bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retrospective database analysis on the effectiveness of typical and atypical antipsychotic drugs in an outpatient clinic setting
Authors: Akkaya Cengiz , Sarandol Asli , Cangur Sengul , Kirli Selcuk 
Published: September 2007

AbstractObjectiveTo report the outcomes of a retrospective database analysis to compare the effectiveness of atypical and typical antipsychotic drugs.MethodsMedical records of patients admitted to the psychiatry outpatient clinic between January 1998 and October 2005 were retrospectively reviewed. Data obtained from patient records were noted on a special form assessing four aspects of the treatment history: socio‐demographic features, disease characteristics, initial treatment at the time of admission, and course of treatment. Patient groups (typical/atypical and Risperidone/Haloperidol/Olanzapine) were compared for time to all‐cause medication discontinuation and rate of discontinuation.ResultsThere was no statistically significant difference in the duration of treatment between patients using atypical (n = 150) and typical (n = 124) antipsychotics. The duration of treatment was significantly longer in patients on Haloperidol (n = 91) compared with those on Risperidone (n = 63). Rates of discontinuation over 18 months were 59.3% for patients on atypical antipsychotics and 57.3% for those on typical antipsychotics, and 68.3% for patients on Risperidone, 51.6% for patients on Haloperidol and 54.3% for patients on Olanzapine.ConclusionDespite our hypothesis patients with chronic schizophrenia discontinued their atypical and typical antipsychotics, at a high rate with no significant difference indicating substantial limitations in the effectiveness of these drugs. Copyright © 2007 John Wiley & Sons, Ltd.
Characteristics of chemistry and stable isotopes in groundwater of Chaobai and Yongding River basin, North China Plain
Authors: Aji K. , Tang C. , Song X. , Kondoh A. , Sakura Y. , Yu J. , Kaneko S. 
Published: September 2007

AbstractTo identify the groundwater flow system in the North China Plain, the chemical and stable isotopes of the groundwater and surface water were analysed along the Chaobai River and Yongding River basin. According to the field survey, the study area in the North China Plain was classified hydrogeologically into three parts: mountain, piedmont alluvial fan and lowland areas.The change of electrical conductance and pH values coincided with groundwater flow from mountain to lowland areas. The following groundwater types are recognized: CaHCO3 and CaMgHCO3 in mountain areas, CaMgHCO3 and NaKHCO3 in piedmont alluvial fan areas, and HCO3Na in lowland areas.The stable isotope distribution of groundwater in the study area also has a good corresponding relation with other chemical characteristics. Stable isotope signatures reveal a major recharge from precipitation and surface water in the mountain areas. Chemical and stable isotope analysis data suggest that mountain and piedmont alluvial fan areas were the major recharge zones and the lowland areas belong to the main discharge zone. Precipitation and surface water were the major sources for groundwater in the North China Plain. Stable isotopic enrichment of groundwater near the dam area in front of the piedmont alluvial fan areas shows that the dam water infiltrated to the ground after evaporation.As a result, from the stable isotope analysis, isotope value of groundwater tends to deplete from sea level (horizontal ground surface) to both top of the mountain and the bottom of the lowland areas in symmetrically. This suggests that groundwater in the study area is controlled by the altitude effect. Shallow groundwater in the study area belongs to the local flow system and deep groundwater part of the regional flow system. Copyright © 2007 John Wiley & Sons, Ltd.
Changes and variation in the discharge regime of the Upper Suriname River Basin and its relationship with the tropical Pacific and Atlantic SST anomalies
Authors: Nurmohamed Riad , Naipal Sieuwnath , Becker Cor 
Published: September 2007

