The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice / 中华劳动卫生职业病杂志

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1β and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

Rare earth elements contents and distribution characteristics in nasopharyngeal carcinoma tissue / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To investigate the rare earth elements(REEs) contents and distribution characteristics in nasopharyngeal carcinoma( NPC) tissue in Gannan region.@*METHOD@#Thirty patients of NPC in Gannan region were included in this study. The REEs contents were measured by tandem mass spectrometer inductively coupled plasma(ICP-MS/MS) in 30 patients, and the REEs contents and distribution were analyzed.@*RESULT@#The average standard deviation value of REEs in lung cancer and normal lung tissues was the minimum mostly. Light REEs content was higher than the medium REEs, and medium REEs content was higher than the heavy REEs content. REEs contents changes in nasopharyngeal carcinoma were variable obviously, the absolute value of Nd, Ce, Pr, Gd and other light rare earth elements were variable widely. The degree of changes on Yb, Tb, Ho and other heavy rare earth elements were variable widely, and there was presence of Eu, Ce negative anomaly(δEu=0. 385 5, δCe= 0. 523 4).@*CONCLUSION@#The distribution characteristic of REEs contents in NPC patients is consistent with the parity distribution. With increasing atomic sequence, the content is decline wavy. Their distribution patterns were a lack of heavy REEs and enrichment of light REEs, and there was Eu , Ce negative anomaly.

Sequential extraction for evaluating the behaviour of selected chemical elements in light weight aggregates manufactured from mining and industrial wastes

The chemical extraction of twenty-nine elements in a washing aggregate sludge, a clay-rich sediment, a sewage sludge, the mixtures of these materials and the artificial lightweight aggregates [LWAs] manufactured with them was determined by applying the optimized European Community Bureau of Reference sequential extraction procedure in order to establish the effect of the thermal treatment on the extraction of the selected elements. In accordance with the UNE-EN-1744-3 standard [2003], which states a single extraction procedure, preparation of eluates by aggregate leaching was also carried out. All the elements are mainly associated with the residual fraction in the LWAs so their availability is relatively low. The element that presented the highest concentration in the eluates after completion of the single extraction procedure was Fe. All the studied elements are in concentrations below the limit values for inert wastes so, from the standpoint of chemical leaching, the studied LWAs may be used in lightweight concrete manufacturing

Physiological effects of rare earth elements and their application in traditional Chinese medicine / 中国中药杂志

The process in the studies on physiological effects of rare earth elements in plants and their action mechanisms were summarized in the aspects of seed germination, photosynthesis, mineral metabolism and stress resistance. And the applications of rare earth elements in traditional Chinese medicine (TCM) in recent years were also overviewed, which will provide reference for further development and application of rare earth elements in TCM.

A survey of 16 rare Earth elements in the major foods in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The aim of this survey was to investigate the level of contamination of the most consumed foods in China with 16 rare earth elements (REEs), and to provide the basic data for establishing and revising food safety standards for REEs.</p><p><b>METHODS</b>Sixteen REEs in foods were measured by inductively coupled plasma-mass spectrometry (ICP-MS) in the labs of the Centers for Disease Control and Prevention of four provinces and two municipalities, during 2009-2010.</p><p><b>RESULTS</b>1 231 samples were analyzed and 19 121 concentration data of 16 REEs were collected. The REEs levels in the investigated foods varied significantly. The concentrations of cerium (Ce), dysprosium (Dy), yttrium (Y), lanthanum (La), and neodymium (Nd) were relatively high, while the remaining eleven REEs were at low levels. The mean values of total rare earth element oxides (REOs) in cereals, fresh vegetables, fresh aquatic products, fresh meats and eggs varied from 0.052 mg/kg to 0.337 mg/kg.</p><p><b>CONCLUSION</b>16 REEs in the major foods were at very low contamination levels in the investigated regions.</p>

Avaliação da força de repulsão entre magnetos de neodímeo ferro boro usados em tratamentos intra e extra bucais / Evaluation of repulsion force between Neodymium Iron Boron magnets used for intra and extra oral treatments

