bluuebunny/crossref_metadata_2025_split huggingface dataset:
From songs to synapses: Molecular mechanisms of birdsong memory
Authors: Moorman Sanne , Mello Claudio V. , Bolhuis Johan J. 
Published: March 2011

AbstractThere are remarkable behavioral, neural, and genetic similarities between the way songbirds learn to sing and human infants learn to speak. Furthermore, the brain regions involved in birdsong learning, perception, and production have been identified and characterized in detail. In particular, the caudal medial nidopallium (the avian analog of the mammalian auditory‐association cortex) has been found to contain the neural substrate of auditory memory, paving the way for analyses of the underlying molecular mechanisms. Recently, the zebra finch genome was sequenced, and annotated cDNA databases representing over 15,000 unique brain‐expressed genes are available, enabling high‐throughput gene expression analyses. Here we review the involvement of immediate early genes (e.g. zenk and arc), their downstream targets (e.g. synapsins), and their regulatory signaling pathways (e.g. MAPK/ERK) in songbird memory. We propose that in‐depth investigations of zenk‐ and ERK‐dependent cascades will help to further unravel the molecular basis of auditory memory.
Does constructive neutral evolution play an important role in the origin of cellular complexity?
Authors: Speijer Dave 
Published: March 2011

AbstractRecently, constructive neutral evolution has been touted as an important concept for the understanding of the emergence of cellular complexity. It has been invoked to help explain the development and retention of, amongst others, RNA splicing, RNA editing and ribosomal and mitochondrial respiratory chain complexity. The theory originated as a welcome explanation of isolated small scale cellular idiosyncrasies and as a reaction to ‘overselectionism’. Here I contend, that in its extended form, it has major conceptual problems, can not explain observed patterns of complex processes, is too easily dismissive of alternative selectionist models, underestimates the creative force of complexity as such, and – if seen as a major evolutionary mechanism for all organisms – could stifle further thought regarding the evolution of highly complex biological processes.
Intrinsic autotrophic biomass yield and productivity in algae: Modeling spectral and mixing‐rate dependence
Authors: Holland Alexandra D. , Wheeler Dean R. 
Published: March 2011

AbstractFor non‐inhibitory irradiances, the rate of algal biomass synthesis was modeled as the product of the algal autotrophic yield ΦDW and the flux of photons absorbed by the culture, as described using Beer‐Lambert law. As a contrast to earlier attempts, the use of scatter‐corrected extinction coefficients enabled the validation of such approach, which bypasses determination of photosynthesis‐irradiance (PI) kinetic parameters. The broad misconception that PI curves, or the equivalent use of specific growth rate expressions independent of the biomass concentration, can be extended to adequately model biomass production under light‐limitation is addressed. For inhibitory irradiances, a proposed mechanistic model, based on the photosynthetic units (PSU) concept, allows one to estimate a target speed νT across the photic zone in order to limit the flux of photons per cell to levels averting significant reductions in ΦDW. These modeled target speeds, on the order of 5–20 m s(1 for high outdoor irradiances, call for fundamental changes in reactor design to optimize biomass productivity. The presented analysis enables a straightforward bioreactor parameterization, which, in‐turn, guides the establishment of conditions ensuring maximum productivity and complete nutrients consumption. Additionally, solar and fluorescent lighting spectra were used to calculate energy to photon‐counts conversion factors.
Nitrogen starvation strategies and photobioreactor design for enhancing lipid content and lipid production of a newly isolated microalga Chlorella vulgaris ESP‐31: Implications for biofuels
Authors: Yeh Kuei‐Ling , Chang Jo‐Shu 
Published: March 2011

AbstractMicroalgae are recognized for serving as a sustainable source for biodiesel production. This study investigated the effect of nitrogen starvation strategies and photobioreactor design on the performance of lipid production and of CO2 fixation of an indigenous microalga Chlorella vulgaris ESP‐31. Comparison of single‐stage and two‐stage nitrogen starvation strategies shows that single‐stage cultivation on basal medium with low initial nitrogen source concentration (i.e., 0.313 g/L KNO3) was the most effective approach to enhance microalgal lipid production, attaining a lipid productivity of 78 mg/L/d and a lipid content of 55.9%. The lipid productivity of C. vulgaris ESP‐31 was further upgraded to 132.4 mg/L/d when it was grown in a vertical tubular photobioreactor with a high surface to volume ratio of 109.3 m2/m3. The high lipid productivity was also accompanied by fixation of 6.36 g CO2 during the 10‐day photoautotrophic growth with a CO2 fixation rate of 430 mg/L/d. Analysis of fatty acid composition of the microalgal lipid indicates that over 65% of fatty acids in the microalgal lipid are saturated [i.e., palmitic acid (C16:0) and stearic acid (C18:0)] and monounsaturated [i.e., oleic acid (C18:1)]. This lipid quality is suitable for biodiesel production.
Integration of biomolecules and nanomaterials: Towards highly selective and sensitive biosensors
Authors: Hyun Seok  , Park Tai Hyun 
Published: March 2011

