bluuebunny/crossref_metadata_2025 huggingface dataset:
Osteoblasts Express Types I and II Activin Receptors During Early Intramembranous and Endochondral Bone Formation
Authors: Shuto Toshihide , Sarkar Gobinda , Bronk James T. , Matsui Nobuzo , Bolander Mark E.
Published: June 2006

Increasing evidence suggests a potential role for activin in bone formation. However, the cognate receptors through which activins function with respect to skeletal tissues have not yet been identified. Identification and regulation of expression of these receptors are necessary prerequisites to understanding the role of activins in bone metabolism. We detected mRNAs for three activin receptors, type I (ActRI), type II (ActRII), and type IIB (ActRIIB), in multiple skeletal tissues in rat, including tibia and costochondral growth plate, and also in cultured osteoblasts. To gain information about the relationship between receptor expression and different skeletal cell functions, we evaluated expression of the three receptors in a semiquantitative manner during the early stages of fracture healing, a model for rapid bone formation. Relatively high levels of ActRI and ActRII expression were detected in the callus at 7, 10, and 14 days after fracture, times that correlate with the interval of rapid intramembranous bone formation and the initiation of endochondral bone formation. Expression of the ActRIIB in the fracture callus was strikingly lower than either ActRI or ActRII. Immunostaining of the fracture callus and the newborn rat femur with an anti-ActRII antibody localized the receptor to osteoblasts at regions of membranous and endochondral bone formation. No staining of osteoblasts in fracture callus or bone was seen with an anti-ActRIIB antibody. These results provide strong evidence of the identification of the principal receptors through which activins could function in the skeletal system and further shed light on activin's mechanism of action in bone formation.
Humor and shyness: The relation between humor styles and shyness
Authors: Hampes William P
Published: June 2006

The Shyness Scale and Humor Styles Questionnaire were given to 174 subjects (69 male, 105 female). There was a significant negative correlation between shyness and affiliative humor for the total group, which was explained by the inability of shy people to relax enough in social situations to use this kind of humor. There was a significant positive correlation between shyness and self-defeating humor for the total group, a result that was expected due in large part to the low self-esteem of shy people. For the total group correlations between shyness and self-enhancing humor and between shyness and aggressive humor were not significant. Some of the sex differences between shy males versus shy females on aggressive and self-defeating humor were discussed.
Dolus eventualis und die dritte Schuldform
Authors: Papageorgiou-Gonatas Stylianos
Published: June 2006

Die Abgrenzungsfrage zwischen bewusster Fahrlässigkeit und bedingtem Vorsatz gehört zu den schwierigsten und umstrittensten Fragen in der Strafrechtsdogmatik. Sie hat jetzt in Griechenland eine besondere Bedeutung erlangt aufgrund der gesetzlichen Lage über den Dolus eventualis, die sich von der deutschen Rechtslage unterscheidet. Ausgelöst durch die aktuelle griechische Rechtsprechung innerhalb der letzten fünf Jahre zeigen sich neue Tendenzen für die Strafrechtswissenschaft, die von den traditionellen Theorien abzuweichen scheinen.
Effects of Particle Size and Shear Rate on Melt Flow Properties During Capillary Extrusion of Glass Bead-Filled LDPE Composites
Authors: Liang J-Z
Published: June 2006

The melt flow properties of a low-density polyethylene (LDPE) filled with glass brads (GB) were measured at 150°C by means a capillary rheometer to identify the effects of the particle size and extrusion rate on the melt flow behavior in the present paper. The volume fraction of the glass beads was 8.4 %. The surface of the particles had been treated with a silane-coupling agent and the diameter range was from 4 μm to 180 μm. The results showed that the entry pressure drop was a component function of apparent shear rate and the melt shear flow approximately obeyed the power law. The melt shear viscosity decreased roughly linearly with an increase of the wall shear stress, and it varied slightly with an addition of the bead diameter under various shear stress levels. Namely, the influence of the bead size on the melt flow properties of the LDPE/GB composites was insignificant at lower concentration of the fine spheres. This might be attributed to the relatively weak interfacial adhesion between the particles and the matrix due to the smooth spherical surface of the beads.
Comparison of Pond Production of Phase-III Sunshine Bass Fed 32-, 36-, and 40%-Crude-Protein Diets with Fixed Energy: Protein Ratios
Authors: Wetzel James E , Kasper Craig S , Kohler Christopher C
Published: June 2006

We stocked phase-III sunshine bass (white bass Morone chrysops ♀ × striped bass M. saxatilis ♂) at a rate of 6,188 fingerlings/ha into twelve 0.04-ha earthen ponds supplied with continuous aeration. Three dietary treatments were randomly assigned to quadruplicate ponds. Sunshine bass were fed to apparent satiation once daily after average initial weight (mean ± SE = 214 ± 5 g) and total length (245 ± 1.6 mm) were determined. Diets were formulated to conserve the estimated digestible energy : crude protein (CP) ratio (9.3 kcal/g protein) and represented the following CP and energy values fed to fish: 32% CP (3,000 kcal/kg), 36% CP (3,360 kcal/kg), and 40% CP (3,760 kcal/kg). Harvest data suggest that nutrient density is a variable that can be manipulated to optimize production and reduce production costs. Production rates (mean ± SE) were 2,851 ± 600 kg/ha for the 32%-CP diet, 2,895 ± 341 kg/ha for the 36%-CP diet, and 2,953 ± 142 kg/ha for the 40%-CP diet; production rates were not significantly different among dietary treatments. Survival was excellent and did not appear to be related to dietary treatment. Dressed (gilled and gutted) fish averaged 80% of whole-fish weight, and the dressed percentage did not vary as a function of nutrient density. Feed conversion ratios of 3.0 ± 0.4, 2.8 ± 0.2, and 2.6 ± 0.1 were obtained for the fish fed 32-, 36-, and 40%-CP diets, respectively. Protein conversion ratios (mean = 1.0) were not significantly influenced by dietary treatment. Feed cost increased with increasing dietary CP level; costs were US.447 per kilogram for the 32%-CP diet, .493 per kilogram for the 36%-CP diet, and .541 per kilogram for the 40%-CP diet. The resulting production costs attributable to feed were $1.34, $1.38, and $1.41 per kilogram of gain for the 32-, 36-, and 40%-CP diets, respectively. A savings of .16 per kilogram produced, or approximately $450 per hectare, was realized as a result of feeding either of the two lower-CP, lower-energy diets. Accordingly, we suggest that phase-III sunshine bass can be more economically produced by feeding diets as low as 32% CP with a minimum energy : protein ratio of 9.3 kcal/g CP.
Condition-based capital valuation of a road network
Authors: Snaith M. S. , Orr D. M.
Published: June 2006

