The search for new metal-organic compounds as candidates for quantum information processing technologies is in the spotlight. Several metal ions and organic linkers have been used to obtain such compounds. Herein, we describe the synthesis, crystal structures, and cryomagnetic properties of two air-stable isostructural neodymium(III) and europium(III) one-dimensional (1D) coordination polymers of formula [Nd(Hmpa)(DMSO)] (1) and [Eu(Hmpa)(DMSO)] (2) [Hmpa=N-(4-methylphenyl)oxamate, and DMSO=dimethylsulfoxide].
View Article and Find Full Text PDFDeveloping and investigating advanced multifunctional materials with magnetic properties as candidates for assembling spin qubits for quantum computing is imperative. A new polytopic ligand based on oxamate and aniline was used to promote the synthesis of three neutral homometallic lanthanide-coordinated polymers. New complexes with the formula {Ln(phox)(DMSO)(HO)}, where Ln = Eu (1), Gd (2), and Tb (3) [phox = -(phenyl)oxamate and DMSO = dimethylsulfoxide], were synthesized and well characterized by spectroscopic methods as well as X-ray crystallographic analysis.
View Article and Find Full Text PDFActa Crystallogr C Struct Chem
August 2024
The synthesis, crystal structure and magnetic properties of an oxamate-containing erbium(III) complex, namely, tetrabutylammonium aqua[N-(2,4,6-trimethylphenyl)oxamato]erbium(III)-dimethyl sulfoxide-water (1/3/1.5), (CHN)[Er(CHNO)(HO)]·3CHOS·1.5HO or n-BuN[Er(Htmpa)(HO)]·3DMSO·1.
View Article and Find Full Text PDFAcute lymphoblastic leukemia (ALL) is the most common cancer among children worldwide, characterized by an overproduction of undifferentiated lymphoblasts in the bone marrow. The treatment of choice for this disease is the enzyme L-asparaginase (ASNase) from bacterial sources. ASNase hydrolyzes circulating L-asparagine in plasma, leading to starvation of leukemic cells.
View Article and Find Full Text PDFPurpose: Muscle-invasive bladder cancer (MIBC) is an aggressive disease with a complex treatment. In Brazil, as in most developing countries, data are scarce, but mortality seems exceedingly high. We have created a centralization program involving a multidisciplinary clinic in a region comprising seven municipalities.
View Article and Find Full Text PDFWe report the unique heterobimetallic dodecanuclear oxamate-based {CoII6CuII6} nanowheel obtained using an environmentally friendly synthetic protocol. The effective Hamiltonian methodology employed herein allows the rationalisation of magnetic isotropic or anisotropic metal clusters, being a significant advance for future studies of exciting properties only observed at low and ultralow temperatures.
View Article and Find Full Text PDFIn this work, we present the synthetic pathway, a refined structural description, complete solid-state characterization and the magnetic properties of four new cobalt(ii) compounds of formulas [Co(HO)][Co(Hmpba)]·2HO·0.5dmso (1), [Co(HO)][Co(Hmpba)]·3HO·0.5dpss (2), [Co(Hmpba)(HO)]·4nHO (3), and [Co(Hmpba)(CHOH)(HO)]·0.
View Article and Find Full Text PDFThis paper presents an empirically grounded call for a more nuanced engagement and situatedness with placial characteristics within a spatial epidemiology frame. By using qualitative data collected through interviews and observation to parameterise standard and spatial regression models, and through a critical interpretation of their results, we present initial inroads for a situated spatial epidemiology and an analytical framework for health/medical geographers to iteratively engage with data, modelling, and the context of both the subject and process of analysis. In this study, we explore the socioeconomic factors that influence homicide rates in the Brazilian state of Alagoas from a critical public health perspective.
View Article and Find Full Text PDFTwo air-stable, isostructural, mononuclear six-coordinate manganese(II) and cobalt(II) oxamate complexes, [(4-HOpa)(HO)] [4-HOpa = -4-hydroxyphenyloxamate; = Mn () or Co ()], exhibit field-induced slow magnetic relaxation. A bottleneck process is observed throughout the temperature range of 2-20 K for , while for , it dominates only at low temperatures (2-4 K). Additionally, the Raman process [ = 6.
View Article and Find Full Text PDFImplementing additional optical (luminescent) properties into the well-known class of single-molecule magnets (SMMs) is considered as a promising route toward obtaining the next generation of optomagnetic materials for quantum information storage and computing. Herein, we report a joint optical and magneto-structural study for the two novel series of lanthanide(iii) complexes of general formula Bu4N[LnIII(HL)4(dmso)]·nH2O where H2L = N-(4-Xphenyl)oxamic acid with X = Cl and n = 2 [Ln = Eu (1_Cl), Gd (2_Cl), Dy (3_Cl), and Tb (4_Cl)] and X = F and n = 3 [Ln = Eu (1_F), Gd (2_F), Dy (3_F), and Tb (4_F)]. All these compounds are mononuclear species with each lanthanide(iii) cation in a low-symmetry nine-coordinate environment (LnO9) which is constituted by four didentate monoprotonated oxamate groups and one dmso molecule.
View Article and Find Full Text PDFOligonucleotides, peptides, and peptide nucleic acids incorporating 7-oxanorbornene as a dienophile were reacted with tetrazines linked to either a peptide, d-biotin, BODIPY, or -acetyl-d-galactosamine. The inverse electron-demand Diels-Alder (IEDDA) cycloaddition, which was performed overnight at 37 °C, in all cases furnished the target conjugate in good yields. IEDDA reactions with 7-oxanorbornenes produce a lower number of stereoisomers than that of IEDDA cycloadditions with other dienophiles.
