bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term three‐dimensional perfusion culture of human adult bone marrow mononuclear cells in bioreactors
Authors: Schmelzer Eva , Finoli Anthony , Nettleship Ian , Gerlach Jörg C. 
Published: October 2014

ABSTRACTThe construction and long‐term maintenance of three‐dimensional in vitro bone marrow models is of great interest but still quite challenging. Here we describe the use of a multi‐compartment hollow‐fiber membrane based three‐dimensional perfusion bioreactor for long‐term culture of whole human bone marrow mononuclear cells. We also investigated bioreactors with incorporated open‐porous foamed hydroxyapatite scaffolds, mimicking the in vivo bone matrix. Cells in bioreactors with and without scaffolds were cultured to 6 weeks and compared to Petri dish controls. Cells were analyzed for gene expression, surface markers by flow cytometry, metabolic activity, hematopoietic potential, viability, and attachment by immunocytochemistry. Cells in bioreactors were metabolic active during long‐term culture. The percentages of hematopoietic stem cell and mature endothelial cell fractions were maintained in bioreactors. The expression of most of the analyzed genes stabilized and increased after long‐term culture of 6 weeks. Compared to Petri dish culture controls, bioreactor perfusion culture improved in both the short and long‐term, the colony formation unit capacity of hematopoietic progenitors. Cells attached to the ample surface area provided by hydroxyapatite scaffolds. The implementation of a hydroxyapatite scaffold did not influence colony formation capacity, percentages of cell type specific fractions, gene expression, cell viability or metabolic turnover when compared to control cells cultured in bioreactors without scaffolds. In conclusion, three‐dimensional perfusion bioreactor culture enables long‐term maintenance of primary human bone marrow cells, with hydroxyapatite scaffolds providing an in vivo‐like scaffold for three‐dimensional culture. Biotechnol. Bioeng. 2015;112: 801–810. © 2014 Wiley Periodicals, Inc.
Shear stress upregulates IL‐1β secretion by Chlamydia pneumoniae‐ infected monocytes
Authors: Cheeniyil Aswathi , Evani Shankar J. , Dallo Shatha F. , Ramasubramanian Anand K. 
Published: October 2014

ABSTRACTInfectious agents are increasingly implicated in the development and progression of chronic inflammatory diseases. Several lines of evidence suggest that the common intracellular respiratory pathogen, Chlamydia pneumoniae contributes to the well‐established risk factors of atherosclerosis but the exact mechanism is not well understood. It is believed that C. pneumoniae‐infected monocytes travel from the lung to the atherosclerotic foci, during which the cells experience mechanical stimuli due to blood flow. In this work, we characterized the effect of physiological levels of shear stress on C. pneumoniae‐infected human monocytes in an in vitro flow model. We found that a shear stress of 5 dyn/cm2 enhanced the expression of pro‐inflammatory cytokine IL‐1β only in infected, but not in uninfected, monocytes. We also found that this enhancement is due to the upregulation of IL‐1β gene expression due to shear stress. Our results demonstrate that mechanotransduction is an important, heretofore unaddressed, determinant of inflammatory response to an infection. Biotechnol. Bioeng. 2015;112: 838–842. © 2014 Wiley Periodicals, Inc.
Prognosis according to histochemical analysis of liver metastases removed at liver resection
Authors: Brunner S M , Kesselring R , Rubner C , Martin M , Jeiter T , Boerner T , Ruemmele P , Schlitt H J , Fichtner-Feigl S 
Published: October 2014

Abstract

Background
Liver metastases occur in 40–50 per cent of patients with colorectal cancer and determine long-term survival. The aim of this study was to examine the immunological architecture of colorectal liver metastases and its impact on patient survival.

Methods
Specimens from patients with colorectal liver metastases were stained with haematoxylin and eosin and Masson trichrome, immunostained for α-smooth muscle actin, CD4, CD45RO and CD8, and analysed by flow cytometry. In addition to histomorphological evaluation, immunohistochemically stained sections were analysed for cell numbers in the tumour area, infiltrative margin and distant liver stroma separately. These findings were correlated with clinical data and patient outcome.

