Pain Symptoms in Optic Neuritis.

Signs and symptoms of optic neuritis (ON), an autoimmune disorder of the central nervous system (CNS), differ between patients. Pain, which is commonly reported by ON patients, may be the major reason for some patients to visit the clinic. This article reviews the presence of pain related to ON with respect to underlying disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein associated disease (MOGAD). The aim of this review is to provide an overview of pain symptoms in accordance with the context of various pathophysiological explanations, assist in differential diagnosis of ON patients, especially at the onset of disease, and make recommendations to aid physicians make decisions for follow up diagnostic examinations.

Ear-like poly (acrylic acid)-activated carbon nanocomposite: A highly efficient adsorbent for removal of Cd(II) from aqueous solutions.

Poly (acrylic acid) modified activated carbon nanocomposite (PAA-AC) was synthesized. The structure and morphology of this nanocomposite were characterized by FTIR, SEM, TEM, XRD and Zeta potential. The adsorption of some heavy metal ions on PAA-AC was studied. The characterization results indicated that PAA-AC was a novel and ear-like nanosheet material with the thickness of about 40 nm and the diameter of about 300 nm. The adsorption results exhibited that the introduction of carboxyl groups into activated carbon evidently increased the uptake for heavy metal ions and the nanocomposite had maximum uptake for Cd(II). Various variables affecting adsorption of PAA-AC for Cd(II) were systematically explored. The maximum capacity and equilibrium time for adsorption of Cd(II) by PAA-AC were 473.2 mg g-1 and 15 min. Moreover, the removal of Cd(II) for real electroplating wastewater by PAA-AC could reach 98.5%. These meant that the removal of Cd(II) by PAA-AC was highly efficient and fast. The sorption kinetics and isotherm fitted well with the pseudo-second-order model and Langmuir model, respectively. The adsorption mainly was a chemical process by chelation. Thermodynamic studies revealed that the adsorption was a spontaneous and endothermic process. The results revealed that PAA-AC could be considered as a potential candidate for Cd(II) removal.

Preparation and characterization of poly (itaconic acid)-grafted crosslinked chitosan nanoadsorbent for high uptake of Hg2+ and Pb2.

A novel nanoadsorbent (PIACS) with average size of 52.6nm was prepared by controlling grafted polymerization of itaconic acid on chitosan to emulsion stage and then crosslinking with glutaraldehyde. The preparation conditions were optimized and PIACS was characterized by FT-IR, XRD, SEM, TEM and TGA. The adsorption of PIACS for some metal ions was studied. The adsorption results showed that PIACS for adsorption of Hg2+ and Pb2+ had higher uptakes than some reported adsorbents. Various variables for adsorption of Hg2+ and Pb2+ were systematically researched. The adsorption followed the pseudo-second-order kinetics and Langmuir isotherm models. The maximum uptakes of Hg2+ and Pb2+ from Langmuir model were 870.1mgg-1 and 1320mgg-1, respectively. Especially, the uptake of this nanoadsorbent for Pb2+ was 4 times of that of the macro-scale adsorbent with the similar structure reported. As temperature rising, uptake of Pb2+ decreased while uptake of Hg2+ almost had no change. In addition, the adsorbent could be regenerated with EDTA. Hence, this prepared method of nanomaterial might extend to the similar grafted polymerizing and crosslinking systems of polymers and PIACS would be a promising adsorbent in the removal of Hg2+ and Pb2+ from wastewaters.

Impact of human activity and natural processes on groundwater arsenic in an urbanized area (South China) using multivariate statistical techniques.

Anthropogenic factors resulted from the urbanization may affect the groundwater As in urbanized areas. Groundwater samples from the Guangzhou city (South China) were collected for As and other parameter analysis, in order to assess the impact of urbanization and natural processes on As distribution in aquifers. Nearly 25.5 % of groundwater samples were above the WHO drinking water standard for As, and the As concentrations in the granular aquifer (GA) were generally far higher than that in the fractured bedrock aquifer (FBA). Samples were classified into four clusters by using hierarchical cluster analysis. Cluster 1 is mainly located in the FBA and controlled by natural processes. Anthropogenic pollution resulted from the urbanization is responsible for high As concentrations identified in cluster 2. Clusters 3 and 4 are mainly located in the GA and controlled by both natural processes and anthropogenic factors. Three main mechanisms control the source and mobilization of groundwater As in the study area. Firstly, the interaction of water and calcareous rocks appears to be responsible for As release in the FBA. Secondly, reduction of Fe/Mn oxyhydroxides and decomposition of organic matter are probably responsible for high As concentrations in the GA. Thirdly, during the process of urbanization, the infiltration of wastewater/leachate with a high As content is likely to be the main source for groundwater As, while NO3 (-) contamination diminishes groundwater As.

[Distribution and sources of arsenic in Yangzonghai Lake, China].

By collecting water and sediment samples from Yangzonghai Lake and analyzing the total amount and speciation of arsenic, the spatial distribution of arsenic in surface water and sediments was analyzed, the current status of arsenic pollution were estimated, the anthropogenic contribution rate and the arsenic reserve in the lake were calculated respectively. Meanwhile, the sources of arsenic were investigated. The results indicated that the total arsenic content in Yangzonghai Lake was 71.96-101.2 microg x L(-1) in April, 2010, and increased slightly with depth. Dissolved arsenic content was 68.14-96.72 microg x L(-1), with As (III) accounting for 32%. The health risk level of arsenic in the water was 4.77 x 10(-4) - 6.66 x 10(-4) a(-1), posing a considerable threat to the surrounding environment. Arsenic content in sediments lied between 6.05-396.49 mg x kg(-1). In sediments at the depths of 0-2, 2-4, 4-6, 6-8 and 8-10 cm, the average arsenic contents were 155.66, 52.01, 29.78, 19.22 and 17.52 mg x kg(-1) respectively. Arsenic in sediments at 0-2 cm had the highest accumulation degree, with the maximum geoaccumulation index up to 5. At the deeper depths, the accumulation degree of arsenic significantly lowered. The sequence of arsenic average contents of seven forms in sediments in the descending order is residual fraction, humic acids fraction, oxide fraction, strong organic fraction, ion exchange fraction, water soluble fraction and carbonate fraction. With increase of sediments depths, the percentage of bioavailable arsenic decreased, and the percentage of residual fraction arsenic increased rapidly. The anthropogenic contribution rate of arsenic in sediments was the highest at 0-2 cm depth, with average of 81.94%. This rate was much lower at the deeper depths. Currently, the total arsenic reserve in water and sediments of Yangzonghai Lake was 70.65 t, of which 82.68% was contributed by human activities. The phosphate fertilizer plant on the south bank made the greatest contribution to arsenic accumulation in Yangzonghai Lake, followed by golf course on the east bank, thermal power station and hot spring on the north bank.