Waveguide-lattice-based architecture for multichannel optical transformations.

We consider waveguide lattices as the architecture to implement a wide range of multiport transformations. In this architecture, a particular transfer matrix is obtained by setting step-wise profiles of propagation constants experienced by a field evolving in a lattice. To investigate the capabilities of this architecture, we numerically study the implementation of random transfer matrices as well as several notable cases, such as the discrete Fourier transform, the Hadamard, and permutation matrices. We show that waveguide lattice schemes are more compact than their traditional lumped-parameter counterparts, thus the proposed architecture may be beneficial for photonic information processing systems of the future.

Optimal design of error-tolerant reprogrammable multiport interferometers.

Photonic information processing demands programmable multiport interferometers capable of implementing arbitrary transfer matrices, for which planar meshes of error-sensitive Mach-Zehnder interferometers are usually exploited. We propose an alternative design that uses a single-static beam splitter (BS) and a variable phase shift as the building blocks. The design possesses superior resilience to manufacturing errors and losses without extra elements added into the scheme. Namely, the power transmissivities of the static BSs can take arbitrary values in the range from ≈1/2 to ≈4/5. In this Letter, we show that the fraction of transfer matrices non-implementable by the interferometers of our design diminishes rapidly with its size.

Robust Architecture for Programmable Universal Unitaries.

The decomposition of large unitary matrices into smaller ones is important because it provides ways to the realization of classical and quantum information processing schemes. Today, most of the methods use planar meshes of tunable two-channel blocks; however, the schemes turn out to be sensitive to fabrication errors. We study a novel decomposition method based on multichannel blocks. We have shown that the scheme is universal even when the block's transfer matrices are chosen at random, making it virtually insensitive to errors. Moreover, the placement of the variable elements can be arbitrary, so that the scheme is not bound to specific topologies. Our method can be beneficial for large-scale implementations of unitary transformations by techniques, which are not of wide proliferation today or have yet to be developed.

The effects of chronic smoking on lung tissue and the role of alpha lipoic acid.

We investigated the effects of alpha lipoic acid (ALA) on blood and lung tissue exposed chronically to cigarette smoke (CS). Female Sprague-Dawley rats were divided into three groups. Group 1 was the control group (CON): fresh air was supplied twice daily and 0.1 ml physiological saline was given orally for 8 weeks. Group 2 was exposed to CS: 12 cigarettes were smoked daily at two sessions for 1 h and 0.1 ml saline was given orally for 8 weeks. Group 3 (CS + ALA) was exposed to 12 cigarettes daily in two sessions for 1 h and 100 mg/kg/day ALA was given orally for 8 weeks. DNA damage was assessed using comet analysis; oxidative damage was assessed using ischemia-modified albumin (IMA) from blood; and total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) were measured in blood and lung tissue. Histopathological and immunohistochemical evaluation of hypoxia-inducible factor (HIF)-1α, and -2α, caspase-3, vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF2) were conducted using lung tissue. The oxidative markers, TOS, OSI and IMA, and the comet analysis score were increased and the TAS level was decreased in the blood of the CS group compared to the CON group. IMA levels in blood, and TOS and OSI levels in the lung were decreased significantly in the CS + ALA group compared to the CS group. We observed increased septal wall thickness, marked and diffuse inflammatory reaction, emphysema, and necrotic cell debris in bronchial and bronchiolar lumens in the CS group. HIF-1α, HIF-2α, caspase-3 and FGF2 expressions were increased, while VEGF expression decreased in the lung tissues of the CS group compared to the CON group. ALA slightly ameliorated the damage caused by chronic exposure to CS in the lungs, but further investigation is needed to determine its possible protective effects at different dosages.

The impact of electric fields on testis physiopathology, sperm parameters and DNA integrity-The role of resveratrol.

