bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics and activation energy of the oxidation of para‐tolyl radical by cobalt(III) in acetic acid: Competition kinetics
Authors: Espenson James H. , Yiu Douglas Tak‐Yeung 
Published: August 2005

AbstractThe title reaction gives rise to a benzylic cation that is rapidly transformed to its bromide in competition with the reaction of the radical with carbon tetrachloride. Experiments were carried out over 17–69°C in acetic acid containing cobalt(II) acetate, para‐xylene, hydrobromic acid, carbon tetrachloride, and meta‐chloroperoxybenzoic acid. The product ratio, ArCH2Cl/ArCH2Br, in combination with other pertinent rate constants, was used to determine the rate constant for the step of interest: log k (L mol−1 s−1 = 19.9 – (75 ± 11 kJ mol−1/2.303 RT). The large pre‐exponential factor, which gives ΔS‡ = 128 J K−1 mol−1, signals an unusual transition state, because a negative value of ΔS‡ would be expected for a simple bimolecular reaction. The production of the ion pair ArCH‖OAc− in HOAc, which has the same dielectric constant as benzene, may be responsible, at least in part. Furthermore, inner sphere reorganization of cobalt may also contribute. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 599–604, 2005
Synthesis of Macroporous PMMA/Silica Nanocomposite Monoliths in Supercritical Carbon Dioxide
Authors: Yue Baohua , Yang Jun , Huang Chien‐Yueh , Dave Rajesh , Pfeffer Robert 
Published: August 2005

AbstractSummary: Macroporous monoliths consisting of silica nanoparticles embedded in poly(methyl methacrylate) (PMMA) were synthesized in supercritical CO2. Well‐dispersed silica particles, pretreated with functional 3‐(trimethoxysilyl)propyl methacrylate (MPS), were to form colloidal PMMA nanocomposites followed by a sol‐gel transition forming interconnected structures resulting in micron‐sized pores with specific areas between 1 and 7 m2 · g−1. SEM and TEM results revealed uniform morphological characteristics of the composite materials and good dispersions of the silica nanoparticles.SEM micrograph of PMMA/Silica nanocomposites forming interconnected macroporous monolith. The average size of the silica particles is 50 nm.imageSEM micrograph of PMMA/Silica nanocomposites forming interconnected macroporous monolith. The average size of the silica particles is 50 nm.
Surface‐Initiated Atom Transfer Radical Polymerization of Oligo(ethylene glycol) Methacrylate: Effect of Solvent on Graft Density
Authors: Feng Wei , Chen Renxu , Brash John L. , Zhu Shiping 
Published: August 2005

AbstractSummary: Oligo(ethylene glycol) methacrylate (OEGMA) was grafted from silicon wafer surfaces by surface‐initiated atom transfer radical polymerization (ATRP) with CuIBr/2,2′‐bipyridine (bpy) as a catalyst and various water/alcohol mixtures as solvents. The ellipsometric thickness of the poly(OEGMA) layer on the surface increased linearly with monomer conversion in solution. High graft densities were achieved in alcohols. The graft density of poly(OEGMA) in methanol was found to be 0.26 chains · nm−2, which is 50% higher than that in water/methanol (30:70, v/v). The differences in graft density were correlated to the conformation of tethered poly(OEGMA) chains. Large poly(OEGMA) coils on the surface in the presence of water limited the access of initiation sites to the catalyst complex and monomer molecules.Development of poly(OEGMA) layer thickness on the silicon surface vs monomer conversion.imageDevelopment of poly(OEGMA) layer thickness on the silicon surface vs monomer conversion.
A Novel Approach to Processing High‐Performance Polymers that Exploits Entropically Driven Ring‐Opening Polymerization
Authors: Ben‐Haida Abderrazak , Colquhoun Howard M. , Hodge Philip , Stanford John L. 
Published: August 2005

