A distance-independent basal area growth model for oriental spruce (Picea orientalis (l.) Link) growing in mixture with oriental beech (Fagus orientalis Lipsky) in the Artvin region, North-East Turkey

In this study, we developed an individual tree basal area growth model for oriental spruce (Picea orientalis (L.) Link) growing in mixture with oriental beech (Fagus orientalis Lipsky) in the Artvin, Turkey. In our modeling approach, the basal area growth variables were divided into 4 main groups, which included size, competition, site and mixture. The parameters of these variables were biologically consistent with general growth trends of forest growth models and we found them each to be statistically significant at the probability level of 0.05. Our model explained 62.4% of the basal area growth variation of oriental spruce with a standard error of 0.836 cm2. Furthermore, we found that the absolute and relative (%) biases and the root mean square error (RMSE and RMSE%) of the 5 year basal area growth of oriental spruce were 0.00823 cm2, 0.1353%, 0.8234 cm2, 33.39% respectively. We evaluated this model by plotting the biases with respect to considerable regressor variables. These graphical analyses of the model biases showed no meaningful and evident trend of bias values along with these independent variables. Our model provides a clear frame of reference for understanding about the individual tree basal area growth patterns of for oriental spruce growing in mixture with oriental beech. This model further shows that the parameter of the mixture proportion (BP) for oriental beech trees in the mixture model component was positive, indicating that basal area growth of spruce increases as the proportion of beech in the forest mixture goes up if other variables remain constant. This positive effect of admixture may be due to the facilitation process occurring in oriental spruce stands mixed with beech trees. The facilitation pattern of beech trees in mixing spruce stands suggests that poor or degraded forest sites may be improved by mixing beech trees for forest areas in this region

Quercetin protects the retina by reducing apoptosis due to ischemia-reperfusion injury in a rat model

Purpose: This study aimed to investigate the effect of quercetin on apoptotic cell death induced by ischemia-reperfusion (I/R) injury in the rat retina. Methods: Twenty-four rats were divided into four equal groups: control, ischemic, solvent, and quercetin. I/R injury was achieved by elevating the intraocular pressure above the perfusion pressure. Intraperitoneal injections of 20 mg/kg of quercetin and dimethyl sulfoxide (DMSO) were performed in the quercetin and solvent groups, respectively, immediately prior to I/R injury, and the researchers allowed for the retinas to be reperfused. Forty-eight hours after injury, the thicknesses of the retinal ganglion cell layer (RGCL), inner nuclear layer (INL), inner plexiform layer (IPL), outer plexiform layer (OPL), and outer nuclear layer (ONL) were measured in all groups. Moreover, the numbers of terminal deoxynucleotidyl transferase dUTP nick-end-labeled [TUNEL (+)] cells and caspase-3 (+) cells in both INL and ONL were evaluated in all groups. Results: The administration of quercetin was found to reduce the thinning of all retinal layers. The mean thickness of INL in the quercetin and ischemic groups was 21 ± 5.6 µm and 16 ± 6.4 µm, respectively (P<0.05). Similarly, the mean thickness of ONL in the quercetin and ischemic groups was 50 ± 12.8 µm and 40 ± 8.7 µm, respectively (P<0.05). The antiapoptotic effect of quercetin in terms of reducing the numbers of both TUNEL (+) cells and caspase-3 (+) cells was significant in INL. The mean number of TUNEL (+) cells in INL in the ischemic and quercetin groups was 476.8 ± 45.6/mm2 and 238.72 ± 251/mm2, respectively (P<0.005). The mean number of caspase-3 (+) cells in INL of ischemic and quercetin groups was 633.6 ± 38.7/mm2 and 342.4 ± 36.1/mm2, respectively (P<0.001). Conclusion: The use of quercetin may be beneficial in the treatment of retinal I/R injury because of its antiapoptotic effect on the retinal layers, particularly in INL

Protective Effect of Hesperetin and Naringenin against Apoptosis in Ischemia/Reperfusion-Induced Retinal Injury in Rats

