bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dynamics of Developmental and Tumor Angiogenesis—A Comparison
Authors: Jin Yi , Jakobsson Lars
Published: April 2012

The blood vasculature in cancers has been the subject of intense interest during the past four decades. Since the original ideas of targeting angiogenesis to treat cancer were proposed in the 1970s, it has become evident that more knowledge about the role of vessels in tumor biology is needed to fully take advantage of such strategies. The vasculature serves the surrounding tissue in a multitude of ways that all must be taken into consideration in therapeutic manipulation. Aspects of delivery of conventional cytostatic drugs, induction of hypoxia affecting treatment by radiotherapy, changes in tumor cell metabolism, vascular leak and trafficking of leukocytes are affected by interventions on vascular function. Many tumors constitute a highly interchangeable milieu undergoing proliferation, apoptosis, and necrosis with abundance of growth factors, enzymes and metabolites. These aspects are reflected by the abnormal tortuous, leaky vascular bed with detached mural cells (pericytes). The vascular bed of tumors is known to be unstable and undergoing remodeling, but it is not until recently that this has been dynamically demonstrated at high resolution, facilitated by technical advances in intravital microscopy. In this review we discuss developmental genetic loss-of-function experiments in the light of tumor angiogenesis. We find this a valid comparison since many studies phenocopy the vasculature in development and tumors.
Synthesis and Crystal Structures of the Quaternary Zintl Phases RbNa8Ga3Pn6 (Pn = P, As) and Na10NbGaAs6
Authors: He Hua , Tyson Chauntae , Bobev Svilen
Published: April 2012

The new Zintl compounds RbNa8Ga3Pn6 (Pn = P, As) and Na10NbGaAs6 have been synthesized from the corresponding elements at high temperatures. RbNa8Ga3P6 and RbNa8Ga3As6 crystallize with a novel structure type that features trigonal planar [Ga3P6]9– and [Ga3As6]9– motifs, which are isosteric with the 1,3,5-trioxanetrione (a cyclic trimer of carbon dioxide). Na10NbGaAs6, an unforeseen side product of the same reactions boasts a structure, which is based on NbAs4 and GaAs4 tetrahedra, condensed by sharing common edges into [NbGaAs6]10– dimers. The bonding characteristics of both structures are discussed. All three compounds reported herein represent the first compounds found in the respective quaternary systems.
Entropy Generation During the Interaction of Thermal Radiation with a Surface
Authors: Kabelac Stephan , Conrad Rainer
Published: April 2012

The entropy calculation for radiation fluxes is reviewed and applied to simple radiation-surface interactions. A plate interacting with radiation from a hot object in the zenith of the hemisphere surrounded by a colder atmosphere is analyzed in detail. The entropy generation rate upon absorption and reflection of the incoming radiation is calculated and discussed. The plate is adiabatic in a first version (thermal equilibrium), then its temperature is fixed by allowing a heat flux to or from the plate. This analysis prepares the way towards an entropy generation minimization analysis of more complex radiation settings.
Evaluation of Changes in Effluent Quality from Industrial Complexes on the Korean Nationwide Scale Using a Self-Organizing Map
Authors: Bae Mi-Jung , Kim Jun-Su , Park Young-Seuk
Published: April 2012

One of the major issues related to the environment in the 21st century is sustainable development. The innovative economic growth policy has supported relatively successful economic development, but poor environmental conservation efforts, have consequently resulted in serious water quality pollution issues. Hence, assessments of water quality and health are fundamental processes towards conserving and restoring aquatic ecosystems. In this study, we characterized spatial and temporal changes in water quality (specifically physico-chemical variables plus priority and non-priority pollutants) of discharges from industrial complexes on a national scale in Korea. The data were provided by the Water Quality Monitoring Program operated by the Ministry of Environment, Korea and were measured from 1989 to 2008 on a monthly basis at 61 effluent monitoring sites located at industrial complexes. Analysis of monthly and annual changes in water quality, using the seasonal Mann-Kendall test, indicated an improvement in water quality, which was inferred from a continuous increase in dissolved oxygen and decrease in other water quality factors. A Self-Organizing Map, which is an unsupervised artificial neural network, also indicated an improvement of effluent water quality, by showing spatial and temporal differences in the effluent water quality as well as in the occurrence of priority pollutants. Finally, our results suggested that continued long-term monitoring is necessary to establish plans and policies for wastewater management and health assessment.
Cell Adhesion and Its Endocytic Regulation in Cell Migration during Neural Development and Cancer Metastasis
Authors: Kawauchi Takeshi
Published: April 2012

Cell migration is a crucial event for tissue organization during development, and its dysregulation leads to several diseases, including cancer. Cells exhibit various types of migration, such as single mesenchymal or amoeboid migration, collective migration and scaffold cell-dependent migration. The migration properties are partly dictated by cell adhesion and its endocytic regulation. While an epithelial-mesenchymal transition (EMT)-mediated mesenchymal cell migration requires the endocytic recycling of integrin-mediated adhesions after the disruption of cell-cell adhesions, an amoeboid migration is not dependent on any adhesions to extracellular matrix (ECM) or neighboring cells. In contrast, a collective migration is mediated by both cell-cell and cell-ECM adhesions, and a scaffold cell-dependent migration is regulated by the endocytosis and recycling of cell-cell adhesion molecules. Although some invasive carcinoma cells exhibit an EMT-mediated mesenchymal or amoeboid migration, other cancer cells are known to maintain cadherin-based cell-cell adhesions and epithelial morphology during metastasis. On the other hand, a scaffold cell-dependent migration is mainly utilized by migrating neurons in normal developing brains. This review will summarize the structures of cell adhesions, including adherens junctions and focal adhesions, and discuss the regulatory mechanisms for the dynamic behavior of cell adhesions by endocytic pathways in cell migration in physiological and pathological conditions, focusing particularly on neural development and cancer metastasis.
Effect of Maturity on Phenolics (Phenolic Acids and Flavonoids) Profile of Strawberry Cultivars and Mulberry Species from Pakistan
Authors: Mahmood Tahir , Anwar Farooq , Abbas Mateen , Saari Nazamid
Published: April 2012