This study investigated the long-term effects of electric fields (EF) which might cause physiopathological or morphological changes in the testis tissues of rats. We assumed that using resveratrol (RES) might reduce harmful effects of the EF. Thirty-two male Wistar Albino rats were randomly divided into four groups with eight animals in each; control, EF, EF + RES and RES. Malondialdehyde (MDA), superoxide dismutase, catalase, glutathione peroxidase and histopathological parameters were evaluated in testis tissue. Epididymal sperm count, motility and DNA damage were studied. Total testosterone, follicle-stimulating hormone, luteinising hormone, estradiol and growth hormone levels were evaluated in the plasma samples. EF caused statistically significant increase in MDA levels, body weight and DNA damage. A significant decrease was detected in sperm count and motility. The histopathological examination of the testes showed the germ cell decrease in the seminiferous epithelium with oedema and vascular congestion in the interstitial tissue. In immunohistochemical examination, the increase in the apoptotic cells number was detected. RES partially ameliorated biochemical, histopathological and immunohistochemical findings in the EF + RES group. These findings clearly demonstrated that EF can cause damage in rat testis. RES can ameliorate the damage caused by EF.

Laser-written polarizing directional coupler with reduced interaction length.

Integrated optical waveguides, manufactured with femtosecond laser writing (FSLW) technology, enable precise control and manipulation of light in complicated photonic chips. However, due to the intrinsically low anisotropy of FSLW waveguides, polarizing integrated devices have had a relatively large footprint. In this Letter, we demonstrate an approach based on stress-induced anisotropy, allowing us to decrease the size of polarizing directional couplers down to 3.7 mm, almost an order of magnitude shorter than previously reported. The measured extinction ratios at the wavelength of 808 nm are 16 dB and 20 dB for the horizontal and vertical polarizations, respectively. We provide a possible theoretical model for the observed effects.

The impact of sleep deprivation on hippocampal-mediated learning and memory in rats.

BACKGROUND: To examine the impact of different types of sleep deprivation on hippocampal-mediated learning and memory in rats. METHODS: Forty-eight Sprague-Dawley male rats were randomly assigned to 1 of 4 equal-size groups: (1) 12 hours of sleep per day (control). (2) total sleep deprivation (TSD), (3) rapid eye movement (REM) deprivation (RD), and (4) sleep restricted to 4 hours per day (SR). All rats were subjected to swimming training in the Morris water maze (MWM). At the end of the experiments, the rats were decapitated, and hippocampus tissue was analyzed for several neurotransmitters and receptors. RESULTS: The time spent at the target quadrant increased from 20.2 to 30.0 seconds in the control group on the third day of the experiment, whereas corresponding values increased from 20.2 to 21.8 seconds in the TSD group, 22.1 to 25.4 seconds in the RD group, and 21.2 to 32.0 sec in the SR group (p = 0.026). On the seventh day of the experiment, the values decreased to 25.0 seconds in controls, 22.5 in the RD group, and 23.6 in the SR group (p = 0.045). The TSD group demonstrated significant decreases in glutamate and serotonin levels compared with the control group. There was a significant increase in 5-HT2a receptor expression in all intervention groups compared with the controls. CONCLUSIONS: Our results of glutamate levels and 5-HT2a receptor expression in the hippocampus seem to be primarily involved in sleep and memory regulation (Tab. 2, Fig. 4, Ref. 59).

The effects of electromagnetic radiation (2450 MHz wireless devices) on the heart and blood tissue: role of melatonin.

OBJECTIVE: This study was designed to investigate the effects of 2450 MHz EMR on the heart and blood in rat and possible ameliorating effects of melatonin. MATERIAL AND METHOD: Thirty-two female Wistar Albino rats were randomly grouped (by eight in each group) as follows:  Group I: cage-control group (dimethysulfoxide (DMSO), 10mg/kg/day i.p. without stress and EMR. Group II: sham-control rats stayed in restrainer without EMR and DMSO (10mg/kg/day i.p.). Group III: rats exposed to 2450 MHz EMR. Group IV: treated group rats exposed to 2450 MHz EMR+melatonin (MLT) (10mg/kg/day i.p.). RESULTS: In the blood tissue, there was no significant difference between the groups in respect of erythrocytes GSH, GSH-Px activity, plasma LP level and vitamin A concentration (p > 0.05). However, in the Group IV, erythrocytes' LP levels (p < 0.05) were observed to be significantly decreased while plasma vitamin C, and vitamin E concentrations (p < 0.05) were found to be increased when compared to Group III. In the heart tissues, MDA and NO levels significantly increased in group III compared with groups I and II (p < 0.05). Contrary to these oxidant levels, CAT and SOD enzyme activities decreased significantly in group III compared with groups I and II (p 0.05). Besides, MLT treatment lowered the MDA and NO levels compared with group III. DISCUSSION: In conclusion, these results demonstrated that contrary to its effect on the heart, the wireless (2450 MHz) devices cause slight oxidative-antioxidative changes in the blood of rats, and a moderate melatonin supplementation may play an important role in the antioxidant system (plasma vitamin C and vitamin E). However, further investigations are required to clarify the mechanism of action of the applied 2450 MHz EMR exposure (Tab. 3, Fig. 1, Ref. 49).

