bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the chromatic spectrum of acyclic decompositions of graphs
Authors: Jamison Robert E. , Mendelsohn Eric 
Published: June 2007

AbstractIf G is any graph, a G‐decomposition of a host graph H = (V, E) is a partition of the edge set of H into subgraphs of H which are isomorphic to G. The chromatic index of a G‐decomposition is the minimum number of colors required to color the parts of the decomposition so that two parts which share a node get different colors. The G‐spectrum of H is the set of all chromatic indices taken on by G‐decompositions of H. If both S and T are trees, then the S‐spectrum of T consists of a single value which can be computed in polynomial time. On the other hand, for any fixed tree S, not a single edge, there is a unicyclic host whose S‐spectrum has two values, and if the host is allowed to be arbitrary, the S‐spectrum can take on arbitrarily many values. Moreover, deciding if an integer k is in the S‐spectrum of a general bipartite graph is NP‐hard. We show that if G has c > 1 components, then there is a host H whose G‐spectrum contains both 3 and 2c + 1. If G is a forest, then there is a tree T whose G‐spectrum contains both 2 and 2c. Furthermore, we determine the complete spectra of both paths and cycles with respect to matchings. © 2007 Wiley Periodicals, Inc. J Graph Theory 56: 83–104, 2007
GC‐MS analysis of multiply derivatized opioids in urine
Authors: Chen Bud‐Gen , Wang Sheng‐Meng , Liu Ray H. 
Published: June 2007

AbstractOpiates such as hydrocodone, hydromorphone, oxycodone, noroxycodone, and oxymorphone reportedly may interfere with the analysis of morphine and codeine. The analysis of these compounds themselves also is an important issue. Thus, double derivatization approaches utilizing methoxyamine and hydroxylamine to first form oxime products with keto‐opiates, followed by the derivatization with trimethylsilyl (TMS) or propionyl groups, have been developed for the simultaneous analysis of these compounds. However, these studies have not included all compounds of interest and resulted in inadequate chromatographic resolution or significant intensity cross‐contribution between the ions designating the analyte and its deuterated internal standard for certain compounds. By exploring three‐step derivatization approaches with the combination of various derivatization groups and orders, this study concluded that application of methoxyimino/propionyl/TMS groups, in the order listed, facilitated the simultaneous analysis of eight opiates (morphine, 6‐acetylmorphine, hydromorphone, oxymorphone, codeine, hydrocodone, oxycodone and noroxycodone) in urine samples, achieving satisfactory limits of quantitation and detection. In addition, the adapted approach resulted in two usable products for morphine and codeine providing alternatives, should interferences render any of these products non‐usable. Copyright © 2007 John Wiley & Sons, Ltd.
Impaired SDF1/CXCR4 signaling in glial progenitors derived from SOD1G93A mice
Authors: Luo Yongquan , Xue Haipeng , Pardo Andrea C. , Mattson Mark P. , Rao Mahendra S. , Maragakis Nicholas J. 
Published: June 2007

AbstractMutations in the superoxide dismutase 1 (SOD1) gene are associated with familial amyotrophic lateral sclerosis (ALS), and the SOD1G93A transgenic mouse has been widely used as one animal model for studies of this neurodegenerative disorder. Recently, several reports have shown that abnormalities in neuronal development in other models of neurodegeneration occur much earlier than previously thought. To study the role of mutant SOD1 in glial progenitor biology, we immortalized glial restricted precursors (GRIPs) derived from mouse E11.5 neural tubes of wild‐type and SOD1G93A mutant mice. Immunocytochemistry using cell lineage markers shows that these cell lines can be maintained as glial progenitors, because they continue to express A2B5, with very low levels of glial fibrillary acidic protein (astrocyte), βIII‐tubulin (neuron), and undetected GalC (oligodendrocyte) markers. RT‐PCR and immunoblot analyses indicate that the chemokine receptor CXCR4 is reduced in SOD1G93A GRIPs. Subsequently, SOD1G93A GRIPs are unable to respond to SDF1α to activate ERK1/2 enzymes and the transcription factor CREB. This may be one pathway leading to a reduction in SOD1G93A cell migration. These data indicate that the abnormalities in SOD1G93A glial progenitor expression of CXCR4 and its mediated signaling and function occur during spinal cord development and highlight nonneuronal (glial) abnormalities in this ALS model. © 2007 Wiley‐Liss, Inc.
Gender‐specific in vivo measurement of the structural and mechanical properties of the human patellar tendon
Authors: Onambélé Gladys N.L. , Burgess Katherine , Pearson Stephen J. 
Published: June 2007

