bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of well and groove microchannel bioreactors for cell culture
Authors: Korin Natanel , Bransky Avishay , Khoury Maria , Dinnar Uri , Levenberg Shulamit
Published: September 2008

Microfluidic bioreactors have been shown valuable for various cellular applications. The use of micro‐wells/grooves bioreactors, in which micro‐topographical features are used to protect sensitive cells from the detrimental effects of fluidic shear stress, is a promising approach to culture sensitive cells in these perfusion microsystems. However, such devices exhibit substantially different fluid dynamics and mass transport characteristics compared to conventional planar microchannel reactors. In order to properly design and optimize these systems, fluid and mass transport issues playing a key role in microscale bioreactors should be adequately addressed. The present work is a parametric study of micro‐groove/micro‐well microchannel bioreactors. Operation conditions and design parameters were theoretically examined via a numerical model. The complex flow pattern obtained at grooves of various depths was studied and the shear protection factor compared to planar microchannels was evaluated. 3D flow simulations were preformed in order to examine the shear protection factor in micro‐wells, which were found to have similar attributes as the grooves. The oxygen mass transport problem, which is coupled to the fluid mechanics problem, was solved for various groove geometries and for several cell types, assuming a defined shear stress limitation. It is shown that by optimizing the groove depth, the groove bioreactor may be used to effectively maximize the number of cells cultured within it or to minimize the oxygen gradient existing in such devices. Moreover, for sensitive cells having a high oxygen demand (e.g., hepatocytes) or low endurance to shear (e.g., human embryonic stem cells), results show that the use of grooves is an enabling technology, since under the same physical conditions the cells cannot be cultured for long periods of time in a planar microchannel. In addition to the theoretical model findings, the culture of human foreskin fibroblasts in groove (30 µm depth) and well bioreactors (35 µm depth) was experimentally examined at various flow rates of medium perfusion and compared to cell culture in regular flat microchannels. It was shown that the wells and the grooves enable a one order of magnitude increase in the maximum perfusion rate compared to planar microchannels. Altogether, the study demonstrates that the proper design and use of microgroove/well bioreactors may be highly beneficial for cell culture assays. Biotechnol. Bioeng. 2009;102: 1222–1230. © 2008 Wiley Periodicals, Inc.
The phytochemical analysis and antioxidant activity assessment of orange peel (Citrus sinensis) cultivated in Greece–Crete indicates a new commercial source of hesperidin
Authors: Kanaze Firas I. , Termentzi Aikaterini , Gabrieli Chrysi , Niopas Ioannis , Georgarakis Manolis , Kokkalou Eugene
Published: September 2008

The flavonoid content of several methanolic extract fractions of Navel orange peel (flavedo and albedo of Citrus sinensis) cultivated in Crete (Greece) was first analysed phytochemically and then assessed for its antioxidant activity in vitro. The chemical structures of the constituents fractionated were originally determined by comparing their retention times and the obtained UV spectral data with the available bibliographic data and further verified by detailed LC‐DAD‐MS (ESI+) analysis. The main flavonoid groups found within the fractions examined were polymethoxylated flavones, O‐glycosylated flavones, C‐glycosylated flavones, O‐glycosylated flavonols, O‐glycosylated flavanones and phenolic acids along with their ester derivatives. In addition, the quantitative HPLC analysis confirmed that hesperidin is the major flavonoid glycoside found in the orange peel. Interestingly enough, its quantity at 48 mg/g of dry peel permits the commercial use of orange peel as a source for the production of hesperidin. The antioxidant activity of the orange peel methanolic extract fractions was evaluated by applying two complementary methodologies, DPPH• assay and the Co(II)/EDTA‐induced luminol chemiluminescence approach. Overall, the results have shown that orange peel methanolic extracts possess moderate antioxidant activity as compared with the activity seen in tests where the corresponding aglycones, diosmetin and hesperetin were assessed in different ratios. Copyright © 2008 John Wiley & Sons, Ltd.
An isocratic fluorescence HPLC assay for the monitoring of l‐asparaginase activity and l‐asparagine depletion in children receiving E. colil‐asparaginase for the treatment of acute lymphoblastic leukaemia
Authors: Nath Christa E. , Dallapozza Luciano , Eslick Adam E. , Misra Ashish , Carr Deborah , Earl John W.
Published: September 2008

A novel assay for the determination of l‐asparaginase activity in human plasma is described that is based on the HPLC quantitation of l‐aspartic acid produced during enzyme incubation. Methods for monitoring l‐asparagine depletion are also described. Chromatography of l‐aspartic acid, l‐asparagine and l‐homoserine (the internal standard) involved derivatization with o‐pthaldialdehyde, then separation from other amino acids on a Phenomenex Luna C18 column using a 1 mL/min flow rate and a mobile phase consisting of di‐potassium hydrogen orthophosphate propionate buffer, pH 6, with 10% methanol and 10% acetonitrile. Fluoresence detection was at excitation/emission wavelengths of 357/455 nm. Under these conditions l‐aspartic acid, l‐asparagine and l‐homoserine had retention times of 3.5, 9.8 and 17.7 min, respectively. The l‐asparaginase assay was linear from 0.1 to 10 U/mL activity and interday precision and accuracy were less than 13%. The limit of quantitation was approximately 0.03 U/mL. The assay utility was established in 12 children who received E. coli l‐asparaginase as treatment for acute lymphoblastic leukaemia. Copyright © 2008 John Wiley & Sons, Ltd.
Predictive Model of Hydrogen Sulfide Absorption by Chelate Solution in a Venturi Scrubber
Authors: Ahari J. S. , Forsat K. , Djenab M. H. , Mohammadbigy K. , Vahidi M. , Shafiei Z.
Published: September 2008

