bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey analysis of chorus intensity at Saturn
Authors: Menietti J. D. , Averkamp T. F. , Groene J. B. , Horne R. B. , Shprits Y. Y. , Woodfield E. E. , Hospodarsky G. B. , Gurnett D. A.
Published: October 2014

In order to conduct theoretical studies or modeling of pitch angle scattering of electrons by whistler mode chorus emission at Saturn, a knowledge of chorus occurrence and magnetic intensity levels, PB, as well as the distribution of PB relative to frequency and spatial parameters is essential. In this paper an extensive survey of whistler mode magnetic intensity levels at Saturn is carried out, and Gaussian fits of PB are performed. We fit the spectrum of wave magnetic intensity between the lower hybrid frequency and fceq/2 and for frequencies in the interval fceq/2 < f < 0.9 fceq, where fceq is the cyclotron frequency mapped to the equator. Saturn chorus is observed over most local times, but is dominant on the nightside in the range of 4.5 < L <7.5, with minimum power at the equator and peak power in the range of 5° < λ < 10°. Saturn wave magnetic intensity averaged in frequency bins peaks in the range of 10−5 < PB < 10−4 nT2 for 0.4 < β < 0.5 (β = f/fceq). Gaussian fits of PB with frequency and latitude are obtained for lower band chorus. Plasma injection regions are occasionally encountered with significant chorus power levels. Upper band chorus is seen almost exclusively within plasma injection regions, and the number of events is very limited, but when present, the average levels of PB can be higher than the lower band chorus. The overall magnetic intensity contribution of the upper band, however, is insignificant relative to the lower band.
The impact of static stress change, dynamic stress change, and the background stress on aftershock focal mechanisms
Authors: Hardebeck Jeanne L.
Published: October 2014

The focal mechanisms of earthquakes in Southern California before and after four M ≥ 6.7 main shocks provide insight into how fault systems respond to stress and changes in stress. The main shock static stress changes have two observed impacts on the seismicity: changing the focal mechanisms in a given location to favor those aligned with the static stress change and changing the spatial distribution of seismicity to favor locations where the static stress change aligns with the background stress. The aftershock focal mechanisms are significantly aligned with the static stress changes for absolute stress changes of ≥ 0.02 MPa, for up to ~20 years following the main shock. The dynamic stress changes have similar, although smaller, effects on the local focal mechanisms and the spatial seismicity distribution. Dynamic stress effects are best observed at long periods (30–60 s) and for metrics based on repeated stress cycling in the same direction. This implies that dynamic triggering operates, at least in part, through cyclic shear stress loading in the direction of fault slip. The background stress also strongly controls both the preshock and aftershock mechanisms. While most aftershock mechanisms are well oriented in the background stress field, 10% of aftershocks are identified as poorly oriented outliers, which may indicate limited heterogeneity in the postmain shock stress field. The fault plane orientations of the outliers are well oriented in the background stress, while their slip directions are not, implying that the background stress restricts the distribution of available fault planes.
Proxy interpretation of coral‐recorded seawater δ18O using 1‐D model forced by isotope‐incorporated GCM in tropical oceanic regions
Authors: Liu Gang , Kojima Keitaro , Yoshimura Kei , Oka Akira
Published: October 2014

The oxygen isotopic ratio in the seawater (δ18Osw) recorded in δ18O of coral skeleton for several centuries in tropical regions is an important variable for reconstructing the past climate. However, the relationship between δ18Osw and hydrological balance has not been clearly uncovered yet. In this study, a one‐dimensional ocean budget model forced by the global quasi‐reanalysis isotope data, which is the output of an isotope‐incorporated global spectral model, is employed to simulate δ18Osw. The results from the simulations are compared with 31 coral records in tropical oceanic regions. The 1‐D model successfully reproduces δ18Osw in 21 coral records, indicating these corals have the potential to reconstruct the local hydrological budget. The results also confirm that the reproducibility of the 1‐D model generally increases with the annual precipitation variability. However, in the regions where the precipitation variability is less, it is more difficult to reconstruct climatic information from the δ18Osw, since the nonlocal physical processes unaccounted for in the 1‐D model may affect δ18Osw. The sensitivity analysis of the 1‐D model shows that in tropical oceanic regions, the large‐scale precipitation is the dominant factor for δ18Osw, confirming that δ18Osw recorded in the coral records is a proxy for the precipitation anomaly. This study implies that δ18Osw is more closely associated with precipitation and local water isotope budget in tropical oceanic regions than elsewhere, and that the 1‐D model is a useful approach for the proxy interpretation in tropical oceanic regions.
On the origin of the Vastitas Borealis Formation in Chryse and Acidalia Planitiae, Mars
Authors: Salvatore M. R. , Christensen P. R.
Published: October 2014

