bluuebunny/crossref_metadata_2025 huggingface dataset:
Work participation and health status in early osteoarthritis of the hip and/or knee: A comparison between the cohort hip and cohort knee and the osteoarthritis initiative
Authors: Bieleman H. J. , Oosterveld F. G. J. , Oostveen J. C. M. , Reneman M. F. , Groothoff J. W.
Published: January 2010

Objective

To examine the work participation of Dutch people with early osteoarthritis (OA) in hips or knees and compare this with data from the American Osteoarthritis Initiative (OAI) cohort. The influence of health status and personal factors on work participation was analyzed.

Methods

In the Cohort Hip and Cohort Knee (CHECK) study, 1,002 subjects were included. Baseline questionnaire data from 970 subjects were analyzed. Rate ratios were calculated to compare work participation with the general Dutch population, after correcting (by stratifying) for age, sex, and education. Health status was measured using the Short Form 36 health survey and the Western Ontario and McMaster Universities Osteoarthritis Index. Groups were compared (CHECK versus OAI, workers versus nonworkers) using t‐tests.

Results

The mean age of the subjects was 56 years and 79% were women. Overall participation was 51%, similar to the general Dutch population and lower than in the OAI (76%). Point prevalence of sick leave because of hip/knee symptoms was 2%, and year prevalence was 12%. Of the subjects, 14% had made work adaptations. Workers reported significantly better health status (corrected for age, sex, and education) than nonworkers.

Conclusion

Work participation of Dutch people with early OA is similar to the general population and significantly lower than American subjects. Increasing age, female sex, and lower education level were related to lower participation. Societal factors appear to have had more effect on work participation than health status in this stage of OA. The better health status of workers could not be explained solely by selection bias, but may be a result of work.
Association between physical exercise, body mass index, and risk of fibromyalgia: Longitudinal data from the Norwegian Nord‐Trøndelag Health Study
Authors: Mork Paul J. , Vasseljen Ottar , Nilsen Tom I. L.
Published: January 2010

Objective

To examine the association between leisure time physical exercise, body mass index (BMI), and risk of fibromyalgia (FM).

Methods

A longitudinal study with baseline assessment of physical exercise (frequency, duration, and intensity) and BMI was used to explore the risk of having FM at 11‐year followup in a large, unselected female population (n = 15,990) without FM or physical impairments at baseline.

Results

At followup, 380 cases of incident FM were reported. A weak dose‐response association was found between level of physical exercise and risk of FM (for trend, P = 0.13) where women who reported the highest exercise level had a relative risk (RR) of 0.77 (95% confidence interval [95% CI] 0.55–1.07). BMI was an independent risk factor for FM (for trend, P < 0.001), and overweight or obese women (BMI ≥25.0 kg/m2) had a 60–70% higher risk compared with women with normal weight (BMI 18.5–24.9 kg/m2). Overweight or obese women who exercised ≥1 hour per week had an RR of 1.72 (95% CI 1.07–2.76) compared with normal‐weight women with a similar activity level, whereas the risk was >2‐fold higher for overweight or obese women who were either inactive (RR 2.09, 95% CI 1.36–3.21) or exercised <1 hour per week (RR 2.19, 95% CI 1.39–3.46).

Conclusion

Being overweight or obese was associated with an increased risk of FM, especially among women who also reported low levels of physical exercise. Community‐based measures aimed at reducing the incidence of FM should emphasize the importance of regular exercise and the maintenance of normal body weight.
SirT1 enhances survival of human osteoarthritic chondrocytes by repressing protein tyrosine phosphatase 1B and activating the insulin‐like growth factor receptor pathway
Authors: Gagarina Viktoria , Gabay Odile , Dvir‐Ginzberg Mona , Lee Eun Jin , Brady Jillian K. , Quon Michael J. , Hall David J.
Published: January 2010

Objective

The protein deacetylase SirT1 inhibits apoptosis in a variety of cell systems by distinct mechanisms, yet its role in chondrocyte death has not been explored. We undertook the present study to assess the role of SirT1 in the survival of osteoarthritic (OA) chondrocytes in humans.

Methods

SirT1, protein tyrosine phosphatase 1B (PTP1B), and PTP1B mutant expression plasmids as well as SirT1 small interfering RNA (siRNA) and PTP1B siRNA were transfected into primary human chondrocytes. Levels of apoptosis were determined using flow cytometry, and activation of components of the insulin‐like growth factor receptor (IGFR)/Akt pathway was assessed using immunoblotting. OA and normal knee cartilage samples were subjected to immunohistochemical analysis.

Results

Expression of SirT1 in chondrocytes led to increased chondrocyte survival in either the presence or the absence of tumor necrosis factor α/actinomycin D, while a reduction of SirT1 by siRNA led to increased chondrocyte apoptosis. Expression of SirT1 in chondrocytes led to activation of IGFR and the downstream kinases phosphatidylinositol 3‐kinase, phosphoinosite‐dependent protein kinase 1, mTOR, and Akt, which in turn phosphorylated MDM2, inhibited p53, and blocked apoptosis. Activation of IGFR occurs at least in part via SirT1‐mediated repression of PTP1B. Expression of PTP1B in chondrocytes increased apoptosis and reduced IGFR phosphorylation, while down‐regulation of PTP1B by siRNA significantly decreased apoptosis. Examination of cartilage from normal donors and OA patients revealed that PTP1B levels are elevated in OA cartilage in which SirT1 levels are decreased.

