bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Ultrasensitive Fluorescent Sensing Nanofilm for Organic Amines Based on Cholesterol‐Modified Perylene Bisimide
Authors: Peng Haonan , Ding Liping , Liu Taihong , Chen Xiangli , Li Lan , Yin Shiwei , Fang Yu 
Published: April 2012

AbstractA stable, ultrasensitive, and fully reversible fluorescent sensing film for organic amines has been fabricated by assembling cholesterol (Chol)‐derived perylene bisimide on a glass plate surface. The compound exhibits excellent film formation properties and forms well‐defined nanofibers, as evidenced by SEM and AFM measurements. It has been revealed that besides the molecular structure of the specially designed perylene derivative, the existence of nanofibers in the film is another key factor to endow the film with superior sensing ability for organic amines, including aniline. The detection limit of the amine is ca. 150.0 ppt in the vapor phase and at room temperature. Furthermore, the sensing process is free of interference from common organic solvents, nitroaromatics, and particularly phenols, which makes the film a potential candidate to be used in lung cancer diagnoses and related applications.
Tridentate Thiolate Ligands: Application to the Synthesis of the Site‐Differentiated [4Fe‐4S] Cluster having a Hydrosulfide Ligand at the Unique Iron Center
Authors: Terada Tamaki , Wakimoto Takuya , Nakamura Tomohiko , Hirabayashi Kiyohisa , Tanaka Kaho , Li Jichun , Matsumoto Tsuyoshi , Tatsumi Kazuyuki 
Published: April 2012

AbstractWe have designed new trithiols Temp(SH)3 and Tefp(SH)3 that can be synthesized conveniently in short steps and are useful for preparation of crystalline [3:1] site‐differentiated [4Fe‐4S] clusters suitable for X‐ray structural analysis. The ethanethiolate clusters (PPh4)2[Fe4S4(SEt)(TempS3)] (4a) and (PPh4)2[Fe4S4(SEt)(TefpS3)] (4b) were prepared as precursors, and the unique iron sites were then selectively substituted. Upon reaction with H2S, (PPh4)2[Fe4S4(SH)(TempS3)] (6a) and (PPh4)2[Fe4S4(SH)(TefpS3)] (6b), which model the [4Fe‐4S] cluster in the β subunit of (R)‐2‐hydroxyisocaproyl‐CoA dehydratase, were synthesized. Clusters 6a and 6b were further converted to the sulfido‐bridged double cubanes (PPh4)4[{Fe4S4(TempS3)}2(μ2‐S)] (6b) and (PPh4)4[{Fe4S4(TefpS3)}2(μ2‐S)] (7b), respectively, via intermolecular condensation with the release of H2S. Conversely, addition of H2S to 7a, 7b afforded the hydrosulfide clusters 6a, 6b. The molecular structures of the clusters reported herein were elucidated by X‐ray crystallographic analysis. Their redox properties were investigated by cyclic voltammetry.
Dissecting the Maturation Steps of the Lasso Peptide Microcin J25 in vitro
Authors: Yan Kok‐Phen , Li Yanyan , Zirah Séverine , Goulard Christophe , Knappe Thomas A. , Marahiel Mohamed A. , Rebuffat Sylvie 
Published: April 2012

AbstractMicrocin J25 is the archetype of a growing class of bacterial ribosomal peptides possessing a knotted topology (lasso peptides). It consists of an eight‐residue macrolactam ring through which the C‐terminal tail is threaded. It is biosynthesized as a precursor that is processed by two maturation enzymes (McjB/McjC). Insights into the mechanism of microcin J25 biosynthesis have been provided previously by mutagenesis of the precursor peptide in vivo. In this study we have demonstrated distinct functions of McjB and McjC in vitro for the first time, based on the detection of reaction intermediates. McjB was characterized as a new ATP‐dependent cysteine protease, whereas McjC was confirmed to be a lactam synthetase. The two enzymes were functionally interdependent, likely forming a structural complex. Their substrate preference was directly investigated with the aid of mutated precursor peptides. Depending on the substitutions, microcin J25 variants with either a lasso or branched‐cyclic topology could be generated in vitro.
Optical coherence tomography evaluation of drug‐eluting stents
Authors: Papayannis Aristotelis C. , Cipher Daisha , Banerjee Subhash , Brilakis Emmanouil S. 
Published: April 2012