AbstractHuman patellar tendon stress (σ), strain (ε), stiffness (K), and tensile or Young's modulus (E), are determined in vivo through voluntary isometric contractions monitored with B‐mode ultrasonography. The limitations in previous studies are: (1) they have generally not accounted for the fact that the distal attachment of the patellar tendon (the tibial tuberosity) also displaces; thus, they have underestimated ε (and, hence, injury risk) while overestimating K; (2) no gender effect has been studied despite the fact that females are seen to have higher incidences of tendon‐related injuries. The current investigation therefore aimed to determine the gender specific values of σ, ε, K, and E of the patellar tendon while also accounting for distal displacement of the patellar tendon. Healthy young males (aged 23.1 ± 1.3 years, n = 10) and females (aged 21.3 ±0.9 years, n = 10) were tested. The maximal ε of the young males was ∼5–10% higher than that reported in earlier literature. Average female versus male values for ε, σ, K, and E, taken at the same force level as the males for comparison purposes, were respectively 10.6 ± 1.0 versus 9.0 ± 1.0%, 36.9 ± 1.4 versus 28.9 ± 0.9 MPa, 1053 ± 108 versus 1652 ± 216 N · mm−1, and 0.61 ± 0.08 versus 0.68 ± 0.10 GPa (p < 0.05). There are gender differences in tendon structural and mechanical properties. The current methodology may be useful in a clinical context where early prediction of injury risk and/or monitoring of reconstructed tendon needs to be an accurate, objective, and reliable method if optimal functionality is to be achieved. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1635–1642, 2007
Gene expression of myogenic regulatory factors, nicotinic acetylcholine receptor subunits, and GAP‐43 in skeletal muscle following denervation in a rat model
Authors: Ma Jianjun , Shen Jian , Garrett Jeffrey P. , Lee Cassandra A. , Li Zhongyu , Elsaidi Gamal A. , Ritting Andrew , Hick Jeffrey , Tan Kim H. , Smith Thomas L. , Smith Beth P. , Koman L. Andrew 
Published: June 2007

AbstractNeuromuscular junction destabilization following nerve injury contributes to irreversible functional impairment. Myogenic Regulatory Factors (MRF's) including myoblast determination factor (MyoD), MRF‐4, Myogenin, and myogenic factors‐5 (myf‐5), and Growth‐associated protein 43 KDa (GAP43) regulate gene expression of nicotinic acetylcholine receptor (nAChR) subunits (alpha, beta, delta, gamma, and epsilon). We hypothesized that nerve injury induces altered gene expression of MRF's, nAChRs, and GAP‐43 in the skeletal muscle which destabilize neuromuscular junctions. The tibial nerve was transected in 42 juvenile male Sprague‐Dawley rats. Denervated and contralateral control gastrocnemius m. mRNA for nAChR subunits, MRF's, and GAP‐43 were determined by real time reverse transcription polymerase chain reaction (real time RT‐PCR). After transection, muscle mass decreased for 1 year with a nadir of 75% at 3 months. Alpha, gamma, and epsilon subunit genes increased by 3 and peaked at 7 days before returning to control levels (P < 0.05). Beta subunits and GAP‐43 tended to increase. Delta subunits peaked at 3 days returning to control levels by 30 days. By one month, most of the nAChR subunits had returned to control levels. Alpha, beta, gamma, and delta subunit expression remained significantly lower than control up to 1 year later (P < 0.05). MRF4, Myogenin, and MyoD expression paralleled that of alpha, gamma, and epsilon nAChR subunits (P < 0.05). Gene expression of nAChR alpha, gamma, delta and epsilon subunits was biphasic in the first month after nerve injury, similar to that of MRF's. nAChR subunits and MRF's may play a critical role in neuromuscular junction stability. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1498–1505, 2007
Role of parathyroid hormone in the mechanosensitivity of fracture healing
Authors: Gardner Michael J. , van der Meulen Marjolein C.H. , Carson Joshua , Zelken Jonathan , Ricciardi Benjamin F. , Wright Timothy M. , Lane Joseph M. , Bostrom Mathias P. 
Published: June 2007