Conclusion

For the first time, it has been demonstrated that SirT1 is a mediator of human chondrocyte survival via down‐regulation of PTP1B, a potent proapoptotic protein that is elevated in OA cartilage.
High‐dose cyclophosphamide versus monthly intravenous cyclophosphamide for systemic lupus erythematosus: A prospective randomized trial
Authors: Petri Michelle , Brodsky Robert A. , Jones Richard J. , Gladstone Douglas , Fillius Michael , Magder Laurence S.
Published: January 2010

Objective

Monthly intravenous (IV) cyclophosphamide for 6 months has been the standard induction regimen for lupus nephritis, followed by a maintenance regimen of quarterly infusions for 2 years. We undertook this study to compare the efficacy and safety of the standard regimen versus a high‐dose IV cyclophosphamide regimen.

Methods

We performed a prospective randomized trial comparing monthly IV cyclophosphamide at 750 mg/m2 body surface area for 6 months followed by quarterly IV cyclophosphamide for 2 years (traditional treatment) against high‐dose IV cyclophosphamide (50 mg/kg daily for 4 days) (high‐dose treatment). Entry criteria included renal lupus, neurologic lupus, or other organ system involvement with moderate‐to‐severe activity.

Results

Fifty‐one patients were randomized; 3 withdrew before treatment and 1 committed suicide after 2 months of high‐dose treatment. Twenty‐two had renal lupus, 14 had neurologic lupus, and 11 had other organ involvement. The outcome measure was the Responder Index for Lupus Erythematosus (complete response, partial response, no change, or worsening). At 6 months (the end of induction), 11 of 21 patients (52%) in the high‐dose treatment group had a complete response compared with 9 of 26 patients (35%) in the traditional treatment group (P = 0.13). At the final visit (30 months), 10 of 21 patients (48%) in the high‐dose treatment group had a complete response compared with 13 of 20 patients (65%) who continued with traditional treatment (P = 0.13). Six patients crossed over from traditional treatment to high‐dose treatment because of lack of response, and 3 of those patients became complete responders.

Conclusion

There was not strong evidence that monthly IV cyclophosphamide and high‐dose IV cyclophosphamide differed in complete or in any (complete or partial) response to induction or maintenance therapy. However, nonresponders to monthly IV cyclophosphamide can sometimes be rescued with high‐dose IV cyclophosphamide.
Text‐based video content classification for online video‐sharing sites
Authors: Huang Chunneng , Fu Tianjun , Chen Hsinchun
Published: January 2010

With the emergence of Web 2.0, sharing personal content, communicating ideas, and interacting with other online users in Web 2.0 communities have become daily routines for online users. User‐generated data from Web 2.0 sites provide rich personal information (e.g., personal preferences and interests) and can be utilized to obtain insight about cyber communities and their social networks. Many studies have focused on leveraging user‐generated information to analyze blogs and forums, but few studies have applied this approach to video‐sharing Web sites. In this study, we propose a text‐based framework for video content classification of online‐video sharing Web sites. Different types of user‐generated data (e.g., titles, descriptions, and comments) were used as proxies for online videos, and three types of text features (lexical, syntactic, and content‐specific features) were extracted. Three feature‐based classification techniques (C4.5, Naïve Bayes, and Support Vector Machine) were used to classify videos. To evaluate the proposed framework, user‐generated data from candidate videos, which were identified by searching user‐given keywords on YouTube, were first collected. Then, a subset of the collected data was randomly selected and manually tagged by users as our experiment data. The experimental results showed that the proposed approach was able to classify online videos based on users' interests with accuracy rates up to 87.2%, and all three types of text features contributed to discriminating videos. Support Vector Machine outperformed C4.5 and Naïve Bayes techniques in our experiments. In addition, our case study further demonstrated that accurate video‐classification results are very useful for identifying implicit cyber communities on video‐sharing Web sites.
Probing protein colloidal behavior in membrane‐based separation processes using spectrofluorometric Rayleigh scattering data
Authors: Elshereef Rand , Budman Hector , Moresoli Christine , Legge Raymond L.
Published: January 2010

One of the primary problems in membrane‐based protein separation is membrane fouling. In this study we explored the feasibility of employing Rayleigh light scattering data from fluorescence studies combined with chemometric techniques to determine whether a correlation could be established with membrane fouling phenomena. Membrane flux was measured in a dead‐end UF filtration system and the effect of protein solution properties on the flux decline was systematically investigated. A variety of proteins were used as a test case in this study. In parallel, the colloidal behavior of the protein solutions was assessed by employing multiwavelength Rayleigh scattering measurements. To assess the usefulness of Rayleigh scattering measurements for probing the colloidal behavior of proteins, a protein solution of β‐lactoglobulin was used as a base‐case scenario. The colloidal behavior of different β‐lactoglobulin solutions was inferred based on published data for this protein, under identical solution conditions, where techniques other than Rayleigh scattering had been used. Using this approach, good agreement was observed between scattering data and the colloidal behavior of this protein. To test the hypothesis that a high degree of aggregation will lead to increased membrane fouling, filtration data was used to find whether the Rayleigh scattering intensity correlated with permeate flux changes. It was found that for protein solutions which were stable and did not aggregate, fouling was reduced and these solutions exhibited reduced Rayleigh scattering. When the aggregation behavior of the solution was favored, significant flux declines occurred and were highly correlated with increased Rayleigh scattering. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Strategies for developing design spaces for viral clearance by anion exchange chromatography during monoclonal antibody production
Authors: Strauss Daniel M. , Cano Tony , Cai Nick , Delucchi Heather , Plancarte Magdalena , Coleman Daniel , Blank Gregory S. , Chen Qi , Yang Bin
Published: January 2010