Os magnetos de Neodímio Ferro Boro (Nd2Fe14B) apresentam excelentes propriedades magnéticas e compatibilidade biológica, embora sejam frágeis e possuam baixa resistência à corrosão. As forças de atração magnética de magnetos de terras raras têm sido empregadas em sistemas de retenção, principalmente associadas aos implantes osseointegráveis, em próteses bucais e próteses faciais, bem como em aparelhos ortodônticos. Este estudo avalia o comportamento das forças de repulsão magnética, em função do volume e comprimento do eixo magnético, quando submetidos a afastamentos, de modo que esta propriedade física seja empregada em odontologia. Vinte e quatro corpos de prova, com um ou dois pares de magnetos de Nd2Fe14B, com diferentes formas e volumes variados, foram submetidos a ensaio mecânico para mensuração das forças de repulsão magnética, em condições de afastamentos que variaram entre 0,0 e 20,0 mm. Os dados observados mostram que, considerando-se uma mesma área superficial de polo, a força de repulsão magnética varia em função do comprimento do eixo magnético. Os dados relativos ao afastamento foram submetidos a análise de variância (p0,05), tendo-se observado que o aumento da distância entre os magnetos diminui significantemente a força de repulsão magnética na maioria dos corpos de prova. No afastamento 0,0 mm as forças magnéticas de repulsão dos subgrupos mantêm uma sequência crescente a partir do subgrupo de menor volume de magnetos ao subgrupo de maior volume de magnetos, os quais permanecem nessa sequência nos afastamentos iniciais

A força de repulsão magnética gerada por magnetos pequenos varia menos em função do aumento do afastamento. Conclui-se que a variação da força de repulsão magnética, dada a mesma área superficial de polo, apresenta uma relação direta com o volume e com o eixo magnético onde, quanto maior o volume ou o comprimento do eixo magnético, maior a força de repulsão magnética. A relação direta entre volume e força de repulsão magnética não se altera frente aos afastamentos inicais, tendendo a se tornar imensurável com o aumento da distância. A força de repulsão magnética mantém uma relação inversa com a distância entre os pares de magnetos. Este ensaio mecânico indica que a força de repulsão magnética apresenta, assim como a força de atração magnética, uma curva hiperbólica de redução frente ao aumento do afastamento.

Neodymium Iron Boron (Nd2Fe14B) magnets exhibit excellent magnetic properties and demonstrate biological compatibility, despite of their fragility and low resistance to corrosion. The magnetic attraction forces of rare earth magnets have been used in retention systems mainly associated with osseointegrated implants, in oral and facial prostheses, as well as orthodontic appliances. This study evaluates the repulsion forces of magnets, varying volume and length of magnetic axis when subjected to vertical distance, in order to assess the usefulness of such physical property in clinical situations. Twenty-four specimens, with one or two pairs of Nd2Fe14B magnets, presenting different shapes and various volumes, were subjected to mechanical testing so as to measure magnetic repulsion forces, under conditions of vertical pole face separation ranging from 0.0 to 20.0 mm. Repulsive magnetic force varies depending on the length of the magnetic axis, when considering the same surface area of a pole. Analysis of Variance - (p0.05) indicated that by increasing the distance between the pairs of magnets, magnetic repulsion force significantly reduces in most of the specimens. Starting at a 0.0 mm distance, the magnetic repulsion forces keep an enhancing sequence from lower to higher magnetic volume, holding these characteristics during initials distances. Repulsion magnetic forces generated by small magnets varies less as the distance increases.

The results indicate the repulsion magnetic force variation, fixing the same pole surface area, presenting a direct relationship between volume and magnetic axis, since the increase of the volume or of the magnetic axis length leads to a higher magnetic repulsive force. The relationship between volume and magnetic repulsion force does not vary at initial distance. Nevertheless, when such distance increases, the force between the magnets significantly decreases. The magnetic repulsion force holds an inverse relationship with respect to the distance between magnets pairs. This mechanical test indicates that the magnetic repulsion force, as well the magnetic attraction force, present a hyperbolic curve of force reduction due to the increasing vertical distance.

