bluuebunny/crossref_metadata_2025 huggingface dataset:
An Iron(II) Spin‐Transition Compound with Thiol Anchoring Groups (Eur. J. Inorg. Chem. 17/2008)
Authors: Chandrasekar Rajadurai , Schramm Frank , Fuhr Olaf , Ruben Mario
Published: May 2008

The cover picture shows
the solid‐state structure and magnetic susceptibility data of an iron(II) spin‐transition complex, which was designed, synthesized and characterized in the group of Mario Ruben at the Institute of Nanotechnology in Karlsruhe. The complex, which undergoes a near‐room‐temperature transition from a closed‐shell spin singlet to an open‐shell high‐spin state, holds promise for the controlled manipulation and readout of the magnetic states of single molecules. In order to integrate and to implement such switchable spin‐transition units into electronic devices, the molecule bears protected thiol linkers, which allows its attachment to gold electrodes (bottom). Details are discussed in the Short Communication on p. 2649 ff.
The Australian Research Quality Framework: A live experiment in capturing the social, economic, environmental, and cultural returns of publicly funded research
Authors: Donovan Claire
Published: May 2008

The author regards development of Australia's ill‐fated Research Quality Framework (RQF) as a “live experiment” in determining the most appropriate approach to evaluating the extra‐academic returns, or “impact,” of a nation's publicly funded research. The RQF was at the forefront of an international movement toward richer qualitative, contextual approaches that aimed to gauge the wider economic, social, environmental, and cultural benefits of research. Its construction and implementation sent mixed messages and created confusion about what impact is, and how it is best measured, to the extent that this bold live experiment did not come to fruition. © Wiley Periodicals, Inc.
The logic of research evaluation
Authors: Scriven Michael , Coryn Chris L. S.
Published: May 2008

The authors offer suggestions about logical distinctions often overlooked in the evaluation of research, beginning with a strong plea not to treat technology as applied science, and especially not to treat research in technology as important only if it makes a contribution to scientific knowledge. They argue that the frameworks illustrated in this issue for the evaluation of technology centers and their research are superior to those used for evaluating science centers. Ways to improve the evaluation of research are suggested. © Wiley Periodicals, Inc.
Direction‐of‐change forecasting using a volatility‐based recurrent neural network
Authors: Bekiros S. D. , Georgoutsos D. A.
Published: May 2008

This paper investigates the profitability of a trading strategy, based on recurrent neural networks, that attempts to predict the direction‐of‐change of the market in the case of the NASDAQ composite index. The sample extends over the period 8 February 1971 to 7 April 1998, while the sub‐period 8 April 1998 to 5 February 2002 has been reserved for out‐of‐sample testing purposes. We demonstrate that the incorporation in the trading rule of estimates of the conditional volatility changes strongly enhances its profitability, after the inclusion of transaction costs, during bear market periods. This improvement is being measured with respect to a nested model that does not include the volatility variable as well as to a buy‐and‐hold strategy. We suggest that our findings can be justified by invoking either the ‘volatility feedback’ theory or the existence of portfolio insurance schemes in the equity markets. Our results are also consistent with the view that volatility dependence produces sign dependence. Copyright © 2008 John Wiley & Sons, Ltd.
Rapid virological response and treatment duration for chronic hepatitis C genotype 1 patients: A randomized trial
Authors: Yu Ming-Lung , Dai Chia-Yen , Huang Jee-Fu , Chiu Chang-Fu , Yang Yi-Hsin C. , Hou Nai-Jen , Lee Li-Po , Hsieh Ming-Yen , Lin Zu-Yau , Chen Shinn-Cherng , Hsieh Ming-Yuh , Wang Liang-Yen , Chang Wen-Yu , Chuang Wan-Long
Published: May 2008

Recommended treatment for hepatitis C virus genotype 1 (HCV-1) patients is peginterferon plus ribavirin for 48 weeks. We assessed whether treatment duration of 24 weeks is as effective as standard treatment in HCV-1 patients with a rapid virological response (RVR; seronegative for hepatitis C virus [HCV] RNA at 4 weeks). Two hundred HCV-1 patients were randomized (1:1) to either 24 or 48 weeks of peginterferon-alpha-2a (180 μg/week) and ribavirin (1000–1200 mg/day) with a 24-week follow-up. The primary endpoint was a sustained virological response (SVR; seronegative for HCV RNA at 24-week follow-up). Overall, the 48-week arm had a significantly higher SVR rate (79%) than the 24-week arm (59%,

P

= 0.002). For 87 (43.5%) patients with an RVR, the 24-week arm had a lower SVR rate [88.9%; 95% confidence interval (CI): 80%–98%] than the 48-week arm (100%,

P

= 0.056). For 52 patients with low baseline viremia (<400,000 IU/mL) and an RVR, the 24-week arm had rates (CI) of relapse and SVR of 3.6% (−3%–11%) and 96.4% (89%–103%), respectively, which were comparable to those of the 48-week arm (0% and 100%) with difference (CI) of 3.6% (−7.2%–6.6%) and −3.6% (−14.3% to −0.6%), respectively. Multivariate analysis in all patients showed that RVR was the strongest independent factor associated with an SVR, followed by treatment duration, mean weight–based exposure of ribavirin, and baseline viral load.