AbstractThe mechanical environment at a fracture site can influence the course of healing. Intermittent parathyroid hormone (PTH) has been shown to accelerate fracture healing. Intact bone models show that mechanical loading and PTH have a synergistic beneficial effect on osteogenesis. We hypothesized that PTH and mechanical loading would have a similar synergistic effect on fracture healing. Eighty mice underwent surgical osteotomy and intramedullary nailing of the tibia. The mice were divided into four groups: one underwent daily loading, one received daily subcutaneous PTH injections (30 µg/kg/day), one received both loading and PTH, and a control group received sham loading and vehicle injection. Daily loading was applied to the ends of the tibia with an external loading device for 2 weeks. Fracture healing was assessed by microcomputed tomography, histology, and biomechanical testing. The group with both loading and PTH had increased osteoblast and osteoclast activity and was the only group with a significantly larger callus mineral density and bone volume fraction. The PTH only group had significantly more osteoid in the callus compared to the control group, indicating enhanced early osteoblast activity. This group also had a significantly higher bone mineral content and total bone volume compared to controls. The group that received loading as the only intervention had significantly greater osteoclast activity versus controls. The contribution of loading and PTH administration to the fracture healing cascade indicates a synergistic effect. This finding may be of potential clinical utility when weight bearing is utilized to stimulate lower extremity fracture healing. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1474–1480, 2007
Oxysterols enhance osteoblast differentiation in vitro and bone healing in vivo
Authors: Aghaloo Tara L. , Amantea Christopher M. , Cowan Catherine M. , Richardson Jennifer A. , Wu Ben M. , Parhami Farhad , Tetradis Sotirios 
Published: June 2007

AbstractOxysterols, naturally occurring cholesterol oxidation products, can induce osteoblast differentiation. Here, we investigated short‐term 22(S)‐hydroxycholesterol + 20(S)‐hydroxycholesterol (SS) exposure on osteoblastic differentiation of marrow stromal cells. We further explored oxysterol ability to promote bone healing in vivo. Osteogenic differentiation was assessed by alkaline phosphatase (ALP) activity, osteocalcin (OCN) mRNA expression, mineralization, and Runx2 DNA binding activity. To explore the effects of osteogenic oxysterols in vivo, we utilized the critical‐sized rat calvarial defect model. Poly(lactic‐co‐glycolic acid) (PLGA) scaffolds alone or coated with 140 ng (low dose) or 1400 ng (high dose) oxysterol cocktail were implanted into the defects. Rats were sacrificed at 6 weeks and examined by three‐dimensional (3D) microcomputed tomography (microCT). Bone volume (BV), total volume (TV), and BV/TV ratio were measured. Culture exposure to SS for 10 min significantly increased ALP activity after 4 days, while 2 h exposure significantly increased mineralization after 14 days. Four‐hour SS treatment increased OCN mRNA measured after 8 days and nuclear protein binding to an OSE2 site measured after 4 days. The calvarial defects showed slight bone healing in the control group. However, scaffolds adsorbed with low or high‐dose oxysterol cocktail significantly enhanced bone formation. Histologic examination confirmed bone formation in the defect sites grafted with oxysterol‐adsorbed scaffolds, compared to mostly fibrous tissue in control sites. Our results suggest that brief exposure to osteogenic oxysterols triggered events leading to osteoblastic cell differentiation and function in vitro and bone formation in vivo. These results identify oxysterols as potential agents in local and systemic enhancement of bone formation. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1488–1497, 2007
No effects of in vivo micro‐CT radiation on structural parameters and bone marrow cells in proximal tibia of wistar rats detected after eight weekly scans
Authors: Brouwers Julienne E.M. , van Rietbergen Bert , Huiskes Rik 
Published: June 2007

AbstractRecently developed in vivo animal high‐resolution micro‐CT scanners offer the possibility to monitor longitudinal changes in bone microstructure of small rodents, but may impose high radiation doses that could damage bone tissue. The goal of this study was to determine the effects on the bone of 8 weeks of in vivo scanning of the proximal tibia in female Wistar rats. Eight weekly CT scans were made of the right proximal tibia of nine female, 30‐week‐old, retired‐breeder, Wistar rats. Two weeks after the last weekly scan, a final scan was made. The left leg was only scanned during first and final measurements and served as a control. A two‐way ANOVA with repeated measures was performed on the first and last measurements of left and right tibiae for six bone structural parameters. Bone marrow cells were flushed out and tested for cell viability. No significant difference was found between left and right for any of the bone structural parameters (p > 0.05). Structure model index and trabecular separation significantly changed as a result of aging, while none of the other parameters did. No significant difference was found between left and right in absolute and percentage number of cell viability. We did not find any indication that the applied scanning regime, in combination with the particular settings used, would affect the results of in vivo bone structural measurements in long‐term studies using aged, female Wistar rats. However, careful consideration should be made when determining the number of scans, particularly when a different experimental design is used. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1325–1332, 2007
Hearth bread baking quality of durum wheat varying in protein composition and physical dough properties
Authors: Edwards Nancy M , Preston Ken R , Paulley F Garth , Gianibelli M Cristina , McCaig Tom N , Clarke John M , Ames Nancy P , Dexter James E 
Published: June 2007