Bio-indicators in the tropical forest of Western Ghats environment

Investigation on the natural radionuclides 238U, 232Th, 40K and natural fallout radionuclide 210Po in the prominent plants species of Western Ghats tropical forest near Kotagiri have been carried out as a part of baseline background radiation studies in the forest environment. The prominent plants species of the region Evodia roxburghiana and Eleaocarpus oblangus were chosen and concentrations of [238]U, [232]Th, [40]K and [210]Po were measured by employing gamma ray spectrometer and alpha counter. The radioactivity concentrations in plants and soils reflect the impact of the existence of igneous nature of rock in the area of study. Concentration ratios [CR] of these radionuclides, between plants and underlying soil, have been studied and results shows that the concentration ratios [CR] seem to be depend on radionuclides in soil. From careful analysis of the results, these plants could be used as an indicator to monitor these radonuclides

Inhibitory mechanisms of three compounds for chrysotile-induced biological activities / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of aluminum citrate (AC), rare earth compounds (REC) and sodium selenite (SS) on the surface elements of chrysotile fibers and the inhibitory mechanisms of three compounds for chrysotile-induced biological activities.</p><p><b>METHODS</b>After being soaked in 250, 500 and 1000 microg/ml aluminum citrate solutions, 125, 250, 500 and 1000 microg/ml mixed rare earths solutions or 125, 250, 500 and 1000 microg/ml sodium selenite solutions for 10 min or 1 hour, the fabrication and the levels of surface elements of chrysotile fibers were determined.</p><p><b>RESULTS</b>Aluminum citrate, mixed rare earths or sodium selenite all could be adsorbed by chrysotile fibers. After pretreatment of chrysotile fibers with aluminum citrate, mixed rare earths or sodium selenite solutions for 10 min or 1 hour, the corresponding elements or ion on the surface of chrysotile fibers increased with the increase of concentration of the solutions.</p><p><b>CONCLUSION</b>Pretreatment of chrysotile with aluminum citrate, mixed rare earths or sodium selenite solutions can change the fabrication and the levels of surface elements of chrysotile fibers, and inhibit the biological activities of chrysotile by "sealing" some "active sites" on the surface of chrysotile fibers.</p>

Effect of three kinds of rare earth oxides on chromaticity and mechanical properties of zirconia ceramic / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the colouration of zirconia ceramic by adding three kinds of rare earth oxides. The influence of the pigments concentration on the mechanical properties and the microstructure was also analyzed.</p><p><b>METHODS</b>Added different concentrations of CeO(2), Er(2)O(3) and Pr(6)O(11) in tetragonal zirconia poly crystals stabilized with 3 mol% yttria (3Y-T2P) powder, compacted at 200 MPa using cold isostatic pressure, and sintered to 1 400 degrees C. The heating rate was 150 degrees C/h and the dwelling time was 2 hours. The chromaticity of sintered bodies was measured with chroma meter. The relative density, hardness, flexure strength and fracture toughness were investigated as well. The phase stability of the colorized and pure zirconia was evaluated by X-ray diffraction (XRD) using an automated diffractometer. The microstructures of the specimens were evaluated by scanning electron microscope (SEM).</p><p><b>RESULTS</b>Several kinds of color achieved by the different pigments praseodym oxide, cerium oxide and erbium oxide were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value rose with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body appeared too bright. Adding three pigments influenced flexure strength of zirconia ceramic significantly, but had little influence on the hardness and fracture toughness. Microscopy revealed the relationship between the porosity and shapes of grains was correlated to strength of the diphase ceramics. No additional phase could be detected by XRD, except t-ZrO(2) in all colorized samples after sintering at 1 400 degrees C for 120 min.</p><p><b>CONCLUSIONS</b>Zirconia ceramic can be colorized by CeO(2), Er(2)O(3), and Pr(6)O(11). Pigments even in a small amount influence the mechanical properties of the colorized zirconia material, which necessitates further investigation.</p>

