bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and un-isotherm kinetic study of some ferrocene acids
Authors: Apreutesei Daniela , Lisa Gabriela , Hurduc Natalia , Scutaru Dan 
Published: August 2006

Abstract
The goal of this paper is to study thermal stability of some ferrocenes with acidic functional groups. Some other kinetic characteristics such as critical temperature and the rate constant corresponding to maximal degradation speed have been also evaluated. The type of functional units adjacent to the ferrocenyl unit determines thermal stability of ferrocene compounds. Groups with a powerful withdrawing effect determine a decreasing of the temperatures at which the material starts to lose weight. If a very long alkyl chain is connected to the ferrocene unit, a shielding effect in respect to the other carboxylic groups was observed, with an increase of the thermal stability.
HPLC monitored synthesis of R2NCH2 substituted benzene derivatives used as (C,N)-ligands for organometallic compounds
Authors: Soran Loredana , Coman Virginia , Soran Albert , Silvestru Cristian 
Published: August 2006

Abstract
2-(Diethylaminomethyl)phenyl bromide and 1,3-bis(dimethylaminomethyl)-benzene, useful ligands for the synthesis of hypervalent organometallic compounds, were prepared and characterized by NMR (1H, 13C, 2D experiments) spectroscopy. Their synthesis was monitored by the HPLC method. The compounds were eluted on a Nucleosil 120 Si column (5 μm, 25×0.4 cm) with n-hexane at room temperature using a 1.0 ml/min flow-rate. The maximum values of absorbance for the studied compounds, excepting the diethylamine, were located in a narrow range around 212 nm, the wavelength used for their UV detection. The diethylamine was detected at 190 nm. The calibration curves are straight lines with correlation factors r>0.995. The HPLC data are in good agreement with those provided by NMR spectroscopy.
A reducing-difference IR-spectral study of 4-aminopyridine
Authors: Arnaudov Michail , Ivanova Bojidarka , Dinkov Shishman 
Published: August 2006

Abstract
The IR-spectra of 4-aminopyridine (4-AP) in solution and in the solid state have been analyzed, using the reducing-difference procedure. Defining a more precise band assignment of a part of the characteristic frequencies of 4-AP, the data obtained proved in particular a Fermi-resonance splitting of the symmetric NH2-stretch.
Raman spectroscopic study of the hydration of short-chain poly(oxyethylene)s C 1EnC 1 (n=1−4)
Authors: Georgiev Mircho , Popova Tatiana , Nickolov Zhorro , Goutev Nikolay , Georgiev Georgi , Matsuura Hiroatsu 
Published: August 2006

Abstract
The hypothesis that the degree of hydration of poly(oxyethylene) (POE) in aqueous solution depends on the mole ratio of water molecules to ether oxygen atoms in the molecule has been verified by studying the isotropic Raman spectra in the O−H stretching region for four short-chain POEs (C 1EnC 1 withn=1−4). Excellent coincidence of the O−H stretching Raman band for all four POEs studied in the range of mole ratio H2O/Oether from 25 to 0.6 was observed, thus confirming the assumption stated above. A conclusion that all ether oxygen atoms in the POE molecule participate in hydrogen bonding with water molecules has been made.
Kinetic study of catalase adsorption on disperse carbonaceous matrices
Authors: Horozova Elena , Dimcheva Nina 
Published: August 2006

Abstract
The effect of the main factors known to govern the kinetic regularities of enzyme adsorption, such as enzyme solution concentration, temperature, pH, specific surface of the adsorbent, etc., were studied. Two kinds of disperse carbonaceous materials-activated carbon NORIT and carbon black PM-100, were used as matrices for enzyme immobilization. For both immobilization matrices studied, the amount of the adsorbed enzyme was found to reach saturation at catalase (CAT) enzyme concentrations exceeding 20 mg·mL−1 (∼100 μM). The pH of the solution affected the adsorption capacities of the selected immobilization matrices; larger amounts of CAT adsorbed were estimated in neutral and alkaline solutions than under acidic conditions for enzyme immobilization. UV-spectrophotometry was employed as a basic analytical approach in this study.
Physico-chemical properties of Chitosan films
Authors: Balau Luminita , Lisa Gabriela , Popa M. , Tura V. , Melnig V. 
Published: August 2006

