Quantification of nickel, cobalt, and manganese concentration using ultraviolet-visible spectroscopy.

Ultraviolet-visible spectroscopy is one of the most effective, inexpensive, flexible, and simplest analytical techniques to measure species concentration in the liquid phase. It has a wide range of applications such as wastewater treatment, dye degradation, colloidal nanoparticle characterization. It is used in almost every spectroscopy laboratory for routine analysis or research. In the present study, a feasibility study was carried out to find the application of UV-Vis spectroscopy for onsite measurement of nickel, cobalt, manganese, and lithium as a replacement for the conventional method to measure the concentrations of these elements in battery and other applicable industries. Samples with different concentrations of individual elements and composites were prepared and analyzed using an ultraviolet-visible spectrometer. Based on the obtained results, mathematical relationships between concentration and absorbance were defined. The calculated concentration of different elements using the developed relationships was compared with the measured concentration using ICP-OES to find any deviation between the two. The effect of various parameters such as concentration, path length, number of elements in the solution, density, and pH was analyzed to verify the feasibility. The obtained results show that this technique can be effectively used to measure the concentration of nickel and cobalt with high accuracy.

Effect of Thickness on the Optical and Electrical Properties of ITO/Au/ITO Sandwich Structures.

Tin-doped indium oxide (ITO)/Au/ITO sandwich structures with varying top and bottom ITO film thicknesses were deposited by magnetron sputtering. The effects of varying thickness of the two ITO films on the structural, electrical, and optical properties of the sandwich structures were investigated. X-ray diffraction spectra showed that by inserting an ultrathin Au film, the average grain size of the top ITO layer was significantly increased, but not for the bottom one. The optical properties of the sandwich structures were measured by transmittance measurement and spectroscopic ellipsometry. In the symmetric structure, where the top and the bottom ITO layers had the same thickness, we demonstrated that the crossover wavelength can be changed from the visible range (830 nm) to the near-infrared range (1490 nm) by increasing the top as well as bottom ITO thickness, corresponding to a plasmonic tuning ability of over 600 nm. The evaluation of this trilayer structure as a plasmonic device was asserted based on three quality factors. A comparison of the performance of this trilayer structure with conventional materials was also discussed.

A Randomized Controlled Trial of Chinese Medicine on Nonmotor Symptoms in Parkinson's Disease.

Nonmotor symptoms (NMS) of Parkinson's disease (PD) have devastating impacts on both patients and their caregivers. Jiawei-Liujunzi Tang (JLT) has been used to treat some NMS of PD based on the Chinese medicine theory since Qing dynasty. Here we report a double-blind, randomized, placebo-controlled, add-on clinical trial aiming at evaluating the efficacy and safety of the JLT in treating NMS in PD patients. We randomly assigned 111 patients with idiopathic PD to receive either JLT or placebo for 32 weeks. Outcome measures were baseline to week 32 changes in Movement Disorder Society-Sponsored Revision of Unified PD Rating Scale (MDS-UPDRS) Parts I-IV and in NMS assessment scale for PD (NMSS). We observed improvements in the NMSS total score (p = 0.019), mood/cognition (p = 0.005), and reduction in hallucinations (p = 0.024). In addition, post hoc analysis showed a significant reduction in constipation (p < 0.001). However, there was no evidence of improvement in MDS-UPDRS Part I total score (p = 0.216) at week 32. Adverse events (AEs) were mild and comparable between the two groups. In conclusion, long-term administration of JLT is well tolerated and shows significant benefits in improving NMS including mood, cognition, and constipation.

Prevalence of visual impairment and refractive errors among different ethnic groups in schoolchildren in Turpan, China.

