bluuebunny/crossref_metadata_2025_split huggingface dataset:
A practical teaching course in directed protein evolution using the green fluorescent protein as a model
Authors: Ruller Roberto , Silva‐Rocha Rafael , Silva Artur , Cruz Schneider Maria Paula , Ward Richard John 
Published: January 2011

AbstractProtein engineering is a powerful tool, which correlates protein structure with specific functions, both in applied biotechnology and in basic research. Here, we present a practical teaching course for engineering the green fluorescent protein (GFP) from Aequorea victoria by a random mutagenesis strategy using error‐prone polymerase chain reaction. Screening of bacterial colonies transformed with random mutant libraries identified GFP variants with increased fluorescence yields. Mapping the three‐dimensional structure of these mutants demonstrated how alterations in structural features such as the environment around the fluorophore and properties of the protein surface can influence functional properties such as the intensity of fluorescence and protein solubility. Biochemistry and Molecular Biology Education Vol. 39, No. 1, pp. 21‐27, 2011
Tracer Experiments to Investigate Granule Growth by Dust Integration in the Fluidized Bed Spray Granulation Process
Authors: Grünewald Gerald , Kind Matthias 
Published: January 2011

AbstractDie Wirbelschicht‐Sprühgranulation dient zur Formulierung von Feststoffen mit hervorragenden anwendungstechnischen Eigenschaften wie z. B. einer guten Redispergierbarkeit und Staubfreiheit. Aufgrund der im Vergleich mit anderen Pulverformulierungsverfahren höheren spezifischen Kosten und Komplexität wird der Prozess nur bei hohen Anforderungen an die Produkte eingesetzt. Unter anderem verursacht der im Prozess durch Abrieb und durch Trocknung nicht‐treffender Sprühtropfen entstehende Staub Störungen. Durch Tracerexperimente wurde der Einfluss verschiedener Prozessparameter auf die Verwertung des rückgeführten Staubes durch Einbindung an feuchte Granulate untersucht.
Metal Complexes of a Structurally Embellished Phosphinane Ligand: An Assessment of Stereoelectronic Effects
Authors: Edwards Peter G. , Kariuki Benson M. , Limon Matthieu , Ooi Li‐Ling , Platts James A. , Newman Paul D. 
Published: January 2011

AbstractThe stereoelectronic features of the pentacyclic phosphane (1S,4R,4aS,5aR,6R,9S,9aS,10aR)‐4,6,11,11,12,12‐hexamethyl‐10‐phenyldodecahydro‐1,4:6,9‐dimethanophenoxaphosphinine (phenop) have been explored through a range of empirical methods including single‐crystal X‐ray structure determinations of the sulfide derivative phenopS (1), the selenide phenopSe (2), [Fe(CO)4(κ1‐phenop)] (3), [W(CO)5(κ1‐phenop)] (4) and trans‐[Rh(κ1‐phenop)(CO)Cl] (5). Cone angles derived from the structural data range from 164–203° with the smaller values being observed for the compounds possessing a phenyl group that is orthogonal to the P–Z bond and the larger values for the compounds expressing a parallel phenyl ring orientation. The cone angle data suggest a moderately bulky phosphane comparable, in steric terms, to PCy3. This is further borne out on inspection of the M–P bond lengths which tend towards the longer end of the known scale. Some flexibility is observed in the central ring which approximates to a boat conformation at one extreme and an envelope at the other depending on the nature of the P‐substituent. The electronic properties of κ1‐phenop have been assessed using a combination of infrared and NMR spectroscopy. The absolute value of the one‐bond coupling constants 1JP‐Se and 1JP‐Rh are very close to those reported for PPh3, suggesting a close analogy between κ1‐phenop and the well known triphenylphosphane. In addition, relevant υ(CO) stretches in the IR spectra of the metal carbonyl complexes also closely mimic those for the analogous complexes containing PPh3. These conclusions are supported by molecular electrostatic potential calculations at the DFT level which place phenop close to PPh3 in terms of lone pair availability.
Lumped parameter sensitivity analysis of a distributed hydrological model within tropical and temperate catchments
Authors: Cuo Lan , Giambelluca Thomas W. , Ziegler Alan D. 
Published: January 2011

