bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lidocaine/Monoethylglycinexylidide Test, Galactose Elimination Test, and Sorbitol Elimination Test for Metabolic Assessment of Liver Cell Bioreactors
Authors: Gerlach Jörg C. , Brayfield Candace , Puhl Gero , Borneman Reiner , Müller Christian , Schmelzer Eva , Zeilinger Katrin 
Published: April 2010

AbstractVarious metabolic tests were compared for the performance characterization of a liver cell bioreactor as a routine function assessment of cultures in a standby for patient application in clinical studies. Everyday quality assessment (QA) is essential to ensure a continuous level of cellular functional capacity in the development of hepatic progenitor cell expansion systems providing cells for regenerative medicine research; it is also of interest to meet safety requirements in bioartificial extracorporeal liver support systems under clinical evaluation. Quality criteria for the description of bioreactor cultures were developed using primary porcine liver cells as a model. Porcine liver cells isolated by collagenase perfusion with an average of 3 × 109 primary cells were used in 39 bioreactors for culture periods up to 33 days. Measurements of monoethylglycinexylidide synthesis and elimination of lidocaine, galactose elimination, and sorbitol elimination proved to be useful for routine QA of primary liver cell cultures. We demonstrate two methods for dispensing test substances, bolus administration and continuous, steady‐state administration. Bolus test data were grouped in Standard, Therapy, Infection/Contamination, and Cell‐free control groups. Statistical analyses show significant differences among all groups for every test substance. Post hoc comparisons indicated significant differences between Standard and Cell‐free groups for all elimination parameters. For continuous tests, results were categorized according to number of culture days and time‐dependent changes were analyzed. Continuous administration enables a better view of culture health and the time dependency of cellular function, whereas bolus administration is more flexible. Both procedures can be used to define cell function. Assessment of cellular function and bioreactor quality can contribute significantly to the quality of experimental or clinical studies in the field of hepatic bioreactor development.
Enhanced Bone Bonding of the Hydroxyapatite/β‐Tricalcium Phosphate Composite by Electrical Polarization in Rabbit Long Bone
Authors: Sagawa Hideki , Itoh Soichiro , Wang Wei , Yamashita Kimihiro 
Published: April 2010

AbstractA review of the osteogenic cell activity and new bone growth in the regions bordering negatively charged surfaces of polarized Hydroxyapatite/β‐tricalcium phosphate (HA/TCP) composites implanted in the long bone in rabbits was conducted. Polarized and non‐polarized HA/TCP specimens were implanted into the right and left femoral condyle, respectively (each n = 10). After 3 and 6 weeks, five rabbits were sacrificed in each group, and histological analysis was administered. Large cuboidal‐shaped osteoblastic cells were predominantly observed lining the newly formed bone on the negatively charged surface (N‐surface) in the polarized HA/TCP implants. The TRAP‐positive multinucleated cells were observed extensively in the newly formed bone on the N‐surfaces compared with the 0‐surface and adhered directly to the HA/TCP composite. The bone area (B.Ar) value, newly formed bone area contacting the implant, and contact length (C.Le) value, percentage length of newly formed bone directly attaching to the implant, on both the 0‐ and N‐surface increased significantly with time in each group. Both the B.Ar and C.Le value on the N‐surface were significantly greater than those on the 0‐surface after 3 and 6 weeks. The number of TRAP‐positive cells/total length value on the N‐surface was significantly greater than that on the 0‐surface after 3 and 6 weeks postoperatively. It is hypothesized that electrical charge acquired by electrical polarization treatment may modify the biochemical and biophysical processes of the osteogenic cells, resulting in enhanced new bone formation and direct bonding between the recipient bone and implants.
Plasmapheresis Does Not Affect Polysomnographic Parameters in Patients With Myasthenia Gravis: A Case Series Study
Authors: Yeh Jiann‐Horng , Chen Wei‐Hung , Chiu Hou‐Chang , Lee Chien‐Te , Hsu Chung‐Yao 
Published: April 2010