In this study, we investigated how the extent of ripeness affects the yield of extract, total phenolics, total flavonoids, individual flavonols and phenolic acids in strawberry and mulberry cultivars from Pakistan. In strawberry, the yield of extract (%), total phenolics (TPC) and total flavonoids (TFC) ranged from 8.5–53.3%, 491–1884 mg gallic acid equivalents (GAE)/100 g DW and 83–327 mg catechin equivalents (CE)/100 g DW, respectively. For the different species of mulberry the yield of extract (%), total phenolics and total flavonoids of 6.9–54.0%, 201–2287 mg GAE/100 g DW and 110–1021 mg CE/100 g DW, respectively, varied significantly as fruit maturity progressed. The amounts of individual flavonols and phenolic acid in selected berry fruits were analyzed by RP-HPLC. Among the flavonols, the content of myricetin was found to be high in Morus alba (88 mg/100 g DW), the amount of quercetin as high in Morus laevigata (145 mg/100 g DW) while kaempferol was highest in the Korona strawberry (98 mg/100 g DW) at fully ripened stage. Of the six phenolic acids detected, p-hydroxybenzoic and p-coumaric acid were the major compounds in the strawberry. M. laevigata and M. nigra contained p-coumaric acid and vanillic acid while M. macroura and M. alba contained p-hydroxy-benzoic acid and chlorogenic acid as the major phenolic acids. Overall, a trend to an increase in the percentage of extraction yield, TPC, TFC, flavonols and phenolic acids was observed as maturity progressed from un-ripened to fully-ripened stages.
Preparation and Elastic Moduli of Germanate Glass Containing Lead and Bismuth
Authors: Sidek Hj A. A. , Bahari Hamid R. , Halimah Mohamed K. , Yunus Wan M. M.
Published: April 2012

This paper reports the rapid melt quenching technique preparation for the new family of bismuth-lead germanate glass (BPG) systems in the form of (GeO2)60–(PbO)40−x–(½Bi2O3)x where x = 0 to 40 mol%. Their densities with respect of Bi2O3 concentration were determined using Archimedes’ method with acetone as a floatation medium. The current experimental data are compared with those of bismuth lead borate (B2O3)20–(PbO)80−x–(Bi2O3)x. The elastic properties of BPG were studied using the ultrasonic pulse-echo technique where both longitudinal and transverse sound wave velocities have been measured in each glass samples at a frequency of 15 MHz and at room temperature. Experimental data shows that all the physical parameters of BPG including density and molar volume, both longitudinal and transverse velocities increase linearly with increasing of Bi2O3 content in the germanate glass network. Their elastic moduli such as longitudinal, shear and Young’s also increase linearly with addition of Bi2O3 but the bulk modulus did not. The Poisson’s ratio and fractal dimensionality are also found to vary linearly with the Bi2O3 concentration.
Chemical Characteristics and Antioxidant Properties of Crude Water Soluble Polysaccharides from Four Common Edible Mushrooms
Authors: He Jin-Zhe , Ru Qiao-Mei , Dong Dan-Dan , Sun Pei-Long
Published: April 2012

Four crude water soluble polysaccharides, CABP, CAAP, CFVP and CLDP, were isolated from common edible mushrooms, including Agaricus bisporus, Auricularia auricula, Flammulina velutipes and Lentinus edodes, and their chemical characteristics and antioxidant properties were determined. Fourier Transform-infrared analysis showed that the four crude polysaccharides were all composed of β-glycoside linkages. The major monosaccharide compositions were D-galactose, D-glucose and D-mannose for CABP, CAAP and CLDP, while CFVP was found to consist of L-arabinose, D-galactose, D-glucose and D-mannose. The main molecular weight distributions of CABP and the other three polysaccharides were 66.0 × 104 Da, respectively. Antioxidant properties of the four polysaccharides were evaluated in in vitro systems and CABP showed the best antioxidant properties. The studied mushroom species could potentially be used in part of well-balanced diets and as a source of antioxidant compounds.
Adsorption Behavior of Fe(II) and Fe(III) Ions on Thiourea Cross-Linked Chitosan with Fe(III) as Template
Authors: Dai Jun , Ren FengLian , Tao ChunYuan
Published: April 2012

A new type of thiourea cross-linked chitosan with Fe(III) as template (TCCTS template) was synthesized. The adsorption of Fe(II) and Fe(III) on this TCCTS template was studied. The factors affecting adsorption such as pH and contact time were considered. The results showed that the optimum pH value for adsorption was pH = 5.0 and the adsorption equilibrium time was about 60 min. The adsorption isotherms and kinetics were investigated, and the equilibrium data agreed very well with the Langmuir model and the pseudo second-order model could describe adsorption process better than the pseudo first-order model. Results also showed that TCCTS template was a favourable adsorbent for Fe(II) and Fe(III) in aqueous solution.
Res aut res publica: The Evidence from Italian Renaissance Manuscripts and Their Owners
Authors: McManamon John M.
Published: April 2012