AbstractSummary:Blends of the poly(ether sulfone) derived from 4,4′‐biphenol and 4,4′‐dichlorodiphenylsulfone (Radel‐R™) with its homologous macrocyclic oligomers show greatly lowered melt viscosities relative to that of the parent polymer, potentially enabling more facile production and fabrication of fiber‐reinforced composite materials. The macrocycles can then undergo entropically driven ring‐opening polymerization in situ. The required blends can be obtained easilyin one step, by carrying out polycondensations at concentrations lower than those usually used for polymer synthesis.Percentage of MCOs5in the product as a function of total monomer concentration.imagePercentage of MCOs5in the product as a function of total monomer concentration.
Multifunctional Stimuli Responsive ABC Terpolymers: From Three‐Compartment Micelles to Three‐Dimensional Network
Authors: Katsampas Ilias , Roiter Yuri , Minko Sergiy , Tsitsilianis Constantinos 
Published: August 2005

AbstractSummary: A highly asymmetric P2VP58‐PAA924‐PBMA48 double hydrophilic block terpolymer exhibits a rich phase behavior as a function of pH. In acidic media (pH 1) three compartment micelles with a positively charged outer corona are formed. At high pH, the above structure is transformed into a three‐dimensional transient network constituted of hydrophobic domains interconnected with negatively charged bridging chains (PAA chains). At even higher pH (14) the network is disrupted and finally exhibits a closed loop sol–gel–sol behavior.AFM images of P2VP58‐PAA924‐PBMA48 micellar self assemblies deposited on mica.imageAFM images of P2VP58‐PAA924‐PBMA48 micellar self assemblies deposited on mica.
Brain atrophy rates in Parkinson's disease with and without dementia using serial magnetic resonance imaging
Authors: Burton Emma J. , McKeith Ian G. , Burn David J. , O'Brien John T. 
Published: August 2005

AbstractIncreased rates of brain atrophy are seen in Alzheimer's disease, but whether rates are similarly increased in other dementias such as Parkinson's disease dementia (PDD) has not been well examined. We determined the rates of brain atrophy using serial magnetic resonance imaging (MRI) in PDD and compared this finding to rates seen in cognitively intact Parkinson's disease (PD) patients and age‐matched control subjects. Thirty‐one patients (PD = 18, PDD = 13) and 24 age‐matched controls underwent serial volumetric 1.5 T MRI scans, approximately 1 year apart. Baseline and repeat scans were registered and quantification of the brain boundary shift integral was used to determine whole‐brain atrophy rates. Rates of brain atrophy were significantly increased in PDD (1.12 ± 0.98%/year) compared to PD (0.31 ± 0.69%/year; P = 0.018) and control subjects (0.34 ± 0.76%/year; P = 0.015). There were no differences in atrophy rates between controls and PD (P = 0.79). No correlations between increased atrophy rates and age or dementia severity (Mini‐Mental State Examination score) were observed. Serial MRI may be a useful tool for monitoring disease progression in PDD and further studies should investigate its utility for early diagnosis. © 2005 Movement Disorder Society
Presence of an APOE4 allele results in significantly earlier onset of Parkinson's disease and a higher risk with dementia
Authors: Pankratz Nathan , Byder Lisa , Halter Cheryl , Rudolph Alice , Shults Clifford W. , Conneally P. Michael , Foroud Tatiana , Nichols William C. 
Published: August 2005

