comparisons are also made with experimental data where available. These indicate that the present model is adequate to account for longitudinal momentum transfer in both proton-nucleus and nucleus-nucleus collisions over a wide range of energies

  19. Calculation of crystalline lens power in chickens with a customized version of Bennett's equation.

    Science.gov (United States)

    Iribarren, Rafael; Rozema, Jos J; Schaeffel, Frank; Morgan, Ian G

    2014-03-01

    This paper customizes Bennett's equation for calculating lens power in chicken eyes from refraction, keratometry and biometry. Previously published data on refraction, corneal power, anterior chamber depth, lens thickness, lens radii of curvature, axial length and eye power in chickens aged 10-90 days were used to estimate Gullstrand's lens power and Bennett's lens power for chicken eyes, and to calculate the lens equivalent refractive index. Bennett's A and B constants for the front and back surface powers of the lens were calculated for data measured from day 10 to 90 at 10 day intervals, and mean customized constants were calculated. The mean customized constants for Bennett's equation for chicks were A=0.574±0.023 and B=0.379±0.021. As found previously, lens power decreases with age in chicks, while corneal power decreases and axial length increases. The lens equivalent refractive index decreases with age from 10 to 90 days after hatching. Bennett's equation can be used to calculate lens power in chicken eyes for studies on animal myopia, using standard biometry. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Model for nucleus-nucleus, hadron-nucleus and hadron-proton multiplicity distributions

    International Nuclear Information System (INIS)

    Singh, C.P.; Shyam, M.; Tuli, S.K.

    1986-07-01

    A model relating hadron-proton, hadron-nucleus and nucleus-nucleus multiplicity distributions is proposed and some interesting consequences are derived. The values of the parameters are the same for all the processes and are given by the QCD hypothesis of ''universal'' hadronic multiplicities which are found to be asymptotically independent of target and beam in hadronic and current induced reactions in particle physics. (author)

  1. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  2. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. [Seoul National University Hospital (Korea, Republic of)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  3. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    International Nuclear Information System (INIS)

    Rehani, M.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  4. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    International Nuclear Information System (INIS)

    Park, J.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  5. A stereological study of the mediodorsal thalamic nucleus in Down syndrome

    DEFF Research Database (Denmark)

    Karlsen, A S; Korbo, S; Uylings, H B M

    2014-01-01

    The total number of neurons and glial cells in the mediodorsal thalamic (MDT) nucleus of four aged females with Down syndrome (DS; mean age 69years) was estimated and compared to six age- and sex-matched controls. The MDT nucleus was delineated on coronal sections, and cell numbers (large and small...

  6. Characteristics of the thick, compound refractive lens

    International Nuclear Information System (INIS)

    Pantell, Richard H.; Feinstein, Joseph; Beguiristain, H. Raul; Piestrup, Melvin A.; Gary, Charles K.; Cremer, Jay T.

    2003-01-01

    A compound refractive lens (CRL), consisting of a series of N closely spaced lens elements each of which contributes a small fraction of the total focusing, can be used to focus x rays or neutrons. The thickness of a CRL can be comparable to its focal length, whereupon a thick-lens analysis must be performed. In contrast with the conventional optical lens, where the ray inside the lens follows a straight line, the ray inside the CRL is continually changing direction because of the multiple refracting surfaces. Thus the matrix representation for the thick CRL is quite different from that for the thick optical lens. Principal planes can be defined such that the thick-lens matrix can be converted to that of a thin lens. For a thick lens the focal length is greater than for a thin lens with the same lens curvature, but this lengthening effect is less for the CRL than for the conventional optical lens

  7. The intercalatus nucleus of Staderini.

    Science.gov (United States)

    Cascella, Marco

    2016-01-01

    Rutilio Staderini was one of the leading Italian anatomists of the twentieth century, together with some scientists, such as Giulio Chiarugi, Giovanni Vitali, and others. He was also a member of a new generation of anatomists. They had continued the tradition of the most famous Italian scientists, which started from the Renaissance up until the nineteenth century. Although he carried out important studies of neuroanatomy and comparative anatomy, as well as embryology, his name is rarely remembered by most medical historians. His name is linked to the nucleus he discovered: the Staderini nucleus or intercalated nucleus, a collection of nerve cells in the medulla oblongata located lateral to the hypoglossal nucleus. This article focuses on the biography of the neuroanatomist as well as the nucleus that carries his name and his other research, especially on comparative anatomy and embryology.

  8. Treatment of contact lens related dry eye with antibacterial honey.

    Science.gov (United States)

    Wong, Daniel; Albietz, Julie M; Tran, Huan; Du Toit, Cimonette; Li, Anita Hui; Yun, Tina; Han, Jee; Schmid, Katrina L

    2017-12-01

    Contact lens induced dry eye affects approximately 50% of contact lens wearers. The aim was to assess the effects of Manuka (Leptospermum sp.) honey eye drops (Optimel, Melcare, Australia) on dry eye in contact lens wearers. The safety of the honey eye drops in contact lens wear and contact lens wearers' compliance were also evaluated. Prospective, randomised, cross over study, examiner masked, pilot treatment trial. Twenty-four participants aged 20 to 55 years with contact lens related dry eye were recruited and randomised to two treatment groups; 20 completed the study. One group used Optimel eye drops twice a day for two weeks followed by conventional lubricant (Systane Ultra, Alcon) therapy for two weeks; the other group completed the treatments in the reverse order. Before and after each treatment dry eye symptomology, ocular surface inflammation, and tear quantity and quality were assessed. Participants completed a daily log detailing their usage of treatments and any issues. Dry eye symptoms improved significantly after Optimel treatment. Patients with more severe symptoms at baseline showed a greater improvement in symptoms. No significant differences were observed in the objective signs of dry eye; presumably because of the short treatment duration. Seventy-five% of contact lens wearers reported good adherence to Optimel treatment and 95% reported no issues using this product. Optimel Eye Drops reduce the symptoms of dry eye in contact lens wearers and are safe to use. A longer treatment period to assess the effect on clinical signs of dry eye is required. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  9. Formation of light particles in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Zagrebaev, V.; Penionzhkevich, Yu.

    1993-01-01

    The principal experimental results on the yield of the light charged particles in nucleus-nucleus collisions at the low and intermediate energies are reviewed. Inclusive spectra of light particles and their coincidences with the characteristic KX-rays, γ-rays, neutrons, projectile-like fragments, other light particles, fission fragments, and evaporation residues are analyzed. The main theoretical models used for the description of the light particle formation are briefly outlined together with their merits and shortcomings. The unsolved problems of fast light particle formation, in particular, and of nucleus-nucleus interaction dynamics, on the whole, are discussed with the outlooks of new experiments able to clear up some of these problems. (author) 144 refs., 40 figs., 2 tabs

  10. Nucleus-nucleus interactions in the transition energy regime

    International Nuclear Information System (INIS)

    Volant, C.

    1985-02-01

    There are at least two ways for studying large interactions in nucleus-nucleus collisions. One way is to use the method of angular correlations between fission fragments. The aim of the experiments presented here was to make a survey on the role of the various experimental parameters. In that respect three targets have been studied and different projectiles and bombarding energies have been used. Results are presented and discussed

  11. Diabatic interaction potential for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Noerenberg, W.; Lukasiak, A.

    1984-01-01

    Within a refined method for the construction of diabatic states allowing for the treatment of the full spin-orbit coupling, characteristic features of the diabatic potential for nucleus-nucleus collisions are investigated. Approximately 90% of the strong repulsion results from diabatic particle-hole excitations, while only 10% is due to compression. The diabatic interaction potential describes a physical situation intermediate between adiabatic and sudden approximations. (orig.)

  12. Crystalline lens radioprotectors

    International Nuclear Information System (INIS)

    Belkacemi, Y.; Pasquier, D.; Castelain, B.; Lartigau, E.; Warnet, J.M.

    2003-01-01

    During more than a half of century, numerous compounds have been tested in different models against radiation-induced cataract. In this report, we will review the radioprotectors that have been already tested for non-human crystalline lens protection. We will focus on the most important published studies in this topic and the mechanisms of cyto-protection reported in. vitro and in. vivo from animals. The most frequent mechanisms incriminated in the cyto-protective effect are: free radical scavenging, limitation of lipid peroxidation, modulation of cycle progression increase of intracellular reduced glutathione pool, reduction of DNA strand breaks and limitation of apoptotic cell death. Arnifostine (or Ethyol) and anethole dithiolethione (or Sulfarlem), already used clinically as chemo- and radio-protectants, could be further test?r for ocular radioprotection particularly for radiation-induced cataract. (author)

  13. Wedged multilayer Laue lens

    International Nuclear Information System (INIS)

    Conley, Ray; Liu Chian; Qian Jun; Kewish, Cameron M.; Macrander, Albert T.; Yan Hanfei; Maser, Joerg; Kang, Hyon Chol; Stephenson, G. Brian

    2008-01-01

    A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures

  14. Goat′s eye integrated with a human cataractous lens: A training model for phacoemulsification

    Directory of Open Access Journals (Sweden)

    Sabyasachi Sengupta

    2015-01-01

    Full Text Available A relatively simple and inexpensive technique to train surgeons in phacoemulsification using a goat′s eye integrated with a human cataractous nucleus is described. The goat′s eye is placed on a bed of cotton within the lumen of a cylindrical container. This is then mounted on a rectangular thermocol so that the limbus is presented at the surgical field. After making a clear corneal entry with a keratome, the trainer makes a 5-5.5 mm continuous curvilinear capsulorhexis in the anterior lens capsule, creates a crater of adequate depth in the cortex and inserts the human nucleus within this crater in the goat′s capsular bag. The surgical wound is sutured, and the goat′s eye is ready for training. Creating the capsulorhexis with precision and making the crater of adequate depth to snugly accommodate the human nucleus are the most important steps to prevent excessive wobbling of the nucleus while training.

  15. Goat's eye integrated with a human cataractous lens: A training model for phacoemulsification.

    Science.gov (United States)

    Sengupta, Sabyasachi; Dhanapal, Praveen; Nath, Manas; Haripriya, Aravind; Venkatesh, Rengaraj

    2015-03-01

    A relatively simple and inexpensive technique to train surgeons in phacoemulsification using a goat's eye integrated with a human cataractous nucleus is described. The goat's eye is placed on a bed of cotton within the lumen of a cylindrical container. This is then mounted on a rectangular thermocol so that the limbus is presented at the surgical field. After making a clear corneal entry with a keratome, the trainer makes a 5-5.5 mm continuous curvilinear capsulorhexis in the anterior lens capsule, creates a crater of adequate depth in the cortex and inserts the human nucleus within this crater in the goat's capsular bag. The surgical wound is sutured, and the goat's eye is ready for training. Creating the capsulorhexis with precision and making the crater of adequate depth to snugly accommodate the human nucleus are the most important steps to prevent excessive wobbling of the nucleus while training.

  16. Refractive power and biometric properties of the nonhuman primate isolated crystalline lens.

    Science.gov (United States)

    Borja, David; Manns, Fabrice; Ho, Arthur; Ziebarth, Noel M; Acosta, Ana Carolina; Arrieta-Quintera, Esdras; Augusteyn, Robert C; Parel, Jean-Marie

    2010-04-01

    Purpose. To characterize the age dependence of shape, refractive power, and refractive index of isolated lenses from nonhuman primates. Methods. Measurements were performed on ex vivo lenses from cynomolgus monkeys (cyno: n = 120; age, 2.7-14.3 years), rhesus monkeys (n = 61; age, 0.7-13.3 years), and hamadryas baboons (baboon: n = 16; age, 1.7-27.3 years). Lens thickness, diameter, and surface curvatures were measured with an optical comparator. Lens refractive power was measured with a custom optical system based on the Scheiner principle. The refractive contributions of the gradient, the surfaces, and the equivalent refractive index were calculated with optical ray-tracing software. The age dependence of the optical and biometric parameters was assessed. Results. Over the measured age range isolated lens thickness decreased (baboon: -0.04, cyno: -0.05, and rhesus: -0.06 mm/y) and equatorial diameter increased (logarithmically for the baboon and rhesus, and linearly for cyno: 0.07 mm/y). The isolated lens surfaces flattened and the corresponding refractive power from the surfaces decreased with age (-0.33, -0.48, and -0.68 D/y). The isolated lens equivalent refractive index decreased (only significant for the baboon, -0.001 D/y), and as a result the total isolated lens refractive power decreased with age (baboon: -1.26, cyno: -0.97, and rhesus: -1.76 D/y). Conclusions. The age-dependent trends in the optical and biometric properties, growth, and aging, of nonhuman primate lenses are similar to those of the pre-presbyopic human lens. As the lens ages, the decrease in refractive contributions from the gradient refractive index causes a rapid age-dependent decrease in maximally accommodated lens refractive power.

  17. K+ nucleus total cross sections

    International Nuclear Information System (INIS)

    Sawafta, R.

    1990-01-01

    The scattering of K + mesons from nuclei has attracted considerable interest in the last few years. The K + holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K + is capable of probing the entire volume of the nucleus. Single scattering of the K + with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K + is used to compare the nucleon in the nucleus with a free nucleon

  18. Eye lens radiation exposure in Greek interventional cardiology personnel

    International Nuclear Information System (INIS)

    Thrapsanioti, Zoi; Askounis, Panagiotis; Carinou, Eleftheria; Datseris, Ioannis; Diamanti, Ramza Anastasia; Papathanasiou, Miltiadis

    2017-01-01

    The lens of the eye is one of the radiosensitive tissues of the human body; if exposed to ionizing radiation can develop radiation-induced cataract at early ages. This study was held in Greece and included 44 Interventional Cardiologists (ICs) and an unexposed to radiation control group of 22 persons. Of the note, 26 ICs and the unexposed individuals underwent special eye examinations. The detected lens opacities were classified according to LOCS III protocol. Additionally, the lens doses of the ICs were measured using eye lens dosemeters. The mean dose to the lenses of the ICs per month was 0.83 ± 0.59 mSv for the left and 0.35 ± 0.38 mSv for the right eye, while the annual doses ranged between 0.7 and 11 mSv. Regarding the lens opacities, the two groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities, whereas four ICs were detected with early stage subcapsular sclerosis. Though no statistically difference was observed in the cohort, the measured doses indicate that the eye doses received from the ICs can be significant. To minimize the radiation-induced risk at the eye lenses, the use of protective equipment and appropriate training on this issue is highly recommended. (authors)

  19. Scleral suspension pars-plana lensectomy for ectopia lentis followed by suture fixation of intraocular lens

    Directory of Open Access Journals (Sweden)

    Mitra Sandip

    2001-01-01

    Full Text Available Purpose: To describe a simple technique of scleral suspension-pars plana lensectomy (SS-PPL in acquired and congenital ectopia lentis and scleral fixation of intraocular lens (IOL. Materials and Methods: Twenty eyes of 16 patients (12 unilateral and 4 bilateral cases of "essential familial lens subluxation" aged 10-40 years (mean 25 years underwent SS-PPL with implantation of scleral fixated IOL. Indications for surgery were best-corrected visual acuity <6/18, bisection of pupil by the lens, and lens-induced glaucoma. Prerequisites for SS-PPL were, visibility of part of the lens in the pupillary area and soft lens. Results: Postoperative visual acuity ranged from 6/6 - 6/36. Lens tilt in 3 cases(15% and small decentration in 2 cases(10% were seen; however these did not seriously compromise the visual result. Scant vitreous bleeding on the first postoperative day was seen in 3 cases (15%. Conclusion: The advantages of the scleral suspension of subluxated lens prior to lensectomy include stabilization; it allows proper viewing of the lens, avoids injury to the iris and cliary body during lensectomy and reduces the possibility of dislocation of the lens.

  20. Compliance among soft contact lens wearers.

    Science.gov (United States)

    Kuzman, Tomislav; Kutija, Marija Barisić; Masnec, Sanja; Jandroković, Sonja; Mrazovac, Danijela; Jurisić, Darija; Skegro, Ivan; Kalauz, Miro; Kordić, Rajko

    2014-12-01

    Contact lens compliance is proven to be crucial for preventing lens wear-related complications because of the interdependence of the steps in lens care regime and their influence on lens system microbial contamination. Awareness of the patients' lens handling compliance as well as correct recognition of non-compliant behaviours is the basis for creating more targeted strategies for patient education. The aim of this study was to investigate compliance among soft contact lens (SCL) wearers in different aspects of lens care handling and wearing habits. In our research 50 asymptomatic lens wearers filled out a questionnaire containing demographic data, lens type, hygiene and wearing habits, lenses and lens care system replacement schedule and self-evaluation of contact lens handling hygiene. We established criteria of compliance according to available manufacturer's recommendations, prior literature and our clinical experience. Only 2 (4%) of patients were fully compliant SCL wearers. The most common non-compliant behaviours were insufficient lens solution soaking time (62%), followed by failure to daily exchange lens case solution and showering while wearing lenses. 44% of patients reported storing lenses in saline solution. Mean lens storage case replacement was 3.6 months, with up to 78% patients replacing lens case at least once in 3 months. Average grade in self evaluating level of compliance was very good (4 +/- 0.78) (from 1-poor level of hygiene to 5-great level of hygiene). Lens wearers who reported excessive daily lens wear and more than 10 years of lens wearing experience were also found to be less compliant with other lens system care procedures. (t = -2.99, df=47, p rate, self grading was relatively high. Therefore, these results indicate the need for patient education and encouragement of better lens wearing habits and all of the lens maintenance steps at each patient visit.

  1. Nanoceria have no genotoxic effect on human lens epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pierscionek, Barbara K; Yasseen, Akeel A [School of Biomedical Sciences, University of Ulster, Coleraine, BT52 1SA (United Kingdom); Li, Yuebin; Schachar, Ronald A; Chen, Wei [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Colhoun, Liza M, E-mail: b.pierscionek@ulster.ac.uk, E-mail: weichen@uta.edu [Centre for Vision and Vascular Sciences, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Grosvenor Road, Belfast, BT12 6BA (United Kingdom)

    2010-01-22

    There are no treatments for reversing or halting cataract, a disease of the structural proteins in the eye lens, that has associations with other age-related degenerative conditions such as Alzheimer's disease. The incidence of cataract and associated conditions is increasing as the average age of the population rises. Protein folding diseases are difficult to assess in vivo as proteins and their age-related changes are assessed after extraction. Nanotechnology can be used to investigate protein changes in the intact lens as well as for a potential means of drug delivery. Nanoparticles, such as cerium oxide (CeO{sub 2}) which have antioxidant properties, may even be used as a means of treating cataract directly. Prior to use in treatments, nanoparticle genotoxicity must be tested to assess the extent of any DNA or chromosomal damage. Sister chromatid exchanges were measured and DNA damage investigated using the alkaline COMET assay on cultured human lens epithelial cells, exposed to 5 and 10 {mu}g ml{sup -1} of CeO{sub 2} nanoparticles (nanoceria). Nanoceria at these dosages did not cause any DNA damage or significant increases in the number of sister chromatid exchanges. The absence of genotoxic effects on lens cells suggests that nanoceria, in the doses and exposures tested in this study, are not deleterious to the eye lens and have the potential for use in studying structural alterations, in developing non-surgical cataract treatments and in investigating other protein folding diseases.

  2. Contact Lens-Related Eye Infections

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Contact Lens-Related Eye Infections Sections Contact Lens-Related Eye ... Six Steps to Avoid Contact Lens Infections Contact Lens-Related Eye Infections Leer en Español: Infecciones relacionadas ...

  3. 21 CFR 886.1375 - Bagolini lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bagolini lens. 886.1375 Section 886.1375 Food and... OPHTHALMIC DEVICES Diagnostic Devices § 886.1375 Bagolini lens. (a) Identification. A Bagolini lens is a device that consists of a plane lens containing almost imperceptible striations that do not obscure...

  4. Straylight Measurements in Contact Lens Wear

    NARCIS (Netherlands)

    van der Meulen, Ivanka J. E.; Engelbrecht, Leonore A.; van Vliet, Johannes M. J.; Lapid-Gortzak, Ruth; Nieuwendaal, Carla P.; Mourits, Maarten P.; Schlingemann, Reinier O.; van den Berg, Thomas J. T. P.

    2010-01-01

    Purpose: (1) To quantify the effect of contact lens wear on straylight in rigid and soft contact lens wearers and (2) to relate findings to morphological changes and subjective complaints. Methods: Straylight was measured using the Oculus C-Quant during contact lens wear and after contact lens

  5. Immunohistochemical studies of lens crystallins in the dysgenetic lens (dyl) mutant mice

    NARCIS (Netherlands)

    Brahma, S.K.; Sanyal, S.

    1984-01-01

    The lens in the dyl mutant mice shows a persistent lens-ectodermal connection as well as degeneration and extrusion of lens materials after the initial differentiation of the fibres. Immunohistochemical investigation of the ontogeny of the lens crystallins in this developing mutant lens has been

  6. Contact Lens Related Corneal Ulcer

    OpenAIRE

    Loh, KY; Agarwal, P

    2010-01-01

    A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are: overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. Th...

  7. Single lens laser beam shaper

    Science.gov (United States)

    Liu, Chuyu [Newport News, VA; Zhang, Shukui [Yorktown, VA

    2011-10-04

    A single lens bullet-shaped laser beam shaper capable of redistributing an arbitrary beam profile into any desired output profile comprising a unitary lens comprising: a convex front input surface defining a focal point and a flat output portion at the focal point; and b) a cylindrical core portion having a flat input surface coincident with the flat output portion of the first input portion at the focal point and a convex rear output surface remote from the convex front input surface.

  8. No turnover in lens lipids for the entire human lifespan.

    Science.gov (United States)

    Hughes, Jessica R; Levchenko, Vladimir A; Blanksby, Stephen J; Mitchell, Todd W; Williams, Alan; Truscott, Roger J W

    2015-03-11

    Lipids are critical to cellular function and it is generally accepted that lipid turnover is rapid and dysregulation in turnover results in disease (Dawidowicz 1987; Phillips et al., 2009; Liu et al., 2013). In this study, we present an intriguing counter-example by demonstrating that in the center of the human ocular lens, there is no lipid turnover in fiber cells during the entire human lifespan. This discovery, combined with prior demonstration of pronounced changes in the lens lipid composition over a lifetime (Hughes et al., 2012), suggests that some lipid classes break down in the body over several decades, whereas others are stable. Such substantial changes in lens cell membranes may play a role in the genesis of age-related eye disorders. Whether long-lived lipids are present in other tissues is not yet known, but this may prove to be important in understanding the development of age-related diseases.

  9. A course in lens design

    CERN Document Server

    Velzel, Chris

    2014-01-01

    A Course in Lens Design is an instruction in the design of image-forming optical systems. It teaches how a satisfactory design can be obtained in a straightforward way. Theory is limited to a minimum, and used to support the practical design work. The book introduces geometrical optics, optical instruments and aberrations. It gives a description of the process of lens design and of the strategies used in this process. Half of its content is devoted to the design of sixteen types of lenses, described in detail from beginning to end. This book is different from most other books on lens design because it stresses the importance of the initial phases of the design process: (paraxial) lay-out and (thin-lens) pre-design. The argument for this change of accent is that in these phases much information can be obtained about the properties of the lens to be designed. This information can be used in later phases of the design. This makes A Course in Lens Design a useful self-study book, and a suitable basis for an intro...

  10. Influence of Gravity on Ocular Lens Position.

    Science.gov (United States)

    Lister, Lucas J; Suheimat, Marwan; Verkicharla, Pavan K; Mallen, Edward A H; Atchison, David A

    2016-04-01

    We determined whether human ocular lens position is influenced by gravity. Anterior chamber depth (ACD) and lens thickness (LT) were determined with a Haag-Streit Lenstar LS900 for right eyes of participants in two age groups, with a young group of 13 participants aged 18 to 21 years (mean, 21 years; SD, 1 year) and an older group of 10 participants aged 50 to 63 years (mean, 58 years; SD, 4 years). There were two sessions for each participant separated by at least 48 hours, with one session for the usual upright head position and one session for a downwards head position. In a session, testing was done for minimum accommodation followed by testing at maximum accommodation. A drop of 2% pilocarpine nitrate was instilled, and testing was repeated after 30 minutes under minimum and maximum accommodation conditions. Gravity, manipulated through head posture, affected ACD for young adult and older adult groups but mean effects were only small, ranging from 0.04 to 0.12 mm, and for the older group required the instillation of an accommodation-stimulating drug. Gravity had a weakly significant effect on LT for the young group without accommodation or a drug, but the effect was small at 0.04 ± 0.06 mm (mean ± SD, P = 0.04). There is a small but real effect of gravity on crystalline lens position, manifested as reduction in ACD at high levels of accommodative effort with the head in a downwards position. This provides evidence of the ability of zonules to slacken during strong accommodation.

  11. Dimuon enhancement in nucleus-nucleus ultrarelativistic interactions

    International Nuclear Information System (INIS)

    Bordalo, Paula; Abreu, M.C.; Alessandro, B.; Alexa, C.; Arnaldi, R.; Astruc, J.; Atayan, M.; Baglin, C.; Baldit, A.; Bedjidian, M.; Bellaiche, F.; Beole, S.; Bohrani, A.; Boldea, V.; Bussiere, A.; Capelli, L.; Caponi, V.; Casagrande, L.; Castor, J.; Chambon, T.; Chaurand, B.; Chevrot, I.; Cheynis, B.; Chiavassa, E.; Cicalo, C.; Comets, M.P.; Constans, N.; Constantinescu, S.; Contardo, D.; Cruz, J.; De Falco, A.; De Marco, N.; Dellacasa, G.; Devaux, A.; Dita, S.; Drapier, O.; Ducroux, L.; Espagnon, B.; Fargeix, J.; Ferreira, R.; Filippov, S.N.; Fleuret, F.; Force, P.; Gallio, M.; Gavrilov, Y.K.; Gerschel, C.; Giubellino, P.; Golubeva, M.B.; Gonin, M.; Gorodetzky, P.; Grigorian, A.A.; Grossiord, J.Y.; Guber, F.F.; Guichard, A.; Gulkanyan, H.; Hakobyan, R.; Haroutunian, R.; Idzik, M.; Jouan, D.; Karavitcheva, T.L.; Kluberg, L.; Kossakowski, R.; Kurepin, A.B.; Landau, G.; Le Bornec, Y.; Lourenco, C.; Luquin, L.; Macciotta, P.; Mac Cormick, M.; Mandry, R.; Marzari-Chiesa, A.; Masera, M.; Masoni, A.; Mehrabyan, S.; Monteno, M.; Mourgues, S.; Musso, A.; Ohlsson-Malek, F.; Petiau, P.; Piccotti, A.; Pizzi, J.R.; Prado da Silva, W.L.; Puddu, G.; Quintans, C.; Racca, C.; Ramello, L.; Ramos, S.; Rato-Mendes, P.; Riccati, L.; Romana, A.; Ropotar, I.; Saturnini, P.; Scomparin, E.; Serci, S.; Shahoyan, R.; Silva, S.; Sitta, M.; Soave, C.; Sonderegger, P.; Tarrago, X.; Topilskaya, N.S.; Usai, G.L.; Varela, J.; Vercellin, E.; Villatte, L.

    1999-01-01

    The study of muon pairs in the mass region 1.5 μμ 2 in 450 GeV/c p-A, 200 GeV/nucleon S-U and 158 GeV/nucleon Pb-Pb collisions is presented. In p-A interactions, the dimuon signal mass spectra are well described by a superposition of Drell-Yan and charmed meson semi-leptonic decay contributions, in agreement with previous experiments when considering a linear A dependence. In nucleus-nucleus reactions, taking only into account these two physical ingredients, a dimuon enhancement both with increasing A·B and centrality is observed

  12. The incorporation of 2-[14C]glycine into porcine lens protein

    International Nuclear Information System (INIS)

    Lee, Y.B.; Kauffman, R.G.; DeVenecia, G.

    1977-01-01

    A series of experiments was conducted to estimate the apparent turnover rate of lens soluble protein, the incorporation rate of 2-[ 14 C]glycine into various soluble protein components and the effect of nutritional stress on the disappearance of radioactivity with time. Evidence is presented that there are two fractions of soluble lens protein with different turnover rates: one is a fast turnover fraction with a half-life of 20.8 hr and the other is a metabolically inert fraction with an infinitely long half-life. It is postulated that the fast turnover fraction is present in the newly-formed younger fibers in the periphery, whereas the inert fraction is in the old lens fibers of the cortex and nucleus. Sephadex G-200 column chromatography was used to separate the soluble lens protein into four components: A, B, C and D in the order of elution. The changes in specific activities of the four components with the time course after injection were followed. Prolonged starvation did not affect the disappearance of carbon incorporated into lens protein with the time course after injection, suggesting normal synthesis and degradation of lens protein without regard to dietary stress. (author)

  13. Effects of photobleaching on selected advanced glycation end products in the human lens

    DEFF Research Database (Denmark)

    Holm, Thomas; Raghavan, Cibin T; Nahomi, Rooban

    2015-01-01

    at examining the optical and biochemical effects of the proposed treatment.MethodsHuman donor lenses were photobleaced using a 445 nm cw laser. Lens optical quality was assessed before and after photobleaching by light transmission and scattering. The concentration of the advanced glycation end products (AGEs...... of the photobleaching treatment on lens optical parameters but we could not associate the optical findings to a change in the concentration of the AGEs we measured. This finding suggests that other AGEs were responsible for the observed photobleaching of the human lens after laser treatment. The biochemical nature...

  14. Assessment of phacoaspiration techniques in clear lens extraction for correction of high myopia

    Directory of Open Access Journals (Sweden)

    Mostafa A El-Helw

    2010-03-01

    Full Text Available Mostafa A El-Helw, Ahmed M EmarahDepartment of Ophthalmology, Cairo University, EgyptPurpose: To evaluate various phacoaspiration techniques in clear lens extraction for the incidence of intraoperative difficulties and complications.Patients and methods: This was a prospective study in which bilateral clear lens extraction was performed on 40 eyes of 20 patients, to correct high myopia. The patients were divided into 2 groups: group A underwent supracapsular phacoaspiration; group B were the contralateral eyes of the same patient. These patients were operated on with endocapsular phacoaspiration with the divide and conquer (D and C technique. Preoperative ocular examination data were recorded and tested for significance. Intraoperative difficulties and complications such as nucleus cracking, capsule rupture and vitreous loss, and repeated chamber collapse were recorded. Postoperative examination data were recorded.Results: Mean age was 35.65 ± 5.85 years. Mean follow-up time was 17.1 ± 8.56 months. In group A mean myopia was -17.3 ± 5.07 diopters; in group B myopia was -17.9 ± 4.20 diopters. Mean preoperative uncorrected visual acuity (UCVA was 0.04 ± 0.0167, while the mean postoperative UCVA was 0.435 ± 0.1442. There was a significant difference in pre and postoperative BCVA within both groups, but not between the two groups. In both groups endothelial cell count (ECC showed a significant difference between pre- and postoperative data; however, there was no statistically significant difference between both groups in postoperative ECC. The effective phacoaspiration time for group A was 4.6 ± 1.6 seconds, and for group B 9.90 ± 2.27 seconds (P < 0.005. No cases of capsule rupture occurred in group A, but 3 cases occurred in group B (15 % (not significant, P = 0.231. Nucleus cracking did not occur in group A, but in group B 13 cases occurred (65%. Chamber collapse occurred in 4 cases (20% in group A and 5 cases (25% in group B (not

  15. The momentum distribution inside nucleus

    International Nuclear Information System (INIS)

    Fujita, T.

    1985-01-01

    Discussions are made on several reactions which can determine the momentum distribution inside nucleus. The first reaction discussed is the high energy heavy ion collision. This reaction involves many nucleons which interact strongly. Therefore, one must be careful for any possible final state interactions. The expression for the single particle momentum distribution is given. And it can be said that the expression is consistent with the description of the energetic neutrons from muon capture by heavy nucleus. The best way to determine the momentum distribution would be the lepton-nucleus scattering since it does not involve the strong interaction in the initial channel. Another reaction discussed is the backward proton production, which is governed by quite complicated reaction processes. Therefore, the determination of the momentum distribution is only indirect. Noverthless, it is found that this reaction presents a very interesting and important information on the momentum distribution. (Aoki, K.)

  16. Nucleus management with irrigating vectis

    Directory of Open Access Journals (Sweden)

    Srinivasan Aravind

    2009-01-01

    Full Text Available The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS, incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost.

  17. Efficacy on chopping with lens loop-pad in the small incision extracapsular cataract surgery with intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Xiao-Ning Peng

    2014-04-01

    Full Text Available AIM: To study the clinical effects of chopping with lens loop-pad in the small incision extracapsular cataract surgery with intraocular lens implantation.METHODS:A total of 75 cases(80 eyes, in which loop-pad and chop knife were performed to chop nucleus before implanting intraocular lens. Visual acuity, postoperative astigmatism degree, intraoperative and postoperative complications were observed. The post-operative follow-up periods ranged from 3 to 12mo.RESULTS: The visual acuity was 0.3-0.5 in 37 eyes and 0.6 or better in 21 eyes at 1d, while was respectively in 43 eyes and in 26 eyes at 1mo. Compared with preoperative astigmatism(0.85±0.29D, there were significant difference at postoperative 1wk(1.75±0.55D(PP>0.05. Intraoperative posterior capsule rupture occurred in 4 eyes, which implantation was successful in 1 eye and 3 eyes was managed viaciliary sulcus. Two eyes had dermatoglyphic pattern edema in corneal endothelium which recovered after about 3d. Two eyes had local patchy opacities which recovered in 2wk. Two eyes had transient high intraocular pressure.CONCLUSION: The surgery is efficient, low cost, easy process and less complications, it is worth to be popularized.

  18. Formin' actin in the nucleus.

    Science.gov (United States)

    Baarlink, Christian; Grosse, Robert

    2014-01-01

    Many if not most proteins can, under certain conditions, change cellular compartments, such as, for example, shuttling from the cytoplasm to the nucleus. Thus, many proteins may exert functions in various and very different subcellular locations, depending on the signaling context. A large amount of actin regulatory proteins has been detected in the mammalian cell nucleus, although their potential roles are much debated and are just beginning to emerge. Recently, members of the formin family of actin nucleators were also reported to dynamically localize to the nuclear environment. Here we discuss our findings that specific diaphanous-related formins can promote nuclear actin assembly in a signal-dependent manner.

  19. Anti p-nucleus interaction

    International Nuclear Information System (INIS)

    Peng, J.C.

    1986-05-01

    Status and future prospects of antiproton-nucleus scattering experiments are presented. These scattering experiments were conducted at antiproton beam momentums of 300 and 600 MeV/c on target nuclei of 6 Li, 12 C, 16 O, 18 O, 40 Ca, 48 Ca, and 208 Pb. Antiproton-proton reactions investigated antiproton-nucleus bound or resonant states in antiproton reactions with d, 6 Li, 12 C, 63 Cu, and 209 Bi. Inelastic scattering experiments investigated the spin-isospin dependence of the NN interactions. 19 refs., 1 fig., 1 tab

  20. Age

    Science.gov (United States)

    ... adults? How can you reduce anesthesia risks in older patients? Age Age may bring wisdom but it also brings ... Ask your physician to conduct a pre-surgery cognitive test — an assessment of your mental function. The physician can use the results as a ...