The introduction of resource accounting for public assets in the United Kingdom and elsewhere has brought with it the need to determine the capital value of road networks, including the loss of value due to deterioration in service. Various methods have been proposed for this, some of which have depended on fairly simplistic and arguably inappropriate accountancy practices that are more appropriate for assets with a straight-line depreciation. However, roads are ideally retained in a good order to ensure satisfactory service to the travelling public. As a result of this, considerable work has been undertaken over the last few years to develop a practical way of determining the value of a road network based on its measured condition. This work is now accepted for use in Northern Ireland on non-trunk routes and has proved both useful and effective in operation. The basis for the calculations is presented in this paper.
Generalized Scaling Approach for Spontaneous Imbibition: An Analytical Model
Authors: Li Kewen , Horne Roland N.
Published: June 2006

Scaling the experimental data of spontaneous imbibition without serious limitations has been difficult. To this end, a general approach was developed to scale the experimental data of spontaneous imbibition for most systems (gas/liquid/rock and oil/water/ rock systems) in both cocurrent and countercurrent cases. We defined a dimensionless time with almost all the parameters considered. These include porosity, permeability, size, shape, boundary conditions, wetting- and nonwetting-phase relative permeabilities, interfacial tension (IFT), wettability, and gravity. The definition of the dimensionless time was not empirical; instead, it was based on theoretical analysis of the fluid-flow mechanisms that govern spontaneous imbibition. The general scaling method was confirmed against the experimental data from spontaneous water imbibition conducted at different IFTs in oil-saturated rocks with different sizes and permeabilities. A general analytical solution to the relationship between recovery and imbibition time for linear spontaneous imbibition was derived. The analytical solution predicts a linear correlation between the imbibition rate and the reciprocal of the recovery by spontaneous imbibition in most fluid/ fluid/rock systems.
Toe-To-Heel Waterflooding. Part ll: 3D Laboratory-Test Results
Authors: Turta Alex T. , Singhal Ashok K. , Goldman Jon , Zhao Litong
Published: June 2006

A new waterflooding process, toe-to-heel waterflooding (TTHW), was developed, based partly on a recently developed thermal TTH displacement process, TTH air injection (THAI). TTHW is a novel oil-recovery process that uses a horizontal producer (HP) and a vertical injector (VI). The HP has its horizontal leg located at the top of formation, while its toe is close to the VI, which is perforated at the lower part of the formation.

TTHW realizes a gravity-stable displacement, in which the water/oil mobility ratio becomes less important and its detrimental effect on sweep efficiency is diminished; the injected water always breaks through at the toe, after which water cut gradually increases.

A systematic investigation of the TTHW process in a Hele-Shaw laboratory model mimicking a simulated porous medium showed that the process substantially improved the vertical sweep efficiency as compared to conventional waterflooding. Following these semiquantitative tests, a more comprehensive 3D-model testing was undertaken to investigate the overall sweep efficiency of the process. The 3D model consists of a metal box filled with glass beads and saturated with oil at connate-water saturation. Oil was displaced with high-salinity brine, either in a TTH configuration or in a conventional array, using only vertical wells.

A staggered line drive was used by injecting water in two vertical wells located at one side of the box and producing oil by using either an HP with its toe close to the injection line or a vertical producer located at the HP's heel position.

Several TTHW tests were carried out at different injection rates. For a given injection rate, the TTHW results were compared to those of conventional-waterflooding tests. For the same amount of water injected, the ultimate oil recovery increased by a factor of up to 2, as compared to that for conventional waterflooding.

All in all, the results of these investigations show that the novel TTHW process is sound and can be optimized further.
Nitrogen Fixation and Transfer in a Mixed Stand of Alfalfa and Bermudagrass
Authors: Haby Vincent A. , Stout Stephen A. , Hons Frank M. , Leonard Allen T.
Published: June 2006

