bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial Distribution of Fe, Cu, Mn in the Surface Water System and Their Effects on Wetland Vegetation in the Pearl River Estuary of China
Authors: Huang Laibin , Bai Junhong , Xiao Rong , Gao Haifeng , Liu Peipei 
Published: September 2012

AbstractWater samples and vegetation data in 1 m × 1 m vegetation quads (vegetation density, biomass, and size were investigated) were collected from Panyu District and reclaimed regions with different reclamation histories in Nansha District throughout the Pearl River Estuary in August 2010. The spatial distribution characteristics of Fe, Cu, and Mn in the surface water system were measured based on ordinary Kriging method of ArcGis Geostatistical Analyst. Metal index (MI) was selected to assess the pollution levels and principal correlation analysis (PCA) was chose to interpret the effects of these heavy metals on vegetation. Results showed that (i) there were higher concentrations of Fe and Cu appearing in the up west than that in the other parts of the whole region, meanwhile, a similar spatial distribution was showed in Fe and Cu, which indicated the two kinds of metals came from the same pollution source; (ii) all the MI values exceeded class I level and the water quality in metal levels was over or equal to class III level in the whole research region, and worse water quality was presented in the middle west of Panyu District and in the old reclamation region in Nansha District due to the characteristic of the surface water system and the long‐term tillage, respectively; (iii) the concentrations of Fe and Cu showed negative correlation with vegetation, and Mn nearly had no effects on vegetations, and 1/3 of all samples were seated in the higher coverage and lower pollution area, which belongs to the new reclamation in Nansha District.
Implementation of Diversified Ecological Networks to Strengthen Wetland Conservation
Authors: Cui Baoshan , Zhang Zhiming , Lei Xiaoxia 
Published: September 2012

AbstractThe notion that the conservation of wetlands in the world is too limited has gained a universal consensus because of the conflicts between their great value and the drastic decline in their quantity and quality. To mitigate these conflicts, ecological networks have integrated the hydrologic and biological connectivity of ecosystems. The basic elements of ecological networks, patches, and corridors, have been extracted to reflect the attributes of the hydrologic and biological connectivity of ecosystems. This paper reviews recent applications of network approaches to ecological conservation, focusing on their application in wetland ecosystems, and proposing a new perspective for wetland conservation. This review is limited to four aspects: first, the linkages between wetlands and ecological networks are determined by reviewing the development both of them; second, the two types of connectivity and their application that can be obtained from graphs or network models are discussed; third, common network analysis approaches, which can provide a theoretical basis to explore the optimal relationship between network structure and function, are summarized; finally, this paper presents the configuration and convergence characteristics of different types of wetland networks at multiple spatial scales. At the conclusion, suggestions for further work are presented.
Effects of Water Level and Salinity on TN and TP Contents in Marsh Soils of the Yellow River Delta, China
Authors: Liu Peipei , Bai Junhong , Ding Qiuyi , Shao Hongbo , Gao Haifeng , Xiao Rong 
Published: September 2012

AbstractA field experiment was carried out at three different water levels and four salinity levels to study the effects of water level and salinity on nutrient contents in mash soil of the Yellow River Delta, China. Contents of total nitrogen (TN) and total phosphorus (TP) in surface and subsurface soils were measured under different water and salinity levels during the study period. Results showed that TN contents gradually decreased with increasing salinities and the highest content appeared in surface soils in different sampling dates. Higher TN contents in August (361.55 mg/kg) and September (412.17 mg/kg) were observed under 0.52 and 16.7‰ salinity treatments, respectively, and 10 cm water level, and the highest value in October (504.81 mg/kg) was observed under 10.2‰ salinity treatment and 0 cm water level. TN contents showed significant differences among different water treatments. Similarly, TP content also appeared an accumulation in surface soils in each sampling date. However, significant differences of TP contents in subsurface soils were observed among three water levels. Salinity significantly influenced the changes in TN and TP contents in both soil layers under different water level treatments. Soil TN and TP contents were significantly correlated to soil organic matter.
Spatial and Temporal Distributions of Soil Organic Carbon and Total Nitrogen in Two Marsh Wetlands with Different Flooding Frequencies of the Yellow River Delta, China
Authors: Bai Junhong , Wang Junjing , Yan Denghua , Gao Haifeng , Xiao Rong , Shao Hongbo , Ding Qiuyi 
Published: September 2012