AimsWe performed a systematic review of studies reporting stent strut coverage and malapposition post implantation of different drug‐eluting stent (DES), as assessed by optical coherence tomography (OCT).MethodsA review of publications and online databases in May 2011 retrieved 33 published studies reporting stent strut coverage and malapposition post‐DES implantation using OCT: 24 for sirolimus‐eluting stents (SES), 13 for paclitaxel‐eluting stents (PES), 10 for zotarolimus‐eluting stents (ZES), and two for everolimus‐eluting stents (EES). The follow‐up duration ranged from 3 months to 4 years. Stent strut coverage and malapposition were compared between DES at various time intervals post implantation.ResultsSignificant differences in stent strut coverage and malapposition exist between various DES. The SES had the highest frequency of uncovered struts at 3, 6, 9, and 12 months (13.1%, 10.9%, 8.1%, and 7.5%, respectively), followed by PES (5.5%, 4.4%, and 5.7% at 6, 9, and 12 months, respectively) and ZES (0.7%, 0%, and 0.5% at 3, 6, and 9 months, respectively) (P < 0.001 for all comparisons between stents). Only two studies reported 3.1% uncovered struts at 9 months with the EES. Stent strut malapposition at 6, 9, and 12 months was highest with SES (3.2%, 2.2%, and 1.2%, respectively) followed by PES (1.6%, 1.3%, and 0.9%, respectively), EES (0.46% at 9 months), and ZES (0.7% and 0.1% at 6 and 9 months, respectively).ConclusionsSES had the highest rates of uncovered struts and malapposition, followed by PES and ZES. Such differences may explain the different clinical outcomes between various DES. © 2012 Wiley Periodicals, Inc.
Reversal of Anomeric Selectivity with O‐Glycosyl Trichloroacetimidates as Glycosyl Donors and Thiols as Acceptors Under Acid/Base Catalysis
Authors: Kumar Amit , Schmidt Richard R. 
Published: April 2012

AbstractBoron trifluoride or trimethylsilyl trifluoromethanesulfonate catalysed the generation of thioglycosides from O‐glucopyranosyl or O‐galactopyranosyl trichloroacetimidates and thiols giving mainly or exclusively α‐thioglycosides. However, the same reactions with phenylboron difluoride as catalyst are highly β‐selective. An SN2‐type reaction course under acid/base catalysis is invoked by these and previous results.
Upgrading biomass fast pyrolysis liquids
Authors: Bridgwater Anthony V. 
Published: April 2012

AbstractA comprehensive examination is made of the characteristics and quality requirements of bio‐oil from fast pyrolysis of biomass. An appreciation of the potential for bio‐oil to meet a broad spectrum of applications in renewable energy has led to a significantly increased R&D activity that has focused on addressing liquid quality issues both for direct use for heat and power and indirect use for biofuels and green chemicals. This increased activity is evident in North America, Europe, and Asia with many new entrants as well as expansion of existing activities. The only disappointment is the more limited industrial development and also deployment of fast pyrolysis processes that are necessary to provide the basic bio‐oil raw material. © 2012 American Institute of Chemical Engineers Environ Prog, 2012
Diagnosis of river basins as CO2sources or sinks subject to sediment movement
Authors: Yue Yao , Ni Jinren , Borthwick Alistair G. L. , Miao Chiyuan 
Published: April 2012

ABSTRACTSediment movement during erosion, transport and deposition greatly affects the ecosystem of river basins. However, there is presently no consensus as to whether particular river basins act as carbon dioxide (CO2) sources or sinks related to these processes. This paper introduces a rule‐of‐thumb coordinate system based on sediment delivery ratio (SDR) and soil humin content (SHC) in order to evaluate the net effect of soil erosion, sediment transport and deposition on CO2flux in river basins. The SDR–SHC system delineates CO2source and sink areas, and further divides the sink into strong and weak areas according to the world‐average line. The Yellow River Basin, most severely suffering soil erosion in the world, only appears to be a weak erosion‐induced CO2sink in this system. The average annual CO2sequestration is ~0·235 Mt from 1960 to 2008, a relatively small value considering its 3·1% contribution to the World's sediment discharge. The temporal analysis shows that the Yellow River Basin was once a source in the 1960s, but changed its role to become a weak sink in the past 40 years due to both anthropogenic and climatic influences. The spatial analysis identifies the middle sub‐basin as the main source region, and the lower as the main sink. For comparison, sediment‐movement‐related CO2fluxes of eight other major basins in four continents are examined. It is found that the six basins considered in the Northern Hemisphere appear to be sinks, while the other two in the Southern Hemisphere act as sources. Copyright © 2012 John Wiley & Sons, Ltd.
Balkas – a new look at a common landform of the East European Plain, from a Quaternary perspective
Authors: Matoshko Andrei V. 
Published: April 2012