Abstract
Chitosan films obtained by dry phase inversion were prepared from an aqueous solution of chitosan in acetic acid. The films, of thickness less than 20 μm, were transparent, very flexible and had smooth surfaces. Increasing the film thickness induced an increase of the internal tensions and the consequent formation of a rough surface. Structural investigations by X-ray diffraction and Fourier transform IR analysis, showed that the chitosan films, as prepared, are amorphous. Further annealing to evaporate acetic acid and water traces, changed the amorphous phase into a more ordered phase, characterized by diffraction peaks at 2θ values of 9, 17, 20 and 23 degrees. Thermal investigations by TG, DTG, and DTA revealed that the decomposition of the chitosan films as prepared proceeds in two stages, starting from 180°C and 540°C.
Kinetic and equilibrium study of the deprotonation of 4-nitrophenyl[bis(ethylsulphonyl)]methane by organic bases in acetonitrile in the presence of common cation BH+ and tetrabutylammonium perchlorate
Authors: Binkowska Iwona , Jarczewski Arnold 
Published: August 2006

Abstract
The results of kinetic and equilibrium experiments with the set of reaction of proton abstraction from 4-nitrophenyl[bis(ethylsulphonyl)]methane in acetonitrile are reported. Two strong organic bases are used: 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD).
The rates of proton transfer reaction have been measured by T-jump method in the presence of perchlorate of the appropriate base as a common cation BH+ and supporting electrolyte-tetrabutylammonium perchlorate (TBAP) in the temperature range between 20–40°C are: kH=1.32×107−2.00×107 and 2.82×107−4.84×107 dm 3mol−1s−1 for MTBD and TBD respectively. The enthalpies of activation ΔHMTBD≠=13.5 and ΔHTBD≠=18.1 kJmol−1. The entropies of activation are negative: ΔSMTBD≠=−62.3 and ΔSTBD≠=−40.3 Jmol−1K−1.
The change of the absorbance of the anion of 4-nitrophenyl[bis9ethylsulphonyl)]methane at the temperature 25°C in the presence of common cation BH+ gives the equilibrium constants K=705 and 906 M−1 for MTBD and TBD respectively.
Kinetic and equilibrium results are discussed. The possible mechanism of proton transfer reaction between 4-nitrophenyl[bis(ethylsulphonyl)]methane and cyclic organic bases: MTBD and TBD in acetonitrile is proposed.
Structural factors influencing the reaction rates of 4-aryloxy-7-nitrobenzofurazans with amino acids
Authors: Bem Marioara , Vasilescu Marilena , Caproiu Miron , Draghici Constantin , Beteringhe Adrian , Constantinescu Titus , Banciu Mircea , Balaban Alexandru 
Published: August 2006

Abstract
An interesting observation was made when studying the SNAr reaction between several 4-aryloxy-7-nitrobenzofurazans (2) and several amino acids leading to the apparition of detectable fluorescence from the substitution products3. Acidic amino acids reacted very slowly=while basic amino acids react fastest with2 having an unsubstituted phenyl or a 4-formyl-phenyl Ar group. Amongst neutral amino acids, proline reacts fastest at room temperature after 100 min. With2 having a methoxy-subtituted Ar group.
Radionuclides in deposition in the Ignalina NPP region in 2005
Authors: Jasiulionis Rimvydas , Rožkov Andrej 
Published: August 2006

Abstract
Results of radionuclide activity concentration measurements in deposition and ground-level air conducted at the station of the Institute of Physics situated 3.5 km from the Ignalina Nuclear Power Plant (Ignalina NPP) in 2005 are analyzed. Atmospheric depositional fluxes of 7Be, 60Co and 137Cs are estimated. Radionuclide particle deposition rates are calculated. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model of the global dispersion and deposition is used to explain variations in the 137Cs activity concentration in the ground-level air in the Ignalina NPP region in 2005. An increase in the 137Cs activity concentration of up to 17.4 µBq m−3 on 30 October-5 November is studied. Modelling results show that the Chernobyl NPP Unit 4 Sarcophagus and the radiocaesium resuspension from the Chernobyl NPP accident polluted regions are sources of 137Cs to the environment of the Ignalina NPP. Results on solubility in water of aerosols — carriers of 137Cs — are discussed.
A correlation between radiation sensitivity and initial chromatid breaks in cancer cell lines revealed by Calyculin A-induced premature condensation
Authors: Yang Jianshe , Jing Xigang , Wang Zhuanzi , Li Wenjian 
Published: August 2006