Conclusion:

HCV-1 patients derive a significantly better SVR from 48 weeks versus 24 weeks of peginterferon/ribavirin even if they attain an RVR. Both 24 and 48 weeks of therapy can achieve high SVR rates (>96%) in HCV-1 patients with low viral loads and an RVR.
Evaluating sulfur dynamics during storm events for three watersheds in the northeastern USA: a combined hydrological, chemical and isotopic approach
Authors: Mitchell Myron J. , Bailey Scott W. , Shanley James B. , Mayer Bernhard
Published: May 2008

Concerns related to climate change have resulted in an increasing interest in the importance of hydrological events such as droughts in affecting biogeochemical responses of watersheds. The effects of an unusually dry summer in 2002 had a marked impact on the biogeochemistry of three watersheds in the north‐eastern USA. Chemical, isotopic and hydrological responses with particular emphasis on S dynamics were evaluated for Archer Creek (New York), Sleepers River (Vermont) and Cone Pond (New Hampshire) watersheds. From 1 August to 14 September 2002, all three watersheds had very low precipitation (48 to 69 mm) resulting in either very low or no discharge (mean 0·015, 0·15 and 0·000 mm day−1 for Archer Creek, Sleepers River and Cone Pond, respectively). From 15 September to 31 October 2002, there was a substantial increase in precipitation totals (212, 246 and 198 mm, respectively) with increased discharge. Archer Creek was characterized by a large range of SO42− concentrations (152 to 389 µeq L−1, mean = 273 µeq L−1) and also exhibited the greatest range in δ34S values of SO42− (−1·4 to 8·8 ‰ ). Sleepers River's SO42− concentrations ranged from 136 to 243 µeq L−1 (mean = 167 µeq L−1) and δ34S values of SO42− ranged from 4·0 to 9·0 ‰ . Cone Pond's SO42− concentrations (126–187 µeq L−1, mean = 154 µeq L−1) and δ34S values (2·4 to 4·3 ‰ ) had the smallest ranges of the three watersheds. The range and mean of δ18O‐SO42− values for Archer Creek and Cone Pond were similar (3·0 to 8·9 ‰ , mean = 4·5 ‰ ; 3·9 to 6·3 ‰ , mean = 4·9 ‰ ; respectively) while δ18O‐SO42− values for Sleepers River covered a larger range with a lower mean (1·2 to 10·0 ‰ , mean = 2·5). The difference in Sleepers River chemical and isotopic responses was attributed to weathering reactions contributing SO42−. For Archer Creek wetland areas containing previously reduced S compounds that were reoxidized to SO42− probably provided a substantial source of S. Cone Pond had limited internal S sources and less chemical or isotopic response to storms. Differences among the three watersheds in S biogeochemical responses during these storm events were attributed to differences in S mineral weathering contributions, hydrological pathways and landscape features. Further evaluations of differences and similarities in biogeochemical and hydrological responses among watersheds are needed to predict the impacts of climate change. Copyright © 2008 John Wiley & Sons, Ltd.
Lateral flow thresholds for aspen forested hillslopes on the Western Boreal Plain, Alberta, Canada
Authors: Redding T. E. , Devito K. J.
Published: May 2008

To predict the long‐term sustainability of water resources on the Boreal Plain region of northern Alberta, it is critical to understand when hillslopes generate runoff and connect with surface waters. The sub‐humid climate (P ≤ ET) and deep glacial sediments of this region result in large available soil storage capacity relative to moisture surpluses or deficits, leading to threshold‐dependent rainfall‐runoff relationships. Rainfall simulation experiments were conducted using large magnitude and high intensity applications to examine the thresholds in precipitation and soil moisture that are necessary to generate lateral flow from hillslope runoff plots representative of Luvisolic soils and an aspen canopy. Two adjacent plots (areas of 2·95 and 3·4 m2) of contrasting antecedent moisture conditions were examined; one had tree root uptake excluded for two months to increase soil moisture content, while the second plot allowed tree uptake over the growing season resulting in drier soils. Vertical flow as drainage and soil moisture storage dominated the water balances of both plots. Greater lateral flow occurred from the plot with higher antecedent moisture content. Results indicate that a minimum of 15–20 mm of rainfall is required to generate lateral flow, and only after the soils have been wetted to a depth of 0·75 m (C‐horizon). The depth and intensity of rainfall events that generated runoff > 1 mm have return periods of 25 years or greater and, when combined with the need for wet antecendent conditions, indicate that lateral flow generation on these hillslopes will occur infrequently. Copyright © 2008 John Wiley & Sons, Ltd.
Upregulation of miR‐23a∼27a∼24 decreases transforming growth factor‐beta‐induced tumor‐suppressive activities in human hepatocellular carcinoma cells
Authors: Huang Shenglin , He Xianghuo , Ding Jie , Liang Linhui , Zhao Yingjun , Zhang Zhenfeng , Yao Xiao , Pan Zhimei , Zhang Pingping , Li Jinjun , Wan Dafang , Gu Jianren
Published: May 2008

Transforming growth factor‐beta (TGF‐beta) plays a dual and complex role in human cancer. In this report, we observe a specific set of MicroRNAs (miRNAs) changed in response to TGF‐beta in human hepatocellular carcinoma (HCC) cells by miRNA microarray screening. A cluster of miRNA, miR‐23a∼27a∼24, is induced in an early stage by TGF‐beta in Huh‐7 cells. Knockdown of Smad4, Smad2 or Smad3 expression by RNA interference can attenuate the response of miR‐23a∼27a∼24 to TGF‐beta addition, indicating that this induction is dependent on Smad pathway. We also explore that miR‐23a∼27a∼24 can function as an antiapoptotic and proliferation‐promoting factor in liver cancer cells. In addition, expression of this miRNA cluster is found to be remarkably upregulated in HCC tissues versus normal liver tissues. These findings suggest a novel, alternative mechanism through which TGF‐beta could induce specific miRNA expression to escape from tumor‐suppressive response in HCC cells. © 2008 Wiley‐Liss, Inc.
Kaempferol: A new immunosuppressant of calcineurin
Authors: Wang Hu , Zhou Chun‐Lei , Lei Hong , Zhang Song‐Dong , Zheng Jianquan , Wei Qun
Published: May 2008