In the present study, a simple model was used to predict the removal efficiency of a venturi scrubber for H2S absorption into a ferric chelate solution. From momentum and mass balances in the scrubber, a set of first‐order, nonlinear ordinary differential equations relating predominantly the liquid velocity with the H2S concentration in the liquid along the axial direction in the scrubber were formulated. These relationships were numerically solved to give performance profiles. The validity of the model was examined by comparing the results of the model with experimental data from the working laboratory scale. The results predicted from the model are in good agreement with the experimental data obtained in different sizes of the venturi scrubber and operating variables.
Preparation and Characterization of Codeposited Palladium‐Nickel/Titanium Electrodes and Palladium‐Nickel/Polymeric Pyrrole Film/Titanium Electrodes
Authors: Hu X. , Ge H. , Li B.‐H. , Sun Z.‐R.
Published: September 2008

Palladium‐nickel/titanium (Pd‐Ni/Ti) and palladium‐nickel/polymeric pyrrole film/titanium (Pd‐Ni/PPy/Ti) electrodes were prepared by electrochemical deposition. The electrochemical characteristics of the Pd‐Ni/Ti and Pd‐Ni/PPy/Ti electrodes were studied by means of cyclic voltammetry (CV) based on orthogonal experiments. CV studies on the electrodes were conducted in 0.5 mol/L sulfuric acid solution. Experimental results indicate that the hydrogen adsorption peak value of the Pd‐Ni/PPy/Ti electrode seen at ca. –500 mV is larger than that of Pd‐Ni/Ti electrode. Scanning electron microscope (SEM) images indicate that polymeric pyrrole film, which formed on electrode can modify the electrode surface configuration significantly and provide the surface of the Pd‐Ni/PPy/Ti electrode with more layers and a larger surface area.
Simulation Study of a Novel Process Co‐Producing Synthesis Gas and Light Olefins
Authors: Wang S.‐F. , Zhao Y.‐H. , Wen H. , Xu Z.‐H.
Published: September 2008

There are abundant resources of heavy hydrocarbons worldwide, and their utilization is becoming more widespread as time progresses. The present paper proposes a process that combines coke gasification and heavy hydrocarbon pyrolysis, producing synthesis gas and light olefins. Simulation studies on the process are carried out by using Aspen Plus. The results show that the temperature of the gasification‐pyrolysis can be controlled by changing the feed rate of O2 and steam. In addition, the coke jam problem can be solved by increasing the gasification‐pyrolysis temperature or residence time. The maximum amount of light olefins can be acquired by controlling the gasification‐pyrolysis residence time. More than 37 wt % heavy hydrocarbons are changed to synthesis gas with more than 15 wt % changed to light olefins in the case studied.
An Adaptive Control Concept for Simulated Moving Bed Plants in Case of Complete Separation
Authors: Fütterer M.
Published: September 2008

Simulated Moving Bed (SMB) technology has played an important role in the separation of binary mixtures. An exact adjustment of the volumetric flow rates is necessary for trouble‐free operation. In this contribution, an adaptive control concept is introduced that determines the necessary control variables for complete automatic separation. A simple model is derived for the movement of the concentration fronts and a controller is developed based on the model. The simulation result shows the potential of applying such a control design for application in industrial use.
DMAP as an Effective Catalyst To Accelerate the Solubilization of Waste Fiber‐Reinforced Plastics
Authors: Kamimura Akio , Yamada Kazuo , Kuratani Tomohiro , Oishi Yusuke , Watanabe Takeru , Yoshida Takayuki , Tomonaga Fumiaki
Published: September 2008

Waste fiber‐reinforced plastics (FRPs), which are formidable composite plastics for chemical treatment, can be efficiently depolymerized by treatment with supercritical methanol in the presence of catalytic amounts of 4‐(dimethylamino)pyridine (DMAP), which is a well‐known catalyst for the formation of esters and amides. This novel depolymerization reaction also provides ready separation of the depolymerized products into three components: methanol‐soluble oil, CHCl3‐soluble solid, and an inorganic residue. Thus, almost complete decomposition of FRP as well as useful separation of the decomposed products was achieved with the present method, and the latter were ready for chemical recycling. Investigation of the reaction profile revealed that the reaction rate increased as the amount of DMAP increased. Unfortunately, DMAP employed in the reaction could not be recovered because of its decomposition catalyzed by dimethyl phthalate, a depolymerized product from waste FRP, under the reaction conditions employed.
Immunoprevalence of the CD4+ T‐cell response to HIV Tat and Vpr proteins is provided by clustered and disperse epitopes, respectively
Authors: Castelli Florence A. , Houitte Diane , Munier Gaetan , Szely Natacha , Lecoq Alain , Briand Jean‐Paul , Muller Sylviane , Maillere Bernard
Published: September 2008

Recent studies have suggested including nonstructural proteins as Tat and Vpr in HIV vaccines. However, little is known about the CD4+ T‐cell response that these small proteins induce in humans. We have therefore evaluated these responses by in vitro priming experiments of CD4+ T lymphocytes harvested in healthy donors. In the Tat protein, only one peptide primed CD4+ T cells of eight HLA unrelated healthy donors. T cells induced by this peptide recognized immature DC loaded with the native Tat protein and are restricted by multiple HLA‐DR molecules, in agreement with its binding capacity. This peptide was therefore processed in an appropriate manner and was highly immunoprevalent. CD4+ T‐cell response to Vpr peptides was more disperse and involved six different peptides depending on the HLA‐DR molecules of the donors. Two overlapping peptides were T‐cell stimulating in at least half of the donors. T‐cell response to Vpr in multiple donors is the result of a combination of several CD4+ T‐cell epitopes with good to moderate immunoprevalence. Altogether, our results show that the frequency of responders to HIV Tat or Vpr proteins relies on one or multiple CD4+ T‐cell epitopes, respectively.
Microwave‐Assisted Stereoselective One‐Pot Synthesis of Symmetrical and Unsymmetrical 2,5‐Diketopiperazines from Unprotected Amino Acids
Authors: Jainta Manuel , Nieger Martin , Bräse Stefan
Published: September 2008