The geologic history of the northern plains of Mars has been extensively debated. Specifically, the Vastitas Borealis Formation (VBF) represents an enigmatic surface unit that exhibits flow morphologies at its boundary, extensive surface fracturing, tens of thousands of small mounds, and unique crater morphologies. Here we test the hypothesis that the VBF in the region of Chryse and Acidalia Planitiae, Mars, originated through the compaction and later expulsion of fluid‐laden sediments sourced from the shallow subsurface. We find that the morphological, thermophysical, and spectral properties of the VBF marginal unit, in addition to the recent identification of fine‐grained sedimentary layers in the shallow subsurface, are all consistent with such a formation mechanism. Estimates of volume loss based on “collar‐like” morphologies present on high‐standing buttes suggest that a minimum fluid volume of ~13,500 km3 was expelled from the subsurface, making the VBF a significant ancient hydrologic reservoir on the Martian surface. This formation mechanism lends additional insight into the sedimentary and aqueous history of the northern plains of Mars and unites morphologic, spectral, thermophysical, and structural observations under one consistent formation hypothesis.
Monitoring motion and measuring relative position of the Chang'E‐3 rover
Authors: Liu Qinghui , Zheng Xin , Huang Yong , Li Peijia , He Qingbao , Wu Yajun , Guo Li , Tang Mingle
Published: October 2014

Same‐beam very long baseline interferometry observations were performed between the rover and the lander of Chang'E‐3 and differential phase delay data were obtained with the minimum random error of about 0.03 ps. These data were used to monitor the rover motions, as small as several centimeters, including movement, turning, and attitude adjustment. The relative position between the rover and the lander was precisely measured with an accuracy of 1 m, which is an improvement of 10 times compared with that of the Apollo project.
Wind‐driven nearshore sediment resuspension in a deep lake during winter
Authors: Reardon Kristin E. , Bombardelli Fabián A. , Moreno‐Casas Patricio A. , Rueda Francisco J. , Schladow S. Geoffrey
Published: October 2014

Ongoing public concern over declining water quality at Lake Tahoe, California‐Nevada (USA) led to an investigation of wind‐driven nearshore sediment resuspension that combined field measurements and modeling. Field data included: wind speed and direction, vertical profiles of water temperature and currents, nearbed velocity, lakebed sediment characteristics, and suspended sediment concentration and particle size distribution. Bottom shear stress was computed from ADV‐measured nearbed velocity data, adapting a turbulent kinetic energy method to lakes, and partitioned according to its contributions attributed to wind‐waves, mean currents, and random motions. When the total shear stress exceeded the critical shear stress, the contribution to overall shear stress was about 80% from wind‐waves and 10% each from mean currents and random motions. Therefore, wind‐waves were the dominant mechanism resulting in sediment resuspension as corroborated by simultaneous increases in shear stress and total measured sediment concentration. The wind‐wave model STWAVE was successfully modified to simulate wind‐wave‐induced sediment resuspension for viscous‐dominated flow typical in lakes. Previous lake applications of STWAVE have been limited to special instances of fully turbulent flow. To address the validity of expressions for sediment resuspension in lakes, sediment entrainment rates were found to be well represented by a modified 1991 García and Parker formula. Last, in situ measurements of suspended sediment concentration and particle size distribution revealed that the predominance of fine particles (by particle count) that most negatively impact clarity was unchanged by wind‐related sediment resuspension. Therefore, we cannot assume that wind‐driven sediment resuspension contributes to Lake Tahoe's declining nearshore clarity.
Multisensor earth observations to characterize wetlands and malaria epidemiology in Ethiopia
Authors: Midekisa Alemayehu , Senay Gabriel B. , Wimberly Michael C.
Published: October 2014