AbstractA field study was carried out in two typical marsh wetlands (Sites A and B) with different flooding frequencies in the Yellow River Delta of China in three different dates to investigate spatial and temporal distributions of soil organic carbon (SOC) and total nitrogen (TN) along the distance away from one tidal creek and the Yellow River, respectively. The results showed that SOC and TN contents and densities generally decreased with depth, except for an obvious accumulation peak of TN at the 20–40 cm soil layer; and they had higher heterogeneity at both Sites A and B; However, SOC and TN contents and densities showed different spatial distribution patterns at both sites in different sampling dates. Generally, SOC and TN contents in marsh soils were higher at Site A than those at Site B. TN was significantly correlated with available phosphorous, SOC, and the carbon/nitrogen (C/N) ratio at both sites, whereas SOC was significantly correlated with soil depth, soil moisture and salinity at both sites. Additionally, the C/N ratios were higher at Site B than those at Site A, and they were significantly correlated with soil moisture (Site A), bulk density, and TN (Sites A and B).
Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs
Authors: García‐Moreno Inmaculada , Wang Lu , Costela Angel , Bañuelos Jorge , López Arbeloa Iñigo , Xiao Yi 
Published: September 2012

AbstractHerein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.
A fully integrated, highly linear CMOS T/R switch for X‐Band phased array radars
Authors: Dinc Tolga , Zihir Samet , Gurbuz Yasar 
Published: September 2012

AbstractThis paper presents the design and implementation of a single‐pole, double‐throw transmit/receive (T/R) switch for X‐Band (8–12 GHz) phased array radar applications. The T/R switch was fabricated in a 0.25‐µm SiGe BiCMOS process and occupies 0.44‐mm2 chip area, including pads. The design focuses on the techniques, primarily, to achieve higher power handling capability (P1dB), along with higher isolation and better insertion loss (IL) of the T/R switch. These techniques include resistive‐body floating, using on‐chip impedance transformation networks and DC biasing of all terminals of the T/R switch. In addition, optimization of transistor widths and parallel resonance technique are used to improve IL and isolation, respectively. All these design techniques resulted in a measured IL of 3.6 dB, isolation of 34.8 dB and IP1dB of 28.2 dBm at 10 GHz. The return losses at both input and output ports are better than 16 dB from 8 to 12 GHz. To our knowledge, this paper presents the single‐ended CMOS T/R switch with the highest IP1dB, competitive isolation and comparable IL at X‐Band, compared to other reported works in the literature and attributed to the unique design methodologies and techniques. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of E2F target genes that are rate limiting for dE2F1‐dependent cell proliferation
Authors: Herr Anabel , Longworth Michelle , Ji Jun‐Yuan , Korenjak Michael , MacAlpine David M. , Dyson Nicholas J. 
Published: September 2012

AbstractBackground: Microarray studies have shown that the E2F transcription factor influences the expression of many genes but it is unclear how many of these targets are important for E2F‐mediated control of cell proliferation. Results: We assembled a collection of mutant alleles of 44 dE2F1‐dependent genes and tested whether these could modify visible phenotypes caused by the tissue‐specific depletion of dE2F1. More than half of the mutant alleles dominantly enhanced de2f1‐dsRNA phenotypes suggesting that the in vivo functions of dE2F1 can be limited by the reduction in the level of expression of many different targets. Unexpectedly, several mutant alleles suppressed de2f1‐dsRNA phenotypes. One of the strongest of these suppressors was Orc5. Depletion of ORC5 increased proliferation in cells with reduced dE2F1 and specifically elevated the expression of dE2F1‐regulated genes. Importantly, these effects were independent of dE2F1 protein levels, suggesting that reducing the level of ORC5 did not interfere with the general targeting of dE2F1. Conclusions: We propose that the interaction between ORC5 and dE2F1 may reflect a feedback mechanism between replication initiation proteins and dE2F1 that ensures that proliferating cells maintain a robust level of replication proteins for the next cell cycle. Developmental Dynamics 241:1695–1707, 2012. © 2012 Wiley Periodicals, Inc.
Epigenetic landscape and miRNA involvement during neural crest development
Authors: Strobl‐Mazzulla Pablo H. , Marini Melisa , Buzzi Ailín 
Published: September 2012