Information about dinitrogen (N2) fixation and transfer is needed to determine potential benefits from growing binary mixtures of alfalfa (Medicago sativa L.) and hybrid bermudagrass [Cynodon dactylon (L.) Pers.] on Coastal Plain soils of the USA. Our objectives were to quantify N2 fixed by alfalfa and transferred to bermudagrass. ‘Alfagraze’ alfalfa was grown at row spacings (RS) of 23, 46, 69, and 91 cm in a mixed stand with ‘Coastal’ bermudagrass on a Darco loamy fine sand (loamy siliceous, semiactive thermic Grossarenic Paleudult). The mixed stand was fertilized with 0, 28, 56, 84, and 112 kg N ha−1 applied for each bermudagrass regrowth. Isotope dilution was used to estimate N2 fixation and subsequent transfer to bermudagrass in the zero‐applied N plots. Wider alfalfa RS significantly increased bermudagrass yields. Higher N rate (NR) significantly improved bermudagrass yield during cool temperature and drought stress periods in 1994 and 1996. Narrower RS and higher NR significantly increased alfalfa production. Legume N derived from the atmosphere ranged from 42 to 91% and the fixed N yield ranged from 80 to 222 kg N ha−1 yr−1. Bermudagrass N derived from atmospheric N2 fixation ranged from 1.0 to 77%, and the transfer N yield (TNY) was ≤18 kg N ha−1 yr−1. Results varied depending on harvest date, year, treatment, and grass yield. Alfalfa RS had little effect on TNY. The low bermudagrass yield and subsequent TNY in this binary forage production system suggest that monoculture alfalfa may be the best approach for managing alfalfa on Coastal Plain soils.
Nitrogen Yield and Land Use Efficiency in Annual Sole Crops and Intercrops
Authors: Szumigalski Anthony R. , Van Acker Rene C.
Published: June 2006

Nitrogen is the most limiting nutrient for crop production on the northern Great Plains of North America. This study was initiated to determine if N yield and land use efficiency for N could be improved by manipulating crop diversity using three annual crops (wheat, Triticum aestivum L.; canola, Brassica napus L.; and field pea, Pisum arvense L.) commonly grown on the Canadian Prairies. The study included all combinations of the crops (sole crops and intercrops) and compared their effects on soil N depletion, plant N concentration, plant N yield, and land equivalent ratios for dry matter and grain N yield (NLER) at two field sites in Manitoba, Canada. The pea sole crop treatment tended to result in higher fall soil nitrate (NO3−)–N concentrations compared to other treatments, indicating greater potential for post‐season NO3− leaching after this treatment. There were often greater N concentrations in wheat, canola, and weeds when grown in association with field pea, suggesting that soil N could have been made available for nonlegume uptake through the NO3−–N sparing effect On average, most intercrop treatments resulted in more efficient land use for N compared to component sole crops, with overall mean intercrop NLER values ranging from 1.10 to 1.20. The wheat–canola–pea and canola–pea intercrop treatments tended to produce the highest and most consistent NLER values for crop dry matter and grain yield, respectively. The results of this study suggest that intercrops could be used for more efficient use of N on a per land area basis.
Dry Matter Accumulation and Silage Moisture Changes after Silking in Leafy and Dual‐Purpose Corn Hybrids
Authors: Ma B. L. , Subedi K. D. , Stewart D. W. , Dwyer L. M.
Published: June 2006

The increasing use of new silage‐specific corn (Zea mays L.) hybrids, including Leafy types, has created a need for more information on the decision of hybrid choice and time of harvest. A field experiment including dual‐purpose and Leafy silage‐specific hybrids was conducted for 4 yr (1999–2002) at Ottawa, ON, Canada. Specific objectives were to determine (i) differences in whole plant moisture and dry matter (DM) accumulation after silking, and (ii) the optimum harvest windows of the contrasting corn types. Samples of whole plant moisture and DM accumulation were taken and analyzed at 3‐ to 7‐d intervals from approximately 3 wk after silking to physiological maturity. Our results showed that the rate of decline in silage moisture content varied among the years and hybrid types. On average, 85% of total DM accumulation was achieved when the whole plant moisture was about 65% for all hybrids. Compared to dual‐purpose hybrids, the whole plant moisture of Leafy silage‐specific hybrids declined more slowly, especially for hybrid ‘Mycogen TMF94’. We concluded that 65% whole plant moisture normally corresponded to the 50% kernel milk line (ML), and occurred between 50 and 60 d after silking under the northeast climate conditions. Silage‐specific hybrids had larger windows for harvest than dual‐purpose hybrids. However, ML progression was irregular for Leafy hybrids and changed more rapidly for dual‐purpose hybrids. Under extreme weather conditions, kernel ML does not correspond to silage moisture content in the same way as under normal conditions, therefore, silage harvest should be based on actual moisture content.
The Linear Markov Property in Credibility Theory
Authors: Witting Thomas
Published: June 2006

We study the linear Markov property, i.e. the possibility of basing the credibility estimator on data of the most recent time period without loss of accuracy. Necessary and sufficient conditions are derived generally. The meaning of the linear Markov property is also discussed in different experience rating and loss reserving models.
Minimum alveolar concentration of isoflurane in green iguanas and the effect of butorphanol on minimum alveolar concentration
Authors: Mosley Craig A. E. , Dyson Doris , Smith Dale A.
Published: June 2006

Objective—To determine minimum alveolar concentration (MAC) of isoflurane in green iguanas and effects of butorphanol on MAC.

Design—Prospective randomized trial.

Animals—10 healthy mature iguanas.

Procedure—In each iguana, MAC was measured 3 times: twice after induction of anesthesia with isoflurane and once after induction of anesthesia with isoflurane and IM administration of butorphanol (1 mg/kg [0.45 mg/lb]). A blood sample was collected from the tail vein for blood-gas analysis at the beginning and end of the anesthetic period. The MAC was determined with a standard bracketing technique; an electrical current was used as the supramaximal stimulus. Animals were artificially ventilated with a ventilator set to deliver a tidal volume of 30 mL/kg (14 mL/lb) at a rate of 4 breaths/min.