This paper examines a key tension in Renaissance culture as reflected in the origin and provenance of manuscript books. Were Renaissance manuscripts the private property of individual owners or the common wealth of a lettered public? Even an officially public library could not escape that tension, whether through abuse of borrowing privileges or plundering of vulnerable holdings. Market forces encouraged theft, while impoverished scholars used their knowledge to supplement meager incomes. Alternatively, a sense of common wealth is reflected in an ex-libris indicating that a codex belonged to an individual “and his friends.” Book collecting, finally, becomes a helpful clue in discerning to what a scholar is committed. Some Renaissance clergymen used culture as a way to promote their ecclesiastical careers, while others collected and shared manuscripts as a way to promote tolerance.
Karl Mannheim’s Jewish Question
Authors: Kettler David , Meja Volker
Published: April 2012

In this paper, we explore Karl Mannheim’s puzzling failure (or refusal) to address himself in any way to questions arising out of the position of Jews in Germany, either before or after the advent of Nazi rule—and this, notwithstanding the fact, first, that his own ethnic identification as a Jew was never in question and that he shared vivid experiences of anti-Semitism, and consequent exile from both Hungary and Germany, and, second, that his entire sociological method rested upon using one’s own most problematic social location—as woman, say, or youth, or intellectual—as the starting point for a reflexive investigation. It was precisely Mannheim’s convictions about the integral bond between thought grounded in reflexivity and a mission to engage in a transformative work of Bildung that made it effectively impossible for him to formulate his inquiries in terms of his way of being Jewish. It is through his explorations of the rise and fall of the intellectual as socio-cultural formation that Mannheim investigates his relations to his Jewish origins and confronts the disaster of 1933. The key to our puzzle is to be found in the theory of assimilation put forward in the dissertation of his student, Jacob Katz.
A Sensitivity-Enhanced Refractive Index Sensor Using a Single-Mode Thin-Core Fiber Incorporating an Abrupt Taper
Authors: Shi Jie , Xiao Shilin , Yi Lilin , Bi Meihua
Published: April 2012

A sensitivity-enhanced fiber-optic refractive index (RI) sensor based on a tapered single-mode thin-core diameter fiber is proposed and experimentally demonstrated. The sensor head is formed by splicing a section of tapered thin-core diameter fiber (TCF) between two sections of single-mode fibers (SMFs). The cladding modes are excited at the first SMF-TCF interface, and then interfere with the core mode at the second interface, thus forming an inter-modal interferometer (IMI). An abrupt taper (tens of micrometers long) made by the electric-arc-heating method is utilized, and plays an important role in improving sensing sensitivity. The whole manufacture process only involves fiber splicing and tapering, and all the fabrication process can be achieved by a commercial fiber fusion splicer. Using glycerol and water mixture solution as an example, the experimental results show that the refractive index sensitivity is measured to be 0.591 nm for 1% change of surrounding RI. The proposed sensor structure features simple structure, low cost, easy fabrication, and high sensitivity.
Improvement of Toluene Selectivity via the Application of an Ethanol Oxidizing Catalytic Cell Upstream of a YSZ-Based Sensor for Air Monitoring Applications
Authors: Sato Tomoaki , Breedon Michael , Miura Norio
Published: April 2012

The sensing characteristics of a yttria-stabilized zirconia (YSZ)-based sensor utilizing a NiO sensing-electrode (SE) towards toluene (C7H8) and interfering gases (C3H6, H2, CO, NO2 and C2H5OH) were evaluated with a view to selective C7H8 monitoring in indoor atmospheres. The fabricated YSZ-based sensor showed preferential responses toward 480 ppb C2H5OH, rather than the target 50 ppb C7H8 at an operational temperature of 450 °C under humid conditions (RH ⋍ 32%). To overcome this limitation, the catalytic activity of Cr2O3, SnO2, Fe2O3 and NiO powders were evaluated for their selective ethanol oxidation ability. Among these oxides, SnO2 was found to selectively oxidize C2H5OH, thus improving C7H8 selectivity. An inline pre-catalytic cell loaded with SnO2 powder was installed upstream of the YSZ-based sensor utilizing NiO-SE, which enabled the following excellent abilities by selectively catalyzing common interfering gases; sensitive ppb level detection of C7H8 lower than the established Japanese Guideline value; low interferences from 50 ppb C3H6, 500 ppb H2, 100 ppb CO, 40 ppb NO2, as well as 480 ppb C2H5OH. These operational characteristics are all indicative that the developed sensor may be suitable for real-time C7H8 concentration monitoring in indoor environments.
On the Selection of Transmission Range in Underwater Acoustic Sensor Networks
Authors: Gao Mingsheng , Foh Chuan Heng , Cai Jianfei
Published: April 2012

Transmission range plays an important role in the deployment of a practical underwater acoustic sensor network (UWSN), where sensor nodes equipping with only basic functions are deployed at random locations with no particular geometrical arrangements. The selection of the transmission range directly influences the energy efficiency and the network connectivity of such a random network. In this paper, we seek analytical modeling to investigate the tradeoff between the energy efficiency and the network connectivity through the selection of the transmission range. Our formulation offers a design guideline for energy-efficient packet transmission operation given a certain network connectivity requirement.
Protecting People, Infrastructure, Economies, and Ecosystem Assets: Water Management in the Face of Climate Change
Authors: Bloetscher Frederick
Published: April 2012

