bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant property and production of exopolysaccharide from Armillaria mellea in submerged cultures: Effect of culture aeration rate
Authors: Lung Ming Y. , Hsieh Chih W.
Published: April 2011

Effects of culture aeration rate on production and antioxidant property of exopolysaccharide (EPS) by Armillaria mellea were investigated in a 5‐L stirred‐tank bioreactor where an optimal biomass aeration rate of 1.2 vvm with 0.22 g/g cell yield and 0.6 vvm EPS formation rate with 7.66 mg/g product yield were achieved. A two‐stage aeration process to maximize the biomass and EPS productions proceeded with a 1.55‐fold enhancement (from 4.28 to 6.65 g/L) in biomass formation and a 2.68‐fold enhancement (from 86.9 to 233.2 mg/L) in the EPS production, as compared with those from the aeration rate of 0.3 vvm. The molecular weights of EPS in cultures of different aeration rates are closely correlated with their protein/polysaccharide ratios (R2=0.830) and EC50 (EC50, the effective concentration where the antioxidant property is 50%) values in antioxidant activity (R2=0.960), reducing power (R2=0.894) and chelating ability (R2=0.954). EPS from the two‐stage aeration rate culture shows a strong antioxidant property by the conjugated diene method, reducing power and chelating ability on ions. Therefore, we present results to regulate and to optimize A. mellea cultures to efficiently produce biomass and EPS. The fermented EPS has the potential to be used as for antioxidant‐related functional foods and pharmaceutical industries.
Depression of cortical activity in humans by mild hypercapnia
Authors: Thesen Thomas , Leontiev Oleg , Song Tao , Dehghani Nima , Hagler Donald J , Huang Mingxiong , Buxton Richard , Halgren Eric
Published: April 2011

The effects of neural activity on cerebral hemodynamics underlie human brain imaging with functional magnetic resonance imaging and positron emission tomography. However, the threshold and characteristics of the converse effects, wherein the cerebral hemodynamic and metabolic milieu influence neural activity, remain unclear. We tested whether mild hypercapnia (5% CO2) decreases the magnetoencephalogram response to auditory pattern recognition and visual semantic tasks. Hypercapnia induced statistically significant decreases in event‐related fields without affecting behavioral performance. Decreases were observed in early sensory components in both auditory and visual modalities as well as later cognitive components related to memory and language. Effects were distributed across cortical regions. Decreases were comparable in evoked versus spontaneous spectral power. Hypercapnia is commonly used with hemodynamic models to calibrate the blood oxygenation level‐dependent response. Modifying model assumptions to incorporate the current findings produce a modest but measurable decrease in the estimated cerebral metabolic rate for oxygen change with activation. Because under normal conditions, low cerebral pH would arise when bloodflow is unable to keep pace with neuronal activity, the cortical depression observed here may reflect a homeostatic mechanism by which neuronal activity is adjusted to a level that can be sustained by available bloodflow. Animal studies suggest that these effects may be mediated by pH‐modulating presynaptic adenosine receptors. Although the data is not clear, comparable changes in cortical pH to those induced here may occur during sleep apnea, sleep, and exercise. If so, these results suggest that such activities may in turn have generalized depressive effects on cortical activity. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Efficacy and safety of entecavir versus adefovir in chronic hepatitis B patients with hepatic decompensation: A randomized, open-label study
Authors: Liaw Yun-Fan , Raptopoulou-Gigi Maria , Cheinquer Hugo , Sarin Shiv Kumar , Tanwandee Tawesak , Leung Nancy , Peng Cheng-Yuan , Myers Robert P. , Brown Robert S. , Jeffers Lennox , Tsai Naoky , Bialkowska Jolanta , Tang Shijie , Beebe Suzanne , Cooney Elizabeth
Published: April 2011

Abstract:

A randomized, open-label comparative study of entecavir versus adefovir therapy was performed in subjects with chronic hepatitis B who had hepatic decompensation (Child-Turcotte-Pugh score ≥7). Adult subjects were randomized and treated (n = 191) with entecavir 1.0 mg or adefovir 10 mg daily for up to 96 weeks from the date of last subject randomization. Subjects were positive or negative for hepatitis B e antigen and experienced or naive for treatment with nucleos(t)ide analogues. The primary efficacy endpoint was the mean reduction in serum hepatitis B virus (HBV) DNA, as determined by polymerase chain reaction, at week 24, adjusted for baseline HBV DNA and lamivudine resistance status by linear regression analysis. Entecavir demonstrated superiority to adefovir for this endpoint (treatment difference 1.74 log10 copies/mL [95% confidence interval −2.30, −1.18]; P < 0.0001). The entecavir group showed a greater change from baseline in HBV DNA at all time points through week 48 and a higher proportion of subjects who achieved HBV DNA < 300 copies/mL at weeks 24 (entecavir 49%; adefovir 16%; P < 0.0001) and 48 (entecavir 57%; adefovir 20%; P < 0.0001). Approximately two-thirds of subjects in both groups showed improvement/stabilization in Child-Turcotte-Pugh status. Model for End-Stage Liver Disease score change at week 48 was −2.6 for entecavir and −1.7 for adefovir. Adverse event rates were comparable between groups. Cumulative hepatocellular carcinoma rates were 12% for entecavir and 20% for adefovir. Cumulative death rates were 23% for entecavir and 33% for adefovir. Week 24 mortality rates were 12% for both groups. Conclusion: Entecavir demonstrated superior virologic efficacy to adefovir in a population of patients with chronic hepatitis B who had hepatic decompensation. Biochemical and clinical benefits were also demonstrated. Entecavir was well tolerated, and early mortality rates were consistent with rates observed in similar populations treated with lamivudine. (HEPATOLOGY 2011;)
International stock market indices comovements: a new look
Authors: Madaleno Mara , Pinho Carlos
Published: April 2011

This study accounts for the time‐varying pattern of price shock transmission, exploring stock market linkages using continuous time wavelet methodology. In order to sustain and improve previous results regarding correlation analysis between stock market indices, namely FTSE100, DJIA30, Nikkei225 and Bovespa, we extend here such analysis using the Coherence Morlet Wavelet, considering financial crisis episodes.

