Lanthanum content and effects on growth, gas exchanges, and chlorophyll index in maize plants / Teor de lantânio e efeitos no crescimento, trocas gasosas e teor de clorofila em plantas de milho

Rare earth elements, such as lanthanum (La), have been applied to agriculture via fertilizers, aiming to increase the productivity and crop quality, such results observed mainly in China. However, the knowledge about the effect of La on maize growth, as well as for other species, despite the growing interest it is still limited. The aim of this study was to evaluate the effects of La on maize growth, La content,photosynthetic rate and chlorophyll content in maize plants in response to La treatment (0, 25, 50, 100, 150, 300 and 600 μM) in nutrient solution for three weeks. The plants were placed in geminated pots using a split-root technique. One of the pots in the geminated set was filled with a complete nutrient solution without La, while another was filled with a nutrient solution without phosphorus but containing different concentrations of La. It was verified that roots of maize plants can accumulate approximately sixty percent more La than shoots. Moreover, low La concentrations stimulated an increase in chlorophyll index,resulting in a slight increase in shoot biomass. At higher levels, La didn’t reduce growth but caused adecrease in both photosynthetic rate and chlorophyll index.

Elementos terra rara, como lantânio (La), são aplicados à agricultura via fertilizantes, com oobjetivo de aumentar a produtividade e a qualidade das culturas agrícolas, fato observado principalmente naChina. Entretanto, o conhecimento sobre o efeito de La no crescimento do milho, bem como para outrasculturas agrícolas, ainda é limitado apesar do interesse crescente. O presente estudo objetivou avaliar oefeito da aplicação de La sobre o crescimento, teor de La, fotossíntese e teor de clorofila em plantas demilho, expostas a concentrações crescentes de La (0, 25, 50, 100, 150, 300 e 600 μM) em solução nutritivapor três semanas. As plantas foram colocadas em vasos geminados usando uma técnica de raiz divisória.Um dos potes no conjunto geminado foi preenchido com solução nutritiva completa que não continha La,enquanto outra foi preenchida com solução nutritiva sem fósforo, mas contendo diferentes concentraçõesde La. Foi verificado que as raízes das plantas de milho podem acumular sessenta por cento mais La quandocomparado à parte aérea. Além disso, as baixas concentrações de La estimularam o aumento do teor declorofila, resultando em um aumento na biomassa da parte aérea. Em concentrações mais elevadas, aaplicação de La não reduziu o crescimento das plantas de milho, mas causou diminuição na taxafotossintética e no índice de clorofila.

Neurobehavioral Assessment of Rats Exposed to Yttrium Nitrate during Development / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The aim of this study was to assess the effects of yttrium nitrate on neurobehavioral development in Sprague-Dawley rats.</p><p><b>METHODS</b>Dams were orally exposed to 0, 5, 15, or 45 mg/kg daily of yttrium nitrate from gestation day (GD) 6 to postnatal day (PND) 21. Body weight and food consumption were monitored weekly. Neurobehavior was assessed by developmental landmarks and reflexes, motor activity, hot plate, Rota-rod and cognitive tests. Additionally, brain weights were measured on PND 21 and 70.</p><p><b>RESULTS</b>No significant difference was noted among all groups for maternal body weight and food consumption. All yttrium-exposed offspring showed an increase in body weight on PND 21; however, no significant difference in body weight for exposed pups versus controls was observed 2 weeks or more after the yttrium solution was discontinued. The groups given 5 mg/kg daily decreased significantly in the duration of female forelime grip strength and ambulation on PND 13. There was no significant difference between yttrium-exposed offspring and controls with respect to other behavioral ontogeny parameters and postnatal behavioral test results.</p><p><b>CONCLUSION</b>Exposure of rats to yttrium nitrate in concentrations up to 45 mg/kg daily had no adverse effects on their neurobehavioral development.</p>

Evaluation of potable groundwater quality in some villages of Adilabad in Andhra Pradesh, India.