The impact of high fructose on cardiovascular system: Role of α-lipoic acid.

The aim of this study was to evaluate the role of α-lipoic acid (α-LA) on oxidative damage and inflammation that occur in endothelium of aorta and heart while constant consumption of high-fructose corn syrup (HFCS). The rats were randomly divided into three groups with each group containing eight rats. The groups include HFCS, HFCS + α-LA treatment, and control. HFCS was given to the rats at a ratio of 30% of F30 corn syrup in drinking water for 10 weeks. α-LA treatment was given to the rats at a dose of 100 mg/kg/day orally for the last 6 weeks. At the end of the experiment, the rats were killed by cervical dislocation. The blood samples were collected for biochemical studies, and the aortic and cardiac tissues were collected for evaluation of oxidant-antioxidant system, tissue bath, and pathological examination. HFCS had increased the levels of malondialdehyde, creatine kinase MB, lactate dehydrogenase, and uric acid and showed significant structural changes in the heart of the rats by histopathology. Those changes were improved by α-LA treatment as it was found in this treatment group. Immunohistochemical expressions of tumor necrosis factor α and inducible nitric oxide synthase were increased in HFCS group, and these receptor levels were decreased by α-LA treatment. All the tissue bath studies supported these findings. Chronic consumption of HFCS caused several problems like cardiac and endothelial injury of aorta by hyperuricemia and induced oxidative stress and inflammation. α-LA treatment reduced uric acid levels, oxidative stress, and corrected vascular responses. α-LA can be added to cardiac drugs due to its cardiovascular protective effects against the cardiovascular diseases.

Impact of L-carnitine and Selenium Treatment on Testicular Apoptosis in Rats Exposed to 2.45 GHz Microwave Energy.

OBJECTIVE: It has been suggested that electromagnetic radiation (EMR) by wireless devices (2.45 GHz) induces testicular apoptosis. We investigated if supplemental selenium (Se) and L-carnitine may reduce this adverse effect. MATERIAL: Twelve-week old male Wistar albino rats were used in this study. Twenty-four rats were equally divided into four groups which were named as: sham group, EMR-only, EMR+L-carnitine (1.5 mg L-carnitine/kg/day) and EMR+Se (1.5 mg Se/kg/-every other day). RESULTS: The level of Bcl-2, Bax, caspase-3 and -8 were compared and a significant difference was found between the sham and EMR-only groups (p < 0.05), and Bcl-2, Bax, caspase-3 and -8 expressions increased in the EMR-only group. The level of Bcl-2, Bax, tumour necrosis factor-alpha (TNF-α), caspase-3 and -8 were compared and a significant difference was found between the sham and EMR+L-carnitine groups (p < 0.05) and Bcl-2, Bax, TNF-α, caspase-3 and -8 expressions increased in the EMR+L-carnitine group. The level of Bcl-2, Bax, TNF-α, caspase-3 and -8 were compared and a significant difference was found between the sham and EMR+Se groups (p < 0.05) and Bcl-2, Bax, TNF-α, caspase-3 and -8 expressions increased in the EMR+Se group. When the expression of caspase-8 was compared, a significant difference was found between the EMR-only and EMR+Se groups (p < 0.05). Caspase-8 expression decreased in EMR+Se group compared with EMR-only group. CONCLUSION: Electromagnetic radiation exposure resulted in testicular apoptosis in rats, mainly by the intrinsic pathways by down-regulated expression of caspase-8. Reduction in the activation of the intrinsic pathway of apoptosis was found higher with selenium administration compared with L-carnitine administration.

Effects of ionizing radiation on respiratory function tests and blood parameters in radiology staff.