AbstractSignificant efforts have been made toward the development of high‐performance biosensors for various applications. Advances in nanotechnology have resulted in the development of highly sensitive electrochemical sensing devices. It is believed that highly sensitive and selective biosensors can be realized through the integration of biomolecules and nanomaterial‐based sensor platforms. Numerous articles have described combining biomolecules as recognition elements with nanotechnology for the development of biosensors with enhanced selectivity and sensitivity. Recent advances in the development of biosensors through the integration of biomolecules with nanotechnology are reviewed in this article.
Mitochondria induce oxidative stress, generation of reactive oxygen species and redox state unbalance of the eye lens leading to human cataract formation: disruption of redox lens organization by phospholipid hydroperoxides as a common basis for cataract disease
Authors: Babizhayev Mark A. 
Published: March 2011

AbstractThe aging eye appears to be at considerable risk from oxidative stress. Lipid peroxidation (LPO) is one of the mechanisms of cataractogenesis, initiated by enhanced promotion of oxygen free radicals in the eye fluids and tissues and impaired enzymatic and non‐enzymatic antioxidant defenses of the crystalline lens. The present study proposes that mitochondria are one of the major sources of reactive oxygen species (ROS) in mammalian and human lens epithelial cells and that therapies that protect mitochondria in lens epithelial cells from damage and reduce damaging ROS generation may potentially ameliorate the effects of free radical‐induced oxidation that occur in aging ocular tissues and in human cataract diseases. It has been found that rather than complete removal of oxidants by the high levels of protective enzyme activities such as superoxide dismutase (SOD), catalase, lipid peroxidases in transparent lenses, the lens conversely, possess a balance between peroxidants and antioxidants in a way that normal lens tends to generate oxidants diffusing from lenticular tissues, shifting the redox status of the lens to become more oxidizing during both morphogenesis and aging. Release of the oxidants (O, H2O2, OH., and lipid hydroperoxides) by the intact lenses in the absence of respiratory inhibitors indicates that these metabolites are normal physiological products inversely related to the lens life‐span potential (maturity of cataract) generated through the metal‐ion catalyzed redox‐coupled pro‐oxidant activation of the lens reductants (ascorbic acid, glutathione). The membrane‐bound phospholipid (PL) hydroperoxides escape detoxification by the lens enzymatic reduction. The lens cells containing these species would be vulnerable to peroxidative attack which trigger the PL hydroperoxide‐dependent chain propagation of LPO and other damages in membrane (lipid and protein alterations). The increased concentrations of primary LPO products (diene conjugates, lipid hydroperoxides) and end fluorescent LPO products were detected in the lipid moiety of the aqueous humor samples obtained from patients with cataract as compared to normal donors. Since LPO is clinically important in many of the pathological effects and aging, new therapeutic modalities, such as patented N‐acetylcarnosine prodrug lubricant eye drops, should treat the incessant infliction of damage to the lens cells and biomolecules by reactive lipid peroxides and oxygen species and “refashion” the affected lens membranes in the lack of important metabolic detoxification of PL peroxides. Combined in ophthalmic formulations with N‐acetylcarnosine, mitochondria‐targeted antioxidants are promising to become investigated as a potential tool for treating a number of ROS‐related ocular diseases, including human cataracts. Copyright © 2011 John Wiley & Sons, Ltd.
Low‐temperature CH4 Catalytic Combustion over Pd Catalyst Supported on Co3O4 Nanocrystals with Well‐Defined Crystal Planes
Authors: Hu Linhua , Peng Qing , Li Yadong 
Published: March 2011