The quality‐by‐design (QbD) regulatory initiative promotes the development of process design spaces describing the multidimensional effects and interactions of process variables on critical quality attributes of therapeutic products. However, because of the complex nature of production processes, strategies must be devised to provide for design space development with reasonable allocation of resources while maintaining highly dependable results. Here, we discuss strategies for the determination of design spaces for viral clearance by anion exchange chromatography (AEX) during purification of monoclonal antibodies. We developed a risk assessment for AEX using a formalized method and applying previous knowledge of the effects of certain variables and the mechanism of action for virus removal by this process. We then use design‐of‐experiments (DOE) concepts to perform a highly fractionated factorial experiment and show that varying many process parameters simultaneously over wide ranges does not affect the ability of the AEX process to remove endogenous retrovirus‐like particles from CHO‐cell derived feedstocks. Finally, we performed a full factorial design and observed that a high degree of viral clearance was obtained for three different model viruses when the most significant process parameters were varied over ranges relevant to typical manufacturing processes. These experiments indicate the robust nature of viral clearance by the AEX process as well as the design space where removal of viral impurities and contaminants can be assured. In addition, the concepts and methodology presented here provides a general approach for the development of design spaces to assure that quality of biotherapeutic products is maintained. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
A rotating bed system bioreactor enables cultivation of primary osteoblasts on well‐characterized sponceram® regarding structural and flow properties
Authors: Suck Kirstin , Roeker Stefanie , Diederichs Solvig , Anton Fabienne , Sanz‐Herrera Jose A. , Ochoa Ignacio , Doblare Manuel , Scheper Thomas , van Griensven Martijn , Kasper Cornelia
Published: January 2010

The development of bone tissue engineering depends on the availability of suitable biomaterials, a well‐defined and controlled bioreactor system, and on the use of adequate cells. The biomaterial must fulfill chemical, biological, and mechanical requirements. Besides biocompatibility, the structural and flow characteristics of the biomaterial are of utmost importance for a successful dynamic cultivation of osteoblasts, since fluid percolation within the microstructure must be assured to supply to cells nutrients and waste removal. Therefore, the biomaterial must consist of a three‐dimensional structure, exhibit high porosity and present an interconnected porous network. Sponceram®, a ZrO2 based porous ceramic, is characterized in the presented work with regard to its microstructural design. Intrinsic permeability is obtained through a standard Darcy's experiment, while Young's modulus is derived from a two plates stress–strain test in the linear range. Furthermore, the material is applied for the dynamic cultivation of primary osteoblasts in a newly developed rotating bed bioreactor. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Theoretical Studies on the Intermolecular Interactions of Potentially Primordial Base‐Pair Analogues
Authors: Šponer Judit E. , Vázquez‐Mayagoitia Álvaro , Sumpter Bobby G. , Leszczynski Jerzy , Šponer Jiří , Otyepka Michal , Banáš Pavel , Fuentes‐Cabrera Miguel
Published: January 2010

Recent experimental studies on the Watson–Crick type base pairing of triazine and aminopyrimidine derivatives suggest that acid/base properties of the constituent bases might be related to the duplex stabilities measured in solution. Herein we use high‐level quantum chemical calculations and molecular dynamics simulations to evaluate the base pairing and stacking interactions of seven selected base pairs, which are common in that they are stabilized by two NH⋅⋅⋅O hydrogen bonds separated by one NH⋅⋅⋅N hydrogen bond. We show that neither the base pairing nor the base stacking interaction energies correlate with the reported pKa data of the bases and the melting points of the duplexes. This suggests that the experimentally observed correlation between the melting point data of the duplexes and the pKa values of the constituent bases is not rooted in the intrinsic base pairing and stacking properties. The physical chemistry origin of the observed experimental correlation thus remains unexplained and requires further investigations. In addition, since our calculations are carried out with extrapolation to the complete basis set of atomic orbitals and with inclusion of higher electron correlation effects, they provide reference data for stacking and base pairing energies of non‐natural bases.
Iron‐ and Cobalt‐Catalyzed Asymmetric Hydrosilylation of Ketones and Enones with Bis(oxazolinylphenyl)amine Ligands
Authors: Inagaki Tomohiko , Phong Le Thanh , Furuta Akihiro , Ito Jun‐ichi , Nishiyama Hisao
Published: January 2010

Chiral bis(oxazolinylphenyl)amines proved to be efficient auxiliary ligands for iron and cobalt catalysts with high activity for asymmetric hydrosilylation of ketones and asymmetric conjugate hydrosilylation of enones.
Numerical simulation of thermal and mass transport during Czochralski crystal growth of sapphire
Authors: Lu Chung‐Wei , Chen Jyh‐Chen
Published: January 2010