Results
Tumour containment by a fibrotic capsule around liver metastases was observed in 37·8 per cent of 201 patients and was prognostic for improved survival (median (s.e.) survival 64 (6) and 31 (4) months for patients with capsule and no capsule respectively; P &lt; 0·001) and independently led to higher R0 resection rates (P = 0·040). In multivariable analysis, CD45RO+ cell infiltration at the peritumoral margin with low CD45RO+ cell infiltration in the distant liver stroma (P = 0·001) and fibrotic capsule formation (P = 0·008) both independently prolonged patient survival. Using these two factors, a cellular immune score was designed and shown to stratify patient survival in test and validation samples (both P &lt; 0·001).

Conclusion
Fibrotic capsule formation and localized cell infiltration of colorectal liver metastases by CD45RO+ cells were related to prolonged patient survival. Based on these immunological criteria a cellular immune score was developed to stratify patients according to prognosis.
Outcomes after implementing a tailored endoscopic step-up approach to walled-off necrosis in acute pancreatitis
Authors: Bang J Y , Holt B A , Hawes R H , Hasan M K , Arnoletti J P , Christein J D , Wilcox C M , Varadarajulu S 
Published: October 2014

Abstract

Background
The aim of the study was to compare the outcomes of patients with pancreatic or peripancreatic walled-off necrosis by endoscopy using the conventional approach versus an algorithmic approach based on the collection size, location and stepwise response to intervention.

Methods
This was an observational before–after study of consecutive patients managed over two time intervals. In the initial period (2004–2009) symptomatic patients with walled-off necrosis underwent conventional single transmural drainage with placement of two stents and a nasocystic catheter, followed by direct endoscopic necrosectomy, if required. In the later period (2010–2013) an algorithmic approach was adopted based on size and extent of the walled-off necrosis and stepwise response to intervention. The main outcome was treatment success, defined as a reduction in walled-off necrosis size to 2 cm or less on CT after 8 weeks.

Results
Forty-seven patients were treated in the first interval and 53 in the second. There was no difference in patient demographics, clinical or walled-off necrosis characteristics and laboratory parameters between the groups, apart from a higher proportion of women and Caucasians in the later period. The treatment success rate was higher for the algorithmic approach compared with conventional treatment (91 versus 60 per cent respectively; P &lt; 0·001). On multivariable logistic regression, management based on the algorithm was the only predictor of treatment success (odds ratio 6·51, 95 per cent c.i. 2·19 to 19·37; P = 0·001).

Conclusion
An algorithmic approach to pancreatic and peripancreatic walled-off necrosis, based on the collection size, location and stepwise response to intervention, resulted in an improved rate of treatment success compared with conventional endoscopic management.
Trace quantification of 1‐triacontanol in beagle plasma by GC‐MS/MS and its application to a pharmacokinetic study
Authors: Wang Chunfeng , Fan Ali , Zhu Xiaojie , Lu Yang , Deng Shuhua , Gao Wenchao , Zhang Wei , Liu Qi , Chen Xijing 
Published: October 2014

Abstract1‐Triacontanol (TA), a member of long chain fatty alcohol, has recently been received great attention owing to its antitumor activity. In this study, an accurate, sensitive and selective gas chromatography–tandem mass spectrometry method was developed and validated for the quantification of TA in beagle plasma using 1‐octacosanal as the internal standard (IS) for the first time. With temperature programming, chromatographic separation was carried out on an HP‐5MS column, using helium as carrier gas and argon as collision gas, both at a flow rate of 1 mL/min. TA was analyzed using positive ion electrospray ionization in multiple‐reaction monitoring mode, with the precursor to product ion transitions of m/z 495.6 → 97.0 and m/z 467.5 → 97.0 for TA and the IS, respectively. The lower limit of quantitation, linearity, intra‐ and interday precision, accuracy, stability, extraction recovery and matrix effect of TA were within the acceptable limits. The validated method was successfully applied to a pharmacokinetic study of TA in beagles. Copyright © 2014 John Wiley & Sons, Ltd.
Quantification of heteroclitin D in rat plasma: validation of an LC/MS/MS method and its application in a preclinical pharmacokinetic study
Authors: Zhang Fan , Zhang Nan , Pang Li , Tan Yan , Xu Hong 
Published: October 2014