View Article and Find Full Text PDFBackground & Aims: Sepsis is still a significant cause of death in the Intensive Care Unit and its early diagnosis is vital. Changes in cell permeability have been observed early in sepsis. Lower values of bioelectrical impedance (BIA) such as reactance adjusted by height (Xc/H) and phase angle (PA) have already been studied as a prognostic biomarker for many diseases and may indicate cell injury.
View Article and Find Full Text PDFPb27 antigen is an interesting alternative to immunological diagnosis of Paracoccidioidomycosis (PCM) and has demonstrated to be protective in experimental PCM. Its tertiary structure and possible function remained unknown till now. To study Pb27 at the atomic level, the recombinant protein was expressed in Escherichia coli BL21(DE3), purified, and its three-dimensional structure was solved by X-ray crystallography.
View Article and Find Full Text PDFAddition of small molecule Retro-1 has been described to enhance antisense and splice switching oligonucleotides. With the aim of assessing the effect of covalently linking Retro-1 to the biologically active oligonucleotide, three different derivatives of Retro-1 were prepared that incorporated a phosphoramidite group, a thiol or a 1,3-diene, respectively. Retro-1⁻oligonucleotide conjugates were assembled both on-resin (coupling of the phosphoramidite) and from reactions in solution (Michael-type thiol-maleimide reaction and Diels-Alder cycloaddition).
View Article and Find Full Text PDFThe cysteine-cyclopentenedione reaction can be combined with the copper(i)-catalyzed azide-alkyne cycloaddition provided that the former is carried out first. If not, the azide and the cyclopentenedione undergo a 1,3-dipolar cycloaddition, which furnishes triazole-containing compounds and products resulting from nitrogen loss. Both of these products were fully characterized.
View Article and Find Full Text PDFUnprotected linear peptides containing N-terminal cysteines and another cysteine residue can be simultaneously cyclized and derivatized using 2,2-disubstituted cyclopentenediones. High yields of cyclic peptide conjugates may be obtained in short reaction times using only a slight excess of the cyclopentenedione moiety under TEMPO catalysis and in the presence of LiCl.
View Article and Find Full Text PDFThe outcome of the Michael-type reaction between thiols and 2,2-disubstituted cyclopentenediones varies depending on the thiol. Stable compounds with two fused rings were formed upon reaction with 1,2-aminothiols (such as N-terminal cysteines in peptides). Other thiols gave reversibly Michael-type adducts that were in equilibrium with the starting materials.
View Article and Find Full Text PDFThe reaction between maleimides and resin-linked diene-polyamides allows the latter to be used in the preparation of conjugates. Conjugation takes place by reacting the insoluble, hydrophobic diene component either with water-soluble dienophiles or with dienophiles requiring mixtures of water and organic solvents. Experimental conditions can be adjusted to furnish the target conjugate in good yield with no need of adding large excesses of soluble reagent.
View Article and Find Full Text PDFThis manuscript reviews the possibilities offered by 2,5-dimethylfuran-protected maleimides. Suitably derivatized building blocks incorporating the exo Diels-Alder cycloadduct can be introduced at any position of oligonucleotides, peptide nucleic acids, peptides and peptoids, making use of standard solid-phase procedures. Maleimide deprotection takes place upon heating, which can be followed by either Michael-type or Diels-Alder click conjugation reactions.
View Article and Find Full Text PDFJ Gastrointestin Liver Dis
March 2015
The internal ribosome entry site (IRES) element located at the 5'untranslated genomic region of various RNA viruses mediates cap-independent initiation of translation. Picornavirus IRES activity is highly dependent on both its structural organization and its interaction with host factors. Small molecules able to interfere with RNA function are valuable candidates for antiviral agents.
View Article and Find Full Text PDFIntroduction: The innate immune response molecules and their use as a predictor of mortality in cancer patients with severe sepsis and septic shock are poorly investigated.
Objective: To analyze the value of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor α (TNF-α), soluble triggering receptor expressed on myeloid cells 1 (sTREM-1), and high-mobility group box 1 (HMGB-1) as predictors of mortality in cancer patients with severe sepsis and septic shock compared with septic patients without malignancies.
Design: Prospective, observational cohort study.
Two new trinuclear copper(ii) complexes without end-capping ligands, (Bu4N)2[Cu(dmso)2{Cu(dnopba)(dmso)}2] () and (Bu4N)2[Cu(dmso)2{Cu(dcopba)(dmso)}2] () [dnopba = 4,5-dinitro-ortho-phenylenebis(oxamate), dcopba = 4,5-dichloro-ortho-phenylenebis(oxamate), Bu4N(+) = tetra-n-butylammonium and dmso = dimethylsulfoxide], were synthesized and their structures were determined by single crystal X-ray diffraction. The crystal structures of and consist of two outer bis(oxamato)(dmso)cuprate(ii) units which act as bidentate ligands toward a trans-bis(dmso)copper(ii) inner entity leading to centrosymmetric tricopper(ii) complexes with copper-copper separations across the oxamate bridges of 5.1916(3) () and 5.
View Article and Find Full Text PDFCytoplasmic polyadenylation is regulated by the interaction of the cytoplasmic polyadenylation element binding proteins (CPEB) with cytoplasmic polyadenylation element (CPE) containing mRNAs. The CPEB family comprises four paralogs, CPEB1-4, each composed of a variable N-terminal region, two RNA recognition motif (RRM) and a C-terminal ZZ-domain. We have characterized the RRM domains of CPEB4 and their binding properties using a combination of biochemical, biophysical and NMR techniques.
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