AbstractLong‐term changes and variability in river flows in the tropical Upper Suriname River Basin in Suriname (2–6°N, 54–58°W) are analysed, including the relation to sea surface temperatures (SSTs) in the tropical Atlantic and Pacific Ocean. To analyse variability, lag correlation and statistical properties of the data series are used. Long‐term changes are analysed using parametric and non‐parametric statistical techniques. The analyses are performed for the period 1952–1985. The results show that both river discharge series at Semoisie and Pokigron are non‐stationary and have a negative trend. The negative rainfall trend in the centre of Suriname may be responsible for the negative trend in the annual river discharges in the basin. The highest correlation (Pearson's coefficient c) is obtained when the Tropical North Atlantic (TNA) SSTs lags the monthly discharges at Pokigron by 3–4 months (c = 0·7) and when the Tropical South Atlantic (TSA) SSTs lags the discharges by 4 months (c = − 0·7). It also follows that the high (low) monthly flows, from April–August (September–March) are associated with increasing (decreasing) SSTs in the TNA and with decreasing (increasing) SSTs in the TSA. The results also reveal that years with low (high) discharges are more related to warmer (colder) SSTs during the year in the TNA region and a southward displacement of the Inter‐Tropical Convergence Zone (ITCZ). However, the Pacific El Niño (La Niña) events may also be responsible for low (high) flow years in this basin. Copyright © 2007 John Wiley & Sons, Ltd.
Suspended sediment dynamics at high and low storm flows in two small watersheds
Authors: Salant Nira L. , Hassan Marwan A. , Alonso Carlos V. 
Published: September 2007

AbstractA record spanning almost 20 years of suspended sediment and discharge measurements on two reaches of an agricultural watershed is used to assess the influence of in‐channel sediment supplies and bed composition on suspended sediment concentrations (SSC). We analyse discharge‐SSC relationships from two small streams of similar hydrology, climate and land use but widely different bed compositions (one dominated by sand, the other by gravel). Given that sand‐dominated systems have more fine sediment available for transport, we use bed composition and the relative proportion of surface sand and gravel to be representative of in‐channel sediment supply. Both high flow events and lower flows associated with onset and late recessional storm flow (‘low flows’) are analysed in order to distinguish external from in‐channel sources of sediment and to assess the relationship between low flows and sediment supply. We find that SSC during low flows is affected by changes to sediment supply, not just discharge capacity, indicated by the variation in the discharge‐SSC relationship both within and between low flows. Results also demonstrate that suspended sediment and discharge dynamics differ between reaches; high bed sand fractions provide a steady supply of sediment that is quickly replenished, resulting in more frequent sediment‐mobilizing low flow and relatively constant SSC between floods. In contrast, SSC of a gravel‐dominated reach vary widely between events, with high SSC generally associated with only one or two high‐flow events. Results lend support to the idea that fine sediment is both more available and more easily transported from sand‐dominated streambeds, especially during low flows, providing evidence that bed composition and in‐channel sediment supplies may play important roles in the mobilization and transport of fine sediment. In addition, the analysis of low‐flow conditions, an approach unique to this study, provides insight into alternative and potentially significant factors that control fine sediment dynamics. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of the calcium to phosphate ratio of tetracalcium phosphate on the properties of calcium phosphate bone cement
Authors: Burguera Elena F. , Guitian Francisco , Chow Laurence C. 
Published: September 2007

AbstractSix different tetracalcium phosphate (TTCP) products were synthesized by solid state reaction at high temperature by varying the overall calcium to phosphate ratio of the synthesis mixture. The objective was to evaluate the effect of the calcium to phosphate ratio on a TTCP‐dicalcium phosphate dihydrate (DCPD) cement. The resulting six TTCP‐DCPD cement mixtures were characterized using X‐ray diffraction analysis, scanning electron microscopy, and pH measurements. Setting times and compressive strength (CS) were also measured. Using the TTCP product with a Ca/P ratio of 2.0 resulted in low strength values (25.61 MPa) when distilled water was used as the setting liquid, even though conversion to hydroxyapatite was not prevented, as confirmed by X‐ray diffraction. The suspected CaO presence in this TTCP may have affected the cohesiveness of the cement mixture but not the cement setting reaction, however no direct evidence of CaO presence was found. Lower Ca/P ratio products yielded cements with CS values ranging from 46.7 MPa for Ca/P ratio of 1.90 to 38.32 MPa for Ca/P ratio of 1.85. When a dilute sodium phosphate solution was used as the setting liquid, CS values were 15.3% lower than those obtained with water as the setting liquid. Setting times ranged from 18 to 22 min when water was the cement liquid and from 7 to 8 min when sodium phosphate solution was used, and the calcium to phosphate ratio did not have a marked effect on this property. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Investigation on clotting and hemolysis characteristics of heparin‐immobilized polyether sulfones biomembrane
Authors: Hou Changjun , Yuan Quan , Huo Danqun , Zheng Shujia , Zhan Dongli 
Published: September 2007