BACKGROUND: There is currently limited information about ethnic differences in myopia prevalence within mainland China, especially in rural or semi-rural areas. We examined the prevalence of refractive errors, visual impairment and spectacle coverage in school children of varying ethnicity in Turpan, Xinjiang province. METHODS: A community eye care service was provided for five schools. Presenting monocular distance and near visual acuity (VA), and ocular alignment were assessed. Retinoscopy and cycloplegic subjective refraction were performed for participants with presenting visual impairment (distance VA worse than 0.3 logMAR; Snellen 6/12 or 20/40) or abnormal binocular vision. Questionnaires administered prior to the eye examinations were used to collect information regarding personal lifestyle and parental myopia. RESULTS: A total of 646 out of 690 (94%) subjects aged four to 19 years (11.9 ± 2.6; mean ± S.D.) completed the eye examination. Three hundred and eighty-two (59%) of participants were of Uyghur ethnicity, followed by Han, 176 (27%) and Hui, 74 (12%). The mean age of Uyghur, Han and Hui students was 12.3 ± 2.7, 11.4 ± 2.6 and 11.4 ± 2.3 years respectively, in which the Uyghur students were significantly older than the Han and Hui students (F(3,631) = 5.58 p < 0.001). In total, 170 (27%) and 85 (13%) subjects failed the screening examination for one eye or both eyes, respectively. The prevalence of presenting visual impairment was not significantly different among the ethnic groups (p = 0.26). After cycloplegic refraction, most subjects' VA (98%) improved to better than 0.3 logMAR (Snellen 6/12 or 20/40). The prevalence of "clinically-significant myopia" (≤-0.50 dioptres) was 27%, 18% and 13% in Han, Hui and Uyghur children, respectively (p < 0.001). In contrast, Uyghur students had the highest prevalence of astigmatism (Uyghur 12%, Han 5%, Hui 4%). The overall spectacle coverage was 36%, while spectacle coverage among ethnic groups were similar (Han, 41%; Uyghur, 32%; Hui, 41%; χ(2) = 2.23, df = 2, p = 0.33). CONCLUSION: The prevalence of clinically significant myopia varied markedly with ethnicity in school children sampled from a semi-rural region of mainland China (Han > Hui > Uyghur). As reported previously, uncorrected/under-corrected refractive error was the main cause of presenting visual impairment.

Elevated catalytic activity of ruthenium(II)-porphyrin-catalyzed carbene/nitrene transfer and insertion reactions with N-heterocyclic carbene ligands.

Bis(NHC)ruthenium(II)-porphyrin complexes were designed, synthesized, and characterized. Owing to the strong donor strength of axial NHC ligands in stabilizing the trans M=CRR'/M=NR moiety, these complexes showed unprecedently high catalytic activity towards alkene cyclopropanation, carbene C-H, N-H, S-H, and O-H insertion, alkene aziridination, and nitrene C-H insertion with turnover frequencies up to 1950 min(-1). The use of chiral [Ru(D4-Por)(BIMe)2] (1 g) as a catalyst led to highly enantioselective carbene/nitrene transfer and insertion reactions with up to 98% ee. Carbene modification of the N terminus of peptides at 37 °C was possible. DFT calculations revealed that the trans axial NHC ligand facilitates the decomposition of diazo compounds by stabilizing the metal-carbene reaction intermediate.

The involvement of serotonin metabolism in cigarette smoke-induced oxidative stress in rat lung in vivo.

Recently, we have reported the dysregulation of circulating serotonin (5-hydroxytryptamine, 5-HT) homeostasis in patients with chronic obstructive pulmonary disease (COPD). An increase in metabolism of 5-HT has been reported to induce oxidative stress via monoamine oxidase (MAO)-dependent pathway. The present study aimed at investigating the effect of cigarette smoke exposure on the systemic circulation and local airway 5-HT levels as well as MAO-mediated oxidative pathway using a cigarette smoke-exposed rat model. Male Sprague-Dawley rats (150-200 g) were exposed to either sham air or 4% (v/v, smoke/air) cigarette smoke for 1 hour daily for 56 consecutive days. Sera, bronchoalveolar larvage (BAL) and lung tissues were collected 24 hours after the last exposure. We found a significant reduction in the reduced glutathione (rGSH) and an elevation in advanced oxidation protein products (AOPP), a protein oxidation marker, in the lung of cigarette smoke-exposed group (p < 0.05). A significant increase in 5-HT was found in serum (p < 0.05), but not in the BAL or lung, after cigarette smoke exposure. MAO-A activity was significantly elevated in the lung of cigarette smoke-exposed group (p < 0.05). Furthermore, increased superoxide anion levels were found in lung homogenates of cigarette smoke-exposed rats after incubation with 5-HT (p < 0.05), which was positively associated with the increase in MAO-A activity (r = 0.639, p < 0.05). Our findings supported the presence of GSH disruption and protein oxidation in the lung after cigarette smoke exposure. The metabolism of 5-HT by MAO-A in the lung enhanced cigarette smoke-induced superoxides, which might contribute to the pathogenesis of COPD.

Inhibitory effect of Chinese green tea on cigarette smoke-induced up-regulation of airway neutrophil elastase and matrix metalloproteinase-12 via antioxidant activity.