  1. Lens thickness assessment: anterior segment optical coherence tomography versus A-scan ultrasonography

    Directory of Open Access Journals (Sweden)

    Nikoo Hamzeh

    2015-12-01

    Full Text Available AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT in comparison with A-scan ultrasonography (A-scan US. METHODS: There were 218 adult subjects (218 eyes aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III. Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA. The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74. Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001, and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001 CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

  2. A theoretical lens for revealing the complexity of chronic care

    NARCIS (Netherlands)

    Borgermans, L.; de Maeseneer, J.; Wollersheim, H.; Vrijhoef, H.J.M.; Devroey, D.

    2013-01-01

    The increasing prevalence of co-occurring multiple chronic conditions in an aging population has influenced the debate on complexity in chronic care and nowadays provides an impetus to the reform of numerous health systems. This article presents a theoretical lens for understanding the complexity of

  3. Functionalized active-nucleus complex sensor

    Science.gov (United States)

    Pines, Alexander; Wemmer, David E.; Spence, Megan; Rubin, Seth

    2003-11-25

    A functionalized active-nucleus complex sensor that selectively associates with one or more target species, and a method for assaying and screening for one or a plurality of target species utilizing one or a plurality of functionalized active-nucleus complexes with at least two of the functionalized active-nucleus complexes having an attraction affinity to different corresponding target species. The functionalized active-nucleus complex has an active-nucleus and a targeting carrier. The method involves functionalizing an active-nucleus, for each functionalized active-nucleus complex, by incorporating the active-nucleus into a macromolucular or molecular complex that is capable of binding one of the target species and then bringing the macromolecular or molecular complexes into contact with the target species and detecting the occurrence of or change in a nuclear magnetic resonance signal from each of the active-nuclei in each of the functionalized active-nucleus complexes.

  4. Aging

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Kodama, Kazunori; Yamada, Michiko

    1991-01-01

    The hypothesis that exposure to ionizing radiation accelerates the aging process has been actively investigated at ABCC-RERF since 1958, when longitudinal cohort studies of the Adult Health Study (AHS) and the Life Span Study (LSS) were initiated. In their 1975 overall review of aging studies related to the atomic bomb (A-bomb) survivors, Finch and Beebe concluded that while most studies had shown no correlation between aging and radiation exposure, they had not involved the large numbers of subjects required to provide strong evidence for or against the hypothesis. Extending LSS mortality data up to 1978 did not alter the earlier conclusion that any observed life-shortening was associated primarily with cancer induction rather than with any nonspecific cause. The results of aging studies conducted during the intervening 15 years using data from the same populations are reviewed in the present paper. Using clinical, epidemiological, and laboratory techniques, a broad spectrum of aging parameters have been studied, such as postmortem morphological changes, tests of functional capacity, physical tests and measurements, laboratory tests, tissue changes, and morbidity. With respect to the aging process, the overall results have not been consistent and are generally thought to show no relation to radiation exposure. Although some preliminary results suggest a possible radiation-induced increase in atherosclerotic diseases and acceleration of aging in the T-cell-related immune system, further study is necessary to confirm these findings. In the future, applying the latest gerontological study techniques to data collected from subjects exposed 45 years ago to A-bomb radiation at relatively young ages will present a new body of data relevant to the study of late radiation effects. (author) 103 refs

  5. The nucleus as a laboratory

    International Nuclear Information System (INIS)

    Blin-Stoyle, R.J.

    1979-01-01

    The nucleus is a complicated many-body structure whose properties when carefully studied can frequently give important information about the underlying elementary particle interactions. This article reviews progress in research of this kind over the last twenty-five years. (author)

  6. The pion-nucleus interaction

    International Nuclear Information System (INIS)

    Afnan, I.R.

    1977-04-01

    The latest developments in the construction of pion-nucleus optical potential are presented and a comparison with the latest data on π+ 12 C is made. The suggested mechanisms for the (p,π) reaction are discussed with a comparison of the theoretical results with experiment. (Author)

  7. Aging

    International Nuclear Information System (INIS)

    Finch, S.C.; Beebe, G.W.

    1975-01-01

    The hypothesis that ionizing radiation accelerates natural aging has been under investigation at the Atomic Bomb Casualty Commission since 1959. Postmortem observations of morphologic and chemical changes, tests of functional capacity, physical tests and measurements, clinical laboratory tests, tissue changes, morbidity, and mortality have all been examined by ABCC investigators interested in this hypothesis. These studies have been beset with conceptual difficulties centered on the definition and measurement of aging. An empirical approach early led to the calculation of an index of physiologic age as a linear combination of age-related tests of various organ systems. Most studies have been negative but have not involved the large numbers that might be required to provide strong evidence for or against the hypothesis. Mortality, however, has been examined on the basis of a large sample and over the period 1950-1972 had provided no support for the hypothesis of radiation-accelerated aging. Ionizing radiation dose, of course shorten human life, but its life-shortening effect appears to be the result of specific radiation-induced disease, especially neoplasms. The hypothesis is now much less attractive than it was 10-20 years ago but still has some value in stimulating research on aging. The experience of the A-bomb survivors provides an unusual opportunity for a definitive test of the hypothesis. (auth.)

  8. Delayed diagnosis of homocystinuria presenting as bilateral congenital lens subluxation

    Directory of Open Access Journals (Sweden)

    Jelić-Vuković Marija

    2017-01-01

    Full Text Available Introduction. Homocystinuria is an autosomal recessively inherited defect leading to hyperhomocysteinemia and associated with ocular manifestations, mainly myopia and ectopia lentis. Case outline. A 26-year-old male with secondary glaucoma due to bilateral lens subluxation was admitted to the Department of vitreoretinal surgery. Horizontal nystagmus, bilateral lens subluxation, and bilateral amblyopia were first discovered at the age of three years. Preoperative laboratory workup revealed elevated levels of homocysteine. Bilateral pars plana lensectomy and vitrectomy followed by a sulcus fixation of the intraocular lens (ALCON MA60 Acrysof IOL were performed. The patient was prescribed folic acid, methionine, and pyridoxine, and was urged to maintain a methionine-low diet. After a bilateral lensectomy and sulcus fixation of the intraocular lens and a methionine restriction therapy combined with vitamin B6, B9, and B12 supplementation, his condition improved greatly. Conclusion. In this report of a rare case we emphasize the importance of examining differential diagnoses of lens subluxation, since early intervention can prevent serious complications.

  9. Tinting of intraocular lens implants

    Energy Technology Data Exchange (ETDEWEB)

    Zigman, S.

    1982-06-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users.

  10. Tinting of intraocular lens implants

    International Nuclear Information System (INIS)

    Zigman, S.

    1982-01-01

    Intraocular lens (IOL) implants of polymethyl methacrylate (PMMA) lack an important yellow pigment useful as a filter in the visual process and in the protection of the retina from short-wavelength radiant energy. The ability to produce a yellow pigment in the PMMA used in IOL implants by exposure to near-ultraviolet (UV) light was tested. It was found that the highly cross-linked material in Copeland lens blanks was tinted slightly because of this exposure. The absorptive properties of lens blanks treated with near-UV light in this way approached that of the absorptive properties of human lenses. This finding shows that it is possible to alter IOL implants simply so as to induce a pale-yellow pigment in them to improve the visual process and to protect the retinas of IOL users

  11. Automated Fresnel lens tester system

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, G.S.

    1981-07-01

    An automated data collection system controlled by a desktop computer has been developed for testing Fresnel concentrators (lenses) intended for solar energy applications. The system maps the two-dimensional irradiance pattern (image) formed in a plane parallel to the lens, whereas the lens and detector assembly track the sun. A point detector silicon diode (0.5-mm-dia active area) measures the irradiance at each point of an operator-defined rectilinear grid of data positions. Comparison with a second detector measuring solar insolation levels results in solar concentration ratios over the image plane. Summation of image plane energies allows calculation of lens efficiencies for various solar cell sizes. Various graphical plots of concentration ratio data help to visualize energy distribution patterns.

  12. Lens system for SIMS analysis

    International Nuclear Information System (INIS)

    Martinez, G.; Sancho, M.; Garcia-Galan, J.C.

    1987-01-01

    A powerful version of the charge-density method is applied to the study of a combined objective and emission lens, suitable for highly localized analysis of a flat sample surface. This lens can extract secondary ions of equal or opposite polarity to that of the primary particles. A computer simulation of the ion trajectories for both modes is made. The behaviour for different values of the geometric parameters and polarizations is analyzed and useful data for design such as primary beam demagnification and secondary image position are given. (author) 4 refs

  13. Combined 23-gauge transconjunctival vitrectomy and scleral fixation of intraocular lens without conjunctival dissection in managing lens complications.

    Science.gov (United States)

    Yeung, Ling; Wang, Nan-Kai; Wu, Wei-Chi; Chen, Kuan-Jen

    2018-04-23

    To evaluate the safety and efficacy of combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of intraocular lens (IOL) without conjunctival dissection. A retrospective study in Chang Gung Memorial Hospital, Keelung and Taoyuan, Taiwan. Patients receiving combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of IOL without conjunctival dissection were enrolled. The ocular findings, causes of lens complication, surgical procedures, type of IOL used, and complications were documented. We included 40 eyes from 39 patients (27 male, 12 female) with a mean age of 59.5 [standard deviation (±) 14.8] years old. The mean follow-up duration was 6.8 ± 5.4 months. The cause of lens complications was ocular trauma in 24 (60%) eyes, cataract surgery complications in 11 (28%) eyes, and spontaneous subluxation of crystalline lens in 5 (13%) eyes. The overall best corrected visual acuity (BCVA) (logMAR) improved from 1.359 ± 0.735 to 0.514 ± 0.582 (p IOL decentration was found in 3 (8%) eyes and 1 (3%) eye respectively. Combined 23-gauge transconjunctival vitrectomy and scleral fixation of IOL without conjunctival dissection is effective and safe in managing a wide variety of lens complications, with good postoperative comfort and visual recovery. Retrospective study, not applicable.

  14. Lens artifacts in human fetal eyes - the challenge of interpreting the histomorphology of human fetal lenses.

    Science.gov (United States)

    Herwig, Martina C; Müller, Annette M; Klarmann-Schulz, Ute; Holz, Frank G; Loeffler, Karin U

    2014-01-01

    Evaluation of the lens, including cataractous changes, is often of paramount importance in the classification of fetal syndromes or forensic questions. On histology, the crystalline lens is - especially in fetal and infant eyes - an organ susceptible to numerous artifacts. Thus, the aim of our study was to study various factors (including fixatives) that might have an impact on lens histomorphology. Twenty eyes from ten fetuses (formalin fixation: n = 10, glutaraldehyde fixation: n = 10), matched for gestational age and abortion (spontaneous vs. induced), were investigated macroscopically and by light microscopy. Sections were stained with routine hematoxylin & eosin (H&E), and periodic acid schiff (PAS). The age of the fetal eyes ranged from 15 to 36 weeks of gestation. Lens artifacts were analyzed and compared to fetal and adult lenses with definitive cataractous changes. In addition, 34 eyes from 27 fetuses with trisomy 21 were investigated for lens changes. All lenses showed artifacts of varying extent, in particular globules, vacuoles, clefts, anterior/posterior capsular separation, subcapsular proteinaceous material, fragmentation of the lens capsule/epithelium, and a posterior umbilication. Glutaraldehyde-fixed lenses displayed less artifacts compared to those fixed in formalin. Slight differences in the appearance of artifacts were found dependent on the fixative (formaldehyde vs glutaraldehyde) and the kind of abortion (iatrogenous vs spontaneous). The gestational age did not have a significant influence on the type and extent of lens artifacts. The lenses from fetuses with trisomy 21 displayed similar lens artifacts with no specific findings. Alterations in fetal lens morphology are extremely frequent and variable. These artifacts have to be carefully taken into account when interpreting post-mortem findings. Thus, the postmortem diagnosis of a fetal cataract should be made with great caution, and should include, in adherence to our proposed

  15. Clinical evaluation of direct and photosensitized ultraviolet radiation damage to the lens

    International Nuclear Information System (INIS)

    Hockwin, O.; Lerman, S.

    1982-01-01

    We are reporting a new, objective, and quantitative method for monitoring age-related molecular changes in the human ocular lens in vivo, as expressed by increases in at least two (nontryptophan) fluorescence wavelengths. These fluorescence wavelengths appear to be caused by photochemically induced changes in the lens, and they reflect the ultraviolet (UV) filtering capacity of the patients' ocular lenses. These data correlate with previously reported in vitro lens fluorescence changes that are associated with the aging process. This method will also detect alterations in lenticular fluorescence caused by photosensitized as well as direct UV radiation damage

  16. Single nucleon emission in relativistic nucleus-nucleus reactions

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors

  17. Transverse Energy in nucleus-nucleus collisions: A review

    International Nuclear Information System (INIS)

    Tincknell, M.

    1988-01-01

    The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs

  18. Refractive lens exchange with a multifocal diffractive aspheric intraocular lens

    Directory of Open Access Journals (Sweden)

    Teresa Ferrer-Blasco

    2012-06-01

    Full Text Available PURPOSE: To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. METHODS: Sixty eyes of 30 patients underwent bilateral implantation with AcrySof® ReSTOR® SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. RESULTS: After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients had an uncorrected visual acuity of 20/20 or better in the myopic and hyperopic groups, respectively. The safety and efficacy indexes were 1.05 and 0.88 for the myopic and 1.01 and 0.86 for the hyperopic groups at distance vision. Within the myopic group, 20 eyes remained unchanged after the surgery, and 3 gained >2 lines of best corrected visual acuity. For the hyperopic group, 2 eyes lost 2 lines of best corrected visual acuity, 21 did not change, and 3 eyes gained 2 lines. At near vision, the safety and efficacy indexes were 1.23 and 1.17 for the myopic and 1.16 and 1.13 for the hyperopic groups. Best corrected near visual acuity improved after surgery in both groups (from 0.10 logMAR to 0.01 logMAR in the myopic group, and from 0.10 logMAR to 0.04 logMAR in the hyperopic group. CONCLUSIONS: The ReSTOR® SN6AD3 intraocular lens in refractive lens exchange demonstrated good safety, efficacy, and predictability in correcting high ametropia and presbyopia.

  19. Stretchable Binary Fresnel Lens for Focus Tuning

    NARCIS (Netherlands)

    Li, X.; Wei, L.; Poelma, R.H.; Vollebregt, S.; Wei, J.; Urbach, Paul; Sarro, P.M.; Zhang, G.Q.

    2016-01-01

    This paper presents a tuneable binary amplitude Fresnel lens produced by wafer-level microfabrication. The Fresnel lens is fabricated by encapsulating lithographically defined vertically aligned carbon nanotube (CNT) bundles inside a polydimethyl-siloxane (PDMS) layer. The composite lens material

  20. 21 CFR 886.1400 - Maddox lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Maddox lens. 886.1400 Section 886.1400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1400 Maddox lens. (a) Identification. A Maddox lens is a device...

  1. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials such as glass or plastic intended to be implanted to replace the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a...

  2. Kaonic nuclei and kaon-nucleus interactions

    CERN Document Server

    Ikuta, K; Masutani, K

    2002-01-01

    Although kaonic atoms provide valuable information concerning the K sup - -nucleus interaction at low energies, they cannot fully determine the K sup - - nucleus optical potential. We demonstrate that K sup - nuclear bound states, if they exist, can be useful in investigating the K sup - -nucleus interaction, especially in the interior of the nucleus. In order to show this possibility, we calculate the double differential cross sections for (K sup - , P) using the Green function method. (author)

  3. Color oscillations of nucleons in a nucleus

    International Nuclear Information System (INIS)

    Petrov, V.A.; Smirnov, A.Yu.

    1987-01-01

    Possibility of nucleus description as an object consisting of quarks and gluons is considered. A model of two-nucleon interaction in a nucleus is presented and analytical expressions for the nucleus nucleon ground state wave functions and also for nuclear nucleon structure functions are obtained. The carried out analysis shows that the suggested model permits to express the nucleus structure functions at quark level only by means of nucleon and Δ-isobaric degrees of freedom

  4. Compliance and hygiene behaviour among soft contact lens wearers in the Maldives.

    Science.gov (United States)

    Gyawali, Rajendra; Nestha Mohamed, Fathimath; Bist, Jeewanand; Kandel, Himal; Marasini, Sanjay; Khadka, Jyoti

    2014-01-01

    Significant levels of non-compliance and poor hygiene among contact lens wearers have been reported previously from different parts of the world. This survey aimed at identifying the scope of hygiene and non-compliant behaviour of soft contact lens wearers in the Maldives. Established soft lens wearers attending two eye clinics in Male' city, were interviewed in office or via telephone. A set of interviewer-administered questions was used to access the subjective response on compliance and hygiene behaviour (hand and lens case hygiene, water exposure, adherence to lens replacement schedule, dozing and overnight wear, awareness of aftercare visits and reuse of disinfecting solution). Participants were also asked to rate themselves as a contact lens user based on their perceived compliance and hygiene practices. Out of 107 participants, 79 (74.8 per cent) were interviewed in the office and the rest via telephone. The majority of lens wearers were female, office workers and students, with a mean age of 20.64 ± 4.4 years. Mean duration of lens wear was 28.04 ± 8.36 months. Most of them were using spherical lenses (86.9 per cent) on a daily wear basis (96.3 per cent). Major reported forms of non-compliance were poor hand hygiene (60.7 per cent), lack of aftercare awareness (39.3 per cent), water exposure (35.5 per cent) and over-use of lenses (24.3 per cent). While females were more likely to overuse their lenses than males (p hygienic behaviour. A significant number of Maldivian contact lens wearers exhibited poor levels of hygiene and compliance with contact lenses and lens care systems. An effective educational reinforcement strategy needs to be developed to modify lens wearers' non-compliance. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  5. The Ultrawideband Leaky Lens Antenna

    NARCIS (Netherlands)

    Bruni, S.; Neto, A.; Marliani, F.

    2007-01-01

    A novel directive and nondispersive antenna is presented: the ultrawideband (UWB) leaky lens. It is based on the broad band Cherenkov radiation occurring at a slot printed between different infinite homogeneous dielectrics. The first part of the paper presents the antenna concept and the UWB design.

  6. ECTOPIC LENS EXTRACTION IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Vladimir Pfeifer

    2002-12-01

    Full Text Available Background. Ectopia lentis continues to be a therapeutic challenge for ophthalmologists. It can occur as an isolated condition, after ocular trauma, in association with other ocular disorders, as part of a systemic mesodermal disease or a complication of general metabolic disorders. Minimal subluxation of the lens may cause no visual symptoms, but in more advanced cases serious optical disturbances arise. The most important is amblyopia. Surgical treatment options include iris manipulation, lens discission, aspiration, intracapsular or extracapsular extraction, and pars plana lensectomy. The choice of surgical technique remains controversial, in part because of the historically poor visual results and high rate of perioperative complications, including vitreous loss and retinal detachment.Methods. We describe a surgical technique based on the use of the Cionni endocapsular tension ring, dry irrigation aspiration of lens material, centration of the capsular bag and foldable intraocular lens implantation into the bag. With mentioned surgical technique 8 patients were operated; 4 boys and 4 girls, together 11 eyes.Results. The final BCVA after follow up period improved in 9 eyes and it remained the same as before operation in one eye. Statistical comparison of preoperative and postoperative visual acuities showed significant improvement. On the other hand there was no correlation between preoperative and postoperative visual acuity.Conclusions. This surgical procedure is an alternative approach in solving this challenging cases of ectopia lentis with good postoperative visual rehabilitation.

  7. Adjustable internal structure for reconstructing gradient index profile of crystalline lens.

    Science.gov (United States)

    Bahrami, Mehdi; Goncharov, Alexander V; Pierscionek, Barbara K

    2014-03-01

    Employing advanced technologies in studying the crystalline lens of the eye has improved our understanding of the refractive index gradient of the lens. Reconstructing and studying such a complex structure requires models with adaptable internal geometry that can be altered to simulate geometrical and optical changes of the lens with aging. In this Letter, we introduce an optically well-defined, geometrical structure for modeling the gradient refractive index profile of the crystalline lens with the advantage of an adjustable internal structure that is not available with existing models. The refractive index profile assigned to this rotationally symmetric geometry is calculated numerically, yet it is shown that this does not limit the model. The study provides a basis for developing lens models with sophisticated external and internal structures without the need for analytical solutions to calculate refractive index profiles.

  8. Hummingbird Comet Nucleus Analysis Mission

    Science.gov (United States)

    Kojiro, Daniel; Carle, Glenn C.; Lasher, Larry E.

    2000-01-01

    Hummingbird is a highly focused scientific mission, proposed to NASA s Discovery Program, designed to address the highest priority questions in cometary science-that of the chemical composition of the cometary nucleus. After rendezvous with the comet, Hummingbird would first methodically image and map the comet, then collect and analyze dust, ice and gases from the cometary atmosphere to enrich characterization of the comet and support landing site selection. Then, like its namesake, Hummingbird would carefully descend to a pre-selected surface site obtaining a high-resolution image, gather a surface material sample, acquire surface temperature and then immediately return to orbit for detailed chemical and elemental analyses followed by a high resolution post-sampling image of the site. Hummingbird s analytical laboratory contains instrumentation for a comprehensive molecular and elemental analysis of the cometary nucleus as well as an innovative surface sample acquisition device.

  9. Comet Halley: nucleus and jets

    International Nuclear Information System (INIS)

    Sagdeev, R.Z.; Avanesov, G.A.; Barinov, I.V.

    1986-06-01

    The VEGA-1 and VEGA-2 spacecrafts made their closest approach to Comet Halley on 6 and 9 March, respectively. In this paper results of the onboard imaging experiment are discussed. The nucleus of the comet was clearly identifyable as an irregularly shaped object with overall dimensions of (16+-1)x(8+-1)x(8+-1) km. The nucleus rotates around its axis which is nearly perpendicular to the orbital plane, with a period of 53+-2 hours. Its albedo is only 0.04+-002. Most of the jet features observed during the second fly-by were spatially reconstructed. These sources form a quasi-linear structure on the surface. The dust above the surface is shown to be optically thin except certain specific dust jets. Brightness features on the surface are clearly seen. Correlating the data with other measurements it is concluded that the dirty snow-ball model probably has to be revised. (author)

  10. Lasers probe the atomic nucleus

    International Nuclear Information System (INIS)

    Eastham, D.

    1986-01-01

    The article is contained in a booklet on the Revised Nuffield Advanced Physics Course, and concentrates on two techniques to illustrate how lasers probe the atomic nucleus. Both techniques employ resonance fluorescence spectroscopy for obtaining atomic transition energies. The first uses lasers to determine the change in the nuclear charge radius with isotope, the second concerns the use of lasers for ultrasensitive detection of isotopes and elements. The application of lasers in resonance ionization spectroscopy and proton decay is also described. (UK)

  11. Lens stem cells may reside outside the lens capsule: an hypothesis

    Directory of Open Access Journals (Sweden)

    Meyer Rita A

    2007-06-01

    Full Text Available Abstract In this paper, we consider the ocular lens in the context of contemporary developments in biological ideas. We attempt to reconcile lens biology with stem cell concepts and a dearth of lens tumors. Historically, the lens has been viewed as a closed system, in which cells at the periphery of the lens epithelium differentiate into fiber cells. Theoretical considerations led us to question whether the intracapsular lens is indeed self-contained. Since stem cells generate tumors and the lens does not naturally develop tumors, we reasoned that lens stem cells may not be present within the capsule. We hypothesize that lens stem cells reside outside the lens capsule, in the nearby ciliary body. Our ideas challenge the existing lens biology paradigm. We begin our discussion with lens background information, in order to describe our lens stem cell hypothesis in the context of published data. Then we present the ciliary body as a possible source for lens stem cells, and conclude by comparing the ocular lens with the corneal epithelium.

  12. What is a cometary nucleus

    International Nuclear Information System (INIS)

    Lyttleton, R.A.

    1977-01-01

    Descriptions of actual observed comets associate a range of ill-defined meanings with the term nucleus. In recent years use of the word has been even further extended (or contracted) to mean a postulated solid core constituting the permanent element of a comet and necessarily of size far below resolution and measurability. It is maintained by the postulants that this core, acted upon by solar radiation and the solar wind, is the fount and origin of practically the whole great variety of observed cometary physical phenomena. In order that this micro-nucleus shall 'explain' observed properties, it is endowed with a large number of entirely ad-hoc qualities specially devised to produce the very effects it is wished to explain, but the processes so proffered rely almost entirely on purely verbal asseverations that they will work in the way required. No source or mechanism of origin for the imaginary micro-nucleus, of which there would need to be myriads, is in sight, nor can the assumption explain the dynamical properties of long-period comets and their association with the galactic plane and the solar apex. The postulate is in any event ruled out by Occam's principle as having no basis in fact or theory and is not required to explain the observed properties of comets. The large number of additional special assumptions introduced mean that the structure as a whole does not constitute a proper scientific theory. (author)

  13. Efficient generation of lens progenitor cells from cataract patient-specific induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Xiaodi Qiu

    Full Text Available The development of a technique to induce the transformation of somatic cells to a pluripotent state via the ectopic expression of defined transcription factors was a transformational event in the field of regenerative medicine. The development of this technique also impacted ophthalmology, as patient-specific induced pluripotent stemcells (iPSCs may be useful resources for some ophthalmological diseases. The lens is a key refractive element in the eye that focuses images of the visual world onto the retina. To establish a new model for drug screening to treat lens diseases and investigating lens aging and development, we examined whether human lens epithelial cells (HLECs could be induced into iPSCs and if lens-specific differentiation of these cells could be achieved under defined chemical conditions. We first efficiently reprogrammed HLECs from age-related cataract patients to iPSCs with OCT-4, SOX-2, and KLF-4. The resulting HLEC-derived iPS (HLE-iPS colonies were indistinguishable from human ES cells with respect to morphology, gene expression, pluripotent marker expression and their ability to generate all embryonic germ-cell layers. Next, we performed a 3-step induction procedure: HLE-iPS cells were differentiated into large numbers of lens progenitor-like cells with defined factors (Noggin, BMP and FGF2, and we determined that these cells expressed lens-specific markers (PAX6, SOX2, SIX3, CRYAB, CRYAA, BFSP1, and MIP. In addition, HLE-iPS-derived lens cells exhibited reduced expression of epithelial mesenchymal transition (EMT markers compared with human embryonic stem cells (hESCs and fibroblast-derived iPSCs. Our study describes a highly efficient procedure for generating lens progenitor cells from cataract patient HLEC-derived iPSCs. These patient-derived pluripotent cells provide a valuable model for studying the developmental and molecular biological mechanisms that underlie cell determination in lens development and cataract

  14. Modern lens antennas for communications engineering

    CERN Document Server

    Thornton, John

    2012-01-01

    The aim of this book is to present the modern design principles and analysis of lens antennas. It gives graduates and RF/Microwave professionals the design insights in order to make full use of lens antennas.  Why do we want to write a book in lens antennas? Because this topic has not been thoroughly publicized, its importance is underestimated. As antennas play a key role in communication systems, recent development in wireless communications would indeed benefit from the characteristics of lens antennas: low profile, and low cost etc.  The major advantages of lens antennas are na

  15. Angular momentum and incident-energy dependence of nucleus-nucleus interaction

    International Nuclear Information System (INIS)

    Yamaguchi, S.

    1991-01-01

    The purpose of this paper is to understand intuitively the origin of the angular momentum and incident-energy dependence of the nucleus-nucleus interaction on the basis of the totally- antisymmetrized many-body theory. With the aim of understanding the structure of the nucleus-nucleus interaction, we show first that the nucleus-nucleus interaction can be written by the use of the density-distribution function and the phase-space distribution function instead of using the many-body wave function itself. And we show that the structure change of the density-distribution function with the increase of the angular momentum causes the angular momentum dependence of the nucleus-nucleus interaction and that the incident-energy dependence of the nucleus-nucleus interaction originates from the structure change of the phase-space distribution function

  16. Contact lens surface by electron beam

    International Nuclear Information System (INIS)

    Shin, Jung Hyuck; Lee, Suk Ju; Hwang, Kwang Ha; Jeon Jin

    2011-01-01

    Contact lens materials needs good biocompatibility, high refractive index, high optical transparency, high water content etc. Surface treat method by using plasma and radiation can modify the physical and/or chemical properties of the contact lens surface. Radiation technology such as electron beam irradiation can apply to polymerization reaction and enhance the functionality of the polymer.The purpose of this study is to modify of contact lens surface by using Eb irradiation technology. Electron beam was irradiated to the contact lens surface which was synthesized thermal polymerization method and commercial contact lens to modify physical and chemical properties. Ft-IR, XP, UV-vis spectrophotometer, water content, oxygen trans-metastability were used to characterize the surface state, physicochemical, and optical property of the contact lens treated with Eb. The water content and oxygen transmissibility of the contact lens treated with Eb were increased due to increase in the hydrophilic group such as O-C=O and OH group on the contact lens surface which could be produced by possible reaction between carbon and oxygen during the Eb irradiation. All of the lenses showed the high optical transmittance above 90%. In this case of B/Es, TES, Ti contact lens, the optical transmittance decreased about 5% with increasing Eb dose in the wavelength of UV-B region. The contact lens modified by Eb irradiation could improve the physical properties of the contact lens such as water content and oxygen transmissibility

  17. Lens decenter and tilt measurement by interferogram

    Science.gov (United States)

    Hung, Min-Wei; Wu, Wen-Hong; Huang, Kuo-Cheng

    2009-11-01

    For the recent years, the vigorous development of the electro-optic industry, particularly the digital camera and the cellular phone camera, has placed a larger and larger demand for the optical devices. Among the optical lens, the aspherical optical lens plays the key component because the aspherical lens may provide better imaging quality then the spherical lens does. For the manufacturing reason, the aspherical lens is prone to a decenter or tilt issue with respect to the optical axes of its two surfaces. To measure decenter and tile error specifically would help to obviate the deficient lens, but most of the present measuring method can't provide this function. This paper proposed a new method to specifically measure the decenter and tile of lens by observing the interferogram of each surface. And the corresponding measuring instrument, which contains interferometer and motion stages, was introduced as well.

  18. Plasma Lens for Muon and Neutrino Beams

    Science.gov (United States)

    Kahn, Stephen; Korenev, Sergey; Bishai, Mary; Diwan, Milind; Gallardo, Juan; Hershcovitch, Ady; Johnson, Brant

    2008-04-01

    The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-current lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. A plasma lens has additional advantage: larger axial current than horns, minimal neutrino contamination during antineutrino running, and negligible pion absorption or scattering. Results from particle simulations using a plasma lens will be presented.

  19. Classifiers for centrality determination in proton-nucleus and nucleus-nucleus collisions

    Directory of Open Access Journals (Sweden)

    Altsybeev Igor

    2017-01-01

    Full Text Available Centrality, as a geometrical property of the collision, is crucial for the physical interpretation of nucleus-nucleus and proton-nucleus experimental data. However, it cannot be directly accessed in event-by-event data analysis. Common methods for centrality estimation in A-A and p-A collisions usually rely on a single detector (either on the signal in zero-degree calorimeters or on the multiplicity in some semi-central rapidity range. In the present work, we made an attempt to develop an approach for centrality determination that is based on machine-learning techniques and utilizes information from several detector subsystems simultaneously. Different event classifiers are suggested and evaluated for their selectivity power in terms of the number of nucleons-participants and the impact parameter of the collision. Finer centrality resolution may allow to reduce impact from so-called volume fluctuations on physical observables being studied in heavy-ion experiments like ALICE at the LHC and fixed target experiment NA61/SHINE on SPS.

  20. Impact of crystalline lens opacification on effective phacoemulsification time in femtosecond laser-assisted cataract surgery.

    Science.gov (United States)

    Mayer, Wolfgang J; Klaproth, Oliver K; Hengerer, Fritz H; Kohnen, Thomas

    2014-02-01

    To compare effective phacoemulsification time in cataract surgery performed by manual phacoemulsification vs femtosecond laser-assisted lens fragmentation. Retrospective, consecutive, nonrandomized, comparative case series. The setting was the Department of Ophthalmology, Goethe-University, Frankfurt, Germany. The study population included 150 eyes of 86 patients with senile cataract. In the intervention, 88 eyes (group 1) underwent femtosecond laser-assisted surgery (corneal incisions, capsulotomy, lens fragmentation) using the LenSx platform (Alcon) and residual lens work-up with pulsed ultrasound energy (Infiniti Vision System; Alcon). In 62 eyes (group 2), complete cataract removal was performed with phacoemulsification only, using pulsed ultrasound energy with the same device (Infiniti). Nucleus staging (Pentacam nucleus staging; PNS) was evaluated using Pentacam HR (Oculus); endothelial cell density was measured using specular microscopy (NonCon Robo). The main outcome measures were as follows. Mean preoperative PNS staging was assessed using an automatic ordinal scaling (PNS-O, grades 0-5) and a manually defined density grid derived from Scheimpflug imaging (PNS-P [%]). Effective phacoemulsification time and endothelial cell loss were evaluated in both groups. Preoperative PNS-O and PNS-P showed no significant difference between groups (P = 0.267). Overall mean effective phacoemulsification time was significantly lower in group 1 (1.58 ± 1.02 seconds) compared to 4.17 ± 2.06 seconds in group 2 (P = 0.001). Effective phacoemulsification time was significantly lower in group 1 for all PNS-O stages (P < 0.001). With increasing preoperative PNS-P, effective phacoemulsification time increased in both groups; however, this gain was noticeably, but not significantly, lower in group 2. Endothelial cell loss was significantly lower in group 1 (P = 0.02). Femtosecond laser-assisted cataract surgery allows a significant reduction in effective phacoemulsification time

  1. Photoproduction of lepton pairs in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, B. D.; Goncalves, V. P.; De Santana Amaral, J. T. [Universidade Federal de Pelotas, Instituto de Fisica e Matematica (Brazil)

    2013-03-25

    In this contribution we study coherent interactions as a probe of the nonlinear effects in the Quantum Electrodynamics (QED). In particular, we study the multiphoton effects in the production of leptons pairs for proton-nucleus and nucleus-nucleus collisions for heavy nuclei. In the proton-nucleus we assume the ultrarelativistic proton as a source of photons and estimate the photoproduction of lepton pairs on nuclei at RHIC and LHC energies considering the multiphoton effects associated to multiple rescattering of the projectile photon on the proton of the nucleus. In nucleus - nucleus colllisions we consider the two nuclei as a source of photons. As each scattering contributes with a factor {alpha}Z to the cross section, this contribution must be taken into account for heavy nuclei. We consider the Coulomb corrections to calculate themultiple scatterings and estimate the total cross section for muon and tau pair production in proton-nucleus and nucleus-nucleus collisions at RHIC and LHC energies.