Effects of rare earth compounds on human peripheral mononuclear cell telomerase and apoptosis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects of rare earth exposure on human telomerase and apoptosis of human peripheral mononuclear cells (PBMNs).</p><p><b>METHODS</b>Rare earth mine lot in Xunwu county, the biggest ion absorptive rare earth mine lot of China, was selected as the study site. Another village of Xunwu county, with comparable geological structure and social environment was selected as the control site. Thirty healthy adults were randomly selected from the study site as exposure group and another 30 healthy adults randomly selected from the control site as control group. The blood content of 15 rare earth elements, including La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y, were determined by inductive coupled plasma-source mass spectrometry (ICP-MS). The total contents of rare earth elements in the blood were calculated. The TRAP and FCM assays were carried out to analyse the telomerase and apoptosis of human PBMNCs respectively.</p><p><b>RESULTS</b>In the exposure group, the concentration of La, Ce, Dy and Y were significantly higher (P<0.001), and Pr, Nd, Sm, Gd and Yb were higher than those in the control group (P<0.05). The total content of rare earth in the blood of exposure group showed significant difference compared with control group (P<0.001). Telomerase activity in PBMNs of the exposure group was higher than that in the control group (P<0.05); there were 11 adults in the exposure group (30 adults) and 5 adults in control group (30 adults) showed positive telomerase activity. The average age of the exposure group was (38.69 +/- 8.02) years-old, while the control group was (40.45 +/- 9.02) years-old (P >0.05). It was found that there was a significant relationship between telomerase activity and the total content of rare earth elements (P <0.01). 3. The proportion of apoptosis was not different between the two groups (P >0.05), but the cells in the S-phase and G2-M phase were increased (P <0.01) in the exposed group.</p><p><b>CONCLUSION</b>The telomerase activity of PBMNs in the rare earth elements exposed group was higher than that of the control group, and there is no effect on apoptotic rate of PBMNs, but may promote the diploid DNA replication, and increase the percentage of G2/M and S phase cells.</p>

Relationship of the hair content of rare earth elements in young children aged 0 to 3 years to that in their mothers living in a rare earth mining area of Jiangxi / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the relationship of hair content of rare earth elements (REEs) in the young children aged 0 - 3 years to that in their mothers living in a rare earth mining area of Jiangxi Province.</p><p><b>METHODS</b>Content of five kinds of REEs, i.e., lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) and samarium (Sm) were determined for the hair-root samples collected from 71 young children and 62 of their mothers by inductively coupled plasma source mass spectrometry (ICP-MS).</p><p><b>RESULTS</b>The mean hair content of REEs (e.g., La) was the highest (2,202.90 ng/g) in the young children living in the place nearest to the REE mining area, next (471.72 ng/g) was in those nearer to the REE mining area, and the lowest (97.37 ng/g) was in those in the control area. And, the hair content of REEs in the mothers was the same as that in their children, i.e, the mean content of La was the highest (1,510.21 ng/g) in high-exposure area, next (241.63 ng/g) was that in the low-exposure area, and the lowest (59.15 ng/g) was that in the control area, with P < 0.001. Pair-comparison analysis for the means showed that the average hair level of five kinds of REEs in the young children was two times high as their mothers' (P < 0.001). For example, the hair level of La was 533.83 ng/g in the young children and 279.78 ng/g in their mothers, respectively. Simple linear regression analysis showed that there was a significant correlation between the hair levels of each kind of REEs in the young children and those in their mothers, with a correlation coefficient of more than 0.75, e.g., that of La was 0.878 (P < 0.01).</p><p><b>CONCLUSIONS</b>The hair level of REEs can be used as a bio-marker to reflect body's level of exposure to REEs. The hair level of REEs in young children and their mothers decreased with the increase of the distance from their home to rare earth mining area. Young children living in the area with REEs mining may be the high-exposure population, and their hair level of REEs was significantly higher than that in their mothers and more attention should be paid to them.</p>

A case-control study on the risk factors of leukemia in mining areas of rare-earth in South Jiangxi / 中华流行病学杂志

