bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomineralisation als Inspirationsquelle für die Materialchemie
Authors: Nudelman Fabio , Sommerdijk Nico A. J. M. 
Published: June 2012

AbstractLebende Organismen bilden spezielle organisch‐anorganische Hybridmaterialien wie Knochen, Zähne und Schalen, die an ihre jeweilige Funktion hervorragend angepasst sind. Das hat Physiker, Chemiker und Materialwissenschaftler dazu angeregt, solche Strukturen mit besonderen Eigenschaften nachzuahmen. In diesem Aufsatz beschreiben wir, welche aus der Natur entlehnten Strategien man verwendet, um Biominerale aufzubauen und ihre Eigenschaften für biomedizinische, industrielle und technische Anwendungen abzustimmen. Biologisch inspirierte Ansätze wie molekulares Templatieren, supramolekulares Templatieren, organisierte Oberflächen und Phagen‐Display werden ebenso diskutiert wie Methoden, mit denen Struktur und Funktion von Biomineralen nachgeahmt werden können. Wir zeigen, welche Rolle die In‐situ‐Untersuchung und In‐situ‐Visualisierung für das Verständnis der biologisch inspirierten Materialien und die Kontrolle und Optimierung ihrer Herstellung spielen. Biominerale bilden sich in wässrigen Medien unter Normalbedingungen, sodass aus ihnen abgeleitete Herstellungsverfahren ökologisch vorteilhafter sind als die herkömmlichen Methoden.
A protocol to remove colored metabolites and other inhibitors from plant tissues to facilitate RNA isolation suitable for downstream applications
Authors: Singh Ravi S. , Kumar Sanjay 
Published: June 2012

AbstractThis work developed a protocol to remove colored metabolites and other interfering substances to facilitate RNA isolation. These metabolites otherwise hinder RNA isolation and downstream applications. The developed protocol used sodium dodecyl sulphate, ethylenediamine tetra‐acetic acid, and ethanol in a definite ratio that removed the said metabolites from the tissue and aided isolation of RNA using the existing methods. The protocol was developed for red colored roots of Arnebia euchroma and was extended to other colored tissues [rhizome of Rheum australe (Himalayan Rhubarb) and taproot of Daucus carota (purple carrot)] with success. Without inclusion of our protocol, the existing methods could not isolate good quality RNA from these tissues. RNA isolated by the developed protocol had A260/280 ratio of 1.88–1.93, A260/230 ratio of 1.94–2.0, and RNA integrity number of 6.3–8.0. RNA was amenable to downstream applications such as reverse‐transcription polymerase chain reaction and primer extension assay. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Genetically engineered Escherichia coli FBR5: Part II. Ethanol production from xylose and simultaneous product recovery
Authors: Qureshi N. , Dien B. S. , Liu S. , Saha B. C. , Cotta M. A. , Hughes S. , Hector R. 
Published: June 2012

AbstractIn these studies, concentrated xylose solution was fermented to ethanol using Escherichia coli FBR5 which can ferment both lignocellulosic sugars (hexoses and pentoses). E. coli FBR5 can produce 40–50 g L−1 ethanol from 100 g L−1 xylose in batch reactors. Increasing sugar concentration beyond this level results in the loss of sugar with the reactor effluent thus affecting the process yield adversely. In a nonintegrated system without simultaneous product removal more than 120 g L−1 xylose was left unused of the 220 g L−1 that was fed into the reactor. In contrast to this, application of simultaneous product removal by gas stripping was able to relieve product inhibition and the culture was able to use 216.6 g L−1 xylose thus producing 140 g L−1 (based on reactor volume) ethanol resulting in a product yield of 0.48. The product stream achieved an ethanol concentration up to 148.41 g L−1. This process has potential for greatly improving the performance of E. coli FBR5 where the strain can ferment all the lignocellulosic sugars to ethanol and gas stripping can be applied to recover product. Published 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Genetically engineered Escherichia coli FBR5: Part I. Comparison of high cell density bioreactors for enhanced ethanol production from xylose
Authors: Qureshi N. , Dien B. S. , Liu S. , Saha B. C. , Hector R. , Cotta M. A. , Hughes S. 
Published: June 2012

