53 research outputs found

    New high performance realizations for current controlled conveyor (CCCII)

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    In this paper two new realizations, one CMOS and one bipolar, for current-controlled conveyor (CCCII) are proposed. The proposed circuits provide a good linearity, very high input impedance at port-y, high output impedance at port-z and good output/input current gain. SPICE simulation results using TUBITAK 3 CMOS process model are included to verify the expected values

    The antioxidant effects of taurine, melatonin and N-acetylcysteine in cadmium-induced lung injury

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    Amaç: Antioksidan özelliği bilinen taurin, melatonin ve N-asetilsisteinin (NAC) kadmiyum klorüre (CdCl2) bağlı olarak gelişen akciğer hasarını önlemedeki ve oluşmuş hasarı tedavi etmedeki etkinlikleri karşılaştırıldı. Çalışma Planı: Çalışmamızda 90 adet erkek Sprague-Dawley cinsi sıçan dokuz gruba ayrıldı. Üç ay süreyle grup 1'e içme suyu, grup 2'ye 200 ppm CdCl2, grup 3'e 200 ppm CdCl2 ve %1 taurin, grup 4'e 200 ppm CdCl2 ve %0.02 melatonin, grup 5'e 200 ppm CdCl2 ve %0.5 NAC içme sularına katıldı. Grup 6, 7, 8 ve 9'un içme sularına üç ay süreyle 200 ppm CdCl2 katıldıktan sonra; yedi gün süreyle 6. gruba içme suyu, 7. gruba %4 taurin, 8. gruba %0.08 melatonin ve 9. gruba %2 NAC içme sularına katılarak verildi. Bulgular: Koruyucu amaçla verilen melatonin ve NAC'nin azalmış glutatyon düzeyini artırdığı, hem koruyucu hem de tedavi amaçlı verilen üç ajanın da artmış olan lipit peroksidasyonun son ürünlerinden biri olan malondialdehit düzeylerini azalttığı görüldü. Sonuç: Taurin, melatonin ve NAC CdCl2'e bağlı olarak gelişen akciğer hasarına karşı hem koruyucu hem de tedavi edici rol oynamaktadır.Objectives: The potential protective and therapeutic effects of taurine, melatonin and N-acetylcysteine (NAC), which are recognized as antioxidant agents, in cadmium chloride (CdCl2)-induced lung injury were compared. Study Design: Ninety male Sprague-Dawley rats were divided into 9 groups. During the 3 months treatment period, group 1 received drinking water, group 2 200 ppm CdCl2, group 3 200 ppm CdCl2 and 1% taurine, to, group 4, 200 ppm CdCl2 and 0.02% melatonin, and group 5 received 200 ppm CdCl2 and 0.5% NAC all added into drinking water in each group. After, groups 6, 7, 8 and 9 received 200 ppm CdCl2 in their drinking water for 3 months, group 6 was given drinking water, group 7, 4% taurine, group 8, 0.08% melatonin and group 9, 2% NAC, each for 7 days. Results: Melatonin and NAC which were given for protective purposes, increased the decreased glutathione levels. The 3 substances that were administered for both protective and therapeutic purposes, decreased the increased malondialdehyde levels, one of the end products of lipid peroxidation. Conclusion: Taurine, melatonin and NAC play protective and therapeutic roles in CdCl2 induced lung injury

    Prevalence of Geographic Atrophy in Advanced Age-Related Macular Degeneration (AMD) in Daily Practice

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    Purpose: To investigate the prevalence of geographic atrophy (GA) in advanced age-related macular degeneration (AMD) and the proportion of eyes that would meet the indication criteria for treatment with the first intravitreal anti-C3 agent (pegcetacoplan). Methods: This retrospective cross-sectional study included all AMD patients who visited the Macular-Retina-Centre Oberkassel in 2021. Eyes were classified according to AMD stages. Eyes with GA were divided into two groups regarding foveal involvement. Baseline factors were compared between eyes with foveal GA (FGA) and eyes with non-foveal GA (NFGA) to identify predictive factors for foveal involvement. Results: A total of 2033 eyes from 1027 patients were included. AMD stage was early in 296 (14.5%) cases, intermediate in 368 (18.1%) cases, and advanced in 1249 (61.4%) cases. A total of 1204 (60%) eyes had GA [932 (77%) FGA and 272 (23%) NFGA], while 125 eyes (27.4% from eyes with advanced dry AMD) met the indication criteria for treatment with intravitreal pegcetacoplan. The proportion of eyes with neovascular AMD was significantly higher in the FGA group compared to the NFGA group [598 (64.2%) vs. 152 (55.8%), p = 0.01]. Conclusions: At least a quarter of eyes with advanced AMD would be suitable for the upcoming intravitreal pegcetacoplan therapy. Foveal involvement of GA in advanced AMD seems to be more likely in neovascular AMD than in dry AMD