The thermal and flow transport in an inductively heated Czochralski crystal growth furnace during a crystal growth process is investigated numerically. The temperature and flow fields inside the furnace, coupled with the heat generation in the iridium crucible induced by the electromagnetic field generated by the RF coil, are computed. The results indicate that for an RF coil fixed in position during the growth process, although the maximum value of the magnetic, temperature and velocity fields decrease, the convexity of the crystal‐melt interface increases for longer crystal growth lengths. The convexity of the crystal‐melt interface and the power consumption can be reduced by adjusting the relative position between the crucible and the induction coil during growth. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of reduction/oxidation treatment on blue photorefraction in In:Fe:Cu:LiNbO3 crystals
Authors: Luo Suhua , Wu Fengjiang , Wang Jian , Sun Xiudong
Published: January 2010

In:Fe:Cu:LiNbO3 crystals with reduced/oxidized treatments were prepared by the Czochralski method. The defect structure was analyzed by the UV‐Visible absorption spectra. The blue photorefractive properties, such as the refractive index change, response time, recording sensitivity, dynamic range as well as two‐wave coupling gain coefficient, were also investigated at 488 nm wavelength using the two‐wave coupling experiment. Comparing the as‐grown and oxidized In:Fe:Cu:LiNbO3 crystals, the reduced sample has the highest recording sensitivity and largest dynamic range. Meanwhile, the high diffraction efficiency is still maintained. Experimental results definitely show that reduction treatment is an effective method to improve the blue photorefractive performance of In:Fe:Cu:LiNbO3 crystals. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rapid synthesis of dendrite‐ and platelet‐like α‐Fe2O3 via a hydrothermal oxidation route
Authors: Liang Jun , Li Li , Song Weiming , Fang Junzhuo , Luo Min , Li Yanping
Published: January 2010

Dendrite and platelet‐like α‐Fe2O3 microcrystals were synthesized by the oxidation reaction of K4Fe(CN)6and NaClO3 through a simple hydrothermal method. The structures and morphologies of the as‐prepared samples were characterized in detail by X‐ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The experiment results show that NaOH played an important role in controlling the morphology of the final products. The possible mechanism was discussed to elucidate the formation of different morphologies of the α‐Fe2O3 microstructures. Besides, the magnetic property of the dendrite α‐Fe2O3 microstructure was characterized by a vibrating sample magnetometer (VSM). (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of forced solution flow on lysozyme crystal growth
Authors: Yu Yong , Liu Yuhong , Wang Xuan , Oberthür D. , Dierks K. , Betzel C.
Published: January 2010

In order to study quantitatively the effects of forced solution on crystal growth, we designed a new set of experimental equipment, in particular, a microchannel mixer was used as crystallization container so that the consumption of protein samples was much reduced and thus an exact syringe pump could be used for precise control of the flow rates. Since the mixer's section was designed to be rectangular, the solution velocity in its center was steady and constant, and thus repeatable experiments were facilitated. Experimental results showed that the effects of forced solution on protein crystal growth were different under different levels of supersaturation, and new results were obtained for cases of high supersaturation. When the supersaturation is σ = 2.3, with increasing flow rates the growth rates of the lysozyme crystal's (110) face hardly change when the flow rates are lower than 1300 μm/s, and decrease quickly afterwards. When the flow rate reaches 2000 μm/s, the crystal nearly ceases to grow. When the supersaturation is σ = 2.7, with increasing flow rates the (110) face growth rates increase at the beginning then reach the maximum values at 1700 μm/s – 1900 μm/s and decrease afterwards, approaching zero or so when the flow rate reaches 12000 μm/s. The higher the supersaturation, the larger the flow rate at which the crystal ceases to grow. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and crystallographic characterization of crystalline modifications of 3,4:9,10‐perylenetetracarboxylic dianhydride at room temperature
Authors: Levin A. A. , Leisegang T. , Forker R. , Koch M. , Meyer D. C. , Fritz T.
Published: January 2010

3,4:9,10‐Perylenetetracarboxylic dianhydride (PTCDA) powder obtained from Sigma‐Aldrich was purified by three cycles of temperature gradient sublimation in an evacuated quartz glass tube providing variable conditions. By means of X‐ray diffraction (XRD) analysis, a crystallographic characterization of the powders obtained during the sublimation process and selected single crystals was carried out evidencing the presence of a major α‐ and a minor β‐PTCDA component in all samples. Lattice parameters of high precision were obtained for α‐PTCDA (a = 3.73283(4) Å, b = 12.0328(6) Å, c = 17.3998(4) Å, β = 98.689(2)°, V = 772.57(4) Å3 and d102 = 3.219(3) Å) by whole‐X‐ray‐powder‐pattern‐fitting of the experimental XRD pattern using the Le Bail approach. Employing a (001) KCl wafer as substrate for the material purification results in formation of single phase α‐PTCDA accompanied by a decrease in the size of the crystallites which is attributed to the presumed lower temperature of the KCl wafers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization and solventless growth of salicylic acid macro‐crystals involving a nitrogen gas flow
Authors: Menaa B. , Takahashi M. , Tokuda Y. , Yoko T.
Published: January 2010

We report an original solventless thermal crystallisation method to grow large needle‐like salicylic acid (SA) crystals of 10‐12 mm in length. The method is based on the utilization of nitrogen gaz flow on salicylic acid powder during heating just below melting point temperature for 24 h. Salicylic acid provides one of the best examples of a pharmaceutical substance used for cosmetics whose physical and chemical properties indicate hydrogen‐bond formation between the hydroxyl group and an adjacent oxygen atom of the same molecule. The structure of the crystals is confirmed by single crystal X‐ray diffraction; it is monoclinic, a = 4.93(2) Å, b = 11.23(5) Å, c = 11.56(6) Å, β = 90.77(4)° with the space group P 21/c. The macrocrystals formation using this method is new and represents an interesting finding for a wide range of applications to be developed in the fields of biotechnology and photonics (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural, optical and photoconductive properties of electron beam evaporated CdSxSe1‐x films
Authors: Sivaramamoorthy K. , Asath Bahadur S. , Kottaisamy M. , Murali K. R.
Published: January 2010