Recent literature outlines significant impacts from climate change on many areas of the world, with much focus on causes and impacts. However the long-term trends demand adaptation strategies. While a variety of solutions have been suggested, some politically viable, others not, perhaps the most significant barrier to a cohesive approach to climate adaptation is the failure from the public and policy-makers to realize that different areas will be affected differently and that “one-size-fits-all” policy solutions will not be successful. In addition, as one area may identify and respond to challenges in their location, others should be supportive of those efforts, realizing that while such actions may be neither desirable nor appropriate for them, they may need support for solutions in the future in their areas. This project was designed as a framework to identify solutions and demonstrate differences between small regions and locales based on field conditions. The State of Florida was used as a case example to outline these differences because Florida is faced with significant challenges in the coming years related to water resources, the use of funds and political capital, and the potential for economic disruption. The intent is that the results of this project will lead to a series of recommendations and action steps for policy makers to conserve the state’s assets. A similar approach can be used in other states and countries to assess the likely policy and infrastructure needs for different locales.
Synthesis of szentiamide, a depsipeptide from entomopathogenic Xenorhabdus szentirmaii with activity against Plasmodium falciparum
Authors: Nollmann Friederike I , Dowling Andrea , Kaiser Marcel , Deckmann Klaus , Grösch Sabine , ffrench-Constant Richard , Bode Helge B
Published: April 2012

The synthesis of the recently characterized depsipeptide szentiamide (1), which is produced by the entomopathogenic bacterium Xenorhabdus szentirmaii, is described. Whereas no biological activity was previously identified for 1, the material derived from the efficient synthesis enabled additional bioactivity tests leading to the identification of a notable activity against insect cells and Plasmodium falciparum, the causative agent of malaria.
Catalyst-free and solvent-free Michael addition of 1,3-dicarbonyl compounds to nitroalkenes by a grinding method
Authors: Xie Zong-Bo , Wang Na , Wu Ming-Yu , He Ting , Le Zhang-Gao , Yu Xiao-Qi
Published: April 2012

An environmentally benign, fast and convenient protocol has been developed for the Michael addition of 1,3-dicarbonyl compounds to β-nitroalkenes in good to excellent yields by a grinding method under catalyst- and solvent-free conditions.
L'argent dans la cure au temps de Freud
Authors: Sédat Jacques
Published: April 2012

Résumé Les positions personnelles et théoriques de Freud sur le rôle l’argent dans la cure sont loin d’être univoques. Freud expose le rôle exigible de l’argent dans la cure, dans le texte « Sur l’engagement du traitement » en 1913. Mais, après la guerre de 1914-18, Freud s’oriente vers une position plus favorable à la gratuité des soins pour les plus démunis, ce qui sera mis en pratique dans la Polyclinique de Berlin, en 1920.
Le prix du sacrifice
Authors: Aguerre Jean-Claude
Published: April 2012

Résumé Le paiement d’une séance d’analyse n’entre pas dans les modes habituels de transactions financières. Le règlement d’une séance par un analysant s’apparente davantage à un don d’argent, voire à un sacrifice. Cette notion de sacrifice illustre en outre ce à quoi le sujet doit renoncer pour entrer en analyse.
Le premier transfert : s'arracher à la suggestion du somatique
Authors: Villa François
Published: April 2012

Résumé Ce texte est né à la suite de la relecture de L’interprétation des rêves dans la nouvelle traduction des Œuvres complètes , le commentaire que Freud fait à propos du rêve où il figure montant un cheval gris mérite que nous lui portions attention. Par rapport à ce rêve qui est apparu sous la contrainte du stimulus douloureux que constituait un furoncle à la base du scrotum, Freud note que le rêve lui “désuggéra” le furoncle . Faut-il reconnaître dans cette formulation, l’esquisse d’une théorie sur l’une des fonctions du rêve, du traitement psychique : permettre de s’arracher à la suggestion que l’expérience vécue somatique exercerait ? N’est-ce pas là une voie d’entrée pour penser l’obscure notion de refoulement organique  ? Y a-t-il vraiment lieu de généraliser ce qui est formulé à l’occasion de ce rêve ? C’est cette éventualité qui est, ici examiné depuis la névrose de transfert.
Compétitivité et performances macroéconomiques en Allemagne : suivez le guide ?
Authors: Heylen Freddy , Buyse Tim
Published: April 2012

Résumé Dans cet article, nous décrivons et évaluons les performances macroéconomiques de l’Allemagne au cours de la décennie écoulée. Nous analysons la formation des salaires, la compétitivité et les performances à l’exportation. Nous nous demandons également dans quelle mesure le modèle allemand est performant au regard des défis à long terme posés par le vieillissement démographique et par le besoin de renforcer l’emploi et la croissance économique. Nous comparons l’Allemagne à plusieurs autres pays européens, parmi lesquels la Belgique et les pays scandinaves. Nous en concluons que le succès du modèle allemand est partiel. Le « pays-guide » ne convainc pas en certains points importants, comme les investissements dans le capital humain et la pleine exploitation du potentiel de main-d’œuvre. Code JEL : E23, E24, J2, O57
Les pôles de compétitivité : un nouvel instrument de la politique industrielle de la Wallonie
Authors: Bayenet Benoît , Capron Henri
Published: April 2012