AbstractThe ε4 allele of the apolipoprotein E gene (APOE4) has been consistently associated with a greater risk of Alzheimer's disease (AD) as well as an earlier onset of AD. It is possible that APOE4 may also play a role in the etiology of other neurodegenerative disorders, such as Parkinson's disease (PD). APOE genotype, age of onset, disease duration, smoking history, and dementia status were collected for families with PD, yielding 324 Caucasian families with complete information. Logistic regression employing one individual per family and including age of onset and disease duration as covariates demonstrated a significantly increased risk of dementia for those individuals having inherited at least one ε4 allele (OR = 3.37; P = 0.002). Survival analyses also demonstrated a significantly earlier age of onset for those subjects with at least one ε4 allele (59.7 years) as compared with those homozygous for the more common ε3 allele (62.4 years; P = 0.009). Thus, consistent with previous studies, we find evidence that the presence of an ε4 allele results in significantly earlier onset of PD and a greater likelihood of dementia. It appears the similarities between PD and AD may be due to an overlap in the diseases' genetic etiology. © 2005 Movement Disorder Society
Quantitative determination of SH groups using 19F NMR spectroscopy and disulfide of 2,3,5,6‐tetrafluoro‐4‐mercaptobenzoic acid
Authors: Potapenko Dmitrii I. , Bagryanskaya Elena G. , Grigoriev Igor A. , Maksimov Aleksander M. , Reznikov Vladimir A. , Platonov Vyacheslav E. , Clanton Thomas L. , Khramtsov Valery V. 
Published: August 2005

AbstractA new method of measurement of thiol concentration by 19F NMR spectroscopy is developed. The method is based on the detection of products of the exchange reaction of thiols with a newly synthesized fluorinated disulfide, 2,3,5,6‐tetrafluoro‐4‐mercaptobenzoic acid (BSSB). A significant broadening of the 19F NMR signal of BSSB in the presence of thiols was observed and attributed to the exchange reaction between the parent disulfide and 2,3,5,6‐tetrafluoro‐4‐mercaptobenzoic acid. The rate constant for this reaction was found to be equal to (63 ± 11) × 103 M−1 s−1 at pH 7.0. The method was applied for the measurement of concentration of glutathione and albumin in rat blood. Copyright © 2005 John Wiley & Sons, Ltd.
High‐dose cyclophosphamide in refractory myasthenia gravis with MuSK antibodies
Authors: Lin Peter T. , Martin Beth A. , Weinacker Ann B. , So Yuen T. 
Published: August 2005

AbstractWe describe a 48‐year‐old woman with seronegative myasthenia gravis (MG) and high‐titer of anti‐MuSK antibody. She had severe bulbar and respiratory weakness with minimal limb weakness for 2 years. Her disease responded poorly to all the conventional immunosuppressive regimens. Treatment with immunoablative dose of cyclophosphamide led to dramatic and sustained remission of her symptoms. High‐dose cyclophosphamide is an effective alternative in patients with unusually refractory disease. Muscle Nerve, 2005
Neuroprotective adeno‐associated virus Bcl‐xL gene transfer in models of motor neuron disease
Authors: Garrity‐Moses Mary E. , Teng Qingshan , Liu James , Tanase Diana , Boulis Nicholas M. 
Published: August 2005

AbstractRecent work implicates excitotoxicity‐induced apoptosis as the mechanism triggering motor neuron death in amyotrophic lateral sclerosis (ALS). Our laboratory has previously utilized glutamate excitotoxicity in vitro to study this process. The present experiment tests whether overexpression of the gene for Bcl‐XL can inhibit excitotoxicity in this model system. To track Bcl‐XL expression, the gene for green fluorescent protein (GFP) was inserted in‐frame, upstream of the Bcl‐XL gene. The GFP‐Bcl‐XL gene was then cloned into an adeno‐associated viral (AAV2) vector. GFP expression in both SH‐SY5Y and embryonic day 15 (E15) motor neurons (MNs) peaked 48 hours after infection. Bcl‐XL expression in SH‐SY5Y cells significantly reduced terminal deoxy‐UTP nick‐end labeling (TUNEL)–positive cells and maintained cell density after glutamate exposure. Similarly, Bcl‐XL expression inhibited the development of TUNEL staining in E15 MNs and supported cell density after glutamate exposure. These findings suggest that AAV‐mediated expression of genes for antiapoptotic proteins may provide a means for ALS gene therapy. Muscle Nerve, 2005
Systemic administration of L‐arginine benefits mdx skeletal muscle function
Authors: Barton Elisabeth R. , Morris Linda , Kawana Masataka , Bish Lawrence T. , Toursel Thierry 
Published: August 2005