AbstractThree human malignancy cell lines were irradiated with 60Co γ-rays. Initial chromatid breaks were measured by using the chemically induced premature chromosome condensation technique. Survival curves of cells exposed to gamma rays was linear-quadratic while the efficiency of Calyculin A in inducing PCC of G2 PCC was about five times more than G1 PCC. A dose-dependent increase in radiation-induced chromatid/isochromatid breaks was observed in G1 and G2 phase PCC and a nearly positive linear correlation was found between cell survival and chromatin breaks. This study implies that low LET radiation-induced chromatid/isochromatid breaks can potentially be used to predict the radiosensitivity of tumor cells either in in vitro experimentation or in in vivo clinical radiotherapy.
Effect of Alpinia galanga extract on cartilage degradation and on gene expression in human chondrocyte and synovial fibroblast metabolism
Authors: Pothacharoen Peraphan , Choocheep Kanyamas , Pitak Tanyaluck , Pompimon Wilart , Premanode Bhusana , Hardingham Timothy , Kongtawelert Prachya 
Published: August 2006

AbstractWe investigated the effects of A. galanga extract on metabolism and gene expression involved in the interleukin-1β (IL-1β) response of human chondrocyte and synovial fibroblast. A. galanga extract inhibited IL-1β enhanced matrix breakdown of the cartilage explants in a dose-dependent manner. It suppressed uronic acid loss from the tissue and decreased the release of sulfated GAG and hyaluronan into the medium. MMP-2 and MMP-9 activity in the culture medium of chondrosarcomas and synovial fibroblasts were significantly reduced in the presence of A. galanga extract, which also suppressed the production of MMP-1,-3 and-13. The A. galanga extract also significantly increased type II collagen, SOX9 and aggrecan gene expression, suggesting an ability to enhance anabolic activity. At a high dose of A. galanga extract there was a down-regulation of aggrecan gene expression. Comparison with Diacerein® showed its general anti-inflammatory potential to be similar. The A. galanga extract was shown to inhibit IL-1β-stimulated cartilage matrix degradation in both systems. Additionally, the extract showed the potential to up-regulate certain chondrocyte anabolic genes. It may, therefore, offer some cartilage protective and anti-inflammatory properties as a therapeutic agent in arthritis.
Xenobiotics with estrogen or antiandrogen action — disruptors of the male reproductive system
Authors: Słowikowska-Hilczer Jolanta 
Published: August 2006

Abstract
The environmental and life-style changes associated with developing industry and agriculture, especially the exposure to endocrine disrupting chemicals (xenobiotics), are considered as causes of the increasing incidence of male reproductive system disorders. Most of the xenobiotics, which harmfully influence the male reproductive system, reveal estrogen-like (xenoestrogens) or anti-androgenic activity. Recent data have revealed physiological roles of estrogens in the male, however, there are evidences that estrogen-like substances may lead to many undesirable symptoms in the male i.e. gonadal dysgenesis, genital malformations, cryptorchidism, decreased fertility potential and testicular neoplastic changes. The number of xenoestrogens is still growing in the environment, whereas the mechanisms of their action are still not exactly known. They can be harmful not only to the present but potentially also to the next generations.
Disseminated extramedullary myeloid tumor of the gallbladder without involvement of the bone marrow
Authors: Bartley Angela N. , Nelson Craig L. , Nelson Donald H. , Fuchs Deborah A. 
Published: August 2006

AbstractExtramedullary myeloid tumors (myeloid sarcomas) are rare neoplasms that are composed of myeloid precursors. They usually arise concurrently with a diagnosis of acute myeloid leukemia, chronic myeloid leukemia, or other myeloproliferative disorders. They may also indicate relapsing disease in a patient with a prior history of leukemia or myeloproliferative disorder. We present our findings of a 63‐year‐old female diagnosed with extramedullary myeloid tumor first presenting in the gallbladder. She subsequently developed respiratory failure; pre‐ and postmortem bone marrow studies were negative for leukemia by morphology, flow cytometry, and karyotypic analysis. However, the myeloid neoplasm was disseminated throughout most of her remaining organs. Immunohistochemical stains of the cells indicated a neoplasm of myelomonocytic derivation (CD4, CD43, CD45, CD68, myeloperoxidase, and lysozyme positive). To our knowledge, this is the first report of an extramedullary myeloid neoplasm of the gallbladder with disseminated disease without involvement of the bone marrow. Am. J. Hematol., 2006. © Wiley‐Liss, Inc.
Preclinical assessment of curcumin as a potential therapy for B‐CLL
Authors: Everett Peter C. , Meyers John A. , Makkinje Anthony , Rabbi Mohammed , Lerner Adam 
Published: August 2006