Résumé Au cours de ces dix dernières années, nous avons assisté dans le monde entier à l’émergence de politiques de « clustering ». Les clusters étant des agglomérations spatiales d’industries et de services colocalisés, la dimension régionale joue un rôle déterminant dans l’élaboration des nouvelles politiques industrielles mises en œuvre par les pays européens et la Commission européenne. En 2005, la Wallonie a lancé une nouvelle politique industrielle axée sur la création de pôles de compétitivité. L’objectif consistait à mettre en réseau des entreprises, centres de recherche et établissements d’enseignement afin de stimuler la création de nouvelles richesses et de nouveaux emplois par le financement de projets innovants. À ce jour, les autorités wallonnes ont soutenu le développement de six pôles dans le cadre de la mise en œuvre des Plans Marshall et Marshall 2.vert. Le choix des pôles a été opéré sur la base d’un processus mixte combinant les approches ascendante et descendante. Le présent article a pour but de décrire la procédure mise en œuvre par les autorités wallonnes et d’examiner le positionnement européen des pôles wallons. Codes JEL : R58, R38, R11
Le rôle des services aux entreprises à forte intensité de connaissances dans la compétitivité belge : conseil et assistance aux entreprises
Authors: Renders Stephen , Sleuwaegen Leo
Published: April 2012

Résumé Au cours des dernières décennies, la part du secteur des services a considérablement augmenté dans les économies industrialisées. Bien que cette évolution soit souvent associée à la croissance plus faible de la productivité au sein de ce segment, on observe une croissance élevée des services hautement productifs et à forte intensité de connaissances. Nous expliquons l’importance croissante des services à forte intensité de connaissances pour la compétitivité au moyen d’une analyse détaillée du secteur belge des services de conseil et d’assistance aux entreprises. Nous examinons les principaux facteurs à la base de la forte croissance de ce segment en nous aidant du schéma d’analyse de Michael Porter. Nous en concluons que les services à forte intensité de connaissances, caractérisés par des effets de réseau considérables, remplissent un rôle central dans l’économie de la connaissance en stimulant le transfert intersectoriel du savoir, la flexibilité et la spécialisation.
Transforming the Journey for Newly Licensed Registered Nurses
Authors: Holland Cindra , Moddeman Gail R.
Published: April 2012

Newly licensed nurses entering into practice experience stressors related to daily challenges. This evidence-based practice project implemented a nurse residency program designed to ease the transition during the first year of practice. Newly licensed nurses at a Midwestern health care organization were enrolled in a yearlong nurse residency program and were required to attend one 4-hour session monthly. Program outcomes included a decrease in turnover and improved confidence.
The Use of an Advanced Medical-Surgical Course for the Retention and Professional Development of Medical-Surgical Nurses in an Acute Care Hospital
Authors: Gutekunst Marie-Claude , DeLucca Jeanine , Kessler Beth A.
Published: April 2012

The retention and professional development of the medical-surgical nurse is a challenging endeavor. Voluntary nurse turnover affects the collective costs of direct and indirect recruiting, productivity and training, and termination. These costs are estimated to be 0.75 to 1.30 times a nurse’s average departing salary. The multifactorial dimensions of nursing retention remain a challenge for leaders at the organizational level. This article describes an educational strategy in the form of an advanced medical-surgical course used by a multicampus academic community Magnet® hospital to increase the retention and professional development of medical-surgical nurses. The authors report the goals, content, and outcomes of this advanced medical-surgical course.
Two Teenage Males with Hypocalcemia and Elevated Parathyroid Hormone Levels
Authors: Shoemaker Ashley H. , Bremer Andrew A.
Published: April 2012

Vitamin D deficiency is not a rare disorder, particularly in minority groups. The Institute of Medicine recommends serum 25-hydroxyvitamin (OH)D levels >20 ng/mL and The Endocrine Society recommends levels >30 ng/mL for good health. In contrast, the 2003–2006 National Health and Nutrition Examination Survey reported average total 25-(OH)D concentrations of 25.6 ± 0.4 ng/mL in whites, 19.5 ± 0.5 ng/mL in Mexican Americans, and 14.8 ± 0.4 ng/mL in blacks. Pediatric patients with vitamin D deficiency may be asymptomatic or may present either with rickets, hypocalcemia, or seizures.

Pseudohypoparathyroidism (PHP) is a rare disorder characterized by parathyroid hormone (PTH) resistance with (type 1a) or without (type 1b) the Albright Hereditary Os-teodystrophy (AHO) phenotype of short stature, brachydactyly, and mental retardation. Patients with PHP have elevated PTH levels and may have hyperphosphatemia and hypocalcemia. However, the same laboratory values can be seen in children with vitamin D deficiency, and diagnostic confusion is common. We report two cases of vitamin D deficiency with presentations suggestive of PHP.
New Tool for Applying Traction During Open Reduction and Internal Fixation of Acetabular Fractures
Authors: Lien Fang-Chieh
Published: April 2012

Open reduction and internal fixation is used to treat complex acetabular fractures. Traction on the femur is necessary to reduce the acetabulum and is accomplished by surgical assistants or with mechanical devices. To overcome the disadvantages of various traction methods, the author designed a simple, novel traction device that can be used on an ordinary orthopedic or radiolucent operating table and has advantages over manual traction and commercial traction tables. The device consists of a horizontal cross-bar supported over the patient by 2 free-standing legs and is constructed from commercially available parts.
Preventing the Harm of a Closer Look: Contrast-induced Nephropathy in Adults
Authors: Holder Martina C. , Lewis Daniel A. , Winstead P. Shane
Published: April 2012