AIM: To evaluate pulmonary function tests and blood parameters and their relationship with sociodemographic data for radiology staff continuously exposed to ionizing radiation. SUBJECTS AND METHODS: Thirty-eight personnel from Suleyman Demirel University Training and Research Hospital, Radiology Unit, were included in this study. Sociodemographic data were evaluated by a questionnare that was developed by the researchers. Height and weight measurements were performed with a standard scale and meter. Routine blood parameters and spirometric lung function measurements of the cases were recorded. Statistical significances were determined by independent t-test, analysis of variance (ANOVA), bivariate correlation and Kruskal-Wallis tests using SPSS 18.0. RESULTS: The mean age was 32.42 ± 5.5 years; 19 patients (50%) were male and 19 patients (50%) were female. Body mass index (BMI) was calculated as 25.68 ± 0.47 for men and 24.58 ± 1.13 for women. Forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1), peak expiratory flow (PEF) and maximum mid-expiratory flow (FEF25-75) showed negatively statistically significant differences between gender (p < 0.01). In addition, FEV1 and FEF25-75 also demonstrated statistically negatively significant difference with the type of task (p < 0.05). A statistically significant negative difference was found between FEF25-75 value and time to start smoking (p < 0.05). Among FVC, FEV1, PEF and FEF25-75 values and alcohol usage, statistically significant positive difference was detected (p < 0.05). Statistically significant positive difference was found among FVC, PEF and FEF25-75 values and sports activity (p < 0.05). According to BMI groups, statistically significant positive difference with FVC, FEV1 and PEF values were found (p < 0.05). Statistically significant correlations were found among FVC value and haemoglobin level (Hgb), haematocrit level (Hct) and mean corpuscular volume (MCV), among FEV1 value and Hgb, MCV, among PEF value and red blood cell count (RBC), Hgb, Hct, MCV, red cell distribution width (RDW), and between FEF25-75 value and MCV. CONCLUSION: Although respiratory functions of radiology staff are affected by many factors, continuous exposure to ionizing radiation is one of the important parameters. Radiology staff should be informed about factors that negatively affect the respiratory functions.

Effects of ionizing radiation on respiratory function tests and blood parameters in radiology staff / Efectos de las Radiaciones ionizantes en las pruebas de función respiratoria y los parámetros de la sangre del personal de radiología

AIM: To evaluate pulmonary function tests and blood parameters and their relationship with sociodemographic data for radiology staff continuously exposed to ionizing radiation. SUBJECTS AND METHOD: Thirty-eight personnel from Suleyman Demirel University Training and Research Hospital, Radiology Unit, were included in this study. Sociodemographic data were evaluated by a questionnare that was developed by the researchers. Height and weight measurements were performed with a standard scale and meter. Routine blood parameters and spirometric lung function measurements of the cases were recorded. Statistical significances were determined by independent t-test, analysis of variance (ANOVA), bivariate correlation and Kruskal-Wallis tests using SPSS 18.0. RESULTS: The mean age was 32.42 ± 5.5 years; 19 patients (50%) were male and 19 patients (50%) were female. Body mass index (BMI) was calculated as 25.68 ± 0.47 for men and 24.58 ± 1.13 for women. Forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1), peak expiratory flow (PEF) and maximum mid-expiratory flow (FEF25-75) showed statistically significant differences between gender (p < 0.01). In addition, FEV1 and FEF25-75 also demonstrated statistically negatively significant difference with the type of task (p < 0.05). A statistically significant negative difference was found between FEF25-75 value and time to start smoking (p < 0.05). Among FVC, FEV1, PEF and FEF25-75 values and alcohol usage, statistically significant positive difference was detected (p < 0.05). Statistically significant positive difference was found among FVC, PEF and FEF25-75 values and sports activity (p < 0.05). According to BMI groups, statistically significant positive difference with FVC, FEV1 and PEF values were found (p < 0.05). Statistically significant correlations were found among FVC value and haemoglobin level (Hgb), haematocrit level (Hct) and mean corpuscular volume (MCV), among FEV1 value and Hgb, MCV, among PEF value and red blood cell count (RBC), Hgb, Hct, MCV, red cell distribution width (RDW), and between FEF25-75 value and MCV. CONCLUSION: Although respiratory functions of radiology staff are affected by many factors, continuous exposure to ionizing radiation is one of the important parameters. Radiology staff should be informed about factors that negatively affect the respiratory functions.