AbstractCurcumin, the principle component of the spice turmeric, has been used as an anti‐inflammatory medication in India and China for centuries. Recent studies, predominantly using actively dividing cell lines, have suggested that this compound could be used as a chemopreventative or therapeutic agent for epithelial tumors. As curcumin has been reported to inhibit the NIK/IKK complex, an activity that would be expected to induce apoptosis in B cell malignancies, we sought to determine whether curcumin induces apoptosis in vitro in primary chronic lymphocytic leukemia (B‐CLL) cells. Primary leukemic cells were incubated with varying dosages of curcumin, followed by assessment for apoptosis. The role of PPARγ or NF‐κB signaling in curcumin‐induced apoptosis was examined by cotreatment with a PPARγ antagonist or EMSA of nuclear NFκB complexes. We also examined whether a clinically achievable concentration of curcumin (1 μM) would augment the apoptotic effects of fludarabine, dexamethasone, vincristine or the PDE4 inhibitor rolipram. In B‐CLL cells from 14 patients, curcumin‐induced apoptosis with a mean EC50 of 5.5 μM. In contrast, the EC50 for whole mononuclear cells from a healthy donor was 21.8 μM. In a 48 hr wash‐out time course, curcumin‐induced apoptosis was time‐dependent, with a substantial reduction in apoptosis observed when curcumin was removed after 5 hr. Curcumin treatment reduced basal nuclear NF‐κB levels and 1 μM curcumin augmented both vinca alkaloid and PDE4 inhibitor‐induced apoptosis in B‐CLL cells. Our studies suggest that curcumin may augment the efficacy of established or experimental therapies for B‐CLL. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Acute myeloid leukemia with T‐cell receptor gamma gene rearrangement occurring in a patient with chronic lymphocytic leukemia: A case report
Authors: Hatoum Hassan A. , Mahfouz Rami A.R. , Otrock Zaher K. , Hudaib Abdel‐Rahman , Taher Ali T. , Shamseddine Ali I. 
Published: August 2006

AbstractThe association of chronic lymphocytic leukemia (CLL) and acute leukemia, either lymphoid or myeloid is a rare event. Our review of the medical literature revealed only 6 cases of CLL transformation to acute myeloid leukemia (AML) (M0, M1 and M2) with no other associated malignancy. We report a similar case but with occurrence of AML‐M4 associated with normal cytogenetic analysis and molecular testing but with positive T‐cell receptor gamma gene rearrangement rather than the usual Vbeta rearrangement. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Function of interleukin‐20 as a proinflammatory molecule in rheumatoid and experimental arthritis
Authors: Hsu Yu‐Hsiang , Li Hsing‐Hui , Hsieh Mei‐Yi , Liu Ming‐Fei , Huang Kuo‐Yuan , Chin Lin‐Show , Chen Pei‐Chih , Cheng He‐Hsiung , Chang Ming‐Shi 
Published: August 2006

AbstractObjectiveThe pathogenesis of rheumatoid arthritis (RA) reflects an ongoing imbalance between proinflammatory and antiinflammatory cytokines. Interleukin‐20 (IL‐20) has proinflammatory properties for keratinocytes. In this study, we sought to determine whether IL‐20 is involved in RA.MethodsWe analyzed IL‐20 levels in synovial fluid from RA patients. IL‐20 and its receptors were detected in RA synovial fibroblasts (RASFs), using immunohistochemical staining. The effect of IL‐20 on endothelial cells, neutrophils, and RASFs was investigated using MTT and migration assays. The expression of IL‐20 and its receptors in healthy rats and in rats with collagen‐induced arthritis (CIA) was also analyzed. Soluble IL‐20 receptor type I (sIL‐20RI) or sIL‐20RII was administered to rats with CIA by intramuscular electroporation, and the severity of arthritis was monitored.ResultsRA patients expressed significantly higher levels of synovial fluid IL‐20 than did the rheumatic disease controls. IL‐20 and its receptors were expressed in the synovial membranes and RASFs. IL‐20 induced RASFs to secrete monocyte chemoattractant protein 1, IL‐6, and IL‐8, and it promoted neutrophil chemotaxis, RASF migration, and endothelial cell proliferation. Both IL‐20 and IL‐20RI were up‐regulated in the rat CIA model. In vivo, electroporated sIL‐20RI plasmid DNA decreased the severity of arthritis in the rats with CIA.ConclusionIL‐20 was up‐regulated in the synovial fluid of RA patients and acted as a chemokine that attracted the migration of neutrophils and RASFs in vitro. The rat CIA model demonstrated that IL‐20 was involved in the pathogenesis of arthritis, because sIL‐20RI significantly reduced arthritis in rats with CIA. Thus, IL‐20 may modulate the incidence and severity of arthritis and play important roles at local sites of inflammation.
Pathogenesis of osteoarthritis‐like changes in the joints of mice deficient in type IX collagen
Authors: Hu K. , Xu L. , Cao L. , Flahiff C. M. , Brussiau J. , Ho K. , Setton L. A. , Youn I. , Guilak F. , Olsen B. R. , Li Y. 
Published: August 2006