Calcineurin (CN), the Ca2+/calmodulin (CaM)‐dependant protein phosphatase, is the target for immunosuppressive drugs cyclosporine A (CsA) and FK506. These immunosuppressants can inhibit CN activity after binding with respective immunophilins. Based on the model of screening by using p‐nitrophenyl phosphate as a substrate for preliminary screening and 32P‐labeled 19‐residue phosphopeptide as a specific substrate for final determination, we found Kaempferol, a natural flavonol, could inhibit CN activity in purified enzyme and Jurkat T‐cells. Unlike CsA and FK506, CN inhibition by kaempferol is independent of matchmaker protein and the inhibitory manner is noncompetitive. Through investigation of inhibitions for CNA and a series of its truncated mutants, we suggested that Kaempferol could directly act on the catalytic domain. Data also indicated that the CN inhibition by kaempferol could be enhanced when the enzyme was activated in the presence of CaM and CNB. CNB is necessary for mediating inhibition of enzyme by kaempferol. The result of RT‐PCR also indicated that kaempferol had an inhibitory activity against IL‐2 gene expression in activated Jurkat cells. All data suggested that kaempferol could be a new immunosuppressant of CN. © 2008 IUBMB IUBMB Life, 60(8): 549–554, 2008
Proteasome activation as a novel antiaging strategy
Authors: Chondrogianni Niki , Gonos Efstathios S.
Published: May 2008

Homeostasis is a key feature of cellular lifespan. Maintenance of cellular homeostasis influences the rate of aging and is determined by several factors, including efficient proteolysis of damaged proteins. Protein degradation is predominately catalyzed by the proteasome. Specifically, the proteasome is responsible for cell clearance of abnormal, denatured or in general damaged proteins as well as for the regulated degradation of short‐lived proteins. As proteasome has an impaired function during aging, emphasis has been given recently in identifying ways of its activation. A number of studies have shown that the proteasome can be activated by genetic manipulations as well as by factors that affect its conformation and stability. Importantly the developed proteasome activated cell lines exhibit an extended lifespan. This review article discusses in details the various factors that are involved in proteasome biosynthesis and assembly and how they contribute to its activation. Finally as few natural compounds have been identified having proteasome activation properties, we discuss the advantages of this novel antiaging strategy. © 2008 IUBMB IUBMB Life, 60(10): 651–655, 2008
A DNA transporter based on mesoporous silica nanospheres mediated with polycation poly(allylamine hydrochloride) coating on mesopore surface
Authors: Qin Fei , Zhou Yuchuan , Shi Jianlin , Zhang Yonglian
Published: May 2008

Mesoporous silica nanospheres (MPNSs) were synthesized by the sol–gel method and were investigated by X‐ray diffraction, nitrogen sorption, and transmission electron microscopy. The analyses showed that the MPNSs were highly dispersed, with a diameter range of 50–250 nm. Further, the polycation poly(allylamine hydrochloride) was coated on silica MPNSs to form a positively charged surface and to facilitate the loading of DNA molecules. The composite was successfully used as a intercellular carrier of DNA molecules, and this was confirmed by agarose gel electrophoresis and confocal laser scanning microscopy. Evidently, this composite has potential to be used as a carrier for a DNA delivery system. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Physico/chemical characterization and in vivo evaluation of nanothickness bioceramic depositions on alumina‐blasted/acid‐etched Ti‐6Al‐4V implant surfaces
Authors: Coelho Paulo G. , Lemons Jack E.
Published: May 2008

The objective of this study was to physico/chemically characterize and evaluate the in vivo performance of two nanothickness ion beam assisted depositions (IBAD) of bioceramic coatings on implants in a beagle model. Alumina‐blasted/acid‐etched (AB/AE) Ti‐6Al‐4V implants were subjected to two different IBAD depositions (IBAD I and IBAD II), which were physico/chemically characterized by SEM, EDS, XPS, XPS + ion‐beam milling (depth profiling), XRD, AFM, and ToF‐SIMS. A beagle dog tibia model was utilized for histomorphometric and biomechanical (torque) comparison between AB/AE, IBAD I, IBAD II, and plasma‐sprayed hydroxyapatite (PSHA) coated implants that remained in vivo for 3 and 5 weeks. The coatings were characterized as amorphous Ca‐P with high Ca/P stoichiometries with thicknesses of an order of magnitude difference (IBAD I = 30–50 nm and IBAD II = 300–500 nm). The histomorphometric and biomechanical testing results showed that the 300–500 nm thickness deposition (IBAD II) and PSHA positively modulated bone healing at early implantation times. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Impaction allografting—The effect of impaction force and alternative compaction methods on the mechanical characteristics of the graft
Authors: Albert Carolyne , Masri Bassam , Duncan Clive , Oxland Thomas , Fernlund Göran
Published: May 2008

Revision total hip replacement with impaction allografting has an attractive potential for restoring bone stock, however, fractures and implant migration remain problematic. Postoperative graft deformation is believed to contribute to migration. Under compressive loading, the fluid in the graft takes up the load initially through fluid pressure that dissipates over time. Given the short duration of an impaction, we proposed two novel graft compaction techniques that allow more time for fluid flow: holding a compression force constant for 90 s (creep technique), and cycles of compressing the graft to a given force and then holding the displacement constant (cyclic relaxation technique). This study examined the effect of the impaction force on the density and mechanical characteristics of the graft, and explored the potential benefit of the proposed alternative compaction techniques. Increasing the impaction force from “low” to “high” increased graft density by 41%, and this translated to stiffness and shear strength increases of 93 and 164%, respectively. The creep technique improved the stiffness and shear strength by 14 and 16%, respectively, when compared with impaction, while the cyclic relaxation technique did not improve the mechanical properties. Although the creep technique could potentially provide a lower risk of intraoperative fracture over the use of larger impaction forces, any clinical benefit of the creep technique warrants further investigation. Our results point to the importance of maximizing impaction forces in impaction allografting surgery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Fabrication, characterization, and biocompatibility of single‐walled carbon nanotube‐reinforced alginate composite scaffolds manufactured using freeform fabrication technique
Authors: Yildirim Eda D. , Yin Xi , Nair Kalyani , Sun Wei
Published: May 2008