AbstractParameter sensitivity of the Distributed Hydrology‐Soil‐Vegetation Model (DHSVM) was studied in two contrasting environments: (1) Pang Khum Experimental Watershed (PKEW) in tropical northern Thailand; and (2) Cedar River basin (CRB) in Washington State of the temperate US Pacific Northwest. The analysis shows that for both basins, the most sensitive soil parameters were porosity, lateral saturated hydraulic conductivity, and the exponential decrease rate of lateral saturated hydraulic conductivity with soil depth. The most sensitive vegetation parameters were leaf area index, vegetation height, vapour pressure deficit, minimum stomatal resistance (for both grassland and forest scenarios), hemisphere fractional coverage, overstory fractional coverage, and trunk space (for the forest scenario only). Parameter sensitivity was basin‐specific, with the humid, temperate CRB being more influenced by vegetation parameters, while tropical PKEW was more influenced by soil properties. Increases and decreases in parameter values resulted in opposite and unequal changes in bias and root mean square error (RMSE), indicating the non‐linearity of physical process represented in the hydrological model. Copyright © 2011 John Wiley & Sons, Ltd.
Physicochemical analysis of poly‐L‐lysine: An insight into the changes induced in lysine residues of proteins on modification with glucose
Authors: Ansari Nadeem Ahmad , Moinuddin  , Ali Rashid 
Published: January 2011

AbstractNonenzymatic glycation of macromolecules, especially proteins, takes place mainly due to hyperglycemia in diabetes mellitus. Increased glycolysis during cancer and inflammation during rheumatoid arthritis also contribute to the process of glycation. As lysine residues of proteins are a potential site for glycation, it could be used as a marker for early glycation induced changes in lysine‐rich proteins. In the present study, a lysine polymer was incubated with increasing concentrations of glucose for 24 h, and the early glycation product was evaluated by nitroblue tetrazolium assay. The modified polymer together with unmodified one was characterized by gel electrophoresis and UV, fluorescence spectroscopy. Results of the study clearly demonstrate that structural perturbation in the lysine polymer was caused by the early glycation. Further study on detection of antibodies against theglycated proteins in diseased patients might be helpful in early diagnosis of the disease. © 2011 IUBMB IUBMB Life, 63(1): 26–29, 2011
Ubiquinol‐induced gene expression signatures are translated into altered parameters of erythropoiesis and reduced low density lipoprotein cholesterol levels in humans
Authors: Schmelzer Constance , Niklowitz Petra , Okun Jürgen G. , Haas Dorothea , Menke Thomas , Döring Frank 
Published: January 2011

AbstractStudies in vitro and in mice indicate a role for Coenzyme Q10 (CoQ10) in gene expression. To determine this function in relationship to physiological readouts, a 2‐week supplementation study with the reduced form of CoQ10 (ubiquinol, Q10H2, 150 mg/d) was performed in 53 healthy males. Mean CoQ10 plasma levels increased 4.8‐fold after supplementation. Transcriptomic and bioinformatic approaches identified a gene–gene interaction network in CD14‐positive monocytes, which functions in inflammation, cell differentiation, and peroxisome proliferator‐activated receptor‐signaling. These Q10H2‐induced gene expression signatures were also described previously in liver tissues of SAMP1 mice. Biochemical and NMR‐based analyses showed a reduction of low density lipoprotein (LDL) cholesterol plasma levels after Q10H2 supplementation. This effect was especially pronounced in atherogenic small dense LDL particles (19–21 nm, 1.045 g/L). In agreement with gene expression signatures, Q10H2 reduces the number of erythrocytes but increases the concentration of reticulocytes. In conclusion, Q10H2 induces characteristic gene expression patterns, which are translated into reduced LDL cholesterol levels and altered parameters of erythropoiesis in humans. © 2011 IUBMB IUBMB Life, 63(1): 42–48, 2011
Myocardin‐related transcription factor‐A induces cardiomyocyte hypertrophy
Authors: Liao Xing‐Hua , Wang Nan , Liu Qing‐Xi , Qin Tao , Cao Bo , Cao Dong‐Sun , Zhang Tong‐Cun 
Published: January 2011

AbstractMyocardin is a remarkably potent transcriptional coactivator expressed specifically in cardiac muscle lineages and smooth muscle cells during postnatal development. Myocardin shares homology with myocardin‐related transcription factor‐A (MRTF‐A), which are expressed in a broad range of embryonic and adult tissues. Our previous results show that myocardin induces cardiac hypertrophy. However, the effects of MRTF‐A in cardiac hypertrophy remain poorly understood. Our present work further demonstrates that myocardin plays an important role in inducing hypertrophy. At the same time, we find that overexpression of MRTF‐A in neonatal rat cardiomyocytes might induce cardiomyocyte hypertrophy. Furthermore, MRTF‐A expression is induced in phenylephrine, angiotensin‐II, and transforming growth factor‐β‐stimulated cardiac hypertrophy, whereas a dominant‐negative form of MRTF‐A or MRTF‐A siRNA strongly inhibited upregulation of hypertrophy genes in response to hypertrophic agonists in neonatal rat cardiomyocytes. Our studies indicate that besides myocardin, MRTF‐A might play an important role in cardiac hypertrophy. Our findings provide novel evidence for the future studies to explore the roles of MRTFs in cardiac hypertrophy. © 2011 IUBMB IUBMB Life, 63(1):54–61, 2011.
Water–ice phase transition probed by Raman spectroscopy
Authors: Đuričković Ivana , Claverie Rémy , Bourson Patrice , Marchetti Mario , Chassot Jean‐Marie , Fontana Marc D. 
Published: January 2011