AbstractThe purpose of this study was to evaluate the influence of plasmapheresis on sleep in patients with generalized myasthenia gravis and no respiratory symptoms. Seven myasthenia gravis patients, four women and three men, aged 24–52 years, underwent plasmapheresis treatment because of recent worsening of clinical weakness and poor response to previous treatments. We prospectively recorded the myasthenia gravis score, measured acetylcholine‐receptor antibody concentration, performed polysomnography, and checked the Epworth Sleepiness Scale at baseline and 1 day after completion of the last session of plasmapheresis. Myasthenic weakness was ameliorated following plasmapheresis in all patients with a median decrease in myasthenia gravis score of 2 points (P = 0.0002) and a median clearance of 43.3% of acetylcholine‐receptor antibody. However, there was no significant change in polysomnographic parameters, except for a trend toward shorter duration of the longest apnea period (P = 0.0763) following the treatment. Plasmapheresis did not affect polysomnographic parameters despite improved clinical weakness along with decreased myasthenia gravis score and acetylcholine‐receptor antibody concentration.
Effects of Cyclic Stretch Waveform on Endothelial Cell Morphology Using Fractal Analysis
Authors: Haghighipour Nooshin , Tafazzoli‐Shadpour Mohammad , Shokrgozar Mohammad Ali , Amini Samira 
Published: April 2010

AbstractEndothelial cells are remodeled when subjected to cyclic loading. Previous in vitro studies have indicated that frequency, strain amplitude, and duration are determinants of endothelial cell morphology, when cells are subjected to cyclic strain. In addition to those parameters, the current study investigated the effects of strain waveform on morphology of cultured endothelial cells quantified by fractal and topological analyses. Cultured endothelial cells were subjected to cyclic stretch by a designed device, and cellular images before and after tests were obtained. Fractal and topological parameters were calculated by development of an image‐processing code. Tests were performed for different load waveforms. Results indicated cellular alignment by application of cyclic stretch. By alteration of load waveform, statistically significant differences between cell morphology of test groups were observed. Such differences are more prominent when load cycles are elevated. The endothelial cell remodeling was optimized when the applied cyclic load waveform was similar to blood pressure waveform. Effects of load waveform on cell morphology are influenced by alterations in load amplitude and frequency. It is concluded that load waveform is a determinant of endothelial morphology in addition to amplitude and frequency, and such effect is elevated by increase of load cycles. Due to high correlation between fractal and topological analyses, it is recommended that fractal analysis can be used as a proper method for evaluation of alteration in cell morphology and tissue structure caused by application of external stimuli such as mechanical loading.
Opaque Layer Firing Temperature and Aging Effect on the Flexural Strength of Ceramic Fused to Cobalt‐Chromium Alloy
Authors: De Vasconcellos Luis Gustavo Oliveira , Buso Leonardo , Lombardo Geraldo H. L. , Souza Rodrigo O. A. , Nogueira Júnior Lafayette , Bottino Marco Antonio , Özcan Mutlu 
Published: April 2010

Abstract Purpose: To evaluate the effect of the opaque layer firing temperature and mechanical and thermal cycling on the flexural strength of a ceramic fused to commercial cobalt‐chromium alloy (Co‐Cr). The hypotheses were that higher opaque layer temperatures increase the metal/ceramic bond strength and that aging reduces the bond strength. Materials and Methods: Metallic frameworks (25 × 3 × 0.5 mm3; ISO 9693) (N = 60) were cast in Co‐Cr and airborne‐particle abraded (Al2O3: 150 μm) at the central area of the frameworks (8 × 3 mm2) and divided into three groups (N = 20), according to the opaque layer firing temperature: Gr1 (control)—900°C; Gr2—950°C; Gr3—1000°C. The opaque ceramic (Opaque, Vita Zahnfabrick, Bad Säckingen, Germany) was applied, and the glass ceramic (Vita Omega 900, Vita Zahnfabrick) was fired onto it (thickness: 1 mm). While half the specimens from each group were randomly tested without aging (water storage: 37°C/24 hours), the other half were mechanically loaded (20,000 cycles; 50 N load; distilled water at 37°C) and thermocycled (3000 cycles; 5°C to 55°C, dwell time: 30 seconds). After the flexural strength test, failure types were noted. The data were analyzed using 2‐way ANOVA and Tukey's test (α= 0.05). Results: Gr2 (19.41 ± 5.5 N) and Gr3 (20.6 ± 5 N) presented higher values than Gr1 (13.3 ± 1.6 N) (p= 0.001). Mechanical and thermal cycling did not significantly influence the mean flexural strength values (p > 0.05). Increasing the opaque layer firing temperature improved the flexural bond strength values (p < 0.05). The hypotheses were partially accepted. Conclusion: Increasing of the opaque layer firing temperature improved the flexural bond strength between ceramic fused to Co‐Cr alloy.
A Simplified Technique for Creating a Customized Gingival Emergence Profile for Implant‐Supported Crowns
Authors: Azer Shereen S. 
Published: April 2010