AbstractThirty durum wheat genotypes from ten countries of origin were grown in field plots for two consecutive years. Three of the genotypes were γ‐gliadin 42 types and the remainder were γ‐gliadin 45 types. Among the γ‐gliadin 45 types, six high‐molecular‐weight glutenin subunit (HMW‐GS) patterns were identified: 6 + 8, 7 + 8, 7 + 16, 14 + 15, 20 and 2*, 20. All the γ‐gliadin 42 genotypes contained low amounts of unextractable polymeric protein (UPP) and exhibited low gluten index values and weak gluten properties. The γ‐gliadin 45 genotypes exhibited a wide range of UPP, gluten index and dough strength. HMW‐GS 20 genotypes were generally weak, whereas HMW‐GS 6 + 8 and 7 + 8 genotypes were generally strong. When baked by a lean formulation, long‐fermentation straight‐dough hearth bread process, the durum wheat genotypes exhibited a wide range of baking quality. Loaf volume and bread attributes were strongly correlated with UPP and gluten index. Some of the genotypes exhibited bread attributes and loaf volume equal or slightly superior to those of a high‐quality bread wheat flour. However, even the strongest durum wheat genotypes exhibited inferior fermentation tolerance to the bread wheat flour, as seen by a requirement for lower baking absorption during dough handling and more fragile dough properties when entering the oven. Among the HMW‐GS groups, HMW‐GS 7 + 8 and 6 + 8 exhibited the best and HMW‐GS 20 the poorest baking quality. Farinograph, alveograph and small‐scale extensigraph properties demonstrated that a combination of dough elasticity and extensibility was needed for superior durum wheat baking performance. Copyright © 2007 Society of Chemical Industry
Survival in patients with papillary thyroid cancer is not affected by the use of radioactive isotope
Authors: Podnos Yale D. , Smith David D. , Wagman Lawrence D. , Ellenhorn Joshua D.I. 
Published: June 2007

AbstractIntroductionPapillary cancer is the most common neoplasm of the thyroid. The mainstay of treatment is thyroidectomy, but most patients are additionally treated with radioactive iodine (RAI). Its utility is controversial. This study seeks to determine whether RAI use affects patient outcome and to identify specific cohorts of patients that benefit from its use.MethodsThe Surveillance, Epidemiology, and End Results (SEER) database is a large‐scale sample of approximately 14% of the US population. It was used to identify patients with papillary carcinoma of the thyroid. Statistical analyses were used to compare prognostic factors such as lymph node status, age, tumor size, and treatment with RAI.ResultsA total of 14,545 patients were identified in SEER as having papillary cancer of the thyroid. Multivariate analysis showed significantly worse outcome in patients with age>45 years, tumor size >2 cm, lymph node disease, and distant metastases. Multivariate analysis failed to show RAI significantly affecting mortality. Survival between those not treated with RAI was similar to those whose treatment included it (P = 0.9176). Subgroup analysis identified patients older than 45 years with primary tumors >2 cm and disease in the lymph nodes with distant metastatic disease as the only group positively affected by RAI.ConclusionsDespite its widespread use in the treatment of well‐differentiated papillary cancer of the thyroid, RAI only affects a survival advantage in older patients with large primary tumors involving the lymph nodes and with distant spread. Treating other patient groups is costly and offers no improvement in outcome. J. Surg. Oncol. 2007; 96:3–7. © 2007 Wiley‐Liss, Inc.
Photophysics and kinetics of naphthopyran derivatives, Part 5: An analytical model utilizing temperature effects to evaluate ABC(2k,3–5ϕ) kinetic parameters
Authors: Maafi M. , Brown R. G. 
Published: June 2007