AbstractThe neural crest (NC) is a multipotent, migratory cell population that arises from the dorsal neural fold of vertebrate embryos. NC cells migrate extensively and differentiate into a variety of tissues, including melanocytes, bone, and cartilage of the craniofacial skeleton, peripheral and enteric neurons, glia, and smooth muscle and endocrine cells. For several years, the gene regulatory network that orchestrates NC cells development has been extensively studied. However, we have recently begun to understand that epigenetic and posttranscriptional regulation, such as miRNAs, plays important roles in NC development. In this review, we focused on some of the most recent findings on chromatin‐dependent mechanisms and miRNAs regulation during vertebrate NC cells development. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc.
Membrane β‐catenin and adherens junctions in early gonadal patterning
Authors: Fleming Alice , Ghahramani Negar , Zhu Maggie Xiaoming , Délot Emmanuèle C. , Vilain Eric 
Published: September 2012

AbstractBackground: Mechanisms involved in early patterning of the mammalian gonad as it develops from a bipotential state into a testis or an ovary are as yet not well understood. Sex‐specific vascularization is essential in this process, but more specific mechanisms required to, for example, establish interstitial vs. cord compartments in the testis or ovigerous cords in the ovary have not been reported. Adherens junctions (AJs) are known for their roles in morphogenesis; we, therefore, examined expression of AJ components including β‐catenin, p120 catenin, and cadherins for possible involvement in sex‐specific patterning of the gonad. Results: We show that, at the time of early gonadal sex differentiation, membrane‐associated β‐catenin and p120 catenin colocalize with cell‐specific cadherins in both sex‐nonspecific and sex‐specific patterns. These expression patterns are consistent with an influence of AJs in overall patterning of the testis vs. ovary through known AJ mechanisms of cell–cell adhesion, cell sorting, and boundary formation. Conclusions: Together these complex and dynamic patterns of AJ component expression precisely mirror patterning of tissues during gonadogenesis and raise the possibility that AJs are essential effectors of patterning within the developing testis and ovary. Developmental Dynamics 241:1782–1798, 2012. © 2012 Wiley Periodicals, Inc.
Multiple layers of complexity in cis‐regulatory regions of developmental genes
Authors: Frankel Nicolás 
Published: September 2012

AbstractGenomes contain the necessary information to ensure that genes are expressed in the right place, at the right time, and with the proper rate. Metazoan developmental genes often possess long stretches of DNA flanking their coding sequences and/or large introns which contain elements that influence gene expression. Most of these regulatory elements are relatively small and can be studied in isolation. For example, transcriptional enhancers, the elements that generate the expression pattern of a gene, have been traditionally studied with reporter constructs in transgenic animals. These studies have provided and will provide invaluable insights into enhancer evolution and function. However, this experimental approach has its limits; often, enhancer elements do not faithfully recapitulate native expression patterns. This fact suggests that additional information in cis‐regulatory regions modulates the activity of enhancers and other regulatory elements. Indeed, recent studies have revealed novel functional aspects at the level of whole cis‐regulatory regions. First, the discovery of “shadow enhancers.” Second, the ubiquitous interactions between cis‐regulatory elements. Third, the notion that some cis‐regulatory regions may not function in a modular manner. Last, the effect of chromatin conformation on cis‐regulatory activity. In this article, I describe these recent findings and discuss open questions in the field. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc.
Computational Insight into the Mechanism of Selective Imine Formation from Alcohol and Amine Catalyzed by the Ruthenium(II)‐PNP Pincer Complex
Authors: Li Haixia , Wang Xiaotai , Wen Mingwei , Wang Zhi‐Xiang 
Published: September 2012