OBJETIVO: Evaluar las pruebas de función pulmonar y parámetros de sangre y su relación con los datos sociodemográficos para el personal de radiología continuamente expuesto a la radiación ionizante. SUJETOS Y MÉTODO: Este estudio incluyó treinta y ocho miembros del personal de la Unidad de Radiología del Hospital de Docencia e Investigación de la Universidad Suleyman Demirel. Los datos sociode-mográficos se evaluaron mediante un formulario que fue desarrollado por los investigadores. Se realizaron mediciones de la altura y el peso con un metro y una escala estándar. Se registraron los datos de rutina sobre los parámetros de sangre y las mediciones de la función pulmonar espirométrica de los casos. La respectiva importancia estadística fue determinada mediante la prueba t independiente, análisis de varianza (ANOVA), correlación bivariada y pruebas de Kruskal-Wallis utilizando SPSS 18.0. RESULTADOS: La edad promedio fue de 32.42 ± 5,5 años; 19 pacientes (50%) eran varones y 19 pacientes (50%) eran mujeres. El índice de masa corporal (IMC) se calculó como 25.68 ± 0.47 para los hombres y 24.58 ± 1.13 para las mujeres. La capacidad vital forzada (CVF), el volumen espiratorio forzado en el primer segundo (VEF1), el flujo espiratorio máximo (FEM), y los valores del flujo espiratorio medio máximo (FEMM25-75) mostraron diferencias negativas estadísticamente significativas entre géneros (p < 0.01). Además, el VEF1 y el FEMM25-75 también mostraron diferencias negativas estadísticamente significativas en relación con el tipo de la tarea (p < 0.05). Se halló una diferencia negativa estadísticamente significativa entre el valor de FEMM25-75 y el tiempo del inicio del hábito de fumar (p < 0.05). Se detectó una diferencia positiva estadísticamente significativa entre los valores de CVF, VEF1, FEM y FEMM25-75, y el hábito de consumir alcohol (p < 0.05). Se detectó una diferencia positiva estadísticamente significativa entre los valores de CVF, FEM y FEMM25-75, y las actividades de deporte (p < 0.05). Según los grupos de IMC, se halló una diferencia positiva estadísticamente significativa positiva entre los valores de CVF, VEF1, y los valores de FEM (p < 0.05). Se hallaron correlaciones estadísticamente significativas entre el valor de CVF y el nivel de la hemoglobina (Hgb), el nivel de hematocrito (Hct) y el volumen corpuscular medio (VCM); entre el valor de VEF1 y Hgb, VCM; entre el valor de FEM, y el conteo de glóbulos rojos (CGR), Hgb, Hct, VCM, y la distribución de los glóbulos rojos;y entre el valor de FEMM25-75 y VCM. CONCLUSIÓN: Aunque las funciones respiratorias del personal de radiología son afectadas por muchos factores, la exposición continua a la radiación ionizante es uno de los parámetros importantes. El personal de radiología debe ser informado acerca de los factores prevenibles que afectan negativamente las funciones respiratorias.

Testicular apoptosis and histopathological changes induced by a 2.45 GHz electromagnetic field.

There is a growing public concern about the potential human health hazard caused by exposure to electromagnetic radiation (EMR). The objective of this study is to investigate the effects of 2450 mhz electromagnetic field on apoptosis and histopathological changes on rat testis tissue. Twelve-week-old male Wistar Albino rats were used in this study. Eighteen rats equally divided into three different groups which were named group I, II and III. Cage control (group I), sham control (group II) and 2.45 GHz EMR (group III) groups were formed. Group III were exposed to 2.45 GHz EMR, at 3.21 W/kg specific absorption rate for 60 minutes/ day for 28 days. There was no difference among the groups for the diameter of the seminiferous tubules, pyknotic, karyolectic and karyotic cells. However, the number of Leydig cells of testis tissue of the rats in group III was significantly reduced comparing with the group I (p < 0.05). Estimation of spermatogenesis using the Johnsen testicular biopsy score revealed that the difference between groups is statistically significant. The level of TNF-α, Caspase-3 and Bcl-2 were compared, and no significant difference was found between the groups. When Bax apoptosis genes and Caspase-8 apoptosis enzyme were compared, there were significant differences between the groups (p < 0.05). Electromagnetic field affects spermatogenesis and causes to apoptosis due to the heat and other stress-related events in testis tissue.