The facile condensation of unprotected amino acids by a phosphite‐promoted one‐step coupling reaction is a highly efficient synthesis to generate stereoselective and optically pure symmetrical and unsymmetrical functionalized diketopiperazines. The use of microwaves enhanced by small amounts of ionic liquid is accompanied by significant improvement in reaction times and yields. Simple filtration through a pad of silica provides the pure compounds in very good to excellent yields.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Directed (R)‐ or (S)‐Selective Dynamic Kinetic Enzymatic Hydrolysis of 1,2,3,4‐Tetrahydroisoquinoline‐1‐carboxylic Esters
Authors: Paál Tihamér A. , Liljeblad Arto , Kanerva Liisa T. , Forró Enikő , Fülöp Ferenc
Published: September 2008

The first synthesis of both enantiomers of 6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline‐1‐carboxylic acid was accomplished through dynamic kinetic resolution in procedures based on CAL‐B‐ or subtilisin Carlsberg‐catalysed enantioselective hydrolysis of the corresponding ethyl esters in aqueous NH4OAc buffer at pH 8.5. The products were obtained with high enantiopurity (92–93 % ee) in good yields (85–92 %). (R)‐1,2,3,4‐Tetrahydroisoquinoline‐1‐carboxylic acid was obtained with high enantiopurity (98 % ee) and in good yield (85 %) in a CAL‐B‐catalysed process, under similar conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Odour and flavour thresholds for key aroma components in an orange juice matrix: esters and miscellaneous compounds
Authors: Plotto Anne , Margaría Carlos A. , Goodner Kevin L. , Baldwin Elizabeth A.
Published: September 2008

Thresholds for flavour volatiles have been traditionally calculated in water or air but they may vary widely in more complex matrices such as milk, gels or fruit slurries. The data presented are part of a continuing study to provide the industry with threshold guidelines more adequate for the use of flavours in citrus juices. Thresholds of aroma compounds of orange juice (OJ) were determined in reconstituted pump‐out (RPO), approaching a deodorized OJ matrix and served at 10–12 °C, the temperature at which OJ is consumed. The three‐alternative forced choice (3‐AFC) method was used (ASTM: E‐679). Sixteen to twenty panelists were presented with RPO samples arranged in five rows of three samples corresponding to five spiking levels, each separated by a factor of 3, with a 3‐AFC presentation at each level. For each compound, the test was repeated four times. Compounds tested were verified for purity by GC–MS and GC–O. Orthonasal and retronasal thresholds for esters were twice (methyl butanoate) to 30 times (ethyl propanoate) higher in the orange juice matrix than published values in water. The odour activity values (OAVs) of volatile compounds were calculated for two OJs; nine compounds had an orthonasal OAV < 1 when using thresholds determined in RPO, while in contrast, these compounds had an OAV > 1 when calculated with published thresholds determined in water. The relative OAV of some compounds had changed with respect to each other, indicating a different contribution of these compounds to OJ flavour when their OAV was calculated in RPO. These results show the importance of non‐water‐soluble compounds on odour and flavour perception. The threshold values provided herein are directly usable by the industry, in comparison with the current values published in water, and will help in developing models that would explain OJ flavour based on interactions with the matrix. Copyright © 2008 John Wiley & Sons, Ltd.
Strongly coupled simulation of fluid–structure interaction in a Francis hydroturbine
Authors: Wang W. Q. , He X. Q. , Zhang L. X. , Liew K. M. , Guo Y.
Published: September 2008

This work simulates a complex fluid flow in fluid–structure interaction (FSI). The flow under consideration is governed by Navier–Stokes equations for incompressible viscous fluids and modeled with the finite volume method. Large eddy simulation is used to simulate the unsteady turbulent flow. The structure is represented by a finite element formulation. The present work introduces a strongly coupled partitioned approach that is applied to complex flow in fluid machinery. In this approach, the fluid and structure equations are solved separately using different solvers, but are implicitly coupled into one single module based on sensitivity analysis of the important displacement and stress modes. The applied modes and their responses are used to build up a reduced‐order model. The proposed model is used to predict the unsteady flow fields of a 3D complete passage, involving in stay, guide vanes, and runner blades, for a Francis hydro turbine and FSI is considered. The computational results show that a fairly good convergence solution is achieved by using the reduced‐order model that is based on only a few displacement and stress modes, which largely reduces the computational cost, compared with traditional approaches. At the same time, a comparison of the numerical results of the model with available experimental data validates the methodology and assesses its accuracy. Copyright © 2008 John Wiley & Sons, Ltd.
Microarray‐based genomic profiling reveals novel genomic aberrations in follicular lymphoma which associate with patient survival and gene expression status
Authors: Schwaenen Carsten , Viardot Andreas , Berger Hilmar , Barth Thomas F. E. , Bentink Stefan , Döhner Hartmut , Enz Martina , Feller Alfred C. , Hansmann Martin‐Leo , Hummel Michael , Kestler Hans A. , Klapper Wolfram , Kreuz Markus , Lenze Dido , Loeffler Markus , Möller Peter , Müller‐Hermelink Hans‐Konrad , Ott German , Rosolowski Maciej , Rosenwald Andreas , Ruf Sandra , Siebert Reiner , Spang Rainer , Stein Harald , Truemper Lorenz , Lichter Peter , Bentz Martin , Wessendorf Swen
Published: September 2008