AbstractWe have used density functional theory computations to investigate the mechanism of the reaction of an amine with a primary alcohol catalyzed by the ruthenium(II)‐PNP pincer complex [PNP = 2,6‐bis(di‐tert‐butylphosphanylmethyl)pyridine]; the reaction produces an imine as the major product. The catalytic cycle includes four stages: (stage I) alcohol dehydrogenation to aldehyde, (stage II) coupling of aldehyde with amine to form hemiaminal, (stage III) hemiaminal dehydration to give imine, and (stage IV) catalyst regeneration by means of H2 elimination of the trans ruthenium dihydride complex produced in stage I. The mechanism is similar to that for amide formation from amine and alcohol that was catalyzed by the RuII‐PNN pincer complex [PNN = 2‐(di‐tert‐butylphosphanylmethyl)‐6‐(diethylaminomethyl)pyridine], the only difference being in stage III. Alcohol dehydrogenation (stage I) occurs by a bifunctional double hydrogen transfer mechanism and alcohol can facilitate stages II and III. The selectivity of imine over ester is governed by stage II: the formation of hemiaminal by means of aldehydeamine coupling is kinetically much more favorable than the alternative aldehydealcohol coupling reaction that yields hemiacetal. Furthermore, the hemiaminal dehydration to give an imine is also kinetically more favorable than the hemiacetal dehydrogenation to give an ester. The selectivity of imine over amide is determined by stage III: the hemiaminal dehydration to give an imine is kinetically much more favorable than the hemiaminal dehydrogenation to give an amide. The essential difference between the RuII‐PNP‐catalyzed imine synthesis and the RuII‐PNN‐catalyzed amide formation is that the former prefers hemiaminal dehydration whereas the latter prefers hemiaminal dehydrogenation. In addition, water produced during hemiaminal dehydration can catalyze stages II and III more effectively than alcohol can. By contrast, the water‐catalyzed hemiaminal formation does not happen in the RuII‐PNN‐catalyzed synthesis of an amide because no water is produced in any stage of the reaction.
Syntheses, Crystal Structures, and Magnetic Properties of Two Cyano‐Bridged CrIIIMII (M = Cu, Ni) Bimetallic Assemblies with Macrocyclic Ligands
Authors: Shen Xiaoping , Zhou Hongbo , Zhang Qian , Xu Yan , Zhou Hu 
Published: September 2012

AbstractTwo new cyano‐bridged molecule‐based magnets, [(CuL4)2{Cr(CN)6}2]n·n[Cu(H2O)2L4]·4nCH3OH·2nH2O (1) (L4 = 3,10‐dibutyl‐1,3,5,8,10,12‐hexaazacyclotetradecane) and [(NiL3)3{Cr(CN)6}2]n·6nH2O (2) (L3 = 3,10‐dipropyl‐1,3,5,8,10,12‐hexaazacyclotetradecane), have been prepared by self‐assembly of [Cr(CN)6]3– and [M(macrocycle)]2+ (M = Cu, Ni) building blocks and characterized by elemental analysis, IR spectroscopy, thermoanalysis, single‐crystal X‐ray structure analysis and magnetic measurements. The structure of 1 mainly consists of cyanide‐bridged CrIII–CuII 1D anionic chains of [(CuL4)2{Cr(CN)6}2]n2n–, in which each [Cr(CN)6]3– unit connects to two [CuL4]2+ units through its two cis C≡N groups and each [CuL4]2+ unit is linked to two [Cr(CN)6]3– ions in trans positions. Complex 2 shows an infinite 2D honeycomb sheet structure, in which each [Cr(CN)6]3– unit connects to three NiII ions through three fac‐CN– groups, and the bridging cyanide ligands coordinate to the NiII ion in a trans fashion forming trans‐NiL3(N≡C)2 moieties. Magnetic studies reveal that both 1 and 2 exhibit ferromagnetic behavior with long range magnetic ordering at Tc of 15 and 10 K, respectively.
Electrophoretic Preparation of an Organic–Inorganic Hybrid of Layered Metal Hydroxide and Hydrogel for a Potential Drug‐Delivery System
Authors: Gwak Gyeong‐Hyeon , Paek Seung‐Min , Oh Jae‐Min 
Published: September 2012