AbstractRaman spectroscopy was used to study the liquid–solid water phase transition. Special attention was devoted to the OHstretching band of the Raman spectrum, which shows monotonous changes in the temperature range between 10 and − 15 °C. The interpretation of this spectral change, as well as a careful analysis of its integrated scattered intensity, led to a spectral marker that allows the determination of the water phase (liquid or solid), and the efficient identification of the liquid–solid phase transition itself. Copyright © 2011 John Wiley & Sons, Ltd.
Monitoring of local pH in photodynamic therapy‐treated live cancer cells using surface‐enhanced Raman scattering probes
Authors: Bálint Štefan , Rao Satish , Marro Mónica , Miškovský Pavol , Petrov Dmitri 
Published: January 2011

AbstractThe local pH inside individual live glioma (U‐87 MG) cancer cells was monitored after treatment by the photodynamic therapy drug 6‐methyl‐1,3,8‐trihydroxyanthraquinone (emodin). The cellular pH is tracked by the real‐time measurement of the surface‐enhanced Raman scattering (SERS) from a probe that is embedded in the cell. The probe is a micrometer‐sized silica bead that is covered by nanosized silver colloids, which enhance Raman signal, and 4‐mercaptobenzoic acid (pMBA) whose molecular vibrations and resulting Raman spectrum are sensitive to pH. Visible excitation at different light dosages is used to activate the drug. The results indicate cell maintenance of internal pH and cell death at low and high light dosage, respectively. We demonstrate that these SERS probes are an effective tool for ex vivo pH monitoring in a live cell thanks to their high optical sensitivity and noninvasive usage. Copyright © 2011 John Wiley & Sons, Ltd.
Raman study of ultrathin Fe3O4 films on GaAs(001) substrate: stoichiometry, epitaxial orientation and strain
Authors: Zhang Jun , Tan PingHeng , Zhao WeiJie , Lu Jun , Zhao JianHua 
Published: January 2011

AbstractThe growth and characterization of high‐quality ultrathin Fe3O4 films on semiconductor substrates is a key step for spintronic devices. A stable, single‐crystalline ultrathin Fe3O4 film on GaAs(001) substrate is obtained by post‐growth annealing of epitaxial Fe film with thicknesses of 5 and 12 nm in air. Raman spectroscopy shows a high ability to convincingly characterize the stoichiometry, epitaxial orientation and strain of such ultrathin Fe3O4 films. Polarized Raman spectroscopy confirms the unit cell of Fe3O4 films is rotated by 45° to match that of the Fe (001) layer on GaAs, which results in a built‐in strain of − 3.5% in Fe3O4 films. The phonon strain‐shift coefficient(−126 cm−1) of the A1g mode is proposed to probe strain effect and strain relaxation of thin Fe3O4 films on substrates. It can be used to identify whether the Fe layer is fully oxidized to Fe3O4 or not. Copyright © 2011 John Wiley & Sons, Ltd.
pH‐Sensitive Pentablock Copolymer Nanocapsules as Nontoxic and Efficient Gene Carriers
Authors: Lee Min Sang , Jang Yeon Lim , Huynh Dai Phu , Huynh Cong Truc , Lee Yuhan , Chae Su Young , Kim Sun Hwa , Park Tae Gwan , Lee Doo Sung , Jeong Ji Hoon 
Published: January 2011

AbstractA biodegradable amphiphilic pentablock copolymer PAE‐PCL‐PEG‐PCL‐PAE with a pH‐sensitive unit was synthesized for use as a nontoxic, biodegradable carrier for gene delivery by forming nanocapsules entrapping nucleic acid drugs. The PAE block can interact with plasmid DNA to form polyelectrolyte complexes in an acidic environment. At physiological pH, the PAE blocks are deprotonated and form an insoluble skin, resulting in the formation of nanocapsules that encapsulate plasmid DNA. The surface charges of the nanocapsules became almost neutral at pH = 7.4, and their size ranged from 210 to 280 nm. The nanocapsule maintained most of its transfection efficiency even in the presence of serum. These nanocapsules are therefore potential carriers for systemic gene therapy. magnified image
The Use of Microfluidics in Rheology
Authors: Hu Xin , Boukany Pouyan E. , Hemminger Orin L. , Lee L. James 
Published: January 2011