Results—Mean ± SD MAC values during the 3 trials (2 without and 1 with butorphanol) were 2.0 ± 0.6, 2.1 ± 0.6, and 1.7 ± 0.7%, respectively, which were not significantly different from each other. Heart rate and end-tidal partial pressure of CO2were also not significantly different among the 3 trials. Mean ± SD heart rate was 48 ± 10 beats/min; mean end-tidal partial pressure of CO2was 22 ± 10 mm Hg. There were no significant differences in blood-gas values for samples obtained at the beginning versus the end of the anesthetic period.

Conclusions and Clinical Relevance—Results suggest that the MAC of isoflurane in green iguanas is 2.1% and that butorphanol does not have any significant isoflurane-sparing effects. (J Am Vet Med Assoc2003;222:1559–1564)
Nail gun injuries in apprentice carpenters: Risk factors and control measures
Authors: Lipscomb Hester J. , Dement John M. , Nolan James , Patterson Dennis
Published: June 2006

Background

Nail guns increase residential construction productivity but their use is associated with risk of injury.

Methods

Active surveillance data from 772 apprentice carpenters were used to document the injury risk associated with the use of nail guns and the potential impact of modifiable risk factors. Using reported work hours and nail gun injuries injury rates per 200,000 hr worked in the past year were calculated. Using estimates of hours of tool use, Poisson regression was used to calculate adjusted rate ratios for injury associated with time in the trade, trigger mechanism on the tools and training prior to injury.

Results

Forty‐five percent of these apprentices had sustained a nail gun injury; injury rates in the past year based on hours of work were considerably higher than previously recognized. Those with less than 1 year in the trade compared to those with more than 5 years experience (RR = 2.7; 95% CI 1.2, 5.9) and those with no training in tool use (RR = 2.9; 95% CI 1.9, 4.4) were at greatest risk. After adjusting for experience and training, the rate of injury was twice as high with tools with a contact trip trigger compared to those with a sequential trigger (RR = 2.0; 95% CI 1.2, 3.3).

Conclusions

Preventive measures should include change to the safer sequential trigger that prevents unintentional firing and early training in safe tool use. Because of the high prevalence of use of tools with contact trip triggers the greatest number of injuries among these apprentices could be prevented with an engineering solution. Am. J. Ind. Med. 49:505–513, 2006. © 2006 Wiley‐Liss, Inc.
Impact of psychosocial job stress on non‐fatal occupational injuries in small and medium‐sized manufacturing enterprises
Authors: Nakata Akinori , Ikeda Tomoko , Takahashi Masaya , Haratani Takashi , Hojou Minoru , Fujioka Yosei , Swanson Naomi G. , Araki Shunichi
Published: June 2006

Background

Workers involved in manufacturing are known to comprise a high‐risk population for occupational injury, and this risk is greater in small and medium‐sized enterprises (SMEs). The purpose of this study was to examine the association between psychosocial job stress and occupational injuries among workers in SMEs.

Methods

One thousand forty‐nine men and 721 women from 244 SMEs participated in this study. Perceived job stress was evaluated with the Japanese version of the generic job stress questionnaire, which covered 14 job stress variables. Occupational injury was assessed by self‐report during the last 1‐year period.

Results

Workers with high quantitative workload (odds ratio [OR] = 1.55 for men, 1.62 for women), high cognitive demands (OR = 1.70 for men, 1.53 for women), and low job satisfaction (OR = 1.33 for men, 1.93 for women) had a significantly increased risk of occupational injury in the multivariate model. High variance in workload (OR = 1.70) and high job future ambiguity (OR = 1.35) in men, and low job control (OR = 2.04) and high intragroup conflict (OR = 1.66) in women were significantly associated with occupational injury. In manufacturing/production workers, high quantitative workload (OR = 1.91), high variance in workload (OR = 2.02), and high depressive symptoms (OR = 1.55) were significantly associated with injury in men, while low social support from colleagues (OR = 2.36) or family (OR = 2.51) was related to injury in women.

Conclusions

These data point to an independent relationship between psychosocial job stress and self‐reported occupational injury in SMEs.
Language evolution and the spread of ideas on the Web: A procedure for identifying emergent hybrid word family members
Authors: Thelwall Mike , Price Liz
Published: June 2006

Word usage is of interest to linguists for its own sake as well as to social scientists and others who seek to track the spread of ideas, for example, in public debates over political decisions. The historical evolution of language can be analyzed with the tools of corpus linguistics through evolving corpora and the Web. But word usage statistics can only be gathered for known words. In this article, techniques are described and tested for identifying new words from the Web, focusing on the case when the words are related to a topic and have a hybrid form with a common sequence of letters. The results highlight the need to employ a combination of search techniques and show the wide potential of hybrid word family investigations in linguistics and social science.
One digital library, two undergraduate classes, and four learning modules: Uses of a digital library in classrooms
Authors: Pan Bing , Gay Geri , Saylor John , Hembrooke Helene
Published: June 2006

The KMODDL (kinematic models for design digital library) is a digital library based on a historical collection of kinematic models made of steel and bronze. The digital library contains four types of learning modules including textual materials, QuickTime virtual reality movies, Java simulations, and stereolithographic files of the physical models. The authors report an evaluation study on the uses of the KMODDL in two undergraduate classes. This research reveals that the users in different classes encountered different usability problems, and reported quantitatively different subjective experiences. Further, the results indicate that depending on the subject area, the two user groups preferred different types of learning modules, resulting in different uses of the available materials and different learning outcomes. These findings are discussed in terms of their implications for future digital library design.
The Fumitremorgin Gene Cluster of Aspergillus fumigatus: Identification of a Gene Encoding Brevianamide F Synthetase
Authors: Maiya Shubha , Grundmann Alexander , Li Shu‐Ming , Turner Geoffrey
Published: June 2006