AbstractA rapid, sensitive and specific liquid chromatography tandem mass spectrometry (LC/MS/MS) method was developed and validated for the quantification of heteroclitin D in rat plasma after using gambogic acid as internal standard (IS). Chromatographic separation was done on a Thermo Hypersil GOLD column (30 × 2.1 mm, 3 µm) using a mobile phase consisting of methanol–water–formic acid (80:20:0.1, v/v/v). The mass spectrometer worked with positive electrospray ionization in multiple reaction monitoring mode, using target ions at [M + H]+ m/z 483.3 for heteroclitin D and [M + H]+ m/z 629.3 for the IS. The standard curve was linear (R2 ≥0.995) over the concentration range 9.98–2080 ng/mL and had good back‐calculated accuracy and precision. The intra‐ and interday precision and accuracy determined on three quality control samples (29.94, 166.4 and 1872 ng/mL) were ≤12.8 and –8.9–3.6%, respectively. The extraction recovery was ≥88.2% and the lower limit of quantification was 9.98 ng/mL. The method was successfully applied to evaluate pharmacokinetics of heteroclitin D in Sprague–Dawley rats following a single intravenous bolus injection of 2.0 mg/kg heteroclitin. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of Amines by Reductive Amination of Aldehydes and Ketones using Co3O4/NGr@C Catalyst
Authors: Pisiewicz Sabine , Stemmler Tobias , Surkus Annette‐Enrica , Junge Kathrin , Beller Matthias 
Published: October 2014

AbstractHeterogenized non‐noble metal‐based catalysts allow for cost‐efficient and environmentally benign hydrogenations. Here, we have developed a straightforward reductive amination methodology using molecular hydrogen in the presence of a Co3O4/NGr@C catalyst system. Various carbonyl compounds were transformed with secondary amines to the corresponding tertiary amines with good to excellent yields and selectivity. The Co3O4/NGr@C catalyst is recycled up to five times without significant loss of activity.
Lipase‐Catalyzed Doubly Enantioselective Ring‐Opening Resolution between Alcohols and Lactones: Synthesis of Chiral Hydroxyl Esters with Two Stereogenic Centers
Authors: Xia Bo , Li Yanyan , Cheng Guilin , Lin Xianfu , Wu Qi 
Published: October 2014

AbstractA novel lipase B from Candida antarctica‐catalyzed doubly enantioselective ring‐opening resolution between racemic alcohols and lactones was developed. By using this strategy, three optically pure compounds including hydroxyl esters with two stereogenic centers and recovered alcohols and lactones were obtained simultaneously in high yields and ee. This process was used for the resolution of various racemic alcohols with different substituent groups and lactones with different ring sizes (four‐ and seven‐ membered lactones). The scale‐up experiments were also successful. Moreover, molecular docking was performed to explain the molecular basis of this doubly enantioselective ring‐opening resolution. As an attractive and efficient strategy, lipase‐catalyzed doubly enantioselective ring‐opening resolution will be widely used in the synthesis of optically pure hydroxyl esters with two stereogenic centers.
Synthesis of Quinoxalines by a Carbon Nanotube–Gold Nanohybrid‐Catalyzed Cascade Reaction of Vicinal Diols and Keto Alcohols with Diamines
Authors: Shah Nimesh , Gravel Edmond , Jawale Dhanaji V. , Doris Eric , Namboothiri Irishi N. N. 
Published: October 2014