Results indicate that the relation among indices was strong but not homogeneous across scales, that local phenomenon's are more felt than others in these markets and that there seems to be no quick transmission through markets around the world, but yes a significant time delay. The relation among these indices has changed and evolved through time, mostly due to financial crisis that occurred at different time periods. Results also favor the view that geographically and economically closer markets exhibit higher correlation and more short run comovements among them. Strong comovement is mostly confined to long‐run fluctuations favoring contagion analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Toward the development of an artificial cornea: Improved stability of interpenetrating polymer networks
Authors: Hartmann Laura , Watanabe Kenji , Zheng Luo Luo , Kim Chang‐Yeon , Beck Stayce E. , Huie Philip , Noolandi Jaan , Cochran Jennifer R. , Ta Christopher N. , Frank Curtis W.
Published: April 2011

A novel interpenetrating network (IPN) based on poly(ethylene glycol) (PEG) and poly(acrylic acid) was developed and its use as an artificial cornea was evaluated in vivo. The in vivo results of a first set of corneal inlays based on PEG‐diacrylate precursor showed inflammation of the treated eyes and haze in the corneas. The insufficient biocompatibility could be correlated to poor long‐term stability of the implant caused by hydrolytic degradation over time. Adapting the hydrogel chemistry by replacing hydrolysable acrylate functionalities with stable acrylamide functionalities was shown to increase the long‐term stability of the resulting IPNs under hydrolytic conditions. This new set of hydrogel implants now shows increased biocompatibility in vivo. Rabbits with corneal inlay implants are healthy and have clear cornea and non‐inflamed eyes for up to 6 months after implantation. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
P2Y11 impairs cell proliferation by induction of cell cycle arrest and sensitizes endothelial cells to cisplatin‐induced cell death
Authors: Xiao Zhilin , Yang Mei , Lv Qingshan , Wang Wenmeng , Deng Minjie , Liu Xueting , He Qing , Chen Xiaobin , Chen Meifang , Fang Li , Xie Xiumei , Hu Jinyue
Published: April 2011

Extracellular ATP mediates a wide range of physiological effects, including cell proliferation, differentiation, maturation, and migration. However, the effect of ATP on cell proliferation has been contradictory, and the mechanism is not fully understood. In the current study, we found that extracellular ATP significantly inhibited the proliferation of human umbilical vein endothelial cells (HUVECs) and human aortic endothelial cells (HAECs). Treatment with ATP did not induce cell apoptosis but instead induced cell cycle arrest in S phase. ATP induced the phosphorylation of ERK1/2, but the ERK inhibitors, U0126 and PD9809, did not regulate the inhibition of cell proliferation induced by ATP. However, ATP‐induced inhibition of cell proliferation was blocked by suramin, a nonspecific antagonist of the P2Y receptors, and endothelial cells expressed P2Y11, a P2Y receptor that specifically binds ATP. Moreover, the down‐regulation of P2Y11 by RNA interference not only reversed the inhibition of cell proliferation but also ameliorated cell cycle arrest in S phase. In addition, P2Y11 sensitized endothelial cells to cisplatin‐induced cell death by down‐regulation of the expression of Bcl‐2. Taken together, these results suggest that extracellular ATP impairs cell proliferation by triggering signaling to induce cell cycle arrest and sensitizes cell to death via P2Y11 in endothelial cells. J. Cell. Biochem. 112: 2257–2265, 2011. © 2011 Wiley‐Liss, Inc.
Isolation and characterization of squamous carcinoma cells resistant to photodynamic therapy
Authors: Milla Laura N. , Cogno Ingrid S. , Rodríguez Matías E. , Sanz‐Rodríguez Francisco , Zamarrón Alicia , Gilaberte Yolanda , Carrasco Elisa , Rivarola Viviana A. , Juarranz Ángeles
Published: April 2011

Photodynamic therapy (PDT) employing methyl δ‐aminolevulinic acid (Me‐ALA), as a precursor of the photosensitizer protoporphyrin IX (PpIX), is used for the treatment of non melanoma cutaneous cancer (NMCC). However, one of the problems of PDT is the apparition of resistant cell populations. The aim of this study was to isolate and characterize squamous carcinoma cells SCC‐13 resistant to PDT with Me‐ALA. The SCC‐13 parental population was submitted to successive cycles of Me‐ALA‐PDT and 10 resistant populations were finally obtained. In parental and resistant cells there were analyzed the cell morphology (toluidine blue), the intracellular PpIX content (flow cytometry) and its localization (fluorescence microscopy), the capacity of closing wounds (scratch wound assay), the expression of cell‐cell adhesion proteins (E‐cadherin and β‐catenin), cell‐substrate adhesion proteins (β1‐integrin, vinculin and phospho‐FAK), cytoskeleton proteins (α‐tubulin and F‐actin) and the inhibitor of apoptosis protein survivin, in the activated form as phospho‐survivin (indirect immunofluorescence and Western blot). The results obtained indicate that resistant cells showed a more fibroblastic morphology, few differences in intracellular content of the photosensitizer, higher capacity of closing wounds, higher number of stress fibers, more expression of cell‐substrate adhesion proteins and higher expression of phospho‐survivin than parental cells. These distinctive features of the resistant cells can provide decisive information to enhance the efficacy of Me‐ALA applications in clinic dermatology. J. Cell. Biochem. 112: 2266–2278, 2011. © 2011 Wiley‐Liss, Inc.
The role of TWIST as a regulator in giant cell tumor of bone
Authors: Singh Shalini , Mak Isabella W.Y. , Cowan Robert W. , Turcotte Robert , Singh Gurmit , Ghert Michelle
Published: April 2011