AbstractIn this study, a novel heparin‐immobilized polyethersulfone (PES) was synthesized. PES was initially sulfonated with chlorosulfonic acid and then 1,6‐hexanediamine was grafted to the SO3H groups of sulfonated PES, which subsequently reacted with heparin through a covalent bond by using (1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide hydrochloride (EDAC) as catalyst. The hydrophobic/hydrophilic property was characterized by measuring the water contact angle. The data shows decline from 62.29° ± 1.2° to 47.86° ± 0.3° for water and 86.79° ± 0.8° to 68.34° ± 1.0° for glycerol, which indicates an enhancement of hydrophilicity. Plasma hemolysis assay shows a comparatively low hemolysis ratio of 1.04%, which is below permissible limit of 5%. A higher content of dissociated blood cells and Ca2+ concentration was found in red blood cell counting and coagulation factor IV test in heparinized PES. Plasma recalcification time of 360 s also offers positive evidence that heparinized PES seems to have a good anticoagulation property. This new heparin‐immobilized PES biomaterials may have the potential for biomedical applications. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Quantitative spatial distribution of sirolimus and polymers in drug‐eluting stents using confocal Raman microscopy
Authors: Balss K.M. , Llanos G. , Papandreou G. , Maryanoff C.A. 
Published: September 2007

AbstractRaman spectroscopy was used to differentiate each component found in the CYPHER® Sirolimus‐eluting Coronary Stent. The unique spectral features identified for each component were then used to develop three separate calibration curves to describe the solid phase distribution found on drug‐polymer coated stents. The calibration curves were obtained by analyzing confocal Raman spectral depth profiles from a set of 16 unique formulations of drug‐polymer coatings sprayed onto stents and planar substrates. The sirolimus model was linear from 0 to 100 wt % of drug. The individual polymer calibration curves for poly(ethylene‐co‐vinyl acetate) [PEVA] and poly(n‐butyl methacrylate) [PBMA] were also linear from 0 to 100 wt %. The calibration curves were tested on three independent drug‐polymer coated stents. The sirolimus calibration predicted the drug content within 1 wt % of the laboratory assay value. The polymer calibrations predicted the content within 7 wt % of the formulation solution content. Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectra from five formulations confirmed a linear response to changes in sirolimus and polymer content. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Assessment of silicone gel breast implant biodurability by NMR and EDS techniques
Authors: Taylor R. B. , Eldred D. E. , Kim G. , Curtis J. M. , Brandon H. J. , Klykken P. C. 
Published: September 2007

AbstractIn a study using explanted gel breast implants and appropriate nonimplanted controls, we examined silicone biodurability after long‐term implantation. Using NMR spectroscopy, as well as NMR relaxometry measurements (T2), no evidence of hydrolysis or other chemical degradation of the cross‐linked silicone matrix was observed in specimens from an early breast implant model (Cronin) explanted after 32 years in vivo or a more recent Silastic® II model after 13 years in vivo. In addition, no appreciable differences were seen in T2 relaxation times comparing explanted breast implants to suitably‐matched nonimplanted controls, further underscoring the biostability of the cross‐linked silicone shell and gel. Our T2 data and resultant interpretations differ from a 2004 report by the NMR lab at the University of Münster, highlighting the importance of suitable nonimplanted controls and sample preparation. Energy dispersive spectroscopy (EDS) was also performed, confirming the persistence of a fluorosilicone layer inside the elastomer shells of Silastic II implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Development of a novel endothelial cell‐seeded endovascular stent for intracranial aneurysm therapy
Authors: Zhu Wei , Tian Yanlong , Zhou Liang‐Fu , Wang Yang , Song Donglei , Mao Ying , Yang Guo‐Yuan 
Published: September 2007