AbstractThe combination of microfluidics and fluorescent‐labeled DNA molecules in rheology provides a unique opportunity to relate the microstructure of polymer molecules to their macroscopic properties. For example, the direct visualization of a model polymer system such as single DNA dynamics of individual DNA molecules, improves our understanding of the rheological behavior of dilute and concentrated polymer solutions. This review summarizes the microfluidic rheology for synthetic polymer and DNA solutions, including both experimental and simulation efforts, in investigating dilute and concentrated polymer solutions.magnified image
Bubble Behaviour in Fluidised Beds at Elevated Pressures
Authors: Godlieb Willem , Deen Niels G. , Kuipers Johannes A. M. 
Published: January 2011

AbstractLow density polyethylene and polypropylene are produced at large scale via the Unipol process. In this process catalyst particles are fluidised with monomer gas and grow into polymeric particles up to a size of 1 mm. The process is operated at 20–25 bar. Pressure plays an important role in the hydrodynamics of the fluidised bed, which is reflected in bubble behaviour, particle mixing and heat transfer characteristics. Despite decades of research these effects are not completely understood. We use a state‐of‐the art discrete particle model (DPM) to simulate fluidisation behaviour at different pressures. The DPM is the most fundamental model suited for studying pressure effects in gas‐fluidised beds, since it accurately represents the gas–particle interaction and particle–particle interaction. Fourier analysis of the bed pressure drop fluctuations and bubble properties (bubble velocity, bubble size, coalescence and break‐up) obtained from a sophisticated bubble detection algorithm are presented. magnified image
Relative singularity categories and Gorenstein‐projective modules
Authors: Chen Xiao‐Wu 
Published: January 2011

AbstractWe introduce the notion of relative singularity category with respect to a self‐orthogonal subcategory ω of an abelian category. We introduce the Frobenius category of ω‐Cohen‐Macaulay objects, and under certain conditions, we show that the stable category of ω‐Cohen‐Macaulay objects is triangle‐equivalent to the relative singularity category. As applications, we rediscover theorems by Buchweitz, Happel and Beligiannis, which relate the stable categories of (unnecessarily finitely‐generated) Gorenstein‐projective modules to the (big) singularity categories of rings. For the case where ω is the additive closure of a self‐orthogonal object, we relate the category of ω‐Cohen‐Macaulay objects to the category of Gorenstein‐projective modules over the opposite endomorphism ring of the self‐orthogonal object. We prove that for a Gorenstein ring, the stable category of Gorenstein‐projective modules is compactly generated and its compact objects coincide with finitely‐generated Gorenstein‐projective modules up to direct summand. © 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Salvage of compromised free flaps in trauma cases with combined modalities
Authors: Egozi D. , Fodor L. , Ullmann Y. 
Published: January 2011

AbstractUsing the microsurgical technique for reconstruction in trauma cases represents a challenge for the reconstructive surgeon. Several methods of salvaging of a compromised free flap have been reported, among them: intravenous heparin washing, thrombolitic therapy, thrombectomy, use of grafts and others. Here, we present our experience from nine cases and a review of the literature regarding the use of various modalities for free flap salvage in trauma cases, and their results. Data was collected from trauma cases in our institutions over a period of 2 years, where reconstruction was performed using microsurgical techniques, and where subsequent complications required some type of salvage procedure. The techniques that were used for the salvage included: intravascular irrigation with heparin, papaverine and lidocaine; administration of continuous intravenous heparin, use of the Fogarty catheter, flap washing with streptokinase, and adventitia stripping. The free flaps used were latissimus dorsi, serratus anterior, and the anteromedial thigh flap. Either vein or artery thromboses were identified during the procedure or immediately after surgery in seven patients. Two patients had prolonged spasms of the recipient artery with low flow. In all cases, the No. 2 Fogarty catheter was used for thrombectomy and also for release of the vessel spasm. There was only one complete failure among these patients, and partial necrosis was encountered in three. From our experience and review of the literature, we offer an algorithm for determining treatment strategies in a range of flap salvage situations. © 2011 Wiley–Liss, Inc. Microsurgery, 2011.
2D correlation spectra edited by the sign of relative coupling constant
Authors: Blechta Vratislav , Schraml Jan 
Published: January 2011