AbstractFive reactor systems (free cell batch, free cell continuous, entrapped cell immobilized, adsorbed cell packed bed, and cell recycle membrane reactors) were compared for ethanol production from xylose using Escherichia coli FBR5. In the free cell batch and free cell continuous reactors (continuous stirred tank reactor‐CSTR) productivities of 0.84 gL−1 h−1 and 1.77 gL−1 h−1 were achieved, respectively. A cell recycle membrane reactor resulted in the highest productivity of 55.56 gL−1 h−1, which is an increase of 66‐fold (e.g., 6614%) over the batch reactor. Calcium alginate gel CSTR resulted in a productivity of 2.04 gL−1 h−1 whereas adsorbed cell packed bed reactor resulted in a productivity of 4.39 gL−1 h−1. In the five reactor systems, ethanol concentrations ranged from 18.9 to 40.30 gL−1 with metabolic yields from 0.44 to 0.51. Published 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
The impact of fabrication parameters and substrate stiffness in direct writing of living constructs
Authors: Tirella Annalisa , Ahluwalia Arti 
Published: June 2012

AbstractBiomolecules and living cells can be printed in high‐resolution patterns to fabricate living constructs for tissue engineering. To evaluate the impact of processing cells with rapid prototyping (RP) methods, we modeled the printing phase of two RP systems that use biomaterial inks containing living cells: a high‐resolution inkjet system (BioJet) and a lower‐resolution nozzle‐based contact printing system (PAM2). In the first fabrication method, we reasoned that cell damage occurs principally during drop collision on the printing surface, in the second we hypothesize that shear stresses act on cells during extrusion (within the printing nozzle). The two cases were modeled changing the printing conditions: biomaterial substrate stiffness and volumetric flow rate, respectively, in BioJet and PAM2. Results show that during inkjet printing impact energies of about 10−8 J are transmitted to cells, whereas extrusion energies of the order of 10−11 J are exerted in direct printing. Viability tests of printed cells can be related to those numerical simulations, suggesting a threshold energy of 10−9 J to avoid permanent cell damage. To obtain well‐defined living constructs, a combination of these methods is proposed for the fabrication of scaffolds with controlled 3D architecture and spatial distribution of biomolecules and cells. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Identifying and Characterizing Binding Sites on the Irreversible Inhibition of Human Glutathione S‐Transferase P1‐1 by S‐Thiocarbamoylation
Authors: Quesada‐Soriano Indalecio , Primavera Alessandra , Casas‐Solvas Juan M. , Téllez‐Sanz Ramiro , Barón Carmen , Vargas‐Berenguel Antonio , Lo Bello Mario , García‐Fuentes Luís 
Published: June 2012

