Early contrast enhancement of the liver: exact description of subphases using MRI

Purpose

The purpose of this study was to describe the subphases of early post-contrast enhancement of the liver, using vessel enhancement patterns, and correlate these findings with enhancement patterns of abdominal organs.

Materials and Methods

A total of 114 patients who underwent gadolinium-enhanced abdominal magnetic resonance imaging examinations constituted the final study group, of which 56 were women (age range, 3–94 years; mean, 50 years) and 58 were men (age range, 6–85 years; mean, 54 years). Early post-contrast sequences in all patients were evaluated retrospectively by two reviewers for the determination of the presence of contrast enhancement in predetermined major vessels of the abdomen and qualitative and quantitative extent of enhancement of the renal cortex, spleen, pancreas and liver. Based on the overall findings, subphases of early contrast enhancement of the liver were described and quantitative extent of enhancement of organs was correlated with subphases of early contrast enhancement of the liver. Mann–Whitney U test and one-way unbalanced analysis of variance tests were used for the comparisons.

Results

Early hepatic arterial phase was observed in 14/114 patients, mid-hepatic arterial phase in 23/114 patients, late hepatic arterial phase in 33/114 patients, splenic vein only hepatic arterial dominant phase in 20/114 patients and hepatic arterial dominant phase in 24/114 patients. There was an overall association between the subphases of enhancement and the quantitative extent of enhancement for all studied organs (P<.0001).

Conclusion

The evaluation of vessel and organ enhancement patterns has allowed the characterization of five different subphases in early post-contrast enhancement of the liver. The quantitative extent of enhancement of abdominal organs also demonstrated significant correlation with these five subphases.     

Radical substitution with azide: TMSN3-PhI(OAc)2 as a substitute of IN3

TMSN3 and PhI(OAc)2 were found to promote high-yield azide substitution of ethers, aldehydes and benzal acetals. The reaction is fast and occurs at zero to ambient temperature in acetonitrile. However, it is essential for the reaction that TMSN3 is added subsequent to the mixture of PhI(OAc)2 and the substrate. A primary deuterium kinetic isotope effect was found for the azidonation of benzyl ethers both with TMSN3-PhI(OAc)2 and with IN3. Also a Hammett free energy relationship study of this reaction showed good correlation with sigma+ constants giving with rho-values of -0.47 for TMSN3-PhI(OAc)2 and -0.39 for IN3. On this basis a radical mechanism of the reaction was proposed.     

The heterocyclization of some reactive polymers by a 3 + 2 dipolar cyclo-addition reaction—II. Polyamides and polyhydrazides

Based on quantitative transformation of unsaturated polyesters into Δ₂-pyrazoline polymers when reacted with 1,3-dipoles, attempts were made to apply the same reaction to unsaturated polyamides and polyhydrazides having double bonds conjugated with a carbonyl group. One could not obtain heterocyclic polymers because of factors discussed in the paper. The presence of an active hydrogen atom in the molecule of polyamide or polyhydrazide causes a decrease of the dipolarophile capacity of the double bond. Substitution of these hydrogen atoms, both in model compounds and polymers, leads to the expected results. Thus N-alkylpolyamide was quantitatively transformed into the Δ₂-pyrazoline polyamide.     

Electron paramagnetic resonance and density-functional theory studies of Cu(II)-bis(oxamato) complexes

In this work we present the investigation of the influence of electronic and structural variations induced by varying the N,N'-bridge on the magnetic properties of Cu(II)- bis(oxamato) complexes. For this study the complexes [Cu(opba)] (2-) ( 1, opba = o-phenylene- bis(oxamato)), [Cu(nabo)] (2-) ( 2, nabo = 2,3-naphthalene- bis(oxamato)), [Cu(acbo)] (2-) ( 3, acbo = 2,3-anthrachinone- bis(oxamato)), [Cu(pba)] (2-) ( 4, pba = propylene- bis(oxamato)), [Cu(obbo)] (2-) ( 5, obbo = o-benzyl- bis(oxamato)), and [Cu(npbo)] (2-) ( 6, npbo = 1,8-naphthalene- bis(oxamato)), and the respective structurally isomorphic Ni(II) complexes ( 8- 13) have been prepared as ( (n)Bu 4N) (+) salts. The new complex ( (n)Bu 4N) 2[Cu(R-bnbo)].2H 2O ( 7, R-bnbo = (R)-1,1'-binaphthalene-2,2'- bis(oxamato)) was synthesized and is the first chiral complex in the series of Cu(II)-bis(oxamato) complexes. The molecular structure of 7 has been determined by single crystal X-ray analysis. The Cu(II) ions of the complexes 1- 7 are eta (4)(kappa (2) N, kappa (2) O) coordinated with a more or less distorted square planar geometry for 1- 6 and a distorted tetrahedral geometry for 7. Using pulsed Electron Nuclear Double Resonance on complex 6, detailed information about the relative orientation of the hyperfine ( A) and nuclear quadrupole tensors ( Q) of the coordinating nitrogens with respect to the g tensor were obtained. Electron Paramagnetic Resonance studies in the X, Q, and W-band at variable temperatures were carried out to extract g and A values of N ligands and Cu ion for 1- 7. The hyperfine values were interpreted in terms of spin population on the corresponding atoms. The obtained trends of the spin population for the monomeric building blocks were shown to correlate to the trends obtained in the dependence of the exchange interaction of the corresponding trinuclear complexes on their geometry.     