CdSxSe1‐x films were deposited by the electron beam evaporation technique on glass substrates at different temperatures in the range 30 – 300 °C using the laboratory synthesized powders of different composition. The films exhibited hexagonal structure and the lattice parameters shifted from CdSe to CdS side as the composition changed from CdSe to CdS side. The bandgap of the films increased from 1.68 to 2.41 eV as the concentration of CdS increased. The root‐mean‐roughness (RMS) values are 3.4, 2.6, 1.2 and 0.6 nm as the composition of the films shifted towards CdS side. The conductivity varies from 30 Ωcm‐1 to 480 Ωcm‐1 as the ‘x’ value increases from 0 to 1. The films exhibited photosensitivity. The PL spectrum shifts towards lower energies with decreasing x, due to the decrease of the fundamental gap with Se composition. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic Studies Directed Towards Various Homologues of Natural Sesquiterpene‐Coumarin Ethers: The Domino Approach
Authors: Corbu Andrei , Castro Juan M. , Aquino Maurizio , Gandara Zoila , Retailleau Pascal , Arseniyadis Siméon
Published: January 2010

A domino‐based strategy was used to construct analogues containing the basic skeleton of the monocyclic sesquiterpene‐coumarin ethers galbanic acid (1) and secodrial (3), through conversion of the domino adduct 19 into 10 and 11, chosen as representative targets. 1H NMR patterns, corroborated by X‐ray crystallographic analysis for two of the four possible diastereomeric arrangements of the six‐membered B‐ring common to various A‐seco terpenes, have been determined. The observed trends help in the design of substituent combinations that provide a tool for diastereomeric recognition, depending on the cis/trans arrangement of the adjacent methyl groups and the adopted conformations.
Development of a capillary gel electrophoresis method for monitoring disulfide isomer heterogeneity in IgG2 antibodies
Authors: Lacher Nathan A. , Wang Qian , Roberts Rachel K. , Holovics Heidi J. , Aykent Serdar , Schlittler Michael R. , Thompson Melissa R. , Demarest Charles W.
Published: January 2010

A CGE method for monitoring the disulfide isomer distribution characteristic of IgG2 MAbs is presented. Disulfide heterogeneity of MAbs has been studied using various chromatographic and electrophoretic methods. Although CGE operates using a different selectivity mechanism from that of sorption chromatographic techniques, similar trends are present in the data, which allow the CGE method to be used as a complementary method for studying disulfide isomer distribution. This article focuses on the optimization of a capillary‐based gel electrophoresis method that can be used to support antibody development including bioprocess optimization, antibody characterization, release, and formulation stability assessment.
Rapid and direct determination of glyphosate, glufosinate, and aminophosphonic acid by online preconcentration CE with contactless conductivity detection
Authors: See Hong Heng , Hauser Peter C. , Ibrahim Wan Aini Wan , Sanagi Mohd Marsin
Published: January 2010

Rapid and direct online preconcentration followed by CE with capacitively coupled contactless conductivity detection (CE‐C4D) is evaluated as a new approach for the determination of glyphosate, glufosinate (GLUF), and aminophosphonic acid (AMPA) in drinking water. Two online preconcentration techniques, namely large volume sample stacking without polarity switching and field‐enhanced sample injection, coupled with CE‐C4D were successfully developed and optimized. Under optimized conditions, LODs in the range of 0.01–0.1 μM (1.7–11.1 μg/L) and sensitivity enhancements of 48‐ to 53‐fold were achieved with the large volume sample stacking‐CE‐C4D method. By performing the field‐enhanced sample injection‐CE‐C4D procedure, excellent LODs down to 0.0005–0.02 μM (0.1–2.2 μg/L) as well as sensitivity enhancements of up to 245‐ to 1002‐fold were obtained. Both techniques showed satisfactory reproducibility with RSDs of peak height of better than 10%. The newly established approaches were successfully applied to the analysis of glyphosate, glufosinate, and aminophosphonic acid in spiked tap drinking water.
Nanoparticle‐based capillary electroseparation of proteins in polymer capillaries under physiological conditions
Authors: Nilsson Christian , Harwigsson Ian , Becker Kristian , Kutter Jörg P. , Birnbaum Staffan , Nilsson Staffan
Published: January 2010

Totally porous lipid‐based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas®, 6.7 cm effective length). In the absence of nanoparticles, i.e. in CE mode, the protein samples adsorbed completely to the capillary walls and could not be recovered. In contrast, nanoparticle‐based capillary electroseparation resolved green fluorescent protein from several of its impurities within 1 min. Furthermore, a mixture of native green fluorescent protein and two of its single‐amino‐acid‐substituted variants was separated within 2.5 min with efficiencies of 400 000 plates/m. The nanoparticles prevent adsorption by introducing a large interacting surface and by obstructing the attachment of the protein to the capillary wall. A one‐step procedure based on self‐assembly of lipids was used to prepare the nanoparticles, which benefit from their biocompatibility and suspension stability at high concentrations. An aqueous tricine buffer at pH 7.5 containing lipid‐based nanoparticles (2% w/w) was used as electrolyte, enabling separation at protein friendly conditions. The developed capillary‐based method facilitates future electrochromatography of proteins on polymer‐based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development.
A novel Escherichia coli‐derived mutation detected with the Big Blue® cII mutant selectable assay
Authors: Ward Tonya L. , Prtenjaca Anita , Hill Kathleen A.
Published: January 2010