Malaria is a major global public health problem, particularly in Sub‐Saharan Africa. The spatial heterogeneity of malaria can be affected by factors such as hydrological processes, physiography, and land cover patterns. Tropical wetlands, for example, are important hydrological features that can serve as mosquito breeding habitats. Mapping and monitoring of wetlands using satellite remote sensing can thus help to target interventions aimed at reducing malaria transmission. The objective of this study was to map wetlands and other major land cover types in the Amhara region of Ethiopia and to analyze district‐level associations of malaria and wetlands across the region. We evaluated three random forests classification models using remotely sensed topographic and spectral data based on Shuttle Radar Topographic Mission (SRTM) and Landsat TM/ETM+ imagery, respectively. The model that integrated data from both sensors yielded more accurate land cover classification than single‐sensor models. The resulting map of wetlands and other major land cover classes had an overall accuracy of 93.5%. Topographic indices and subpixel level fractional cover indices contributed most strongly to the land cover classification. Further, we found strong spatial associations of percent area of wetlands with malaria cases at the district level across the dry, wet, and fall seasons. Overall, our study provided the most extensive map of wetlands for the Amhara region and documented spatiotemporal associations of wetlands and malaria risk at a broad regional level. These findings can assist public health personnel in developing strategies to effectively control and eliminate malaria in the region.
Pseudo‐natural Light for Displays and Lighting
Authors: Jou Jwo‐Huei , Chou Kun‐Yi , Yang Fu‐Chin , Hsieh Ching‐Heng , Kumar Sudhir , Agrawal Abhishek , Chen Sun‐Zen , Li Tsung‐Han , Yu Hui‐Huan
Published: October 2014

Light quality shows strong effects on humans in many aspects, including aesthetics, psychology, physiology, and health. By assuming that natural light has the best light quality, devising a pseudo‐natural light is hence important and critical. Here, an all‐weather pseudo‐natural light is demonstrated based on a high number of broad‐band emitters. By doping six broad‐band organic light‐emitting dyes in three separate emission layers, for example, the light source can exhibit a 92–96% similarity with the sunlight from dawn to dusk, and a color gamut of 80% in terms of NTSC. By combining six narrow‐band light‐emitting diodes (LEDs), a much wider gamut of 121% NTSC is achievable, but with a slightly poor daylight similarity, i.e., ranging between 80% and 83%. The daylight similarity, however, can easily be enhanced to at least 94% upon incorporating broad‐band phosphors, even with the use of only one or two LEDs.
Nine children over the age of one year with full trisomy 13: A case series describing medical conditions
Authors: Bruns Deborah A. , Campbell Emily
Published: October 2014

Trisomy 13 (Patau syndrome), identified by Patau and colleagues [1960; Lancet 1: 790–793] is the third most common autosomal condition. Population studies indicate less than one in 10 children reaches their first birthday. In the face of mixed findings and recommendations for treatment, additional research is needed to further determine what contributes to longevity and implications for treatment for presenting medical conditions. The purpose of the present study is to report on presenting medical conditions and the presence or absence of the specific conditions (age at survey completion). Data on nine survivors (seven female, two male) with trisomy 13 indicated mean gestational age of approximately 36 weeks, birth weight ranging from 1100 to 3290 g and mean length of 45.3 cm. Length of hospital stay after birth varied. The majority of infants presented with well‐known physical characteristics. Medical conditions and their treatment varied at birth and at survey completion. Notably, several infants' cardiac anomalies resolved without surgical intervention. Surgeries were provided for a range of conditions including gastrostomy tube placement to address feeding issues and removal of intestinal blockage. There were no reports of holoprosencephaly. Implications and recommendations are provided. © 2014 Wiley Periodicals, Inc.
SNOT‐22 quality of life domains differentially predict treatment modality selection in chronic rhinosinusitis
Authors: DeConde Adam S. , Mace Jess C. , Bodner Todd , Hwang Peter H. , Rudmik Luke , Soler Zachary M. , Smith Timothy L.
Published: October 2014