A gene encoding a putative dimodular nonribosomal peptide synthetase (NRPS) was identified within a gene cluster of Aspergillus fumigatus, a species reported to produce fumitremorgins and other prenylated alkaloids. The gene was deleted and overexpressed in the genome reference strain Af293, and was also expressed in the naïve host Aspergillus nidulans, which lacks the equivalent gene cluster. While neither fumitremorgins nor the dipeptide brevianamide F (cyclo‐L‐Trp‐L‐Pro), an early intermediate, were detected in wild‐type and deletion strains of A. fumigatus, brevianamide F accumulated in fungal cultures following increased expression of the NRPS gene in both A. fumigatus and A. nidulans. We conclude that the gene Afu8g00170, named ftmA, encodes the NRPS brevianamide synthetase. Brevianamide F is the precursor of a variety of fungal prenylated alkaloids with biological activity, including fumitremorgins A, B and C and tryprostatin B.
Comparative Analyses of a Family of Potential Self‐Replicators: The Subtle Interplay between Molecular Structure and the Efficacy of Self‐Replication
Authors: Pearson Russell J. , Kassianidis Eleftherios , Slawin Alexandra M. Z. , Philp Douglas
Published: June 2006

It is envisioned that protocols based on self‐replication will emerge as a formidable synthetic apparatus for the production of nanoscale assemblies through molecular structures that are capable of automultiplication with high reaction rates and selectivities. To achieve this goal, a complete understanding of the relationship between molecular structure and replication efficiency is necessary. Rigorous experimental and theoretical analyses of a series of self‐complementary scaffolds that are intimately related in a constitutional sense, manufactured through the Diels–Alder reaction of complementary subunits, were undertaken. Experimental and computational methods were employed to map the key determinants that dictate the emergence of self‐replicative function, as well as the efficiency, rate and selectivity of the self‐replicative processes.
Lanthanide Complexes of a Picolinate Ligand Derived from 1,4,7‐Triazacyclononane with Potential Application in Magnetic Resonance Imaging and Time‐Resolved Luminescence Imaging
Authors: Nonat Aline , Gateau Christelle , Fries Pascal H. , Mazzanti Marinella
Published: June 2006

The new potentially octadentate ligand, 1‐(carboxymethyl)‐4,7‐bis[(6‐carboxypyridin‐2‐yl)methyl]‐1,4,7‐triazacyclononane (H3bpatcn), in which two picolinate arms and one acetate arm are connected to the 1,4,7‐triazacyclonane core, has been prepared. Potentiometric studies show an increased stability of the GdIII complex of H3bpatcn (logKGdL=15.8(2)) with respect to the GdIII complex of the analogous ligand 1,4,7‐triazacyclononane‐N,N′,N′′‐triacetic acid (H3nota) (logKGdL=13.7), associated with an increased selectivity of H3bpatcn for gadolinium over calcium. The H3bpatcn ligand sensitises the terbium ion very efficiently, leading to a long‐lived and highly luminescent terbium complex (quantum yield=43 %), in spite of the presence of a coordinated water molecule. 1H proton NMR studies indicate that the metal ion is rigidly encapsulated by the three arms of the octadentate ligand H3bpatcn and that the macrocycle framework remains bound (through the five nitrogen and the three oxygen atoms) even at high temperature. A new theoretical method for interpreting the water proton relaxivity is presented. It is based on recent progresses in the description of the electronic spin relaxation and on an auxiliary probe solute. It replaces the Solomon, Bloembergen and Morgan (SBM) framework, which is questionable at low field, while avoiding resorting to simulations and/or sophisticated theories with additional unknown zero‐field splitting (ZFS) parameters. The inclusion of two picolinate groups on a triazacyclononane framework affords the mono‐aquo gadolinium complex [Gd(bpatcn)(H2O)] with favourable electron‐relaxation properties (${\tau {{{\rm eff}\hfill \atop {\rm S0}\hfill}}}$=125 ps). The optimisation of the electronic relaxation by ligand design is especially important to achieve high relaxivity in the new generation macromolecular complexes with long rotational correlation times.
Ab Initio and Experimental Thermodynamic and Kinetic Study of Proton‐Assisted Bond Activation in Gaseous Hydrocarbons: Deconvolution of Reaction Efficiencies in the Case of Adamantane
Authors: Dávalos Juan Z. , Herrero Rebeca , Quintanilla Esther , Jiménez Pilar , Gal Jean‐François , Maria Pierre‐Charles , Abboud José‐Luis M.
Published: June 2006

1) Protonation at all possible sites of adamantane (C10H16) was studied at the MP2/6‐311++G(3df,2p)//MP2/6‐311++G(d,p) level. This provided values of the changes in the thermodynamic state functions for these processes. Whenever direct comparison was possible, the agreement with experimental data was very good. 2) By the same means, the reaction paths linking the various species obtained in these reactions were analyzed. 3) Fourier transform ion cyclotron resonance (FT‐ICR) spectroscopy was used to determine the rate constants for proton transfer from 16 protonated reference bases to adamantane in the gas phase. Also, the rate constants for the formation of ionic products in these reactions were determined. 4) The experimental reaction rates were successfully predicted and refined on the basis of a simple mechanistic model based on the reaction profiles indicated above. 5) Our results hint at the potential usefulness of this approach for mechanistic studies.
The Mechanistic Puzzle of Transition‐Metal‐Catalyzed Skeletal Rearrangements of Enynes
Authors: Nieto‐Oberhuber Cristina , López Salomé , Jiménez‐Núñez Eloísa , Echavarren Antonio M.
Published: June 2006