AbstractWe have prepared organic–inorganic hybrid materials consisting of layered metal hydroxides and hydrogel polymers for potential use as a drug delivery system. The hybrid materials were synthesized by an electrophoretic method; anionic precursors, OH–/CO32–, and cationic metal Zn2+ were migrated into hydrogel by applying an electrical potential of 25 V for 20 min to form inorganic nanocrystals inside the hydrogel matrix. Hydrozincite [Zn5(OH)8(CO3)] nanoparticles, a kind of layered metal hydroxide, were determined to develop inside the hydrogel according to powder X‐ray diffraction, FTIR, and X‐ray absorption spectroscopy. Scanning electron microscopic images showed that the prepared hybrid materials have well‐dispersed inorganic nanoparticles in the hydrogel matrix. In order to evaluate the potential of the thus prepared hybrid materials as a drug‐delivery system, the well‐known antioxidant ferulic acid was incorporated and their time‐dependent release profile was obtained by HPLC.
Bleaching augments lipid peroxidation products in pistachio oil and its cytotoxicity
Authors: Racicot Kenneth , Craven Andrew , Chen C.‐Y. Oliver 
Published: September 2012

AbstractPistachio consumption is associated with reductions in serum cholesterol and oxidative stress due to their constituents of unsaturated fats, phytosterols, fiber, and antioxidants. Bleaching has been applied to whiten nut shells for antifungal and cosmetic purposes. However, the impact of bleaching on nutritional quality and safety of pistachios remains to be examined. In this study, we investigated whether bleaching would increase malondialdehyde (MDA) or 7‐keto‐sitosterol and decrease phytosterols in pistachio oil, as well as cause cytotoxicity of modeled Hepa1c1c7 cells. Bleaching increased MDA by more than 32% from 0.23 µg/g in raw oil, with the largest increase noted with the bleach containing H2O2 and Fe2+ (P ≤ 0.05). Bleached pistachio oil had larger than 12.6% decrease in β‐sitosterol and total phytosterols as compared to the raw oil (P ≤ 0.05). Bleaching with Fe2+ significantly increase 7‐keto‐sitosterol compared to bleaching alone. Hepatic cell viability was decreased the most by the oil of the pistachios treated with bleach containing Fe2+ (P ≤ 0.05), and lactate dehydrogenase activity in medium was elevated by >18‐folds (P ≤ 0.05). Compared to natural pistachios, the bleaching treatment had detrimental effects on nutritional quality and expected health benefits of pistachios by increasing lipid peroxidation, decreasing phytosterol content, and causing cytotoxicity.Practical applications: Bleaching has been applied to whiten the nut shell for antifungal and cosmetic purposes. However, the results of this study indicate that bleaching treatment has a detrimental impact on nutritional quality and expected health benefits of pistachios. Particularly, treatment with a bleach formula with hydrogen peroxide and transit metals increases formation of lipid peroxidation products and decreases phytosterol content. The resulting pistachio oil causes cell toxicity. Thus, bleaching practice for whitening pistachios is strongly discouraged.
Chemoselective O‐Benzylation of the Propargylic Hydroxy Group in Polyols
Authors: Lee Ji Ho , Oh Chang Ho 
Published: September 2012

AbstractWe have discovered the highly chemoselective benzylation of propargylic hydroxy groups in the presence of other hydroxy groups under very usual conditions involving benzyl bromide and sodium hydroxide in DMF at room temperature. This methodology has a high synthetic utility for the selective protection of hydroxy groups at the propargylic position among various other hydroxy groups in complex molecules.