  2. Mechanism research of miR-181 regulating human lens epithelial cell apoptosis

    Directory of Open Access Journals (Sweden)

    Yu Qin

    2015-05-01

    Full Text Available AIM: To investigate the expression of miR-181 in the lens tissue of cataract and the regulating mechanism of miR-181 on apoptosis of human lens epithelial cell.METHODS:Real time q-PCR was used to measure the expression of miR-181 in the anterior lens capsules of age-related cataract and human lens epithelial cell apoptosis model. miR-181 mimic and inhibitor were transfected using Lipofectamine 2 000 to regulate the expression of miR-181, and then Real time q-PCR was used to verify transfection efficiency. Flow cytometry was used to detect the change of cell apoptosis rate. RESULTS: Compared with control group, the expression of miR-181 was significantly higher in both the anterior lens capsules of age-related cataract and human lens epithelial cell apoptosis model; the relative expression of miR-181 in lens epithelial cells transfected with miR-181 mimic was increased, whereas decreased in cells transfected with miR-181 inhibitor; the apoptosis rate of cells transfected with miR-181 mimic was increased, while reduced in miR-181 inhibitor group. Each result was statistically significant(PCONCLUSION: High expression of miR-181 is detected in anterior lens capsule of age-related cataract. miR-181 might play a certain role in the pathogenesis of cataract via promoting human lens epithelial cell apoptosis. miR-181 probably becomes a new approach for the nonoperative treatment of cataract, but the concrete mechanism still needs to be further studied.

  3. Diffusion of nanoparticles into the capsule and cortex of a crystalline lens

    International Nuclear Information System (INIS)

    Schachar, Ronald A; Chen Wei; Woo, Boon K; Pierscionek, Barbara K; Zhang, Xing; Ma, Lun

    2008-01-01

    The purpose of this study is to determine the ability of fluorescent nanoparticles to diffuse into a crystalline lens. Intact porcine lenses from five-month-old pigs, intact human lenses obtained from three donors aged 41, 42 and 45 years, and sections of human lens cortex obtained from four donors aged 11, 19, 32, and 34 years were incubated for 72 h at 7 deg. C in aqueous solutions of green (566 nm) and red (652 nm) fluorescent water soluble cadmium tellurium (CdTe) nanoparticles. As demonstrated by fluorescent and confocal microscopy, the CdTe nanoparticles diffused into the porcine and human lens capsule and into human cortical lens fibres; however, the nanoparticles did not pass through the intact lens capsule. Nanoparticles can be used as a method for studying intracellular structure and biochemical pathways within the lens capsule and cortical lens fibres to further understand cataractogenesis and may serve as a carrier for chemotherapeutic agents for the potential treatment of primary and secondary cataracts

  4. Decreased number of oxytocin neurons in the paraventricular nucleus of the human hypothalamus in AIDS

    NARCIS (Netherlands)

    Purba, J. S.; Hofman, M. A.; Portegies, P.; Troost, D.; Swaab, D. F.

    1993-01-01

    The number of immunocytochemically identified vasopressin (AVP) and oxytocin (OXT) neurons was determined morphometrically in the paraventricular nucleus of the hypothalamus of 20 acquired immunodeficiency syndrome (AIDS) patients and 10 controls. The AIDS group consisted of 14 homosexual males (age

  5. Telomere Attrition in Human Lens Epithelial Cells Associated with Oxidative Stress Provide a New Therapeutic Target for the Treatment, Dissolving and Prevention of Cataract with N-Acetylcarnosine Lubricant Eye Drops. Kinetic, Pharmacological and Activity-Dependent Separation of Therapeutic Targeting: Transcorneal Penetration and Delivery of L-Carnosine in the Aqueous Humor and Hormone-Like Hypothalamic Antiaging Effects of the Instilled Ophthalmic Drug Through a Safe Eye Medication Technique.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2016-01-01

    the lens response to oxidative damages, aging and health, cataract versus neuroendocrine regulation and disease. The cumulative results demonstrate that carnosine, released ophthalmically from the patented 1% Nacetylcarnosine prodrug lubricant eye drops, at physiological concentration might remarkably reduce the rate of telomere shortening in the lens cells subjected to oxidative stress in the lack of efficient antioxidant lens protection. Carnosine promotes the protection of normal cells from acquiring phenotypic characteristics of cellular senescence. The data of visual functions (visual acuity, glare sensitivity) in older adult subjects and older subjects with cataract treated with 1% N-acetylcarnosine lubricant eye drops showed significant improvement as compared, by contrast with the control group which showed generally no improvement in visual functions, with no difference from baseline in visual acuity and glare sensitivity readings. N-acetylcarnosine derived from the lubricant eye drops may be transported into the hypothalamic tuberomammillary nucleus (TMN) histamine neurons and gradually hydrolyzed. The resulting L-histidine may subsequently be converted into histamine, which could be responsible for the effects of carnosine on neurotransmission and hormone-like antiaging and anti-cataract physiological function. The research utilizing the N-acetylcarnosine lubricant eye drops powerful therapeutic platform provides the findings related to the intraocular uptake exposure sources as well as a timing dosage and duration systemic absorption of said preparation from the conjunctional sac reaching the hypothalamus with activities transfer into the hypothalamic-neuroendocrine pathways affecting across the hypothalamus metabolic pathway the telomere biology and cataract disease occurrence, reversal and prevention and the average expected lifespan of an individual. Such findings can be translated into clinical practice and may provide a basis for personalized cataract

  6. Strangeness production in nucleus-nucleus collisions: An experimental review

    International Nuclear Information System (INIS)

    Odyniec, G.

    1990-12-01

    In experiments with oxygen (60 and 200 GeV/N) and sulphur (200 GeV/N) ions at CERNSPS, large energy densities of the order of 2--3 GeV/fm 3 have been observed, which according to QCD calculations, satisfy necessary conditions for the formation of a quark gluon plasma (QGP) phase. Under such conditions, colour would no longer be confined to hadronic dimensions, and quarks and gluons will propagate freely throughout an extended volume. Somehow lower energy densities, of the order of 0.7--1 GeV/fm 3 , were observed in AGS experiments with 15 GeV/N silicon beams and heavy targets. These energy densities might be adequate for investigations of the pre-equilibrium stage, during which the momentum space distribution has been degradated from its initial value but is not yet thermal. First experimental results, available now, show promise of seeing signs of a new phase of matter. In this review the current status of the selective experimental results on strange-particle production, which are relevant to equilibration and QGP formation in nucleus-nucleus collisions, is presented

  7. Applying the elastic model for various nucleus-nucleus fusion

    International Nuclear Information System (INIS)

    HASSAN, G.S.; RAGAB, H.S.; SEDDEEK, M.K.

    2000-01-01

    The Elastic Model of two free parameters m,d given by Scalia has been used for wider energy regions to fit the available experimental data for potential barriers and cross sections. In order to generalize Scalia's formula in both sub- and above-barrier regions, we calculated m, d for pairs rather than those given by Scalia and compared the calculated cross sections with the experimental data. This makes a generalization of the Elastic Model in describing fusion process. On the other hand, Scalia's range of interacting systems was 24 ≤ A ≤194 where A is the compound nucleus mass number. Our extension of that model includes an example of the pairs of A larger than his final limit aiming to make it as a general formula for any type of reactants: light, intermediate or heavy systems. A significant point is the comparison of Elastic Model calculations with the well known methods studying complete fusion and compound nucleus formation, namely with the resultants of using Proximity potential with either Sharp or Smooth cut-off approximations

  8. Cochlear nucleus neuron analysis in individuals with presbycusis.

    Science.gov (United States)

    Hinojosa, Raul; Nelson, Erik G

    2011-12-01

    The aim of this study was to analyze the cochlear nucleus neuron population in individuals with normal hearing and presbycusis. Retrospective study of archival human temporal bone and brain stem tissues. Using strict inclusion criteria, the temporal bones and cochlear nuclei from six normal hearing individuals and four individuals with presbycusis were selected for analysis. The spiral ganglion cell population, the cochlear nucleus neuron population, and the cell body size of the neurons were quantified in these cases. A relationship was not observed between age and the spiral ganglion cell population in the normal hearing group. Presbycusis subjects exhibited a reduced spiral ganglion cell population. The mean cochlear nucleus neuron population was observed to be significantly higher in the presbycusis group (mean ± standard deviation: 114,170 ± 10,570) compared to the normal hearing group (91,470 ± 9,510) (P = .019). This difference was predominantly the result of greater multipolar and granule cell neuron populations. Only the fusiform neuron type exhibited a significantly different mean cell body cross-sectional area between the normal hearing group (242 ± 27) and the presbycusis group (300 ± 37) (P = .033). This investigation is the first time, to our knowledge, that the populations of the eight neuron types in the cochlear nucleus have been quantified in both normal hearing individuals and individuals with presbycusis. The data support the concept that presbycusis is not an effect of aging alone but instead may be a condition that predisposes one to hearing loss with advancing age and is characterized by a congenitally elevated cochlear nucleus neuron population. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  9. Lens Coupled Quantum Cascade Laser

    Science.gov (United States)

    Hu, Qing (Inventor); Lee, Alan Wei Min (Inventor)

    2013-01-01

    Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.

  10. Looking beyond the perfect lens

    International Nuclear Information System (INIS)

    Wee, W H; Pendry, J B

    2010-01-01

    The holy grail of imaging is the ability to see through anything. From the conservation of energy, we can easily see that to see through a lossy material would require lenses with gain. The aim of this paper therefore is to propose a simple scheme by which we can construct a general perfect lens, with gain-one that can restore both the phases and amplitudes of near and far fields.

  11. Anterior Lens Capsule and Iris Thicknesses in Pseudoexfoliation Syndrome.

    Science.gov (United States)

    Batur, Muhammed; Seven, Erbil; Tekin, Serek; Yasar, Tekin

    2017-11-01

    The aim of this study was to evaluate anatomic properties of the lens capsule and iris by anterior segment optical coherence tomography (AS-OCT) in patients with pseudoexfoliation (PEX). This prospective study included 62 eyes of 62 patients with PEX syndrome and 43 eyes of 43 age- and gender-matched controls. All subjects underwent full ophthalmologic examinations including AS-OCT. Pupillary diameter, midperipheral stromal iris thickness, central and temporal lens capsule thicknesses, and peripheral pseudoexfoliation material thickness on the anterior lens capsule surface were measured and recorded. Mean age was 66.8 ± 9.3 years in the PEX group and 65.5 ± 8.9 years in the control group (p = 0.44). The PEX group consisted of 62 patients: 38 men (61.3%) and 24 women (38.7%); the control group included 43 subjects: 25 men (58.1%) and 18 women (41.9%). Pupillary diameter after pharmacologic mydriasis was 21% smaller in the PEX group than controls. Mean midperipheral iris thickness was 36 ± 7.2 μm (7.8%) thinner in the PEX group than that of control group (p = 0.047). The central anterior capsule was a mean of 3.40 ± 0.51 μm (18%) thicker in the PEX group compared to the control group (p = 0.0001). The temporal anterior lens capsule was a mean of 0.17 ± 0.15 μm thicker in the PEX group compared to the control group (p = 0.81). With high-resolution OCT imaging, it has become possible to evaluate the anterior lens capsule without histologic examination and demonstrate that it is thicker than normal in PEX patients.

  12. Quarkonia Photoproduction at Nucleus Colliders

    International Nuclear Information System (INIS)

    D'Enterria, David

    2008-01-01

    Exclusive photoproduction of heavy quarkonia in high-energy ultraperipheral ion-ion interactions (γ A →V A, where V = J/ψ, Y and the nucleus A remains intact) offers a useful means to constrain the small-x nuclear gluon density. We discuss preliminary results on J/ψ photoproduction in Au-Au collisions at RHIC [D. d'Enterria [PHENIX Collaboration], Proceeds. Quark Matter'05, (arXiv:nucl-ex/0601001)], as well as full simulation-reconstruction studies of photo-produced Y in Pb-Pb interactions at the LHC [D. d'Enterria (ed.) et al. [CMS Collaboration], J. Phys. G. 34 2307 (2007)

  13. CONTACT LENS RELATED CORNEAL ULCER

    Directory of Open Access Journals (Sweden)

    AGARWAL P

    2010-01-01

    Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

  14. Glycation precedes lens crystallin aggregation

    International Nuclear Information System (INIS)

    Swamy, M.S.; Perry, R.E.; Abraham, E.C.

    1987-01-01

    Non-enzymatic glycosylation (glycation) seems to have the potential to alter the structure of crystallins and make them susceptible to thiol oxidation leading to disulfide-linked high molecular weight (HMW) aggregate formation. They used streptozotocin diabetic rats during precataract and cataract stages and long-term cell-free glycation of bovine lens crystallins to study the relationship between glycation and lens crystallin aggregation. HMW aggregates and other protein components of the water-soluble (WS) and urea-soluble (US) fractions were separated by molecular sieve high performance liquid chromatography. Glycation was estimated by both [ 3 H]NaBH 4 reduction and phenylboronate agarose affinity chromatography. Levels of total glycated protein (GP) in the US fractions were about 2-fold higher than in the WS fractions and there was a linear increase in GP in both WS and US fractions. This increase was parallelled by a corresponding increase in HMW aggregates. Total GP extracted by the affinity method from the US fraction showed a predominance of HMW aggregates and vice versa. Cell-free glycation studies with bovine crystallins confirmed the results of the animals studies. Increasing glycation caused a corresponding increase in protein insolubilization and the insoluble fraction thus formed also contained more glycated protein. It appears that lens protein glycation, HMW aggregate formation, and protein insolubilization are interrelated

  15. In vitro uptake of 75Se-selenite by lens of young and adult rats

    International Nuclear Information System (INIS)

    Sladkova, J.; Ostadalova, I.; Babicky, A.; Obenberger, J.

    1988-01-01

    The uptake was observed of 75 Se-selenite by the lens in Wistar strain rats in adult animals, in 17-day old rats kept with their mothers and in prematurely weaned rats. Also measured was the excretion of 75 Se by the lens of young and adult rats following incubation in the medium with radioselenium. The metabolites were analysed which were discharged by the lens containing 75 Se. In Brattleboro rats the uptake of 75 Se-selenite was also measured by the lens in young and adult rats. The uptake of 75 Se-selenite by the lens in young Wistar rats was found to be 1.6 times higher than by the lens of adult rats and the time course of the radioselenium uptake was slightly different. In the lens of prematurely weaned rats no significant difference was found in the uptake of radioselenium after 4 hours as compared with rats of the same age kept with their mothers. In homozygous Brattleboro rats, a higher uptake of 75 Se-selenite was found as compared with both young and adult heterozygous rats. The time course and the quantity of 75 Se efflux from the lens of young and adult Wistar rats differed significantly after 0.5 hour of pre-incubation. From metabolites containing 75 Se excreted by the lens following preincubation, glutathione selenotrisulfide and a not yet accurately determined fraction with a large share of radioactivity were isolated. The stated results provide yet more proof that selenium cataract is a manifestation of the ontogenic dependence of selenium metabolism in the lens and in the entire organism. (author). 4 tabs., 30 refs

  16. Growth and optical development of the ocular lens of the squid (Sepioteuthis lessoniana).

    Science.gov (United States)

    Sivak, J G; West, J A; Campbell, M C

    1994-09-01

    Lens focal properties (spherical aberration), diameter and relative anterior/posterior proportions were measured photographically for Japanese squid (Sepioteuthis lessoniana) at ages 4-6 weeks, 7-9 weeks and 7-8 months. The measures involved photographing the refractive effects of lenses in a physiological solution, with and without an index matching fluid (polyvinylpyrroloidone solution), on a parallel array of fine helium-neon laser beams. Spherical aberration was determined from measurement of back vertex distance. Similar measurements were made on lenses from the eyes of cuttlefish (Sepia officinalis). The cephalopod lens develops as hemispheric halves from separate ectodermal sources. The posterior component contributes, on average, about 60% of axial lens diameter in S. lessoniana of all ages and 55% in S. officinalis. However, these proportions vary widely in both species. All lenses of both species show that spherical aberration is neutralized, although small variations in back vertex distance (positive and negative spherical aberration) were measured. Preliminary measures indicate that the refractive index distribution within the cephalopod lens varies in a manner reminiscent of teleost lenses. Squid lenses from animals 7-9 weeks of age were optimally corrected for spherical aberration. Some squid of this age, from a separate tank, showed a high incidence of cataract development. In each case, lens opacification was caused by deterioration of the posterior lens component.

  17. The hydrogeology of complex lens conditions in Qatar

    Science.gov (United States)

    Lloyd, J. W.; Pike, J. G.; Eccleston, B. L.; Chidley, T. R. E.

    1987-01-01

    The emirate of Qatar lies on a peninsula extending northward from the mainland of Saudi Arabia into the Arabian Gulf. The peninsula is underlain by sedimentary rocks ranging from late Cretaceous to Holocene age but only two Lower Tertiary units are identified as aquifers. The groundwater distribution in these units is seen to be controlled by facies distributions related to tectonically controlled sedimentation and subsequent dissolution. Dissolution has created permeability, in the Umm er Rhaduma limestones and in the overlying Rus anhydrites. In the latter case the dissolution has lead to extensive surface collapse which has provided a mechanism for recharge from runoff. Despite very low rainfall and high evaporation rates, recharge related to storm runoff has resulted in the establishment of a complex fresh groundwater lens in both aquifer units. The lens is constrained by saline groundwaters which in the lower unit are controlled by heads in eastern Saudi Arabia but in the upper unit by the Arabian Gulf sea level. Groundwater abstraction is shown to be distorting the fresh groundwater lens configuration, and estimates of the resultant flow responses affecting the lens are given.

  18. The Effect of the Crystalline Lens on Central Vault After Implantable Collamer Lens Implantation.

    Science.gov (United States)

    Qi, Meng-Ying; Chen, Qian; Zeng, Qing-Yan

    2017-08-01

    To identify associations between crystalline lens-related factors and central vault after Implantable Collamer Lens (ICL) (Staar Surgical, Monrovia, CA) implantation. This retrospective clinical study included 320 eyes from 186 patients who underwent ICL implantation surgery. At 1 year after surgery, the central vault was measured using anterior segment optical coherence tomography. Preoperative anterior chamber depth, lens thickness, lens position (lens position = anterior chamber depth + 1/2 lens thickness), and vault were analyzed to investigate the effects of lens-related factors on postoperative vault. The mean vault was 513 ± 215 µm at 1 year after surgery. Vault was positively correlated with preoperative anterior chamber depth (r = 0.495, P lens position (r = 0.371, P lens thickness (r = -0.262, P lens position than eyes in the other two vault groups (which had vaults ≥ 250 µm) (P lens position less than 5.1 mm had greatly reduced vaults (P lens could have an important influence on postoperative vault. Eyes with a shallower anterior chamber and a forward lens position will have lower vaults. [J Refract Surg. 2017;33(8):519-523.]. Copyright 2017, SLACK Incorporated.

  19. New results on nuclear multifragmentation in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies

    International Nuclear Information System (INIS)

    Besliu, Calin; Jipa, Alexandru; Iliescu, Bogdan; Felea, Daniel

    2002-01-01

    Some new aspects on the multifragmentation processes in nucleus-nucleus and nucleon-nucleus collisions at high energies are discussed in this work. Experimental data obtained in international collaborations (for example, MULTI Collaboration with KEK Tsukuba (Japan) and SKM 200 Collaboration with JINR Dubna (Russia)) are used to discuss new mechanisms in the target nucleus fragmentation. Correlations with stopping power, participant region size and energy density are included. Comparisons of the experimental results with the predictions of a phenomenological geometric model of intermediate mass fragment multiplicity, caloric curves and angular distributions are also presented. These results are used for global description of the multifragmentation processes in nucleon-nucleus and nucleus-nucleus collisions at relativistic energies. The size of the participant region and the average intermediate mass fragments multiplicity are taken into consideration using the free space probability. A few correlations between the deposited energy in the participant region and stability state of the intermediate mass fragments are presented in this work. The importance of the collision geometry in the multifragmentation processes is stressed. The results suggest different time moments for the incident nucleus fragmentation and for the target nucleus fragmentation. The associated entropies are distinct. (authors)

  20. DISSECTING THE GRAVITATIONAL LENS B1608+656. I. LENS POTENTIAL RECONSTRUCTION

    NARCIS (Netherlands)

    Suyu, S. H.; Marshall, P. J.; Blandford, R. D.; Fassnacht, C. D.; Koopmans, L. V. E.; McKean, J. P.; Treu, T.

    2009-01-01

    Strong gravitational lensing is a powerful technique for probing galaxy mass distributions and for measuring cosmological parameters. Lens systems with extended source-intensity distributions are particularly useful for this purpose since they provide additional constraints on the lens potential (

  1. Molecular orbitals of nucleons in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Imanishi, B.; Oertzen, W. von.

    1986-05-01

    A formalism for the dynamical treatment of the molecular orbitals of valence nucleons in nucleus-nucleus collisions at low bombarding energy is developed with the use of the coupled-reaction-channel (CRC) method. The Coriolis coupling effects as well as the finite mass effects of the nucleon are taken into account in this model, of rotating molecular orbitals, RMO. First, the validity of the concept is examined from the view point of the multi-step processes in a standard CRC calculation for systems containing two identical [core] nuclei. The calculations show strong CRC effects particularly in the case where the mixing of different l-parity orbitals - called hybridization in atomic physics - occurs. Then, the RMO representation for active nucleons is applied to the same systems and compared to the CRC results. Its validity is investigated with respect to the radial motion (adiabaticity) and the rotation of the molecular axis (radial and rotational coupling). Characteristic molecular orbitals of covalent molecules appear as rotationally stable states (K = 1/2) with good adiabaticity. Using the RMO's we obtain a new interpretation of various scattering phenomena. Dynamically induced changes in the effective Q-values (or scaling of energies), dynamically induced moments of inertia and an dynamically induced effective (L · S) interaction are obtained as a result of the molecular orbital formation. Various experimental data on transfer and subbarrier fusion reactions are understood in terms of the RMO's and their adiabatic potentials. Landau-Zener transitions, which strongly depend on the total angular momentum of the system, definitely predict the observation of characteristic changes in the cross sections for the inelastic scattering 13 C( 12 C, 12 C) 13 C* (3.086 MeV, 1/2 + ) with the change of the bombarding energy. (author)

  2. Growth of the human lens in the Indian adult population: Preliminary observations

    Directory of Open Access Journals (Sweden)

    Ashik Mohamed

    2012-01-01

    Full Text Available Context: The eye lens grows throughout life by the addition of new cells inside the surrounding capsule. How this growth affects the properties of the lens is essential for understanding disorders such as cataract and presbyopia. Aims: To examine growth of the human lens in the Indian population and compare this with the growth in Western populations by measuring in vitro dimensions together with wet and dry weights. Settings and Design: The study was conducted at the research wing of a tertiary eye care center in South India and the study design was prospective. Materials and Methods: Lenses were removed from eye bank eyes and their dimensions measured with a digital caliper. They were then carefully blotted dry and weighed before being placed in 5% buffered formalin. After 1 week fixation, the lenses were dried at 80 °C until constant weight was achieved. The constant weight was noted as the dry weight of the lens. Statistical Analysis Used: Lens parameters were analyzed as a function of age using linear and logarithmic regression methods. Results: Data were obtained for 251 lenses, aged 16-93 years, within a median postmortem time of 22 h. Both wet and dry weights increased linearly at 1.24 and 0.44 mg/year, respectively, throughout adult life. The dimensions also increased continuously throughout this time. Conclusions: Over the age range examined, lens growth in the Indian population is very similar to that in Western populations.

  3. Role of Aquaporin 0 in lens biomechanics

    International Nuclear Information System (INIS)

    Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G.; Menon, Anil G.; Mathias, Richard T.; Varadaraj, Kulandaiappan

    2015-01-01

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5 −/− ), AQP0 KO (heterozygous KO: AQP0 +/− ; homozygous KO: AQP0 −/− ; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0 +/− lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to

  4. Algorithm design of liquid lens inspection system

    Science.gov (United States)

    Hsieh, Lu-Lin; Wang, Chun-Chieh

    2008-08-01

    In mobile lens domain, the glass lens is often to be applied in high-resolution requirement situation; but the glass zoom lens needs to be collocated with movable machinery and voice-coil motor, which usually arises some space limits in minimum design. In high level molding component technology development, the appearance of liquid lens has become the focus of mobile phone and digital camera companies. The liquid lens sets with solid optical lens and driving circuit has replaced the original components. As a result, the volume requirement is decreased to merely 50% of the original design. Besides, with the high focus adjusting speed, low energy requirement, high durability, and low-cost manufacturing process, the liquid lens shows advantages in the competitive market. In the past, authors only need to inspect the scrape defect made by external force for the glass lens. As to the liquid lens, authors need to inspect the state of four different structural layers due to the different design and structure. In this paper, authors apply machine vision and digital image processing technology to administer inspections in the particular layer according to the needs of users. According to our experiment results, the algorithm proposed can automatically delete non-focus background, extract the region of interest, find out and analyze the defects efficiently in the particular layer. In the future, authors will combine the algorithm of the system with automatic-focus technology to implement the inside inspection based on the product inspective demands.

  5. Freeform lens design for LED collimating illumination.

    Science.gov (United States)

    Chen, Jin-Jia; Wang, Te-Yuan; Huang, Kuang-Lung; Liu, Te-Shu; Tsai, Ming-Da; Lin, Chin-Tang

    2012-05-07

    We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

  6. Cholesterol Bilayer Domains in the Eye Lens Health: A Review.

    Science.gov (United States)

    Widomska, Justyna; Subczynski, Witold K; Mainali, Laxman; Raguz, Marija

    2017-12-01

    The most unique biochemical characteristic of the eye lens fiber cell plasma membrane is its extremely high cholesterol content, the need for which is still unclear. It is evident, however, that the disturbance of Chol homeostasis may result in damages associated with cataracts. Electron paramagnetic resonance methods allow discrimination of two types of lipid domains in model membranes overloaded with Chol, namely, phospholipid-cholesterol domains and pure Chol bilayer domains. These domains are also detected in human lens lipid membranes prepared from the total lipids extracted from lens cortices and nuclei of donors from different age groups. Independent of the age-related changes in phospholipid composition, the physical properties of phospholipid-Chol domains remain the same for all age groups and are practically identical for cortical and nuclear membranes. The presence of Chol bilayer domains in these membranes provides a buffering capacity for cholesterol concentration in the surrounding phospholipid-Chol domains, keeping it at a constant saturating level and thus keeping the physical properties of the membrane consistent with and independent of changes in phospholipid composition. It seems that the presence of Chol bilayer domains plays an integral role in the regulation of cholesterol-dependent processes in fiber cell plasm membranes and in the maintenance of fiber cell membrane homeostasis.

  7. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. [Toshiba America Medical Systems (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  8. TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  9. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    International Nuclear Information System (INIS)

    Zhang, D.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  10. TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

    International Nuclear Information System (INIS)

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  11. Double folding model of nucleus-nucleus potential: formulae, iteration method and computer code

    International Nuclear Information System (INIS)

    Luk'yanov, K.V.

    2008-01-01

    Method of construction of the nucleus-nucleus double folding potential is described. Iteration procedure for the corresponding integral equation is presented. Computer code and numerical results are presented

  12. Study of various models of nuclear interaction potentials: nucleon-nucleus and nucleus-nucleus systems

    International Nuclear Information System (INIS)

    Ngo, H.

    1984-01-01

    Several models, performed within a mean field theory, are developed for the calculation of nucleon-nucleus interaction potentials. The first part of the thesis deals with the nucleon-nucleus average interaction. It is mainly devoted to the calculation of dynamical corrections to the Hartree-Fock approximation. Two approaches are used: a microscopic model performed in the framework of the nuclear structure approach and a semi-phenomenological one, based on the application of the dispersion relations to the empirical imaginary potential. Both models take into account finite size effects like collectivity or threshold effects which are important at low energy. The Green's function properties are used for both models. The second part of this work is devoted to the interaction potential between two heavy ions. This calculation, which is performed in the framework of the sudden approximation, uses the energy density formalism (Thomas-Fermi approximation). It has been extended to finite temperature. At T=0 the experimental fusion barriers of heavy systems are reproduced within 4%. Their temperature dependence is studied. The proximity scaling is checked and a universal function is obtained at T=0 and at finite temperature. It is found that the proximity theorem is well satisfied on the average. The dispersion around the mean behaviour increases with increasing temperature. At last, P+A* and α+A* interaction potentials are calculated within a double folding model using a schematic effective interaction [fr

  13. Altered morphology of the nucleus accumbens in persistent developmental stuttering.

    Science.gov (United States)

    Neef, Nicole E; Bütfering, Christoph; Auer, Tibor; Metzger, F Luise; Euler, Harald A; Frahm, Jens; Paulus, Walter; Sommer, Martin

    2018-03-01

    Neuroimaging studies in persistent developmental stuttering repeatedly report altered basal ganglia functions. Together with thalamus and cerebellum, these structures mediate sensorimotor functions and thus represent a plausible link between stuttering and neuroanatomy. However, stuttering is a complex, multifactorial disorder. Besides sensorimotor functions, emotional and social-motivational factors constitute major aspects of the disorder. Here, we investigated cortical and subcortical gray matter regions to study whether persistent developmental stuttering is also linked to alterations of limbic structures. The study included 33 right-handed participants who stutter and 34 right-handed control participants matched for sex, age, and education. Structural images were acquired using magnetic resonance imaging to estimate volumetric characteristics of the nucleus accumbens, hippocampus, amygdala, pallidum, putamen, caudate nucleus, and thalamus. Volumetric comparisons and vertex-based shape comparisons revealed structural differences. The right nucleus accumbens was larger in participants who stutter compared to controls. Recent theories of basal ganglia functions suggest that the nucleus accumbens is a motivation-to-movement interface. A speaker intends to reach communicative goals, but stuttering can derail these efforts. It is therefore highly plausible to find alterations in the motivation-to-movement interface in stuttering. While behavioral studies of stuttering sought to find links between the limbic and sensorimotor system, we provide the first neuroimaging evidence of alterations in the limbic system. Thus, our findings might initialize a unified neurobiological framework of persistent developmental stuttering that integrates sensorimotor and social-motivational neuroanatomical circuitries. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Changes in lens stiffness due to capsular opacification in accommodative lens refilling

    NARCIS (Netherlands)

    Nibourg, Lisanne M.; Sharma, Prashant K.; van Kooten, Theo G.; Koopmans, Steven A.

    Accommodation may be restored to presbyopic lenses by refilling the lens capsular bag with a soft polymer. After this accommodative lens refilling prevention of capsular opacification is a requirement, since capsular opacification leads to a decreased clarity of the refilled lens. It has been

  15. Exchange of tears under a contact lens is driven by distortions of the contact lens.

    Science.gov (United States)

    Maki, Kara L; Ross, David S

    2014-12-01

    We studied the flow of the post-lens tear film under a soft contact lens to understand how the design parameters of contact lenses can affect ocular health. When a soft contact lens is inserted, the blinking eyelid causes the lens to stretch in order to conform to the shape of the eye. The deformed contact lens acts to assume its un-deformed shape and thus generates a suction pressure in the post-lens tear film. In consequence, the post-lens tear fluid moves; it responds to the suction pressure. The suction pressure may draw in fresh fluid from the edge of the lens, or it may eject fluid there, as the lens reassumes its un-deformed shape. In this article, we develop a mathematical model of the flow of the post-lens tear fluid in response to the mechanical suction pressure of a deformed contact lens. We predict the amount of exchange of fluid exchange under a contact lens and we explore the influence of the eye's shape on the rate of exchange of fluid. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  16. Birc7: A Late Fiber Gene of the Crystalline Lens.

    Science.gov (United States)

    De Maria, Alicia; Bassnett, Steven

    2015-07-01

    A distinct subset of genes, so-called "late fiber genes," is expressed in cells bordering the central, organelle-free zone (OFZ) of the lens. The purpose of this study was to identify additional members of this group. Fiber cells were harvested from various layers of the lens by laser micro-dissection and subjected to microarray, in situ hybridization, and Western blot analysis. Expression of Livin, a member of the inhibitor of apoptosis protein (IAP) family encoded by Birc7, was strongly upregulated in deep cortical fiber cells. The depth-dependent distribution of Livin mRNA was confirmed by quantitative PCR and in situ hybridization. The onset of Livin expression coincided with loss of organelles from primary fiber cells. Livin expression peaked at 1 month but was sustained even in aged lenses. Antibodies raised against mouse Livin labeled multiple bands on immunoblots, reflecting progressive proteolysis of the parent molecule during differentiation. Mice harboring a floxed Birc7 allele were generated and used to conditionally delete Birc7 in lens. Lenses from knockout mice grew normally and retained their transparency, suggesting that Livin does not have an indispensable role in fiber cell differentiation. Birc7 is a late fiber gene of the mouse lens. In tumor cells, Livin acts as an antiapoptotic protein, but its function in the lens is enigmatic. Livin is a RING domain protein with putative E3 ubiquitin ligase activity. Its expression in cells bordering the OFZ is consistent with a role in organelle degradation, a process in which the ubiquitin proteasome pathway has been implicated previously.

  17. Optimized lens-sparing treatment of retinoblastoma with electron beams

    International Nuclear Information System (INIS)

    Steenbakkers, Roel J.H.M.; Altschuler, Martin D.; D'Angio, Giulio J.; Goldwein, Joel W.; Kassaee, Alireza

    1997-01-01

    Purpose: The ideal lens-sparing radiotherapy technique for retinoblastoma calls for 100% dose to the entire retina including the ora serrata and zero dose to the lens. Published techniques, most of which use photons, have not accomplished this ideal treatment. We describe here a technique that approaches this ideal configuration using electron beam therapy. Methods and Materials: Dose-modeling calculations were made using a computer program built around a proprietary algorithm. This program calculates 3D dose distribution for electrons and photons and uses the Cimmino feasibility method for the inverse problem of beam weighting to achieve the prescribed dose. The algorithm has been verified in the ocular region by measurements in a RANDO phantom. To search for an ideal lens-sparing beam setup, a stylized phantom of an 8-month-old infant was generated with built-in inhomogeneities, and a phantom of a 5-year-old child was generated from a patient CT series. Results: Of more than 100 different beam setups tested, two 9 MeV electron beams at gantry angles plus and minus 26 degrees from the optic nerve axis achieved the best distribution. Both fields have a lens block and an isocenter between the globe and origin of the optic nerve. When equal doses are given to both fields, the entire extent of the retina (including ora serrata) received 100%, while the lens received 10% or less. Conclusion: The two-oblique-electron-beam technique here described appears to meet most of the stringent dosimetry needed to treat retinoblastoma. It is suitable for a range of ages, from infancy to early childhood years

  18. Physical meaning of the yields from hadron-nucleon, hadron-nucleus, and nucleus-nucleus collisions observed in experiments

    International Nuclear Information System (INIS)

    Strugalski, Z.

    1995-01-01

    A physical meaning of the outcomes from hadronic and nuclear collision processes at high energies is presented, as prompted experimentally. The fast and slow stages in hadron-nucleus collisions are distinguished. Hadrons are produced via intermediate objects observed in hadron-nucleus collisions. The intermediate objects may be treated as the groups of quarks or the quark bags. 37 refs

  19. Lens design and local minima

    International Nuclear Information System (INIS)

    Brixner, B.

    1981-01-01

    The widespread belief that local minima exist in the least squares lens-design error function is not confirmed by the Los Alamos Scientific Laboratory (LASL) optimization program. LASL finds the optimum-mimimum region, which is characterized by small parameter gradients of similar size, small performance improvement per iteration, and many designs that give similar performance. Local minima and unique prescriptions have not been found in many-parameter problems. The reason for these absences is that image errors caused by a change in one parameter can be compensated by changes in the remaining parameters. False local minima have been found, and four cases are discussed

  20. Description of inelastic nucleus-nucleus interactions at medium energy using dual parton model

    International Nuclear Information System (INIS)

    Polanski, A.; Shmakov, S.Yu.; Uzhinskij, V.V.