Transgenic mouse mutation detection systems allow investigation of the origins and mechanisms of mutation associated with exogenous and endogenous mutagen exposures in individual tissues and cell types. In the past, selection assays for transgenic mutants have been contaminated with nonmurine‐derived mutations and assay validation is critical to ensure murine in vivo origins of mutations. This is critical in studies of spontaneous mutations and extrapolation to endogenous mammalian genes. Herein, we provide one measure of the contribution of Escherichia coli (E. coli)‐derived mutations to the Big Blue® cII transgene mutant selection assay. We report the first direct evidence of an E. coli‐derived cII mutation identified among mutations recovered in the cII selective assay. An E. coli transposable 5 (Tn5) element IS50R inverted repeat (1,534 bp) was identified at base pair 414 in the cII transgene and the insertion generated a 9 bp target site duplication typical of this type of transposition. The bacterial transposition occurred only once in the assay of 25 × 106 plaque forming units and sequencing of 1,177 cII mutants. The observed frequency of this type of mutation is 4 × 10−8 in retrieved λ phage and 8.5 × 10−4 in harvested cII mutants and thus a very rare occurrence in typical analyses of spontaneous in vivo mutations. Given that the frequency of transposition is equal to, or an order of magnitude higher, than the frequency of point mutations in E. coli, this article provides excellent validation for the murine origins of mutations detected using the cII mutant selection assay. Environ. Mol. Mutagen. 2010. © 2010 Wiley‐Liss, Inc.
The generation of wear‐resistant antimicrobial stainless steel surfaces by active screen plasma alloying with N and nanocrystalline Ag
Authors: Dong Yangchun , Li Xiaoying , Sammons Rachel , Dong Hanshan
Published: January 2010

Hospital‐acquired infections (HAIs), a large proportion of which are derived from contact transmission, represent a massive global challenge. In this study a novel active screen plasma (ASP) alloying technology has been developed to generate highly durable antimicrobial surfaces by combining a wear‐resistant S‐phase with nanocrystalline silver for medical grade stainless steel. The phase constituent, microstructure, composition and surface roughness of the alloyed surfaces were fully characterized, and the surface hardness, wear resistance and antimicrobial efficiency of the treated surfaces were evaluated. Experimental results showed that the surface hardness and sliding wear resistance of medical grade 316LVM stainless steel can be effectively improved by the ASP alloying treatment; furthermore, the Ag alloyed S‐phase can achieve 93% reduction in Escherichia coli (E. coli) after 6 h contact time. Therefore, the novel ASP alloying treatment can not only improve wear resistance but also confer antibacterial activity to stainless steel surfaces. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res PartB: Appl Biomater, 2010
In vitro antibacterial efficacy of tetracycline hydrochloride adsorbed onto Bio‐Oss® bone graft
Authors: Dashti A. , Ready D. , Salih V. , Knowles J. C. , Barralet J. E. , Wilson M. , Donos N. , Nazhat S. N.
Published: January 2010

Local delivery of antibiotics may provide the advantage of reducing the potential side effects associated with their systemic administration. This study assessed, in vitro, the antimicrobial efficacy of tetracycline hydrochloride (TCH) adsorbed onto Bio‐Oss® bone grafts against a range of pathogenic bacteria. Various levels of TCH were adsorbed onto Bio‐Oss® granules by immersing in TCH aqueous solutions of different initial concentrations for 48 h at room temperature. TCH release was assessed in phosphate buffered saline at 37°C, and its antimicrobial efficacy, up to 96 h, was tested against two Gram‐negative bacteria associated with periodontal diseases: Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, and Porphyromonas gingivalis, and one Gram‐positive bacterium associated with soft‐tissue and bone infections: Staphylococcus aureus. The range of TCH concentrations studied was also assessed for cytotoxicity against osteoblast‐like human osteosarcoma cell lines. The amount of TCH adsorbed and released from Bio‐Oss® was concentration dependent. All TCH adsorbed Bio‐Oss® resulted in a reduction of A. actinomycetemcomitans, P. gingivalis, and S. aureus and higher concentrations were generally more effective in reducing or eliminating bacterial growth. The proliferation of HOS cells was not substantially reduced except for the maximum concentration of TCH. In addition to its osteoconductive role, TCH adsorbed Bio‐Oss® could also be functional in negating systemically antibiotic prophylactic treatment in the prevention of implant or biomaterial related infections. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Mechanical implications of estrogen supplementation in early postmenopausal women
Authors: Wehrli Felix W , Rajapakse Chamith S , Magland Jeremy F , Snyder Peter J
Published: January 2010