Follicular lymphoma (FL) is characterized by a large number of chromosomal aberrations. However, their exact genomic extension and involved target genes remain to be determined. For this purpose, we used array‐based intermediate‐high resolution genomic profiling in combination with Affymetrix™ gene expression analysis. Tumor specimens from 128 FL patients were analyzed for the presence of genomic aberrations and the results were correlated to clinical data sets and mRNA expression levels. In 114 (89%) of the 128 analyzed cases, a total of 688 genomic aberrations (384 gains/amplifications and 304 losses) were detected. Frequent genomic aberrations were: −1p36 (18%), +2p15 (24%), −3q (14%), −6q (25%), +7p (19%), +7q (23%), +8q (14%), −9p (16%), −11q (15%), +12q (20%), −13q (11%), −17p (16%), +18p (18%), and +18q (28%). Critical segments of these imbalances were delineated to genomic fragments with a minimum size down to 0.2 Mb. By comparison of these with mRNA gene expression data, putative candidate genes were identified. Moreover, we found that deletions affecting the tumor suppressor gene CDKN2A/B on 9p21 were detected in nontransformed FL grade I–II. For this aberration as well as for −6q25 and −6q26, an association with inferior survival was observed. © 2008 Wiley‐Liss, Inc.
HIF‐1α and HIF‐2α have divergent roles in colon cancer
Authors: Imamura Takaaki , Kikuchi Hirotoshi , Herraiz Maria‐Teresa , Park Do‐Youn , Mizukami Yusuke , Mino‐Kenduson Mari , Lynch Maureen P. , Rueda Bo R. , Benita Yair , Xavier Ramnik J. , Chung Daniel C.
Published: September 2008

Hypoxia‐inducible factor (HIF)‐1 and HIF‐2 are heterodimeric transcription factors that mediate the cellular response to hypoxia. Their key regulatory subunits, HIF‐1α and HIF‐2α, are induced similarly by hypoxia, but their functional roles in cancer may be distinct and isoform‐specific. SW480 colon cancer cells with stable expression of siRNA to HIF‐1α or HIF‐2α or both were established. HIF‐1α‐deficient cells displayed lower rates of proliferation and migration, but HIF‐2α‐deficient cells exhibited enhanced anchorage independent growth in a soft agar assay. Xenograft studies revealed that HIF‐1α deficiency inhibited overall tumor growth, whereas deficiency of HIF‐2α stimulated tumor growth. In human colon cancer tissues, expression of HIF‐1α and to a lesser extent, HIF‐2α, was linked to upregulation of VEGF and tumor angiogenesis. However, loss of expression of HIF‐2α but not HIF‐1α was strongly correlated with advanced tumor stage. DNA microarray analysis identified distinct sets of HIF‐1α and HIF‐2α target genes that may explain these phenotypic differences. Collectively, these findings suggest that HIF isoforms may have differing cellular functions in colon cancer. In particular, HIF‐1α promoted the growth of SW480 colon cancer cells but HIF‐2α appeared to restrain growth. Consequently, therapeutic approaches that target HIF may need to consider these isoform‐specific properties. © 2008 Wiley‐Liss, Inc.
Dietary patterns and risk of cancer: A factor analysis in Uruguay
Authors: De Stefani Eduardo , Deneo‐Pellegrini Hugo , Boffetta Paolo , Ronco Alvaro L. , Aune Dagfinn , Acosta Gisele , Mendilaharsu María , Brennan Paul , Ferro Gilles
Published: September 2008

A multisite case–control study on factor analysis and several cancer sites (mouth and pharynx, esophagus, stomach, colon, rectum, larynx, lung, breast, prostate, bladder, kidney) was conducted in Uruguay. The study included 3,528 cases and 2,532 controls. Factor analysis (principal components) was modeled among controls. This patterning method retained 4 factors per sex, labeled as prudent, drinker, traditional and Western. Odds ratios for these cancer sites, stratified by sex, were estimated using polytomous regression. Whereas the prudent pattern was mainly negatively associated with cancers of the upper aerodigestive tract, the Western pattern showed a strong increase in breast, lung and colon cancers. The study allowed for the reproducibility of the prudent, drinker and Western patterns, whereas the traditional pattern appears to be country specific. © 2008 Wiley‐Liss, Inc.
A novel cell‐free screen identifies a potent inhibitor of the Fanconi anemia pathway
Authors: Landais Igor , Sobeck Alexandra , Stone Stacie , LaChapelle Alexis , Hoatlin Maureen E.
Published: September 2008