<p><b>OBJECTIVE</b>In order to explore the correlation on radioactive contamination of lanthanon to leukemia, and provide clues for the causes and prevention of leukemia in mining areas of rare-earth elements.</p><p><b>METHODS</b>1:1 matched case-control study was used. A total of 51 clinically confirmed leukemia cases, individually matched with controls from general population, were interviewed in mining areas of rare-earth in South Jiangxi from November to December, 2001. Data were analyzed, using conditional logistic regression.</p><p><b>RESULTS</b>The main risk factors would include frequently drinking water from river (OR = 5.543), distance from residence to rare-earth mine and years for living in the area (OR = 3.308), exposure to organophosphorus pesticide (OR = 3.014). Tea drinking habit appeared to be a protective factor.</p><p><b>CONCLUSIONS</b>Leukemia seemed to be related to environmental pollution with rare-earth elements around the residential areas and organophosphorus pesticide exposure. The protective factor of tea drinking habit seemed to be unique in this study, which called for further studies.</p>

The effects of exposure to rare earth (NO3)3 on the immune function of mice off spring via milk / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the changes of immune function in mice offspring whose mothers were exposed to Rare Earth (RE)(NO(3))(3).</p><p><b>METHODS</b>RE(NO(3))(3) was administered to mother mice after giving birth by gavage at dosages of 2, 20 and 200 mg/kg bw during breast-feeding period. The weights of spleen and thymus, the spleen plaque forming cells (PFC), the delayed type hypersensitivity (DTH) and the charcoal clearance of the offspring were determined.</p><p><b>RESULTS</b>The results obtained from the offspring after weaning showed that the body weight of offspring treated with 200 mg/kg RE(NO(3))(3) was 18.8% lower than that of the control group; at the dosage of 2 mg/kg, the number of IgM-PFC was increased by 82.7%; and at the dosage of 20 mg/kg the rate of clearance and clearance index were significantly higher than that of the control group. No difference in DTH was found in any treated group as compared to the control group. The results of offspring at three weeks after weaning showed that the number of IgM-PFC of the 20 and 200 mg/kg bw dose groups were 47.0% and 44.7% lower than that of control group respectively; the rate of clearance and clearance index of the 200 mg/kg group were significantly lower than that of the control group. No significant changes in DTH were observed in each exposed group.</p><p><b>CONCLUSION</b>RE(NO(3))(3) treatment affected the immune function of mice offspring which may caused by breast milk.</p>

Enzyme-amplified time-resolved fluorescence detection for nucleic acid hybridization assays / 中国医学科学院学报

<p><b>OBJECTIVE</b>To develop a new nonisotopic detection method of enzyme-amplified time-resolved fluorescence (EATRF) or enzyme-amplified lanthanide luminescence (EALL) for nucleic acid hybridization assays, which can be applied extensively in clinical diagnosis.</p><p><b>METHODS</b>The method combines the high affinity of biotin-streptavidin system, amplification of enzyme, and inherent advantage of lanthanide chelate with the background elimination of time-resolved fluorescence detection. The conversion of 5-fluorosalicyl phosphate to 5-fluorosalicylic acid (5-FSA) by alkaline phosphatase. The salicylic acid product forms a luminescent ternary chelate with Tb3+ and EDTA.</p><p><b>RESULTS</b>The dynamic range of the standard curve of EATRFA for nucleic acid hybridization assay was very wide, the range was more than third order of magnitude. The detection sensitivity was about 10 pg of target sequence. When the known target sequence was 20, 10 and 2 ng, the ratio of measured amount to known amount was 110%, 90% and 115% respectively. The main experimental conditions, for example, the irradiating time of ultraviolet rays, the concentrations of biotinylated probe, AP-SA, 5-FSAP and Tb-EDTA and the methods of washing in the related steps, have been optimized. A new stable technology of fluorescence has been developted.</p><p><b>CONCLUSIONS</b>EATRF detection for nucleic acid hybridization assays is a new sensitive simple method, which has a great prospect.</p>

Actualización en el uso del sistemas pantalla-película en radiología convencional / Update in screen-film systems use in conventional radiology