AbstractA one‐pot oxidation–condensation method for the synthesis of quinoxalines from readily available benzoins or benzhydrols and 1,2‐phenylenediamines or 2,3‐diaminopyridine by use of a gold–carbon nanotube nanohybrid as a heterogeneous catalyst is reported. Quinoxalines are formed under mild conditions in air and in excellent yields. The simple and efficient methodology offers a safe and sustainable alternative to conventional acid and/or base‐catalyzed thermal processes.
Enhanced Electron Transfer in Enzymatic Bioelectrodes by a Poly(vinyl alcohol) N‐Methyl‐4(4′‐formylstyryl) Pyridinium Methosulfate Acetal Cationic Polymer
Authors: Umasankar Yogeswaran , Ramasamy Ramaraja P. 
Published: October 2014

AbstractA novel method for enzyme immobilization has been developed for use in enzymatic biofuel cell cathodes and anodes. Enzyme immobilization was achieved on a glassy carbon electrode (GCE) modified with multi‐walled carbon nanotubes (MWNTs) using the freestanding cationic polymer poly(vinyl alcohol) N‐methyl‐4(4′‐formylstyryl) pyridiniummethosulfateacetal (PVA‐SbQ). The enzymes entrapped within the polymer chains possess the ability to exchange electrons with the electrode through their respective substrates. The enzyme catalysts studied for biofuel cell cathodes were tyrosinase and laccase, and for biofuel cell anodes alcohol dehydrogenase (ADH) and glucose oxidase (GOx). The advantage of using PVA‐SbQ for enzyme immobilization was demonstrated by using cyclic voltammetry. The experimental results showed that the freestanding PVA‐SbQ polymer chains retained a higher enzyme activity on the MWNT‐modified electrodes compared to cross‐linked PVA‐SbQ chains. Electrochemical impedance spectroscopy was applied to understand the electron‐transfer resistance of cross‐linked PVA‐SbQ. The experimental results also show that enzyme/PVA‐SbQ/MWNT electrodes generate a higher current compared to control electrodes without MWNTs or the polymer. We conclude that the PVA‐SbQ polymer enhances both enzyme immobilization and electrochemical charge transfer in enzyme bioelectrodes, showing promise for the development of high‐performance biofuel cells.
Highly Efficient Membraneless Glucose Bioanode Based on Corynascus thermophilus Cellobiose Dehydrogenase on Aryl Diazonium‐Activated Single‐Walled Carbon Nanotubes
Authors: Ortiz Roberto , Ludwig Roland , Gorton Lo 
Published: October 2014

AbstractWe present an approach for electrode modification by using the oxidoreductase cellobiose dehydrogenase from the ascomycete Corynascus thermophilus (CtCDH). CtCDH is a two‐domain enzyme, in which the catalytic dehydrogenase domain (DHCDH) hosts flavin adenine dinucleotide (FAD) as cofactor and is connected through a flexible linker to a small cytochrome domain with a heme b cofactor (CYTCDH). This domain is responsible for the electron transfer from DHCDH to macromolecular electron acceptors, and is capable of direct electron transfer (DET) with electrode surfaces. CtCDH is optimal at pH values between 7 and 9 and exhibits one of the lowest apparent KM values for glucose (2.4×104 μM) in contrast to the majority of other CDHs, which have acidic optimal pH values and have very low or no activity for glucose. Glassy carbon (GC) electrodes were modified by drop‐casting single‐walled carbon nanotubes (SWCTs) and further modifying with aryl diazonium salts (DS). When adsorbed on such GC‐SWCT‐DS electrodes, CYTCDH showed efficient DET in the presence of a substrate. Six different functional groups for the aryl amines were studied and compared to non‐DS modified GC‐SWCT electrodes. The charge of the grafted aryl amines was investigated and it was found that surfaces modified with aniline, 4‐aminophenol, and 4‐aminobenzoic acid (ABA) contain negative charges at pH 7.4. On the other hand, surfaces modified with p‐phenylenediamine (PD), N,N‐dimethyl‐p‐phenylenediamine, and N,N‐diethyl‐p‐phenylenediamine remain uncharged. To date, the highest DET current density (JMAX=32.5 μA cm−2 for lactose and JMAX=16.2 μA cm−2 for glucose) for a CDH‐modified electrode at human physiological pH can be obtained by using a GC‐SWCT‐ABA CtCDH modified electrode. The use of glutaraldehyde (GA) in GC‐SWCT‐PD‐modified electrodes increases the JMAX twofold. The modified electrodes with DS showed a more negative onset potential for the catalytic current. For GC‐SWCT‐ABA modified electrodes and GC‐SWCT‐PD with GA, a change in the onset potential of −62 and −66 mV, respectively, was found compared with non‐DS modified electrodes. The prepared bioanodes show a loss in response current of 15 % after 9 days of continuous measurements from the original signal in 5 mM glucose, using 50 mM phosphate buffer solution at pH 7.40 at 37 °C.
Effect of Synthesis Parameters on the Electrochemical Properties of High‐Surface‐Area Mesoporous Titanium Oxide with Polypyrrole Nanowires in the Pores
Authors: Smith Luke A. C. , Romer Frederick , Trudeau Michel L. , Smith Mark E. , Hanna John V. , Antonelli David M. 
Published: October 2014