AbstractA major consequence of muscular dystrophy is that increased membrane fragility leads to high calcium influx and results in muscle degeneration and myonecrosis. Prior reports have demonstrated that increased nitric oxide production via L‐arginine treatment of normal and mdx mice resulted in increased expression of utrophin and increased activation of muscle satellite cells, which could ameliorate the dystrophic pathology. We delivered L‐arginine to normal and mdx mice, and examined muscles for any functional changes associated with its administration. Treated mdx muscles were less susceptible to contraction‐induced damage and exhibited a rightward shift of the force–frequency relationship. Immunoblotting revealed increases in utrophin and γ‐sarcoglycan in the treated muscles. There was also a decrease in Evans blue dye uptake, indicating a reduction in myonecrosis. However, there was no decrease in serum creatine kinase or the proportion of central nuclei, nor any improvement in specific force. Together, these results show that L‐arginine treatment can be beneficial to mdx muscle function, perhaps through a combination of enhanced calcium handling and increased utrophin, thereby decreasing muscle degeneration. Muscle Nerve, 2005
Improvement of the Polyimide Surface Wettability Using SiOx Films Deposited in a DECR Reactor from HMDSO/O2 Mixtures
Authors: Bellel Azzedine , Sahli Salah , Raynaud Patrice , Segui Yvan , Ziari Zahira , Eschaich David , Dennler Gilles 
Published: August 2005

AbstractSummary: Polyimide (PI) foils were coated with thin SiOx films for surface wettability improvement. The deposition was carried out in a microwave DECR (Distributed Electron Cyclotron Resonance) plasma reactor from a mixture of HMDSO/O2. During deposition, the PI substrate was located downstream, exposed to long‐lived reactive precursors and to VUV radiation (position I) or located again downstream but shielded from VUV radiation (position II). Deposition time was varied in order to observe different stages of the film growth. The surfaces of the deposited films were investigated by means of contact angle, atomic force microscopy (AFM) and X‐ray photoelectron spectroscopy (XPS) measurements. According to contact angle measurements, the coated PI surface became hydrophilic already at a thickness of about 2.8 nm and stayed nearly at the same level still for thicker coating. The plasma deposition of the ultra‐thin SiOx layer increased significantly the polar component of the surface energy from 9 to 53 mJ · m−2 and consequently enhanced the wettability of the material. The treated surfaces were only moderately affected after eight weeks storage time in air, indicating stable surface treatments. AFM images revealed that during deposition, the PI surface topography remains relatively smooth when coated in position I. However, for PI coated in position II, the surface roughness becomes more pronounced as thickness is increased. XPS analysis showed that VUV irradiation of the PI surface leads to the formation of a high proportion of polar species which enhance the wettability of the surface. Curve fitting of the Si2p peak showed that, as the film thickness increases, the deposited film becomes more oxidized.Surface roughness of 6.6 nm thick SiOx film (Rav = 1.8 nm, Rrms = 2.3 nm).magnified imageSurface roughness of 6.6 nm thick SiOx film (Rav = 1.8 nm, Rrms = 2.3 nm).
Prediction of herb–drug metabolic interactions: a simulation study
Authors: Zhou Shufeng , Huang Min , Xu Anlong , Yang Hongyuan , Duan Wei , Paxton James W. 
Published: August 2005