AbstractA successful implant restoration is one that will allow adequate function and esthetics. Soft‐tissue management around implant‐supported restorations continues to present a considerable challenge for the restoring dentist as well as the laboratory technician while fabricating the final prosthesis. This article presents a simplified and economical technique to direct gingival tissue healing, as well as create a removable gingival replica of the customized gingival emergence profile. The created profile can then be used in the dental laboratory to achieve a superior and predictable esthetic outcome for implant‐supported fixed restorations.
9. Painful Shoulder Complaints
Authors: Huygen Frank , Patijn Jacob , Rohof Olav , Lataster Arno , Mekhail Nagy , Van Kleef Maarten , Van Zundert Jan 
Published: April 2010

AbstractPainful shoulder complaints have a high incidence and prevalence. The etiology is not always clear. Clinical history and the active and passive motion examination of the shoulder are the cornerstones of the diagnostic process. Three shoulder tests are important for the examination of shoulder complaints: shoulder abduction, shoulder external rotation, and horizontal shoulder adduction. These tests can guide the examiner to the correct diagnosis. Based on this diagnosis, in most cases, primarily a conservative treatment with nonsteroidal anti‐inflammatory drugs possibly in combination with manual and/or exercise therapy can be started. When conservative treatment fails, injection with local anesthetics and corticosteroids can be considered. In the case of frozen shoulder, a continuous cervical epidural infusion of local anesthetic and small doses of opioids or a pulsed radiofrequency treatment of the nervus suprascapularis can be considered.
Randomized Comparison of Multipolar, Duty‐Cycled, Bipolar‐Unipolar Radiofrequency Versus Conventional Catheter Ablation for Treatment of Common Atrial Flutter
Authors: ERDOGAN ALI , GUETTLER NORBERT , DOERR OLIVER , FRANZEN WOLFGANG , SOYDAN NEDIM , BILGIN MEHMET , VOGELSANG PASCAL , PARAHULEVA MARIANA , TILLMANNS HARALD , STRACKE SIEGBERT , GUENDUEZ DURSUN , NEUHOF CHRISTIANE 
Published: April 2010

Comparison of Radiofrequency Versus Conventional Catheter Ablation. Introduction: Radiofrequency (RF) catheter ablation has been established as an effective and curative treatment for atrial flutter (AFL). Approved methods include a drag‐and‐drop method, as well as a point‐by‐point ablation technique. The aim of this study was to compare the acute efficacy and procedural efficiency of a multipolar linear ablation catheter with simultaneous energy delivery to multiple catheter electrodes against conventional RF for treatment of AFL.
Methods:
Patients presenting to our department with symptomatic, typical AFL were enrolled consecutively and randomized to conventional RF ablation with an 8‐mm tip catheter (ConvRF) or a duty‐cycled, bipolar‐unipolar RF generator delivering power to a hexapolar tip‐versatile ablation catheter (T‐VAC) group. For both groups, the procedural endpoint was bidirectional cavotricuspid isthmus block.
Results:
Sixty patients were enrolled, 30 patients each assigned to ConvRF and T‐VAC groups. Total procedure time (40.2 ± 15.8 min vs 60.5 ± 12.7 min), energy delivery time (8.5 ± 3.7 min vs 14.7 ± 5.2 min), radiation dose (14.5 ± 3.5 cGy/cm2 vs 31.7 ± 12.1 cGy/cm2), and the minimum number of RF applications needed to achieve block (4.2 ± 2.4 vs 8.9 ± 7.2) were significantly lower in the T‐VAC group. In 7 patients treated with the T‐VAC catheter, bidirectional block was achieved with less than 3 RF applications, versus no patients with conventional RF energy delivery.
Conclusion:
The treatment of typical AFL using a hexapolar catheter with a multipolar, duty‐cycled, bipolar‐unipolar RF generator offers comparable effectiveness relative to conventional RF while providing improved procedural efficiency. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1109‐1113)
Assessing the distortionary impact of state trading in China
Authors: McCorriston Steve , MacLaren Donald 
Published: April 2010