AbstractThe metallic stent has been widely used in endovascular treatment of intracranial aneurysms and arterial stenosis. Endothelialization at the neck of the aneurysm or stenotic lesion after stent deployment plays a pivotal role in preventing aneurysm recurrence, as well as local thrombus formation and restenosis. To deliver autologous endothelial cells and to promote the endothelialization on the luminal wall of the parent artery, we established an endothelial cell‐seeded intracranial stent device. Endothelial cells were isolated from canine jugular vein and identified by FACS assay and immunohistochemistry. We demonstrated that the seeded endothelial cells formed a confluent endothelial layer on the stent's surface. After being brushed with 100 dyne/cm2of shear stress, we found that this endothelial layer remained intact for at least 48 h on the heparinized polymer coated stent, rather than the poly‐lactic‐acid coated stent (p< 0.05). The results suggest that an autologous endothelial cell‐seeded stent may be a feasible and optimal tool for endothelial delivery during stenting and may overcome some limitations of the traditional bare stent in the treatment of intracranial aneurysms and arterial stenosis. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Doxycycline sustained release from brushite cements for the treatment of periodontal diseases
Authors: Tamimi Faleh , Torres Jesús , Bettini Ruggero , Ruggera Francesca , Rueda Carmen , López‐Ponce Manuel , Lopez‐Cabarcos Enrique 
Published: September 2007

AbstractDoxycycline (DOXY) is a wide spectrum antibiotic used in the treatment of dental, periodontal, and bone infections. Brushite cements are calcium phosphate biomaterials especially interesting for bone regeneration processes. In this work, we describe the preparation of a brushite cement containing DOXY and the drug release from the cement. DOXY solutions were mixed with the cement powder and after a 50% burst release in the first 12 h, a slow and controlled release was achieved over 3.5 days. The release of DOXY hyclate was controlled by both, diffusion and Ca2+ interaction. Formation of DOXY‐Ca2+ chelates was detected in the cement structure using solid state fluorescence. The brushite cement loaded with DOXY hyclate had antibacterial activity against periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides frosthytus. This new biomaterial may be helpful for the treatment of periodontal diseases. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Prediction of protein loop conformations using multiscale modeling methods with physical energy scoring functions
Authors: Olson Mark A. , Feig Michael , Brooks Charles L. 
Published: September 2007

AbstractThis article examines ab initio methods for the prediction of protein loops by a computational strategy of multiscale conformational sampling and physical energy scoring functions. Our approach consists of initial sampling of loop conformations from lattice‐based low‐resolution models followed by refinement using all‐atom simulations. To allow enhanced conformational sampling, the replica exchange method was implemented. Physical energy functions based on CHARMM19 and CHARMM22 parameterizations with generalized Born (GB) solvent models were applied in scoring loop conformations extracted from the lattice simulations and, in the case of all‐atom simulations, the ensemble of conformations were generated and scored with these models. Predictions are reported for 25 loop segments, each eight residues long and taken from a diverse set of 22 protein structures. We find that the simulations generally sampled conformations with low global root‐mean‐square‐deviation (RMSD) for loop backbone coordinates from the known structures, whereas clustering conformations in RMSD space and scoring detected less favorable loop structures. Specifically, the lattice simulations sampled basins that exhibited an average global RMSD of 2.21 ± 1.42 Å, whereas clustering and scoring the loop conformations determined an RMSD of 3.72 ± 1.91 Å. Using CHARMM19/GB to refine the lattice conformations improved the sampling RMSD to 1.57 ± 0.98 Å and detection to 2.58 ± 1.48 Å. We found that further improvement could be gained from extending the upper temperature in the all‐atom refinement from 400 to 800 K, where the results typically yield a reduction of ∼ 1 Å or greater in the RMSD of the detected loop. Overall, CHARMM19 with a simple pairwise GB solvent model is more efficient at sampling low‐RMSD loop basins than CHARMM22 with a higher‐resolution modified analytical GB model; however, the latter simulation method provides a more accurate description of the all‐atom energy surface, yet demands a much greater computational cost. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Charge parameterization of the metal centers in cytochrome c oxidase
Authors: Johansson Mikael P. , Kaila Ville R. I. , Laakkonen Liisa 
Published: September 2007