Three pathways actually compete in metal‐catalyzed cyclizations of enynes in which the metal selectively activates the alkyne: an endocyclic process and two exo‐cyclizations, one proceeding by anti attack of the alkene and a second one resulting in a syn addition. Although cyclobutenes may be formed in transition‐metal‐catalyzed cyclization of some enynes, particularly, 1,7‐enynes, these compounds are not necessarily the intermediates in the skeletal rearrangement. Cyclobutenes are formed by ring expansion of syn‐cyclopropyl metal–carbenes formed in the syn pathway.
The Adaptable Lyonsite Structure
Authors: Smit Jared P. , Stair Peter C. , Poeppelmeier Kenneth R.
Published: June 2006

Crystal frameworks that can accommodate a wide range of elements, oxidation states, and stoichiometries are an important component of solid‐state chemistry. These frameworks allow for unique comparisons of different metal‐cation compositions with identical atomic arrangements. The mineral Lyonsite, α‐Cu3Fe4(VO4)6, is emerging as the archetypal framework structure for a large class of materials, similar to known frameworks such as perovskite, garnet, apatite, and spinel. The new lyonsite‐type oxides Li2.82Hf0.795Mo3O12 and Li3.35Ta0.53Mo3O12, in which hafnium and tantalum retain their highest oxidation states, are presented to advance the concept of the lyonsite structure as an adaptable framework.
Predicting the Shape and Structure of Face‐Centered Cubic Gold Nanocrystals Smaller than 3 nm
Authors: Barnard Amanda S. , Curtiss Larry A.
Published: June 2006

Although a number of computational studies have examined the relative stability of icosahedral and decahedral gold clusters from 1 to 3 nm in size, few studies have focussed on the variety of face‐centered cubic (fcc) nanoparticles in this size regime. In most cases small fcc gold particles are assumed to adopt the truncated octahedral shape, but in light of the fact that the shape and structure of gold nanoparticles is known to vary, the relative stability of fcc polyhedra may change with size. Presented here are results of first‐principles calculations investigating the preferred shape of gold particles less than 3 nm in size. Our results indicate that the equilibrium shape of fcc gold nanoparticles less than 1 nm is the cuboctahedron, but this shape rapidly becomes energetically unstable with respect to the truncated octahedron, octahedron and truncated cube shapes as the size increases.
Synthesis, Characterization, and Crystal Structure Analysis of the First Terdentate [C,N,S] Thiosemicarbazone Complex with a Six‐Membered Palladacycle: Influence of Steric Effects on Ring Size
Authors: Amoedo Adriana , Adrio Luis A. , Antelo José M. , Martínez Javier , Pereira M. Teresa , Fernández Alberto , Vila José M.
Published: June 2006

The reaction of the thiosemicarbazone ligands 1‐(COMe)‐3‐[C(H)=NN(H)C(=S)NHR]C8H5N, (R = H a, Me b, Et c) with potassium tetrachloropalladate in an ethanol/water mixture led to the new tetranuclear palladium(II) compounds [Pd{1‐(COMe)‐3‐[C(H)=NN=C(S)NHR]C8H4N‐k3C5,N,S}]4 (R = H 1a, Me 1b, Et 1c) which contain six‐membered metallacycles. The thiosemicarbazone ligands in these complexes are terdentate through the C, N, and S atoms and are deprotonated at the NH group. The Pd–S bond formed is sufficiently strong to undergo reactions with nucleophiles without bond cleavage. Reaction of 1a and 1b with 1,2‐bis(diphenylphosphanyl)ethane (dppe) gave the dinuclear species [{Pd[1‐(COMe)‐3‐{C(H)=NN=C(S)NHR}C8H4N]}2(μ‐Ph2P(CH2)2PPh2)] (R = H 2a, Me 2b). The molecular structure of complex 1b has been determined by X‐ray diffraction analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Symmetrisation in the Interaction of Chloro[2‐(dimethylaminomethyl)phenyl‐C1]mercury(II) with Thiosemicarbazone Derivatives of Pyridine‐2‐carboxamide and Pyrazin‐2‐carboxamide
Authors: Abram Ulrich , Castiñeiras Alfonso , García‐Santos Isabel , Rodríguez‐Riobó Raul
Published: June 2006

Pyridine‐ and pyrazine‐2‐carboxamide thiosemicarbazones (HAm4DH and HAmpz4DH) or their N4,N4‐dimethyl derivatives (HAm4DM and HAmpz4DM) react with chloro[2‐(dimethylaminomethyl)phenyl‐C1]mercury(II), [Hg(damp)Cl], to give the tetrahedral [Hg(TSC)2] complexes [TSC = Am4DH (1), Am4DM (2), Ampz4DH (3) or Ampz4DM (4)]. Spectroscopic studies and a X‐ray structural analysis show that the potentially tridentate thiosemicarbazones adopt S,N coordination modes, with each deprotonated thiosemicarbazone binding to the HgII centre through the azomethine nitrogen and the thiolate sulfur atoms, whereas the heterocyclic nitrogen atoms are free of coordination. Intra‐ and intermolecular hydrogen bonding in all complexes and specific C–H···π interactions with the chelate or pyridyl rings of the complexes 1 and 2 were found in the crystal structures. Furthermore, [Hg(damp)Cl] undergoes symmetrisation to give the symmetric unit [Hg(Hdamp)2]2+ in which the Hdamp is protonated at the nitrogen. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Reduction in the mutagenicity of synthetic dyes by successive treatment with activated sludge and the ligninolytic fungus, Irpex lacteus
Authors: Malachová Katerina , Pavlícková Zuzana , Novotný Cenek , Svobodová Katerina , Lednická Denisa , Musílková Eva
Published: June 2006