AbstractWe report a novel strategy to prepare supported Pd catalysts for low‐temperature methane combustion. The structure–property relationship of the catalysts was investigated by tuning the shape and crystal planes of supporting Co3O4 nanocrystals. Pd/Co3O4 nanosheets are more reactive than Pd/Co3O4 nanobelts and nanocubes with the same Pd loading. The strong surface interaction between the Co3O4 unit cell and the PdO unit cell on {112} crystal plane of Pd/Co3O4 nanosheets has been analyzed by using high resolution transmission electron microscopy and temperature programmed reduction experiments.
Self‐Assembled 3D Flowerlike Hierarchical Fe3O4@Bi2O3 Core–Shell Architectures and Their Enhanced Photocatalytic Activity under Visible Light
Authors: Wang Yang , Li Shikuo , Xing Xianran , Huang Fangzhi , Shen Yuhua , Xie Anjian , Wang Xiufang , Zhang Jian 
Published: March 2011

AbstractThree‐dimensional (3D) flowerlike hierarchical Fe3O4@Bi2O3 core–shell architectures were synthesized by a simple and direct solvothermal route without any linker shell. The results indicated that the size of the 3D flowerlike hierarchical microspheres was about 420 nm and the shell was composed of several nanosheets with a thickness of 4–10 nm and a width of 100–140 nm. The saturation magnetization of the superparamagnetic composite microspheres was about 41 emu g−1 at room temperature. Moreover, the Fe3O4@Bi2O3 composite microspheres showed much higher (7–10 times) photocatalytic activity than commercial Bi2O3 particles under visible‐light irradiation. The possible formation mechanism was proposed for Ostwald ripening and the self‐assembled process. This novel composite material may have potential applications in water treatment, degradation of dye pollutants, and environmental cleaning, for example.
Conformations of Spermine in Adenosine Triphosphate Complex: The Structural Basis for Weak Bimolecular Interactions of Major Cellular Electrolytes
Authors: Maruyoshi Keisuke , Yamaguchi Toshiyuki , Demura Tetsuo , Matsumori Nobuaki , Oishi Tohru , Murata Michio 
Published: March 2011

AbstractSelectively 2H‐ and 13C‐labeled spermines (SPM) were efficiently synthesized and analyzed by NMR spectroscopy to determine the spin–spin coupling constants for six conformationally relevant bonds. SPM that is composed of three alkyl moieties, a butanylene, and two propanylene chains undergoes a conformational change when interacting with multivalent anions (e.g., adenosine triphosphate (ATP), ATP–Mg2+, and tripolyphosphate). Upon interaction with ATP, the CC bonds, which affect the distance between the neighboring pairs of ammonium groups (i.e., N1/N5 and N5/N5′), increase the population of gauche rotamers by 17–20 % relative to those in the 4 HCl salt of SPM. However, the trend in increments of the gauche conformers for the SPM–ATP complex profoundly differs from that of the spermidine (SPD)–ATP complex. This implies that SPM may preferentially recognize the adenyl group of ATP rather than the tripolyphosphate moiety. This may account for the higher affinity of SPM to ATP–Mg2+ than with that of SPD, which chiefly interacts with β‐ and γ‐phosphates and is easily replaced by Mg2+. These results may provide a clue for the further understanding of the structural basis of polyamine biological functions.
A Novel and Convenient Synthesis of Benzonitriles: Electrophilic Cyanation of Aryl and Heteroaryl Bromides
Authors: Anbarasan Pazhamalai , Neumann Helfried , Beller Matthias 
Published: March 2011

AbstractN‐Cyano‐N‐phenyl‐p‐methylbenzenesulfonamide has been used as a more benign electrophilic cyanation reagent for the synthesis of various benzonitriles from (hetero)aryl bromides via formation of Grignard reagents. Electronically different and sterically demanding aryl bromides including functionalized substrates and heteroaryl bromides are successfully cyanated in good to excellent yields. The efficiency of the present methodology is shown by the expeditious syntheses of interesting pharmaceutical intermediates. Notably, chemoselective monocyanation of dibromoarenes is also achieved.
Synthesis, Structure, and Reactivity of a Pyridine‐Stabilized Germanone
Authors: Yao Shenglai , Xiong Yun , Wang Wenyuan , Driess Matthias 
Published: March 2011