Giant cell tumor of bone (GCT) is an aggressive tumor consisting of multinucleated osteoclast‐like giant cells and proliferating osteoblast‐like stromal cells. Our group has reported that the stromal cells express high levels of the bone resorbing matrix metalloproteinase (MMP)‐13, and that this expression is regulated by the osteoblast transcription factor Runx2. The purpose of this study was to determine the upstream regulation of Runx2 in GCT cells. Using GCT stromal cells obtained from patient specimens, we demonstrated that TWIST, a master osteogenic regulator, was highly expressed in all GCT specimens. TWIST overexpression downregulated Runx2 expression whereas TWIST siRNA knockdown resulted in Runx2 and MMP‐13 upregulation. Interestingly, cells obtained from a GCT lung metastasis showed a reverse regulatory pattern between TWIST and Runx2. In mutational analysis, we revealed a point mutation (R154S) at the Helix2 domain of TWIST. This TWIST mutation may be an essential underlying factor in the development and pathophysiology of these tumors in that they lead to inappropriate TWIST downregulation of Runx2, arrested osteoblastic differentiation, and the maintenance of an immature and neoplastic phenotype. J. Cell. Biochem. 112: 2287–2295, 2011. © 2011 Wiley‐Liss, Inc.
In‐source fragmentation and accurate mass analysis of multiclass flavonoid conjugates by electrospray ionization time‐of‐flight mass spectrometry
Authors: Abrankó László , García‐Reyes Juan F. , Molina‐Díaz Antonio
Published: April 2011

In‐source collision‐induced dissociation (CID) fragmentation features of multiclass flavonoid glycoconjugates were examined using liquid chromatography electrospray time‐of‐flight mass spectrometry. Systematic experiments were performed to search for optimal conditions for in‐source fragmentation in both positive and negative ion modes. The objective of the study was to attain uniformly appropriate conditions for a wide range of analytes independently of the aglycone, the attached sugar part and the type of bond between the aglycone and the glycan moieties (O‐ or C‐glycosides). Studied substances included representatives of flavonols, flavones, flavanones and anthocyanins and, regarding their glycan parts, mono‐, di‐ and triglycosides with varying distribution of carbohydrate moieties (di‐O‐glycosides, O‐diglycosides, O,C‐diglycosides). The breakdown properties of the analytes along with the abundances of the characteristic diagnostic ions required for structural elucidation of complex flavonoid derivatives were evaluated. An optimized value was found for the instrument parameter (fragmentor voltage) affecting the in‐source CID fragmentation of the analytes [230 V (ESI+) and 330 V (ESI−)]. Thus, appropriate performance in terms of both highly sensitive full‐scan acquisition and fragmentation information was obtained for all the investigated flavonoids. In addition, singularities in the abundance of selected diagnostic ions (e.g. Y0, Y1 and Y*) due to variations in the interglycosidic linkage (rutinoside–neohesperidoside) in the glycan part were found and are also evaluated and discussed in detail. The combination of in‐source CID fragmentation with high mass accuracy MS detection establishes a working basis for the development of versatile and useful LC‐MS methods for wide‐scope screening, non‐targeted detection and tentative identification of flavonoid derivatives. Copyright © 2011 John Wiley & Sons, Ltd.
Torque teno virus in fecal samples of patients with gastroenteritis: Prevalence, genogroups distribution, and viral load
Authors: Pinho‐Nascimento Carlos Augusto , Leite José Paulo Gagliardi , Niel Christian , Diniz‐Mendes Leonardo
Published: April 2011

Torque teno virus (TTV, genus Alphatorquevirus, family Anelloviridae) is a DNA virus, highly prevalent in populations from around the world. TTV isolates have been classified into five main phylogenetic groups (1–5) showing a large genetic distance between them. The presence of TTV has been detected in feces. However, whether all five TTV genogroups are excreted in feces and the frequency of these events are presently unknown. The presence of TTV DNA was assessed in feces from 135 Brazilian (0–90 years old) patients with gastroenteritis by using three PCR methods, including real‐time PCR. One hundred twenty one (91.1%) samples were positive with at least one method. Using a genogroup‐specific assay, it was shown that all genogroups were present. Thirty‐seven (27.4%), 27 (20.0%), 57 (42.2%), 29 (21.5%), and 33 (24.4%) fecal samples contained TTV isolates belonging to genogroups 1–5, respectively. Coinfections with two, three, four, and five TTV genogroups were found in 23 (17.0%), 15 (11.1%), 7 (5.2%), and 7 (5.2%) fecal samples, respectively. Thus, 52 (38.5%) samples contained more than one TTV genogroup. Viral loads ranged from 2.6 to 6.5 log genome equivalents per gram of feces. However, only moderate variations of viral load were noted depending on genogroup and number of coinfecting TTV genogroups. These results show a high prevalence and a diversity of TTV isolates in feces. J. Med. Virol. 83:1107–1111, 2011. © 2011 Wiley‐Liss, Inc.
Presence of occult HBV, but near absence of active HBV and HCV infections in people infected with HIV in rural South Africa
Authors: Barth Roos E. , Huijgen Quirine , Tempelman Hugo A. , Mudrikova Tania , Wensing Annemarie M.J. , Hoepelman Andy I.M.
Published: April 2011