    A Rapid and Convenient Procedure to Evaluate Optical Performance of Intraocular Lenses

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    A new portable lens scanner was developed and tested for measuring focal lengths and relative contrast transfer of mono- and multifocal intraocular lenses (IOLs). A photograph of a natural scene was imaged in white light through an IOL in a water-filled cuvette, with their +21D base power largely neutralized by a −20D trial lens, using a USB monochrome video camera that could be focused via a laptop-controlled stepping motor from −8.5 to + 8.0D. The output of 10000 ON-OFF antagonistic “receptive fields” measuring the video image with adjustable diameter was continuously recorded by custom written software to quantify focus and relative contrast. Six monofocal and four multifocal IOLs, as well as two radial refractive gradient (RRG) lenses were measured. After calibration with trial lenses the optical powers and relative contrast transfer of mono- and multifocal IOLs were readily measured. Refractive power profiles measured in RRG lenses closely matched data obtained from the manufacturer. The lens scanner uses a rapidly operating procedure, is portable and can be used to verify positions of the focal planes of mono- and multifocal IOLs in less than 3 s

    New CMOS configurations for current-controlled conveyors (CCCIIs)

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    In this paper two new CMOS configurations for current-controlled conveyor (CCCII) are proposed. The proposed circuits provide good linearity, very high input impedance at port-y, high output impedance at port Z and good input/output current gain. SPICE simulation results using TUBITAK 3 μ CMOS process model are included to verify the expected values

    Detection of Far Infrared Radiation using Glow Discharge Detectors GDDs

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    The plasma medium which is created inside the GDD enables us to detect a wide wavelength range of differential or modulated EM signals impinging on them [1-2]. The interaction between the plasma and various frequency EM waves are still being investigated and in the terahertz range the interaction mechanism is still not well understood [1]. To understand the interaction better commercially available GDDs were studied using both time-domain and continuous wave mm wave/THz measurement systems. Using a 113GHz Schottky diode multiplied source the detection behaviour of the detector was investigated while the interaction of the GDD structure with the THz field was investigated between 100-1000GHz. The GDD response is similar to other commercially available room temperature mm wave/THz detectors and performs at a fraction of their cost. Using lock-in detection techniques the response was characterized at modulation frequencies up to 100 kHz. Furthermore the orientation of the electrode structure was sensitive to the polarization of the incident field. The polarization sensitive behaviour indicates a strong coupling between the incident and native field in the plasma. These effects were investigated by transmitting a broadband THz pulse through the structure for when the device was on and off. Within the constraints on the maximum modulation frequency of the THz transmitter antenna, certain THz frequencies are attenuated suggesting the electrode structure of the GDD can play a role in the detection. Future work will entail understanding the interaction by using numerical simulations modelling of a similar geometric structure with a glow discharge under modulated EM wave illumination

    From the First Episode to Recurrences: The Role of Automatic Thoughts and Dysfunctional Attitudes in Major Depressive Disorder

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    Negative automatic thoughts (NAT) and dysfunctional attitudes (DA) are causal elements in the onset and maintenance of depression. It has previously been reported that NATs become more prevalent during depressive episodes. DAs are known to be influencing both the first and the recurrent depressive episodes. This study aims to focus on the differences observed in the depressive cognitions of the first episode and the recurrently depressed patients, and to investigate if negative cognitions may be predictive of a depressive recurrence. The hypothesis of the study is that automatic thoughts and dysfunctional attitudes of adult depressed patients might be predictive of a recurrence. For the present study, 100 first episode depressed, 100 recurrent episode depressed, and 100 healthy control subjects were recruited. All patients were diagnosed by a structured clinical interview according to the DSM-IV-TR criteria, and any patients with a comorbid diagnosis were excluded. The participants were asked to complete the Beck Depression Inventory (BDI), the Automatic Thoughts Questionnaire (ATQ), and the Dysfunctional Attitude Scale (DAS). The groups were compared with each other on the scores of their cognitive scales, and hierarchical regression analyses were undertaken to predict the number of recurrences. The ATQ and DAS scores differentiated all three groups, and the highest scores were obtained by the recurrently depressed patients. The hierarchical regression analyses for the prediction of the number of recurrences showed that the highest partial correlation was for the perfectionistic attitude. Correlational analyses revealed that the highest correlation was between the number of recurrences, and the perfectionistic attitude. Our results have indicated that the first episode depressed patients differ from the recurrently depressed patients in terms of their ATQ and DAS scores, and that the number of recurrences may best be predicted by the scores related to perfectionistic attitudes. These results suggest that some cognitions should selectively be addressed in psychotherapy for the prevention of depressive recurrences
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