Contrast media is administered to many patients in hospitals nationwide. Although the use of contrast and dyes is widespread and has a well accepted use among the medical profession, contrast-induced nephropathy can be a common and potentially harmful complication. Identifying patients at risk, attempting to minimize risk, and using preventative strategies should be priorities to decrease the harmful effects that are associated with the administration of contrast media. This article provides a general overview of contrast-induced nephropathy and a brief review of the risk factors and prophylactic treatment.
Cam Morphology in the Human Hip
Authors: Ng Vincent Y. , Ellis Thomas J.
Published: April 2012

A growing interest exists in the diagnosis and treatment of femoroacetabular impingement. Although cam morphology of the proximal femur may conceptually appear to be a relatively simple topographical aberrancy, it is actually positioned amid a complex developmental, kinematic, and biomechanical region of the human body. The authors introduce a new classification scheme and review the historical and anthropological considerations, biomechanics, and genetic factors involved in cam morphology.
Effects of Pulsed Electromagnetic Field Frequencies on the Osteogenic Differentiation of Human Mesenchymal Stem Cells
Authors: Luo Fei , Hou Tianyong , Zhang Zehua , Xie Zhao , Wu Xuehui , Xu Jianzhong
Published: April 2012

The purpose of this study was to evaluate the effect of different frequencies of pulsed electromagnetic fields on the osteogenic differentiation of human mesenchymal stem cells. Third-generation human mesenchymal stem cells were irradiated with different frequencies of pulsed electromagnetic fields, including 5, 25, 50, 75, 100, and 150 Hz, with a field intensity of 1.1 mT, for 30 minutes per day for 21 days. Changes in human mesenchymal stem cell morphology were observed using phase contrast microscopy. Alkaline phosphatase activity and osteocalcin expression were also determined to evaluate human mesenchymal stem cell osteogenic differentiation.

Different effects were observed on human mesenchymal stem cell osteoblast induction following exposure to different pulsed electromagnetic field frequencies. Levels of human mesenchymal stem cell differentiation increased when the pulsed electromagnetic field frequency was increased from 5 hz to 50 hz, but the effect was weaker when the pulsed electromagnetic field frequency was increased from 50 Hz to 150 hz. The most significant effect on human mesenchymal stem cell differentiation was observed at of 50 hz.

The results of the current study show that pulsed electromagnetic field frequency is an important factor with regard to the induction of human mesenchymal stem cell differentiation. Furthermore, a pulsed electromagnetic field frequency of 50 Hz was the most effective at inducing human mesenchymal stem cell osteoblast differentiation in vitro.
Trends in the Orthopedic Job Market and the Importance of Fellowship Subspecialty Training
Authors: Morrell Nathan T. , Mercer Deana M. , Moneim Moheb S.
Published: April 2012

Previous studies have examined possible incentives for pursuing orthopedic fellowship training, but we are unaware of previously published studies reporting the trends in the orthopedic job market since the acceptance of certain criteria for fellowship programs by the Accreditation Council for Graduate Medical Education (ACGME) in 1985. We hypothesized that, since the initiation of accredited postresidency fellowship programs, job opportunities for fellowship-trained orthopedic surgeons have increased and job opportunities for nonfellowship-trained orthopedic surgeons have decreased. We reviewed the job advertisements printed in the
Journal of Bone and Joint Surgery, American Volume
, for the years 1984, 1994, 2004, and 2009. We categorized the job opportunities as available for either a general (nonfellowship-trained) orthopedic surgeon or a fellowship-trained orthopedic surgeon. Based on the advertisements posted in the
Journal of Bone and Joint Surgery, American Volume
, a trend exists in the orthopedic job market toward seeking fellowship-trained orthopedic surgeons. In the years 1984, 1994, 2004, and 2009, the percentage of job opportunities seeking fellowship-trained orthopedic surgeons was 16.7% (95% confidence interval [CI], 13.1%–20.3%), 40.6% (95% CI, 38.1%–43.1%), 52.2% (95% CI, 48.5%–55.9%), and 68.2% (95% CI, 65.0%–71.4%), respectively. These differences were statistically significant (analysis of variance,
P
<.05). Fellowship training is thus a worthwhile endeavor.
Heat Generated With Pegged or Keeled Glenoid Components Fixed With Defined Amounts of Cement
Authors: Martens Kelly A. , Edwards Sara L. , Omar Imran M. , Saltzman Matthew D.
Published: April 2012

Glenoid component loosening is a common complication of total shoulder arthroplasty and has been associated with the progression of radiolucent lines at the glenoid bone–cement interface. Generation of heat during the exothermic reaction of cement curing may cause osteonecrosis of bone, potentially leading to the development of radiolucent lines. The purpose of this study was to measure the heat generated with various defined amounts of cement used for glenoid component fixation.

Ten fresh-frozen cadaver scapulas were randomized to receive a keeled or pegged component with 1, 2, 3, 5, or 7 g of cement for fixation. An infrared camera was used to record the surface temperature generated during the cement curing process to an accuracy of ±2.0°C. Computed tomography was used to evaluate the cement mantle. The maximum temperatures generated did not exceed the critical value for osteonecrosis (56°C) in any of the specimens. The 4 specimens without a complete mantle were those fixed with a smaller quantity of cement (1, 2, or 3 g), and the largest cement mantle thicknesses were observed with the use of 7 g of cement.