Human immunodeficiency (HIV), hepatitis B (HBV), and hepatitis C (HCV) viruses are endemic in Sub‐Saharan Africa, but data regarding the prevalence of hepatitis co‐infections in HIV‐positive individuals residing there are limited. The aim of the study was to determine the prevalence of HBV, HCV, and occult HBV (presence of HBV‐DNA in the absence of HBsAg) in a rural, South African cohort. The results were compared to various ethnic groups in a Dutch cohort of people infected with HIV. Antiretroviral‐naïve individuals with HIV from both a rural South African clinic (n = 258), and a Dutch University hospital (n = 782), were included. Both serological (HBV and HCV) and molecular (occult HBV) assays were performed. Logistic regression analysis was used to define independent predictors of a hepatitis co‐infection. HBV and HCV prevalence rates in the South African cohort were exceptionally low (0.4%, 1/242 and 0.8%, 2/242, respectively), compared to those observed in Caucasians (HBV 4.4% and HCV 10.9%) and African immigrants (HBV 8.9% and HCV 4.8%). Conversely, occult HBV was observed in a considerable proportion (10%, 6/60) of South African patients who were anti‐HBc‐positive but HBsAg‐negative. Occult infections were less frequent in Caucasians and Africans in the Dutch cohort (3.2% and 1.4%, respectively). Independent predictors for occult HBV were not identified, but a trend towards more occult HBV at lower CD4 counts was observed. Local HBV/HCV prevalence data are needed to optimize vaccination and antiretroviral treatment strategies. Occult HBV in patients with HIV may be missed regularly when molecular analyses are not available. J. Med. Virol. 83:929–934, 2011. © 2011 Wiley‐Liss, Inc.
High prevalence of significant liver fibrosis and cirrhosis in chronic hepatitis B patients with normal ALT in central Europe
Authors: Göbel Thomas , Erhardt Andreas , Herwig Mathias , Poremba Christopher , Baldus Stephan Ernst , Sagir Abdurrahman , Heinzel‐Pleines Ulrike , Häussinger Dieter
Published: April 2011

The indication for antiviral treatment of patients with chronic hepatitis B is based on serum HBV DNA levels, transaminases, and histological grade and stage. The relation of liver fibrosis and inflammation to ALT activity in chronic hepatitis B infection was investigated in a non‐endemic, European setting. A total of 253 patients with chronic hepatitis B who had undergone liver biopsy at the Clinic of Gastroenterology, Hepatology, and Infectious Diseases, Düsseldorf, Germany over the past 19 years (1990–2009) were evaluated. Thirty‐nine patients had persistently normal transaminases, 86 patients had ALT with 1–2 × ULN (upper limit of normal) and 128 patients had ALT >2 × ULN. Liver fibrosis or inflammation was defined as significant for stages or grades ≥ 2 according to the Desmet/Scheuer score. Significant liver fibrosis (F ≥ 2) was found in 36%, cirrhosis in 18%, and significant inflammation (G ≥ 2) in 27% of patients with normal transaminases. There was no difference in the stage of liver fibrosis and the frequency of cirrhosis between patients with normal and elevated transaminases. The most important factor associated with the presence of cirrhosis in multivariate analysis was age ≥40 years (P < 0.003). If concomitant factors like elevated GGT or male sex were furthermore present high prevalences of significant liver disease were found. The data indicate that, in a European setting, patients with chronic hepatitis B infection, and normal transaminases frequently have significant liver fibrosis or cirrhosis. Therefore, liver biopsy or liver stiffness measurement (LSM) should be performed in these patients to determine the stage of liver fibrosis. J. Med. Virol. 83:968–973, 2011. © 2011 Wiley‐Liss, Inc.
Comparative evaluation of different DNA extraction methods for HPV genotyping by linear array and INNO‐LiPA
Authors: Donà Maria Gabriella , Benevolo Maria , Pimpinelli Fulvia , Battista Mara , Rollo Francesca , Stivali Francesca , Moscarelli Antonella , Giuliani Massimo , Di Carlo Aldo , Vocaturo Amina
Published: April 2011

In order to investigate the influence of DNA extraction on two PCR‐based HPV genotyping tests (Linear Array, Roche and INNO‐LiPA Extra, Innogenetics), three different procedures were used to purify DNA from 28 cervico‐vaginal samples tested previously by the Hybrid Capture 2: the AmpliLute Liquid Media Extraction kit (Roche), the QIAamp DNA Blood mini kit (QIAGEN), and the NucliSENS EasyMAG automated platform (bioMérieux). All HC2‐positive samples were found positive by both assays, independently of the extract used. Type‐specific concordance (i.e., identical HPV type‐specific profile in all the extracts of the same sample) was observed in 55% and 75% of the cases testing samples by the Linear Array and the INNO‐LiPA, respectively. Using the DNA extracted with the two manual methods the results were concordant in 75% of the cases both for the Linear Array and the INNO‐LiPA. When comparing the Linear Array results obtained on either of the two manual extracts with those obtained following automated extraction, 65% of the samples showed type‐specific concordance in both cases. The INNO‐LiPA results were concordant in 80% of the cases comparing the AmpliLute versus the automated extract, while concordant results were observed in 90% of the cases when comparing the QIAGEN versus the automated extract. In conclusion, the Linear Array and INNO‐LiPA results are affected by the method of DNA extraction. Consequently, different HPV type‐specific profiles may be observed using different extracts of the same sample. The use of consistent protocols for DNA purification is a priority to guarantee intra‐assay reproducibility over time. J. Med. Virol. 83:1042–1047, 2011. © 2011 Wiley‐Liss, Inc.
Mass diffusion‐based separation of sugars in a microfluidic contactor with nanofiltration membranes
Authors: Kolfschoten Ruben C. , Janssen Anja E. M. , Boom Remko M.
Published: April 2011