Composite polymeric scaffolds from alginate and single‐walled carbon nanotube (SWCNT) were produced using a freeform fabrication technique. The scaffolds were characterized for their structural, mechanical, and biological properties by scanning electron microscopy, Raman spectroscopy, tensile testing, and cell–scaffold interaction study. Three‐dimensional hybrid alginate/SWCNT tissue scaffolds were fabricated in a multinozzle biopolymer deposition system, which makes possible to disperse and align SWCNTs in the alginate matrix. The structure of the resultant scaffolds was significantly altered due to SWCNT reinforcement, which was confirmed by Raman spectroscopy. Microtensile testing presented a reinforcement effect of SWCNT to the mechanical strength of the alginate struts. Ogden constitutive modeling was utilized to predict the stress–strain relationship of the alginate scaffold, which compared well with the experimental data. Cellular study by rat heart endothelial cell showed that the SWCNT incorporated in the alginate structure improved cell adhesion and proliferation. Our study suggests that hybrid alginate/SWCNT scaffolds are a promising biomaterial for tissue engineering applications. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Photocatalytic and antibacterial properties of medical‐grade PVC material coated with TiO2 film
Authors: Lin Huaxiang , Xu Ziting , Wang Xuxu , Long Jinlin , Su Wenyue , Fu Xianzhi , Lin Qun
Published: May 2008

The TiO2 film was coated on poly vinyl chloride (PVC) surface by dip‐coating process from TiO2–PVC–THF suspension. The morphology and crystal structure of the as‐synthesized samples were characterized by SEM and XRD. The photocatalytic properties were measured by the photodegradation reaction of RhB and the anti‐adhesion and anti‐bacteria for Escherichia coli. The results show that the resultant TiO2 film is well‐conglutinated on PVC surface and has the same crystal structure as the original TiO2 powder. The TiO2/PVC shows excellent photocatalytic activity for the degradation of aqueous RhB and the activity increases with increasing reaction time and tends toward stable after accumulative illumination for 11.5 h. The TiO2 film shows good bacterial anti‐adhesion activity following photo‐activation and sterilization property under UV irradiation. The E. coli can be killed completely after UV irradiation for 1.5 h. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 87B: 425–431, 2008
Remaining unreacted methacrylate groups in resin‐based composite with respect to sample preparation and storing conditions using micro‐Raman spectroscopy
Authors: Miletic Vesna J. , Santini Ario
Published: May 2008

The aim of this study was to measure degree of conversion (DC) of resin‐based composites (RBCs) using micro‐Raman spectroscopy followed by different sample preparation procedures and storing conditions. Ninety samples of Tetric EvoCeram (Ivoclar Vivadent, Schaan, Liechtenstein) were prepared in standardized molds and cured with a high powered LED light‐curing unit, bluephase® (Ivoclar Vivadent, Schaan, Liechtenstein) for 20 s. Samples were allocated to eight groups. DC of groups 1 and 2 was recorded without or after polishing. DC in groups 3 and 4 was recorded from vertically sectioned samples versus “split” samples. DC in groups 5–8 was recorded after storing samples at room temperature and humidity, in 90 ± 2% humidity at 37 ± 1°C, distilled water at 37 ± 1°C or buffered incubation medium (BIM) at 37 ± 1°C for 24 h. Mean values of DC in polished and unpolished samples were 63.6% (±3.2%) and 54.7% (±5.2%), respectively (p < 0.0001). There was no significant difference in DC after sample‐sectioning (p > 0.05). Significantly higher DC values were obtained after storing samples in BIM (76.8% ± 2.1%) than in distilled water (59.7% ± 5.7%), extreme humidity (60.3% ± 3.9%) or in room conditions (63.6% ± 3.2%) (p < 0.001). DC of an RBC measured by micro‐Raman spectroscopy may be affected by differences in sample preparation and storing conditions, making it difficult to extrapolate data from in vitro studies into clinically relevant information. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Bisphosphonate‐laden acrylic bone cement: Mechanical properties, elution performance, and in vivo activity
Authors: Yu Nicole Y. C. , Ruys Andrew J. , Zenios Michalis , Godfrey Craig , McDonald Michelle , Kiely Patrick , Mikulec Kathy , Little David G. , Schindeler Aaron
Published: May 2008

Cemented total hip replacements generally fail after 10–20 years, often due to implant loosening from bone resorption. Bisphosphonates such as zoledronic acid (ZA) and pamidronate (PAM) are potent inhibitors of bone resorption. The local delivery of bisphosphonates via acrylic bone cement could decrease osteolysis and prolong implant lifespan. Conflicting studies suggest that bisphosphonate loading may or may not reduce the mechanical properties of acrylic bone cement. We assayed acrylic bone cement laden with ZA or PAM at different concentrations and diluent volumes. Four‐point bend testing and compressive testing indicated that high volumes of diluent (with or without bisphosphonate) significantly reduced bending modulus and compressive strength. Radiography and electron microscopy indicated that high diluent volumes generated abnormal acrylic bone cement structure. After 6 weeks of incubation in saline, only 0.9% w/w of the total bisphosphonate incorporated in acrylic bone cement eluted in vitro, indicating a slow elution rate. In vivo testing was performed using a rat model. Cement cylinders were inserted into incisions in rat distal femora and ZA delivered locally (via elution from acrylic bone cement) or systemically (via injection). At 4 weeks postoperatively, dual energy X‐ray absorptiometry demonstrated no significant increase in local bone mineral density (BMD) adjacent to ZA‐laden implants. In contrast, systemic ZA delivery (0.1 mg/kg) led to a large (48.6%) and significant increase in BMD. Thus, systemic delivery appears more effective than local delivery. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
The distribution of crystalline material in obstructed stents—In need for intra‐luminal surface modification?
Authors: Laube Norbert , Kleinen Lisa , Avrutin Vadym , Böde Ulla , Meißner Andreas , Fisang Christian
Published: May 2008