    1989-01-01

    It is shown that the dual parton model taking into account the processes of diffraction dissociation to the low mass states and finite energy corrections to the asymptotic Abramovski-Gribov-Kancheli cutting rules allows satisfactory description of existing experimental data on hadron-nucleus and nucleus-nucleus interactions at medium energy. (orig.)

  1. Effects of wearing a daily disposable lens on tear film: a randomised controlled trial.

    Science.gov (United States)

    Chong, Pamela Qin Yi; Yeo, Sharon; Too, Cheah Loon; Boo, Cynthia; Tong, Louis

    2016-05-01

    Contact lens-induced dry eye is commonly encountered, although its extent is not well documented with daily disposable lenses. A novel type of contact lens system incorporating moisturising agent (alginic acid) has been developed. The aim of this study was to evaluate the effect of wearing daily 2-hydroxyethyl methacrylate disposable contact lenses for seven days on tear stability, conjunctival and limbal redness and dry eye symptoms. Then, we aimed to determine whether lens solutions containing alginic acid had any influence on tear parameters. This was a seven-day parallel group double-masked clinical trial of previous contact lens wearers, where participants were randomly assigned to wearing SEED 1dayPure moisture contact lenses with (n = 15) or without alginic acid (n = 15). Tear lipid layer thickness (LLT), non-invasive tear break-up time (NIBUT), conjunctival redness, corneal fluorescein staining, tear break-up time and Schirmer I readings were measured. Symptom severity and frequency were evaluated and combined using a global score from visual analogue scales. The mean age and standard deviation of the participants was 25 ± 3.8 years. There were 24 females and six males. After reintroduction of contact lens wear for one week, there was significant improvement in the global symptom score; however, this may not be clinically significant. There were small and clinically insignificant changes in limbal and conjunctival hyperaemia but no significant changes in lipid layer thickness, Schirmer I and NIBUT in overall participants. The use of alginic acid in lens solutions did not affect these parameters compared to control lenses (p > 0.05). After seven days of wearing a modern daily disposable lens, there was no significant deterioration of tear function in a group of young contact lens wearers. In this short-term study, there was no evidence of significant benefit of lens solutions containing alginic acid used with HEMA lenses. © 2016 The Authors Clinical and

  2. Primary anterior chamber intraocular lens for the treatment of severe crystalline lens subluxation.

    Science.gov (United States)

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2009-10-01

    Subluxated cataractous and clear lenses are commonly treated by limbal or pars plana lensectomy followed by primary or secondary intraocular lens (IOL) implantation. Adjunctive capsular prosthetic devices have facilitated lens removal and IOL centration in these challenging cases but have also added complexity and potential complications to the procedure. Although crystalline lens extraction may be required to clear the visual axis in mild to moderate lens subluxations, we propose insertion of a primary anterior chamber IOL without lens extraction in severe subluxations when the eye is optically aphakic or can be made functionally aphakic following neodymium:YAG laser zonulysis. Two cases demonstrating this approach are presented.

  3. Do migrating cells need a nucleus?

    Science.gov (United States)

    Hawkins, Rhoda J

    2018-03-05

    How the nucleus affects cell polarity and migration is unclear. In this issue, Graham et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201706097) show that enucleated cells polarize and migrate in two but not three dimensions and propose that the nucleus is a necessary component of the molecular clutch regulating normal mechanical responses. © 2018 Hawkins.

  4. Changes in the distribution of lens calcium during development of x-ray cataract

    International Nuclear Information System (INIS)

    Hightower, K.R.; Giblin, F.J.; Reddy, V.N.

    1983-01-01

    The present study was designed to examine the possible role of calcium in the opacification of x-ray-induced cataract in rabbit. The results demonstrate that the concentration of calcium in x-rayed lenses, just prior to lens hydration (7.5 weeks postirradiation), was twice that present in contralateral control lenses. At this stage of immature cataract, the lens nucleus remained transparent and maintained a normal level of calcium, but the lens cortex, containing regions of subcapsular opacification, accumulated a level of calcium that was twice that of the control. In the completely opaque mature cataract, (8-9 weeks post x-ray), both the cortex and nucleus had gained significant amounts of calcium. As the concentration of total calcium increased in the immature x-ray cataract, the amount of the cation bound to membranes and insoluble proteins of the cytosol also increased comparably. However, the relative proportion of calcium in the various fractions remained unaltered in the immature cataract; in both control lenses and immature cataracts, 20% of the total calcium remained in the membrane pellet and 70% was located in the soluble protein fraction. Only in the mature stage of cataract was a shift in the distribution of calcium apparent, as the proportion of calcium in the soluble protein fraction increased to 90%. Although only 7% of the total calcium in a mature cataract was bound to membrane, the amount represented a fivefold increase over the control. The results of this study demonstrate that an elevation in lens calcium accompanies the opacification process in x-ray cataract. The work also suggests that changes in calcium levels are not likely to result from inactivation of Ca-ATPase

  5. Fabricating customized hydrogel contact lens

    Science.gov (United States)

    Childs, Andre; Li, Hao; Lewittes, Daniella M.; Dong, Biqin; Liu, Wenzhong; Shu, Xiao; Sun, Cheng; Zhang, Hao F.

    2016-10-01

    Contact lenses are increasingly used in laboratories for in vivo animal retinal imaging and pre-clinical studies. The lens shapes often need modification to optimally fit corneas of individual test subjects. However, the choices from commercially available contact lenses are rather limited. Here, we report a flexible method to fabricate customized hydrogel contact lenses. We showed that the fabricated hydrogel is highly transparent, with refractive indices ranging from 1.42 to 1.45 in the spectra range from 400 nm to 800 nm. The Young’s modulus (1.47 MPa) and hydrophobicity (with a sessile drop contact angle of 40.5°) have also been characterized experimentally. Retinal imaging using optical coherence tomography in rats wearing our customized contact lenses has the quality comparable to the control case without the contact lens. Our method could significantly reduce the cost and the lead time for fabricating soft contact lenses with customized shapes, and benefit the laboratorial-used contact lenses in pre-clinical studies.

  6. Protection of the eye lens

    International Nuclear Information System (INIS)

    2015-01-01

    The limit of radiation exposure for eye lens is going to decrease dramatically from 150 to 20 mSv as a transposition into the French law of a CIPR (International Commission for Radiation Protection) directive. Sanitary studies have shown that radiologists are more likely by a factor of 3.8 to get eye lens opacities than the rest of the population. The wearing of protective glasses is recommended and in order to get a better monitoring of the radiation dose new dosimeters have been designed, they can be worn on the glass frame of directly stuck on the skin near the eyes. A study has shown that veterinary surgeons that are accustomed to stay near animals to keep them quiet during radiological exams are prone to receive high doses as well as physicians that use hypnosis to decrease the level of anxiety of their patients during radiological exams. Radiation exposure of radiologists can be mitigated through: the use of protective shields and equipment and the optimization of the dose delivered to the patient. (A.C.)

  7. Serotonin projection patterns to the cochlear nucleus.

    Science.gov (United States)

    Thompson, A M; Thompson, G C

    2001-07-13

    The cochlear nucleus is well known as an obligatory relay center for primary auditory nerve fibers. Perhaps not so well known is the neural input to the cochlear nucleus from cells containing serotonin that reside near the midline in the midbrain raphe region. Although the specific locations of the main, if not sole, sources of serotonin within the dorsal cochlear nucleus subdivision are known to be the dorsal and median raphe nuclei, sources of serotonin located within other cochlear nucleus subdivisions are not currently known. Anterograde tract tracing was used to label fibers originating from the dorsal and median raphe nuclei while fluorescence immunohistochemistry was used to simultaneously label specific serotonin fibers in cat. Biotinylated dextran amine was injected into the dorsal and median raphe nuclei and was visualized with Texas Red, while serotonin was visualized with fluorescein. Thus, double-labeled fibers were unequivocally identified as serotoninergic and originating from one of the labeled neurons within the dorsal and median raphe nuclei. Double-labeled fiber segments, typically of fine caliber with oval varicosities, were observed in many areas of the cochlear nucleus. They were found in the molecular layer of the dorsal cochlear nucleus, in the small cell cap region, and in the granule cell and external regions of the cochlear nuclei, bilaterally, of all cats. However, the density of these double-labeled fiber segments varied considerably depending upon the exact region in which they were found. Fiber segments were most dense in the dorsal cochlear nucleus (especially in the molecular layer) and the large spherical cell area of the anteroventral cochlear nucleus; they were moderately dense in the small cell cap region; and fiber segments were least dense in the octopus and multipolar cell regions of the posteroventral cochlear nucleus. Because of the presence of labeled fiber segments in subdivisions of the cochlear nucleus other than the

  8. Actomyosin contractility rotates the cell nucleus.

    Science.gov (United States)

    Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G V

    2014-01-21

    The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells.

  9. Color corrected Fresnel lens for solar concentration

    International Nuclear Information System (INIS)

    Kritchman, E.M.

    1979-01-01

    A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

  10. Analysis of a Thin Optical Lens Model

    Science.gov (United States)

    Ivchenko, Vladimir V.

    2011-01-01

    In this article a thin optical lens model is considered. It is shown that the limits of its applicability are determined not only by the ratio between the thickness of the lens and the modules of the radii of curvature, but above all its geometric type. We have derived the analytical criteria for the applicability of the model for different types…

  11. Mathematical Lens: How Much Can You Bench?

    Science.gov (United States)

    Bolognese, Chris A.

    2013-01-01

    "How Much Can You Bench?" appears in the "Mathematical Lens" section of "Mathematics Teacher." "Mathematical Lens" uses photographs as a springboard for mathematical inquiry and appears in every issue of "Mathematics Teacher." This month the mathematics behind the photograph includes finding areas…

  12. Plasma Lens for Muon and Neutrino Beams

    International Nuclear Information System (INIS)

    Kahn, S.A.; Korenev, S.; Bishai, M.; Diwan, M.; Gallardo, J.C.; Hershcovitch, A.; Johnson, B.M.

    2008-01-01

    The plasma lens is examined as an alternate to focusing horns and solenoids for use in a neutrino or muon beam facility. The plasma lens concept is based on a combined high-energy lens/target configuration. The current is fed at electrodes located upstream and downstream from the target where pion capturing is needed. The current flows primarily in the plasma, which has a lower resistivity than the target. A second plasma lens section, with an additional current feed, follows the target to provide shaping of the plasma for optimum focusing. The plasma lens is immersed in an additional solenoid magnetic field to facilitate the plasma stability. The geometry of the plasma is shaped to provide optimal pion capture. Simulations of this plasma lens system have shown a 25% higher neutrino production than the horn system. Plasma lenses have the additional advantage of negligible pion absorption and scattering by the lens material and reduced neutrino contamination during anti-neutrino running. Results of particle simulations using plasma lens will be presented

  13. Exome Array Analysis of Nuclear Lens Opacity.

    Science.gov (United States)

    Loomis, Stephanie J; Klein, Alison P; Lee, Kristine E; Chen, Fei; Bomotti, Samantha; Truitt, Barbara; Iyengar, Sudha K; Klein, Ronald; Klein, Barbara E K; Duggal, Priya

    2018-06-01

    Nuclear cataract is the most common subtype of age-related cataract, the leading cause of blindness worldwide. It results from advanced nuclear sclerosis, or opacity in the center of the optic lens, and is affected by both genetic and environmental risk factors, including smoking. We sought to understand the genetic factors associated with nuclear sclerosis through interrogation of rare and low frequency coding variants using exome array data. We analyzed Illumina Human Exome Array data for 1,488 participants of European ancestry in the Beaver Dam Eye Study who were without cataract surgery for association with nuclear sclerosis grade, controlling for age and sex. We performed single-variant regression analysis for 32,138 variants with minor allele frequency (MAF) ≥0.003. In addition, gene-based analysis of 11,844 genes containing at least two variants with MAF nuclear sclerosis, the possible association with the RNF149 gene highlights a potential candidate gene for future studies that aim to understand the genetic architecture of nuclear sclerosis.

  14. LensEnt2: Maximum-entropy weak lens reconstruction

    Science.gov (United States)

    Marshall, P. J.; Hobson, M. P.; Gull, S. F.; Bridle, S. L.

    2013-08-01

    LensEnt2 is a maximum entropy reconstructor of weak lensing mass maps. The method takes each galaxy shape as an independent estimator of the reduced shear field and incorporates an intrinsic smoothness, determined by Bayesian methods, into the reconstruction. The uncertainties from both the intrinsic distribution of galaxy shapes and galaxy shape estimation are carried through to the final mass reconstruction, and the mass within arbitrarily shaped apertures are calculated with corresponding uncertainties. The input is a galaxy ellipticity catalog with each measured galaxy shape treated as a noisy tracer of the reduced shear field, which is inferred on a fine pixel grid assuming positivity, and smoothness on scales of w arcsec where w is an input parameter. The ICF width w can be chosen by computing the evidence for it.

  15. Classical gluon production amplitude for nucleus-nucleus collisions:First saturation correction in the projectile

    International Nuclear Information System (INIS)

    Chirilli, Giovanni A.; Kovchegov, Yuri V.; Wertepny, Douglas E.

    2015-01-01

    We calculate the classical single-gluon production amplitude in nucleus-nucleus collisions including the first saturation correction in one of the nuclei (the projectile) while keeping multiple-rescattering (saturation) corrections to all orders in the other nucleus (the target). In our approximation only two nucleons interact in the projectile nucleus: the single-gluon production amplitude we calculate is order-g"3 and is leading-order in the atomic number of the projectile, while resumming all order-one saturation corrections in the target nucleus. Our result is the first step towards obtaining an analytic expression for the first projectile saturation correction to the gluon production cross section in nucleus-nucleus collisions.

  16. Treatment, material, care, and patient-related factors in contact lens-related dry eye.

    Science.gov (United States)

    Ramamoorthy, Padmapriya; Sinnott, Loraine T; Nichols, Jason J

    2008-08-01

    To examine the effect of general contact lens and material characteristics, care solutions, treatment, and patient-related factors on contact lens-related dry eye. The data were derived from the Contact Lens and Dry Eye Study, designed as a cross-sectional and nested case-control study including 360 subjects. In separate statistical models, logistic regression was used to examine general contact lens characteristics, specific hydrogel lens materials, care solutions, and patient-related factors associated with dry eye status (controlled for age, gender, and current treatments). Several factors were significantly associated with dry eye, including treatment factors such as a recent contact lens refitting (odds ratios [OR] = 5.75, 95% confidence intervals [CI] = 2.14 to 15.46) and use of artificial tears/rewetting drops (OR = 1.09, 95% CI = 1.02 to 1.16), in addition, currently worn materials including Food and Drug Administration (FDA) group II (OR = 2.98, 95% CI = 1.14 to 6.19) and IV (OR = 1.87, 95% CI = 1.08 to 3.24). Significant patient-related factors included decreased overall satisfaction (OR = 3.57, 95% CI = 2.08 to 5.88,), dry eye in the absence of contact lens wear (OR = 6.54, 95% CI = 2.57 to 16.62), reduced daily lens wear duration (OR = 1.16, 95% CI = 1.06 to 1.26), and reduced ability to wear lenses as long as desired (OR = 2.44, 95% CI = 1.30 to 4.54). Care solutions were not associated with contact lens-related dry eye. The strong association of common treatment factors with dry eye status in contact lens wearers suggests that these treatments are not entirely effective. The use of high water content materials was strongly related to dry eye in lens wearers, whereas care solutions were not. Contact lens-related dry eye was also associated with several patient-related factors such as greater ocular discomfort (without lenses), dissatisfaction, and inability to wear lenses for desired durations.

  17. Strangeness production in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions in the dual parton model

    International Nuclear Information System (INIS)

    Moehring, H.; Ranft, J.; Capella, A.; Tran Thanh Van, J.

    1993-01-01

    Λ, bar Λ, and K S 0 production is studied in a Monte Carlo dual parton model for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions with an SU(3) symmetric sea for chain formation (chain ends) but strangeness suppression in the chain fragmentation process. Additionally, (qq)-(bar q bar q) production from the sea was introduced into the chain formation process with the same probability as for the q→qq branching within the chain decay process. With these assumptions, multiplicity ratios and Feynman-x distributions for strange particles in h-h and multiplicity ratios in heavy ion collisions are reasonably well reproduced

  18. Radiation Dose to the Lens of the Eye from Computed Tomography Scans of the Head

    Science.gov (United States)

    Januzis, Natalie Ann

    While it is well known that exposure to radiation can result in cataract formation, questions still remain about the presence of a dose threshold in radiation cataractogenesis. Since the exposure history from diagnostic CT exams is well documented in a patient's medical record, the population of patients chronically exposed to radiation from head CT exams may be an interesting area to explore for further research in this area. However, there are some challenges in estimating lens dose from head CT exams. An accurate lens dosimetry model would have to account for differences in imaging protocols, differences in head size, and the use of any dose reduction methods. The overall objective of this dissertation was to develop a comprehensive method to estimate radiation dose to the lens of the eye for patients receiving CT scans of the head. This research is comprised of a physics component, in which a lens dosimetry model was derived for head CT, and a clinical component, which involved the application of that dosimetry model to patient data. The physics component includes experiments related to the physical measurement of the radiation dose to the lens by various types of dosimeters placed within anthropomorphic phantoms. These dosimeters include high-sensitivity MOSFETs, TLDs, and radiochromic film. The six anthropomorphic phantoms used in these experiments range in age from newborn to adult. First, the lens dose from five clinically relevant head CT protocols was measured in the anthropomorphic phantoms with MOSFET dosimeters on two state-of-the-art CT scanners. The volume CT dose index (CTDIvol), which is a standard CT output index, was compared to the measured lens doses. Phantom age-specific CTDIvol-to-lens dose conversion factors were derived using linear regression analysis. Since head size can vary among individuals of the same age, a method was derived to estimate the CTDIvol-to-lens dose conversion factor using the effective head diameter. These conversion

  19. Laser spectroscopy probes the nucleus

    International Nuclear Information System (INIS)

    Griffith, J.; Billowes, J.

    1998-01-01

    Extremely sensitive optical measurements are shedding new light on the shape and size of nuclei, and the properties of nuclear matter far from stability. Of the 7000 or so isotopes known to nuclear physicists, less than 270 are stable. In general isotopes become more and more unstable as we move away from the so-called valley of stability, and therefore become more difficult to study in experiments. The tests of the theory also become more demanding. Laser spectroscopy is one of the techniques that is helping to explore the properties of these isotopes and improve our understanding of the forces inside the nucleus. High-resolution laser spectroscopy of short-lived radioactive atoms now makes it possible to measure the nuclear charge radius of many elements, including many isotopes far from stability. The method can reveal fine details of the sizes, shapes and structures of nuclei. In addition, laser spectroscopy is making significant contributions to our understanding of the nuclear force in unstable nuclei with unusual, or extreme, proton-neutron ratios. In this article the authors discuss the latest advances in studying heavy nuclei. (author)

  20. Music and the nucleus accumbens.

    Science.gov (United States)

    Mavridis, Ioannis N

    2015-03-01

    Music is a universal feature of human societies over time, mainly because it allows expression and regulation of strong emotions, thus influencing moods and evoking pleasure. The nucleus accumbens (NA), the most important pleasure center of the human brain (dominates the reward system), is the 'king of neurosciences' and dopamine (DA) can be rightfully considered as its 'crown' due to the fundamental role that this neurotransmitter plays in the brain's reward system. Purpose of this article was to review the existing literature regarding the relation between music and the NA. Studies have shown that reward value for music can be coded by activity levels in the NA, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. Listening to music strongly modulates activity in a network of mesolimbic structures involved in reward processing including the NA. The functional connectivity between brain regions mediating reward, autonomic and cognitive processing provides insight into understanding why listening to music is one of the most rewarding and pleasurable human experiences. Musical stimuli can significantly increase extracellular DA levels in the NA. NA DA and serotonin were found significantly higher in animals exposed to music. Finally, passive listening to unfamiliar although liked music showed activations in the NA.

  1. A study of corneal endothelial changes in soft contact lens wearers using non-contact specular microscopy

    Directory of Open Access Journals (Sweden)

    Renu M Magdum

    2013-01-01

    Full Text Available Aim: To study the corneal endothelial changes after soft contact lens wear, to correlate these changes with the duration of soft contact lens wear, and to study the pattern of use and preferences of contact lens among young adults. Materials and Methods: This observational study was carried out in 100 eyes of 50 soft contact lens users aged between 19 and 27 years. Both eyes of 50 medical students who had never worn contact lenses served as controls. Data from each subject were collected using a structured questionnaire of 24 items that included demographic profile, pattern of contact lens use, symptoms, brand name, number of years worn, and hours of daily wear. These data were analyzed using Chi square for association. Specular microscopy was done using TOPCON SP-3000P. Computerized morphometry was used to evaluate central corneal thickness, size, shape, mean cellular density, hexagonality, coefficient of variation, and polymegathism of the corneal cells . Results: It was found that central corneal thickness was 0.532 ± 0.0309 mm in lens users and 0.514 ± 0.03 mm in controls, cell density was 2570.91 ± 432.06 cells/mm 2 in lens users and 2723.17 ± 327.64 cells/mm 2 in controls, while hexagonality was 54.81 ± 39.72% in lens users and 67.65 ± 36.49% in controls. Conclusion: Despite the known effects of long duration of soft contact lens use on corneal endothelial cell morphology, this study could not draw a significant correlation between them. However, a significant difference was found in the corneal endothelial thickness, cell density, and hexagonality. Among the soft contact lens users, 62% used soft disposable type while 38% used soft extended wear contact lens. Contact lenses were preferred over spectacles for better cosmetic appearance, comfort, and wider visual field.

  2. [Comparative analysis of visual function and the quality of life index with eyeglasses or a progressive contact lens].

    Science.gov (United States)

    Sant'Anna, Neusa Vidal; Schor, Paulo; Lipener, César; Uras, Ricardo

    2006-01-01

    To compare the visual function and the answers to a questionnaire of quality of life of patients wearing a progressive contact lens or eyeglasses. The Focus Progressive contact lens had been fitted in 35 patients with far visual acuity with progressive-addition eyeglasses equal to zero (log MAR) and near J1 (Jaeger). The far and near visual acuities and the measurement of contrast sensitivity were compared when the patients were wearing the eyeglasses or the contact lens and the patients' results of the scores of the quality of life questionnaire (NEI VFQ-25) were analyzed statistically considering the type of ametropy and the age. The far and near visual acuities and the contrast sensitivity measurement were worse with the contact lens than with eyeglasses. The answers to the questionnaire did not differ when were comparing the same patients wearing eyeglasses or contact lens, no matter the type of ametropy. The myopic and the hyperopic subgroups had worse answers to the quality of life questionnaire when corrected with the contact lens than with eyeglasses, both with age equal to or less than their median. The visual function was worse with the contact lens. The type of ametropy did not influence the answers to the quality of life questionnaire considering the optical correction, but age did.

  3. Lessons learned: wrong intraocular lens.

    Science.gov (United States)

    Schein, Oliver D; Banta, James T; Chen, Teresa C; Pritzker, Scott; Schachat, Andrew P

    2012-10-01

    To report cases involving the placement of the wrong intraocular lens (IOL) at the time of cataract surgery where human error occurred. Retrospective small case series, convenience sample. Seven surgical cases. Institutional review of errors committed and subsequent improvements to clinical protocols. Lessons learned and changes in procedures adapted. The pathways to a wrong IOL are many but largely reflect some combination of poor surgical team communication, transcription error, lack of preoperative clarity in surgical planning or failure to match the patient, and IOL calculation sheet with 2 unique identifiers. Safety in surgery involving IOLs is enhanced both by strict procedures, such as an IOL-specific "time-out," and the fostering of a surgical team culture in which all members are encouraged to voice questions and concerns. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  4. Radiation studies in Lens culinaris

    International Nuclear Information System (INIS)

    Sinha, S.S.N.

    1977-01-01

    Estimation of chromosomal aberrations in flowers of Lens culinaris according to their sequence of development in the plants at 4, 8 and 12 Kr in the M 1 generation, showed that the later formed flowers had smaller percentages of cells with aberrations than those developed earlier. It is suggested that this may be the result of competition between more damaged and less damaged cells during the development of the shoot. There is consequently a decrease of sterility in successive flowers. The numbers of karyotypes taking part in the formation of lower and uppermost flowers were estimated cytologically at 4, 8 and 12 Kr. It was found that more karyotypes were involved in the formation of the lower flowers than in the upper ones. It appeared that at lower doses larger numbers of karyotypes were taking part in the formation of the chimaera than at higher doses. (auth.)

  5. Immunoglobulin Concentration in Tears of Contact Lens Wearers

    Science.gov (United States)

    Maurya, Rajendra P.; Bhushan, Prashant; Singh, Virendra P.; Singh, Mahendra K.; Kumar, Prakash; Bhatia, Ravindra P.S.; Singh, Usha

    2014-01-01

    Purpose: To evaluate changes in the concentration of tear immunoglobulins in contact lens wearers. Methods: A total of 45 cases including 23 contact lens wearers (43 eyes) and 22 age and sex matched healthy controls having no ocular pathology were studied for immunoglobulins (IgA, IgG, IgM) in their tears by single radial immunodiffusion method. Results: Most of the cases used soft (56.6%) and semi-soft gas permeable (30.4%) contact lenses. Tear IgM was detected in only 17.4% and tear IgG in 43.6% of contact lens wearers, while in controls IgG was detected in 9.1% but none of the controls had IgM. There was a significant rise in total tear IgA (13.17 ± 4.44 mg/dl) in contact lens wearer as compared to controls (8.93 ± 3.79 mg/dl). Rise of tear IgA was more in symptomatic patients (15.38 ± 5.28 mg/dl) and in those wearing hard (19.73 ± 5.43 mg/dl) and semi-soft contact lenses (13.31 ± 5.43 mg/dl). A significant increase in tear IgA was noticed in subjects wearing lenses for >3 years (15.69 ± 5.39 mg/dl). About 43.4% of lens wearers were symptomatic and 80% of their lenses showed deposits and/or haziness. All cases with IgM in tear were symptomatic. Conclusion: The relation of immunoglobulin concentration with increasing duration of wear and material of contact lens shows that tear immunoglobulin rise accrues due to mechanical stimulation, hence contact lenses should not be used for a long period and lenses of hard nature should be discouraged. The maintenance, cleaning and deproteinization of the lenses are of high importance to avoid immunostimulation. PMID:25667732

  6. Partial inelasticity coefficients of negative pions produced in hadron-nucleus and nucleus-nucleus collisions at high energies

    International Nuclear Information System (INIS)

    OLIMOV, K.; LUTPULLAEV, S.L.; PETROV, V.I.; OLIMOV, A.K.

    2015-01-01

    New experimental data on the partial inelasticity coefficients of negative pions produced in "1"6Op-collisions at 3.25 A GeV/s, pC-interactions at 4.2 and 9.9 GeV/s, and d,α,C(C)-collisions at 4.2 A GeV/s are presented. It is established that the behavior of partial inelasticity coefficients of pions at intermediate energies (<10 GeV) in hadron-nucleus collisions has a transitional character, reaching the limiting value at ultrahigh energies. It is shown that the mean values of partial inelasticity coefficients of pions produced in nucleus-nucleus collisions decrease with an increase in mass number of the projectile nucleus. (authors)

  7. Neutrino-nucleus collision at intermediate energy

    International Nuclear Information System (INIS)

    Kosmas, T.S.; Oset, E.

    1999-01-01

    Neutrino-nucleus reactions at low and intermediate energy up to E ν = 500 MeV are studied for the most interesting nuclei from an experimental point of view. We focus on neutrino-nucleus cross-sections of semi-inclusive processes, for which recent measurements from radiochemical experiments at LAMPF and KARMEN laboratories are available. The method employed uses the modified Lindhard function for the description of the particle-hole excitations of the final nucleus via a local density approximation. (authors)

  8. Precision lens assembly with alignment turning system

    Science.gov (United States)

    Ho, Cheng-Fang; Huang, Chien-Yao; Lin, Yi-Hao; Kuo, Hui-Jean; Kuo, Ching-Hsiang; Hsu, Wei-Yao; Chen, Fong-Zhi

    2017-10-01

    The poker chip assembly with high precision lens barrels is widely applied to ultra-high performance optical system. ITRC applies the poker chip assembly technology to the high numerical aperture objective lenses and lithography projection lenses because of its high efficiency assembly process. In order to achieve high precision lens cell for poker chip assembly, an alignment turning system (ATS) is developed. The ATS includes measurement, alignment and turning modules. The measurement module is equipped with a non-contact displacement sensor (NCDS) and an autocollimator (ACM). The NCDS and ACM are used to measure centration errors of the top and the bottom surface of a lens respectively; then the amount of adjustment of displacement and tilt with respect to the rotational axis of the turning machine for the alignment module can be determined. After measurement, alignment and turning processes on the ATS, the centration error of a lens cell with 200 mm in diameter can be controlled within 10 arcsec. Furthermore, a poker chip assembly lens cell with three sub-cells is demonstrated, each sub-cells are measured and accomplished with alignment and turning processes. The lens assembly test for five times by each three technicians; the average transmission centration error of assembly lens is 12.45 arcsec. The results show that ATS can achieve high assembly efficiency for precision optical systems.

  9. Bioinspired adaptive gradient refractive index distribution lens

    Science.gov (United States)

    Yin, Kezhen; Lai, Chuan-Yar; Wang, Jia; Ji, Shanzuo; Aldridge, James; Feng, Jingxing; Olah, Andrew; Baer, Eric; Ponting, Michael

    2018-02-01

    Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. An adaptive GRIN lens was fabricated from a laminated stack of the variable refractive index films with a 0.05 spherical GRIN. This lens was subsequently deformed by mechanical ring compression of the lens. Variation in the optical properties of the deformable GRIN lens was determined, including 20% variation in focal length and reduced spherical aberration. These properties were measured and compared to simulated results by placido-cone topography and ANSYS methods. The demonstration of a solid-state, dynamic focal length, GRIN lens with improved aberration correction was discussed relative to the potential future use in implantable devices.

  10. Four-year Follow-up of the Changes in Anterior Segment After Phakic Collamer Lens Implantation.

    Science.gov (United States)

    Lu, Yuanyuan; Yang, Na; Li, Xuedong; Kong, Jun

    2017-06-01

    To assess the changes and relationship in central vaulting, flare intensity, and crystalline lens thickness during a follow-up period of 4 years after implantable collamer lens (ICL) implantation in eyes with high myopia. Retrospective observational study. Ninety-eight eyes of 50 patients were followed up with routine measurements of central vaulting, crystalline lens thickness, endothelial cell density, and aqueous flare postoperatively. Data were analyzed by repeated-measures analysis of variance. The relationship between the annual change in crystal lens thickness after surgery and age was evaluated by Pearson correlation coefficient and linear regression. There was a continuous reduction in central vaulting and endothelial cell density as well as an increase in crystalline lens thickness in ICL eyes from 1 month onward to 5 years postoperatively (P lens thickness (r = 0.617, P lens thickness are more prominent during the first year after ICL implantation, tending to be relatively stable afterwards. The anterior inflammation during the early postoperative period synchronizes with the sharp progression of crystalline lens changes within the first year. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. The application of a phenomenological model to inelastic nucleus-nucleus interactions for laboratory momenta below 5 GeV/c per nucleon of the incident nucleus

    International Nuclear Information System (INIS)

    Grishin, V.G.; Kladnitskaya, E.N.

    1985-01-01

    A phenomenological model for inelastic nucleus-nucleus interactions at momenta below 5 GeV/c per nucleon is described. Particle interactions inside the interacting nuclei are described by phenomenological models of hadron-nucleus and hadron-nucleon interactions. The Monte-Carlo model provides the kinematic variables for a set of events under study. The comparison of the model inclusive distri-- butions for different particles and nucleus-nucleus interactions agrees well with the experimental data

  12. Study of Hadron Production in Hadron-Nucleus and Nucleus-Nucleus Collisions at the CERN SPS

    CERN Multimedia

    Klochkov, V; Herve, A E; Kowalski, S; Kaptur, E A; Kowalik, K L; Dominik, W M; Matulewicz, T N; Krasnoperov, A; Feofilov, G; Vinogradov, L; Kovalenko, V; Johnson, S R; Planeta, R J; Rubbia, A; Marton, K; Messerly, B A; Puzovic, J; Bogomilov, M V; Bravar, A; Renfordt, R A E; Deveaux, M; Engel, R R; Grzeszczuk, A; Davis, N; Kuich, M; Lyubushkin, V; Kondratev, V; Kadija, K; Diakonos, F; Slodkowski, M A; Rauch, W H; Pistillo, C; Laszlo, A; Nakadaira, T; Hasegawa, T; Sadovskiy, A; Morozov, S; Petukhov, O; Mathes, H; Roehrich, D; Marcinek, A J; Marino, A D; Grebieszkow, K; Di luise, S; Wlodarczyk, Z; Rybczynski, M A; Wojtaszek-szwarc, A; Nirkko, M C; Sakashita, K; Golubeva, M; Kurepin, A; Manic, D; Kolev, D I; Kisiel, J E; Koziel, M E; Rondio, E; Larsen, D T; Czopowicz, T R; Seyboth, P; Turko, L; Guber, F; Marin, V; Busygina, O; Strikhanov, M; Taranenko, A; Cirkovic, M; Roth, M A; Pulawski, S M; Aduszkiewicz, A M; Bunyatov, S; Vechernin, V; Nagai, Y; Anticic, T; Dynowski, K M; Mackowiak-pawlowska, M K; Stefanek, G; Pavin, M; Fodor, Z P; Nishikawa, K; Tada, M; Blondel, A P P; Stroebele, H W; Posiadala, M Z; Kolesnikov, V; Andronov, E; Zimmerman, E D; Antoniou, N; Majka, Z; Dumarchez, J; Naskret, M; Ivashkin, A; Tsenov, R V; Koziel, M G; Schmidt, K J; Melkumov, G; Popov, B; Panagiotou, A; Richter-was, E M; Morgala, S J; Paolone, V; Damyanova, A; Gazdzicki, M; Unger, M T; Wilczek, A G; Stepaniak, J M; Seryakov, A; Susa, T; Staszel, P P; Brzychczyk, J; Maksiak, B; Tefelski, D B

    2007-01-01

    The NA61/SHINE (SHINE = SPS Heavy Ion and Neutrino Experiment) experiment is a large acceptance hadron spectrometer at the CERN SPS for the study of the hadronic final states produced in interactions of various beam particles (pions, protons, C, S and In) with a variety of fixed targets at the SPS energies. The main components of the current detector were constructed and used by the NA49 experiment. The physics program of NA61/SHINE consists of three main subjects. In the first stage of data taking (2007-2009) measurements of hadron production in hadron-nucleus interactions needed for neutrino (T2K) and cosmic-ray (Pierre Auger and KASCADE) experiments will be performed. In the second stage (2009-2011) hadron production in proton-proton and proton-nucleus interactions needed as reference data for a better understanding of nucleus-nucleus reactions will be studied. In the third stage (2009-2013) energy dependence of hadron production properties will be measured in nucleus-nucleus collisions as well as in p+p a...