AbstractHuman glutathione S‐transferase P1‐1 (hGST P1‐1) is involved in cell detoxification processes through the conjugation of its natural substrate, reduced glutathione (GSH), with xenobiotics. GSTs are known to be overexpressed in tumors, and naturally occurring isothiocyanates, such as benzyl isothiocyanate (BITC), are effective cancer chemopreventive compounds. To identify and characterize the potential inhibitory mechanisms of GST P1‐1 induced by isothiocyanate conjugates, we studied the binding of GST P1‐1 and some cysteine mutants to the BITC–SG conjugate as well as to the synthetic S‐(N‐benzylcarbamoylmethyl)glutathione conjugate (BC–SG). We report here the inactivation of GST P1‐1 through the covalent modification of two Cys47 residues per dimer and one Cys101. The evidence has been compiled by isothermal titration calorimetry (ITC) and electrospray ionization mass spectrometry (ESI‐MS). ITC experiments suggest that the BITC–SG conjugate generates adducts with Cys47 and Cys101 at physiological temperatures through a corresponding kinetic process, in which the BITC moiety is covalently bound to these enzyme cysteines through an S‐thiocarbamoylation reaction. ESI‐MS analysis of the BITC–SG incubated enzymes indicates that although the Cys47 in each subunit is covalently attached to the BITC ligand moiety, only one of the Cys101 residues in the dimer is so attached. A plausible mechanism is given for the emergence of inactivation through the kinetic processes with both cysteines. Likewise, our molecular docking simulations suggest that steric hindrance is the reason why only one Cys101 per dimer is covalently modified by BITC–SG. No covalent inactivation of GST P1‐1 with the BC–SG inhibitor has been observed. The affinities and inhibitory potencies for both conjugates are high and very similar, but slightly lower for BC–SG. Thus, we conclude that the presence of the sulfur atom from the isothiocyanate moiety in BITC–SG is crucial for its irreversible inhibition of GST P1‐1.
Synthesis and Characterization of a Hypoxia‐Sensitive MRI Probe
Authors: Rojas‐Quijano Federico A. , Tircsó Gyula , Tircsóné Benyó Enikő , Baranyai Zsolt , Tran Hoang Huan , Kálmán Ferenc K. , Gulaka Praveen K. , Kodibagkar Vikram D. , Aime Silvio , Kovács Zoltán , Sherry A. Dean 
Published: June 2012

AbstractTissue hypoxia occurs in pathologic conditions, such as cancer, ischemic heart disease and stroke when oxygen demand is greater than oxygen supply. An imaging method that can differentiate hypoxic versus normoxic tissue could have an immediate impact on therapy choices. In this work, the gadolinium(III) complex of 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid (DOTA) with a 2‐nitroimidazole attached to one carboxyl group via an amide linkage was prepared, characterized and tested as a hypoxia‐sensitive MRI agent. A control complex, Gd(DO3A‐monobutylamide), was also prepared in order to test whether the nitroimidazole side‐chain alters either the water proton T1 relaxivity or the thermodynamic stability of the complex. The stabilities of these complexes were lower than that of Gd(DOTA)− as expected for mono‐amide derivatives. The water proton T1 relaxivity (r1), bound water residence lifetime (τM) and rotational correlation time (τR) of both complexes was determined by relaxivity measurements, variable temperature 17O NMR spectroscopy and proton nuclear magnetic relaxation dispersion (NMRD) studies. The resulting parameters (r1=6.38 mM−1 s−1 at 20 MHz, τM=0.71 μs, τR=141 ps) determined for the nitroimidazole derivative closely parallel to those of other Gd(DO3A‐monoamide) complexes of similar molecular size. In vitro MR imaging experiments with 9L rat glioma cells maintained under nitrogen (hypoxic) versus oxygen (normoxic) gas showed that both agents enter cells but only the nitroimidazole derivative was trapped in cells maintained under N2 as evidenced by an approximately twofold decrease in T1 measured for hypoxic cells versus normoxic cells exposed to this agent. These results suggest that the nitroimidazole derivative might serve as a molecular reporter for discriminating hypoxic versus normoxic tissues by MRI.
Absolute Configuration Determination and Convenient Asymmetric Synthesis ofcis‐3‐(9‐Anthryl)cyclohexanol with Proline as a Catalyst
Authors: Wysocki Jędrzej , Kwit Marcin , Gawronski Jacek 
Published: June 2012

ABSTRACTcis‐(3R)‐(9‐anthryl) derivative of cyclohexanol was conveniently obtained in enantiomerically pure form from 2‐cyclohexenone using asymmetric Michael addition of anthrone catalyzed byl‐proline in a key step. The absolute configuration of the addition product was unequivocally determined by means of electronic circular dichroism measurements combined with calculation of the circular dichroism spectrum by using a density functional theory method.Chirality 24:833–839, 2012. © 2012 Wiley Periodicals, Inc.
Future Technologies – Times Changing for Inorganic Raw Materials Resources
Authors: Sextl Gerhard , Brämer Thilo , Gellermann Carsten , Reller Armin 
Published: June 2012