The Fanconi Anemia (FA) DNA damage response pathway is involved in the processing of DNA interstrand crosslinks (ICLs). As such, inhibition of the FA pathway could chemosensitize FA‐competent tumor cells to commonly used ICL agents like cisplatin. Moreover, suppression of the FA pathway is synthetic lethal with deficiencies in several other DNA repair pathways, suggesting that FA pathway inhibitors could be used in targeted therapies against specific tumors. To identify such inhibitors, we designed a novelin vitroscreening assay utilizingXenopusegg extracts. Using the DNA‐stimulated monoubiquitylation ofXenopusFANCD2 (xFANCD2‐L) as readout, a chemical library screen identified DDN (2,3‐dichloro‐5,8‐dihydroxy‐1,4‐naphthoquinone) as a novel and potent FA pathway inhibitor. DDN inhibited xFANCD2‐L formation in a dose‐dependent manner in both extracts and human cells without disruption of the upstream FA core complex. DDN also inhibited the characteristic subnuclear FANCD2 foci formation following DNA damage. Moreover, DDN displayed a greater synergistic effect with cisplatin in a FA‐proficient cancer cell line compared to its FA‐deficient isogenic counterpart, suggesting that DDN might be a good lead candidate as cisplatin chemosensitizer in both FA‐deficient and FA‐competent tumors. This system constitutes the first cell‐free screening assay for identifying compounds that inhibit the FA pathway and provides a new biochemical platform for mapping the functions of its various components with specific chemical inhibitors. © 2008 Wiley‐Liss, Inc.
Black carbon in wildfire‐affected shrubland Mediterranean soils
Authors: Rovira Pere , Duguy Beatriz , Ramón Vallejo V.
Published: September 2008

Because Mediterranean ecosystems are prone to fire, their soils are expected to contain relevant amounts of black carbon (BC); nevertheless, quantitative information is scarce. Herein, we provide data on the abundance of BC in the surface soil (uppermost 5 cm) of shrubland plots on old agricultural fields diversely affected by fires (0, 1, or 2 wildfires in the last 25 y) and with contrasted land‐use histories (either never cropped, early abandoned, or recently abandoned). Black C and black nitrogen (BN) were quantified in the surface horizon (0–5 cm) as the residue of low‐temperature dichromate oxidation, after previous destruction of mineral matter with HF. The obtained amounts of BC ranged from 0.73 to 10.32 g (kg dw)–1 (mean: 3.07, which corresponds to an average of 8.62% of the total organic C), while the amounts of BN ranged from 21.5 to 373.0 mg (kg dw)–1 (mean: 97.1, or an average of 4.30% of the total N of the samples). Repeated fires did not consistently increase either the BC or the BN amounts. Black‐C and (especially) BN accumulation seems related to fine silt, whereas the effect of clay is unclear. Even though the amounts of BC obtained in this study are slightly higher than those from other ecosystems, including Mediterranean broad‐leaved forests, overall they are far from the very high values reported in the literature for chernozems from Germany or Canada. Thus, on the whole, in Mediterranean shrublands affected by wildfires, BC does not seem to be a dominant fraction in the soil organic C.
Medium‐term effects of poultry manure on pine nitrogen uptake in a 15N‐labeled burnt soil§
Authors: Castro Arturo , González‐Prieto Serafín J. , Carballas Tarsy
Published: September 2008

The effects of poultry manure (PM), used for the reclamation of a 15N‐labeled burnt soil, on N nutrition of pine seedlings were evaluated during one year in a pot experiment. Six treatments were used: 15N‐labeled soil (LS), 15N‐labeled burnt soil (BLS), and BLS+PM at doses equivalent to 1, 2, 4, and 8 t ha–1 of dry PM (PM1, PM2, PM4, and PM8, respectively). Either in the whole tree or the different organs, N concentration: (1) decreased (p 0.05) in the order LS > BLS, BLS+PM1, BLS+PM2, BLS+PM4 > BLS+PM8 and (2) was negatively correlated with phytomass production (p < 0.05 to p < 0.01). The two highest amounts of assimilated N per kg dry soil were found in LS and BLS (130–134 mg) and the lowest in BLS+PM8 (87 mg), the other treatments being in an intermediate range (108–115 mg). Irrespective of the soil treatment, 56%–66% of the pine‐N were accounted for by needles, 29%–32% by roots, and 8%–12% by stems, the differences among organs being always significant (p < 0.05). The percentage of pine‐N derived from PM (%PNDFM) increased steadily with PM dose, from 1.7% in BLS+PM1 to 13.3% in BLS+PM8, reaching values for the two highest PM doses within the range found for 15N mineral fertilizers in forests. From 8.2% to 16.9% of the PM‐N was assimilated by the pines. Although differences among treatments were not significant, the two highest values were found in BLS+PM4 and BLS+PM8. Therefore, the 15N data showed clearly that there is a positive medium‐term effect of PM on pine N nutrition during the reafforestation phase of burnt‐forest reclamation. The lower total N uptake by pine seedlings in the PM treatments was explained in terms of lower levels of soil available N due to its exportation with the phytomass of the preceding ryegrass culture, used for the early protection phase in the burnt soil–reclamation procedure.
A single drought event of 100‐year recurrence enhances subsequent carbon uptake and changes carbon allocation in experimental grassland communities
Authors: Mirzaei Heydar , Kreyling Juergen , Zaman Hussain Mir , Li Yuelin , Tenhunen John , Beierkuhnlein Carl , Jentsch Anke
Published: September 2008