ABSTRACTBalkas (large Quaternary gullies) of the south‐western part of the East European Plain (and their analogues in Central and Western Europe) are considered in terms of their geomorphology, lithology, sedimentology, modern surface processes, stratigraphy and palaeogeography. Features attributed to balkas in comparison with regular gullies and small river valleys are described. Balkas are widespread elements of the modern landscape with the same characteristic gentle‐concave bottom as regular gullies, and with or without weakly incised river channels. Buried gully incisions of different ages (post‐Gelasian) with the same shape are also revealed below modern Balkas. They are infilled by characteristic balka alluvial, slope and even lacustrine‐bog deposits, in places representing compound sequences of fluvial‐aeolian sedimentation. The fluvial part reflects multiple series of ephemeral episodes of increased water and sediment supply within temporary streams. Two conspicuous series supposedly fall within the final stages of the Dnieper (late Middle Pleistocene) and Valdai (Late Pleistocene) glaciations. Different ideas concerning the increase of surface runoff and erodibility of soils that might favour active balkas under conditions of land‐ice decay and permafrost, including its degradation, are discussed. The development of balkas included relatively short phases of incision and accumulation interrupted by much longer periods of inactivity, when they were subjected to surface processes in a subaerial environment or left as a relic. However, during active phases they served as important and powerful depositories and arteries of rill–gully–balka sedimentation systems, collecting and transmitting eroded material to the river valleys. These phases are related to climatic oscillations and were to some degree independent of fluvial processes affecting the permanent streams. Most of the Middle‐Late Pleistocene balkas retained their primary features, having subsequently been incorporated into the erosional network. In contrast, some of them were totally infilled and disappeared from the landscape. Copyright © 2012 John Wiley & Sons, Ltd.
Cadmium-induced changes in trace element bioaccumulation and proteomics perspective in four marine bivalves
Authors: Liu Fengjie , Wang Da-Zhi , Wang Wen-Xiong 
Published: April 2012

Abstract
Bivalves are employed widely as biomonitors of metal pollution and proteomics has increasingly been applied to solve ecotoxicological issues. This study aimed to investigate the effects of Cd exposure on the bioaccumulation of other trace elements and reveal the molecular mechanisms using proteomics technologies. The results showed that Cd exposure resulted in remarkable changes in body concentrations of Zn, Cu, Ag, Co, Ni, Pb, and Se in four marine bivalves (scallop Chlamys nobilis, clam Ruditapes philippinarum, mussel Perna viridis, and oyster Saccostrea cucullata). Generally, the bivalves exposed to higher Cd concentration accumulated higher concentrations of Zn, Cu, and Se, but a lower concentration of Co. The accumulation of Ag, Ni, and Pb was specific for different species. The data strongly suggest that the influences of one metal exposure on the bioaccumulation of other metals/metalloids need to be considered in interpreting body concentrations of the elements in the biomonitors. Cd exposure had little effect on bivalve proteomes, and the identified proteins were insufficient to explain the observed disruption of trace element metabolism. However, protein expression signatures composed of the altered proteins could distinguish the clams and the mussels with different body Cd levels. The strong up-regulation of galectin in Cd-exposed oysters indicated the protein as a novel biomarker in environmental monitoring. Environ. Toxicol. Chem. 2012;31:1292–1300. © 2012 SETAC
Toxicity of crude oil chemically dispersed in a wave tank to embryos of Atlantic herring (Clupea harengus)
Authors: Greer Colleen D. , Hodson Peter V. , Li Zhengkai , King Thomas , Lee Kenneth 
Published: April 2012