AbstractA theoretical model is established for a photochemical ABC(2k,6ϕ) system in order to characterize the relationship of its absorbance at the photostationary state with temperature. Provided that the thermal processes of the system are not opposing steps, it has been found that depending on the relative magnitude of the system parameters (two rate constants, up to six quantum yields, and two extinction coefficients), several behaviors are predicted by the model. However, from an analytical viewpoint, this mathematical description generates for all cases, six new equations involving kinetic and spectroscopic parameters that are numerically defined by the available experimental data. For the first time, the latter are used to solve the dynamics of several systems. Novel procedures allowing a complete analytical elucidation of ABC(2k,3ϕ) systems (eight unknowns) as well as many other cases belonging to ABC(2k,4–5ϕ) kinetics have been successfully established. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 472–479, 2007
The silver(I)‐catalyzed exchange of coordinated cyanide in hexacyanoferrate(II) by phenylhydrazine in aqueous medium
Authors: Naik R. M. , Tiwari R. K. , Singh P. K. , Yadav S. B. S. 
Published: June 2007

AbstractThe [Ag]+‐catalyzed exchange of coordinated cyanide in [Fe(CN)6]4− by phenylhydrazine (PhNHNH2) has been studied spectrophotometrically at 488 nm by monitoring increase in the absorbance for the formation of cherry red colored complex [Fe(CN)5PhNHNH2]3−. The other reaction conditions were pH 2.80±,0.02, temperature = 30.0 ± 0.1°C, and ionic strength (I) = 0.02 M (KNO3). The reaction was followed as a function of pH, ionic strength, temperature, [Fe(CN)4−6], [PhNHNH2], [Ag+] by varying one variable at a time. The initial rates were evaluated for each variation using the plane mirror method. The initial rates evaluated as a function of [Fe(CN)4−6] clearly indicate that the initial rate increases with the increase in [Fe(CN)4−6] and finally reaches to a limiting value when [Fe(CN)4−6]/[AgNO3] ⩾ 1000. It indicates the formation of a strong adduct between [Fe(CN)6]4− and AgNO3 prior to the abstraction of CN−. The variation in initial rates with [PhNHNH2] also showed limiting values at [Fe(CN)4−6]/[PhNHNH2] ⩾ 8.30. The complex behavior due to pH and [Ag+] variations on the rate has been explained in detail. The composition of the final reaction product [Fe(CN)5PhNHNH2] formed during the course of reaction has been found to be 1:1 using the mole ratio method. The evaluated values of activation parameters for the catalyzed reaction are Ea = 53.85 kJ mol−1, Δ H≠, = 51.33 kJ mol−1, and Δ S≠ = −134.63 J K−1 mol−1, which suggest an interchange dissociative mechanism. A most plausible mechanistic scheme has been proposed based on the experimental observations. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 447–456, 2007
Kinetics and mechanism of oxidation of the drug mephenesin by bis(hydrogenperiodato)argentate(III) complex anion
Authors: Shen Shigang , Shi Hongmei , Sun Hanwen 
Published: June 2007

AbstractMephenesin is being used as a central‐acting skeletal muscle relaxant. Oxidation of mephenesin by bis(hydrogenperiodato)argentate(III) complex anion, [Ag(HIO6)2]5−, has been studied in aqueous alkaline medium. The major oxidation product of mephenesin has been identified as 3‐(2‐methylphenoxy)‐2‐ketone‐1‐propanol by mass spectrometry. An overall second‐order kinetics has been observed with first order in [Ag(III)] and [mephenesin]. The effects of [OH−] and periodate concentration on the observed second‐order rate constants k′ have been analyzed, and accordingly an empirical expression has been deduced: k′ = (ka + kb[OH−])K1/{f([OH−])[IO−4]tot + K1}, where [IO−4]tot denotes the total concentration of periodate, ka = (1.35 ± 0.14) × 10−2M−1s−1 and kb = 1.06 ± 0.01 M−2s−1 at 25.0°C, and ionic strength 0.30 M. Activation parameters associated with ka and kb have been calculated. A mechanism has been proposed to involve two pre‐equilibria, leading to formation of a periodato‐Ag(III)‐mephenesin complex. In the subsequent rate‐determining steps, this complex undergoes inner‐sphere electron transfer from the coordinated drug to the metal center by two paths: one path is independent of OH− whereas the other is facilitated by a hydroxide ion. In the appendix, detailed discussion on the structure of the Ag(III) complex, reactive species, as well as pre‐equilibrium regarding the oxidant is provided. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 440–446, 2007