Processes such as chromatographic separation and nanofiltration can remove low molecular weight sugars from liquid mixtures of oligosaccharides. As an alternative for the separation of such liquid mixtures, we studied mass diffusion separation of such sugars in a microfluidic device with incorporated nanofiltration membranes. This separation method is based on differences between diffusivities of components and does not require high transmembrane pressures. The effects of channel depth and flow rate were studied in experiments. The key parameters selectivity and rejection increased with increasing channel depth due to increased external mass transfer limitations. Among the studied membranes, the obtained selectivities and rejections correlated to the specified retention values by the manufacturers. Compared to more conventional nanofiltration where high pressure forces solutes through membranes, we obtained corresponding selectivities and fluxes of only an order of magnitude smaller. Simulated results indicated that with optimized microchannel and membrane dimensions, the presented separation process can compete with currently available separation technologies.
Selective recognition of 4‐nitrophenol from aqueous solution by molecularly imprinted polymers with functionalized tetratitanate whisker composites as support
Authors: Guan Wei , Pan Jianming , Wang Xue , Hu Wei , Xu Longcheng , Zou Xiaohua , Li Chunxiang
Published: April 2011

Three kinds of molecularly imprinted polymers (MIPs) were obtained with surface molecular imprinting technique on functionalized potassium tetratitanate whisker (F‐PTW). The results of adsorption experiments indicated that MIP prepared using PTW modified with N‐(2‐aminoethyl)‐3‐(trimethoxysilyl)propylamine (AAPTS) (F‐PTW A) as support [MIP(1)] was superior to the other two polymers, then MIP(1) was selected to analyze the 4‐nitrophenol (4‐NP) adsorption process from aqueous solution in this study. AAPTS offered hydrophilic exterior that allowed to self‐assemble with the template 4‐NP through intermolecular interaction rather than based on the interactions between the functional monomers and template. Equilibrium adsorption data were analyzed by the Langmuir and Freundlich isotherm models at various temperatures. Kinetic properties were successfully investigated by pseudo‐first‐order model, pseudo‐second‐order model, intraparticle diffusion equation, initial adsorption rate, half‐adsorption time. A diffusion‐controlled process as the essential adsorption rate‐controlling step was also proposed. The performance of such imprinted polymer was further demonstrated by high‐performance liquid chromatography, and the results showed that the selectivity of MIP(1) exhibited higher affinity for template 4‐NP over competitive phenolic compounds than that of non‐imprinted polymer NIP(1). MIP(1) could be reused four times without significant loss in the adsorption capacity.
CHARACTERIZING VARIATIONS IN SOIL PARTICLE‐SIZE DISTRIBUTION ALONG A GRASS–DESERT SHRUB TRANSITION IN THE ORDOS PLATEAU OF INNER MONGOLIA, CHINA
Authors: Jin Z. , Dong Y. S. , Qi Y. C. , Liu W. G. , An Z. S.
Published: April 2011

The application of fractal geometry to describe soil degradation and dynamics is becoming a useful tool for better understanding of the performance of soil systems. In this study, four different land cover types, which represent a sequence of grass–desert shrub transition and a gradient of desertification, were selected, and soils at depths of 0–10, 10–20 and 20–40 cm were sampled in the Ordos Plateau of Inner Mongolia, PR China. The fractal theory was used to analyse the soil particle‐size distribution (PSD) and its variations. The results showed that (i) vegetation conversion and desertification significantly changed the soil PSD. During the desertification process, soil coarse fractions that ranged from 250 to 100 µm significantly increased, whereas fine fractions lower than 50 µm significantly decreased (p < 0·01); (ii) fractal model of the accumulative volume particle‐size distribution is appropriate, and fractal dimensions (Dm) of soil PSD significantly decreased along the sequence of grass–desert shrub transition; (iii) Dm is more sensitive to the desertification process, and therefore, we suggest Dm other than soil texture and soil organic carbon as a reliable parameter to reflect the soil environment change induced by desertification. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of pH‐Sensitive Poly(β‐amino ester)‐graft‐poly(ethylene glycol) and its Usefulness as a pH‐Sensor and Protein Carrier
Authors: Kim Min Sang , Gao Guang Hui , Kang Seong Woo , Lee Doo Sung
Published: April 2011

In this study, some possible biomedical applications of a pH‐sensitive and amphiphilic copolymer as a pH sensor and protein delivery system are reported. PAE‐g‐PEG was used as a pH‐sensitive polymer that can exhibit a sharp pH‐dependent transition. Various fluorescent dyes including pyrene and RITC can be used to label the pH‐sensitive polymer PAE‐g‐PEG, which was evaluated for protein encapsulation. pH‐sensing was possible by observing excimer formation of the labeled pyrene via pH‐dependent expansion of the polymeric chain. Also, it was confirmed that FITC‐BSA could be entrapped in RITC‐labeled pH‐sensitive micelles of PAE‐g‐PEG by FRET. As a result, PAE‐g‐PEG can be a pH sensor and carrier for protein delivery.