AbstractThis paper describes the synthesis and characterisation of high‐surface‐area mesoporous titanium oxides with polypyrrole nanowires within the pores, and the subsequent variation of synthesis parameters such as polymer‐loading level and pore size to improve performance. These modifications are employed to improve the electron conductivity of the amorphous host and exploit the high internal surface areas of over 800 m2g−1 for potential use as a lithium battery cathode material, once fully optimised, with fast charge‐transfer kinetics expected from the proximity of the vast majority of the redox sites at, or near, the surface of the inner pore walls. A full structural characterisation, in addition to electrochemical assessments, of the composite materials is presented and compared to the pristine mesoporous titanium oxide hosts. The best synthesis conditions were achieved with 5 % polymer loading and the largest pore sized host materials. Excessive polymer loading and smaller pore sizes lead to decreased performance, possibly due to inhibition of Li+ transport. The C18 templated TiO2 composite produced the best capacity retention at 58 % retention, and the C12 composite produced the highest initial capacity of 170 mAh g−1 by using a current density of 1 mAcm−2.
Hierarchical Tubular Structures Grown from the Gel/Liquid Interface
Authors: Steenbjerg Ibsen Casper Jon , Mikladal Bjørn Fridur , Bjørnholt Jensen Uffe , Birkedal Henrik 
Published: October 2014

AbstractThree dimensional hierarchical materials are widespread in nature but are difficult to synthesize by using self‐assembly/organization. Here, we employ a gel–liquid interface to obtain centimeter‐long ∼100 μm diameter tubes with complex mineral wall structures that grow from the interface into solution. The gel, made from gelatin, is loaded with metal chloride salt, whereas the solution is a high pH anion source. Tubes were obtained with a range of cations (Ca2+, Sr2+, Ba2+, Cu2+, and Zn2+) and anions (CO32−and PO43−). The crystalline phases found in the tube walls corresponded to expectations from solution chemistries and phase solubilities. The growth mechanism is found to be akin to that of chemical gardens. The divalent cations modify the strength of the gelatin gel in a manner that involves not only simple electrostatic screening, but also ion‐specific effects. Thus, tubes were not obtained for those ions and/or concentrations that significantly changed the gel’s mechanical structure. At high Cu2+loading, for example, vertical convection bands, not Liesegang bands, were observed in the gels.
Amide‐Functionalized Naphthyridines on a RhII–RhII Platform: Effect of Steric Crowding, Hemilability, and Hydrogen‐Bonding Interactions on the Structural Diversity and Catalytic Activity of Dirhodium(II) Complexes
Authors: Sarkar Mithun , Daw Prosenjit , Ghatak Tapas , Bera Jitendra K. 
Published: October 2014