Evidence suggests that the expected increase in frequency and magnitude of extreme weather events during climate change will alter plant productivity. Therefore, extreme weather events might also be capable of changing C sequestration and allocation. Here, experimental grassland communities of two species compositions, differing in their diversity, were exposed either to a simulated single drought or to a heavy‐rainfall event. The magnitude of these manipulations imitated the local 100‐year weather extreme according to extreme‐value statistics. Effects on Net Ecosystem CO2 Exchange (NEE in µmol m–2 s–1) as well as aboveground biomass production and leaf‐area index (LAI) were recorded from prior to the manipulations until two months after the manipulations ended. Initial light utilization efficiency and maximum NEE increased after the drought. No change in the respiration was detected and maximum uptake capacity (GPPmax) was 15% higher for the drought‐manipulated plots compared to controls, which indicates an enhanced CO2 uptake into the systems. The level of diversity was also found to alter the light‐response curves, increasing respiration and maximum NEE to a higher degree than drought in the more diverse compared to the less diverse community. This resulted in an increase of GPPmax by 55%. No significant interactions between species composition and weather manipulations were detected. Interestingly, aboveground biomass production was not significantly affected by weather manipulations, even though LAI increased due to drought. This increase was caused by a decrease in the ratio between reproductive and vegetative growth. The heavy‐rainfall manipulation resulted in no significant effects. Our data suggest that C sequestration can be enhanced by a single weather event. However the importance, long‐term duration, and thresholds or turning points of such effects need to be investigated further as intensification of weather extremes is currently emerging as one of the most important facets of climate change.
The use of lysimeter data for the test of two soil–water balance models: A case study
Authors: Wegehenkel Martin , Zhang Yongqian , Zenker Thomas , Diestel Heiko
Published: September 2008

Two soil–water balance models were tested by a comparison of simulated with measured daily rates of actual evapotranspiration, soil water storage, groundwater recharge, and capillary rise. These rates were obtained from twelve weighable lysimeters with three different soils and two different lower boundary conditions for the time period from January 1, 1996 to December 31, 1998. In that period, grass vegetation was grown on all lysimeters. These lysimeters are located in Berlin‐Dahlem, Germany. One model calculated the soil water balance using the Richards equation. The other one used a capacitance approach. Both models used the same modified Penman formula for the estimation of potential evapotranspiration and the same simple empirical vegetation model for the calculation of transpiration, interception, and evaporation. The comparisons of simulated with measured model outputs were analyzed using the modeling‐efficiency index IA and the root mean squared error RMSE. At some lysimeters, the uncalibrated application of both models led to an underestimation of cumulative and annual rates of groundwater recharge and capillary rise, despite a good simulation quality in terms of IA and RMSE. A calibration of soil‐hydraulic and vegetation parameters such as maximum rooting depth resulted in a better fit between simulated and observed cumulative and annual rates of groundwater recharge and capillary rise, but in some cases also decreased the simulation quality of both models in terms of IA and RMSE. The results of this calibration indicated that, in addition to a precise determination of the soil water‐retention functions, vegetation parameters such as rooting depth should also be observed. Without such information, the rooting depth is a calibration parameter. However, in some cases, the uncalibrated application of both models also led to an acceptable fit between measured and simulated model outputs.
Capacity, selectivity, and reversibility for nitrate exchange of a layered double‐hydroxide (LDH) mineral in simulated soil solutions and in soil
Authors: Torres‐Dorante Luis Omar , Lammel Joachim , Kuhlmann Hermann , Witzke Thomas , Olfs Hans‐Werner
Published: September 2008

The leaching of nitrate is an important way of N losses from agricultural soils in humid regions. Nitrate leaching is difficult to control as most soils under crop production do not have anion‐exchange properties, and nitrate remains mobile in the solution. The present work evaluated the potential use of a synthetic layered double‐hydroxide (LDH) mineral as a nitrate exchanger in soil. The LDH used was a chloride form of a magnesium‐aluminum layered double hydroxide with the formula: [Mg2+0.82Al3+0.18(OH)2]0.18+[(Cl–)0.18 0.5(H2O)]0.18–. Experiments were carried out in aqueous solutions as well as in soil with the following objectives: (1) to characterize the nitrate adsorption capacity on the LDH, (2) to study its selectivity for nitrate adsorption in solution, (3) to evaluate the reversibility for nitrate exchange, and (4) to study the nitrate adsorption capacity and nitrate diffusion towards the LDH in soil.
Repeated freeze–thaw cycles changed organic matter quality in a temperate forest soil
Authors: Schmitt Andrea , Glaser Bruno , Borken Werner , Matzner Egbert
Published: September 2008

Under temperate climate, the frequency of extreme weather events such as intensive freezing or frequent thawing periods during winter might increase in the future. It was shown that frost and subsequent thawing may affect the fluxes of C and N in soils. In a laboratory study, we investigated the effect of frost intensity and repeated freeze–thaw cycles on the quality and quantity of soil organic matter (SOM) in a Haplic Podzol from a Norway spruce forest. Undisturbed soil columns comprising O layer and top mineral soil were treated as followed: control (+5°C), frost at –3°C, –8°C, and –13°C. After a 2‐week freezing period, frozen soils were thawed at +5°C and irrigated with 80 mm water at a rate of 4 mm d–1. Lignin contents were not significantly affected by repeated freeze–thaw cycles. Phospholipid fatty acid (PLFA) contents decreased in the mineral soil, and PLFA patterns indicate that fungi are more susceptible to soil frost than bacteria. Amounts of both plant and microbial sugars generally decreased with increasing frost intensity. These changes cannot be explained by increased mineralization of sugars or by leaching with DOM nor by a decreased microbial activity and, thus, sugar production with increasing frost intensity. Also physical stabilization of sugars due to frost‐induced changes in soil structure can be ruled out as sugar extraction was carried out on ground bulk soil. Therefore, the only possible explanation for the disappearance of plant and microbial sugars upon soil freezing are chemical alterations of sugar molecules leading to SOM stabilization.
Growth, carcass traits, chemical composition and fatty acid profile in beef from Charolais and Simmental bulls fed different types of dietary lipids
Authors: Bartoň Luděk , Marounek Milan , Kudrna Václav , Bureš Daniel , Zahrádková Radka
Published: September 2008

BACKGROUND: The effect of breed and whole sunflower seed on performance, carcass traits and the composition of meat was evaluated in Charolais (CH) and Simmental (SI) bulls. Samples of musculus longissimus lumborum (MLL) and musculus infraspinatus (MIS) were analysed.