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Microphase Separation of Phenylene Oligomers with Polymeric Side Chains: A Dissipative Particle Dynamics Study
Authors: Yıldırım Erol , Yurtsever Mine , Kenarlı Burcu , Demirel A. Levent
Published: April 2011

The microphase‐separated morphologies of p‐phenylene oligomers with POx, PCL, PS, and PEO side chains are studied using DPD simulations. It is shown that the microphase‐separated morphologies depend significantly on the degree of chemical incompatibility between the components as indicated by the Flory‐Huggins interaction parameters. The good agreement of the microphase separated morphologies as simulated by DPD with the experimentally determined thin film morphologies suggests that DPD can produce convincing morphological information at the nanoscale. The results show that grafting of polymeric side chains can be an important tool to control the morphology of polymers with a rigid backbone.

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Transfer of axillary nerve branches to reconstruct elbow extension in tetraplegics: A laboratory investigation of surgical feasibility
Authors: Bertelli Jayme Augusto , Tacca Cristiano Paulo , Winkelmann Duarte Elisa Cristiana , Ghizoni Marcos Flávio , Duarte Hamilton
Published: April 2011

In spinal cord injuries at the C6 level, elbow extension is lost and needs reconstruction. Traditionally, elbow extension has been reconstructed by muscle transfers, which improve function only moderately. We have hypothesized that outcomes could be ameliorated by nerve transfers rather than muscle transfers. We anatomically investigated nerve branches to the teres minor and posterior deltoid as donors for transfer to triceps motor branches. In eight formalin‐fixed cadavers, the axillary nerve, the teres minor branch, the posterior deltoid branch, the triceps long and upper medial head motor branches, and the thoracodorsal nerve were dissected bilaterally, their diameters measured and their myelinated fibers counted. To simulate surgery, using an axillary approach in two fresh cadavers, we transferred the teres minor or the posterior deltoid branch to the triceps long head and to the thoracodorsal nerve. The posterior division of the axillary nerve gave off the teres minor motor branch and then the branch to the posterior deltoid, terminating as the superior lateral brachial cutaneous nerve. The diameters of the teres minor motor branch, posterior deltoid, triceps long and upper medial head branches, and the thoracodorsal nerve all were ∼2 mm, with minimal variation. The nerves varied little in their numbers of myelinated fibers, being consistently about 1,000. Via an axillary approach, either the teres minor or the posterior deltoid branch could be transferred directly to the thoracodorsal nerve or to triceps branches without any tension. © 2011 Wiley‐Liss, Inc. Microsurgery, 2011.
An augmented cohesive zone element for arbitrary crack coalescence and bifurcation in heterogeneous materials
Authors: Fang X. J. , Yang Q. D. , Cox B. N. , Zhou Z. Q.
Published: April 2011

We demonstrate that traditional cohesive zone (CZ) elements cannot be accurate when used in conjunction with solid elements with arbitrary intra‐element cracking capability, because they cannot capture the load transfer between cohesive interfaces and the solid elements when crack bifurcation or coalescence occurs. An augmented cohesive zone (ACZ) element based on the augmented finite element method formulation is therefore proposed. The new element allows for arbitrary separation of the cohesive element in accordance with the crack configuration of the abutting solid elements, thus correctly maintaining the non‐linear coupling between merging or bifurcating cracks. Numerical accuracy and effectiveness of the proposed ACZ element are demonstrated through several examples. Copyright © 2011 John Wiley & Sons, Ltd.
An efficient finite element time‐domain formulation for the elastic second‐order wave equation: A non‐split complex frequency shifted convolutional PML
Authors: Matzen René
Published: April 2011

The perfectly matched layer (PML) technique has demonstrated very high efficiency as absorbing boundary condition for the elastic wave equation recast as a first‐order system in velocity and stress in attenuating non‐grazing bulk and surface waves. This paper develops a novel convolutional PML formulation based on the second‐order wave equation with displacements as the only unknowns to annihilate spurious reflections from near‐grazing waves. The derived variational form allows for the use of e.g. finite element and the spectral element methods as spatial discretization schemes. A recursive convolution update scheme of second‐order accuracy is employed such that highly stable, effective time integration with the Newmark‐beta (implicit and explicit with mass lumping) method is achieved. The implementation requires minor modifications of existing displacement‐based finite element software, and the stability and efficiency of the proposed formulation is verified by relevant two‐dimensional benchmarks that accommodate bulk and surface waves. Copyright © 2011 John Wiley & Sons, Ltd.
Analysis of natural degradation of high‐density polyethylene lining using time‐dependent properties
Authors: Mbuge Duncan O. , Gumbe L.O. , Rading G.O.
Published: April 2011

The main objective of this study was to determine the service life of high‐density polyethylene lining when exposed to natural degradation in tropical climates using time‐dependant properties. The changes in material density, strength, and strain at fracture over the degradation period were determined. Optical micrographs were obtained to track the changes in the material during aging. An exponential decay equation was developed that estimates of the service life of the high‐density polyethylene lining. It was concluded that most of the degradation of the material takes place in the first few months of installation and that both the density and mechanical strength of the material increased in the course of degradation, whereas the fracture strain reduced over time. It was concluded that the most important factor that determines the lifespan of the liner is the ability to maintain high strains. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Laser‐fired contact optimization in c‐Si solar cells
Authors: Ortega P. , Orpella A. , Martín I. , Colina M. , López G. , Voz C. , Sánchez M. I. , Molpeceres C. , Alcubilla R.
Published: April 2011