Synthetic dyes are released in wastewater from textile manufacturing plants, and many of these dyes are genotoxic. In the present study, the mutagenicity of azo, anthraquinone, and triphenyl methane dyes was investigated before and after successive biodegradation with activated sludge and the ligninolytic fungus, Irpex lacteus. Two biodegradation systems were used to reduce the genotoxicity of dyes that were not efficiently inactivated by activated sludge alone. Mutagenicity was monitored with the Salmonella reversion assay conducted with the base‐pair substitution detector strains, TA100 and YG1042, and the frame‐shift detector strains, TA98 and YG1041, with and without rat liver S9. All dyes except for Congo Red (CR) were mutagenic with S9 activation. Assays conducted with the dyes indicated that only the azo dye Reactive Orange 16 (RO16) was mutagenic in both TA98 and TA100. Methyl Red and Disperse Blue 3 (DB3) were mutagenic in TA98, YG1041 and YG1042, while Reactive Black 5 was mutagenic in YG1041 and YG1042. Remazol Brilliant Blue R (RBBR), Crystal violet (CV) and Bromophenol Blue (BPB) were mutagenic only in TA98, but the toxicity of the latter two dyes complicated the evaluation of their mutagenicity. CR was not mutagenic in any of the tester strains. Biodegradation studies conducted with RO16 and DB3 indicated that the two‐step biodegradation process reduced the mutagenic potential of RO16 and DB3 to a greater extent than activated sludge alone; the mutagenicity of the two dyes was reduced by 95.2% and 77.8%, respectively, by the two‐step process. These data indicate that the combined biodegradation process may be useful for reducing the mutagenicity associated with wastewater from textile factories that contain recalcitrant dyes. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.
Porous chitosan tubular scaffolds with knitted outer wall and controllable inner structure for nerve tissue engineering
Authors: Wang Aijun , Ao Qiang , Cao Wenling , Yu Mingzhi , He Qing , Kong Lijun , Zhang Ling , Gong Yandao , Zhang Xiufang
Published: June 2006

In this study, a novel method was developed to create porous tubular scaffolds with desirable mechanical properties and controllable inner structure from chitosan, for nerve tissue engineering. Chitosan fiber‐based yarns were first used to create porous hollow tubes, which served as the outer wall of the scaffolds, through an industrial knitting process. Then, an innovative molding technique was developed and used to produce inner matrices with multiple axially oriented macrochannels and radially interconnected micropores. Acupuncture needles were used as mandrels during molding to improve the safety and controllability of the process. In vitro characterization demonstrated that the scaffolds possessed suitable mechanical strength, porosity, swelling, and biodegradability for applications in nerve tissue engineering. In vitro cell culture experiments showed that differentiated Neuro‐2a cells grew along the oriented macrochannels and the interconnected micropores were beneficial for nutrient diffusion and cell ingrowth to the scaffold's interior. Collectively, the well‐defined architectural features in addition to the desirable mechanical and biological properties of the scaffolds make them promising for nerve tissue engineering. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
The effects of embedding material, loading rate and magnitude, and penetration depth in nanoindentation of trabecular bone
Authors: Mittra Erik , Akella Sailaja , Qin Yi‐Xian
Published: June 2006

Understanding the pathophysiology of metabolic bone disease requires the characterization of both the quantity as well as the quality (i.e., microarchitecture and material properties) of the bone tissue. Nanoindentation provides a powerful yet simple method to measure the nano/micro mechanical properties of bone, but no uniform testing methodology exists. This study examines the effects of embedding materials, rate and depth of indentation, and storage time on the measured modulus. Nineteen trabecular bone samples were evaluated for the study. Although there was an 8‐fold increase in the stiffness of the soft to hard epoxy, bone tissue modulus was not affected by the stiffness of the embedding materials, but hardness was affected by both the embedding material modulus, for example from 0.70 ± 0.20 GPa (MElow) to 0.45 ± 0.21 GPa (MEMed) (p < 0.01), and viscosity (p < 0.01). No significant differences were found with regard to the tested rates and depths of indentation for either elastic modulus or hardness. The tissue modulus tested at the 6‐month time point was significantly greater in comparison with that tested at 0 or 3 months (p < 0.01). The hardness, however, did not significantly change over the span of 6 months. The results show that while nanoindentation is powerful, it is particularly sensitive to certain testing variables. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Improved drug delivery properties of PVDF membranes functionalized with β‐cyclodextrin—Application to guided tissue regeneration in periodontology
Authors: Boschin F. , Blanchemain N. , Bria M. , Delcourt‐Debruyne E. , Morcellet M. , Hildebrand H.F. , Martel B.
Published: June 2006