AbstractObjectiveTo examine the pathogenetic mechanisms of osteoarthritis (OA)–like changes in Col9a1−/− mice, which are deficient in type IX collagen.MethodsKnee joints and temporomandibular joints (TMJs) from Col9a1−/− mice and their wild‐type (Col9a1+/+) littermates were examined by light microscopy. Immunohistochemical staining was performed to examine the expression of matrix metalloproteinase 3 (MMP‐3) and MMP‐13, degraded type II collagen, and the discoidin domain receptor 2 (DDR‐2) in knee joints. Cartilage mechanics were also evaluated for compressive properties by microindentation testing of the tibial plateau and for tensile properties by osmotic loading of the femoral condyle.ResultsHistologic analysis showed age‐dependent OA‐like changes in the knee and TMJs of Col9a1−/− mice starting at the age of 3 months. At the age of 6 months, enhanced proteoglycan degradation was observed in the articular cartilage of the knee and TMJs of the mutant mice. The expression of MMP‐13 and DDR‐2 protein and the amount of degraded type II collagen were higher in the knee joints of Col9a1−/− mice than in their wild‐type littermates at the age of 6 months. Changes in cartilage mechanics were observed in the femoral and tibial plateaus of Col9a1−/− mice at 6 months, including a decrease in the compressive modulus and uniaxial modulus. At 3 and 6 months of age, tibial cartilage in Col9a1−/− mice was found to be more permeable to fluid flow, with an associated compromise in the fluid pressurization mechanism of load support. All of these changes occurred only at medial sites.ConclusionLack of type IX collagen in Col9a1−/− mice results in age‐dependent OA‐like changes in the knee joints and TMJs.
Increase in production of matrix metalloproteinase 13 by human articular chondrocytes due to stimulation with S100A4: Role of the receptor for advanced glycation end products
Authors: Yammani Raghunatha R. , Carlson Cathy S. , Bresnick Anne R. , Loeser Richard F. 
Published: August 2006

AbstractObjectiveS100 proteins have been implicated in various inflammatory conditions, including arthritis. The aims of this study were to determine whether chondrocytes produce S100A4 and whether S100A4 can stimulate the production of matrix metalloproteinase 13 (MMP‐13) by articular chondrocytes via receptor for advanced glycation end products (RAGE)–mediated signaling.MethodsThe expression of chondrocyte S100A4 was analyzed by immunohistochemistry using normal and osteoarthritic (OA) cartilage and by immunoblotting of chondrocyte cell lysates. RAGE signaling was examined by stimulating chondrocytes with S100A4 and monitoring for the activation of MAP kinases and NF‐κB. Production of MMP‐13 was determined in the conditioned medium. A pulldown assay using biotin‐labeled S100A4 was used to demonstrate binding to RAGE.ResultsS100A4 expression was detected in human articular chondrocytes by immunoblotting and appeared to increase in the cell lysates from OA tissue. Marked positive immunostaining for S100A4 was also noted in sections of human cartilage with changes due to OA. Stimulation of chondrocytes with S100A4 increased the phosphorylation of Pyk‐2, MAP kinases, and activated NF‐κB, followed by increased production of MMP‐13 in the conditioned medium. This signaling was inhibited in cells pretreated with soluble RAGE, advanced glycation end product–bovine serum albumin, or the antioxidant Mn(III)tetrakis (4‐benzoic acid) porphyrin, or by overexpression of a dominant‐negative RAGE construct. A pulldown assay showed that S100A4 binds to RAGE in chondrocytes.ConclusionThis is the first study to demonstrate that S100A4 binds to RAGE and stimulates a RAGE‐mediated signaling cascade, leading to increased production of MMP‐13. Since both S100A4 and RAGE are up‐regulated in OA cartilage, this signaling pathway could contribute to cartilage degradation in OA.