AbstractThe first isolable pyridine‐stabilized germanone has been prepared and its reactivity toward trimethylaluminum has been investigated. The germanone adduct results from a stepwise conversion that starts from 4‐dimethylaminopyridine (DMAP) and the ylide‐like N‐heterocyclic germylene LGe: (L=CH{(CCH2)(CMe)[N(aryl)]2}, aryl=2,6‐iPr2C6H3) (1) at room temperature, and gives the corresponding germylene–pyridine adduct L(DMAP)Ge: (2) in 91 % yield. The latter reacts with N2O at room temperature to form the desired germanone complex L(DMAP)GeO (3) in 73 % yield. The GeO distance of 1.646(2) Å in 3 is the shortest hitherto reported for a GeO species. The reaction of 3 with trimethylaluminum leads solely to the addition product LGe(Me)O[Al(DMAP)Me2] (4). The latter results from insertion of the GeO subunit into an AlMe bond of AlMe3 and concomitant migration of the DMAP ligand from germanium to the aluminum atom. Compounds 2–4 have been fully characterized by analytical and spectroscopic methods. Their molecular structures have been established by single‐crystal X‐ray crystallographic analysis.
Stereoselective degradation of diclofop‐methyl during alcohol fermentation process
Authors: Lu Yuele , Diao Jinling , Gu Xu , Zhang Yanfeng , Xu Peng , Wang Peng , Zhou Zhiqiang 
Published: March 2011

AbstractStereoselective degradation of Diclofop‐methyl (DM) has been found in alcohol fermentation of grape must and sucrose solution with dry yeast. A method was developed for separation and determination the two enantiomers of DM during the fermentation process by high‐performance liquid chromatography based on cellulose tri‐(3,5‐dimethylphenyl‐carbamate) chiral stationary phase. The results showed that the enantiomers of DM degraded following the first‐order kinetics in the sucrose solution and the degradation of DM enantiomers in grape must were biphasic (slow‐fast‐slow process). In the sucrose solution, half lives of (+)‐(R)‐DM and (−)‐(S)‐DM were calculated to be 8.5 h and 3.1 h, respectively. In the grape must, half life of (+)‐(R)‐DM was calculated to be 41.7 h while (−)‐(S)‐DM was 16.0 h. The result was that (−)‐(S)‐enantiomer degraded faster than the (+)‐(R)‐enantiomer in both alcohol fermentation. The results also showed that the differences of the enantioselective degradation of DM depended on the fermentation matrix. DM was configurationally stable in fermentation, showing no interconversion of (−)‐(S)‐ to (+)‐(R)‐ enantiomer, and vice‐versa. Chirality, 2011. © 2011 Wiley‐Liss, Inc.
Stochastic Modeling of Particle Formation in Fluidized Beds
Authors: Dernedde Mathias , Peglow Mirko , Tsotsas Evangelos 
Published: March 2011

AbstractDie vorliegende Studie präsentiert die Anwendung einer stochastischen Lösungsmethode zur Populationsbilanzierung in Wirbelschicht‐Sprühagglomerationsprozessen. Die Monte‐Carlo‐Methode wird dabei als spezielles Lösungsverfahren genutzt, um eine diskrete Partikelprobe unter dem Einfluss von wirkenden Mikroprozessen im realen Prozess zu entwickeln. Besonderes Augenmerk wird auf die beispielhafte Beschreibung eines ausgewählten Mikroprozesses gelegt: der Vortrocknung von Tropfen zwischen Düse und Wirbelschicht.
Racial disparities and socioeconomic status in men diagnosed with testicular germ cell tumors
Authors: Sun Maxine , Abdollah Firas , Liberman Daniel , Abdo Al'a , Thuret Rodolphe , Tian Zhe , Shariat Shahrokh F. , Montorsi Francesco , Perrotte Paul , Karakiewicz Pierre I. 
Published: March 2011

AbstractBACKGROUND:Previous reports indicated that African‐American men with testicular germ cell tumors (TGCTs) have more aggressive tumor characteristics and less favorable outcomes than other men. The authors of this report evaluated the effects of race and socioeconomic status (SES) on stage distribution, overall mortality (OM), and cancer‐specific mortality (CSM) in men with TGCTs.METHODS:The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 22,553 men who were diagnosed with TGCTs between 1988 and 2006. Kaplan‐Meier and Cox regression analyses were generated to predict OM and CSM. Covariates of the analyses included race, SES, age, histologic subtype, disease stage, procedure type, SEER registry, and year of diagnosis. The interaction between race and SES also was examined.RESULTS:Overall, there were 516 African‐American men, 21,090 Caucasian men, and 947 men of other races. African‐Americans (14.9%) and individuals with low SES (10.7%) had a higher proportion of distant stage disease. CSM and OM rates were significantly higher for African‐American patients and for patients who resided in low SES counties. Multivariate analyses revealed that African‐American men and men with low SES were more likely to die of OM and CSM relative to Caucasian men (P < .001) and men with high SES (P < .001), respectively. The interaction between race and SES was not significant.CONCLUSIONS:African‐American race and low SES appeared to predispose men to more advanced disease stages and to higher OM and CSM rates. These observations may warrant race‐specific and/or SES‐specific adjustments in the treatment of TGCT. Cancer 2011;. © 2011 American Cancer Society.
Diagnostic yield of percutaneous image‐guided tissue biopsy of focal hepatic lesions in cancer patients
Authors: Elsayes Khaled M. , Ellis James H. , Elkhouly Tohamy , Ream Justin M. , Bowerson Michyla , Khan Asra , Caoili Elaine M. 
Published: March 2011