  13. The role of macromolecular crowding in the evolution of lens crystallins with high molecular refractive index

    International Nuclear Information System (INIS)

    Zhao, Huaying; Magone, M Teresa; Schuck, Peter

    2011-01-01

    Crystallins are present in the lens at extremely high concentrations in order to provide transparency and generate a high refractive power of the lens. The crystallin families prevalent in the highest density lens tissues are γ-crystallins in vertebrates and S-crystallins in cephalopods. As shown elsewhere, in parallel evolution, both have evolved molecular refractive index increments 5–10% above those of most proteins. Although this is a small increase, it is statistically very significant and can be achieved only by very unusual amino acid compositions. In contrast, such a molecular adaptation to aid in the refractive function of the lens did not occur in crystallins that are preferentially located in lower density lens tissues, such as vertebrate α-crystallin and taxon-specific crystallins. In the current work, we apply a model of non-interacting hard spheres to examine the thermodynamic contributions of volume exclusion at lenticular protein concentrations. We show that the small concentration decrease afforded by the higher molecular refractive index increment of crystallins can amplify nonlinearly to produce order of magnitude differences in chemical activities, and lead to reduced osmotic pressure and the reduced propensity for protein aggregation. Quantitatively, this amplification sets in only at protein concentrations as high as those found in hard lenses or the nucleus of soft lenses, in good correspondence to the observed crystallin properties in different tissues and different species. This suggests that volume exclusion effects provide the evolutionary driving force for the unusual refractive properties and the unusual amino acid compositions of γ-crystallins and S-crystallins

  14. Design of a hyperbolic microwave metallic lens

    International Nuclear Information System (INIS)

    Uckan, T.

    1979-12-01

    Due to problems caused by multiple reflections in the cavity walls of the EBT fusion research device, the use of a horn becomes important for the directivity of waves in the millimetric range. An ordinary dielectric lens cannot be used because of plasma-wall interactions. Microwave metallic lenses, designed to focus the energy into a plane wave, can improve the directivity considerably. By implementing a 70-GHz standard-gain horn with a delay-type hyperbolic lens, which consists of a solid metallic disk with a number of equal size small holes has indicated a gain of 15 dB over the no lens case

  15. Accelerating convergence in automatic lens design

    International Nuclear Information System (INIS)

    Brixner, B.

    1981-01-01

    Among the various factors that slow lens optimization-insufficient performance targets, the absence of a unique solution, false local minima, a poorly scaled change vector, failure to find the optimum damping number, and failure to equalize the parameter gradients-the importance of parameter gradient equalization has been insufficiently recognized. Gradients can be approximately equalized by scaling the lens to a suitable size while it is being optimized. For best results, the size of the damping number should also be optimized during each iteration. If these two procedures are followed, scaling the change vector is usually not crucial. To illustrate the importance of parameter equalization, a lens optimization is analyzed

  16. Semiautomated analysis of optical coherence tomography crystalline lens images under simulated accommodation.

    Science.gov (United States)

    Kim, Eon; Ehrmann, Klaus; Uhlhorn, Stephen; Borja, David; Arrieta-Quintero, Esdras; Parel, Jean-Marie

    2011-05-01

    Presbyopia is an age related, gradual loss of accommodation, mainly due to changes in the crystalline lens. As part of research efforts to understand and cure this condition, ex vivo, cross-sectional optical coherence tomography images of crystalline lenses were obtained by using the Ex-Vivo Accommodation Simulator (EVAS II) instrument and analyzed to extract their physical and optical properties. Various filters and edge detection methods were applied to isolate the edge contour. An ellipse is fitted to the lens outline to obtain central reference point for transforming the pixel data into the analysis coordinate system. This allows for the fitting of a high order equation to obtain a mathematical description of the edge contour, which obeys constraints of continuity as well as zero to infinite surface slopes from apex to equator. Geometrical parameters of the lens were determined for the lens images captured at different accommodative states. Various curve fitting functions were developed to mathematically describe the anterior and posterior surfaces of the lens. Their differences were evaluated and their suitability for extracting optical performance of the lens was assessed. The robustness of these algorithms was tested by analyzing the same images repeated times.

  17. Corneal confocal microscopy and dry eye findings in contact lens discomfort patients.

    Science.gov (United States)

    Dogan, Aysun Sanal; Gurdal, Canan; Arslan, Nese

    2018-02-01

    To evaluate the corneal confocal microscopy and dry eye findings in patients with contact lens discomfort. The study included 3 groups of participants: Contact lens wearers using silicone hydrogel soft contact lenses who are symptomatic (CLD, n=15) or asymptomatic (ACL, n=11) and non-wearers as controls (n=14). Duration of contact lens wear, Ocular Surface Disease Index (OSDI) questionnaire responses, fluorescein tear break-uptime (FBUT), and corneal confocal microscopy findings were recorded. Mean age was 25.7±8.2 years and male/female ratio was 7/33. Demographic findings were similar regarding the groups. CLD patients had a longer lens use history than ACL (median 5 vs 2 years, pCLD group than ACL or controls (pCLD group, compared to controls and ACL (pCLD group compared to controls but similar to ACL (pCLD group than the ACL (p=0.014). Patients with CLD had been wearing contact lenses for longer than those without symptoms. OSDI and FBUT scores were worse in CLD patients. In contact lens discomfort patients, there were increased dendritiform cells, indicating intensified inflammatory status of the cornea. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  18. Lens Dk/t influences the clinical response in overnight orthokeratology.

    Science.gov (United States)

    Lum, Edward; Swarbrick, Helen A

    2011-04-01

    To investigate the influence of lens oxygen transmissibility (Dk/t) on the clinical response to overnight (ON) orthokeratology (OK) lens wear over 2 weeks. Eleven subjects (age, 20 to 39 years) were fitted with OK lenses (BE; Capricornia Contact Lens) in both eyes. Lenses in matched design/fitting but different materials (Boston EO and XO; nominal Dk/t: 26 and 46 ISO Fatt, respectively) were worn ON only in the two eyes over a 2-week period. Changes in logarithm of the minimum angle of resolution visual acuity, subjective refraction (spherical equivalent), corneal apical radius ro and asphericity Q (Medmont E300), and central stromal thickness (Holden-Payor optical pachometer) were measured. There were statistically significant differences in outcomes between the two lens materials (analysis of variance, p 0.05). An increase in lens Dk/t appears to increase the clinical effects of ON reverse-geometry lens wear over the medium term. This adds further support to the recommendation that high Dk materials should be used for ON OK not only to provide physiological advantages but also to optimize clinical outcomes.

  19. Vitamin C degradation products and pathways in the human lens.

    Science.gov (United States)

    Nemet, Ina; Monnier, Vincent M

    2011-10-28

    Vitamin C and its degradation products participate in chemical modifications of proteins in vivo through non-enzymatic glycation (Maillard reaction) and formation of different products called advanced glycation end products. Vitamin C levels are particularly high in selected tissues, such as lens, brain and adrenal gland, and its degradation products can inflict substantial protein damage via formation of advanced glycation end products. However, the pathways of in vivo vitamin C degradation are poorly understood. Here we have determined the levels of vitamin C oxidation and degradation products dehydroascorbic acid, 2,3-diketogulonic acid, 3-deoxythreosone, xylosone, and threosone in the human lens using o-phenylenediamine to trap both free and protein-bound adducts. In the protein-free fraction and water-soluble proteins (WSP), all five listed degradation products were identified. Dehydroascorbic acid, 2,3-diketogulonic acid, and 3-deoxythreosone were the major products in the protein-free fraction, whereas in the WSP, 3-deoxythreosone was the most abundant measured dicarbonyl. In addition, 3-deoxythreosone in WSP showed positive linear correlation with age (p degradation product bound to human lens proteins provides in vivo evidence for the non-oxidative pathway of dehydroascorbate degradation into erythrulose as a major pathway for vitamin C degradation in vivo.

  20. Early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: an economic evaluation based on data from the EAGLE trial

    Science.gov (United States)

    Javanbakht, Mehdi; Azuara-Blanco, Augusto; Burr, Jennifer M; Ramsay, Craig; Cooper, David; Cochran, Claire; Norrie, John; Scotland, Graham

    2017-01-01

    Objective To investigate the cost-effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma (PACG) compared to standard care. Design Cost-effectiveness analysis alongside a multicentre pragmatic two-arm randomised controlled trial. Patients were followed-up for 36 months, and data on health service usage and health state utility were collected and analysed within the trial time horizon. A Markov model was developed to extrapolate the results over a 5-year and 10-year time horizon. Setting 22 hospital eye services in the UK. Population Males and females aged 50 years or over with newly diagnosed PACG or primary angle closure (PAC). Interventions Lens extraction compared to standard care (ie, laser iridotomy followed by medical therapy and glaucoma surgery). Outcome measures Costs of primary and secondary healthcare usage (UK NHS perspective), quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER) for lens extraction versus standard care. Results The mean age of participants was 67.5 (8.42), 57.5% were women, 44.6% had both eyes eligible, 1.4% were of Asian ethnicity and 35.4% had PAC. The mean health service costs were higher in patients randomised to lens extraction: £2467 vs £1486. The mean adjusted QALYs were also higher with early lens extraction: 2.602 vs 2.533. The ICER for lens extraction versus standard care was £14 284 per QALY gained at three years. Modelling suggests that the ICER may drop to £7090 per QALY gained by 5 years and that lens extraction may be cost saving by 10 years. Our results are generally robust to changes in the key input parameters and assumptions. Conclusions We find that lens extraction has a 67–89% chance of being cost-effective at 3 years and that it may be cost saving by 10 years. Trial registration number ISRCTN44464607; Results. PMID:28087548

  1. 21 CFR 886.1395 - Diagnostic Hruby fundus lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic Hruby fundus lens. 886.1395 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1395 Diagnostic Hruby fundus lens. (a) Identification. A diagnostic Hruby fundus lens is a device that is a 55 diopter lens intended for use in the...

  2. 21 CFR 886.5844 - Prescription spectacle lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prescription spectacle lens. 886.5844 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5844 Prescription spectacle lens. (a) Identification. A prescription spectacle lens is a glass or plastic device that is a lens intended to be worn by...

  3. 21 CFR 886.1390 - Flexible diagnostic Fresnel lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flexible diagnostic Fresnel lens. 886.1390 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1390 Flexible diagnostic Fresnel lens. (a) Identification. A flexible diagnostic Fresnel lens is a device that is a very thin lens which has...

  4. UVA Light-excited Kynurenines Oxidize Ascorbate and Modify Lens Proteins through the Formation of Advanced Glycation End Products

    Science.gov (United States)

    Linetsky, Mikhail; Raghavan, Cibin T.; Johar, Kaid; Fan, Xingjun; Monnier, Vincent M.; Vasavada, Abhay R.; Nagaraj, Ram H.

    2014-01-01

    Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood. Kynurenines are tryptophan oxidation products produced from the indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway and are present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins. UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ASC, and such oxidation occurred even in the absence of oxygen. High levels of GSH inhibited but did not completely block ASC oxidation. Upon UVA irradiation, pigmented proteins from human cataractous lenses also oxidized ASC. When exposed to UVA light (320–400 nm, 100 milliwatts/cm2, 45 min to 2 h), young human lenses (20–36 years), which contain high levels of free kynurenines, lost a significant portion of their ASC content and accumulated AGEs. A similar formation of AGEs was observed in UVA-irradiated lenses from human IDO/human sodium-dependent vitamin C transporter-2 mice, which contain high levels of kynurenines and ASC. Our data suggest that kynurenine-mediated ASC oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans. PMID:24798334

  5. K sup + nucleus total cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Sawafta, R.

    1990-01-01

    The scattering of K{sup +} mesons from nuclei has attracted considerable interest in the last few years. The K{sup +} holds a very special position as the weakest of all strongly interaction probes. The average cross section is not larger than about 10 mb at lab momenta below 800 MeV/c, corresponding to a mean free path in the nucleus larger than 5 fm. Thus the K{sup +} is capable of probing the entire volume of the nucleus. Single scattering of the K{sup +} with a nucleon in the nucleus dominates the nuclear scattering, and only small and calculable higher order corrections are needed. The nucleon is a dynamical entity and its internal structure can, in principle, be altered by its surrounding nuclear environment. This work reports an experiment in which the K{sup +} is used to compare the nucleon in the nucleus with a free nucleon.

  6. The nucleus in Finland - The second report

    International Nuclear Information System (INIS)

    Aurela, Jorma; Korteniemi, Virpi; Halme-Tapanainen, Kristina

    1993-01-01

    The Finnish Nuclear Society (FNS) started the distribution of the Nucleus bulletin at the beginning of 1988. The volume of distribution has been extended since, including today nearly 1,000 persons. Both the English and the Finnish version of the bulletin is sent to various opinion leaders of society, i.e. the members of the parliament, ministries, the media, representatives of industry and other decision-makers of the energy field. After the five-year history of the Nucleus in Finland, it is time to look back and sum up the present status of the Nucleus. This report gives a short summary concerning the present distribution and its efficiency, the experiences gained and the influence of the bulletin in Finland. The first questionnaire was sent in November 1988, and the survey was repeated among the Finnish readers of the Nucleus in autumn 1992. The results of the latter survey are given in this report

  7. Microtubules move the nucleus to quiescence.

    Science.gov (United States)

    Laporte, Damien; Sagot, Isabelle

    2014-01-01

    The nucleus is a cellular compartment that hosts several macro-molecular machines displaying a highly complex spatial organization. This tight architectural orchestration determines not only DNA replication and repair but also regulates gene expression. In budding yeast microtubules play a key role in structuring the nucleus since they condition the Rabl arrangement in G1 and chromosome partitioning during mitosis through their attachment to centromeres via the kinetochore proteins. Recently, we have shown that upon quiescence entry, intranuclear microtubules emanating from the spindle pole body elongate to form a highly stable bundle that spans the entire nucleus. Here, we examine some molecular mechanisms that may underlie the formation of this structure. As the intranuclear microtubule bundle causes a profound re-organization of the yeast nucleus and is required for cell survival during quiescence, we discuss the possibility that the assembly of such a structure participates in quiescence establishment.

  8. Transport of glutathione into the nucleus.

    Science.gov (United States)

    Queval, Guillaume; Foyer, Christine

    2014-10-01

    The tripeptide thiol glutathione (GSH) is present in the nucleus of plant and animal cells. However, the functions of GSH in the nucleus remain poorly characterised. GSH appears to become sequestered in the nucleus at the early stages of the cell cycle. As part of our search for proteins that may be involved in GSH transport into the nucleus, we studied the functions of the nucleoporin called Alacrima Achalasia aDrenal Insufficiency Neurologic disorder (ALADIN). ALADIN is encoded by the Achalasia-Addisonianism-Alacrimia (AAAS) gene in mammalian cells. Defects in ALADIN promote adrenal disorders and lead to the triple A syndrome in humans. The ALADIN protein localizes to the nuclear envelope in Arabidopsis thaliana and interacts with other components of the nuclear pore complex (NPC). We characterised the functions of the ALADIN protein in an Arabidopsis thaliana T-DNA insertion knockout mutant, which shows slow growth compared to the wild type. Copyright © 2014. Published by Elsevier Inc.

  9. Nuclear physics: Unexpected doubly-magic nucleus

    International Nuclear Information System (INIS)

    Janssens, R.V.F.

    2009-01-01

    Nuclei with a 'magic' number of both protons and neutrons, dubbed doubly magic, are particularly stable. The oxygen isotope 24 O has been found to be one such nucleus - yet it lies just at the limit of stability

  10. Pion-nucleus cross sections approximation

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Polanski, A.; Sosnin, A.N.

    1990-01-01

    Analytical approximation of pion-nucleus elastic and inelastic interaction cross-section is suggested, with could be applied in the energy range exceeding several dozens of MeV for nuclei heavier than beryllium. 3 refs.; 4 tabs

  11. Kaon-nucleus reactions and hypernuclei

    International Nuclear Information System (INIS)

    Dover, C.B.

    1987-01-01

    Recent advances in hypernuclear physics and kaon-nucleus scattering are discussed, with emphasis on the spectroscopy of Λ single particle states in heavy systems, as revealed by the (π + ,K + ) reaction. 26 refs., 8 figs

  12. Non-invasive bleaching of the human lens by femtosecond laser photolysis

    DEFF Research Database (Denmark)

    Kessel, L.; Eskildsen, Lars; Poel, Mike van der

    2010-01-01

    . Reducing blindness from cataract requires solutions that can be applied outside operating theatres. Cataract is a protein conformational disease characterized by accumulation of light absorbing, fluorescent and scattering protein aggregates. The aim of the study was to investigate whether these compounds...... by a non-invasive procedure based on femtosecond laser photolysis. Cataract is a disease associated with old age. At the current technological stage, lens aging is delayed but with a treatment covering the entire lens volume complete optical rejuvenation is expected. Thus, femtosecond photolysis has...

  13. The correlation between the transverse polarization and transverse momentum of lambda produced in relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Ye Yunxiu; Zhou Xin; Ji Gang; Su Shufang; Zhu Guohuai

    1996-01-01

    The transverse polarization of lambda produced in relativistic nucleus-nucleus collisions is determined. The effect from the interaction between spin moment and magnetic field is corrected. The near zero transverse polarization and non-correlation between transverse polarization and transverse momentum are obtained and compared to ones obtained from the nucleus-nucleus interactions at lower energies. This comparison shows that the production mechanism of lambdas in the relativistic nucleus-nucleus collisions is different from one in the nucleus-nucleus reactions at lower energies

  14. Analysis of phakic before intraocular lens implantation for fundus examination

    Directory of Open Access Journals (Sweden)

    Juan Chen

    2014-10-01

    Full Text Available AIM:To investigate the findings of the eyes which were examined preoperatively by three mirror contact lens before the implantation of implantable collamer lens(ICL. To analysis the retinal pathological changes and to explore the clinical analysis of early diagnosis and treatment in retinopathy on fundus examination before operation. METHODS:The retrospective case series study included 127 eyes of 64 patients who underwent phakic intraocular lens implantation were received the fundus examination by three mirror from April 2011 to April 2012 in our hospital. The age, refractive diopter, the findings of Goldmann three mirror examination and the condition of retinal photocoagulation were analysed and concluded.RESULTS: A total of 34 eyes(26.8%out of all 127 eyes(64 caseswere found to have peripheral retinal pathological changes. Eight eyes(6.3%with retinal holes, 15 eyes(11.8%with retinal lattice degeneration, 5 eyes(3.9%with retina cream degeneration, 3 eyes(2.4%with retinal paving stone degeneration,2 eyes with vitreoretinal adhesion and traction,1 eye(0.8%with retinal hemorrhage. Twenty-five cases were given retinal photocoagulation and then received the ICL implantation after 3mo. The follow-up time was 1a. No retinal detachment happened.CONCLUSION:Phakic before intraocular lens implantation for fundus examination by three mirror is contributed to find the peripheral retinal pathological changes and abnormity. And make the appropriate treatment before operation for improving the security of operation, it can also give help to the postoperative follow-up of the fundus of these patients.

  15. The correction of electron lens aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, P.W., E-mail: peter.hawkes@cemes.fr

    2015-09-15

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. - Highlights: • Geometrical aberration correction. • Chromatic aberration correction. • 50 pm resolution. • High-resolution electron energy-loss spectroscopy. • Extensive bibliographies.

  16. The correction of electron lens aberrations

    International Nuclear Information System (INIS)

    Hawkes, P.W.

    2015-01-01

    The progress of electron lens aberration correction from about 1990 onwards is chronicled. Reasonably complete lists of publications on this and related topics are appended. A present for Max Haider and Ondrej Krivanek in the year of their 65th birthdays. By a happy coincidence, this review was completed in the year that both Max Haider and Ondrej Krivanek reached the age of 65. It is a pleasure to dedicate it to the two leading actors in the saga of aberration corrector design and construction. They would both wish to associate their colleagues with such a tribute but it is the names of Haider and Krivanek (not forgetting Joachim Zach) that will remain in the annals of electron optics, next to that of Harald Rose. I am proud to know that both regard me as a friend as well as a colleague. - Highlights: • Geometrical aberration correction. • Chromatic aberration correction. • 50 pm resolution. • High-resolution electron energy-loss spectroscopy. • Extensive bibliographies

  17. Polarization and alignment of nucleus fission fragments

    International Nuclear Information System (INIS)

    Barabanov, A.L.; Grechukhin, D.P.

    1987-01-01

    Correlation of fragment orientation with orientation axis of fissile nucleus and with n-vector f vector of fragment divergence is considered. Estimations of polarization and alignment of fission fragments of preliminarily oriented nuclei in correlation (with n-vector f recording) and integral (with n-vector f averaging) experiments were conducted. It is shown that high sensitivity of polarization and fragment alignment to the character of nucleus movement at the stage of descent from barrier to rupture point exists

  18. New aspects of the atomic nucleus

    International Nuclear Information System (INIS)

    Wilkinson, D.H.

    1987-01-01

    We are at last just beginning to identify convincing evidence for what we have long believed, namely that the nucleus is more than the sum of its neutron-proton parts taken pairwise because, for example, a cluster of three nucleons interacts differently from the sum of the interactions of its three pairs; there is an important collectivism in the life of a nucleus even before we ask what its nucleons are doing. (orig./WL)

  19. Testing string dynamics in lepton nucleus reactions

    International Nuclear Information System (INIS)

    Gyulassy, M.; Pluemer, M.

    1989-10-01

    The sensitivity of nuclear attenuation of 10-100 GeV lepton nucleus (ell A) reactions to space-time aspects of hadronization is investigated within the context of the Lund string model. We consider two mechanisms for attenuation in a nucleus: final state cascading and string flip excitations. Implications for the evolution of the energy density in nuclear collisions are discussed. 16 refs., 10 figs

  20. Numerical Simulation of the Kinetic Critical Nucleus

    OpenAIRE

    Sanada, Masaaki; Nishioka, Kazumi; Okada, Masahumi; Maksimov, Igor, L.

    1997-01-01

    Our main interest is to see whether the number density indicates a peak at the kinetically stable critical nucleus due to its kinetical stability. We have numerically calculated the time evolution of the number densities of clusters in the case of water vapor nucleation. We employ the condition in which the difference between the size of the thermodynamic crtitical nucleus and that of the kinetic one is appreciable. The results show that the peak does not appear in the number densities of clu...

  1. Measurement of Crystalline Lens Volume During Accommodation in a Lens Stretcher.

    Science.gov (United States)

    Marussich, Lauren; Manns, Fabrice; Nankivil, Derek; Maceo Heilman, Bianca; Yao, Yue; Arrieta-Quintero, Esdras; Ho, Arthur; Augusteyn, Robert; Parel, Jean-Marie

    2015-07-01

    To determine if the lens volume changes during accommodation. The study used data acquired on 36 cynomolgus monkey lenses that were stretched in a stepwise fashion to simulate disaccommodation. At each step, stretching force and dioptric power were measured and a cross-sectional image of the lens was acquired using an optical coherence tomography system. Images were corrected for refractive distortions and lens volume was calculated assuming rotational symmetry. The average change in lens volume was calculated and the relation between volume change and power change, and between volume change and stretching force, were quantified. Linear regressions of volume-power and volume-force plots were calculated. The mean (± SD) volume in the unstretched (accommodated) state was 97 ± 8 mm3. On average, there was a small but statistically significant (P = 0.002) increase in measured lens volume with stretching. The mean change in lens volume was +0.8 ± 1.3 mm3. The mean volume-power and volume-load slopes were -0.018 ± 0.058 mm3/D and +0.16 ± 0.40 mm3/g. Lens volume remains effectively constant during accommodation, with changes that are less than 1% on average. This result supports a hypothesis that the change in lens shape with accommodation is accompanied by a redistribution of tissue within the capsular bag without significant compression of the lens contents or fluid exchange through the capsule.

  2. AutoLens: Automated Modeling of a Strong Lens's Light, Mass and Source

    Science.gov (United States)

    Nightingale, J. W.; Dye, S.; Massey, Richard J.

    2018-05-01

    This work presents AutoLens, the first entirely automated modeling suite for the analysis of galaxy-scale strong gravitational lenses. AutoLens simultaneously models the lens galaxy's light and mass whilst reconstructing the extended source galaxy on an adaptive pixel-grid. The method's approach to source-plane discretization is amorphous, adapting its clustering and regularization to the intrinsic properties of the lensed source. The lens's light is fitted using a superposition of Sersic functions, allowing AutoLens to cleanly deblend its light from the source. Single component mass models representing the lens's total mass density profile are demonstrated, which in conjunction with light modeling can detect central images using a centrally cored profile. Decomposed mass modeling is also shown, which can fully decouple a lens's light and dark matter and determine whether the two component are geometrically aligned. The complexity of the light and mass models are automatically chosen via Bayesian model comparison. These steps form AutoLens's automated analysis pipeline, such that all results in this work are generated without any user-intervention. This is rigorously tested on a large suite of simulated images, assessing its performance on a broad range of lens profiles, source morphologies and lensing geometries. The method's performance is excellent, with accurate light, mass and source profiles inferred for data sets representative of both existing Hubble imaging and future Euclid wide-field observations.

  3. Placement of a crystalline lens and intraocular lens: Retinal image quality.

    Science.gov (United States)

    Siedlecki, Damian; Nowak, Jerzy; Zajac, Marek

    2006-01-01

    The influence of changes of both crystalline lens and intraocular lens (IOL) misalignment on the retinal image quality was investigated. The optical model of the eye used in investigations was the Liou-Brennan model, which is commonly considered as one of the most anatomically accurate. The original crystalline lens from this model was replaced with an IOL, made of rigid polymethylmethacrylate, in a way that recommend obligatory procedures. The modifications that were made both for crystalline lens and IOL were the longitudinal, the transversal, and the angular displacement.

  4. Development of Fresnel lens for improvement of rear visibility; Shikai kojo Fresnel lens no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, K; Sanada, C; Tsukino, M [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    Fresnel lenses have been widely used to increase the visual field around vehicles for drivers. However, internal reflection in these lenses has been an obstacle in producing dear images. This internal glow is generated by incident light from an unexpected direction reflecting on the non-lens surface or radiating from the non-lens surface of the Fresnel lens. The cause of internal glow has been made dear combining louver film with the lens. The newly developed technology removes obstacles in producing dear images by reducing internal glow. 7 figs.

  5. Disinfection capacity of PuriLens contact lens cleaning unit against Acanthamoeba.

    Science.gov (United States)

    Hwang, Thomas S; Hyon, Joon Young; Song, Jae Kyung; Reviglio, Victor E; Spahr, Harry T; O'Brien, Terrence P

    2004-01-01

    The PuriLens contact lens system is indicated for cleaning and disinfection of soft (hydrophilic) contact lenses by means of subsonic agitation to remove lens deposits and microorganisms, and ultraviolet irradiation of the storage solution for disinfection. The capacity of the PuriLens system to disinfect storage solutions contaminated with known concentrations of Staphylococcus aureus, Pseudomonas aeruginosa, and Acanthamoeba species was evaluated. An in vitro assessment of the antibacterial and antiparasitic efficacy of the PuriLens system was performed. Separated batches of the storage solution for the cleansing system were contaminated with stock strains of S. aureus and P. aeruginosa. A comparison of the microbiologic content was made between the solution before and after the cycle. The PuriLens system effectively eradicated S. aureus and P. aeruginosa organisms after a 15-minute cycle. However, viable cysts of acanthamoeba were recovered in the solution after the 15-minute cycle. The PuriLens system is highly efficient in protecting against contamination with common bacterial ocular pathogens. Acanthamoeba cysts, however, can survive in the solution or contact lens bath undergoing integrated subsonic debridement and indirect ultraviolet light disinfection. Use of chemical disinfecting solutions that contain agents such as chlorhexidine or other cationic antiseptics may be advisable in conjunction with use of the PuriLens device, especially in high-risk settings.

  6. Night Vision Goggles Objectives Lens Focusing Methodology

    National Research Council Canada - National Science Library

    Pinkus, Alan; Task, H. L

    2000-01-01

    ...: interpupillary distance, tilt, eye relief, height, eyepiece and objective lens focus. Currently, aircrew use a Hoffman 20/20 test unit to pre-focus their NVG objective lenses at optical infinity before boarding their aircraft...

  7. Characteristics of soft X-ray lens

    International Nuclear Information System (INIS)

    Qin Yi

    2007-12-01

    A soft X-lens was devised with waveguide X-ray optics of total external reflection (TER). The lens consists of a stack of 1 387 TER waveguides with inner diameter of 0.45 mm and outer diameter of 0.60 mm. With the help of plasma sources of soft X-ray radiation, high density of pure soft X-ray radiation (without plasma expansion fragments) with broad-band spectral range can be obtained at the focus of the lens. As laser-plasma is considered, the radiation density of 1.3 x 10 5 W/cm 2 is obtained, the transmission coefficient is 18.6%, the ratio of the density at the focus with and without the lens is 1000 and the radiation capture is 28.9 degree. The density of 0.5 TW/cm 2 can be obtained as far as Qiang-Guang I facility is considered. (authors)

  8. Gravitational lens effect and pregalactic halo objects

    International Nuclear Information System (INIS)

    Bontz, R.J.

    1979-01-01

    The changes in flux, position, and size of a distant extended (galaxy, etc.) source that result from the gravitational lens action of a massive opaque object are discussed. The flux increase is described by a single function of two parameters. One of these parameters characterizes the strength of the gravitational lens, the other describes the alignment of source and lens object. This function also describes the relative intensity of the images formed by lens. ( A similar formalism is discussed by Bourassa et al. for a point source). The formalism is applied to the problem of the galactic halo. It appears that a massive (10 1 2 M/sub sun/) spherical halo surrounding the visible part of the galaxy is consistent with the observable properties of extragalactic sources

  9. Discovery of two new gravitation lens systems

    International Nuclear Information System (INIS)

    Guertler, J.

    1988-01-01

    The discovery of new quasar and radio galaxy double images produced by the gravitation lens effect is reported. The light deflecting galaxies acting as gravitational lenses could be made visible by means of image processing procedures

  10. A Plasma Lens for Magnetron Sputtering

    International Nuclear Information System (INIS)

    Anders, Andre; Brown, Jeff

    2010-01-01

    A plasma lens, consisting of a solenoid and potential-defining ring electrodes, has been placed between a magnetron and substrates to be coated. Photography reveals qualitative information on excitation, ionization, and the transport of plasma to the substrate.

  11. The discovery of a gravitational lens

    International Nuclear Information System (INIS)

    Chaffee, F.H. Jr.

    1981-01-01

    A recently discovered pair of quasars turns out to be not a pair at all but two images of a single quasar formed by a gravitational lens: an elliptical galaxy halfway between the quasar and our own galaxy. (orig.) [de

  12. EDEL: ENEA dosemeter for eye lens

    International Nuclear Information System (INIS)

    Ferrari, Paolo; Mariotti, Francesca; Campani, Lorenzo

    2016-01-01

    Since the publication of International Commission on Radiological Protection statement in 2011 on tissue reaction, eye lens radiation protection played an important role in exposed personnel dosimetry. For this reason, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) Individual Monitoring Service decided to study a prototype to fulfil specific requests (e.g. for survey in interventional department and intercomparisons). On the basis of such preliminary investigation, a new eye lens dosemeter was developed. The new dosemeter, named EDEL (ENEA Dosemeter for Eye Lens), was characterised in terms of H p (3), the operational quantity related to eye lens monitoring. The investigation was performed experimentally and optimised using the Monte Carlo MCNP6 code. The new prototype was thought to fulfil two main requests: the reliability of the dosimetric data and the portability of the dosemeter itself. The new dosemeter will soon be supplied to the collaborating hospitals for workplace test measurements. (authors)

  13. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  14. Improved Cloud Condensation Nucleus Spectrometer

    Science.gov (United States)

    Leu, Ming-Taun

    2010-01-01

    An improved thermal-gradient cloud condensation nucleus spectrometer (CCNS) has been designed to provide several enhancements over prior thermal- gradient counters, including fast response and high-sensitivity detection covering a wide range of supersaturations. CCNSs are used in laboratory research on the relationships among aerosols, supersaturation of air, and the formation of clouds. The operational characteristics of prior counters are such that it takes long times to determine aerosol critical supersaturations. Hence, there is a need for a CCNS capable of rapid scanning through a wide range of supersaturations. The present improved CCNS satisfies this need. The improved thermal-gradient CCNS (see Figure 1) incorporates the following notable features: a) The main chamber is bounded on the top and bottom by parallel thick copper plates, which are joined by a thermally conductive vertical wall on one side and a thermally nonconductive wall on the opposite side. b) To establish a temperature gradient needed to establish a supersaturation gradient, water at two different regulated temperatures is pumped through tubes along the edges of the copper plates at the thermally-nonconductive-wall side. Figure 2 presents an example of temperature and supersaturation gradients for one combination of regulated temperatures at the thermally-nonconductive-wall edges of the copper plates. c) To enable measurement of the temperature gradient, ten thermocouples are cemented to the external surfaces of the copper plates (five on the top plate and five on the bottom plate), spaced at equal intervals along the width axis of the main chamber near the outlet end. d) Pieces of filter paper or cotton felt are cemented onto the interior surfaces of the copper plates and, prior to each experimental run, are saturated with water to establish a supersaturation field inside the main chamber. e) A flow of monodisperse aerosol and a dilution flow of humid air are introduced into the main

  15. Role of Aquaporin 0 in lens biomechanics.

    Science.gov (United States)

    Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

  16. Evolution and the Calcite Eye Lens

    OpenAIRE

    Williams, Vernon L.

    2013-01-01

    Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

  17. Lens Design Using Group Indices of Refraction

    Science.gov (United States)

    Vaughan, A. H.

    1995-01-01

    An approach to lens design is described in which the ratio of the group velocity to the speed of light (the group index) in glass is used, in conjunction with the more familiar phase index of refraction, to control certain chromatic properties of a system of thin lenses in contact. The first-order design of thin-lens systems is illustrated by examples incorporating the methods described.

  18. Orbiting objective lens telescope system and method

    International Nuclear Information System (INIS)

    Crooks, J.W. Jr.