Abstract
Tests of crude oil toxicity to fish are often chronic, exposing embryos from fertilization to hatch to oil solutions prepared using standard mixing procedures. However, during oil spills, fish are not often exposed for long periods and the dynamic nature of the ocean is not easily replicated in the lab. Our objective was to determine if brief exposures of Atlantic herring (Clupea harengus) embryos to dispersed oil prepared by standard mixing procedures was as toxic as oil dispersed in a more realistic model system. Embryos were first exposed to chemically dispersed Alaska North Slope crude and Arabian light crude oil for 2.4 h to 14 d from fertilization to determine if exposure time affected toxicity. Toxicity increased with exposure time, but 2.4-h exposures at realistic concentrations of oil induced blue-sac disease and reduced the percentage of normal embryos at hatch; there was little difference in toxicity between the two oils. Secondly, oil was chemically dispersed in a wave tank to determine if the resultant oil solutions were as toxic to herring embryos as laboratory-derived dispersed oil using a single exposure period of 24 h. Samples taken 15 min postdispersion were more toxic than laboratory-prepared solutions, but samples taken at 5, 30, and 60 min postdispersion were less toxic. Overall, the laboratory- and wave tank-derived solutions of dispersed oil provided similar estimates of toxicity despite differences in the methods for preparing test solutions, suggesting that laboratory and wave tank data are a reliable basis for ecological risk assessments of spilled oil. Environ. Toxicol. Chem. 2012;31:1324–1333. © 2012 SETAC
Effects of leachate from tree leaves and grass litter on tadpoles
Authors: Earl Julia E. , Cohagen Kara E. , Semlitsch Raymond D. 
Published: April 2012

Abstract
Tree species composition can change as a result of succession, climate change, fire suppression, and invasive species. These changes clearly affect forests, but they can also affect aquatic ecosystems based on differences in the input quality of leaf litter, such as plant secondary compounds. These compounds vary in type and concentration depending on species and can be toxic to aquatic organisms. To examine toxic effects on Pseudacris maculata and Pseudacris crucifer tadpoles, we conducted 60-d laboratory experiments to compare leaf litter leachate from a dominant canopy species (red oak) and nonnative species (white pine) with an aquatic grass (prairie cordgrass) and plain water control. An additional experiment examined the effects of white pine on Bufo americanus, Hyla versicolor, and tannin concentrations in natural ponds. Compared with the control and grass, tree leaf extracts resulted in reduced tadpole survival. Leached compounds from pine reduced tadpole survival to 3 d or less. Tadpoles were able to metamorphose in significant numbers only from the two controls. The lowered survival with the red oak treatment might have been caused by lowered dissolved oxygen or high tannin concentrations. However, pine is known to have high concentrations of toxic monoterpenes, which should be investigated further. We found that tannin concentrations in natural ponds were much lower than the test concentrations, indicating that these results may represent worst-case scenarios or unrealistic concentrations. Environ. Toxicol. Chem. 2012; 31: 1511–1517. © 2012 SETAC
Reverse‐flow scapular osteocutaneous flap for head and neck reconstruction
Authors: Zevallos Jose P. , Urken Mark L. 
Published: April 2012

AbstractBackgroundThe scapular osteocutaneous flap can be used for the reconstruction of a variety of head and neck defects. In this study, we describe use of the reverse‐flow scapular osteocutaneous flap in the setting of a vessel‐depleted neck.Methods and ResultsA retrospective review of patients who underwent scapular osteocutaneous free flap reconstruction over a 5‐year period revealed 3 patients who underwent reverse‐flow osteocutaneous scapular flaps. Indications for surgery included a large recurrent desmoid tumor of the mandible, recurrent alveolar ridge carcinoma, and osteoradionecrosis. All patients had a history of neck dissection and radiotherapy. Exploration of the contralateral neck was required to identify recipient vessels in all cases. Arterial and venous anastomoses were performed to the distal end of the thoracodorsal artery and subscapular vein, respectively, and no vein grafts were required. There were no cases of flap failures or donor site complications.ConclusionThis series demonstrates the safety and efficacy of the reverse flow osteocutaneous flap for complex mandibular reconstruction in cases where recipient vessels are limited. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Prevalence of human papillomavirus and cervical intraepithelial neoplasia in China: A pooled analysis of 17 population‐based studies
Authors: Zhao Fang‐Hui , Lewkowitz Adam K. , Hu Shang‐Ying , Chen Feng , Li Long‐Yu , Zhang Qing‐Ming , Wu Rui‐Fang , Li Chang‐Qing , Wei Li‐Hui , Xu Ai‐Di , Zhang Wen‐Hua , Pan Qin‐Jing , Zhang Xun , Belinson Jerome L. , Sellors John W. , Smith Jennifer S. , Qiao You‐Lin , Franceschi Silvia 
Published: April 2012