Purpose. Hesperetin and naringenin are naturally common flavonoids reported to have antioxidative effects. This study was performed to investigate whether either hesperetin or naringenin has a protective effect against apoptosis on retinal ischemia/reperfusion (I/R) injury. Methods. Retinal I/R was induced by increasing the intraocular pressure to 150 mmHg for 60 minutes. Thirty-three male Wistar albino rats were randomised into 5 groups named control, I/R + sham, I/R + solvent (DMSO), I/R + hesperetin, and I/R + naringenin. Animals were given either hesperetin, naringenin, or the solvent intraperitoneally immediately following reperfusion. Thickness of retinal layers and retinal cell apoptosis were detected by histological analysis, tunel assay, and immunohistochemistry assay. Results. Hesperetin and naringenin attenuated the I/R-induced apoptosis of retinal cells in the inner and outer nuclear cells of the rat retina. Retinal layer thickness of the naringenin treatment group was significantly thicker than that of the hesperetin, sham, and solvent groups (P<0.05). Conclusions. Hesperetin and naringenin can prevent harmful effects induced by I/R injury in the rat retina by inhibiting apoptosis of retinal cells, which suggests that those flavanones have a therapeutic potential for the protection of ocular ischemic diseases

Comparison of mechanical and ultrasonic agitation methods for mono c-Si texturing

Texturing of a mono crystalline Si wafer aims to create light trapping structures to reduce the reflection losses. Being a cheap and efficient process, alkaline texturing of Si wafers is commonly used in all industrial mono crystalline solar cell production lines. However, standard process with potassium hydroxide ( KOH)-based solutions with isopropyl alcohol ( IPA) addition suffers from instability, high material consumption, and nonuniformities in the shape and the distribution of the pyramid structures formed on the Si surface. In this work, we studied the effect of ultrasonic agitation ( UA) during the etching process on the structural, optical, and electrical properties of mono crystalline Si solar cell as a function of process parameters. We have shown that UA improves optical and electrical performance of the cells by forming uniform pyramid structures. In addition, it also helps to lower the material consumption and Si removal from the surface by enabling less process time and temperature. Ultrasonic agitation of the etching solution proves to be a good modification of the wet process steps for the mono crystalline silicon solar cell technology. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Photoelectrocatalytic Degradation of Paraquat by Pt Loaded TiO2 Nanotubes on Ti Anodes

Nanotube structured TiO2 on Ti surface were prepared in ethylene glycol (Ti/TiO2NTEG) medium by anodic oxidation method with different times and then the plates were calcinated at different temperatures. Non-nanotube structured Ti/TiO2, prepared by thermal oxidation method, and nanotube structured TiO2 on Ti plate in hydrogen fluoride solution were also prepared for comparison. Pt loaded Ti/TiO2NTEG photoanodes were also prepared by cyclic voltammetry method with different cycles and the optimum loaded Pt amount was determined. Photoanodes were characterized by using X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy-Dispersive X-ray Analysis (SEM-EDX), and photocurrent methods. XRD analyses proved that almost all TiO2 is in anatase phase. SEM analyses show that nanotubes and Pt nanoparticles on nanotube surface are dispersed quite homogeneously. The longest nanotubes were obtained in the ethylene glycol medium and the nanotube length increased by increasing applied anodic oxidation time. In addition, a linear correlation between nanotube length and XRD peak intensity was found. Moreover, SEM-EDX and XRD analyses evidence that Pt nanoparticles on nanotube surface are metallic and in cubic structure. Photoelectrocatalytic degradation of paraquat was performed using the prepared photoanodes. Moreover, electrocatalytic and photocatalytic degradations of paraquat were also investigated for comparison, however lower activities were observed. These results evidence that the photoanodes show a significant synergy for photoelectrocatalytic activity

Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly

Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury

Near-unity haze by aluminum induced glass texturing: structural evolution of Al/glass interface and its impact on texturing

Aluminum induced texturing (AIT) is an effective method to enhance light trapping in thin film solar cells through texturing the surface of the glass substrate. The topography of the textured glass is closely related to the processes that occur at the Al/glass interface during thermal annealing, which is commonly carried out at temperatures above 500 degrees C. The annealing temperature significantly influences the redox reaction between Al and SiO2, and thus the resultant surface texture. In this study, the effect of annealing temperature on the AIT process is investigated in order to elucidate on the evolution of the metallic Al over-layer into the final Al2O3 - c-Si mixture. The structural and compositional changes at the Al/glass interface are compared for samples annealed at varying temperatures. The influence of annealing temperature on the final morphology of the glass surface is also discussed, along with its optical transmittance. (C) 2017 Optical Society of Americ