En la mayoría de los Servicios y Centros Radiológicos de nuestro país se utilizan los sistemas detectores de pantalla-película de fósforos de tierras raras con emisión de luz verde y película sencible a la misma; sin embargo, en algunos Centros del Sistema Público de Salud aún se utilizan pantalla película convencionales de tungstato de calcio, que emite luz azul, con película sencible a este color (por ej: en el Hospital San Juan de Dios, Peumo, Quillota, Puerto Natales, San José de Maipo). El objetivo del presente artículo es proporcionar a los profesionales herramientas que les permitan optimizar el empleo de los sistemas detectores, que son elementos accesorios de gran importancia de la abtención de imágenes radiográficas de alta calidad diagnóstica, logrando además disminuir la dosis de irradiación al paciente y una mayor duración del tubo de rayos X, entre otras características

Mantle-crustal source of mafic-felsic magmas in the dubr-igla intrusive complex, Egypt: infference from geochemistry and Sr-Nd isotopic study

The Dubr-Igla intrusive complex [DIC] is a composite batholith intruded into the Pan-African terrain of the Egyptian basement complex. It represents an uplifted tectonic block, comprising a diverse rock association ranging from gabbro to granite. These rocks belong to two distinct suites; the gabbroid-diorite [mafic-intermediate] and granodioritemonzogranite [felsic] suites. The gabbroid-diorite suite has a calc-alkaline affinity and an overall depletion of Nb, Y, K, and Rb with slightly fractionated REE pattern [La/Yb[N]= 0.96 -3.72]. The granodiorite and monzogranites are late-to post orogenic talc-alkaline rocks with metaluminous to mildly peraluminous character and are relatively enriched in LIL. elements but depleted in HFS elements. They have fractionated REE patterns [La/1b[n]=2.62-6.97], flat HREE [Gd/Yb[N]= 0.89-1.10] and well-developed negative Eu anomalies [Eu/Eu[=0.74-3.0]. The granitoid rocks of the DIC have trace element and REE signatures characteristic of 1-type granites formed in Subduction-related arc environments. Whole-rock Rb-Sr isochron ages of the monzogranites and the diorite-quartz diorite from DIC are 644 +/- 7 Ma and 704 +/- 13 Ma, respectively. The diorite-quartz diorite shows a narrow range of ot [Nd] [+6.7-+8.5] and initial [87]Sr/[86]Sr ratio [0.7022-0.7025]. These isotopic characteristics and the overall depletion of the LIL elements and LREE and low Rb/Sr suggest that they had been derived from a depleted mantle source. The granodiorite and monzogranites have low initial [87]Sr/[86]Sr ratio [0.7025 - 0.7035] and positive spread of[Nd][+3.4 - +5.2], which indicate that their protolith was either mantle or most likely juvenile lower crust that had been separated from the mantle. Isotopic, REE data and numerical modeling performed on the three rock types of the DIC [diorite-quartz diorite, granodiorite and monzogranite] indicate that complex petrogenetic processes generated them as follow. 1] the diorite-quartz diorite was formed by 10%-15% partial melting of mantle-derived basaltic source similar in composition to the associated gabbroid rocks; 2] the monzogranites were derived through: a dehydration melting [30%] of mafic metaigneous lower crustal material due to underplating by a mantle-derived magma which supplies heat budget for melting-followed by -about 70%-80% fractional crystallization of a crustal derived- primitive granitic melt to yield the differentiated monzogranites in the DIC; 3] the granodiorite shows abundant field and petrographic evidence for variable extent of mafic-felsic magma interactions [mingling, mixing and heterogeneous hybridization]. Least squares mixing tests, using trace and major elements support the formation of the granodiorite rocks by a simple mixing of two end-members, the diorite and the less differentiated monzogranite. A proportion of the diorite end-member ranging between 15 and 50% can explain the observed chemical variations in the granodiorite

Geochemical aspects and origin of ounger granites from afif and al hijaz terranes in the arabian shield