Purpose: Usually, hampered urine flow and failing of Seldinger technique leads to the explanation “obstructed ureteral stent” with no further clarification where exactly the obstructions are located. If stent obstruction is caused by intra‐luminal biofilm and/or crystal deposits, the need of biofilm reducing coatings on the stent's inside has to be discussed. Materials and Methods: We investigated 59 stents from patients in whom acute hydronephrosis and/or acute pyelonephritis required stent replacement and/or usage of Seldinger technique failed. The stents were investigated by X‐ray and, after longitudinal cutting, by light‐microscopy for occurrence of obstructing material. Results: The inside of 25% of the samples was lined with a thick film composed of blood clots and tiny non‐aggregated crystals. Only in these samples X‐ray investigation showed a positive result for massive inner encrustations, which in fact may be responsible for stent occlusion. 48% of the stents contained few small domains composed of blood clots and crystals. 27% of the stent samples showed no alteration. Conclusions: 75% of the “obstructed” stents showed no significant inner deposits. Obstruction of urine transport and failure of Seldinger technique occurred due to other reasons. Thus, coating of the stent's inner surface may be overrated. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Change in cell shape is required for matrix metalloproteinase‐induced epithelial‐mesenchymal transition of mammary epithelial cells
Authors: Nelson Celeste M. , Khauv Davitte , Bissell Mina J. , Radisky Derek C.
Published: May 2008

Cell morphology dictates response to a wide variety of stimuli, controlling cell metabolism, differentiation, proliferation, and death. Epithelial‐mesenchymal transition (EMT) is a developmental process in which epithelial cells acquire migratory characteristics, and in the process convert from a “cuboidal” epithelial structure into an elongated mesenchymal shape. We had shown previously that matrix metalloproteinase‐3 (MMP3) can stimulate EMT of cultured mouse mammary epithelial cells through a process that involves increased expression of Rac1b, a protein that stimulates alterations in cytoskeletal structure. We show here that cells treated with MMP‐3 or induced to express Rac1b spread to cover a larger surface, and that this induction of cell spreading is a requirement of MMP‐3/Rac1b‐induced EMT. We find that limiting cell spreading, either by increasing cell density or by culturing cells on precisely defined micropatterned substrata, blocks expression of characteristic markers of EMT in cells treated with MMP‐3. These effects are not caused by general disruptions in cell signaling pathways, as TGF‐β‐induced EMT is not affected by similar limitations on cell spreading. Our data reveal a previously unanticipated cell shape‐dependent mechanism that controls this key phenotypic alteration and provide insight into the distinct mechanisms activated by different EMT‐inducing agents. J. Cell. Biochem. 105: 25–33, 2008. © 2008 Wiley‐Liss, Inc.
Interplay between anion‐π and hydrogen bonding interactions
Authors: Escudero Daniel , Frontera Antonio , Quiñonero David , Deyà Pere M.
Published: May 2008

The interplay between two important noncovalent interactions involving aromatic rings is studied by means of high levelab initiocalculations. They demonstrate that synergistic effects are present in complexes where anion‐π and hydrogen bonding interactions coexist. These synergistic effects have been studied using the “atoms‐in‐molecules” theory and the Molecular Interaction Potential with polarization partition scheme. The present study examines how these two interactions mutually influence each other. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Family history of psychological problems in generalized anxiety disorder
Authors: McLaughlin Katie A. , Behar Evelyn , Borkovec T.D.
Published: May 2008

The current investigation examined self‐reported family history of psychological problems in a large sample of individuals diagnosed with generalized anxiety disorder (GAD) and nonanxious controls. The GAD participants were all individuals receiving cognitive–behavioral therapy as part of two large randomized clinical trials. Family history information was obtained from the Anxiety Disorders Interview Schedule‐Revised (ADIS‐R; DiNardo & Barlow, 1988). The results indicate that, compared to control participants, individuals with GAD were more likely to have family members with anxiety problems, but not other psychological problems. Possible mechanisms for the familial transmission of GAD are discussed. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64: 1–14, 2008.
Sox9, a key transcription factor of bone morphogenetic protein‐2‐induced chondrogenesis, is activated through BMP pathway and a CCAAT box in the proximal promoter
Authors: Pan Qiuhui , Yu Yongchun , Chen Qiongyu , Li Chunsheng , Wu Hong , Wan Yang , Ma Ji , Sun Fenyong
Published: May 2008