AbstractHigh‐risk (HR) human papillomavirus (HPV) prevalence has been shown to correlate well with cervical cancer incidence rates. Our study aimed to estimate the prevalence of HR‐HPV and cervical intraepithelial neoplasia (CIN) in China and indirectly informs on the cervical cancer burden in the country. A total of 30,207 women from 17 population‐based studies throughout China were included. All women received HPV DNA testing (HC2, Qiagen, Gaithersburg, MD), visual inspection with acetic acid and liquid‐based cytology. Women positive for any test received colposcopy‐directed or four‐quadrant biopsies. A total of 29,579 women had HR‐HPV testing results, of whom 28,761 had biopsy confirmed (9,019, 31.4%) or assumed (19,742, 68.6%) final diagnosis. Overall crude HR‐HPV prevalence was 17.7%. HR‐HPV prevalence was similar in rural and urban areas but showed dips in different age groups: at age 25–29 (11.3%) in rural and at age 35–39 (11.3%) in urban women. In rural and urban women, age‐standardized CIN2 prevalence was 1.5% [95% confidence interval (CI): 1.4–1.6%] and 0.7% (95% CI: 0.7–0.8%) and CIN3+ prevalence was 1.2% (95% CI: 1.2–1.3%) and 0.6% (95% CI: 0.5–0.7%), respectively. Prevalence of CIN3+ as a percentage of either all women or HR‐HPV‐positive women steadily increased with age, peaking in 45‐ to 49‐year‐old women. High prevalence of HR‐HPV and CIN3+ was detected in both rural and urban China. The steady rise of CIN3+ up to the age group of 45–49 is attributable to lack of lesion removal through screening. Our findings document the inadequacy of current screening in China while indirectly raising the possibility that the cervical cancer burden in China is underreported.
MDM2 SNP285 does not antagonize the effect of SNP309 in lung cancer
Authors: Ryan Bríd M. , Calhoun Kara M. , Pine Sharon R. , Bowman Elise D. , Robles Ana I. , Ambs Stefan , Harris Curtis C. 
Published: April 2012

AbstractConflicting reports exist regarding the contribution of SNP309 in MDM2 to cancer risk. Recently, SNP285 was shown to act as an antagonist to SNP309 by overriding the effect of SNP309 on SP1‐mediated transcription. Moreover, SNP285 modified the relationship between SNP309 and risk of breast, ovarian and endometrial cancer. We assessed whether SNP285 confounded the effect of SNP309 in lung cancer in a cohort of 720 controls and 556 cases. Our cohort included both Caucasians and African Americans. Neither SNP309 nor SNP285 was associated with lung cancer risk or survival. In addition, removal of individuals who carried the variant C allele of SNP285 did not modify the association between SNP309 with either lung cancer risk or survival. Although an effect of SNP285 has been demonstrated in breast, ovarian and endometrial cancer, our findings do not support a role for this SNP in lung cancer and raise the possibility that the effect of SNP285 is restricted to cancers in women.
Cardiovascular medications in angiogenesis—How to avoid the sting in the tail
Authors: Ma Chenming , Wang Qing , Man Yicun , Kemmner Wolfgang 
Published: April 2012

AbstractCancer and cardiovascular disease are the leading causes of death worldwide. Cardiovascular medications have recently been found to have favorable effects also for the treatment of noncardiovascular diseases, including cancer. In this review, we use a reverse bedside‐to‐bench approach to investigate the effects of common cardiovascular medications on tumor angiogenesis and vascular angiogenesis. Aspirin seems to reduce the risk of developing cancer, particularly colon cancer. However, whether the protective influence of aspirin is due to antiangiogenesis effect is still unclear. β‐Blockers, which are normally used to reduce heart rate and prolong diastole, trigger an increase in stretch‐associated release of proangiogenic growth factors thereby inducing angiogenesis. However, according to other studies β‐blockers are able to inhibit angiogenesis via multiplicate mechanisms. Similarly, angiotensin converting enzyme inhibitor and angiotensin II type 1 receptor blocker have controversial effects for the regulation of cell proliferation and angiogenesis. Statins can augment collateral vascular growth in ischemic tissues and restrict the development of cancer. So this topical anti‐inflammatory drug seems to be of high value for further therapy. Finally, suggestions on how this pilot experience may guide the conduct of future preclinical investigations, and clinical trials are discussed.