Up to 7 g of cement can be used without significant concern for thermal necrosis. Incomplete cement mantles were observed when ⩽3 g of cement was used for fixation. Our results suggest that surgeons should use >3 g of cement to avoid incomplete cement mantles and that up to 7 g of cement can safely be used for glenoid fixation.
Arthroscopic Pancapsular Plication for Multidirectional Shoulder Instability in Overhead Athletes
Authors: Ma Hsiao-Li , Huang Hui-Kuang , Chiang En-Rung , Wang Shih-Tein , Hung Shih-Chieh , Liu Chein-Lin
Published: April 2012

Treating shoulder multidirectional instability with an open stabilization procedure has been reported to have good results. However, few studies exist of arthroscopic plication, especially in overhead athletes. The purpose of this study was to evaluate the clinical outcomes of arthroscopic pancapsular plication for multidirectional instability in overhead athletes.

Twenty-three athletes with symptomatic multidirectional instability were treated with arthroscopic pancapsular plication and evaluated at a mean follow-up of 36.3 months (range, 24–61 months). Mean patient age was 23.3 years (range, 19–33 years). Functional outcomes were evaluated with the American Shoulder and Elbow Surgeons (ASES) score, Constant shoulder score, and Rowe instability score. The degree of pain and range of motion were also recorded. All postoperative functional scores were rated good to excellent, with an average ASES score of 88.4 (range, 82–95), average Constant shoulder score of 88.1 (range, 81–100), and average Rowe instability score of 86.7 (range, 80–100). Five patients returned to the same level of competitive sports, and 18 returned to a limited level. All patients were satisfied with the stability postoperatively. No significant change was observed in postoperative range of motion, but patients who returned to a limited level of sports had lower functional scores and more pain than did those who fully returned to sports.

Arthroscopic pancapsular plication for treating multidirectional instability in overhead athletes can provide good stability. However, the low rate of return to a full level of overhead sports is a problem. Further evaluation of the benefits of this procedure for overhead athletes with symptomatic multidirectional instability is needed.
Matrix Metalloproteinase Levels as a Marker for Rotator Cuff Tears
Authors: Jacob Jinny , Eisemon Eric , Sheibani-Rad Shahin , Patel Archit , Jacob Theresa , Houeka Jackc
Published: April 2012

Although many studies report the role of matrix metalloproteinases (MMPs) in rotator cuff tears, a paucity of data exists correlating the clinical severity of the disease with the implicated MMP levels. The purpose of this study was to investigate and compare the levels of expression of MMP-1, -3, -9 and -13 in patients with rotator cuff tears. We hypothesized that patients with clinically worse symptoms as measured by a standardized pain and function scale would have a higher expression of MMPs.

Rotator cuff specimens were obtained from 16 consecutive patients undergoing rotator cuff repair. Total protein was extracted from these specimens and quantified. Equalized total protein extracts were used for performing enzyme-linked immunosorbent assay for quantitative determination of MMP-1, -3, -9 and -13. Preoperatively, the University of California, Los Angeles (UCLA) Shoulder Rating Scale was administered to each patient. Statistical comparisons were performed using analysis of variance. The expression of MMP-13 was notably increased in the rotator cuff extracts of all patients (
P
=.02). In addition, MMP-13 levels showed a significant proportional correlation with the patient pain score as per their UCLA ratings (
r
=–0.5). Although higher MMP-9 levels were assayed, this was not statistically significant. Expression of MMP-1 and-3 was insignificant.

Our data suggest a critical role for MMP-13 in rotator cuff tears; elevated levels are a possible indicator for an impending tear. Further studies with increased sample size are warranted to prove the possible use of MMP-13 as therapeutic targets that may be inhibited by anti-inflammatory agents to limit disease progression.
Characterization of Daptomycin-loaded Antibiotic Cement
Authors: Kaplan Lige , Kurdziel Michael , Baker Kevin C. , Verner James
Published: April 2012

Antibiotics are commonly mixed with polymethylmethacrylate (PMMA) cement to suppress severe periprosthetic infections associated with total joint arthroplasty. The relationship between antibiotic concentration and the resulting elution kinetics remains unclear. The purpose of this study was to characterize the release of daptomycin from PMMA cement and the subsequent effects on mechanical properties.

Varying concentrations of daptomycin and tobramycin were vacuum mixed in commercially available PMMA and subjected to an in vitro elution period. High-performance liquid chromatography was used to quantify the concentration of the amount of daptomycin eluted at predetermined time points. Samples were subjected to compressive loading to analyze the effect of antibiotic concentration on cement mechanical properties. Daptomycin elution increased when initial tobramycin concentration was increased. Furthermore, the addition of antibiotics increased the compressive strength of the cement in the postelution period. The binary addition of tobramycin with daptomycin antibiotics modifies the elution and mechanical properties of PMMA bone cement. Based on the findings of our study, 2 g of daptomycin and 3.6 g of tobramycin per 40-g packet of cement should be used to promote daptomycin elution without sacrificing PMMA mechanical properties.
Nonoperative Treatment of Displaced Type II Odontoid Peg Fractures With a Philadelphia Collar
Authors: Singh Vinay , Banerjee Samik , Onukaogu Smart , Singh Pankaj , Leitao James
Published: April 2012

Although a consensus exists on the nonoperative management of types I and III odontoid peg fractures, treatment of type II fractures remains controversial. An increasing trend exists toward primary fixation of type II peg fractures due to a high rate of nonunion, especially if the displacement is >4 mm. This article reports the results of nonoperative treatment of patients with displaced odontoid peg fractures (>4 mm) using a Philadelphia collar.