The purpose of this study was to develop a membrane for guided tissue regeneration applicable in periodontology that could release antimicrobial agent during the healing period. Our strategy consisted to graft β‐cyclodextrin (β‐CD), a molecule that is known to form inclusion complexes with a large variety of drugs, onto PVDF membranes. Grafting occurred by using citric acid that provoked a crosslinking reaction of β‐CD, and the resulting polymer was imprisoned into the porous structure of the PVDF membrane. The reaction produced a weight increase of the membrane, the range of which depended on the temperature and on the time of curing applied in the process. The biological behavior of the membranes evaluated by proliferation and vitality tests showed good proliferation and improved activity of L132 epithelial cells on the raw and on the grafted membranes. Doxycyclin (DOX) and chlorhexidine (CHX) were used as antimicrobial agents. Their inclusion into the β‐CD cavity in aqueous solutions was confirmed by NMR spectroscopy. After the impregnation of the membranes with DOX and CHX, their release was studied in vitro in batch type experiments and measured by UV spectrophotometry. Low amounts of DOX and CHX were delivered from the raw membranes within the first few hours of tests. Grafted membranes, however, delivered DOX and CHX in larger quantities within 24 h and 10 days respectively. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Directed type IV collagen self‐assembly on hydroxylated PTFE
Authors: Ludwig Nicholas S. , Yoder Colin , McConney Michael , Vargo Terrence G. , Kader Khalid N.
Published: June 2006

A method for the creation of a type IV collagen (CNIV) scaffold on polytetrafluoroethylene (PTFE) for endothelial cell attachment is described. This mimic for the basal lamina can be used in the seeding and retention of endothelial cells for blood contacting devices. The CNIV‐PTFE production technique can be defined as three processes: (i) creation of a reactive superacidic/ionic PTFE surface with retained hydrophobic characteristics; (ii) activation of this surface via covalent attachment of N‐(3‐dimethylaminopropyl)‐N′‐ethylcarbodiimide (EDC); and (iii) conjugation of the EDC with human CNIV resulting in the covalent binding of protein to the PTFE surface. This article demonstrates exciting new results showing that a reaction of CNIV to this particular surface results in a unique matrix assembly of CNIV scaffolds similar to those found in the basal lamina. This assembly is concentration‐dependant, occurring in a narrow window around 0.435 μM. Following the fabrication of the CNIV matrix assembly, porcine aortic endothelial cells (PAEC) were seeded onto this material. Results described in this article demonstrate that the PAEC subsequently aligned with the direction of shear, filled voids created by dead or detached cells, and divided during the 6 h of experimentation. Under static conditions, cells remained viable for 1 week of testing. This was not observed with PAEC attached to glass with adsorbed Vitrogen. In summary, this article describes a novel biotechnological breakthrough that enables the creation of stable endothelial cell monolayers useful for fabricating blood contacting devices. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Stress response of adherent cells on a polymer blend surface composed of a segmented polyurethane and MPC copolymers
Authors: Sawada Shin‐Ichi , Iwasaki Yasuhiko , Nakabayashi Nobuo , Ishihara Kazuhiko
Published: June 2006

To better understand the effect of 2‐methacryloyloxyethyl phosphorylcholine (MPC) copolymer in improving the biocompatibility of segmented polyurethane (SPU), the expression of heat shock protein (HSP) mRNA in HeLa S3 cells adhered on SPU blended with MPC copolymers was measured. Conventionally, MPC copolymers (PMEH) were synthesized by changing the feed ratios of MPC and 2‐ethylhexyl methacrylate. X‐ray photoelectron spectroscopic analysis of the SPU/PMEH film indicated that the surface concentration of MPC units on the SPU/PMEH film increased with an increase in PMEH composition. HeLa S3 cells were cultured on SPU/PMEH films. The number of adherent cells on the SPU/PMEH films decreased with an increase in the concentration of PMEH. When the PMEH composition was greater than 0.5 wt %, cell adhesion and proliferation decreased markedly. Expressions of HSP27 and HSP47 mRNA were detected using the reverse transcription‐polymerase chain reaction (RT‐PCR). After incubation for 24 h, both the HSP mRNA expressions in the HeLa S3 cells showed no significant differences among all samples. In HeLa S3 cells that adhered to the SPU film for 48 h, the expressions of HSP27 and HSP47 mRNA increased significantly when compared with those incubated for 24 h. In contrast, the two kinds of mRNA expressions decreased in the HeLa S3 cells that adhered to the SPU/PMEH films for 48 h. From these results, we concluded that PMEH was quite important in suppressing the stress response of adherent HeLa S3 cells. Therefore, SPU/PMEH blend polymers are useful as implantable biomedical materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Lean health care: What can hospitals learn from a world‐class automaker?
Authors: Kim Christopher S. , Spahlinger David A. , Kin Jeanne M. , Billi John E.
Published: June 2006

BACKGROUND

With health care costs continuing to rise, a variety of process improvement methodologies have been proposed to address the reported inefficiencies in health care delivery. Lean production is one such method. The management philosophy and tools of lean production come from the manufacturing industry, where they were pioneered by Toyota Motor Corporation, which is viewed as the leader in utilizing these performance improvement methods. Lean has already enjoyed tremendous success in improving quality and efficiency in both the manufacturing and the service sector industries.

RESULTS

Health care systems have just begun to utilize lean methods, with reports of improvements just beginning to appear in the literature. We describe some of the basic philosophy and principles of lean production methods and how these concepts can be applied in the health care environment. We describe some of the early success stories and ongoing endeavors of lean production in various health care organizations. We believe the hospital is an ideal setting for use of the lean production method, which could significantly affect how health care is delivered to patients.

CONCLUSIONS

We conclude by discussing some of the potential challenges in introducing and implementing lean production methods in the health care environment. Lean production is a novel approach to delivering high‐quality and efficient care to patients, and we believe that the health care sector can anticipate the same high level of success that the manufacturing and service industries have achieved using this approach. Hospitalists are primed to take action in delivering care of greater quality with more efficiency by applying these new principles in the hospital setting. Journal of Hospital Medicine 2006;1:191–199. © 2006 Society of Hospital Medicine.