    1984-01-01

    A large objective lens is placed in a highly eccentric orbit about the earth. The orbit and orientation of the lens are carefully chosen so that it focuses light or other radiation from a preselected astronomical object into an image which slowly moves across the surface of the earth. A row of optical sensing units is located on the surface of the earth so that the image focused by the orbiting objective lens will travel substantially perpendicularly across the row during an observation. Output data generated from the sensing units may be multiplexed and fed to a real time processor which produces display signals. Each of the sensing units provides one scan line of the image being observed. The display signals are fed to a suitable display device which produces a picture of the preselected astronomical object. The objective lens may comprise a large flexible Fresnel zone plate or a flexible convex lens carried by a bicycle wheel-type supporting structure. The lens and supporting structure may be unfolded from compact cargo configurations and rotated after being placed into orbit

  19. Photon nanojet lens: design, fabrication and characterization

    International Nuclear Information System (INIS)

    Xu, Chen; Zhang, Sichao; Shao, Jinhai; Lu, Bing-Rui; Chen, Yifang; Mehfuz, Reyad; Drakeley, Stacey; Huang, Fumin

    2016-01-01

    In this paper, a novel nanolens with super resolution, based on the photon nanojet effect through dielectric nanostructures in visible wavelengths, is proposed. The nanolens is made from plastic SU-8, consisting of parallel semi-cylinders in an array. This paper focuses on the lens designed by numerical simulation with the finite-difference time domain method and nanofabrication of the lens by grayscale electron beam lithography combined with a casting/bonding/lift-off transfer process. Monte Carlo simulation for injected charge distribution and development modeling was applied to define the resultant 3D profile in PMMA as the template for the lens shape. After the casting/bonding/lift-off process, the fabricated nanolens in SU-8 has the desired lens shape, very close to that of PMMA, indicating that the pattern transfer process developed in this work can be reliably applied not only for the fabrication of the lens but also for other 3D nanopatterns in general. The light distribution through the lens near its surface was initially characterized by a scanning near-field optical microscope, showing a well defined focusing image of designed grating lines. Such focusing function supports the great prospects of developing a novel nanolithography based on the photon nanojet effect. (paper)

  20. Contact lens rehabilitation following repaired corneal perforations

    Science.gov (United States)

    Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

    2006-01-01

    Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

  1. Conservation through the economics lens.

    Science.gov (United States)

    Farley, Joshua

    2010-01-01

    Although conservation is an inherently transdisciplinary issue, there is much to be gained from examining the problem through an economics lens. Three benefits of such an approach are laid out in this paper. First, many of the drivers of environmental degradation are economic in origin, and the better we understand them, the better we can conserve ecosystems by reducing degradation. Second, economics offers us a when-to-stop rule, which is equivalent to a when-to-conserve rule. All economic production is based on the transformation of raw materials provided by nature. As the economic system grows in physical size, it necessarily displaces and degrades ecosystems. The marginal benefits of economic growth are diminishing, and the marginal costs of ecological degradation are increasing. Conceptually, we should stop economic growth and focus on conservation when the two are equal. Third, economics can help us understand how to efficiently and justly allocate resources toward conservation, and this paper lays out some basic principles for doing so. Unfortunately, the field of economics is dominated by neoclassical economics, which builds an analytical framework based on questionable assumptions and takes an excessively disciplinary and formalistic approach. Conservation is a complex problem, and analysis from individual disciplinary lenses can make important contributions to conservation only when the resulting insights are synthesized into a coherent vision of the whole. Fortunately, there are a number of emerging transdisciplines, such as ecological economics and environmental management, that are dedicated to this task.

  2. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    International Nuclear Information System (INIS)

    Konchakovski, Volodymyr P.

    2009-01-01

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the optimal

  3. Fluctuations and correlations in nucleus-nucleus collisions within transport approaches

    Energy Technology Data Exchange (ETDEWEB)

    Konchakovski, Volodymyr P.

    2009-10-01

    The current thesis is devoted to a systematic study of fluctuations and correlations in heavy-ion collisions, which might be considered as probes for the phase transition and the critical point in the phase diagram, within the Hadron-String- Dynamics (HSD) microscopic transport approach. This is a powerful tool to study nucleus-nucleus collisions and allows to completely simulate experimental collisions on an event-by-event basis. Thus, the transport model has been used to study fluctuations and correlations including the influence of experimental acceptance as well as centrality, system size and collision energy. The comparison to experimental data can separate the effects induced by a phase transition since there is no phase transition in the HSD version used here. Firstly the centrality dependence of multiplicity fluctuations has been studied. Different centrality selections have been performed in the analysis in correspondence to the experimental situation. For the fixed target experiment NA49 events with fixed numbers of the projectile participants have been studied while in the collider experiment PHENIX centrality classes of events have been defined by the multiplicity in certain phase space region. A decrease of participant number fluctuations (and thus volume fluctuations) in more central collisions for both experiments has been obtained. Another area of this work addresses to transport model calculations of multiplicity fluctuations in nucleus-nucleus collisions as a function of colliding energy and system size. This study is in full correspondence to the experimental program of the NA61 Collaboration at the SPS. Central C+C, S+S, In+In, and Pb+Pb nuclear collisions at Elab = 10, 20, 30, 40, 80, 158 AGeV have been investigated. The expected enhanced fluctuations - attributed to the critical point and phase transition - can be observed experimentally on top of a monotonic and smooth 'hadronic background'. These findings should be helpful for the

  4. Effect of gamma irradiation on in vitro bovine lens proteins

    International Nuclear Information System (INIS)

    Bernardes, D.M.L.; Mastro, N.L. del.

    1988-07-01

    The radiosensitivity of the ocular lens manifested by cataract formation has been of considerable interest in the study on the biological efects of radiations. Cataract can ben produced by different causes and also for the normal process of ageing. The aim of this work was to develop an in vitro system similar to in vivo cataract formation. It was used an aqueous solution of bovine lenses. The lenses after surgical removal mechanical and ultrasonic disrupted. The suspension was centrifuged and the supernatant was dialyzed and irradiated with different doses of 60 Co radiation. The opacification extent was measured in an spectrophotometer. (author) [pt

  5. Sharing of secondary electrons by in-lens and out-lens detector in low-voltage scanning electron microscope equipped with immersion lens.

    Science.gov (United States)

    Kumagai, Kazuhiro; Sekiguchi, Takashi

    2009-03-01

    To understand secondary electron (SE) image formation with in-lens and out-lens detector in low-voltage scanning electron microscopy (LV-SEM), we have evaluated SE signals of an in-lens and an out-lens detector in LV-SEM. From the energy distribution spectra of SEs with various boosting voltages of the immersion lens system, we revealed that the electrostatic field of the immersion lens mainly collects electrons with energy lower than 40eV, acting as a low-pass filter. This effect is also observed as a contrast change in LV-SEM images taken by in-lens and out-lens detectors.

  6. Study of the peculiarities of multiparticle production via event-by-event analysis in asymmetric nucleus-nucleus interactions

    Science.gov (United States)

    Fedosimova, Anastasiya; Gaitinov, Adigam; Grushevskaya, Ekaterina; Lebedev, Igor

    2017-06-01

    In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC), short-range multiparticle correlations (SC) and mixed type (MT) in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.

  7. Study of the peculiarities of multiparticle production via event-by-event analysis in asymmetric nucleus-nucleus interactions

    Directory of Open Access Journals (Sweden)

    Fedosimova Anastasiya

    2017-01-01

    Full Text Available In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC, short-range multiparticle correlations (SC and mixed type (MT in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.

  8. Analysis of causes of intraocular lens explantations in the material of Department of Ophthalmology, Medical University of Lodz.

    Science.gov (United States)

    Wilczyński, Michał; Wilczyńska, Olena; Omulecki, Wojciech

    2009-01-01

    Implantation of intraocular lenses (IOLS) has become a standard practice in cataract surgery, however, similar to any other type of surgery, using IOLs is not complication-free and sometimes explantation of intraocular lenses may be necessary. This study was to gather data and analyze causes of intraocular lens explantations, performed in the Department of Ophthalmology, Medical University of Łódź. The data were gathered from medical documentation of all patients who underwent intraocular lens removal from January 2003 to July 2006. The examined group consisted of 16 patients (16 eyes): 9 women (fraction 0.56), and 7 men (fraction 0.44), at the age from 21 to 82 years (mean age 62.4 years, SD +/- 15.5). In all patients IOL explantation was performed under local, peribulbar anaesthesia. Two groups of patients were distinguished: patients who had an anterior chamber lens explanted (3 patients, fraction 0.19) and patients who underwent posterior chamber lens explantation (13 patients, fraction 0.81). Causes of AC IOL explantations were: vaulting of the IOL (1 eye, fraction 0.06), luxation of the IOL to the vitreous cavity (1 eye, fraction 0.06), and painful eyeball after anterior chamber lens implantation (1 eye, fraction 0.06). Causes of PC IOL explantations were: subluxation of the IOL (6 eyes, fraction 0.38), luxation of the lens to the vitreous cavity (3 eyes, fraction 0.19), luxation of the lens to the anterior chamber (1 eye, fraction 0.06), endophthalmitis (2 eyes, fraction 0.13) and incorrect lens power (1 eye, fraction 0.06). In the majority of eyes (n = 13, fraction 0.81) the removed implant was replaced by another intraocular lens, but 3 eyes (fraction 0.19) were left aphakic. We did not observe serious intra- or early postoperative complications which might influence the final result of the operation.

  9. Quark matter formation in high energy nucleus-nucleus collisions - predictions and observations

    International Nuclear Information System (INIS)

    Otterlund, I.

    1983-01-01

    In this talk I give a short summary of the recent discussion around predictions and possible observations of quark-gluon plasma and fireballs in ultrarelativistic nucleus-nucleus collisions. In particular this talk is focused on heavy ion reactions at 200 A GeV. (orig./HSI)

  10. Effective number of inelastically interacting nucleons in rare nucleus-nucleus production processes

    International Nuclear Information System (INIS)

    Korotkikh, V.L.; Lokhtin, I.P.

    1992-01-01

    A model of nucleus-nucleus interaction using one inelastic NN-interaction is suggested for the exclusive production processes with small cross-section. A-dependence nuclear coherent and incoherent production cross-section are predicted. 20 refs.; 4 figs

  11. High density QCD and nucleus-nucleus scattering deeply in the saturation region

    International Nuclear Information System (INIS)

    Kormilitzin, Andrey; Levin, Eugene; Miller, Jeremy S.

    2011-01-01

    In this paper we solve the equations that describe nucleus-nucleus scattering, in high density QCD, in the framework of the BFKL Pomeron Calculus. We found that (i) the contribution of short distances to the opacity for nucleus-nucleus scattering dies at high energies, (ii) the opacity tends to unity at high energy, and (iii) the main contribution that survives comes from soft (long distance) processes for large values of the impact parameter. The corrections to the opacity Ω(Y,b)=1 were calculated and it turns out that they have a completely different form, namely (1-Ω→exp(-Const√(Y))) than the opacity that stems from the Balitsky-Kovchegov equation, which is (1-Ω→exp(-ConstY 2 )). We reproduce the formula for the nucleus-nucleus cross section that is commonly used in the description of nucleus-nucleus scattering, and there is no reason why it should be correct in the Glauber-Gribov approach.

  12. Production of strange and multistrange hadrons in nucleus-nucleus collisions at the SPS

    Czech Academy of Sciences Publication Activity Database

    Antinori, F.; Bakke, H.; Beusch, W.; Staroba, Pavel; Závada, Petr

    1999-01-01

    Roč. 661, - (1999), 130c-139c ISSN 0375-9474 Institutional research plan: CEZ:AV0Z1010920 Keywords : production * nucleus-nucleus collisions * hadrons * strangeness * model predictions Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.088, year: 1999

  13. The mechanism of nuclear energy release in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Strugalski, Z.; Strugalska-Gola, E.

    1998-01-01

    The mechanism of intranuclear energy release in reactions induced by nucleus-nucleus collisions at energies higher than ∼ 0.5 GeV/nucl. is presented - as prompted experimentally. The intranuclear energy release goes through local damages of the colliding nuclei

  14. Study of η-nucleus interaction through the formation of η-nucleus ...

    Indian Academy of Sciences (India)

    Answer to this question will deeply enrich our understanding of -nucleus interaction which is not so well-understood. We review the experimental efforts for the search of -mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search of -nucleus bound state using ...

  15. Effect of infusion bottle height on lens power after lens refilling with and without a plug

    NARCIS (Netherlands)

    Koopmans, SA; Terwee, T; Haitjema, HJ; Kooijman, AC; Barkhof, J

    2003-01-01

    Purpose: To evaluate the influence of intraoperative infusion bottle height on the power of refilled pig lenses. Setting: Research Laboratory, Pharmacia Intraocular Lens Manufacturing Plant, Groningen, The Netherlands. Methods: This study comprised 2 groups of pig eyes. In 1 group, the lens was

  16. Structural dynamics of the cell nucleus

    Science.gov (United States)

    Wiegert, Simon; Bading, Hilmar

    2011-01-01

    Neuronal morphology plays an essential role in signal processing in the brain. Individual neurons can undergo use-dependent changes in their shape and connectivity, which affects how intracellular processes are regulated and how signals are transferred from one cell to another in a neuronal network. Calcium is one of the most important intracellular second messengers regulating cellular morphologies and functions. In neurons, intracellular calcium levels are controlled by ion channels in the plasma membrane such as NMDA receptors (NMDARs), voltage-gated calcium channels (VGCCs) and certain α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) as well as by calcium exchange pathways between the cytosol and internal calcium stores including the endoplasmic reticulum and mitochondria. Synaptic activity and the subsequent opening of ligand and/or voltage-gated calcium channels can initiate cytosolic calcium transients which propagate towards the cell soma and enter the nucleus via its nuclear pore complexes (NPCs) embedded in the nuclear envelope. We recently described the discovery that in hippocampal neurons the morphology of the nucleus affects the calcium dynamics within the nucleus. Here we propose that nuclear infoldings determine whether a nucleus functions as an integrator or detector of oscillating calcium signals. We outline possible ties between nuclear mophology and transcriptional activity and discuss the importance of extending the approach to whole cell calcium signal modeling in order to understand synapse-to-nucleus communication in healthy and dysfunctional neurons. PMID:21738832

  17. The nuclear response and the imaginary potential for nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Phatak, S.C.; Sinha, B.

    1983-01-01

    The Fermi-gas model is used in this paper to study the nucleus-nucleus collision. The field produced by one of the nuclei is considered to act on nucleons in the other nucleus, which is treated as a Fermi gas of radius R. The imaginary part of the (non-local) nucleus-nucleus potential is then computed by evaluating the energy-conserving second-order term in which the intermediate states are particle-hole excitations produced in the Fermi gas. The equivalent local potential, obtained by using the Perey-Saxon method, is compared with phenomenological imaginary potentials. Later it is shown that, in the limit of small range of non-locality, the imaginary potential can be related to the nuclear response function. With this, one can write the nuclear friction coefficient that is used in phenomenological analyses of heavy-ion collisions in terms of the imaginary potential. (orig.)

  18. Nuclear magnetic resonance studies of lens transparency

    International Nuclear Information System (INIS)

    Beaulieu, C.F.

    1989-01-01

    Transparency of normal lens cytoplasm and loss of transparency in cataract were studied by nuclear magnetic resonance (NMR) methods. Phosphorus ( 31 P) NMR spectroscopy was used to measure the 31 P constituents and pH of calf lens cortical and nuclear homogenates and intact lenses as a function of time after lens enucleation and in opacification produced by calcium. Transparency was measured with laser spectroscopy. Despite complete loss of adenosine triphosphate (ATP) within 18 hrs of enucleation, the homogenates and lenses remained 100% transparent. Additions of calcium to ATP-depleted cortical homogenates produced opacification as well as concentration-dependent changes in inorganic phosphate, sugar phosphates, glycerol phosphorylcholine and pH. 1 H relaxation measurements of lens water at 200 MHz proton Larmor frequency studied temperature-dependent phase separation of lens nuclear homogenates. Preliminary measurements of T 1 and T 2 with non-equilibrium temperature changes showed a change in the slope of the temperature dependence of T 1 and T 2 at the phase separation temperature. Subsequent studies with equilibrium temperature changes showed no effect of phase separation on T 1 or T 2 , consistent with the phase separation being a low-energy process. 1 H nuclear magnetic relaxation dispersion (NMRD) studies (measurements of the magnetic field dependence of the water proton 1/T 1 relaxation rates) were performed on (1) calf lens nuclear and cortical homogenates (2) chicken lens homogenates, (3) native and heat-denatured egg white and (4) pure proteins including bovine γ-II crystallin bovine serum albumin (BSA) and myoglobin. The NMRD profiles of all samples exhibited decreases in 1/T 1 with increasing magnetic field

  19. Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

    International Nuclear Information System (INIS)

    Konvalina, I.; Muellerova, I.

    2011-01-01

    The cathode lens is an electron optical element in an emission electron microscope accelerating electrons from the sample, which serves as a source for a beam of electrons. Special application consists in using the cathode lens first for retardation of an illuminating electron beam and then for acceleration of reflected as well as secondary electrons, made in the directly imaging low energy electron microscope or in its scanning version discussed here. In order to form a real image, the cathode lens has to be combined with a focusing magnetic lens or a focusing immersion-magnetic lens, as used for objective lenses of some commercial scanning electron microscopes. These two alternatives are compared with regards to their optical properties, in particular with respect to predicted aberration coefficients and the spot size, as well as the optimum angular aperture of the primary beam. The important role of the final aperture size on the image resolution is also presented.

  20. Optical integration of Pancharatnam-Berry phase lens and dynamical phase lens

    International Nuclear Information System (INIS)

    Ke, Yougang; Liu, Yachao; Zhou, Junxiao; Liu, Yuanyuan; Luo, Hailu; Wen, Shuangchun

    2016-01-01

    In the optical system, most elements such as lens, prism, and optical fiber are made of silica glass. Therefore, integrating Pancharatnam-Berry phase elements into silica glass has potential applications in the optical system. In this paper, we take a lens, for example, which integrates a Pancharatnam-Berry phase lens into a conventional plano-convex lens. The spin states and positions of focal points can be modulated by controlling the polarization states of the incident beam. The proposed lens has a high transmission efficiency, and thereby acts as a simple and powerful tool to manipulate spin photons. Furthermore, the method can be conveniently extended to the optical fiber and laser cavity, and may provide a route to the design of the spin-photonic devices.

  1. Cannabis use is quantitatively associated with nucleus accumbens and amygdala abnormalities in young adult recreational users.

    Science.gov (United States)

    Gilman, Jodi M; Kuster, John K; Lee, Sang; Lee, Myung Joo; Kim, Byoung Woo; Makris, Nikos; van der Kouwe, Andre; Blood, Anne J; Breiter, Hans C

    2014-04-16

    Marijuana is the most commonly used illicit drug in the United States, but little is known about its effects on the human brain, particularly on reward/aversion regions implicated in addiction, such as the nucleus accumbens and amygdala. Animal studies show structural changes in brain regions such as the nucleus accumbens after exposure to Δ9-tetrahydrocannabinol, but less is known about cannabis use and brain morphometry in these regions in humans. We collected high-resolution MRI scans on young adult recreational marijuana users and nonusing controls and conducted three independent analyses of morphometry in these structures: (1) gray matter density using voxel-based morphometry, (2) volume (total brain and regional volumes), and (3) shape (surface morphometry). Gray matter density analyses revealed greater gray matter density in marijuana users than in control participants in the left nucleus accumbens extending to subcallosal cortex, hypothalamus, sublenticular extended amygdala, and left amygdala, even after controlling for age, sex, alcohol use, and cigarette smoking. Trend-level effects were observed for a volume increase in the left nucleus accumbens only. Significant shape differences were detected in the left nucleus accumbens and right amygdala. The left nucleus accumbens showed salient exposure-dependent alterations across all three measures and an altered multimodal relationship across measures in the marijuana group. These data suggest that marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures and is consistent with animal studies of changes in dendritic arborization.

  2. Indications for the onset of deconfinement in nucleus nucleus collisions

    CERN Document Server

    Flierl, D.; Anticic, T.; Baatar, B.; Barna, D.; Bartke, J.; Betev, L.; Bialkowska, H.; Billmeier, A.; Blume, C.; Boimska, B.; Botje, M.; Bracinik, J.; Bramm, R.; Brun, R.; Buncic, P.; Cerny, V.; Christakoglou, P.; Chvala, O.; Cramer, J.G.; Csato, P.; Darmenov, N.; Dimitrov, A.; Dinkelaker, P.; Eckardt, V.; Farantatos, G.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Gal, J.; Gazdzicki, M.; Georgopoulos, G.; Gladysz, E.; Grebieszkow, K.; Hegyi, S.; Hohne, C.; Kadija, K.; Karev, A.; Kliemant, M.; Kniege, S.; Kolesnikov, V.I.; Kollegger, T.; Kornas, E.; Korus, R.; Kowalski, M.; Kraus, I.; Kreps, M.; van Leeuwen, M.; Levai, P.; Litov, L.; Lungwitz, B.; Makariev, M.; Malakhov, A.I.; Markert, C.; Mateev, M.; Mayes, B.W.; Melkumov, G.L.; Meurer, C.; Mischke, A.; Mitrovski, M.; Molnar, J.; Mrowczynski, S.; Palla, G.; Panagiotou, A.D.; Panayotov, D.; Petridis, A.; Pikna, M.; Pinsky, Lawrence S.; Puhlhofer, F.; Reid, J.G.; Renfordt, R.; Richard, A.; Roland, C.; Roland, G.; Rybczynski, M.; Rybicki, A.; Sandoval, A.; Sann, H.; Schmitz, N.; Seyboth, P.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Stefanek, G.; Stock, R.; Strobele, H.; Susa, T.; Szentpetery, I.; Sziklai, J.; Trainor, T.A.; Trubnikov, V.; Varga, D.; Vassiliou, M.; Veres, G.I.; Vesztergombi, G.; Vranic, D.; Wetzler, A.; Wlodarczyk, Z.; Yoo, I.K.; Zaranek, J.; Zimanyi, J.; Alt, C.; Anticic, T.; Baatar, B.; Barna, D.; Bartke, J.; Betev, L.; Bialkowska, H.; Billmeier, A.; Blume, C.; Boimska, B.; Botje, M.; Bracinik, J.; Bramm, R.; Brun, R.; Buncic, P.; Cerny, V.; Christakoglou, P.; Chvala, O.; Cramer, J.G.; Csato, P.; Darmenov, N.; Dimitrov, A.; Dinkelaker, P.; Eckardt, V.; Farantatos, G.; Fodor, Z.; Foka, P.; Freund, P.; Friese, V.; Gal, J.; Gazdzicki, M.; Georgopoulos, G.; Gladysz, E.; Grebieszkow, K.; Hegyi, S.; Hohne, C.; Kadija, K.; Karev, A.; Kliemant, M.; Kniege, S.; Kolesnikov, V.I.; Kollegger, T.; Kornas, E.; Korus, R.; Kowalski, M.; Kraus, I.; Kreps, M.; van Leeuwen, M.; Levai, P.; Litov, L.; Lungwitz, B.; Makariev, M.; Malakhov, A.I.; Markert, C.; Mateev, M.; Mayes, B.W.; Melkumov, G.L.; Meurer, C.; Mischke, A.; Mitrovski, M.; Molnar, J.; Mrowczynski, S.; Palla, G.; Panagiotou, A.D.; Panayotov, D.; Petridis, A.; Pikna, M.; Pinsky, Lawrence S.; Puhlhofer, F.; Reid, J.G.; Renfordt, R.; Richard, A.; Roland, C.; Roland, G.; Rybczynski, M.; Rybicki, A.; Sandoval, A.; Sann, H.; Schmitz, N.; Seyboth, P.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Stefanek, G.; Stock, R.; Strobele, H.; Susa, T.; Szentpetery, I.; Sziklai, J.; Trainor, T.A.; Trubnikov, V.; Varga, D.; Vassiliou, M.; Veres, G.I.; Vesztergombi, G.; Vranic, D.; Wetzler, A.; Wlodarczyk, Z.; Yoo, I.K.; Zaranek, J.; Zimanyi, J.

    2005-01-01

    The hadronic final state of central Pb+Pb collisions at 20, 30, 40, 80, and 158 AGeV has been measured by the CERN NA49 collaboration. The mean transverse mass of pions and kaons at midrapidity stays nearly constant in this energy range, whereas at lower energies, at the AGS, a steep increase with beam energy was measured. Compared to p+p collisions as well as to model calculations, anomalies in the energy dependence of pion and kaon production at lower SPS energies are observed. These findings can be explained, assuming that the energy density reached in central A+A collisions at lower SPS energies is sufficient to force the hot and dense nuclear matter into a deconfined phase.

  3. Contribution of the crystalline lens gradient refractive index to the accommodation amplitude in non-human primates: in vitro studies.

    Science.gov (United States)

    Maceo, Bianca M; Manns, Fabrice; Borja, David; Nankivil, Derek; Uhlhorn, Stephen; Arrieta, Esdras; Ho, Arthur; Augusteyn, Robert C; Parel, Jean-Marie

    2011-11-30

    The purpose of this study was to determine the contribution of the gradient refractive index to the change in lens power in hamadryas baboon and cynomolgus monkey lenses during simulated accommodation in a lens stretcher. Thirty-six monkey lenses (1.4-14.1 years) and twenty-five baboon lenses (1.8-28.0 years) were stretched in discrete steps. At each stretching step, the lens back vertex power was measured and the lens cross-section was imaged with optical coherence tomography. The radii of curvature for the lens anterior and posterior surfaces were calculated for each step. The power of each lens surface was determined using refractive indices of 1.365 for the outer cortex and 1.336 for the aqueous. The gradient contribution was calculated by subtracting the power of the surfaces from the measured lens power. In all lenses, the contribution of the surfaces and gradient increased linearly with the amplitude of accommodation. The gradient contributes on average 65 ± 3% for monkeys and 66 ± 3% for baboons to the total power change during accommodation. When expressed in percent of the total power change, the relative contribution of the gradient remains constant with accommodation and age in both species. These findings are consistent with Gullstrand's intracapsular theory of accommodation.

  4. The dynamic landscape of the cell nucleus.

    Science.gov (United States)

    Austin, Christopher M; Bellini, Michel

    2010-01-01

    While the cell nucleus was described for the first time almost two centuries ago, our modern view of the nuclear architecture is primarily based on studies from the last two decades. This surprising late start coincides with the development of new, powerful strategies to probe for the spatial organization of nuclear activities in both fixed and live cells. As a result, three major principles have emerged: first, the nucleus is not just a bag filled with nucleic acids and proteins. Rather, many distinct functional domains, including the chromosomes, resides within the confines of the nuclear envelope. Second, all these nuclear domains are highly dynamic, with molecules exchanging rapidly between them and the surrounding nucleoplasm. Finally, the motion of molecules within the nucleoplasm appears to be mostly driven by random diffusion. Here, the emerging roles of several subnuclear domains are discussed in the context of the dynamic functions of the cell nucleus.

  5. Dynamics of hadron-nucleus interactions

    International Nuclear Information System (INIS)

    Wallace, S.J.

    1981-07-01

    Recent progress in diffraction theory shows that proton-nucleus scattering at nonforward angles is dominated by the interference of waves from two or more bright spots. Analytic formulas based on asymptotic theories of diffraction yield valuable new insights into the scattering and these formulas can be readily extended to illuminate the role of dynamical ingredients, i.e., the nucleon-nucleon amplitudes. The governing parameters of the diffraction and some direct connections between the observed cross sections and the input dynamics are reviewed. New information regarding the nucleon-nucleon parameters based on recent phase shift analyses show some systematic differences from the effective NN amplitudes which produce fits to proton-nucleus diffraction data. Recent progress in understanding the role of Δ-isobars in proton-nucleus dynamics is reviewed. 126 references

  6. MORPHOLOGICAL ASPECTS OF HUMAN LENS CAPSULES - A COMPARATIVE LM, SEM AND TEM EXAMINATION

    NARCIS (Netherlands)

    JONGEBLOED, WL; KALICHARAN, D; LOS, LI; VANDERVEEN, G; WORST, JGF

    1991-01-01

    Lens capsules of patients of advanced age, obtained after extracapsular cataract surgery, were carefully prepared for a combined LM, TEM and SEM investigation, after preliminary washing and mounting onto a holder in a buffer solution. After pre-fixation with GA, samples were postfixed for LM/TEM and

  7. [Representation and mathematical analysis of human crystalline lens].

    Science.gov (United States)

    Tălu, Stefan; Giovanzana, Stefano; Tălu, Mihai

    2011-01-01

    The surface of human crystalline lens can be described and analyzed using mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the lens. The mathematical models used in lens biomechanics allow the study and the behavior of crystalline lens on variables and complex dynamic loads. Also, the lens biomechanics has the potential to improve the results in the development of intraocular lenses and cataract surgery. The paper presents the most representative mathematical models currently used for the modeling of human crystalline lens, both optically and biomechanically.

  8. Development of Powerhouse Using Fresnel lens

    Directory of Open Access Journals (Sweden)

    Al-Dohani Nawar Saif

    2018-01-01

    Full Text Available Solar energy is an alternative source of renewable energy. Sultanate of Oman government showed initiation on utilization of solar energy for domestic and industrial applications. Fresnel lens is one of the methods to collect maximum energy by gathering heat of the sun in the concentrated form (using solar collectors. Earlier research work discloses that Fresnel lens gave better result in terms of power output and produces lower heat loss as compared to linear –parabolic solar collectors. In this work, development of a proto Fresnel lens power house was made to generate electricity. The focused heat from Fresnel lens was used to heat the molten salt in a heat exchanger to produce the steam. The generated steam was used to rotate the steam engine coupled to a generator. In the current work, a maximum power of 30 W was produced. In addition, comparative study was carried out regarding solar salts and heat exchanger materials to understand the Fresnel powerhouse performance. Overall the present study gave valuable information regarding usage of Fresnel lens for electricity generation in Oman.

  9. A lazy way to design infrared lens

    Science.gov (United States)

    Qiu, RongSheng; Wu, JianDong; Chen, LongJiang; Yu, Kun; Pang, HaoJun; Hu, BaiZhen

    2017-08-01

    We designed a compact middle-wave infrared (MWIR) lens with a large focal length ratio (about 1.5:1), used in the 3.7 to 4.8 μm range. The lens is consisted of a compact front group and a re-imaging group. Thanks to the compact front group configuration, it is possible to install a filter wheel mechanism in such a tight space. The total track length of the lens is about 50mm, which includes a 2mm thick protective window and a cold shield of 12mm. The full field of view of the lens is about 3.6°, and F number is less than 1.6, the image circle is about 4.6mm in diameter. The design performance of the lens reaches diffraction limitation, and doesn't change a lot during a temperature range of -40°C +60°C. This essay proposed a stepwise design method of infrared optical system guided by the qualitative approach. The method fully utilize the powerful global optimization ability, with a little effort to write code snippet in optical design software, frees optical engineer from tedious calculation of the original structure.

  10. TESS Lens-Bezel Assembly Modal Testing

    Science.gov (United States)

    Dilworth, Brandon J.; Karlicek, Alexandra

    2017-01-01

    The Transiting Exoplanet Survey Satellite (TESS) program, led by the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT) will be the first-ever spaceborne all-sky transit survey. MIT Lincoln Laboratory is responsible for the cameras, including the lens assemblies, detector assemblies, lens hoods, and camera mounts. TESS is scheduled to be launched in August of 2017 with the primary goal to detect small planets with bright host starts in the solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed. The TESS payload consists of four identical cameras and a data handling unit. Each camera consists of a lens assembly with seven optical elements and a detector assembly with four charge-coupled devices (CCDs) including their associated electronics. The optical prescription requires that several of the lenses are in close proximity to a neighboring element. A finite element model (FEM) was developed to estimate the relative deflections between each lens-bezel assembly under launch loads to predict that there are adequate clearances preventing the lenses from making contact. Modal tests using non-contact response measurements were conducted to experimentally estimate the modal parameters of the lens-bezel assembly, and used to validate the initial FEM assumptions. Key Words Non-contact measurements, modal analysis, model validation

  11. Objective automated quantification of fluorescence signal in histological sections of rat lens.

    Science.gov (United States)

    Talebizadeh, Nooshin; Hagström, Nanna Zhou; Yu, Zhaohua; Kronschläger, Martin; Söderberg, Per; Wählby, Carolina

    2017-08-01

    Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  12. Direct projection from the suprachiasmatic nucleus to hypophysiotrophic corticotropin-releasing factor immunoreactive cells in the paraventricular nucleus of the hypothalamus demonstrated...

    DEFF Research Database (Denmark)

    Vrang, N.; Larsen, P.J.; Mikkelsen, J.D.

    1995-01-01

    Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry......Suprachiasmatic nucleus, paraventricular nucleus, circadian rhythms, phaseolus vulgaris-leucoagglutinin, corticotropin-releasing factor, dual immunocytochemistry...

  13. Radiation-induced eye lens changes and risk for cataract in interventional cardiology.

    Science.gov (United States)

    Ciraj-Bjelac, O; Rehani, M; Minamoto, A; Sim, K H; Liew, H B; Vano, E

    2012-01-01

    Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings. To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology. The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice. The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively. This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff. Copyright © 2012 S. Karger AG, Basel.

  14. Evaluation of Artisan aphakic intraocular lens in cases of pediatric aphakia with insufficient capsular support.

    Science.gov (United States)

    Gawdat, Ghada I; Taher, Sameh G; Salama, Marwa M; Ali, Adel A

    2015-06-01

    To evaluate the visual outcomes and complications after Artisan iris-claw lens implantation in aphakic children with insufficient capsular support. In this prospective, interventional noncontrolled study, aphakic eyes of consecutive patients >2 years of age with insufficient capsular support who underwent Artisan intraocular lens (IOL) implantation between June 2011 and December 2012 were followed for 1 year. Patients with anterior chamber depth IOL were included, 18 eyes with subluxated lens and 7 following trauma. The mean preoperative logMAR best-corrected visual acuity for traumatic aphakic patients was 0.95 ± 0.36; for patients with subluxation, 0.7 ± 0.26. Values improved at 1 year to 0.38 ± 0.15 (P IOL implantation for pediatric aphakia achieved a good visual outcome. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

  15. Terahertz lens made out of natural stone.

    Science.gov (United States)

    Han, Daehoon; Lee, Kanghee; Lim, Jongseok; Hong, Sei Sun; Kim, Young Kie; Ahn, Jaewook

    2013-12-20

    Terahertz (THz) time-domain spectroscopy probes the optical properties of naturally occurring solid aggregates of minerals, or stones, in the THz frequency range. Refractive index and extinction coefficient measurement reveals that most natural stones, including mudstone, sandstone, granite, tuff, gneiss, diorite, slate, marble, and dolomite, are fairly transparent for THz frequency waves. Dolomite in particular exhibits a nearly uniform refractive index of 2.7 over the broad frequency range from 0.1 to 1 THz. The high index of refraction allows flexibility in lens designing with a shorter accessible focal length or a thinner lens with a given focal length. Good agreement between the experiment and calculation for the THz beam profile confirms that dolomite has high homogeneity as a lens material, suggesting the possibility of using natural stones for THz optical elements.

  16. Catadioptric aberration correction in cathode lens microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tromp, R.M. [IBM T.J. Watson Research Center, PO Box 218, Yorktown Heights, NY 10598 (United States); Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Niels Bohrweg 2, 2333 CA Leiden (Netherlands)

    2015-04-15

    In this paper I briefly review the use of electrostatic electron mirrors to correct the aberrations of the cathode lens objective lens in low energy electron microscope (LEEM) and photo electron emission microscope (PEEM) instruments. These catadioptric systems, combining electrostatic lens elements with a reflecting mirror, offer a compact solution, allowing simultaneous and independent correction of both spherical and chromatic aberrations. A comparison with catadioptric systems in light optics informs our understanding of the working principles behind aberration correction with electron mirrors, and may point the way to further improvements in the latter. With additional developments in detector technology, 1 nm spatial resolution in LEEM appears to be within reach. - Highlights: • The use of electron mirrors for aberration correction in LEEM/PEEM is reviewed. • A comparison is made with similar systems in light optics. • Conditions for 1 nm spatial resolution are discussed.

  17. Freeform micromachining of an infrared Alvarez lens

    Science.gov (United States)

    Smilie, Paul J.; Dutterer, Brian S.; Lineberger, Jennifer L.; Davies, Matthew A.; Suleski, Thomas J.