Our recent study has indicated that Chinese green tea (Lung Chen), in which epigallocatechin-3-gallate (EGCG) accounts for 60% of catechins, protected cigarette smoke-induced lung injury. We now hypothesized that Lung Chen tea may also have potential effect on lung oxidative stress and proteases/anti-proteases in a smoking rat model. Sprague-Dawley rats were exposed to either sham air (SA) or 4% cigarette smoke (CS) plus 2% Lung Chen tea or water by oral gavage. Serine proteases, matrix metalloproteinases (MMPs) and their respective endogenous inhibitors were determined in bronchoalveolar lavage (BAL) and lung tissues by gelatin/casein zymography and biochemical assays. Green tea consumption significantly decreased CS-induced elevation of lung lipid peroxidation marker, malondialdehyde (MDA), and CS-induced up-regulation of neutrophil elastase (NE) concentration and activity along with that of α(1)-antitrypsin (α(1)-AT) and secretory leukoproteinase inhibitor (SLPI) in BAL and lung. In parallel, significant elevation of MMP-12 activity was found in BAL and lung of the CS-exposed group, which returned to the levels of SA-exposed group after green tea consumption but not CS-induced reduction of tissue inhibitor of metalloproteinase (TIMP)-1 activity, which was not reversed by green tea consumption. Taken together, our data supported the presence of local oxidative stress and protease/anti-protease imbalance in the airways after CS exposure, which might be alleviated by green tea consumption through its biological antioxidant activity.

Cigarette smoke-induced cerebral cortical interleukin-6 elevation is not mediated through oxidative stress.

The author group has previously established an in vivo subchronic cigarette smoke (CS) exposure rat model, in which the systemic oxidative burden as well as the modulation of local anti-oxidative enzymes in the lung has been demonstrated. Oxidative stress has been shown to induce pro-inflammatory cytokine release, including interleukin (IL)-6 in the airways. In this study, we aimed to investigate the changes in IL-6 production, as well as the oxidative/anti-oxidative responses in the cerebral cortex using the same in vivo model. IL-6 was determined by RT-PCR and western-blot analysis. Local oxidative and anti-oxidative responses were determined by measuring cerebral cortical malondialdehyde (MDA) and advanced oxidation protein product (AOPP) levels, superoxide dismutase (SOD) and catalase activities, and the reduced to oxidized glutathione (GSH/GSSG) ratio. Nitrite level was measured by fluorescent spectrophotometry. Our results demonstrated a significant increase in both IL-6 mRNA and protein levels. Reductions of SOD activity and manganese (Mn)SOD protein level were observed together with the increased level of superoxide measured by chemiluminescent signal, after 56 days of CS exposure. There were no significant changes in the cerebral cortical levels of MDA, AOPP, catalase activity, and the GSH/GSSG ratio. Nitrite level was significantly reduced, together with the decreased protein level of nNOS in the cerebral cortex, after 56 days of CS exposure. Our results suggest that exposure to CS induces IL-6 expression in the cerebral cortex, which is not mediated by the oxidative/anti-oxidative imbalance.

The reproducibility and short-term and long-term repeatability of sonographic measurement of splenic length.

This study was undertaken to evaluate the reproducibility (interobserver variability), and the short-term and long-term repeatability (intraobserver variability) of sonographic measurement of the maximum and mean splenic length. Ultrasound (US) measurements of the splenic length were performed in 43 subjects, ages 30 to 59 years old (mean age = 44.5 years). Each subject attended three US sessions: baseline examination and 30 min and 8 weeks after the baseline examination. In each session, US examinations of the spleen were performed and the splenic length was measured by four operators. In each examination, the splenic length was measured 3 times, and the maximum and mean values were obtained. The overall reproducibility of the measurements of maximum and mean splenic lengths were 67% and 89%, respectively. The short-term repeatability in measuring the maximum and mean splenic lengths were 87% and 94%, respectively, whereas the long-term repeatabilities were 61% and 76%, respectively. The reproducibility and short-term and long-term repeatability of the measurement of mean splenic length were higher than those of the maximum splenic length. In the mean and maximum splenic length measurement, the short-term repeatability was higher than the long-term repeatability. The results suggested that the mean splenic length has a higher reliability in sonographic measurement and should be used in routine clinical practice. Measurement errors should be considered when evaluating the changes of splenic length in serial US examinations, particularly in long-term follow-up.