A retrospective review of clinical and radiological records was performed for nonoperatively treated patients who sustained displaced type II peg fractures between January 2003 and April 2008. The study group comprised 9 patients (2 men and 7 women), and all patients were treated with Philadelphia collars. Patients were followed up for an average of 24.8 months (range, 8–28 months) for clinical and radiological outcomes. Functional outcomes were measured according to the Smiley-Webster scale. Fractures united uneventfully in 6 patients, but nonunion developed in 3 patients. Average time to union was 12.3±2.94 weeks (95% confidence interval, 9.97–14.68 weeks; range, 10–16 weeks). No patient had clinical or radiological signs of instability or delayed onset myelopathy at follow-up. Three patients had excellent, 4 had good, and 2 had fair results as per the Smiley-Webster functional scoring system.

Displaced type II peg fractures can be managed nonoperatively in patients who refuse surgery or those with multiple comorbidities. Adequate patient counseling and compliance with close clinicoradiological follow-up is paramount to avoid adverse clinical events and achieve an optimal functional outcome.
Bilateral Anatomic Total Shoulder Arthroplasty Versus Reverse Shoulder Arthroplasty
Authors: Latif Vaqar , Denard Patrick J. , Young Allan A. , Liotard Jean-Pierre , Walch Gllies
Published: April 2012

The results of anatomic total shoulder arthroplasty and reverse shoulder arthroplasty have previously been reported separately. Although the indications differ, scenarios exist in which a patient may have a total shoulder arthroplasty on 1 shoulder and a reverse shoulder arthroplasty on the contralateral shoulder.

Between 1992 and 2009, twelve patients underwent bilateral sequential primary shoulder arthroplasty with a total shoulder arthroplasty on 1 side and reverse shoulder arthroplasty on the contralateral side. Constant score, American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, and patient satisfaction were obtained a minimum 1 year postoperatively. Mean postoperative Constant score was 77 after total shoulder arthroplasty and 73 after reverse shoulder arthroplasty (
P
<.2488). Mean postoperative active forward flexion was similar after total shoulder arthroplasty compared with reverse shoulder arthroplasty (
P
=.8910). Greater external rotation at the side (43° vs 12°;
P
<.0001) and internal rotation (T8 vs L1;
P
<.0001) were observed after total shoulder arthroplasty. Mean ASES score was 89.6 after total shoulder arthroplasty compared with 82.4 after reverse shoulder arthroplasty (
P
=.0125). Patient satisfaction was 92% for both prostheses, and mean subjective shoulder value was similar (85.4% vs 82.5%;
P
=.6333).

Bilateral shoulder arthroplasty performed with a total shoulder arthroplasty and reverse shoulder arthroplasty on opposite shoulders can provide good functional outcome and high patient satisfaction. Although range of motion is better following total shoulder arthroplasty, no difference was observed in final Constant score or subjective patient assessment.
Rate of Adverse Reactions to More Than 1 Series of Viscosupplementation
Authors: Webber Tracy A. , Webber Anthony E. , Matzkin Elizabeth
Published: April 2012

Viscosupplementation, hyaluronic acid treatment, is an ancillary method for treating patients with symptomatic stage I or II osteoarthritis. Previous studies reported that local reactions occurred more frequently in patients receiving >1 course of treatment compared with patients receiving their first course of treatment. One (2%) of 42 first series patients and 4 (21%) of 19 of repeated series patients had adverse reactions severe enough to seek unscheduled care.

This study was performed to determine whether patients receiving >1 series of viscosupplementation had an increased adverse reaction rate. A retrospective chart review was performed on all patients who received >1 series of viscosupplementation during the study. A local adverse reaction was defined as acute swelling and pain in the knee, with no injury or trauma within 72 hours after hyaluronic acid injection.

Twenty-eight knees received >1 series of viscosupplementation. The adverse reaction rate to second series injections was 1.28% (3.57% of knees). The adverse reaction rate to ⩾3 series was 0.9% (6.67% of knees). This adverse reaction rate was significantly less than the 21% reported in previous studies for multiple series injections (
z
=−1.90;
P
<.05) and is not significantly different than the 2% rate of adverse reactions reported for first series injections. No significant difference existed in the adverse reaction rates between 2 series and ⩾3 series of viscosupplementation.

The current study suggests that the rate of adverse reaction was low at 1.28% of second series viscosupplementation.
Late Liner Disassociation of a Pinnacle System Acetabular Component
Authors: Mayer Stephanie W. , Wellman Samuel S. , Bolognesi Michael P. , Attarian David E.
Published: April 2012

This article describes a case of late locking mechanism failure and disassociation of a Pinnacle acetabular cup (DePuy, Warsaw, Indiana) and Marathon polyethylene liner (DePuy) 53 months after routine primary total hip arthroplasty in an active patient. Following an uncomplicated initial postoperative recovery, the patient felt a pop while kneeling for gardening activities. The patient had no prodromal symptoms but reported pain with range of motion and weight bearing following the episode. Radiographs appeared to show a fractured liner with intact acetabular and femoral components. Intraoperatively, the liner was disassociated and dislocated inferior to the acetabulum, and 3 consecutive antirotational tines were sheared off the liner at their bases. The acetabular cup and femoral stem were well fixed. Extensive metallosis existed from the femoral head and acetabular shell articulating in the absence of a liner. The patient underwent revision of the acetabular cup, polyethylene liner, and femoral head due to the concern for osteolysis given the extensive metallosis. Revision of the acetabular cup and liner were performed with no further complications. No conclusions could be made as to the exact mechanism of failure following laboratory analysis of the retrieved polyethylene liner. Several possible mechanisms of failure are possible. Although cases of acute disassociation of this system have been reported, this is the first article to our knowledge to report failure at such a late postoperative time.