RESULTS: The CH bulls had a lower feed intake per kg of gain, a higher killing‐out percentage and produced more valuable carcasses. The muscles from SI bulls contained more monounsaturated fatty acids (FA) and less saturated FA (in g kg−1 FA) than the muscles from CH bulls. The sunflower seed supplement increased the proportions of linoleic acid and c9t11 conjugated linoleic acid and the ratio of polyunsaturated fatty acids (PUFA) to saturated FA and decreased the index of atherogenicity of FA in meat lipids.

CONCLUSION: The results of this study demonstrated the superiority of the CH over the SI breed in a number of economically important traits. The breed effect on the nutritional quality of meat was ambiguous. Meat lipids of the SI bulls contained more unsaturated FA but also more PUFA n‐6 and a higher PUFA n‐6/PUFA n‐3 ratio. Copyright © 2008 Society of Chemical Industry
The effects of organic and conventional nutrient amendments on strawberry cultivation: Fruit yield and quality
Authors: Hargreaves Jennifer C , Adl M Sina , Warman Philip R , Rupasinghe H P Vasantha
Published: September 2008

BACKGROUND: The nutrition of food is increasingly important to consumers. The popularity of organic food rests partly on the assumption that these products are healthier despite a lack of conclusive evidence. The effects of organic and inorganic fertilizer amendments on parameters of strawberry fruit quality, in terms of sugar, macro‐ and micro‐nutrients concentrations, and total antioxidant capacity were compared.

RESULTS: Treatments did not affect sugar content or total antioxidant capacity. Inorganic fertilizer treatments increased S and Mn content of berries compared to organic treatments. The K and P content of berries differed among years.

CONCLUSIONS:Organic amendments did not increase the fruit quality of strawberries compared to inorganic amendments. Copyright © 2008 Society of Chemical Industry
Angiotensin I‐converting enzyme inhibitory peptides in skim milk fermented with Lactobacillus helveticus 130B4 from camel milk in Inner Mongolia, China
Authors: quan Shuang , Tsuda Harutoshi , Miyamoto Taku
Published: September 2008

BACKGROUND: Angiotensin I‐converting enzyme (ACE) is a dipeptidyl carboxypeptidase associated with the regulation of blood pressure. ACE inhibition results in a lowering of blood pressure. Lactic acid bacteria are known to produce ACE inhibitors during fermentation. Fermented camel milk is the main traditionally fermented dairy food for desert nomads. The beneficial effects of fermented camel milk, which include the prevention of such diseases and conditions as gastroenteritis, tuberculosis and hypertension, have been demonstrated experimentally.

RESULTS:ACE inhibitory activity was observed in fermented milk containing Lactobacillus helveticus 130B4, a strain isolated from traditionally fermented camel milk. The peptide that inhibited ACE was purified from the fermented milk by reverse‐phase high‐performance liquid chromatography. The amino acid sequence of the peptide was identified as Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp (IC50 = 19.9 µmol L−1). The same Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp sequence was found in κ‐casein (κ‐CN) f107–115 from milk. The inhibitory activity of this nonapeptide (κ‐CN f107–115) was almost preserved even after successive digestion with pepsin, trypsin and chymotrypsin. Furthermore, the inhibitory activity of the purified peptide was completely preserved after heat treatment at 100 °C for 20 min.

CONCLUSION:The fermented milk prepared with Lactobacillus helveticus 130B4 contained an ACE inhibitory peptide, κ‐CN 107–115. This fermented milk was expected to have anti‐hypertensive effect after ingestion because the peptide was stable to digestive protease and heat treatment in vitro. Copyright © 2008 Society of Chemical Industry
Micellar Structures of Hydrophilic/Lipophilic and Hydrophilic/Fluorophilic Poly(2‐oxazoline) Diblock Copolymers in Water
Authors: Ivanova Ruzha , Komenda Thomas , Bonné Tune B. , Lüdtke Karin , Mortensen Kell , Pranzas P. Klaus , Jordan Rainer , Papadakis Christine M.
Published: September 2008

Amphiphilic poly(2‐alkyl‐2‐oxazoline) diblock copolymers of 2‐methyl‐2‐oxazoline (MOx) building the hydrophilic block and either 2‐nonyl‐2‐oxazoline (NOx) for the hydrophobic or 2‐(1H,1H′,2H,2H′‐perfluorohexyl)‐2‐oxazoline (FOx) for the fluorophilic block were synthesized by sequential living cationic polymerization. The polymer amphiphiles form core/shell micelles in aqueous solution as evidenced using small‐angle neutron scattering (SANS). Whereas the diblock copolymer micelles with a hydrophobic NOxnblock are spherical, the micelles with the fluorophilic FOxnare slightly elongated, as observed by SANS and TEM. In water, the micelles with fluorophilic and lipophilic cores do not mix, but coexist.