STUDIES ABOUT SYNTHESIS,CHARACTERIZATION, AND THE EFFECT OF 2-n-PROPYL-3-ETHYL-3-METHYL-1,4,2-BENZOXAZA-PHOSPHORINE-2-OXIDE ON GROWTH PARAMETERS AND CHLOROPHYLL CONTENT OF WHEAT

This article presents the synthesis and characterization of a new phosphorus heterocycle, namely 2-n-propyl-3-ethyl-3-methyl-1,4,2-benzoxaza-phosphorine-2-oxide, by a Mannich-type reaction between n-propyl-dichlorophosphine, methyl ethyl ketone, and o-aminophenol.

Taking into consideration that chlorophyll contents in plants were revealed to have connection with nitrogen and phosphorus concentrations at early growth stage, and because the above-mentioned heterocyclic compound can be considered as a phosphonic analogous of naturally occuring α-aminoacids, it was expected to develop biological activity from it. That is the reason why 2-n-propyl-3-ethyl-3-methyl-1,4,2-benzoxaza-phosphorine-2-oxide was subjected for biological tests on wheat.

The present study was also undertaken to investigate the interrelationship between chlorophyll content, dry matter, and other growth parameters of wheat, after treatment with different concentrations of 2-n-propyl-3-ethyl-3-methyl-1,4,2-benzoxaza-phosphorine-2-oxide.     

Influence of the preparation method on the surface characteristics and activity of boron-nitride-supported noble metal catalysts

In this article, we report how variations in the preparation method of boron-nitride-supported noble metal catalysts may influence the surface characteristics of the active phase and consequently the potential applications as catalysts for oxidation reactions. The deposition and the dispersion of the active phase are strongly influenced by the preparation process and in particular by the protic or aprotic solvent used as the dispersing phase; in this study, benzene, glyme, water, tetrahydrofuran, diglyme, 2-propanol, and glycol have been investigated. Characterization techniques, such as Brunauer-Emmett-Teller, X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis, have been used to study the influence of the choice of a solvent phase on the particle size and dispersion of the metal deposited on the BN support. The modifications undergone by the support during the deposition of palladium in different solvents have also been studied. Through the use of the same deposition procedure, different noble metal coatings (Pt, Pd, Au, and Ag) have been prepared. The acidic and redox characteristics of the resulting samples were characterized by temperature-programmed reduction and adsorption microcalorimetry. The catalytic performances of these materials were tested in the total oxidation of methane in lean conditions (excess oxygen and presence of water).     

<Emphasis Type="Italic">In vitro</Emphasis> hemocompatibility and corrosion behavior of new Zr-binary alloys in whole human blood

The aim of this study is to evaluate the accuracy of three binary alloys’ composition, and their biocompatibility. Depending on the intended use of the medical devices made from these materials, dynamic or static tests should be performed. We have chosen static tests as we thought they may be used as knee or hip replacement, and not as cardiac valves.Three binary alloys ( Zr10Nb, Zr2.5Nb and Zr12Ta) were obtained from high purity powders (>99.9%), using an induction furnace first, and an electric arc furnace for a perfect homogenization. Their final composition was verified with a XRF analyzer-INNOV-X.Hemolysis tests can determine the degree of red blood cells lysis and the release of hemoglobin. The released hemoglobin quantity was extremely small, under 2%, in all cases, and the coagulation tests showed no risk for thrombosis. The electrochemical behavior was also studied in biological fluid, human female serum, and showed a low corrosion rate.

The obtained alloys do not cause hemolysis, so they are hemocompatible with all blood types.

Open image in new window

     

Combustion synthesis of some iron oxides used as adsorbents for phenol and p-chlorophenol removal from wastewater

The effect of the fuel nature and of the reaction atmosphere (in air/in the absence of air) on the synthesis of iron oxides by the combustion method was investigated. Working in air, using urea with ammonium chloride as fuel, the final product of reaction is α-Fe₂O₃. Working in the absence of air, using oxalic, tartaric, respectively, citric acid as fuel, the single phase resulted in combustion reaction was Fe₃O₄. From the synthesized iron oxides investigated as potential sorbents for the removal of phenol and p-chlorophenol (PCP) from wastewater, only the sorbents obtained using tartaric acid as fuel (S3) and those obtained using citric acid as fuel (S2) show adsorption capacity for the two pollutants. The sorbent S3 shows better adsorption capacity for both phenol and for PCP compared with sorbent S2.     

Study of hydration and hardening processes of self-sensing cement-based materials with carbon black content

Journal of Thermal Analysis and Calorimetry - In this paper was assessed the influence of carbon black (CB) powder on the hydration and hardening processes of Portland cement (PC)-based materials;...     

Safe radical azidonation using polystyrene supported diazidoiodate(I)

Aldehydes are converted to acyl azides and benzyl ethers to azido ethers by treatment with polymer supported iodine azide in MeCN at 83 °C. The reaction provides a safe and convenient alternative to the use of iodine azide in radical azidonations.