Mouse embryonic fibroblasts (MEFs) can be differentiated into fully functional chondrocytes in response to bone morphogenetic protein‐2 (BMP‐2). The expression of Sox9, a critical transcription factor for the multiple steps of chondrogenesis, has been reported to be upregulated during this process. But the molecular mechanisms by which BMP‐2 promotes chondrogenesis still remain largely unknown. The aim of the present study was therefore to investigate the underlying mechanism. In the MEFs, BMP‐2 efficiently induced Sox9 expression along with chondrogenic differentiation in a time‐ and dose‐dependent manner. SB203580, a specific inhibitor for p38 pathway, blocked BMP‐2‐induced chondrogenic differentiation as well as Sox9 expression and its transactivation of downstream genes. Forced expression of Smad6, a natural antagonist for BMP/Smad pathway, only inhibited Sox9 protein function without rendering any effects on its mRNA expression. A CCAAT box was identified in Sox9 promoter as thecis‐elements responsible for BMP‐2 stimulation. This study provides insight into the mechanisms underlying BMP‐2‐regulated Sox9 expression and activity in MEFs, and suggests differential roles of BMP‐2/p38 and BMP‐2/Smad pathways in modulating the function of Sox9 during chondrogenesis. J. Cell. Physiol. 217: 228–241, 2008. © 2008 Wiley‐Liss, Inc.
Age‐dependent impairment of HIF‐1α expression in diabetic mice: Correction with electroporation‐facilitated gene therapy increases wound healing, angiogenesis, and circulating angiogenic cells
Authors: Liu Lixin , Marti Guy P. , Wei Xiaofei , Zhang Xianjie , Zhang Huafeng , Liu Ye V. , Nastai Manuel , Semenza Gregg L. , Harmon John W.
Published: May 2008

Wound healing is impaired in elderly patients with diabetes mellitus. We hypothesized that age‐dependent impairment of cutaneous wound healing in db/db diabetic mice: (a) would correlate with reduced expression of the transcription factor hypoxia‐inducible factor 1α (HIF‐1α) as well as its downstream target genes; and (b) could be overcome by HIF‐1α replacement therapy. Wound closure, angiogenesis, and mRNA expression in excisional skin wounds were analyzed and circulating angiogenic cells (CACs) were quantified in db/db mice that were untreated or received electroporation‐facilitated HIF‐1α gene therapy. HIF‐1α mRNA levels in wound tissue were significantly reduced in older (4–6 months) as compared to younger (1.5–2 months) db/db mice. Expression of mRNAs encoding the angiogenic cytokines vascular endothelial growth factor (VEGF), angiopoietin 1 (ANGPT1), ANGPT2, platelet‐derived growth factor B (PDGF‐B), and placental growth factor (PLGF) was also impaired in wounds of older db/db mice. Intradermal injection of plasmid gWIZ‐CA5, which encodes a constitutively active form of HIF‐1α, followed by electroporation, induced increased levels of HIF‐1α mRNA at the injection site on day 3 and increased levels of VEGF, PLGF, PDGF‐B, and ANGPT2 mRNA on day 7. CACs in peripheral blood increased 10‐fold in mice treated with gWIZ‐CA5. Wound closure was significantly accelerated in db/db mice treated with gWIZ‐CA5 as compared to mice treated with empty vector. Thus, HIF‐1α gene therapy corrects the age‐dependent impairment of HIF‐1α expression, angiogenic cytokine expression, and CACs that contribute to the age‐dependent impairment of wound healing in db/db mice. J. Cell. Physiol. 217: 319–327, 2008. © 2008 Wiley‐Liss, Inc.
Potential of Monoraphidium sp. GK12 for energy‐saving astaxanthin production
Authors: Fujii Katsuhiko , Nakajima Hisatoshi , Anno Yuka
Published: May 2008

BACKGROUND: Astaxanthin is a chemical used in aquaculture, pharmaceuticals, foods, and cosmetics. Although Haematococcus pluvialis has been studied intensively as an astaxanthin producer, its cultivation requires stringent contamination control and nutrition levels, thus rendering astaxanthin production energy‐consuming. In the present study, the medium composition for cultivation of Monoraphidium sp. GK12, a newly isolated astaxanthin‐producing microalga, was improved and photoautotrophic cultivation was attempted to examine its potential for application to energy‐saving astaxanthin production.

RESULTS: A cost‐saving medium composed only of mineral salts was found to be suitable for photoautotrophic GK12 cultivation. A specific growth rate of 0.57 day−1 was obtained, which is higher than that of H. pluvialis. A high cell density of around 2.0 × 107 cells mL−1 was accomplished in outdoor batch cultivation, while outgrowth of contaminants was not observed. GK12 was also cultivated in a continuous photobioreactor, and the introduction of 1% CO2 stimulated GK12 growth and astaxanthin productivity.

CONCLUSION: Control of temperature, illumination, and culture pH is unnecessary for GK12 outdoor cultivation and no outgrowth of contaminants was observed, suggesting an advantage over H. pluvialis outdoor cultivation. Besides improving Haematococcus cultivation methods, research on GK12 as an alternative astaxanthin‐producer may contribute to the establishment of energy‐saving astaxanthin production. Copyright © 2008 Society of Chemical Industry
Combined use of waste materials—recovery of chitin from shrimp shells by lactic acid fermentation supplemented with date juice waste or glucose
Authors: Adour Lydia , Arbia Wassila , Amrane Abdeltif , Mameri Nabil
Published: May 2008

BACKGROUND: Chitin, a source of chitosan, was extracted from the teguments of white shrimp Parapenaeus longirostris, by means of Lactobacillus helveticus growing on date juice waste or glucose for comparison. A fermentor containing 10% (w/v) of shrimp shells was inoculated with a suspension of L. helveticus strain milano (10% v/v).

RESULTS: For an initial pH of 8.5–9.0 and a temperature of 30 °C, maximum deproteinization and demineralization were 76 and 53%, achieved for 80 and 300 g L−1 glucose, respectively. The level of demineralization increased to 60% for an increase in in temperature from 30 to 35 °C. The use of date juice, as an alternative to the use of a primary carbon source such as glucose, led at best to 44% demineralization, for 208 g L−1 of total sugar at 35 °C, and 91% deproteinization, for 80 g L−1 total sugar content at 30 °C.