AbstractState trading is a common feature in the management of imports and exports of agricultural products and it has been a long‐standing feature of China's agricultural trade regime. While the use of state trading was modified by China's accession to the WTO, it remains a dominant feature for some commodities, even though there have been recent attempts to diminish its importance. In this article, we review the role that the state trading enterprise (STE), China National Cereals, Oils and Foodstuffs Import and Export Company (COFCO), continues to play in the importing and exporting of some agricultural commodities. We then review the economic theory that has been developed to measure the tariff equivalent of importing STEs. Finally, we apply that theory through a calibration exercise to measure the tariff equivalent of COFCO in China's import market for wheat. The distortionary impact of COFCO depends on the bias in government policy toward agriculture, the competitiveness of the domestic procurement market, and also the number of firms that are allocated licenses to import alongside COFCO.
Spillovers from modern supply chains to traditional markets: product innovation and adoption by smallholders
Authors: Schipmann Christin , Qaim Matin 
Published: April 2010

AbstractThere is an emerging body of literature analyzing how smallholder farmers in developing countries can benefit from modern supply chains. However, most of the available studies concentrate on export markets and fail to capture spillover effects that modern supply chains may have on local markets. Here, we analyze the case of sweet pepper in Thailand, which was initially introduced as a product innovation in modern supply chains, but which is now widely traded also in more traditional markets. Using survey data from smallholder farmers and econometric techniques, we show that sweet pepper cultivation contributes significantly to higher household incomes. Strikingly, at this stage, participation in modern supply chains does not lead to higher incomes than supplying sweet pepper to traditional markets. However, the results also indicate that missing land titles, weak infrastructure conditions, and limited access to information constituted serious constraints during the early phases of sweet pepper adoption. Such constraints need to be overcome, so that smallholder farmers are better prepared for the prompt reactions needed under rapidly changing market conditions.
An econometric analysis of regional adoption patterns of Bt maize in Germany
Authors: Consmüller Nicola , Beckmann Volker , Petrick Martin 
Published: April 2010

AbstractIn this study, our goal is to identify and explain the underlying factors that drive regional adoption of Bt maize MON810 in Germany. Since regional differences cannot be explained by the occurrence of the target pest alone, we assume that under the given regulatory framework for genetically modified (GM) crop production in Germany, farm structures as well as the sociopolitical environment have also influenced regional adoption rates during the past years. Following a description of the relevant legal and economic framework in Germany, we develop theoretical hypotheses for regional variation in Bt maize adoption and test them econometrically with unique data at the federal state (Laender) and county (Landkreis) level. According to our analysis at the federal state level, the maize acreage per farm is the main driver of Bt maize adoption. In addition, there are signs that public opposition to GM cultivation as measured by membership in the German Friends of the Earth association significantly dampens GM cultivation. At the level of Brandenburg counties, the regional infestation frequency of the European Corn Borer, the target pest of Bt‐Maize, is the major determinant of adoption. Although Bt maize is a scale‐neutral technology for controlling damages caused by the Corn Borer, additional fixed costs due to regulation make the technology scale dependent.
Getting implicit shadow prices right for the estimation of the Malmquist index: the case of agricultural total factor productivity in developing countries
Authors: Nin‐Pratt Alejandro , Yu Bingxin 
Published: April 2010

AbstractThe Malmquist index has become extensively used in international comparisons of agricultural productivity since it does not require prices for its estimation, which are normally not available. However, the data envelopment analysis (DEA) approach used to estimate this index still uses implicit price information. This entails potential problems because these methods are susceptible to the effect of data noise, and shadow prices can prove to be inconsistent with prior knowledge on cost shares. In this article, we analyze implicit input shadow shares used in the DEA approach to estimate agricultural productivity using the Malmquist index for 63 developing countries. We then set bounds to the implicit input shares by introducing information on their likely value and compare constrained and unconstrained input shares. We conclude that the incidence of zero shadow prices justifies the introduction of constraints in the estimation of the Malmquist index. The article also presents detailed results of TFP growth in developing countries using constrained shadow shares for their estimation. We find that agricultural TFP has been growing steadily in the past 20 years even if countries like China, Brazil, and India are not considered. Remarkably, we find a clear improvement in the performance of Sub‐Saharan Africa since the mid 1980s.
Does heterogeneity in goals and preferences affect efficiency? A case study of farm households in northern Nigeria
Authors: Berkhout Ezra D. , Schipper Robert A. , Kuyvenhoven Arie , Coulibaly Ousmane 
Published: April 2010