AbstractIn vitroandin vivostudies have indicated that the induction or inhibition of cytochrome P450 (CYP) is one of the major mechanisms for some clinically important pharmacokinetic herb–drug interactions. An attempt was made to simulate the effects of herbal preparation with single or multiple CYP‐inhibiting constituents on the area of the plasma concentration‐time curve (AUC) of coadministered drug that was either a low clearance drug by intravenous (i.v.) injection or a high clearance drug by oral route. Our simulation studies indicated that the expected increase (Rc) in the AUC of the coadministered drug by inhibiting herbal constituent(s) was dependent on the route of administration. For low clearance drug by i.v. injection,Rcwas generally determined by inhibition constant (Ki), unbound inhibitor concentration ([I]), hepatic fraction (fh), number of inhibitory herbal constituents (n) and metabolic pathway fraction in hepatic metabolism (fm), whileRcfor a high clearance drug by oral route,Rcwas determined byKi, [I], n andfm. By varying these parameters,Rcchanged accordingly. It appeared likely to predict a herb–drug metabolic interaction, if the inhibiting herbal constituents could be quantitatively determined. However, many herb‐ and drug‐related factors may cause difficulties with the prediction, and thusin vivoanimal and human studies are always necessary. Copyright © 2005 John Wiley & Sons, Ltd.
Antimalarial compounds from Kniphofia foliosa roots
Authors: Wube Abraham Abebe , Bucar Franz , Asres Kaleab , Gibbons Simon , Rattray Lauren , Croft Simon L 
Published: August 2005

AbstractDuring the course of screening Ethiopian medicinal plants for their antimalarial properties, it was found that the dichloromethane extract of the roots of Kniphofia foliosa Hochst. (Asphodelaceae), which have long been used in the traditional medicine of Ethiopia for the treatment of abdominal cramps and wound healing, displayed strong in vitro antiplasmodial activity against the chloroquine‐sensitive 3D7 strain of Plasmodium falciparum with an ED50 value of 3.8 µg/mL and weak cytotoxic activity against KB cells with an ED50 value of 35.2 µg/mL. Five compounds were isolated from the roots and evaluated for their in vitro antimalarial activity. Among the compounds tested, 10‐(chrysophanol‐7′‐yl)‐10‐(ξ)‐hydroxychrysopanol‐9‐anthrone and chryslandicin, showed a high inhibition of the growth of the malaria parasite, P. falciparum with ED50 values of 0.260 and 0.537 µg/mL, respectively, while the naphthalene derivative, 2‐acetyl‐1‐hydroxy‐8‐methoxy‐3‐methylnaphthalene, exhibited a less significant antimalarial activity with an ED50 value of 15.4 µg/mL. To compare the effect on the parasite with toxicity to mammalian cells, the cytotoxic activities of the isolated compounds against the KB cell line were evaluated and 10‐(chrysophanol‐7′‐yl)‐10‐(ξ)‐hydroxychrysopanol‐9‐anthrone and chryslandicin displayed very low toxicity with ED50 values of 104 and 90 µg/mL, respectively. This is the first report of the inhibition of the growth of P. falciparum by anthraquinone‐anthrone dimers and establishes them as a new class of potential antimalarial compounds with very little host cell toxicity. Copyright © 2005 John Wiley & Sons, Ltd.
Inhibitory effects of Ganoderma applanatum on rat lens aldose reductase and sorbitol accumulation in streptozotocin‐induced diabetic rat tissues
Authors: Jung Sang Hoon , Lee Yeon Sil , Shim Sang Hee , Lee Sanghyun , Shin Kuk Hyun , Kim Ju Sun , Kim Yeong Shik , Kang Sam Sik 
Published: August 2005

AbstractAldose reductase, the key enzyme of the polyol pathway, is known to play important roles in diabetic complications. Therefore, inhibitors of aldose reductase would be potential agents for the prevention of diabetic complications. To evaluate the inhibitory potential of aldose reductase from Ganoderma applanatum (Polyporaceae), methanol (MeOH) and water extracts were tested for their effects on rat lens aldose reductase (RLAR). The effects of both extracts on streptozotocin (STZ)‐induced diabetes in rats were also investigated. The MeOH extract exhibited a potent rat lens aldose reductase (RLAR) inhibition in vitro, and showed a significant inhibition, of not only serum glucose concentrations, but also of sorbitol accumulations in the lens, red blood cells (RBC) and sciatic nerves in STZ‐induced diabetic rats. Associated with a reduction in serum glucose concentration in STZ‐induced diabetic rats, this extract was found to cause a significant glucose tolerance effect. These results suggested that G. applanatum might possess constituents with antidiabetic and inhibitory effects on diabetic complications. Copyright © 2005 John Wiley & Sons, Ltd.
Evaluation of some medicinal plant extracts for antidiarrhoeal activity
Authors: Atta Attia H. , Mouneir Samar M. 
Published: August 2005