CONCLUSION: Demineralization was not improved by the use of date juice, most likely due to its calcium content, which, during acidification, prevents the diffusion of calcium from the shells to the surrounding medium. Contrarily, the proteolytic activity of LAB appeared to be improved by the mineral content of date juice, leading to almost complete deproteinization of shrimp shells. Copyright © 2008 Society of Chemical Industry
Effect of dye auxiliaries on the kinetics of advanced oxidation UV/H2O2 of Acid Orange 7 (AO7)
Authors: Anglada Ángela , Rivero María J. , Ortíz Inmaculada , Urtiaga Ane
Published: May 2008

BACKGROUND: The effect of four dye‐auxiliary chemicals, typically employed in acid dyeing, on the performance of UV/H2O2 decolouration of the model non‐biodegradable dye C.I. Acid Orange 7 (AO7) was investigated. The initial concentration of AO7 was 0.150 g L−1, while the concentration of the auxiliary compounds (NaCl, Na2SO4, Na2CO3 and CH3COOH) was varied in the range 1–10 g L−1.

RESULTS: The negative influence of the presence of the dye‐auxiliary compounds studied on the decolouration rate of AO7 decreased in the following order: CH3COOH > Na2SO4 > NaCl > Na2CO3. Results were quantified in terms of the observed kinetic rate constant, kobs (s−1), of AO7 decolouration as a function of dye auxiliary chemical concentration. The decolouration rate of AO7 decreased as the concentration of dye‐auxiliary compound increased in the range 1–5 g L−1, while higher concentrations had a minor effect. Upon addition of 5 g L−1 of CH3COOH, NaCl and Na2SO4, the kinetic rate constant decreased by 39%, 30% and 12%, respectively.

CONCLUSIONS: It was concluded that the presence of NaCl, Na2SO4 and above all of CH3COOH should be considered in the design of the treatment of real dye‐bath effluents by UV/H2O2. Copyright © 2008 Society of Chemical Industry
RNAi‐mediated reversible opening of the blood‐brain barrier
Authors: Campbell Matthew , Kiang Anna‐Sophia , Kenna Paul F. , Kerskens Christian , Blau Christoph , O'Dwyer Laurence , Tivnan Amanda , Kelly Julie Anne , Brankin Brenda , Farrar Gwyneth‐Jane , Humphries Peter
Published: May 2008

Background

The blood‐brain barrier (BBB) contains tight junctions (TJs) which reduce the space between adjacent endothelial cells lining the fine capillaries of the microvasculature of the brain to form a selective and regulatable barrier.

Methods

Using a hydrodynamic approach, we delivered siRNA targeting the TJ protein claudin‐5 to the endothelial cells of the BBB in mice.

Results

We have shown a significant decrease in claudin‐5 mRNA levels 24 and 48 hours post‐delivery of siRNA, with levels of protein expression decreasing up to 48 hours post‐injection compared to uninjected, phosphate‐buffered saline (PBS)‐injected and non‐targeting siRNA‐injected mice. We observed increased permeability at the BBB to molecules up to 742 Da, but not 4400 Da, using tracer molecule perfusion and MRI analysis. To illustrate the functional efficacy of size‐selective and transient barrier opening, we have shown that enhanced delivery of the small neuropeptide thyrotropin‐releasing hormone (TRH) (MW 360 Da) to the brains of mice 48 hours post‐injection of siRNA targeting claudin‐5 significantly modifies behavioural output.

Conclusions

These data demonstrate that it is now possible to transiently and size‐selectively open the BBB in mice, allowing in principle the delivery of a wide range of agents for the establishment and treatment of experimental mouse models of neurodegenerative, neuropsychiatric and malignant diseases. Copyright © 2008 John Wiley & Sons, Ltd.
TLM nodal state estimator: An alternative method of initializing a two‐dimensional diffusion model
Authors: Koay A. L. , Wilkinson A. J. , Pulko S. H.
Published: May 2008

The transmission line matrix (TLM) method is an established technique for modelling thermal transients in heat transfer systems. However, initial and boundary conditions have always been slightly problematic, particularly when the boundary condition is specified as a temperature (Transmission Line Matrix (TLM) Techniques for Diffusion Applications. Gordon & Breach: London, 1998), for example, when the body of interest is suddenly exposed to a different temperature on its surface. In such a case the modelled solution contains additional dynamics that are associated with the two sub‐meshes in the TLM network and the two timesteps necessary for the temperature change to be fully communicated. These initialization problems are related to the fact that the boundary temperature in merely imposed as a fixed value on the network; the fundamental information‐carrying quantity, on the other hand, is the pulse, the thermal state of the body being represented by the distribution of pulses. Here, we aim to provide an alternative initialization approach, using nodal state estimation to derive pulse distributions from boundary and initial conditions specified by temperature. Consideration is given to the accuracy of the estimator by comparison with the first timestep solution proposed by Enders (Int. J. Numer. Model. 2002; 15:251–259). Copyright © 2008 John Wiley & Sons, Ltd.
Peptide inhibitors of MurD and MurE, essential enzymes of bacterial cell wall biosynthesis
Authors: Bratkovič Tomaž , Lunder Mojca , Urleb Uroš , Štrukelj Borut
Published: May 2008