AbstractBACKGROUND:The diagnostic yield was evaluated of percutaneous image‐guided tissue biopsy of hepatic lesions identified on computed tomography performed for staging of a primary malignancy, and it was determined how often the biopsy result was unexpectedly negative, benign, or secondary to a second unknown malignancy.METHODS:In a retrospective investigation from 1998 through 2008, 580 patients with primary malignancies had indeterminate focal hepatic lesions and underwent percutaneous image‐guided biopsy; 369 patients had lesions in their liver at first cross‐sectional imaging, performed for staging; 211 patients had a negative liver imaging study, followed by the subsequent appearance of at least 1 indeterminate suspicious lesion. The results of percutaneous image‐guided tissue biopsies were compared with the histology of the primary malignancy.RESULTS:Liver biopsies were performed in 580 patients (288 men and 292 women; age, 25‐92 years; mean age, 61 years). The most common primary malignancies were pancreatic (n = 96), breast (n = 85), melanoma (n = 57), esophageal (n = 51), lung (n = 47), colorectal (n = 37), and urothelial tumors (n = 26). Biopsy results were positive for malignancy in 528 (91%) cases. Among the positive biopsies, 29 (5%) cases had pathology results different from the primary tumor. Of the 52 biopsies negative for malignancy, 20 yielded a specific benign diagnosis, and 32 were nondiagnostic.CONCLUSIONS:If all liver lesions had been assumed to be metastases, as expected secondary to the known primary tumor, then the true or presumed alternate diagnosis would have been missed in 60 (10.3%) of the 580 cases. The authors did not attempt to determine whether actual clinical management changed based on these 60 liver biopsy results, so this number is an upper bound on management change. On the basis of these results, and given the minimal complication rate of liver biopsy, the authors suggest that liver biopsy should still be performed in the types of cases studied here, despite the finding that the vast majority of biopsies produced the expected result and presumably did not change patient management. Cancer 2011;. © 2011 American Cancer Society.
Response, survival, and toxicity after iodine‐131–metaiodobenzylguanidine therapy for neuroblastoma in preadolescents, adolescents, and adults
Authors: Polishchuk Alexei L. , DuBois Steven G. , Haas‐Kogan Daphne , Hawkins Randall , Matthay Katherine K. 
Published: March 2011

AbstractBACKGROUND:Adolescent and adult patients with neuroblastoma appear to have a more indolent disease course but a lower survival rate compared with their younger counterparts. The majority of neuroblastoma tumors specifically accumulate the radiolabeled norepinephrine analogue iodine‐131–metaiodobenzylguanidine (131I‐MIBG). Therefore, 131I‐MIBG has become increasingly used as targeted radiotherapy for patients with recurrent or refractory neuroblastoma. The objective of the current study was to characterize the toxicity and activity of this therapy in older patients.METHODS:The authors performed a retrospective analysis of 39 consecutive patients aged ≥10 years with recurrent or refractory neuroblastoma who were treated with 131I‐MIBG monotherapy at the University of California at San Francisco under phase 1, phase 2, and compassionate access protocols.RESULTS:Sixteen patients were aged ≥18 years at the time of MIBG treatment initiation, whereas 23 patients were ages 10 to 17 years. The median cumulative administered dose of 131I‐MIBG was 17.8 millicuries (mCi)/kg. The majority of treatments led to grade 3 or 4 hematologic toxicities (graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 3]) that were similar in frequency among age strata. Three patients subsequently developed a hematologic malignancy or myelodysplasia. The overall rate of complete plus partial response was 46%. Patients aged ≥18 years at the time of first MIBG treatment had a significantly higher response rate compared with patients ages 10 to 17 years (56% vs 39%; P = .023). The median overall survival was 23 months with a trend toward longer overall survival for the subgroup of patients aged ≥18 years (P = .12).CONCLUSIONS:The findings of the current study suggest that 131I‐MIBG is a highly effective salvage agent for adolescents and adults with neuroblastoma. Cancer 2011;. © 2011 American Cancer Society.