In this work we study the optimization of laser‐fired contact (LFC) processing parameters, namely laser power and number of pulses, based on the electrical resistance measurement of an aluminum single LFC point. LFC process has been made through four passivation layers that are typically used in c‐Si and mc‐Si solar cell fabrication: thermally grown silicon oxide (SiO2), deposited phosphorus‐doped amorphous silicon carbide (a‐SiCx/H(n)), aluminum oxide (Al2O3) and silicon nitride (SiNx/H) films. Values for the LFC resistance normalized by the laser spot area in the range of 0.65–3 mΩ cm2 have been obtained. Copyright © 2011 John Wiley & Sons, Ltd.
Structure and function of the symbiosis partners of the lung lichen (Lobaria pulmonariaL. Hoffm.) analyzed by metaproteomics
Authors: Schneider Thomas , Schmid Emanuel , de Castro João V. , Cardinale Massimiliano , Eberl Leo , Grube Martin , Berg Gabriele , Riedel Kathrin
Published: April 2011

Environmental proteomics, also referred to as metaproteomics, is an emerging technology to study the structure and function of microbial communities. Here, we applied semi‐quantitative label‐free proteomics using one‐dimensional gel electrophoresis combined with LC‐MS/MS and normalized spectral counting together with fluorescence in situ hybridization and confocal laser scanning microscopy to characterize the metaproteome of the lung lichen symbiosisLobaria pulmonaria. In addition to the myco‐ and photobiont,L. pulmonariaharbors proteins from a highly diverse prokaryotic community, which is dominated byProteobacteriaand including alsoArchaea. While fungal proteins are most dominant (75.4% of all assigned spectra), about the same amount of spectra were assigned to prokaryotic proteins (10%) and to the green algal photobiont (9%). While the latter proteins were found to be mainly associated with energy and carbohydrate metabolism, a major proportion of fungal and bacterial proteins appeared to be involved in PTMs and protein turnover and other diverse functions.
Rapid isolation and characterization of bacterial lipopeptides using liquid chromatography and mass spectrometry analysis
Authors: Kwok Yan , Sung Wang‐Chou , Lin Annie Li‐Hsiu , Liu Hsueh‐Hung , Chou Frieda Ai‐Hsiang , Hsieh Steve Shih‐Yang , Leng Chih‐Hsiang , Chong Pele
Published: April 2011

The structural analysis of post‐translational modifications (PTMs) of lipoproteins is difficult due to the hydrophobic properties of their fatty acid moieties. At the present time, the relative positions of fatty acid components on the N‐acyl‐S‐diacylglycerylcysteine core structure has not been specifically identified in any natural or bacterial expressed recombinant lipoproteins. In this study, we describe a rapid solid‐phase extraction using acetonitrile and isopropanol method that can be performed manually to isolate large amounts of relatively pure lipopeptides generated by the limited tryptic‐digestion of recombinant lipoproteins. Using these lipopeptides and LC/MS mass spectra analysis, two groups of N‐terminal lipidated (diacyl or triacyl) molecules that differ by one fatty acid unit were successfully identified. This LC/MS method also provided the separation of lipopeptides differing by 14 Da for the on‐line MS identification. Multiple‐stage fragmentation analyses of the di‐ and triacyl lipopeptides using both the positive and negative ion modes enabled to identify the putative structure of the N‐acyl‐S‐diacylglycerylcysteine containing an amide bond to palmitic acid at the N‐terminal cysteine, a palmitic acid at sn1 position, and an unsaturated fatty acid of either hexadecenoic acid, cyclopropaneoctanoic acid, oleic acid and nonadecenoic acid at sn2 position of diacylglycerol residue through ester bonding. For diacyl lipoprotein, the saturated palmitoyl fatty acid group is absent at sn1 position of glycerol‐derived lipid residue of lipopeptide.
How to prevent process accidents
Authors: Louvar J.F.
Published: April 2011

Most professionals agree that the correct application of process safety management (OSHA's Process Safety Management regulation) will prevent major process accidents. Some professionals also agree that the PSM documentation is not enough; a good PSM program must include good communication, delegation, and follow‐up. There are also some who emphasize that operational discipline is an essential element of the PSM program. In all cases, however, the teachings do not say how to obtain the desired results. Even when discipline is discussed, the discussions do not specify how this discipline is achieved. Many articles additionally emphasize the importance of having a good safety culture—but they do not say how to achieve it.

In general, current articles do not explicitly teach how to develop the necessary PSM program, the discipline, and the culture—to prevent major process accidents. These articles very appropriately stress what needs to be done to prevent major accidents; however, they do not tell you how this is accomplished. This specific article is designed to be a companion article to the cited articles; together they show what is required and how to achieve the desired results to prevent process accidents. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2011.
The structural transition behavior of CdSe/ZnS core/shell quantum dots under high pressure
Authors: Li Zepeng , Wang Lin , Liu Bingbing , Wang Jinhua , Liu Bo , Li Quanjun , Zou Bo , Cui Tian , Meng Yue , Mao Ho‐kwang , Liu Zhenxian , Liu Jing
Published: April 2011