    2011-02-01

    In 1967, Luis Alvarez introduced a novel concept for a focusing lens whereby two transmitting elements with cubic polynomial surfaces yield a composite lens of variable focal length with small lateral shifts. Computer simulations have demonstrated the behavior of these devices, but fabricating the refractive cubic surfaces of the types needed with adequate precision and depth modulation has proven to be challenging using standard methods, and, to the authors' knowledge, Alvarez lens elements have not been previously machined in infrared materials. Recent developments in freeform diamond machining capability have enabled the fabrication of such devices. In this paper, we discuss the fabrication of freeform refractive Alvarez elements in germanium using diamond micro-milling on a five-axis Moore Nanotech® 350FG Freeform Generator. Machining approaches are discussed, and measurements of surface figure and finish are presented. Initial experimental tests of optical performance are also discussed.

  18. Invited review article: the electrostatic plasma lens.

    Science.gov (United States)

    Goncharov, Alexey

    2013-02-01

    The fundamental principles, experimental results, and potential applications of the electrostatic plasma lens for focusing and manipulating high-current, energetic, heavy ion beams are reviewed. First described almost 50 years ago, this optical beam device provides space charge neutralization of the ion beam within the lens volume, and thus provides an effective and unique tool for focusing high current beams where a high degree of neutralization is essential to prevent beam blow-up. Short and long lenses have been explored, and a lens in which the magnetic field is provided by rare-earth permanent magnets has been demonstrated. Applications include the use of this kind of optical tool for laboratory ion beam manipulation, high dose ion implantation, heavy ion accelerator injection, in heavy ion fusion, and other high technology.

  19. Characterization of lens based photoacoustic imaging system

    Directory of Open Access Journals (Sweden)

    Kalloor Joseph Francis

    2017-12-01

    Full Text Available Some of the challenges in translating photoacoustic (PA imaging to clinical applications includes limited view of the target tissue, low signal to noise ratio and the high cost of developing real-time systems. Acoustic lens based PA imaging systems, also known as PA cameras are a potential alternative to conventional imaging systems in these scenarios. The 3D focusing action of lens enables real-time C-scan imaging with a 2D transducer array. In this paper, we model the underlying physics in a PA camera in the mathematical framework of an imaging system and derive a closed form expression for the point spread function (PSF. Experimental verification follows including the details on how to design and fabricate the lens inexpensively. The system PSF is evaluated over a 3D volume that can be imaged by this PA camera. Its utility is demonstrated by imaging phantom and an ex vivo human prostate tissue sample.

  20. Characterization of lens based photoacoustic imaging system.

    Science.gov (United States)

    Francis, Kalloor Joseph; Chinni, Bhargava; Channappayya, Sumohana S; Pachamuthu, Rajalakshmi; Dogra, Vikram S; Rao, Navalgund

    2017-12-01

    Some of the challenges in translating photoacoustic (PA) imaging to clinical applications includes limited view of the target tissue, low signal to noise ratio and the high cost of developing real-time systems. Acoustic lens based PA imaging systems, also known as PA cameras are a potential alternative to conventional imaging systems in these scenarios. The 3D focusing action of lens enables real-time C-scan imaging with a 2D transducer array. In this paper, we model the underlying physics in a PA camera in the mathematical framework of an imaging system and derive a closed form expression for the point spread function (PSF). Experimental verification follows including the details on how to design and fabricate the lens inexpensively. The system PSF is evaluated over a 3D volume that can be imaged by this PA camera. Its utility is demonstrated by imaging phantom and an ex vivo human prostate tissue sample.

  1. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad

    2016-12-19

    The gain of an antenna can be enhanced through the integration of a lens, however this technique has traditionally been restricted to planar antennas due to fabrication limitations of standard manufacturing processes. Here, with a unique combination of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a Fresnel lens enhances the gain of a 2-turn helix by around 4.6 dB giving a peak gain of about 12.9 dBi at 8.8 GHz.

  2. Ocular surface and tear film status among contact lens wearers and non-wearers who use VDT at work: comparing three different lens types.

    Science.gov (United States)

    Tauste, Ana; Ronda, Elena; Baste, Valborg; Bråtveit, Magne; Moen, Bente E; Seguí Crespo, María-Del-Mar

    2018-04-01

    To analyze differences in the ocular surface appearance and tear film status of contact lens wearers and non-wearers in a group of visual display terminals (VDT) workers and additionally to assess differences between lens materials. Cross-sectional study of 236 office workers, of whom 92 were contact lens wearers. Workers provided information on their contact lenses (conventional hydrogel, silicone hydrogel or rigid gas permeable lenses) and exposure to VDT at work. Ocular surface and tear film status were determined by the presence of bulbar, limbal and lid redness, lid roughness and corneal staining type, and by Schirmer's and tear break-up time tests (TBUT). A generalized linear model was used to calculate the crude (cRR) and age- and sex-adjusted (aRR) relative risk to measure the association between ocular surface and tear film abnormalities and contact lens use and type. The aRR of ocular surface abnormalities was higher in contact lens wearers compared to non-wearers: bulbar redness (aRR 1.69; 95% CI 1.25-2.30), limbal redness (aRR 2.87; 1.88-4.37), lid redness (aRR 2.53; 1.35-4.73) and lid roughness (aRR 7.03; 1.31-37.82). VDT exposure > 4 h/day increased wearers' risk of limbal and lid redness. Conventional hydrogel wearers had the highest risk of ocular surface abnormalities, followed by silicone hydrogel wearers. Both contact and non-contact lens wearers had a high prevalence of altered TBUT (77.3 and 75.7% respectively) and Schirmer (51.8 and 41.3%). Regular contact lens use during VDT exposure at work increases risk of bulbar, limbal and lid redness, and lid roughness, especially in soft contact lens wearers. The high prevalence of altered TBUT and Schirmer's results in all participants suggests that VDT use greatly affects tear film characteristics.

  3. Experimental search for compression phenomena in fast nucleus--nucleus collisions

    International Nuclear Information System (INIS)

    Schopper, E.; Baumgardt, H.G.; Obst, E.

    1977-01-01

    The occurrence of compression phenomena and shock waves, connected with the increase of the density of the nuclear matter during the interpenetration of two fast nuclei, are discussed. Current experiments dealing with this problem are reviewed. Before considering the mechanism of the interpenetration of two fast nuclei it may be useful to look at more simple situations, i.e., proton-proton interactions, then to envelop them with nuclear matter, considering proton-nucleus interactions. Only very general features are described, which may give suggestions for the understanding of the nucleus-nucleus impact

  4. TWO-PHOTON PHYSICS IN NUCLEUS-NUCLEUS COLLISIONS AT RHIC

    International Nuclear Information System (INIS)

    Nystrand, J.; Klein, S.

    1998-01-01

    Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear fields. Interactions between these fields in peripheral nucleus-nucleus collisions can probe many interesting physics topics. This presentation will focus on coherent two-photon and photonuclear processes at RHIC. The rates for these interactions will be high. The coherent coupling of all the protons in the nucleus enhances the equivalent photon flux by a factor Z 2 up to an energy of ∼ 3 GeV. The plans for studying coherent interactions with the STAR experiment will be discussed. Experimental techniques for separating signal from background will be presented

  5. Two-photon physics in nucleus-nucleus collisions at RHIC

    International Nuclear Information System (INIS)

    Nystrand, J.; Klein, S.

    1998-01-01

    Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear fields. Interactions between these fields in peripheral nucleus-nucleus collisions can probe many interesting physics topics. This presentation will focus on coherent two-photon and photonuclear processes at RHIC. The rates for these interactions will be high. The coherent coupling of all the protons in the nucleus enhances the equivalent photon flux by a factor Z 2 up to an energy of ∼ 3 GeV. The plans for studying coherent interactions with the STAR experiment will be discussed. Experimental techniques for separating signal from background will be presented

  6. Analytic models of plausible gravitational lens potentials

    International Nuclear Information System (INIS)

    Baltz, Edward A.; Marshall, Phil; Oguri, Masamune

    2009-01-01

    Gravitational lenses on galaxy scales are plausibly modelled as having ellipsoidal symmetry and a universal dark matter density profile, with a Sérsic profile to describe the distribution of baryonic matter. Predicting all lensing effects requires knowledge of the total lens potential: in this work we give analytic forms for that of the above hybrid model. Emphasising that complex lens potentials can be constructed from simpler components in linear combination, we provide a recipe for attaining elliptical symmetry in either projected mass or lens potential. We also provide analytic formulae for the lens potentials of Sérsic profiles for integer and half-integer index. We then present formulae describing the gravitational lensing effects due to smoothly-truncated universal density profiles in cold dark matter model. For our isolated haloes the density profile falls off as radius to the minus fifth or seventh power beyond the tidal radius, functional forms that allow all orders of lens potential derivatives to be calculated analytically, while ensuring a non-divergent total mass. We show how the observables predicted by this profile differ from that of the original infinite-mass NFW profile. Expressions for the gravitational flexion are highlighted. We show how decreasing the tidal radius allows stripped haloes to be modelled, providing a framework for a fuller investigation of dark matter substructure in galaxies and clusters. Finally we remark on the need for finite mass halo profiles when doing cosmological ray-tracing simulations, and the need for readily-calculable higher order derivatives of the lens potential when studying catastrophes in strong lenses

  7. Photonic crystal based polarization insensitive flat lens

    International Nuclear Information System (INIS)

    Turduev, M; Bor, E; Kurt, H

    2017-01-01

    The paper proposes a new design of an inhomogeneous artificially created photonic crystal lens structure consisting of annular dielectric rods to efficiently focus both transverse electric and transverse magnetic polarizations of light into the same focal point. The locations of each individual cell that contains the annular dielectric rods are determined according to a nonlinear distribution function. The inner and outer radii of the annular photonic dielectric rods are optimized with respect to the polarization insensitive frequency response of the transmission spectrum of the lens structure. The physical background of the polarization insensitive focusing mechanism is investigated in both spatial and frequency domains. Moreover, polarization independent wavefront transformation/focusing has been explored in detail by investigating the dispersion relation of the structure. Corresponding phase index distribution of the lens is attained for polarization insensitive normalized frequency range of a / λ   =  0.280 and a / λ   =  0.300, where a denotes the lattice constant of the designed structure and λ denotes the wavelength of the incident light. We show the wave transformation performance and focal point movement dynamics for both polarizations of the lens structure by specially adjusting the length of the structure. The 3D finite-difference time domain numerical analysis is also performed to verifiy that the proposed design is able to focus the wave regardless of polarization into approximately the same focal point (difference between focal distances of both polarizations stays below 0.25 λ ) with an operating bandwidth of 4.30% between 1476 nm and 1541 nm at telecom wavelengths. The main superiorities of the proposed lens structure are being all dielectric and compact, and having flat front and back surfaces, rendering the proposed lens design more practical in the photonic integration process in various applications such as optical switch

  8. Effect of infrared radiation on the lens

    Directory of Open Access Journals (Sweden)

    Aly Eman

    2011-01-01

    Full Text Available Background: Infrared (IR radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye. Aim : The present study was designed to investigate the effect of IR radiation on rabbit′s crystalline lens and lens membrane. Materials and Methods: Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na + -K + ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared (FTIR spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001. Results: The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na + -K + ATPase significantly decreased for all groups. Conclusions: The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

  9. ANALYTICAL SOLUTIONS OF SINGULAR ISOTHERMAL QUADRUPOLE LENS

    International Nuclear Information System (INIS)

    Chu Zhe; Lin, W. P.; Yang Xiaofeng

    2013-01-01

    Using an analytical method, we study the singular isothermal quadrupole (SIQ) lens system, which is the simplest lens model that can produce four images. In this case, the radial mass distribution is in accord with the profile of the singular isothermal sphere lens, and the tangential distribution is given by adding a quadrupole on the monopole component. The basic properties of the SIQ lens have been studied in this Letter, including the deflection potential, deflection angle, magnification, critical curve, caustic, pseudo-caustic, and transition locus. Analytical solutions of the image positions and magnifications for the source on axes are derived. We find that naked cusps will appear when the relative intensity k of quadrupole to monopole is larger than 0.6. According to the magnification invariant theory of the SIQ lens, the sum of the signed magnifications of the four images should be equal to unity, as found by Dalal. However, if a source lies in the naked cusp, the summed magnification of the left three images is smaller than the invariant 1. With this simple lens system, we study the situations where a point source infinitely approaches a cusp or a fold. The sum of the magnifications of the cusp image triplet is usually not equal to 0, and it is usually positive for major cusps while negative for minor cusps. Similarly, the sum of magnifications of the fold image pair is usually not equal to 0 either. Nevertheless, the cusp and fold relations are still equal to 0 in that the sum values are divided by infinite absolute magnifications by definition.

  10. Intraocular Lens Calcification; a Clinicopathologic Report

    Directory of Open Access Journals (Sweden)

    Mozhgan Rezaei-Kanavi

    2009-04-01

    Full Text Available

    PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

  11. Comparison of clear lens extraction and collamer lens implantation in high myopia

    Directory of Open Access Journals (Sweden)

    Ahmed M Emarah

    2010-05-01

    Full Text Available Ahmed M Emarah, Mostafa A El-Helw, Hazem M YassinCairo University, Cairo, EgyptAim: To compare the outcomes of clear lens extraction and collamer lens implantation in high myopia.Patients and methods: Myopic patients younger than 40 years old with more than 12 diopters of myopia or who were not fit for laser-assisted in situ keratomileusis were included. Group 1 comprised patients undergoing clear lens extraction and Group 2 patients received the Visian implantable collamer lens. Outcome and complications were evaluated.Results: Postoperative best corrected visual acuity was -0.61 ± 0.18 in Group 1 and 0.79 ± 0.16 in Group 2. In Group 1, 71.4% achieved a postoperative uncorrected visual acuity better than the preoperative best corrected visual acuity, while only 51.8% patients achieved this in Group 2. Intraocular pressure decreased by 12.55% in Group 1, and increased by 15.11% in Group 2. Corneal endothelial cell density decreased by 4.47% in Group 1 and decreased by 5.67% in Group 2. Posterior capsule opacification occurred in Group 1. In Group 2, lens opacification occurred in 11.11%, significant pigment dispersion in 3.7%, and pupillary block glaucoma in 3.7%.Conclusion: Clear lens extraction presents less of a financial load up front, and less likelihood of the need for a secondary intervention in the future. Clear lens extraction is a more viable solution in developing countries with limited financial resources.Keywords: clear lens extraction, implantable collamer lens, myopia

  12. Future prospects in N-nucleus interactions

    International Nuclear Information System (INIS)

    Moss, J.M.

    1983-01-01

    A detailed examination of two research areas, polarization observables and antiproton-nucleus reactions, which should have near-term future impact on the understanding of the interaction of medium-energy nucleons in nuclei is made. More speculative future experiments employing cooled beams, double spectrometer systems, and large Q-value, low momentum-transfer reactions are also discussed. 25 references, 4 figures

  13. Consequences of hadron-nucleus multiplicity parametrization

    International Nuclear Information System (INIS)

    Singh, C.P.; Shyam, M.

    1986-01-01

    Some interesting consequences are analyzed of a new parametrization for the hadron-nucleus multiplicity distributions and they are compared with the experimental data. Further, it is illustrated how the scaling property for the average multiplicity will be modified and it is found that the experimental data support this behaviour. (orig.)

  14. High energy hadron-nucleus scattering

    International Nuclear Information System (INIS)

    Koplik, J.; Mueller, A.H.

    1975-01-01

    Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models

  15. Large philipsite crystal as ferromanganese nodule nucleus

    Digital Repository Service at National Institute of Oceanography (India)

    Ghosh, A.K.; Mukhopadhyay, R.

    nodule accretion as approximately 2 mm/Ma and that of phillipsite growth as approximately 0.65 mm/Ka, the nucleus material appears to have been growing for approximately 4.5-5 Ma. Originally surfaced as a rock fragment from late Miocene volcanism...

  16. Correlations in hadron-nucleus collisions

    International Nuclear Information System (INIS)

    Wosiek, B.

    1976-09-01

    The correlations between the particles produced in interactions of hadrons with emulsion nuclei were investigated. The data are in qualitative agreement with the models which describe the interactions with nuclei as subsequent collisions of the fast part of excited hadronic matter inside the nucleus. (author)

  17. Inside a plant nucleus: discovering the proteins

    Czech Academy of Sciences Publication Activity Database

    Petrovská, Beáta; Šebela, M.; Doležel, Jaroslav

    2015-01-01

    Roč. 66, č. 6 (2015), s. 1627-1640 ISSN 0022-0957 R&D Projects: GA ČR(CZ) GA14-28443S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Cell nucleus * chromatin * genome function Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.677, year: 2015

  18. Iliacus Abscess with Radiculopathy Mimicking Herniated Nucleus ...

    African Journals Online (AJOL)

    2016-05-02

    May 2, 2016 ... radiculopathy mimicking herniated nucleus pulposus: Aadditional diagnostic value of magnetic resonance imaging. Niger J Clin Pract. 2017;20:392-3. This is an open access article distributed under the terms of the Creative Commons. Attribution-Non Commercial-Share Alike 3.0 License, which allows ...

  19. Resonances in η-light nucleus systems

    Indian Academy of Sciences (India)

    We locate resonances in -light nucleus elastic scattering using the time delay method. We solve few-body equations within the finite rank approximation in order to calculate the -matrices and hence the time delay for the - 3He and - 4He systems. We find a resonance very close to the threshold in - 3 He elastic ...

  20. Compound nucleus studies withy reverse kinematics

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1985-06-01

    Reverse kinematics reactions are used to demonstrate the compound nucleus origin of intermediate mass particles at low energies and the extension of the same mechanism at higher energies. No evidence has appeared in our energy range for liquid-vapor equilibrium or cold fragmentation mechanisms. 11 refs., 12 figs

  1. Liquid lens: advances in adaptive optics

    Science.gov (United States)

    Casey, Shawn Patrick

    2010-12-01

    'Liquid lens' technologies promise significant advancements in machine vision and optical communications systems. Adaptations for machine vision, human vision correction, and optical communications are used to exemplify the versatile nature of this technology. Utilization of liquid lens elements allows the cost effective implementation of optical velocity measurement. The project consists of a custom image processor, camera, and interface. The images are passed into customized pattern recognition and optical character recognition algorithms. A single camera would be used for both speed detection and object recognition.

  2. Pulse transformer for the AA lithium lens

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    The antiprotons emanating from the target were initially focused by a magnetic horn. Later on, a Li-lens was used during operation for the SPS collider, until 1992. A Li-rod (130 mm long, 34 mm in diameter) constituted the secondary of a 1:23 pulse-transformer. The half-sine pulse rose to 1000 kA in 900 microsec. The angular acceptance was 95 mrad. In operation after 1992, for LEAR only, a more modest Li-lens was used (155 mm long, diameter 20 mm, 480 kA, risetime 240 microsec, angular acceptance 75 mrad).

  3. Herniation of the anterior lens capsule

    Directory of Open Access Journals (Sweden)

    Pereira Nolette

    2007-01-01

    Full Text Available Herniation of the anterior lens capsule is a rare abnormality in which the capsule bulges forward in the pupillary area. This herniation can be mistaken for an anterior lenticonus where both the capsule and the cortex bulge forward. The exact pathology behind this finding is still unclear. We report the clinical, ultrasound biomicroscopy (UBM and histopathological findings of a case of herniation of the anterior lens capsule. UBM helped to differentiate this entity from anterior lenticonus. Light microscopy revealed capsular splitting suggestive of capsular delamination and collection of fluid (aqueous in the area of herniation giving it a characteristic appearance.

  4. Immunochemical analyses of soluble lens proteins in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens proteins of 10 fishes, belonging to the families Clupeidae, Hemirhamphidae, Lactaridae, Scombridae, Stromatidae, Psettodidae, Bothidae and Soleidae were studied by immunoelectrophoresis using the lens antiserum of Sardinella...

  5. Formation of proton-fragments in hadron-nucleus and nucleus-nucleus collisions at high energies

    International Nuclear Information System (INIS)

    Bazarov, E.Kh.; Olimov, K.; Petrov, V.I.; Lutpullaev, S.L.

    2006-01-01

    Full text: The investigation of production of protons in hadron- and nucleus-nucleus interactions is a key problem allowing one to establish the singularities of dynamics of nuclear interactions. The formation of proton-fragments at high energies of colliding particles proceeds within both the interaction of hadrons with nuclei and in the process of decay of the nucleus or its de-excitation at peripheral interactions. At different stages of interaction of impinging particle with target nucleus, the different mechanisms of formation of proton-fragments: the direct knock-out of intranuclear nucleons in the process of high energy cascade of an initial hadron, intranuclear cascade of produced particles, decay of the excited multi-nucleon fragments and of the thermalized remnant nucleus, and the coalescence of nuclear fragments to the new clusters are realized with the certain probability, connected to the interaction parameters (the interaction energy, the parameter of collision, the intranuclear density, the configuration of Fermi momentum of nucleons and clusters of target nucleus et al.). In its turn, the mechanisms of formation of the final nuclear fragments are closely related to the type of excitation of an initial nucleus. The peripheral interactions proceed at small transfers of the momentum of an impinging particle and represent the wide class of reactions covering the processes from diffractive or coulomb collective excitations of the whole nucleus to the direct quasi-elastic knock-out of the separate nucleons. Non-peripheral interactions are caused by comparatively high local transfers of momentum to the intranuclear clusters allowing the development of intranuclear cascade and the asymmetric redistribution of energy of an impinging particle. The central collisions causing the full decay of nucleus on nucleons or few-nucleon fragments, are the limiting case of the maximal development of the intranuclear cascade. The interaction of the initial particles with

  6. Subluxation of the crystalline lens: a no-ring approach.

    Science.gov (United States)

    Rodrigues, Antonio Carlos L; Trivedi, Rupal H; Wilson, M Edward

    2012-01-01

    To report the surgical technique and outcomes of a no-ring approach to posterior chamber intraocular lens (IOL) implantation in children and young adults with subluxation of the crystalline lens. A three-piece 5.5-mm hydrophobic acrylic IOL was implanted in which the optic and one haptic were inside the capsular bag and the other haptic was in the ciliary sulcus. The implantations were done in 13 eyes of 10 patients with lens subluxation. One haptic was fixated in the ciliary sulcus by passing it through an operculum-shaped opening in the capsular bag edge, made between 2 and 3 clock hours, clockwise from the middle point of the subluxated area. The mean age of the 10 patients was 12.61 ± 8.04 years and the mean follow-up was 21.38 ± 11.29 months. The mean preoperative and postoperative best-corrected visual acuity (BCVA) was 1.15 ± 0.58 and 0.37 ± 0.17 logarithm of the minimum angle of resolution, respectively, in 11 measured eyes. The postoperative BCVA was 20/40 or better in 4 eyes (36.36%), between 20/40 and 20/60 in 6 eyes (54.54%), and between 20/80 and 20/100 in 1 eye (9.09%). The BCVA improved in all eyes. Postoperative IOL decentration between 1.0 and 1.5 mm occurred in 3 of 13 eyes (23.08%). The results indicate that the no-ring technique allows centration of an IOL implanted into a subluxated capsular bag without using capsule tension rings. Copyright 2012, SLACK Incorporated.

  7. Chapter 03: Correct use of a hand lens

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    A hand lens is a powerful tool for the identification of wood, but like all tools it must be used correctly to take full advantage of its powers. The hand lens has two main parts, a lens that magnifies the object of interest (generally we use 10X or 14X lenses in wood identification; a 14X lens is recommended for use with this manual) and a housing to hold and protect...

  8. Suprachiasmatic Nucleus Interaction with the Arcuate Nucleus; Essential for Organizing Physiological Rhythms

    NARCIS (Netherlands)

    Buijs, Frederik N.; Guzmán-Ruiz, Mara; León-Mercado, Luis; Basualdo, Mari Carmen; Escobar, Carolina; Kalsbeek, Andries; Buijs, Ruud M.

    2017-01-01

    The suprachiasmatic nucleus (SCN) is generally considered the master clock, independently driving all circadian rhythms. We recently demonstrated the SCN receives metabolic and cardiovascular feedback adeptly altering its neuronal activity. In the present study, we show that microcuts effectively

  9. The suprachiasmatic nucleus-paraventricular nucleus interactions: a bridge to the neuroendocrine and autonomic nervous system

    NARCIS (Netherlands)

    Buijs, R. M.; Hermes, M. H.; Kalsbeek, A.

    1998-01-01

    Vasopressin (VP) is one of the principal neurotransmitters of the suprachiasmatic nucleus (SCN). By means of anatomical, physiological and electrophysiological techniques we have demonstrated that VP containing pathways from the SCN serve to affect neuroendocrine and 'autonomic' neurons in the

  10. Effective nucleus-nucleus potentials derived from the generator coordinate method

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, H; Canto, L F [Oxford Univ. (UK). Dept. of Theoretical Physics

    1977-11-07

    The equivalence of the generator coordinate method (GCM) and the resonating group method (RGM) and the formal equivalence of the RGM and the orthogonality condition model (OCM) lead to a relation connecting the effective nucleus-nucleus potentials of the OCM with matrix elements of the GCM. This relation may be used to derive effective nucleus-nucleus potentials directly from GCM matrix elements without explicit reference to the potentials of the RGM. In a first application local and l-independent effective potentials are derived from diagonal GCM matrix elements which represent the energy surfaces of a two-centre shell model. Using these potentials the OCM can reproduce the results of a full RGM calculation very well for the elastic scattering of two ..cap alpha..-particles and fairly well for elastic /sup 16/O-/sup 16/O scattering.

  11. Outcomes Associated With Concurrent Iris-Sutured Intraocular Lens Placement and Subluxated Crystalline Lens Extraction.

    Science.gov (United States)

    McClellan, Scott F; Soiberman, Uri; Gehlbach, Peter L; Murakami, Peter N; Stark, Walter J

    2015-08-01

    We have developed a novel surgical technique, to our knowledge, for the management of subluxated crystalline lenses involving preplacement of an iris-sutured posterior chamber intraocular lens (PCIOL) before pars plana vitrectomy and lensectomy. To investigate the outcomes of eyes with subluxated crystalline lenses, predominantly a result of Marfan syndrome (14 eyes [58%]) or trauma (5 eyes [21%]), that underwent pars plana vitrectomy and lensectomy with placement of an iris-sutured PCIOL. We performed a retrospective, noncomparative case series of 24 eyes from 17 consecutive adult patients with surgically treated subluxated crystalline lenses presenting to the Wilmer Eye Institute at Johns Hopkins Hospital from October 6, 2006, through May 1, 2013. The mean (SD) postoperative follow-up was 24.4 (20.5) months for eyes with at least 6 months of follow-up (last date, October 13, 2014). We performed the analysis from January 21, 2014, through January 3, 2015. Improvement in best-corrected visual acuity using an automated Snellen chart and induction of astigmatism for eyes with at least 6 months of follow-up (n = 18) and IOL stability during follow-up for all eyes (n = 24). The mean (SD) age at surgery was 49.4 (10.7 [range, 29-67]) years. We found an improvement in mean (SD [95% CI]) best-corrected visual acuity from 0.66 (0.71 [0.30-1.02]) logMAR preoperatively (Snellen equivalent, approximately 20/90; range, 20/30 to hand motions) to 0.07 (0.11 [95% CI, 0.01-0.12]) logMAR postoperatively (Snellen equivalent, approximately 20/23; range, 20/15 to 20/50). We found little change in astigmatism postoperatively (mean change, -0.1 [95% CI, -0.5 to 0.13] diopters). Postoperative complications included retinal detachment (1 eye [4%]), retained cortical fragment (1 [4%]), cystoid macular edema (2 [8%]), and IOL subluxation (3 [13%]) owing to haptic slippage within 3 months of the procedure. The overall probability of successfully achieving placement of a centered iris

  12. MR findings of degenerative changes of nucleus pulposus in lumbar spine: sequential changes after disc herniation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Joon [Choong-Ang Gil Hospital, Seoul (Korea, Republic of); Cha, Yoo Mi; Hwang, Hee Young [College of Medicine, Dankook University, Chenoan (Korea, Republic of)

    1994-04-15

    To evaluate the relationship between MR changes of the nucleus pulposus and the time interval after traumatic disc herniation. T2-weighted MR images of 132 patients with back pain and/or sciatica were reviewed. The changes of signal intensity, central cleft and height of the nucleus pulposus were used as criteria of disc degeneration and they were graded as normal, mild, moderate and severe degree of degeneration. Putting these criteria together we provided integrated grade of degeneration of the nucleus pulposus(grade 0-3). To get the preliminary data for normal and age-related disc degeneration, we measured the disc height by age groups and disc levels and analyzed the relationship between the age of the patients and the signal intensity, cleft and height in normal disc levels of the 132 patients. In 68 patients of 88 levels disc herniation, we analyzed the relationship between symptom duration and the degree of degeneration. Among these 68 patients we selected 14 patients(16 levels) who were under 30 years of age and had history of recent trauma to minimize data distortion from age related degeneration and ambiguity of initiation point of degeneration. In this group we analyzed the relationship between the time period after traumatic disc herniation and the degree of degeneration. The age of the patient had close relationship with the grade of signal intensity, central cleft, and disc height and grade of degeneration of the nucleus pulposus in normal discs. In 88 levels of herniated discs, the duration of symptom and degree of degeneration showed moderate correlation. In 14 patients of disc herniation who were under 30 years old and had trauma history in recent 2 years, grade 1 disc degeneration occurred in average 3.7 months after trauma. Although it was difficult to proceed statistical analysis in the last group because of small patients number, the degree of degeneration of nucleus pulposus had close relationship with the duration after traumas or duration of

  13. MR findings of degenerative changes of nucleus pulposus in lumbar spine: sequential changes after disc herniation

    International Nuclear Information System (INIS)

    Kim, Sang Joon; Cha, Yoo Mi; Hwang, Hee Young

    1994-01-01

    To evaluate the relationship between MR changes of the nucleus pulposus and the time interval after traumatic disc herniation. T2-weighted MR images of 132 patients with back pain and/or sciatica were reviewed. The changes of signal intensity, central cleft and height of the nucleus pulposus were used as criteria of disc degeneration and they were graded as normal, mild, moderate and severe degree of degeneration. Putting these criteria together we provided integrated grade of degeneration of the nucleus pulposus(grade 0-3). To get the preliminary data for normal and age-related disc degeneration, we measured the disc height by age groups and disc levels and analyzed the relationship between the age of the patients and the signal intensity, cleft and height in normal disc levels of the 132 patients. In 68 patients of 88 levels disc herniation, we analyzed the relationship between symptom duration and the degree of degeneration. Among these 68 patients we selected 14 patients(16 levels) who were under 30 years of age and had history of recent trauma to minimize data distortion from age related degeneration and ambiguity of initiation point of degeneration. In this group we analyzed the relationship between the time period after traumatic disc herniation and the degree of degeneration. The age of the patient had close relationship with the grade of signal intensity, central cleft, and disc height and grade of degeneration of the nucleus pulposus in normal discs. In 88 levels of herniated discs, the duration of symptom and degree of degeneration showed moderate correlation. In 14 patients of disc herniation who were under 30 years old and had trauma history in recent 2 years, grade 1 disc degeneration occurred in average 3.7 months after trauma. Although it was difficult to proceed statistical analysis in the last group because of small patients number, the degree of degeneration of nucleus pulposus had close relationship with the duration after traumas or duration of

  14. Fast detector for triggering on charged particle multiplicity for relativistic nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Agakishiev, G.; Man'yakov, P.K.; Drees, A.

    1997-01-01

    The simple and fast detector of charged particle multiplicity for relativistic nucleus-nucleus collision studies is performed. The multiplicity detector has been designed for the first level trigger of the CERES/NA45 experiment to study Pb-Au collisions at CERN SPS energies. The detector has allowed a realization of the 40 ns trigger for selection of events with definite impact parameter. The construction, operation characteristics, method of calibration, and testing results are described in detail

  15. Random matrix theory and analysis of nucleus-nucleus collision at high energies

    International Nuclear Information System (INIS)

    Shahaliev, E.I.; Inst. of Radiation Problems, Baku; ); Kuznetsov, A.A.; Suleymanov, M.K.; ); Teryaev, O.V.; )

    2006-01-01

    A novel method for analysis of experimental data obtained at relativistic nucleus-nucleus collisions is proposed. The method, based on the ideas of Random Matrix Theory, is applied to detect systematic errors that occur at measurements of momentum distributions of emitted particles. The unfolded momentum distribution is well described by the Gaussian orthogonal ensemble of random matrices, when the uncertainty in the momentum distribution is maximal. The method is free from unwanted background contributions [ru

  16. Theory of and effects from elastoplasticity in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Noerenberg, W.; Technische Hochschule Darmstadt

    1985-02-01

    Elastoplasticity of finite Fermi systems results from a coherent coupling between collective and intrinsic degrees of freedom and subsequent equilibration essentially due to two-body collisions. Within a non-markovian transport-theoretical approach referred to as dissipative diabatic dynamics (DDD), elastoplastical forms the link between giant vibrations and overdamped motion of nuclear. Obersvable effects resulting from this non-markovian behaviour in nucleus-nucleus collisions are discussed. (orig.)

  17. Strangeness and charm production in nucleus-nucleus collisions at beam energies near the thresholds

    International Nuclear Information System (INIS)

    Senger, P.

    2001-01-01

    The creation of strangeness and charm in nucleus-nucleus collisions at threshold beam energies is discussed as a probe for compressed baryonic matter. Experimental data on strangeness production at SIS energies indicate that the properties of kaons and antikaons are modified in the dense nuclear medium. An experiment is proposed to explore the QCD phase diagram in the region of highest baryon densities. An important observable will be charm production close to threshold. (orig.)

  18. Nucleon molecular orbitals and the transition mechanism between molecular orbitals in nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Imanishi, B.; Misono, S.; von Oertzen, W.; Voit, H.

    1988-08-01

    The molecular orbitals of the nucleon(s) in nucleus-nucleus collisions are dynamically defined as a linear combination of nucleon single-particle orbits (LCNO) in a rotating frame by using the coupled-reaction-channel (CRC) theory. Nucleon molecular orbitals and the promotions of nucleon, - especially due to the Landau-Zener radial coupling are discussed with the method above mentioned. (author)

  19. Multi-quark effects in high energy nucleon-nucleon and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Besliu, C.; Caraciuc, I.; Jipa, A.; Olariu, A.; Topor-Pop, R.; Cotorobai, F.; Pantea, D.; Popa, L.; Popa, V.; Topor-Pop, V.

    1988-02-01

    Recent data obtained in two experiments performed in the framework of the Bucharest-Dubna collaboration are presented, i.e.: the observation of narrow dibaryonic resonances is neutron-proton interactions in 1mHBC at different momenta of incident neutrons in the range 1-5 GeV/c, and the cumulative production of negative pions in nucleus-nucleus interactions in SKM-200 streamer chamber at 4.5 GeV/c. (authors)

  20. 21 CFR 886.1405 - Ophthalmic trial lens set.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens set. 886.1405 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1405 Ophthalmic trial lens set. (a) Identification. An ophthalmic trial lens set is a device that is a set of lenses of various dioptric powers...

  1. 21 CFR 886.1420 - Ophthalmic lens gauge.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic lens gauge. 886.1420 Section 886.1420...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1420 Ophthalmic lens gauge. (a) Identification. An ophthalmic lens gauge is a calibrated device intended to manually measure the curvature of a...