Continuous development of antibacterial compounds with novel modes of action (accompanied by rationalization of chemotherapeutic prescription) is the best way to address the growing problem of antibiotic‐resistant infections. Numerous clinically important antibiotics interfere with peptidoglycan cell wall biosynthesis making this unique metabolic pathway a well validated target for antimicrobials. While nearly all of these antibiotics inhibit late stages of murein synthesis occurring on the extracellular side of plasma membrane, initial cytoplasmic steps have not been extensively exploited as drug targets. We performed affinity selection of peptides from phage‐displayed libraries against two essential bacterial enzymes MurD and MurE involved in the cytoplasmic synthesis of peptidoglycan monomer. Selected peptides were found to inhibit respective target enzymes in an in vitro assay with IC50 values of 140 μM to 1.5 mM. These peptides represent starting point for design of peptidomimetic lead compounds with the ultimate objective of small molecule chemotherapeutic development. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isolation and identification of a psychrotrophic Acinetobacter sp. CR9 and characterization of its alkaline lipase
Authors: Kasana Ramesh Chand , Kaur Baljinder , Yadav Sudesh Kumar
Published: May 2008

Forty three psychrotrophic bacteria were isolated from soil samples collected from Chandra river in sub‐alpine region of western Himalaya, India. Among these, 11 isolates were found positive for lipase production at low temperature. Of 11 isolates, CR9 produced largest zone of clearance on plate assay and was able to produce lipase under wide range of pH. The isolate CR9 was identified as Acinetobacter sp. based on morphological and physiochemical characterization and 16S rRNA gene sequencing analysis. According to 16S rRNA gene sequencing data the closest phylogenetic neighbor for strain CR9 was Acinetobacter lwoffii (98.9%). The partially purified lipase from strain CR9 exhibited maximum activity at temperature 40 °C and pH optima at 8.0. Cu2+, Mo2+, Mg2+, Zn2+, phenylmethanesulfonyl fluoride (PMSF), dithiothreitol (DTT) and β‐mercaptoethanol (2‐ME) enhanced the enzyme activity, whereas Ca2+ and ethylenediaminetetraacetic acid (EDTA) had inhibitory effect. Lipase hydrolyzed wide range of short chain fatty acid esters of p‐nitrophenyl. The organism CR9 also hydrolyzed tributyrin, Tween 80, soybean oil, mustard oil and olive oil. The results highlight the relevance of unexplored microbes from cold environments of western Himalaya for the isolation of novel lipase producing bacteria. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Biosorption of copper by yeast, Loddermyces elongisporus, isolated from industrial effluents: its potential use in wastewater treatment
Authors: Rehman Abdul , Farooq Hina , Hasnain Shahida
Published: May 2008

The present study is aimed at assessing the ability of metal resistant yeast, Loddermyces elongisporus, to uptake metal from liquid medium. The minimum inhibitory concentration of Cu2+ against Loddermyces elongisporus ranged between 2.2–2.3 mg/l. The yeast could also tolerate Zn2+ (2.9 mg/l), Hg2+ (2.4 mg/l), Ni2+ (2.2 mg/l), Cr6+ (2.0 mg/l), Pb2+ (1.1 mg/l), and Cd2+ (0.8 mg/l). The yeast isolate showed typical growth curves but lag and log phases extended in the presence of copper. Yeast isolate showed optimum growth at 30 ºC and pH 8. Metal processing ability of the isolate was determined in a medium containing 0.1 mg/l of Cu2+. Loddermyces elongisporus could reduce Cu2+ 15%, 26%, 39%, 50%, 60%, 67%, 75% and 81% from the medium after 6, 12, 18, 24, 30, 48, 72 and 96 hours, respectively. L. elongisporus could also efficiently remove 80% copper from the medium after 96 h and was able to remove Cu2+ 60% and 77% from the wastewater after 4 and 8 d, respectively. The metal binding ability suggests possibility of using this yeast strain for removal of copper from metal contaminated wastewater. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Susceptibility of local Agrobacterium tumefaciens strains to streptomycetes isolates from Jordan soils
Authors: Saadoun Ismail , Al‐Momani Fouad
Published: May 2008

Five strains of Agrobacterium tumefaciens were isolated and characterized from 12 different plant tumors. The susceptibility of these phytopathogens to antibiotics and to soil Streptomyces isolates was tested. Among the 90 Streptomyces isolates, only 12 were able to inhibit the growth of at least one A. tumefaciens strain. Four strains of A. tumefaciens were susceptible to streptomycin and cefotaxime. In addition, Streptomyces 404 strain was able to inhibit the growth of four strains of the Agrobacterium pathogens with an inhibition zone diameter ranged between 10 and 16 mm. The strong inhibitory effects of Streptomyces 404 strain on A. tumefaciens suggest the use of this strain as a promising agent to control crown gall disease. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fphog1, a HOG‐type MAP kinase gene, is involved in multistress response in Fusarium proliferatum
Authors: Ádám Attila L. , Kohut Gábor , Hornok László
Published: May 2008

ΔFphog1 mutants of Fusarium proliferatum obtained by targeted gene disruption of Fphog1, an orthologue of the Saccharomyces cerevisiae hog1 MAPK gene showed increased sensitivity towards different abiotic stressors including UV‐irradiation, heat, salt, osmotic and hydrogen peroxide treatments. Incubation of the ΔFphog1 mutants under hyperosmotic conditions was accompanied with prolonged growth arrest, inhibition of conidial germination, morphological abnormalities and time‐dependent increase of the cell death rate. The wild type Fphog1 gene, under the control of its own promoter, was able to rescue the multistress sensitivity of the mutant strain. Real time qPCR data demonstrated that under salt and sorbitol stress conditions the Fphog1 gene is not subject of transcriptional regulation. Levels of reactive oxygen species (ROS), mitochondrial membrane permeability transition, nuclear disintegration and DNA fragmentation, indicators of programmed cell death (PCD) all showed significant increases under osmotic stress conditions in the ΔFphog1 mutant in comparison to the wild type strain. These results suggest that an important function of Fphog1 is attenuating apoptotic phenotypes under salt and sorbitol stressors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)