The structural phase transition of CdSe/ZnS core/shell quantum dots (QDs) has been studied by in situ angle‐dispersive X‐ray diffraction under high pressure up to 53.6 GPa. The CdSe core transforms from wurtzite to rock‐salt structure near 6.3 GPa and then to Cmcm or distorted Cmcm structure probably occurs at 45.1 GPa which has not been observed in CdSe nanomaterials before. The critical pressure from wurtzite to rock‐salt and the bulk modulus of rock‐salt phase are much higher than those for bulky and uncapped nanoparticle CdSe. The released sample can be kept in rock‐salt phase for a certain time, verified by photoluminescence (PL) spectra, quite different from the reversible transition for pure CdSe. A reasonable interpretation of the experimental phenomena is given by comparing the bulk modulus of the core and shell and studying the stress sate of the core after decompression. Our study suggests that capping a hard shell is an effective approach to quench the high pressure phase of nanomaterial with a reversible phase transition.
The influence of observations propagated by convectively coupled equatorial waves
Authors: Moteki Qoosaku , Yoneyama Kunio , Shirooka Ryuichi , Kubota Hisayuki , Yasunaga Kazuaki , Suzuki Junko , Seiki Ayako , Sato Naoki , Enomoto Takeshi , Miyoshi Takemasa , Yamane Shozo
Published: April 2011

This paper describes the propagation of the influence of radiosonde observations made during MISMO (Mirai Indian Ocean cruise for the Study of the Madden–Julian oscillation‐convection Onset), which was conducted over the Indian Ocean in the boreal autumn of 2006. The impact of these observations was assessed using an experimental reanalysis called ‘ALERA’ that was produced by the local ensemble transform Kalman filter with the atmospheric global circulation model for the Earth Simulator. The difference of the analysis ensemble mean between the analysis cycles with and without the MISMO observations was used to quantify the influence of these observations on the analysis field, which we call impact signals. Since the impact signals were contaminated by noise, probably due to the model's truncated spectral basis, a significance test was performed using the analysis ensemble spread, and the numerical noise was then successfully eliminated. The results indicated that convectively coupled equatorial waves propagated the impact signals to the central Pacific to the east and to the African continent to the west. In particular, the analysis fields around typhoons Cimaron, Chebi, and Durian over the tropical Western Pacific were significantly modified by the propagation of the impact signals through the Kelvin waves. Here two factors played important roles: (1) the meridional positions of the typhoons; and (2) the duration of the observations. The equatorial Rossby waves also made a significant contribution to the propagation of the impact signals. Such influences through the waves resulted in the reduction of the analysis spread. The shape of the region of reduced spread resembled the Matsuno–Gill pattern with an east‐west width of more than 20000 km. Copyright © 2011 Royal Meteorological Society
Layers of insect echoes near a thunderstorm and implications for the interpretation of radar data in terms of airflow
Authors: Browning K. A. , Nicol J. C. , Marsham J. H. , Rogberg P. , Norton E. G.
Published: April 2011

Insects can serve as useful radar targets for determining aspects of the structure and kinematics of the atmosphere, but it is necessary sometimes to know more about insect behaviour in order to have confidence in the meteorological interpretations. A variety of meteorological radars situated at Chilbolton in southern England have been used to investigate the nature of multiple shallow clear‐air echo layers that were detected at heights between 1.0 and 2.5 km in the vicinity of an elevated daytime thunderstorm (mesoscale convective system). Multi‐wavelength and polarization measurements were used to confirm that the layers were due in large part to insects. The layers were within potentially warm air near the top of a cold undercurrent of surface air. The convective updraught of the thunderstorm was fed by air from just above the cold undercurrent. Some of the insect layers were within air destined to ascend into the storm's convective updraught and some were within undercurrent air that was forced to ascend only temporarily as the storm approached. Initially the layer echoes ascended with the airflow but then, close to the storm, their intensity weakened despite continuing updraughts, mainly as a result of the insects dropping downwards. Far ahead of the storm the insects showed a strong preference to remain within their individual shallow layers but, even close to the storm, where they started dropping out, insects still retained a preference to be within these layers. As a result, some layers continued to be discernible as they followed the ascending airflow towards the storm, thereby continuing to serve as useful meteorological tracers of the perturbed flow in the vicinity of the thunderstorm. Copyright © 2011 Royal Meteorological Society
Anatomy of an observed African easterly wave in July 2006
Authors: Bain C. L. , Parker D. J. , Dixon N. , Fink A. H. , Taylor C. M. , Brooks B. , Milton S. F.
Published: April 2011

The detailed structure of an African easterly wave (AEW) observed during the AMMA field campaign is analysed. The wave was present from 25 to 29 July 2006. A complex circulation pattern was observed: the overall structure of convection and the positive vorticity of the trough region had an elongated inverted‐V appearance, wrapped around an area of low winds and clear skies. Satellite imagery showed that the AEW was a significant influence on the modulation of convection on the large scale.

The wave was identified initially through its strong signature on soil moisture and convection. The AEW structure observed was not anticipated and has not been discussed in previous literature. In addition, wave tracking using a Hovmöller diagram of meridional winds did not detect the wave, and a Hovmöller of vorticity showed the wave moved at a slower speed than other AEWs in July.

New schematics explaining the structure are presented, describing the case as observed by satellites and analysed by a limited‐area version of the Met Office Unified Model. It is proposed that the positive vorticity branches of the inverted‐V can be regarded as analogous to atmospheric fronts, with characteristic gradients in winds and thermodynamic properties, acting as locations for enhanced convection. The implications of the new case are discussed in relation to previous theory and it is suggested that the accepted model of an idealised AEW is incomplete and should be extended to include more complex structures. Copyright © 2011 Royal Meteorological Society and British Crown Copyright, the Met Office