Reconnaissance hydrochemical survey was conducted in some villages of Adilabad district, Andhra Pradesh to assess the quality of groundwater, which is mainly used for drinking purpose. The study consists of the determination of physico-chemical properties, trace metals, heavy metals and rare earth elements in water samples. The data showed the variation of the investigated parameters in samples as follows: pH 6.92 to 8.32, EC 192 to 2706 µS cm-1, TDS 129.18 to 1813.02 ppm. The pH of the waters was within the permissible limits whereas EC and TDS were above the permissible limits of World Health Organization (WHO). Total 27 elements (Li, Be, B, Na, Mg, Al, Si, K, Ca, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Ba and Pb) were analyzed using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). The concentration of elements in water samples ranged between 0.063 to 0.611 mg l-1 for B, 11.273 to 392 mg l-1 for Na, 5.871 to 77.475 mg l-1 for Mg, 0.035 to 1.905 mg l-1 for Al, 0.752 to 227.893 mg l-1 for K, 11.556 to 121.655 mg l-1 for Ca and 0.076 to 0.669 mg l-1 for Fe respectively. The concentrations of Na, Mg, Al, K, Ca, and Fe exceeded the permissible limits of WHO and BIS guidelines for drinking water quality. In the present study, Bhimavaram, Kazipalli, Kannepalli and Chennur areas of the Adilabad are especially prone to geogenic contamination. Overall water quality was found unsatisfactory for drinking purposes.

Accumulation of rare earth elements by siderophoreforming Arthrobacter luteolus isolated from rare earth environment of Chavara, India.

In this study, Arthrobacter luteolus, isolated from rare earth environment of Chavara (Quilon district, Kerala, India), were found to produce catechol-type siderophores. The bacterial strain accumulated rare earth elements such as samarium and scandium. The siderophores may play a role in the accumulation of rare earth elements. Catecholate siderophore and low-molecular-weight organic acids were found to be present in experiments with Arthrobacter luteolus. The influence of siderophore on the accumulation of rare earth elements by bacteria has been extensively discussed.

Studies on the distribution of bacterial isolates in rare earth environment.

Rare earth soil is precious, but very common across Arabian coast especially in Chavara, (Quilon district, Kerala) south west coast of India. They are widely distributed but usually occur in small amounts and enhance the soil properties. In the present study, 18 different bacterial isolates were identified from three different samples such as soil and biofilm formed on metal surfaces from the rare earth environment of Chavara using 16S rDNA gene sequencing. The accumulation of rare earth elements (REE) by microbes was studied using FT-IR analysis. In the FTIR spectrum of the test system, a peak at 1548 and 1449 cm-1 indicates the presence of aromatic nuclei (carboxylic acid), while C=C stretch for C-O-C group was noticed at 1237 cm-1. Thus significant variations in the peak position confirm the presence of carboxyl group and thus it was confirmed that rare earth elements induce the bacteria to produce carboxylic acid and thereby accumulate rare earth elements.

Inhibitory effects of LaCl_3 on hepatocellular carcinoma / 吉林大学学报(医学版)

Objective To observe the inhibitory effect of LaCl_3 on the growth of human hepatocellular carcinoma cell lines SMMC-7721 and its mechanism.Methods The cells were treated with different doses of LaCl_3 and the growth curve,colony inhibitory rates,the levels of AFP of cultured cells were detected at 1,3,5 and 7 days after they were dealed with LaCl_3.The changes of cell cycle were detected by flow cytometry and the expressions of cell cycle protein CyclinD_1,PCNA,CDK_4 and P16 were observed by immunocytochemistry staining.Results MTT test showed that SMMC-7721 cell proliterating activity was obviously inhibited by LaCl_3 in a time and dose related manner at concentrations of 0.50 and 1.00 mmol?L~(-1).The colony forming inhibitory rate of 0.10,0.50 and(1.00 mmol?L~(-1))LaCl_3 were 51%, 67% and 97% (P

Preliminary study of rare-earth elements on the growth of Ganodema lucidum / 中国药学杂志

OBJECTIVE：Rare-earth compound was added to the medium of Ganoderma lucidum to study the effect of rare-earth elements on the hypha growth,the fresh and dry weight of fruit body of G.lucidum.METHODS:The culture medium dressed with rare-earth elements.RESULTS:It showed that all concentrations of rare-earth elements had some inhibition on the hypha growth of G.lucidum.However they could make the hypha of G.lucidumwhiter.The fresh and dry weight of fruit body increased significantly when the concentrations of rare-earth elements were 100μg.g-1 and 150μg.g-1.Their raising rates were +4.13%，+0.20% and +16.47，+5.84%respectively.CONCLUSION:The yield of G.lucidum can be increased by rare-earth elements when its concentrations were 100～150μg.g-1.