AbstractÄhnlich wie beim Erdöl wird es bei vielen Metallen zukünftig eine Peak‐Problematik geben, denn mittlerweile sind selbst die ergiebigen Förderstätten vieler anorganischer Rohstoffe erschöpft. Auch bei den Primärrohstoffen ist der Metallgehalt der Erze inzwischen so gering, dass deren Ausbeute immer ressourcen‐ und energieaufwendiger wird. Anhand von Anwendungsbeispielen wird gezeigt, dass viele Rohstoffe, auch wenn sie nur einen geringen Anteil im Produkt ausmachen, trotzdem großen Einfluss auf unser tägliches Leben haben. Eine Wiederaufbereitung und Rückführung dieser wertvollen Ressourcen in die Wertstoffkreisläufe steht deshalb ganz oben auf der gesellschaftlichen Agenda der nächsten Jahrzehnte. Anhand ausgewählter Beispiele werden der Stand und die Entwicklung der gegenwärtigen Aufbereitungsprozesse beschrieben.
C‐X‐C chemokine receptor 7
Authors: Yates Travis J. , Knapp Judith , Gosalbez Miguel , Lokeshwar Soum D. , Gomez Christopher S. , Benitez Anaid , Ekwenna Obi O. , Young Ezekiel E. , Manoharan Murugesan , Lokeshwar Vinata B. 
Published: June 2012

AbstractBACKGROUND:C‐X‐C chemokine receptor 4 (CXCR4) and CXCR7 are 7‐transmembrane chemokine receptors of the stroma‐derived factor (SDF‐1). CXCR4, but not CXCR7, has been examined in bladder cancer (BCa). This study examined the functional and clinical significance of CXCR7 in BCa.METHODS:CXCR4 and CXCR7 levels were measured in BCa cell lines, tissues (normal = 25; BCa = 44), and urine specimens (n = 186) by quantitative polymerase chain reaction and/or immunohistochemistry. CXCR7 function in BCa cells were examined by transient transfections using a CXCR7 expression vector or small interfering RNA.RESULTS:In BCa cell lines, CXCR7 messenger RNA levels were 5‐ to 37‐fold higher than those for CXCR4. Transient overexpression of CXCR7 in BCa cell lines promoted growth and chemotactic motility. CXCR7 colocalized and formed a functional complex with epidermal growth factor receptor, phosphoinositide 3‐kinase/Akt, Erk, and src and induced their phosphorylation. CXCR7 also induced up‐regulation of cyclin‐D1 and bcl‐2. Suppression of CXCR7 expression reversed these effects and induced apoptosis. CXCR7 messenger RNA levels and CXCR7 staining scores were significantly (5‐ to 10‐fold) higher in BCa tissues than in normal tissues (P < .001). CXCR7 expression independently associated with metastasis (P = .019) and disease‐specific mortality (P = .03). CXCR7 was highly expressed in endothelial cells in high‐grade BCa tissues when compared to low‐grade BCa and normal bladder. CXCR7 levels were elevated in exfoliated urothelial cells from high‐grade BCa patients (P = .0001; 90% sensitivity; 75% specificity); CXCR4 levels were unaltered.CONCLUSIONS:CXCR7 promotes BCa cell proliferation and motility plausibly through epidermal growth factor receptor receptor and Akt signaling. CXCR7 expression is elevated in BCa tissues and exfoliated cells and is associated with high‐grade and metastasis. Cancer 2013. © 2012 American Cancer Society.
Number of primary melanomas is an independent predictor of survival in patients with metastatic melanoma
Authors: Murali Rajmohan , Brown Philip T. , Kefford Richard F. , Scolyer Richard A. , Thompson John F. , Atkins Michael B. , Long Georgina V. 
Published: June 2012