AbstractReliable atomic point charges are of key importance for a correct description of the electrostatic interactions when performing classical, force field based simulations. Here, we present a systematic procedure for point charge derivation, based on quantum mechanical methodology suited for the systems at hand. A notable difference to previous procedures is to include an outer region around the actual system of interest. At the cost of increasing the system sizes, here up to 265 atoms, including the surroundings achieves near‐neutrality for the systems as well as structural stability, important factors for reliable charge distributions. In addition, the common problem of converting between CH bonds and CC bonds at the border vanishes. We apply the procedure to the four redox‐active metal centers of cytochrome c oxidase: CuA, haem a, haem a3, and CuB. Several relevant charge and ligand states are considered. Charges for two different force fields, CHARMM and AMBER, are presented. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Insertion of C50 into single‐walled carbon nanotubes: Selectivity in interwall spacing and C50 isomers
Authors: Zhou Zhen , Zhao Jijun , Schleyer Paul von Ragué , Chen Zhongfang 
Published: September 2007

AbstractThe structures and electronic properties of nanoscale “peapods,” i.e., C50 fullerenes inside single‐walled carbon nanotubes (SWCNTs), were computationally investigated by density functional theory (DFT). Both zigzag and armchair SWCNTs with diameters larger than 1.17 nm can encapsulate C50 fullerenes exothermically. Among the SWCNTs considered, (9,9) and (16,0) SWCNTs are the best sheaths for both D3 and D5h isomers of C50, corresponding to 0.32–0.34 nm tube‐C50 distances. The orientation of C50 inside nanotubes also affects the insertion energies, which depend on the actual tube‐fullerene distances. The insertion of D3 and D5h isomers of C50 is somewhat selective; the less stable D5h isomer can be encapsulated more favorably inside SWCNTs at same tube‐C50 spacing. Because of the weak tube‐C50 interaction, the geometric and electronic structures of the peapods do not change greatly for the most stable configurations, but the selectivity in the interwall spacing and isomer encapsulation can be useful in separating various carbon fullerenes and their isomers. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008
Evaluation of enzymatic hydrolysis of wheat straw pretreated by atmospheric glycerol autocatalysis
Authors: Sun Fubao , Chen Hongzhang 
Published: September 2007

AbstractBACKGROUND: Because ethanol organosolv pulping requires high pressure and is highly volatile, an atmospheric autocatalytic glycerol organosolv pretreatment process has been investigated. Enzymatic hydrolysis of wheat straw pretreated using this method was evaluated to explore a novel, economically competitive and environmentally friendly pretreatment technology for bioconversion of lignocellulosic biomass. The method also provides economical utilization of industrial glycerol, helping to cope with the challenge of the excess production of glycerol and to further defray the cost of biodiesel production.RESULTS: With preliminary optimization of the parameters in the pretreatment process, pretreatment performed at 240 °C for 4 h with the glycerol addition of 15 g g−1 dry feedstock and wash at 80 °C led to high recovery of cellulose (95%) and good removal of lignin (>70%), which formed, respectively, 80% and 10% of the pulp. The enzymatic hydrolysis of the pretreated wheat straw yielded 90% of theoretically achievable sugar after 24 h and 92% after 48 h.CONCLUSION: Atmospheric autocatalytic glycerol organosolv pretreatment removed significant amounts of hemicellulose and lignin without affecting good cellulose recovery. The proposed novel strategy increased the susceptible of wheat straw to enzyme attack and led to enzymatic hydrolysis that was comparable with that achieved using ethanol organosolv pretreatment. Copyright © 2007 Society of Chemical Industry