AbstractModifications (CSEc and CSEh) of recently published SQSQc and SQSQh pulse sequences are proposed and tested on detection of small (∼2 Hz) signed silicon–carbon coupling constants. The new sequences increase signal intensity by simplifying the spectra. The signals are about four times stronger than in SQSQc or SQSQh spectra, achieving the sensitivity of E.COSY‐type experiment. The information about sign and magnitude of the coupling is preserved. CSEc and CSEh spectra for two silicon compounds are presented and compared. The two new sequences allow editing of heteronuclear correlation spectra according to the sign of the selected heteronuclear coupling constants. Copyright © 2011 John Wiley & Sons, Ltd.
Substrate selection in hearts subjected to ischemia/reperfusion: role of cardioplegic solutions and gender
Authors: Alves Marco G. , Oliveira Paulo J. , Carvalho Rui A. 
Published: January 2011

AbstractIn conditions of ischemia/reperfusion (I/R), the relative use of all available substrates by the heart has a significant effect on the recovery of the organ. This substrate preference in perfused hearts is influenced by ischemia. We followed the metabolic fate of [U‐13C]glucose and [3‐13C]lactate in hearts preserved in Celsior (Cs) and histidine buffer solution (HBS) for 4 or 6 h and subsequently perfused with a Krebs–Henseleit solution (KH) containing [U‐13C]glucose and [3‐13C]lactate. We also assessed gender‐specific metabolic modulation in our I/R experimental conditions. Hearts from male and female Wistar rats (6–8 weeks) were subjected to moderate (0–240 min) or prolonged (240–360 min) cold ischemia whilst immersed in Cs and HBS, and perfused for 30 min with KH containing [U‐13C]glucose and [3‐13C]lactate. After perfusion, hearts were freeze‐clamped and metabolites were extracted for 13C NMR isotopomer analysis. In control conditions, there were no differences with regard to lactate origin in hearts from males and females. After 6 h of preservation in Cs, lactate origin was mostly from [U‐13C]glucose in hearts from males and from [3‐13C]lactate in hearts from females. During the 6 h of organ preservation in HBS, the lactate pool showed a strong contribution from unenriched sources in male hearts and from [U‐13C]glucose in female hearts. The glutamate C2/C4 ratio was stable or increased in hearts from females after I/R, and the alanine index increased in hearts from both males and females. Octanoate was, as predicted, the preferential substrate during perfusion. Glucose and lactate suffer a distinct metabolic fate in our I/R conditions, which is related to the cardioplegic solution used during organ storage, and the gender. Hearts from females appear to be less sensitive to I/R injury, and heart preservation in HBS proved to be effective in enhancing anaplerosis during perfusion, especially in hearts from females. Copyright © 2011 John Wiley & Sons, Ltd.
Symptoms of attention‐deficit/hyperactivity disorder in long‐term survivors of childhood leukemia
Authors: Krull Kevin R. , Khan Raja B. , Ness Kirsten K. , Ledet Davonna , Zhu Liang , Pui Ching‐Hon , Howard Scott C. , Srivastava Deo Kumar , Sabin Noah D. , Hudson Melissa M. , Morris E. Brannon 
Published: January 2011

AbstractBackgroundSurvivors of childhood acute lymphoblastic leukemia (ALL) sometimes have clinical features that suggest attention‐deficit/hyperactivity disorder (ADHD), though few studies have examined specific symptoms in survivors.ProcedureLong‐term survivors of childhood ALL (n = 161) received a neurological examination, while parents completed rating scales to establish formal criteria for ADHD. Symptom profiles were generated and compared across demographic and treatment characteristics, as well as medical tests associated with brain pathology.ResultsPrevalence rates of ADHD were similar in survivors (10.5%) compared to those reported in the general population (7–10%). However, 25.5% of survivors reported symptoms that impair functioning in multiple settings, with attention problems being most common. These symptoms were associated with cranial radiation therapy (CRT) (mean inattentive symptoms [SD] = 3.6 [3.19] for group treated with CRT vs. 1.6 [2.40] for non‐CRT group, P = 0.0006), and survivors who demonstrated impaired anti‐saccades during the neurologic exam (mean inattentive symptoms [SD] = 3.4 [3.29] for those with impaired anti‐saccades vs. 1.4 [2.41] for those with normal anti‐saccades; P = 0.0004).ConclusionsThe presence of a neurologically‐based phenotype of attention problems in survivors of leukemia that is not fully captured by the syndrome of ADHD suggests that treatments specific to childhood ALL should be explored. Pediatr Blood Cancer 2011; 57: 1191–1196. © 2011 Wiley Periodicals, Inc.