  2. 21 CFR 886.1410 - Ophthalmic trial lens clip.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens clip. 886.1410 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1410 Ophthalmic trial lens clip. (a) Identification. An ophthalmic trial lens clip is a device intended to hold prisms, spheres, cylinders, or...

  3. 21 CFR 886.1380 - Diagnostic condensing lens.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic condensing lens. 886.1380 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1380 Diagnostic condensing lens. (a) Identification. A diagnostic condensing lens is a device used in binocular indirect ophthalmoscopy (a procedure...

  4. 21 CFR 886.1415 - Ophthalmic trial lens frame.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic trial lens frame. 886.1415 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1415 Ophthalmic trial lens frame. (a) Identification. An opthalmic trial lens frame is a mechanical device intended to hold trial lenses for vision...

  5. In vivo study of lens regeneration in Rana cyanophlyctis under ...

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Mar 12, 2014 ... enhanced the percentage lens regeneration not only in young tadpoles but also in froglets. Lens regeneration ability ... Influence of vitamin A and ascorbic acid on lens regeneration in young, mature tadpoles and froglets of the frog Rana cyanophlyctis. Group .... ingested by macrophages. Dorsal iris cells ...

  6. Vitrectorhexis and lens aspiration with posterior chamber intraocular lens implantation in spherophakia.

    Science.gov (United States)

    Al-Haddad, Christiane; Khatib, Lama

    2012-07-01

    We describe a technique that uses the vitrector to perform successful lens aspiration and posterior chamber intraocular lens (IOL) implantation in children with spherophakia and anterior lens subluxation. After an anterior chamber maintainer is placed, the ocutome is introduced through a limbal incision to perform a circular vitrectorhexis to avoid excessive manipulation of the unstable lens followed by gentle cortex aspiration. A foldable IOL is injected into the sulcus (3-piece IOL) or bag (1-piece IOL) if the capsule is sufficiently stable. Through a pars plana incision, the ocutome is then used to perform a posterior capsulotomy to prevent late posterior capsule opacification. In our patient, sulcus IOL placement was more stable than in-the-bag placement. Neither author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. ψ' and J/ψ suppression in high-energy nucleon-nucleus and nucleus-nucleus collisions

    International Nuclear Information System (INIS)

    Wong, Cheuk-Yin.

    1995-01-01

    The observed features of ψ' to J/ψ suppression in pA and nucleus-nucleus collisions can be explained in terms of a two-component absorption model. For the hard component of the absorption due to the interaction of the produced c bar c systems with baryons at high relative energies, the absorption cross sections are insensitive to the radii of the c bar c systems, as described by the Additive Quark Model. For the soft component due to the low energy c bar c interactions with soft particles produced by other baryon-baryon collisions, the absorption cross sections are greater for ψ' than for J/ψ, because the breakup threshold for ψ' is much smaller than for ψ

  8. 3D printed helical antenna with lens

    KAUST Repository

    Farooqui, Muhammad Fahad; Shamim, Atif

    2016-01-01

    of 3D and 2D inkjet printing of dielectric and metallic inks respectively, we demonstrate a Fresnel lens that has been monolithically integrated to a non-planar antenna (helix) for the first time. Antenna measurements show that the integration of a

  9. Corneal ring infiltration in contact lens wearers

    Directory of Open Access Journals (Sweden)

    Seyed Ali Tabatabaei

    2017-01-01

    Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

  10. Lens Ray Diagrams with a Spreadsheet

    Science.gov (United States)

    González, Manuel I.

    2018-01-01

    Physicists create spreadsheets customarily to carry out numerical calculations and to display their results in a meaningful, nice-looking way. Spreadsheets can also be used to display a vivid geometrical model of a physical system. This statement is illustrated with an example taken from geometrical optics: images formed by a thin lens. A careful…

  11. Electronic states in a quantum lens

    International Nuclear Information System (INIS)

    Rodriguez, Arezky H.; Trallero-Giner, C.; Ulloa, S. E.; Marin-Antuna, J.

    2001-01-01

    We present a model to find analytically the electronic states in self-assembled quantum dots with a truncated spherical cap (''lens'') geometry. A conformal analytical image is designed to map the quantum dot boundary into a dot with semispherical shape. The Hamiltonian for a carrier confined in the quantum lens is correspondingly mapped into an equivalent operator and its eigenvalues and eigenfunctions for the corresponding Dirichlet problem are analyzed. A modified Rayleigh-Schro''dinger perturbation theory is presented to obtain analytical expressions for the energy levels and wave functions as a function of the spherical cap height b and radius a of the circular cross section. Calculations for a hard wall confinement potential are presented, and the effect of decreasing symmetry on the energy values and eigenfunctions of the lens-shape quantum dot is studied. As the degeneracies of a semicircular geometry are broken for b≠a, our perturbation approach allows tracking of the split states. Energy states and electronic wave functions with m=0 present the most pronounced influence on the reduction of the lens height. The method and expressions presented here can be straightforwardly extended to deal with more general Hamiltonians, including strains and valence-band coupling effects in Group III--V and Group II--VI self-assembled quantum dots

  12. Method for producing an isoplanatic aspheric monofocal intraocular lens, and resul ting lens

    OpenAIRE

    Barbero, Sergio; Marcos, Susana; Dorronsoro, Carlos; Montejo, Javier; Salazar Salegui, Pedro

    2010-01-01

    [EN] The invention can be used to obtain isoplanatic aspheric mono focal intraocular lenses in a viewing range of up to 25° (preferably up to 10°). The method comprises the following steps: l. mathematical defmition of an aphakic eye model; 2. mathematical definition of an intraocular lens model; 3. mathematical defmition of the implantation of the lens; 4. mathematical defmition of the merit function; 5. definition of the contour conditions; 6. defmition of a measurement for charact...

  13. Properties of the cathode lens combined with a focusing magnetic/immersion-magnetic lens

    Czech Academy of Sciences Publication Activity Database

    Konvalina, Ivo; Müllerová, Ilona

    2011-01-01

    Roč. 645, č. 1 (2011), s. 55-59 ISSN 0168-9002 R&D Projects: GA ČR GAP102/10/1410; GA AV ČR IAA100650902; GA MŠk ED0017/01/01 Institutional research plan: CEZ:AV0Z20650511 Keywords : cathode lens * compound objective lens * aberration coefficients * spot size * field calculations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.207, year: 2011

  14. The Baryon Production and Baryon Number Transfer in Hadron-Hadron, Hadron-Nucleus and Nucleus-Nucleus Collisions

    International Nuclear Information System (INIS)

    Szymanski, P.

    2006-09-01

    This work concerns soft hadronic interactions which in the Standard Model carry most of the observable cross-section but are not amenable to quantitative predictions due to the very nature of the QCD (Theory of Strong Interactions). In the low momentum transfer region the evolving coupling constant caused perturbation theory to break down. In this situation better experimental understanding of the physics phenomena is needed. One aspect of the soft hadronic interactions will be discussed in this work: transfer of the baryon number from the initial to the final state of the interaction. The past experimental knowledge on this process is presented, reasons for its unsatisfactory status are discussed and condition necessary for improvement are outlined: that is experimental apparatus with superior performance over the full range of available interactions: hadron-hadron collision, hadron-nucleus and nucleus-nucleus interactions. A consistent model-independent picture of the baryon number transfer process emerging from the data on the full range of interactions is shown. It offers serious challenge to theory to provide quantitative and detailed explanation of the measurements. (author)

  15. Preliminary Investigation of an Active PLZT Lens

    Science.gov (United States)

    Lightsey, W. D.; Peters, B. R.; Reardon, P. J.; Wong, J. K.

    2001-01-01

    The design, analysis and preliminary testing of a prototype Adjustable Focus Optical Correction Lens (AFOCL) is described. The AFOCL is an active optical component composed of solid state lead lanthanum-modified zirconate titanate (PLZT) ferroelectric ceramic with patterned indium tin oxide (ITO) transparent surface electrodes that modulate the refractive index of the PLZT to function as an electro-optic lens. The AFOCL was developed to perform optical re-alignment and wavefront correction to enhance the performance of Ultra-Lightweight Structures and Space Observatories (ULSSO). The AFOCL has potential application as an active optical component within a larger optical system. As such, information from a wavefront sensor would be processed to provide input to the AFOCL to drive the sensed wavefront to the desired shape and location. While offering variable and rapid focussing capability (controlled wavefront manipulation) similar to liquid crystal based spatial light modulators (SLM), the AFOCL offers some potential advantages because it is a solid-state, stationary, low-mass, rugged, and thin optical element that can produce wavefront quality comparable to the solid refractive lens it replaces. The AFOCL acts as a positive or negative lens by producing a parabolic phase-shift in the PLZT material through the application of a controlled voltage potential across the ITO electrodes. To demonstrate the technology, a 4 mm diameter lens was fabricated to produce 5-waves of optical power operating at 2.051 micrometer wavelength. Optical metrology was performed on the device to measure focal length, optical quality, and efficiency for a variety of test configurations. The data was analyzed and compared to theoretical data available from computer-based models of the AFOCL.

  16. Isolation and culture of adult mouse vestibular nucleus neurons

    Science.gov (United States)

    Him, Aydın; Altuntaş, Serap; Öztürk, Gürkan; Erdoğan, Ender; Cengiz, Nureddin

    2017-12-19

    Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibular nucleus (MVN) from adult mice and describe its morphological and electrophysiological properties.Materials and methods: Vestibular nucleus neurons were mechanically and enzymatically isolated and cultured using a defined medium with known growth factors. Cell survival was measured with propidium iodide, and electrophysiological properties were investigated with current-clamp recording.Results: Vestibular neurons grew neurites in cultures, gaining adult-like morphological properties, and stayed viable for 3 days in culture. Adding bovine calf serum, nerve growth factor, or insulin-like growth factor into the culture medium enhanced neuronal viability. Current-clamp recording of the cultured neurons revealed tonic and phasic-type neurons with similar input resistance, resting membrane potential, action potential amplitude, and duration. Conclusion: Vestibular neurons from adult mice can be cultured, and regenerate axons in a medium containing appropriate growth factors. Culturing adult vestibular neurons provides a new method to study age-related pathologies of the vestibular system.

  17. Wide-field schematic eye models with gradient-index lens.

    Science.gov (United States)

    Goncharov, Alexander V; Dainty, Chris

    2007-08-01

    We propose a wide-field schematic eye model, which provides a more realistic description of the optical system of the eye in relation to its anatomical structure. The wide-field model incorporates a gradient-index (GRIN) lens, which enables it to fulfill properties of two well-known schematic eye models, namely, Navarro's model for off-axis aberrations and Thibos's chromatic on-axis model (the Indiana eye). These two models are based on extensive experimental data, which makes the derived wide-field eye model also consistent with that data. A mathematical method to construct a GRIN lens with its iso-indicial contours following the optical surfaces of given asphericity is presented. The efficiency of the method is demonstrated with three variants related to different age groups. The role of the GRIN structure in relation to the lens paradox is analyzed. The wide-field model with a GRIN lens can be used as a starting design for the eye inverse problem, i.e., reconstructing the optical structure of the eye from off-axis wavefront measurements. Anatomically more accurate age-dependent optical models of the eye could ultimately help an optical designer to improve wide-field retinal imaging.

  18. Gram negative bacteria and contact lens induced acute red eye

    Directory of Open Access Journals (Sweden)

    Sankaridurg Padmaja

    1996-01-01

    Full Text Available Two patients using hydrogel contact lenses on a daily wear schedule slept overnight with the lenses and woke up with a Contact Lens Induced Acute Red Eye (CLARE. The contact lenses recovered aseptically at the time of the event grew significant colonies of Pseudomonas aeruginosa and Aeromonas hydrophila in patient A and Pseudomonas aeruginosa and Serratia liquefaciens from patient B. Similar organisams from the contact lenses were recovered from the lens case and lens care solutions of patient B. In both the patients the condition resolved on discontinuation of lens wear. Patient compliance as a requirement for successful contact lens wear is highlighted with the illustration of these cases.

  19. CUSTOM OPTIMIZATION OF INTRAOCULAR LENS ASPHERICITY

    Science.gov (United States)

    Koch, Douglas D.; Wang, Li

    2007-01-01

    Purpose To investigate the optimal amount of ocular spherical aberration (SA) in an intraocular lens (IOL) to maximize optical quality. Methods In 154 eyes of 94 patients aged 40 to 80 years, implantation of aspheric IOLs was simulated with different amounts of SA to produce residual ocular SA from −0.30 μm to +0.30 μm. Using the VOL-CT program (Sarver & Associates, Carbondale, Illinois), corneal wavefront aberrations up to 6th order were computed from corneal topographic elevation data (Humphrey Atlas, Carl Zeiss Meditec, Inc, Dublin, California). Using the ZernikeTool program (Advanced Medical Optics, Inc, Santa Ana, California), the polychromatic point spread function with Stiles-Crawford effect was calculated for the residual ocular higher-order aberrations (HOAs, 3rd to 6th order, 6-mm pupil), assuming fully corrected 2nd-order aberrations. Five parameters were used to quantify optical image quality, and we determined the residual ocular SA at which the maximal image quality was achieved for each eye. Stepwise multiple regression analysis was performed to assess the predictors for optimal SA of each eye. Results The optimal SA varied widely among eyes. Most eyes had best image quality with low amounts of negative SA. For modulation transfer function volume up to 15 cycles/degree, the amount of optimal SA could be predicted based on other HOAs of the cornea with coefficient of multiple determination (R2) of 79%. Eight Zernike terms significantly contributed to the optimal SA in this model; the order of importance to optimal SA from most to least was: Z60, Z62, Z42, Z53, Z64, Z3−1, Z33, and Z31. For the other 4 measures of visual quality, the coefficients of determination varied from 32% to 63%. Conclusion The amount of ocular SA producing best image quality varied widely among subjects and could be predicted based on corneal HOAs. Selection of an aspheric IOL should be customized according to the full spectrum of corneal HOAs and not 4th-order SA alone

  20. Cell Nucleus-Targeting Zwitterionic Carbon Dots.

    Science.gov (United States)

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-12-22

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation.

  1. Nucleus spectroscopy: extreme masses and deformations

    International Nuclear Information System (INIS)

    Theisen, Ch.

    2009-12-01

    The author proposes a synthesis of research activities performed since 1995 in the field of experimental nuclear physics, and more particularly in the investigation of two nucleus extreme states: deformation on the one hand, heavy and very heavy nuclei on the other hand. After a presentation of the context of investigations on deformation, rotation, and heavy nuclei, he gives an overview of developments regarding instruments (gamma spectrometers, detection of fission fragments, and detection at the focal plane of spectrometers or separators) and analysis techniques. Experiments and results are then reported and discussed, concerning super-deformed states with a high angular moment, spectroscopy of neutron-rich nuclei, very heavy nuclei close to nucleus map borders. He finally draws perspectives for middle and long term studies on the heaviest nuclei

  2. η production in proton-nucleus reactions

    International Nuclear Information System (INIS)

    Cassing, W.; Batko, G.; Vetter, T.; Wolf, G.

    1991-01-01

    The production of η-mesons in proton-nucleus reactions is analysed with respect to primary nucleon-nucleon (NN→NN η ) and secondary pion-nucleon (πN→ηN) production processes on the basis of Hartree-Fock groundstate momentum distributions and free on-shell production processes. The folding model adopted compares well for meson production with more involved simulations based on VUU transport equations. Similar to K + production in proton-nucleus reactions the η-mesons are primarily produced by the πN→ηN channel. However, η-mesons are absorbed in nuclei via excitation of the N * (1535) resonance which leads to strong distortions of the primordial spectra. On the other hand, the experimental mass dependence of the differential cross sections might yield information about the in-medium properties of this resonance. (orig.)

  3. Protein quality control in the nucleus

    DEFF Research Database (Denmark)

    Nielsen, Sofie V.; Poulsen, Esben Guldahl; Rebula, Caio A.

    2014-01-01

    to aggregate, cells have evolved several elaborate quality control systems to deal with these potentially toxic proteins. First, various molecular chaperones will seize the misfolded protein and either attempt to refold the protein or target it for degradation via the ubiquitin-proteasome system...... to be particularly active in protein quality control. Thus, specific ubiquitin-protein ligases located in the nucleus, target not only misfolded nuclear proteins, but also various misfolded cytosolic proteins which are transported to the nucleus prior to their degradation. In comparison, much less is known about...... these mechanisms in mammalian cells. Here we highlight recent advances in our understanding of nuclear protein quality control, in particular regarding substrate recognition and proteasomal degradation....

  4. Alzheimer's disease amyloid-beta links lens and brain pathology in Down syndrome.

    Directory of Open Access Journals (Sweden)

    Juliet A Moncaster

    2010-05-01

    Full Text Available Down syndrome (DS, trisomy 21 is the most common chromosomal disorder and the leading genetic cause of intellectual disability in humans. In DS, triplication of chromosome 21 invariably includes the APP gene (21q21 encoding the Alzheimer's disease (AD amyloid precursor protein (APP. Triplication of the APP gene accelerates APP expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Abeta, early-onset AD neuropathology, and age-dependent cognitive sequelae. The DS phenotype complex also includes distinctive early-onset cerulean cataracts of unknown etiology. Previously, we reported increased Abeta accumulation, co-localizing amyloid pathology, and disease-linked supranuclear cataracts in the ocular lenses of subjects with AD. Here, we investigate the hypothesis that related AD-linked Abeta pathology underlies the distinctive lens phenotype associated with DS. Ophthalmological examinations of DS subjects were correlated with phenotypic, histochemical, and biochemical analyses of lenses obtained from DS, AD, and normal control subjects. Evaluation of DS lenses revealed a characteristic pattern of supranuclear opacification accompanied by accelerated supranuclear Abeta accumulation, co-localizing amyloid pathology, and fiber cell cytoplasmic Abeta aggregates (approximately 5 to 50 nm identical to the lens pathology identified in AD. Peptide sequencing, immunoblot analysis, and ELISA confirmed the identity and increased accumulation of Abeta in DS lenses. Incubation of synthetic Abeta with human lens protein promoted protein aggregation, amyloid formation, and light scattering that recapitulated the molecular pathology and clinical features observed in DS lenses. These results establish the genetic etiology of the distinctive lens phenotype in DS and identify the molecular origin and pathogenic mechanism by which lens pathology is expressed in this common chromosomal disorder. Moreover, these findings confirm increased Abeta

  5. Visual outcomes after lensectomy and iris claw artisan intraocular lens implantation in patients with Marfan syndrome.

    Science.gov (United States)

    Rabie, Hossein Mohammad; Malekifar, Parviz; Javadi, Mohammad Ali; Roshandel, Danial; Esfandiari, Hamed

    2017-08-01

    To review our experience with crystalline lens extraction and iris claw Artisan IOL implantation in patients with lens subluxation secondary to Marfan syndrome. A retrospective analysis of 12 eyes of 9 patients with lens subluxation due to Marfan syndrome who underwent crystalline lens removal and Artisan IOL (Ophtec, Groningen, Netherlands) implantation. A questionnaire of pre- and post-operative data, including demographics, pre- and postoperative comorbidities and complications was completed. Patients were evaluated for visual outcome and occurrence of complications. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), and spherical equivalents (SE) were compared before and after lens extraction and IOL insertion. The mean age of the participants was 30.03 ± 15.02 years, and mean post-operative follow-up time was 44.5 ± 16.4 months. Mean BCVA also showed a significant improvement from 0.5 ± 0.3 at the baseline to 0.2 ± 0.2 post-operatively (P = 0.006). SE changed significantly from -11.38 ± 1.99 preoperatively to -0.45 ± 1.65 post-operatively (P = 0.003). All eyes had the IOL implanted at desired position. Post-operative complications were retinal detachment in one case and IOL dislocation in another patient. No other complication such as ocular hypertension, angle abnormalities, clinical cystoids macular edema, and corneal decompensation was observed during the follow-up period. Artisan IOL implantation after lens extraction appears to be an attractive alternative for optical correction in cases of Marfan syndrome with ectopia lentis. It confers a significant improvement in visual acuity with reasonable risk profile.

  6. Is atomic energy different from a nucleus?

    International Nuclear Information System (INIS)

    Lee, Sun Young

    1995-07-01

    This book describes of two faces of nuclear energy : the secret of a nuclear, the history of nuclear energy : the scientists with a nuclear, the nuclear energy generation : the third disapprobation, a nuclear weapon : Choice of fear, the Korean peninsula and a nuclear and nuclear energy and utilization in peace. It consists of 31 questions and the answers of the questions about nuclear energy and nucleus.

  7. Nuclear alignment following compound nucleus reactions

    International Nuclear Information System (INIS)

    Butler, P.A.; Nolan, P.J.

    1981-01-01

    A procedure for calculating the alignment of a nuclear state populated by a compound nucleus reaction is given and used to investigate how alignment varies for different types of population mechanisms. The calculations are compared to both predictions of Gaussian models for the state population distribution and to experimental data, for a variety of types of nuclear reactions. The treatment of alignment in the analysis of γ-ray angular distribution is discussed. (orig.)

  8. Momentum distribution in the nucleus. II

    International Nuclear Information System (INIS)

    Amado, R.D.; Woloshyn, R.M.

    1977-01-01

    We calculate the single particle momentum distribution n(q) for a one-dimensional model with delta forces. There is a domain of q for which n(q) has an exponential falloff; but, after allowance is made for the nonsaturation in the model, that domain does not grow significantly with particle number. The relation of this result to large momentum scattering from the nucleus and to the Hartree approximation is briefly discussed

  9. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory [Droplet Measurement Technologies, Boulder, CO (United States); Kulkarni, Gourihar [Droplet Measurement Technologies, Boulder, CO (United States)

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  10. Parity violation in the compound nucleus

    International Nuclear Information System (INIS)

    Mitchell, G. E.; Crawford, B. E.; Grossmann, C. A.; Lowie, L. Y.; Bowman, J. D.; Knudson, J.; Penttilae, S.; Seestrom, S. J.; Smith, D. A.; Yen, Yi-Fen; Yuan, V. W.; Delheij, P. P. J.; Haseyama, T.; Masaike, A.; Matsuda, Y.; Postma, H.; Roberson, N. R.; Sharapov, E. I.; Stephenson, S. L.

    1999-01-01

    Measurements have been performed on the helicity dependence of the neutron resonance cross section for many nuclei by our TRIPLE Collaboration. A large number of parity violations are observed. Generic enhancements amplify the signal for symmetry breaking and the stochastic properties of the compound nucleus permit the strength of the symmetry-breaking interaction to be determined without knowledge of the wave functions of individual states. A total of 15 nuclei have been analyzed with this statistical approach. The results are summarized

  11. Measuring the volume of caudate nucleus in healthy Chinese adults of the Han nationality on the high-resolution MRI

    International Nuclear Information System (INIS)

    Ni Mingfei; Chen Nan; Wang Xing; Wu Jianlin; Li Kuncheng; Zhou Xin; Zhou Yan; Chen Lin

    2010-01-01

    Objective: To explore the normal range of the caudate nucleus' volume in Chinese adults of the Han nationality and provide morphological data for the construction of database for Chinese Standard Brain. Methods: This was a clinical multi-center study. One thousand Chinese healthy volunteers (age range =18 to 70) recruited from 16 hospitals were divided into 5 groups, i.e, Group A (age range = 18 to 30), B (age range =31 to 40), C (age range =41 to 50), D (age range =51 to 60), and E (age range =61 to 70). Each group contained 100 males and 100 females. All of the volunteers were scanned by MR using T 1 weighted three-dimensional magnetization prepared rapid acquisition gradient echo sequence. The volume of caudate was measured manually using 3D volume analysis software. The difference of volumes of the caudate between male and female were analyzed by independent sample t-test, and among age groups by ANOVA. Pearson's correlation coefficient was used to characterize the relationship between volumes and age. The differences of measurements between left and right caudate nucleus were analyzed by paired t test. Results: (1) The mean volume of bilateral caudate nucleus in healthy Chinese adults was (10.973± 1.647) cm 3 . The mean volume of the the male's left and right caudate nucleus were (5.656±0.860) and (5.671±0.855) cm 3 respectively,no significant differences were found between the volume of left and right caudate nucleus (t=1.230, P>0.05). The mean volume of the the female's left and right caudate nucleus were (5.287±0.774) and (5.331±0.766) cm 3 respectively, and the right's was larger than the left's with significant differences (t=3.999, P<0.01); (2) Pearson correlation analysis showed a significant negative correlation between the nucleus volume and age (male and female's, left and right) (r=-0.561, -0.568, -0.548, -0.552, P<0.05). Conclusion: With high-resolution MRI and 3D volumetric analytic software (Midob), the volume of the caudate nucleus can be

  12. The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability.

    Science.gov (United States)

    Wolffsohn, James; Hall, Lee; Mroczkowska, Stephanie; Hunt, Olivia A; Bilkhu, Paramdeep; Drew, Tom; Sheppard, Amy

    2015-10-01

    To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Thirty-nine subjects (22.1±3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Lens fit assessments were not different between brands (P>0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12h (P0.05). Movement-on-blink was unaffected by wear-time (F=0.403, P=0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r=-0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P>0.01). Among the lenses tested, objective lens fit changed between 8h and 12h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. Acid phosphatase and lipid peroxidation in human cataractous lens epithelium

    Directory of Open Access Journals (Sweden)

    Vasavada Abhay

    1993-01-01

    Full Text Available The anterior lens epithelial cells undergo a variety of degenerative and proliferative changes during cataract formation. Acid phosphatase is primarily responsible for tissue regeneration and tissue repair. The lipid hydroperoxides that are obtained by lipid peroxidation of polysaturated or unsaturated fatty acids bring about deterioration of biological membranes at cellular and tissue levels. Acid phosphatase and lipid peroxidation activities were studied on the lens epithelial cells of nuclear cataract, posterior subcapsular cataract, mature cataract, and mixed cataract. Of these, mature cataractous lens epithelium showed maximum activity for acid phosphatase (516.83 moles of p-nitrophenol released/g lens epithelium and maximum levels of lipid peroxidation (86.29 O.D./min/g lens epithelium. In contrast, mixed cataractous lens epithelium showed minimum activity of acid phosphatase (222.61 moles of p-nitrophenol released/g lens epithelium and minimum levels of lipid peroxidation (54.23 O.D./min/g lens epithelium. From our study, we correlated the maximum activity of acid phosphatase in mature cataractous lens epithelium with the increased areas of superimposed cells associated with the formation of mature cataract. Likewise, the maximum levels of lipid peroxidation in mature cataractous lens epithelium was correlated with increased permeability of the plasma membrane. Conversely, the minimum levels of lipid peroxidation in mixed cataractous lens epithelium makes us presume that factors other than lipid peroxidation may also account for the formation of mixed type of cataract.

  14. The partial coherence modulation transfer function in testing lithography lens

    Science.gov (United States)

    Huang, Jiun-Woei

    2018-03-01

    Due to the lithography demanding high performance in projection of semiconductor mask to wafer, the lens has to be almost free in spherical and coma aberration, thus, in situ optical testing for diagnosis of lens performance has to be established to verify the performance and to provide the suggesting for further improvement of the lens, before the lens has been build and integrated with light source. The measurement of modulation transfer function of critical dimension (CD) is main performance parameter to evaluate the line width of semiconductor platform fabricating ability for the smallest line width of producing tiny integrated circuits. Although the modulation transfer function (MTF) has been popularly used to evaluation the optical system, but in lithography, the contrast of each line-pair is in one dimension or two dimensions, analytically, while the lens stand along in the test bench integrated with the light source coherent or near coherent for the small dimension near the optical diffraction limit, the MTF is not only contributed by the lens, also by illumination of platform. In the study, the partial coherence modulation transfer function (PCMTF) for testing a lithography lens is suggested by measuring MTF in the high spatial frequency of in situ lithography lens, blended with the illumination of partial and in coherent light source. PCMTF can be one of measurement to evaluate the imperfect lens of lithography lens for further improvement in lens performance.

  15. Study of fragmentation reactions of light nucleus

    International Nuclear Information System (INIS)

    Toneli, David Arruda; Carlson, Brett Vern

    2011-01-01

    Full text: The decay of the compound nucleus is traditionally calculated using a sequential emission model, such as the Weisskopf-Ewing or Hauser-Feshbach ones, in which the compound nucleus decays through a series of residual nuclei by emitting one particle at a time until there is no longer sufficient energy for further emission. In light compound nucleus, however, the excitation energy necessary to fully disintegrate the system is relatively easy to attain. In such cases, decay by simultaneous emission of two or more particles becomes important. A model which takes into account all these decay is the Fermi fragmentation model. Recently, the equivalence between the Fermi fragmentation model and statistical multifragmentation model used to describe the decay for highly excited fragments for reactions of heavy ions was demonstrated. Due the simplicity of the thermodynamic treatment used in the multifragmentation model, we have adapted it to the calculation of Fermi breakup of light nuclei. The ultimate goal of this study is to calculate the distribution of isotopes produced in proton-induced reactions on light nuclei of biological interest, such as C, O e Ca. Although most of these residual nuclei possess extremely short half-lives and thus represent little long-term danger, they tend to be deficient in neutrons and to decay by positron emission, which allows the monitoring of proton radiotherapy by PET (Positron Emission Tomography). (author)

  16. Antinucleon-nucleus elastic and inelastic scattering

    International Nuclear Information System (INIS)

    Dover, C.B.; Millener, D.J.

    1985-01-01

    A general overview of the utility of antinucleon (anti N)-nucleus inelastic scattering studies is presented, emphasizing both the sensitivity of the cross sections to various components of the N anti N transition amplitudes and the prospects for the exploration of some novel aspects of nuclear structure. We start with an examination of the relation between NN and N anti N potentials, focusing on the coherences predicted for the central, spin-orbit and tensor components, and how these may be revealed by measurements of two-body spin observables. We next discuss the role of the nucleus as a spin and isospin filter, and show how, by a judicious choice of final state quantum numbers (natural or unnatural parity states, isospin transfer ΔT = 0 or 1) and momentum transfer q, one can isolate different components of the N anti N transition amplitude. Various models for the N anti N interaction which give reasonable fits to the available two-body data are shown to lead to strikingly different predictions for certain spin-flip nuclear transitions. We suggest several possible directions for future anti N-nucleus inelastic scattering experiments, for instance the study of spin observables which would be accessible with polarized anti N beams, charge exchange reactions, and higher resolution studies of the (anti p, anti p') reaction. We compare the antinucleon and the nucleon as a probe of nuclear modes of excitation. 40 refs., 13 figs

  17. Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

    Science.gov (United States)

    Chhabra, Mahendra

    The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

  18. Segmentation and volumetric analysis of the caudate nucleus in Alzheimer's disease

    International Nuclear Information System (INIS)

    Jiji, Sudevan; Smitha, Karavallil Achuthan; Gupta, Arun Kumar; Pillai, Vellara Pappukutty Mahadevan; Jayasree, Ramapurath S.

    2013-01-01

    Objectives: A quantitative volumetric analysis of caudate nucleus can provide valuable information in early diagnosis and prognosis of patients with Alzheimer's diseases (AD). Purpose of the study is to estimate the volume of segmented caudate nucleus from MR images and to correlate the variation in the segmented volume with respect to the total brain volume. We have also tried to evaluate the caudate nucleus atrophy with the age related atrophy of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) in a group of Alzheimer's disease patients. Methods: 3D fast low angle shot (3D FLASH) brain MR images of 15 AD patients, 15 normal volunteers and 15 patients who had normally diagnosed MR images were included in the study. Brain tissue and caudate nuclei were segmented using the statistical parametric mapping package and a semi-automatic tool, respectively and the volumes were estimated. Volume of segmented caudate nucleus is correlated with respect to the total brain volume. Further, the caudate nucleus atrophy is estimated with the age related atrophy of WM, GM and CSF in a group of AD patients. Results: Significant reduction in the caudate volume of AD patients was observed compared to that of the normal volunteers. Statistical analysis also showed significant variation in the volume of GM and CSF of AD patients. Among the patients who had normal appearing brain, 33% showed significant changes in the caudate volume. We hypothesize that these changes can be considered as an indication of early AD. Conclusion: The method of volumetric analysis of brain structures is simple and effective way of early diagnosis of neurological disorders like Alzheimer's disease. We have illustrated this with the observed changes in the volume of caudate nucleus in a group of patients. A detailed study with more subjects will be useful in correlating these results for early diagnosis of AD

  19. Formation, structure, and evolution of boiling nucleus and interfacial tension between bulk liquid phase and nucleus

    Science.gov (United States)

    Wang, Xiao-Dong; Peng, Xiao-Feng; Tian, Yong; Wang, Bu-Xuan

    2005-05-01

    In this paper, the concept of the molecular free path is introduced to derive a criterion distinguishing active molecules from inactive molecules in liquid phase. A concept of the critical aggregation concentration (CAC) of active molecules is proposed to describe the physical configuration before the formation of a nucleus during vapor-liquid phase transition. All active molecules exist as monomers when the concentration of active molecules is lower than CAC, while the active molecules will generate aggregation once the concentration of the active molecules reaches CAC. However, these aggregates with aggregation number, N, smaller than five can steadily exist in bulk phase. The other excess active molecules can only produce infinite aggregation and form a critical nucleus of vapor-liquid phase transition. Without any outer perturbation the state point of CAC corresponds to the critical superheated or supercooled state. Meanwhile, a model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent of the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provides solid theoretical evidences to clarify the definition of nucleation rate and understand nucleation phenomenon with the insight into the physical nature.

  20. The status of intercellular junctions in established lens epithelial cell lines.

    Science.gov (United States)

    Dave, Alpana; Craig, Jamie E; Sharma, Shiwani

    2012-01-01

    Cataract is the major cause of vision-related disability worldwide. Mutations in the crystallin genes are the most common known cause of inherited congenital cataract. Mutations in the genes associated with intercellular contacts, such as Nance-Horan Syndrome (NHS) and Ephrin type A receptor-2 (EPHA2), are other recognized causes of congenital cataract. The EPHA2 gene has been also associated with age-related cataract, suggesting that intercellular junctions are important in not only lens development, but also in maintaining lens transparency. The purpose of this study was to analyze the expression and localization of the key cell junction and cytoskeletal proteins, and of NHS and EPHA2, in established lens epithelial cell lines to determine their suitability as model epithelial systems for the functional investigation of genes involved in intercellular contacts and implicated in cataract. The expression and subcellular localization of occludin and zona occludens protein-1 (ZO-1), which are associated with tight junctions; E-cadherin, which is associated with adherence junctions; and the cytoskeletal actin were analyzed in monolayers of a human lens epithelial cell line (SRA 01/04) and a mouse lens epithelial cell line (αTN4). In addition, the expression and subcellular localization of the NHS and EPHA2 proteins were analyzed in these cell lines. Protein or mRNA expression was respectively determined by western blotting or reverse transcription-polymerase chain reaction (RT-PCR), and localization was determined by immunofluorescence labeling. Human SRA 01/04 and mouse αTN4 lens epithelial cells expressed either the proteins of interest or their encoding mRNA. Occludin, ZO-1, and NHS proteins localized to the cellular periphery, whereas E-cadherin, actin, and EPHA2 localized in the cytoplasm in these cell lines. The human SRA 01/04 and mouse αTN4 lens epithelial cells express the key junctional proteins. The localization patterns of these proteins suggest that