Whereas the structural implications of drug intervention are well established, there are few data on the possible mechanical consequences of treatment. In this work we examined the changes in elastic and shear moduli (EM and SM) in a region of trabecular bone in the distal radius and distal tibia of early postmenopausal women on the basis of MRI-based micro-finite-element (µFE) analysis. Whole-section axial stiffness (AS) encompassing both trabecular and cortical compartments was evaluated as well. The study was conducted on previously acquired high-resolution images at the two anatomic sites. Images were processed to yield a 3D voxel array of bone-volume fraction (BVF), which was converted to a µFE model of hexahedral elements in which tissue modulus was set proportional to voxel BVF. The study comprised 65 early postmenopausal women (age range 45 to 55 years), of whom 32 had chosen estrogen supplementation (estradiol group); the remainder had not (control group). Subjects had been scanned at baseline and 12 and 24 months thereafter. At the distal tibia, EM and SM were reduced by 2.9% to 5.5% in the control group (p < .05 to <.005), but there was no change in the estradiol subjects. AS decreased 3.9% (4.0%) in controls (p < .005) and increased by 5.8% (6.2%) in estradiol group subjects (p < .05) at 12 (24) months. At the distal radius, EM and SM changes from baseline were not significant, but at both time points AS was increased in estradiol group subjects and decreased in controls (p < .005 to <.05), albeit by a smaller margin than at the tibia. EM and SM were strongly correlated with BV/TV (r2 = 0.44 to 0.92) as well as with topologic parameters expressing the ratio of plates to rods (r2 = 0.45 to 0.82), jointly explaining up to 96% of the variation in the mechanical parameters. Finally, baseline AS was strongly correlated between the two anatomic sites (r2 = 0.58), suggesting that intersubject variations in the bone's mechanical competence follows similar mechanisms. In conclusion, the results demonstrate that micro-MRI-based µFE models are suited for the study of the mechanical implications of antiresorptive treatment. The data further highlight the anabolic effect of short-term estrogen supplementation. © 2010 American Society for Bone and Mineral Research
Time since prior fracture is a risk modifier for 10-year osteoporotic fractures
Authors: Giangregorio Lora M , Leslie William D
Published: January 2010

The objective of this study was to assess the importance of time since prior fracture as a risk factor for future osteoporotic fractures and how it affects 10-year fracture rates. We identified 39,991 women 45 years of age or older undergoing baseline bone mineral density (BMD) testing (1990–2007) from a regional database that contains dual-energy X-ray absorptiometry (DXA) results for Manitoba, Canada. Health service records were used to identify nontrauma ICD-9-CM fracture codes preceding DXA, grouped as “major” fractures (n = 5178; hip, spine, forearm, and humerus) or “minor” fractures (n = 3479; ribs, sternum, pelvis, trunk, clavicle, scapula, patella, tibia/fibula, and ankle). Time since prior fracture was coded in years as less than 1, 1 to 5, 5 to 10, and more than 10. Incident fractures (ie, hip, spine, forearm, and humerus) after BMD testing were identified (mean follow-up 4.2 years, maximum 10 years) and studied in Cox proportional-hazards models adjusted for age, BMD T-score, and other covariates. After BMD testing, n = 1749 (4.4%) women experienced an incident fracture. Prior major fracture was a strong risk factor for incident fracture, greatest risk in the first year [hazard ratio (HR) 1.90, 95% confidence interval (CI) 1.60–2.25], declining by more than 10 years (HR 1.62, 95% CI 1.25–2.10). Prior minor fracture was a weaker risk factor, greatest in the first year (HR 1.45, 95% CI 1.13–1.87) and no longer significant by 1 to 5 years. Major and minor fractures both showed a time-dependent decline in importance as risk factors. In conclusion, time since prior fracture modifies future fracture risk, but prior fractures of the hip, spine, forearm, and humerus remain strong risk factors even 10 years later. Fracture risk assessment should emphasize the importance of prior fractures at these sites.
Pathway-based genome-wide association analysis identified the importance of regulation-of-autophagy pathway for ultradistal radius BMD
Authors: Zhang Lishu , Guo Yan-Fang , Liu Yao-Zhong , Liu Yong-Jun , Xiong Dong-Hai , Liu Xiao-Gang , Wang Liang , Yang Tie-Lin , Lei Shu-Feng , Guo Yan , Yan Han , Pei Yu-Fang , Zhang Feng , Papasian Christopher J , Recker Robert R , Deng Hong-Wen
Published: January 2010

Wrist fracture is not only one of the most common osteoporotic fractures but also a predictor of future fractures at other sites. Wrist bone mineral density (BMD) is an important determinant of wrist fracture risk, with high heritability. Specific genes underlying wrist BMD variation are largely unknown. Most published genome-wide association studies (GWASs) have focused only on a few top-ranking single-nucleotide polymorphisms (SNPs)/genes and considered each of the identified SNPs/genes independently. To identify biologic pathways important to wrist BMD variation, we used a novel pathway-based analysis approach in our GWAS of wrist ultradistal radius (UD) BMD, examining approximately 500,000 SNPs genome-wide from 984 unrelated whites. A total of 963 biologic pathways/gene sets were analyzed. We identified the regulation-of-autophagy (ROA) pathway that achieved the most significant result (p = .005, qfdr = 0.043, pfwer = 0.016) for association with UD BMD. The ROA pathway also showed significant association with arm BMD in the Framingham Heart Study sample containing 2187 subjects, which further confirmed our findings in the discovery cohort. Earlier studies indicated that during endochondral ossification, autophagy occurs prior to apoptosis of hypertrophic chondrocytes, and it also has been shown that some genes in the ROA pathway (e.g., INFG) may play important roles in osteoblastogenesis or osteoclastogenesis. Our study supports the potential role of the ROA pathway in human wrist BMD variation and osteoporosis. Further functional evaluation of this pathway to determine the mechanism by which it regulates wrist BMD should be pursued to provide new insights into the pathogenesis of wrist osteoporosis. © 2010 American Society for Bone and Mineral Research
Cell-based immunotherapy with mesenchymal stem cells cures bisphosphonate-related osteonecrosis of the jaw–like disease in mice
Authors: Kikuiri Takashi , Kim Insoo , Yamaza Takyoshi , Akiyama Kentaro , Zhang Qunzhou , Li Yunsheng , Chen Chider , Chen WanJun , Wang Songlin , Le Anh D , Shi Songtao
Published: January 2010