The late Proterozoic granitoids from two terranes of different tectonic regimes, namely the Afif and Al Hijaz were studied to constrain the mature of the magmatic processes during the waning stage of crustal evolution in the Arabian Shield. The granitoid rocks from the Afif and Al Hijaz terranes include three major rock types [diorite-quartz diorite, granodiorite and monzogranite] which have wide composition range in term of major oxides, SiO[2][54.74-76.80%], Al[2]O[3] [12.29-17.27]; Fe[2]O[3][0.91- 11.63], CaO [0.57-6.62]. The granitoid rocks in the two terranes are talc-alkaline, metaluminous to mildly peraluminous and belong petrologically and chemically to the I-type granites. Although, some monzogranitic samples chemically resemble A-type granites, they still have high LILE/HFSE ratios and belong to the high Y/Nb A-subtype granites. This can be attributed to the highly fractionated nature of some monzogranites. All the granitoid rocks are depleted in Ba, Sr, Nb, Ti and Eu and enriched in K, Zr, Y, Rb and LREE. Trace element modeling indicates that the dioritequartz diorite was formed by partial melting of the lower crust. Further, two stages of differentiation are necessary to explain the origin of the granodiorite and monzogranite. An early stage, high pressure, crystal-melt fractionation was dominated by separation of plagioclase, hornblende, apatite and magnetite from dioritic magma to yield the granodiorite. Low pressure fractionation [second stage] of the granodioritic liquid yielded the ultimate composition of the monzogranites with separation of plagioclase, hornblende., biotite, apatite and magnetite. In spite of the different tectonic regimes between the Afif [continental] and 41 Hijaz [oceanic] terranes, the granitoid rocks of the two terranes show a complete overlap in term of major and most of trace element abundances. Nevertheless, the Afif granitoids are slightly more differentiated than those of the Al Hijaz terrane. Geochemiral considerations suggest that the calc-alkaline granitoids of the two terranes probably have been derived from chemically similar source regions or have evolved by comparable petrogeaetic processes. Alternatively, the long fractionation history overshadowed the parental chemical fingerprints of these rocks

Chelation behaviour of some lanthanide [III], scandium [III], yttrium [III], thorium [IV] and uranium [VI] complexes with some hydroxy nitrosocoumarins

The stability constants of the lanthanide ions [La, Ce, Pr, Nd, Sm, Gd, Dy, Er and Yb]; Sc, Y, Th and UO22+ ions with some hydroxy nitrosocoumarins were determined in 40% ethanol-water mixture at 25 degree and 0.1 ionic strength. It was found that the stability constants of the complexes increased with increasing ionic radii, from Y to Sm. The so called Gadolinium break was observed with heavier lanthanides. Sc and Th complexes possessed the highest stability constants. The potentiometric measurements and conductimetric titrations showed that 1: 1 and 1: 2 [M: L] complexes were invariably formed

Spectrophotometric studies on 5- [P-nitrophen-Ylazo] -J-acid and its complexe with trivalent Sc, Y and la ions

An organic dye, 5-[p- nitrophenylazo]-1-hydroxy-6-aminonaphthalene-3-sulfonic acid was prepared, chemically analyzed and subjected to IR spectra. The absorption spectra of this dye was investigated in aqueous solution of varying pH values. The pKp and pKa values were determined from the absorbance wavelength relations at various pH values. The complexes formed between Sc, Y and La and the active ligand were studied spectrophotometrically and by conductimetric titrations. The stability constants of the formed complexes were calculated and the effect of diverse ions was investigated. A spectrophotometric method for the precise determination of the three metal ions was proposed

Structure and substituent effect on the characteristics of some lanthanide chelates with 3-acetyl-1,5-diarylformazans

The ionization constants of a homologous series of 1-[0- carboxyphenyl]-3-acetyl-5-arylformazans have been determined potentiometrically. The substituent effect on the pK values was discussed. Furthermore, the stability constants of the formazan chelates with trivalent La, Gd and Er ions were determined. Linear relation between sigma pK of the formazans and log K of their chelates was established. The chelation affinities of formazans towards La, Gd, Er were discussed in relation to the metal ionic size, basicity and number of donor atoms in the formazan molecule. The 1: 2 [M: L] solid chelates were isolated and characterized by several techniques as ML HL.nH2O where HL = formazan, M = La, Gd or Er ion and n = 0-6