AbstractThe antidiarrhoeal effect of seven plant extracts namely: the aerial parts of Euphorbia paralias L. (EP), Bidens bipinnata L. (BB), Cynachum acutum L. (CyAc), Diplotaxis acris (Forssk.) Boiss (DA), Convolvulus fatmensis (CF) and Schouwia thebaica Webb (ST) and the leaves of Plantago major L. (PM), was evaluated on castor oil‐induced diarrhoea, gastrointestinal movement in rats (charcoal meal) and on the motility of duodenum isolated from freshly slaughtered rabbits. A significant antidiarrhoeal effect of the tested plant extracts against castor oil‐induced diarrhoea in rats was achieved by 200 and 400 mg/kg. The tested plant extracts decreased the gastrointestinal movement as indicated by the significantly (p < 0.05 to 0.001) decreased distance travelled by the charcoal meal. The large dose of the tested plant extracts was slightly more effective than the small one. The antidiarrhoeal effect was confirmed by the reported dose dependent inhibition of the motility of duodenum isolated from freshly slaughtered rabbits. The EP and PM methanol extract produced a transient stimulation followed by inhibition in doses of less than 0.05 and 1.6 mg/kg, respectively. Higher concentrations caused rapid muscle relaxation. Tannins, flavonoids, unsaturated sterols/triterpenes, carbohyd‐rates, lactones and proteins/amino acids were reported as major active constituents of the tested plants. Copyright © 2005 John Wiley & Sons, Ltd.
Photoprotection by topical application of Achyrocline satureioides (‘Marcela’)
Authors: Morquio Andrea , Rivera‐Megret Felicia , Dajas Federico 
Published: August 2005

AbstractIt has been demonstrated that the use of topical antioxidants can contribute to controling the free radicals excess produced by ultraviolet (UV) irradiation of the skin, being beneficial for processes such as photo aging and eventually cancer. Some plant extracts, particularly because of their polyphenolic constituents, can be beneficial for skin photo damage.Plant extracts of Achyrocline satureioides (AS) and Epilobium parviflorum (EP), potent antioxidant medicinal plants, were mixed with a cosmetic base and applied to the back skin of rabbits. Afterwards the skin was exposed to 1 h of UV irradiation from a known source. The production of the hydroxyl (OH·) radical was assessed in the skin after UV by measuring 2,3‐dyhydroxybenzoic acid (2,3‐DHBA), produced by the hydroxylation of sodium salicylate, previously injected intracutaneously (i.c.) in the irradiated areas.The UV provoked a marked increase in 2,3‐DHBA that was significantly decreased by the AS cosmetic preparation. The EP extract did not show any effect on 2,3‐DHBA production. It is concluded that the cosmetic preparation containing the AS extract is able to scavenge OH production likely to be due to the presence of high concentrations of flavonoid aglycones such as quercetin, luteolin and 3‐O‐methylquercetin. Copyright © 2005 John Wiley & Sons, Ltd.
Radioprotective effect of sugar cane extract in chickens
Authors: Amer Said , Na Ki‐Jeong , Motobu Maki , El‐Abasy Moshira , Nakamura Kikuyasu , Koge Kenji , Hirota Yoshikazu 
Published: August 2005

AbstractTo evaluate the radioprotective effect of sugar cane extract (SCE), SCE was orally administered into the crop of 3‐week‐old chickens for 3 consecutive days before or after x‐ray radiation at a dose of 500 mg/kg/day. The survival rate of SCE administered chickens before x‐ray radiation at a dose of 920 rad increased to 68.8% when compared with that of the irradiated control (50%). Histopathological examination revealed the intestine of SCE administered chickens to have mild to moderate pathological changes, when compared with that of the irradiated control animals. Copyright © 2005 John Wiley & Sons, Ltd.