Patients on high-dose bisphosphonate and immunosuppressive therapy have an increased risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ); despite the disease severity, its pathophysiology remains unknown, and appropriate therapy is not established. Here we have developed a mouse model of BRONJ-like disease that recapitulates major clinical and radiographic manifestations of the human disease, including characteristic features of an open alveolar socket, exposed necrotic bone or sequestra, increased inflammatory infiltrates, osseous sclerosis, and radiopaque alveolar bone. We show that administration of zoledronate, a potent aminobisphosphonate, and dexamethasone, an immunosuppressant drug, causes BRONJ-like disease in mice in part by suppressing the adaptive regulatory T cells, Tregs, and activating the inflammatory T-helper-producing interleukin 17 cells, Th17. Most interestingly, we demonstrate that systemic infusion with mesenchymal stem cells (MSCs) prevents and cures BRONJ-like disease possibly via induction of peripheral tolerance, shown as an inhibition of Th17 and increase in Treg cells. The suppressed Tregs/Th17 ratio in zoledronate- and dexamethasone-treated mice is restored in mice undergoing salvage therapy with Tregs. These findings provide evidence of an immunity-based mechanism of BRONJ-like disease and support the rationale for in vivo immunomodulatory therapy using Tregs or MSCs to treat BRONJ. © 2010 American Society for Bone and Mineral Research
Genetically determined phenotype covariation networks control bone strength
Authors: Jepsen Karl J , Courtland Hayden-William , Nadeau Joseph H
Published: January 2010

To identify genes affecting bone strength, we studied how genetic variants regulate components of a phenotypic covariation network that was previously shown to accurately characterize the compensatory trait interactions involved in functional adaptation during growth. Quantitative trait loci (QTLs) regulating femoral robustness, morphologic compensation, and mineralization (tissue quality) were mapped at three ages during growth using AXB/BXA Recombinant Inbred (RI) mouse strains and adult B6-iA Chromosome Substitution Strains (CSS). QTLs for robustness were identified on chromosomes 8, 12, 18, and 19 and confirmed at all three ages, indicating that genetic variants established robustness postnatally without further modification. A QTL for morphologic compensation, which was measured as the relationship between cortical area and body weight, was identified on chromosome 8. This QTL limited the amount of bone formed during growth and thus acted as a setpoint for diaphyseal bone mass. Additional QTLs were identified from the CSS analysis. QTLs for robustness and morphologic compensation regulated bone structure independently (ie, in a nonpleiotropic manner), indicating that each trait may be targeted separately to individualize treatments aiming to improve strength. Multiple regression analyses showed that variation in morphologic compensation and tissue quality, not bone size, determined femoral strength relative to body weight. Thus an individual inheriting slender bones will not necessarily inherit weak bones unless the individual also inherits a gene that impairs compensation. This systems genetic analysis showed that genetically determined phenotype covariation networks control bone strength, suggesting that incorporating functional adaptation into genetic analyses will advance our understanding of the genetic basis of bone strength. © 2010 American Society for Bone and Mineral Research
Microalgae as feedstock for biodiesel production: Carbon dioxide sequestration, lipid production and biofuel quality
Authors: Francisco Érika C , Neves Débora B , Jacob‐Lopes Eduardo , Franco Telma T
Published: January 2010

BACKGROUND: The novelty of this work is the estimation of the fuel properties of biodiesel, a comparison study with conventional sources of biodiesel commonly used as feedstock, and an investigation for meeting the requirements of the standard specifications for this fuel produced by six strains of microalgae (three cyanobacteria, two green algae and one diatom), cultivated photosynthetically in a bubble column photobioreactor. Lipid productivity and biofuel quality were the criteria for species selection.

RESULTS: Chlorella vulgaris was found to be the best strain for use as a feedstock for biodiesel production and for this specie, a carbon dioxide sequestration rate of 17.8 mg L−1 min−1, a biomass productivity of 20.1 mg L−1 h−1, a lipid content of 27.0% and a lipid productivity of 5.3 mg L−1 h−1 were obtained. Qualitative analysis of the fatty acid methyl esters demonstrates the predominance of saturated (43.5%) and monounsaturated (41.9%) fatty acids. The quality properties of the biodiesel were an ester content of 99.8%, a cetane number of 56.7; an iodine value of 65.0 g I2 100 g−1; a degree of unsaturation of 74.1% and a cold filter plugging point of 4.5 °C.

CONCLUSION: The results indicate that among the fuel properties tested, the microalgal biodiesel complies with the US Standard (ASTM 6751), European Standard (EN 14214), Brazilian National Petroleum Agency (ANP 255) and Australian Standard for biodiesel. Copyright © 2010 Society of Chemical Industry