AbstractBACKGROUND:A history of multiple primary melanomas (PMs) has been associated with improved survival in patients with early stage melanoma, but whether it also is correlated with survival in patients with metastatic melanoma is unknown. The authors sought to address the latter question in the current study.METHODS:Patients with metastatic melanoma diagnosed at the Melanoma Institute Australia between 1983 and 2008 were identified. Overall survival (OS) was calculated from date of first distant metastasis. Survival analysis was performed using the Kaplan‐Meier method, log‐rank tests, and multivariate Cox proportional hazards models.RESULTS:Of 2942 patients with metastatic melanoma, 2634 (89.5%) had 1 PM and 308 (10.5%) had >1 PM. Factors that were associated independently with shorter OS were site of metastasis, including the brain (hazard ratio [HR], 2.41; 95% confidence interval [CI], 2.07‐2.81; P < .001) and nonlung viscera (HR, 1.92; 95% CI, 1.67‐2.22; P < .001, vs lymph node/subcutaneous/soft tissue), age >60 years (HR, 1.23; 95% CI, 1.12‐1.36; P < .001), shorter disease‐free interval from PM to first distant metastasis (≤12 months vs >36 months: HR, 1.62; 95% CI, 1.39‐1.89; P < .001), and fewer PMs (1 vs >1; HR, 1.26; 95% CI, 1.08‐1.47; P = .004).CONCLUSIONS:A history of multiple PM was an independent predictor of improved survival for patients with metastatic melanoma. The results indicate that a history of multiple PMs should be incorporated into multivariate analyses of prognostic factors and treatment outcomes. Cancer 2012. © 2012 American Cancer Society.
Enrichment of CD133‐expressing cells in rectal cancers treated with preoperative radiochemotherapy is an independent marker for metastasis and survival
Authors: Sprenger Thilo , Conradi Lena‐Christin , Beissbarth Tim , Ermert Heiko , Homayounfar Kia , Middel Peter , Rüschoff Josef , Wolff Hendrik A. , Schüler Philipp , Ghadimi B. Michael , Rödel Claus , Becker Heinz , Rödel Franz , Liersch Torsten 
Published: June 2012

AbstractBACKGROUND:The transmembrane glycoprotein CD133 (cluster of differentiation 133; also known as Prominin or PROM1) has been described as a potential stem cell marker in colorectal cancer and is associated with higher tumorigenic potential and resistance to radiochemotherapy (RCT). In this study, CD133 expression was evaluated in pre‐RCT tumor biopsies and the corresponding post‐RCT surgical specimens from patients with locally advanced rectal adenocarcinoma, and expression levels were correlated with histopathologic features and clinical follow‐up.METHODS:One hundred twenty‐six patients with International Union Against Cancer (UICC) stage II/III rectal cancer who received preoperative 5‐fluorouracil (5‐FU)‐based RCT within the German Rectal Cancer Trials were investigated. Pre‐RCT and post‐RCT CD133 expression levels were determined using immunohistochemistry and were correlated with histopathologic parameters, tumor regression grade, cancer recurrence, and patient survival.RESULTS:Compared with pre‐RCT biopsies, significantly higher CD133 expression was observed in tumor specimens (P = .01). However, no correlations were observed for either biopsies or tumor specimens between CD133 expression levels, histopathologic characteristics, or survival. In matched analyses of corresponding biopsy/tumor pairs, patients who had an increased fraction of CD133‐expressing (CD133+) cells after preoperative RCT had significantly higher residual tumor stages (P = .02) and lower histopathologic tumor regression (P < .01). Moreover, these patients had significantly reduced disease‐free survival and cancer‐specific overall survival in univariate analysis (P < .001 and P = .004, respectively) and multivariate analysis (P = .003 and P = .024, respectively).CONCLUSIONS:The enrichment of CD133+ cancer cells during preoperative RCT was correlated with minor local tumor response, increased distant cancer recurrence, and decreased survival. The current results indicate that the up‐regulation of intratumoral CD133 expression, in contrast to absolute pre‐RCT and post‐RCT CD133 levels, plays an important role in tumor progression and metastasis in patients with rectal cancer who are receiving neoadjuvant RCT. Cancer 2013. © 2012 American Cancer Society.
Calbindin expression in developing striatum of zebra finches and its relation to the formation of area X
Authors: Garcia‐Calero Elena , Scharff Constance 
Published: June 2012