AbstractHousehold characteristics are commonly used to explain variation in smallholder efficiency levels. The underlying assumption is that differences in intended behavior are well described by such variables, while there is no a priori reason that this is the case. Moreover, heterogeneity in farmer goals and preferences, in relation to the role of the farm enterprise, are not well documented in developing countries. This article makes a contribution to fill this gap, by empirically determining heterogeneity in farmer goals and attitudes in Nigeria through a pair‐wise ranking, supplemented with Likert scales. Factor analysis is used to reduce these data into behavioral factors. We estimate technical and allocative efficiency levels and analyze how these are related to farm characteristics and the identified behavioral factors. The models in which both intended behavior and farmer characteristics are included give a significantly better fit over models in which only household characteristics are included. These regression results suggest that the socioeconomic environment affects efficiency levels both directly and indirectly, through changes in goals and attitudes.
Productivity growth and the effects of R&D in African agriculture
Authors: Alene Arega D. 
Published: April 2010

AbstractThis article measures and compares total factor productivity growth in African agriculture under contemporaneous and sequential technology frontiers over the period 1970–2004. The sources of productivity growth are examined using a fixed‐effects regression model and a polynomial distributed lag structure for agricultural R&D expenditures. While conventional estimates show an average productivity growth rate of only 0.3% per year, the improved measures under sequential technology show that African agricultural productivity grew at a higher rate of 1.8% per year. Technical progress, rather than efficiency change, was the principal source of productivity growth. Agricultural R&D, weather, and trade reforms turned out to have significant effects on productivity in African agriculture. With a rate of return of 33% per year, R&D is shown to be a socially profitable investment in African agriculture. While a strong R&D expenditure growth of about 2% per year in the 1970s led to strong productivity growth after the mid 1980s, stagnation of R&D expenditure in the 1980s and early 1990s led to slower productivity growth in the 2000s. Consistent with recent economic recovery in Africa evidenced by stronger agricultural GDP growth rates, results showed that policy reforms as well as improved weather contributed to the recovery of agricultural productivity after the mid 1980s.
Influence of aquatic plant‐specific habitat on an assemblage of small neotropical floodplain fishes
Authors: Dibble E. D. , Pelicice F. M. 
Published: April 2010

Dibble ED, Pelicice FM. Influence of aquatic plant‐specific habitat on an assemblage of small neotropical floodplain fishes. Ecology of Freshwater Fish 2010: 19: 381–389. © 2010 John Wiley & Sons A/SAbstract –  This study investigated the effects of plant‐specific habitat on the distribution of young and small adult fishes in lagoons of the Upper Paraná River floodplain, Brazil. We compared fish catch per unit effort (CPUE) and species richness and used an indirect gradient analysis to investigate fish‐plant relationships within three aquatic macrophytes beds (Cabomba furcata, Eichhornia azurea, Nymphaea amazonum), and explored microhabitat influence (indexed by eight variables related to physical structure and water quality) on the structure of fish assemblages. Rarefaction analysis was used to compare fish species richness among the vegetated habitats. We captured a total of 1599 fish constituting 23 species, 7 families and 3 orders. Fish CPUE and species richness increased relative to microhabitat structure innate to the macrophytes; higher CPUE and richness were observed in C. furcata beds, a submerged aquatic macrophyte with finely dissected leaves. On the contrary, N. amazonum, a species that provides low microhabitat complexity, harbored fewer individual fish and number of species. Reproduction dynamics, hydrology and the amount of available plant‐generated habitat structure (surface effect) contributed to the disproportionally high number of individuals captured during the dry season. Our data suggest that the microhabitat physical structure (e.g., edge distance, stem density and patch size) provided by macrophyte beds in the lagoons of the Upper Paraná River may play a more important role than physicochemistry (e.g., oxygen, temperature and pH) at mediating distribution patterns of small‐sized fishes.