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Impact of obesity on hospitalized patients
Authors: Markoff Brian , Amsterdam Alison
Published: September 2008

Obesity is increasing at an alarming rate worldwide and is a risk factor for cardiac disease, diabetes, and stroke. This provides a challenge for the physicians caring for this patient population in the hospital. Skin integrity, medication dosing, testing, and nutrition are all altered by obesity. We summarize some of the current data on caring for the obese inpatient. Unfortunately, few data on this unique inpatient population exist. Mt Sinai J Med 75:454–459, 2008. © 2008 Mount Sinai School of Medicine
Preoperative evaluation of hospitalized patients
Authors: Sigworth Stephen K.
Published: September 2008

Carefully managing patients undergoing elective surgeries is difficult in the perioperative setting. However, this becomes increasingly complex in patients hospitalized for acute conditions that may or may not be related to the pending surgery. Not only must the consulting physician take into consideration any complications inherent to the surgical procedure, but must also consider all related comorbidities of the acute condition for which the patient was initially hospitalized plus any existing chronic conditions. A careful systematic approach should be undertaken in these circumstances, which consists of (1) perioperative risk stratification, (2) medical optimization, and (3) perioperative risk reduction. Risk stratification is determined by the patient's inherent perioperative cardiac risk factors, whereas medical optimization and risk reduction are actively determined during the hospital course. For perioperative risk stratification, the Revised Cardiac Risk Index is the simplest tool for accurately identifying those patients at increased perioperative risk for cardiac mortality and morbidity. Medical optimization involves performing any necessary preoperative testing that would help identify concurrent undiagnosed medical conditions that might require preoperative intervention or the initiation of certain medication regimens to optimize disease treatment. Lastly, perioperative risk reduction includes any modalities that would be started to decrease the risk of potential perioperative cardiac, pulmonary, or other surgery‐related comorbidities. Mt Sinai J Med 75:442–448, 2008. © 2008 Mount Sinai School of Medicine
Prevention of venous thromboembolism in hospitalized medical patients
Authors: Lenchus Joshua D. , Jaffer Amir K.
Published: September 2008

The hospitalized medical patient in the US today has multiple risk factors for venous thromboembolism (VTE) and is therefore at a significant risk of developing this condition both during hospitalization and after discharge. The American College of Chest Physicians (ACCP) guidelines recommend pharmacologic prophylaxis unless there are contraindications. Low‐molecular‐weight heparins (LMWH) are the preferred class of drugs due to multiple advantages, including daily dosing and a decreased risk of heparin‐induced thrombocytopenia, to name a few. Several emerging oral anticoagulants, including Factor Xa inhibitors and direct thrombin inhibitors, are currently being evaluated in Phase III clinical trials as prophylaxis against VTE in medically ill patients and may some day replace parenteral drugs. Mt Sinai J Med 75:449–453, 2008. © 2008 Mount Sinai School of Medicine
Synthesis of water vapor barrier membrane by coating of poly(vinyl alcohol) substrate with poly(tert‐butyl acrylate)‐silica nanocomposite
Authors: Saito Reiko , Nakagawa Daisuke
Published: September 2008

To prepare a water vapor barrier membrane, organic/silica nanocomposites were used with perhydropolysilazane (PHPS) and poly(tert‐butyl acrylate) (P(tBA)) or poly(tert‐butyl acrylate‐co‐2‐hydroxyethyl methacrylate) (TBAH) on a poly(vinyl alcohol) (PVA) substrate. Water vapor permeability coefficient, Q, of the coated PVA substrates was measured. To prevent crack formation in the organic/silica nanocomposite layer, P(tBA) or TBAH with lower Tg than that of PVA was inserted as a stress relaxation layer between the PVA substrate and the composite layer. The insertion of the stress relaxation layer drastically decreased the Q value. The lowest Q value was observed especially when TBAH was inserted between TBAH/silica nanocomposite layer and the PVA substrate. Observation with a scanning electron microscope (SEM) did not show any crack both in the composite layer and near the interface between layers. It would be due to the good compatibility of the TBAH stress relaxation layer to the TBAH/silica nanocomposite layer and to the PVA substrate. Copyright © 2008 John Wiley & Sons, Ltd.
Polyurethane–acrylate hybrid latexes from miniemulsion polymerization: effect of endgroups on structure and properties
Authors: Wang Chunpeng , Chu Fuxiang , Jin Liwei , Lin Mingtao , Xu Yuzhi , Guyot Alain
Published: September 2008

Polyurethanes (PUs) were prepared by condensation of isophorone diisocyanate and polypropylene glycol (PPG) using butane diol as a chain extender. Methoxy or methacrylic endgroups of PUs were obtained upon reacting the residual isocyanate group (NCO) moiety with either methanol or hydroxyethylmethacrylate (HEMA). The resulted PUs were dissolved in mixtures of acrylic monomers, and then the miniemulsion polymerization was conducted. These PUs were quite efficient hydrophobes for polyurethane (PU)‐acrylate hybrid miniemulsion polymerization. It was also demonstrated from the results of differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) that the microphase separation of soft and hard phase of PUs in hybrid latexes was more significant than that of original PUs. The PU containing the methacrylic endgroup was almost fully cross‐linked during miniemulsion polymerization, resulting in less hard–hard segment of PU hydrogen bond in the hybrid polymer. Some specific morphologies were also discussed from transmission electron microscopy (TEM) and X‐ray photoelectron spectroscopy (XPS). The mechanical properties of these films were studied from the strain–stress curves. Copyright © 2008 John Wiley & Sons, Ltd.
Will layered double hydroxides give nanocomposites with polar or non‐polar polymers?
Authors: Nyambo Calistor , Wang Dongyan , Wilkie Charles A.
Published: September 2008

A preliminary study to determine the compatibility of organically‐modified magnesium aluminum layered double hydroxides with polyethylene, polypropylene, polystyrene, and poly(methyl methacrylate) was carried out by melt blending of the polymers with the layered double hydroxide. Only in the case of poly(methyl methacrylate) was good dispersion and nanocomposite formation obtained. The morphology of all the four systems was examined using X‐ray diffraction and transmission electron microscopy; the systems were also characterized by thermogravimetric analysis and cone calorimetry. Copyright © 2008 John Wiley & Sons, Ltd.