Synthesis and characterization of Na2GdOPO4 and Na2LaOPO4

A new orthorhombic phase of previously reported orthorhombic Na2GdOPO4, sodium gadolinium oxyphosphate, was synthesized by solid state reactions starting with four different sets of chemicals at 1000 degrees C. The unit cell dimensions were calculated using its powder X-ray diffraction data and were found to be a = 14.709(6), b = 10.661(4) and c = 13.081(6) Angstrom and the space group is probably Pmm2 (No: 25). its monoclinic form was also obtained by further heating the orthorhombic phase at 1000 degrees C. The unit cell dimensions of the monoclinic form was found to be a = 14.719(5), b = 10.669(3), c = 13.091(5) Angstrom and beta = 92.274 degrees(2). Using the same procedure Na2LaOPO4 was also prepared the first time in this work through three sets of starting materials at 1000 degrees C. Na2LaOPO4 also crystallizes in the orthorhombic system with a = 13.657(5), b = 11.076(5), c = 6.730(3) Angstrom which seems to be isostructural with Na2GdOPO4 prepared before in our laboratory. The IR data of both Gd and La compounds agreed with the literature values. (C) 2000 Elsevier Science S.A. All rights reserved

Ferrimagnetism and metal-insulator transitions in the LaMnxRu1-xO3 perovskites

: We describe the synthesis, structure, magnetic and electrical properties of solid solutions of nominal composition, LaMnxRu1-xO3 (0 < x < 1). All the members crystallize in the GdFeO3-perovskite structure where Mn/Ru are randomly distributed at the octahedral sites. Weight losses due to hydrogen reduction, recorded using thermogravimetry, suggest considerable nonstoichiometry arising from partial oxidation of Mn/Ru to the tetravalent state. The nonstoichiometry is most likely accommodated by creating vacancies both at A and B sites of the perovskite structure, just as it occurs in LaMnO3+y. Members with x greater than or equal to 0.50 exhibit a short-range ferro/ferrimagnetic order below 150 K that is likely due to Mn-III/VI-O-Ru-III (ferrimagnetic) and Mn-III-O-Mn-VI (ferromagnetic) interactions in the perovskite structure. All the members are semiconducting including the x = 0.05 member, suggesting that a metal-insulator transition occurs in the LaMnxRu1-xO3 system for x less than or equal to 0.05

Topochemical Anion Metathesis Routes to the Zr2N2SZr_2N_2S Phases and the Na2SNa_2S and ACl Derivatives (A = Na, K, Rb)

Anion metathesis reactions between ZrNCl and A(2)S (A = Na, K, Rb) in the solid state follow three different pathways depending on reaction temperature and reactantbstoichiometry: (1) the reaction of ZrNCl with A(2)S in the 2:1 stoichiometry at 800 degreesC/72 h/in vacuo yields alpha-Zr2N2S with the expected layered structure of La2O2S. Above 850 degreesC, alpha-Zr2N2S (P (3) over bar m1; a = 3.605(1) Angstrom, c = 6.421(3) Angstrom) neatly transforms to beta-Zr2N2S (P6(3)/mmc: a = 3.602(l) Angstrom, c = 12.817(l) Angstrom). The structures of the alpha- and beta-forms are related by an a/2 shift of successive Zr2N2 layers. (2) The same reaction at low temperatures (300-400 degreesC) yields ACl intercalated phases of the formula A(x)Zr(2)N(2)SCl(x) (0 < x < similar to0.15), where alkali ions are inserted between the S/Cl...S/Cl van der Waals gap of a ZrNCl-type structure. The S and Cl ions are disordered and the c lattice parameters are alkali dependent (R (3) over barm, a similar to 3.6 Angstrom, c similar to 28.4 (Na), 28.9 (K), and 30.5 Angstrom (Rb). A(x)Zr(2)N(2)SCl, phases are hygroscopic and reversibly absorb water to give monohydrates. (3) Reaction of ZrNCl with excess A(2)S at 400-1000 degreesC gives A(2)S intercalated phases of the formula A(2alpha)Zr(2)N(2)S(1+x) (0 < X < 0.5), where the alkali ions reside between the S...S van der Waals gap of a ZrNCl type structure (R (3) over barm, a similar to 3.64 Angstrom, c similar to 29.48 Angstrom). Structural characterization of the new phases and implications of the results are described

Immunohistochemical investigation of prognostic biomarkers in resected colorectal liver metastases : A systematic review and meta-analysis

Background: Many studies have investigated the prognostic role of biomarkers in colorectal liver metastases (CRLM). However, no biomarker has been established in routine clinical practice. The aim of this study was to scrutinize the current literature for biomarkers evaluated by immunohistochemistry as prognostic markers in patients with resected CRLM. Methods: A systematic review was performed according to the PRISMA guidelines. Articles were identified in the PubMed database with selected search terms and by cross-references search. The REMARK quality criteria were applied. Markers were included if they reported the prognostic impact of immunohistochemical markers in a multivariable setting in relation to overall survival (OS). A meta-analysis was conducted when more than one original article provided survival data of a marker. Results: In total, 26 biomarkers were identified as independent significant markers for OS in resected CRLM. These biomarkers were found to be involved in multiple oncogenic signalling pathways that control cell growth, apoptosis, angiogenesis and evasion of immune detection. Among these biomarker candidates were Ki-67, EGFR, p53, hTERT, CD34, TSP-1, KISS1, Aurora kinase A and CDX2. CD34 and TSP-1 were reported as significantly associated with survival by more than one study and where therefore pooled in a meta-analysis. Conclusion: A number of independent prognostic biomarkers for resected CRLM were identified. However, most markers were evaluated in a retrospective setting with small patient cohorts, without external validation. Large, prospective, multicentre studies with standardised methods are needed before biomarkers can translated into the clinic