AbstractFerrocene‐amide‐functionalized 1,8‐naphthyridine (NP) based ligands {[(5,7‐dimethyl‐1,8‐naphthyridin‐2‐yl)amino]carbonyl}ferrocene (L1H) and {[(3‐phenyl‐1,8‐naphthyridin‐2‐yl)amino]carbonyl}ferrocene (L2H) have been synthesized. Room‐temperature treatment of both the ligands with Rh2(CH3COO)4 produced [Rh2(CH3COO)3(L1)] (1) and [Rh2(CH3COO)3(L2)] (2) as neutral complexes in which the ligands were deprotonated and bound in a tridentate fashion. The steric effect of the ortho‐methyl group in L1H and the inertness of the bridging carboxylate groups prevented the incorporation of the second ligand on the {RhII–RhII} unit. The use of the more labile Rh2(CF3COO)4 salt with L1H produced a cis bis‐adduct [Rh2(CF3COO)4(L1H)2] (3), whereas L2H resulted in a trans bis‐adduct [Rh2(CF3COO)3(L2)(L2H)] (4). Ligand L1H exhibits chelate binding in 3 and L2H forms a bridge‐chelate mode in 4. Hydrogen‐bonding interactions between the amide hydrogen and carboxylate oxygen atoms play an important role in the formation of these complexes. In the absence of this hydrogen‐bonding interaction, both ligands bind axially as evident from the X‐ray structure of [Rh2(CH3COO)2(CH3CN)4(L2H)2](BF4)2 (6). However, the axial ligands reorganize at reflux into a bridge‐chelate coordination mode and produce [Rh2(CH3COO)2(CH3CN)2(L1H)](BF4)2 (5) and [Rh2(CH3COO)2(L2H)2](BF4)2 (7). Judicious selection of the dirhodium(II) precursors, choice of ligand, and adaptation of the correct reaction conditions affords 7, which features hemilabile amide side arms that occupy sites trans to the Rh–Rh bond. Consequently, this compound exhibits higher catalytic activity for carbene insertion to the CH bond of substituted indoles by using appropriate diazo compounds, whereas other compounds are far less reactive. Thus, this work demonstrates the utility of steric crowding, hemilability, and hydrogen‐bonding functionalities to govern the structure and catalytic efficacyof dirhodium(II,II) compounds.
Modular Thiol–Ene Chemistry Approach towards Mesoporous Silica Monoliths with Organically Modified Pore Walls
Authors: Göbel Ronald , Hesemann Peter , Friedrich Alwin , Rothe Regina , Schlaad Helmut , Taubert Andreas 
Published: October 2014

AbstractThe surface modification of mesoporous silica monoliths through thiol–ene chemistry is reported. First, mesoporous silica monoliths with vinyl, allyl, and thiol groups were synthesized through a sol–gel hydrolysis–polycondensation reaction from tetramethyl orthosilicate (TMOS) and vinyltriethoxysilane, allyltriethoxysilane, and (3‐mercaptopropyl)trimethoxysilane, respectively. By variation of the molar ratio of the comonomers TMOS and functional silane, mesoporous silica objects containing different amounts of vinyl, allyl, and thiol groups were obtained. These intermediates can subsequently be derivatized through radical photoaddition reactions either with a thiol or an olefin, depending on the initial pore wall functionality, to yield silica monoliths with different pore‐wall chemistries. Nitrogen sorption, small‐angle X‐ray scattering, solid‐state NMR spectroscopy, elemental analysis, thermogravimetric analysis, and redox titration demonstrate that the synthetic pathway influences the morphology and pore characteristics of the resulting monoliths and also plays a significant role in the efficiency of functionalization. Moreover, the different reactivity of the vinyl and allyl groups on the pore wall affects the addition reaction, and hence, the degree of the pore‐wall functionalization. This report demonstrates that thiol–ene photoaddition reactions are a versatile platform for the generation of a large variety of organically modified silica monoliths with different pore surfaces.