AbstractA sexually dimorphic network of brain regions controls learning and production of song in zebra finches. How this specialized song system evolved is unknown. To start addressing this question, we focused on developmental differences between the sexes, using the expression of the calcium‐binding protein calbindin (CB) during embryonic to adult stages to map out the early development of Area X, a male‐specific striatal structure. We related this pattern to the expression of three transcription factors, Pax6 and Islet1 to delineate the striatal radial domains, and Nkx2.1 as a marker for cells of pallidal origin. An incipient Area X‐CB+ domain became discernable at embryonic day 13 in the Islet1‐ventral striatal field. This region contained many Nkx2.1‐expressing cells with a morphology characteristic of migrating cells. Eight days after hatching (PHD) CB staining clearly delineated Area X. Another CB+ structure formed around PHD5 at the subpallial/pallial boundary. We call it the CB+striatal capsule (CB‐StC) and discuss its relation with the previously described striatal capsule in vertebrates. The CB cell population in both Area X and CB‐StC, but not in the surrounding striatum, colocalized with the striatal medium spiny neurons (MSNs) marker, D1‐receptor associated signaling protein dopamine‐and‐cAMP‐regulated phosphoprotein of 32 kDa, DARPP32. In females, CB‐positive cells were also present in the rostral striatum but did not coalesce into an Area X‐like structure. We discuss possible reasons for CB expression in MSNs in songbirds and mammals, but not described in chicken striatum. J. Comp. Neurol. 521:326–341, 2013. © 2012 Wiley Periodicals, Inc.
Distribution of glycinergic neurons in the brain of glycine transporter‐2 transgenic Tg(glyt2:Gfp) adult zebrafish: Relationship to brain–spinal descending systems
Authors: Barreiro‐Iglesias Antón , Mysiak Karolina Sandra , Adrio Fátima , Rodicio María Celina , Becker Catherina G. , Becker Thomas , Anadón Ramón 
Published: June 2012

AbstractWe used a Tg(glyt2:gfp) transgenic zebrafish expressing the green fluorescent protein (GFP) under control of the glycine transporter 2 (GLYT2) regulatory sequences to study for the first time the glycinergic neurons in the brain of an adult teleost. We also performed in situ hybridization using a GLYT2 probe and glycine immunohistochemistry. This study was combined with biocytin tract tracing from the spinal cord to reveal descending glycinergic pathways. A few groups of GFP+/GLYT2− cells were observed in the midbrain and forebrain, including numerous pinealocytes. Conversely, a small nucleus of the midbrain tegmentum was GLYT2+ but GFP−. Most of the GFP+ and GLYT2+ neurons were observed in the rhombencephalon and spinal cord, and a portion of these cells showed double GLYT2/GFP labeling. In the hindbrain, GFP/GLYT2+ populations were observed in the medial octavolateral nucleus; the secondary, magnocellular, and descending octaval nuclei; the viscerosensory lobes; and reticular populations distributed from trigeminal to vagal levels. No glycinergic cells were observed in the cerebellum. Tract tracing revealed three conspicuous pairs of GFP/GLYT2+ reticular neurons projecting to the spinal cord. In the spinal cord, GFP/GLYT2+ cells were observed in the dorsal and ventral horns. GFP+ fibers were observed from the olfactory bulbs to the spinal cord, although their density varied among regions. The Mauthner neurons received very rich GFP+ innervation, mainly around the axon cap. Comparison of the zebrafish glycinergic system with the glycinergic systems of other adult vertebrates reveals shared patterns but also divergent traits in the evolution of this system. J. Comp. Neurol. 521:389–425, 2013. © 2012 Wiley Periodicals, Inc.