Background

Prior study demonstrated that baseline 22‐item Sino‐Nasal Outcome Test (SNOT‐22) aggregate scores accurately predict selection of surgical intervention in patients with chronic rhinosinusitis (CRS). Factor analysis of the SNOT‐22 survey has identified five distinct domains that are differentially impacted by endoscopic sinus surgery (ESS). This study sought to quantify SNOT‐22 domains in patient cohorts electing both surgical or medical management and postinterventional change in these domains.

Methods

CRS patients were prospectively enrolled into a multi‐institutional, observational cohort study. Subjects elected continued medical management or ESS. SNOT‐22 domain scores at baseline were compared between treatment cohorts. Postintervention domain score changes were evaluated in subjects with at least six‐month follow‐up.

Results

A total of 363 subjects were enrolled with 72 (19.8%) electing continued medical management, whereas 291 (80.2%) elected ESS. Baseline SNOT‐22 domain scores were comparable between treatment cohorts in sinus‐specific domains (rhinologic, extranasal rhinologic, and ear/facial symptoms; p > 0.050); however, the surgical cohort reported significantly higher psychological (mean ± standard deviation [SD]: 16.0 ± 8.4 vs 12.0 ± 7.1; p < 0.001) and sleep dysfunction (13.7 ± 6.8 vs 10.5 ± 6.2; p < 0.001) than the medical cohort. Effect sizes for ESS varied across domains with rhinologic and extranasal rhinologic symptoms experiencing the greatest gains (1.067 and 0.997, respectively), whereas psychological and sleep dysfunction experiencing the smallest improvements (0.805 and 0.818, respectively). Patients experienced greater mean improvements after ESS in all domains compared to medical management (p < 0.001).

Conclusion

Subjects electing ESS report higher sleep and psychological dysfunction compared to medical management but have comparable sinus‐specific symptoms. Subjects undergoing ESS experience greater gains compared to medical management across all domains; however, these gains are smallest in the psychological and sleep domains.
Synthesis and Ligand Modification Chemistry of a Molybdenum Dinitrogen Complex: Redox and Chemical Activity of a Bis(imino)pyridine Ligand
Authors: Margulieux Grant W. , Turner Zoë R. , Chirik Paul J.
Published: October 2014

The bis(imino)pyridine 2,6‐(2,6‐iPr2‐C6H3NCPh)2‐C5H3N (iPrBPDI) molybdenum dinitrogen complex, [{(iPrBPDI)Mo(N2)}2(μ2,η1,η1‐N2)] has been prepared and contains both weakly (terminal) and modestly (bridging) activated N2 ligands. Addition of ammonia resulted in sequential NH bond activations, thus forming bridging parent imido (μ‐NH) ligands with concomitant reduction of one of the imines of the supporting chelate. Using primary and secondary amines, model intermediates have been isolated that highlight the role of metal–ligand cooperativity in NH3 oxidation.
Diagnosis of Toxoplasmosis Using a Synthetic Glycosylphosphatidylinositol Glycan
Authors: Götze Sebastian , Azzouz Nahid , Tsai Yu‐Hsuan , Groß Uwe , Reinhardt Anika , Anish Chakkumkal , Seeberger Peter H. , Varón Silva Daniel
Published: October 2014

Around 2 billion people worldwide are infected with the apicomplexan parasite Toxoplasma gondii which induces a variety of medical conditions. For example, primary infection during pregnancy can result in fetal death or mental retardation of the child. Diagnosis of acute infections in pregnant women is challenging but crucially important as the drugs used to treat T. gondii infections are potentially harmful to the unborn child. Better, faster, more reliable, and cheaper means of diagnosis by using defined antigens for accurate serological tests are highly desirable. Synthetic pathogen‐specific glycosylphosphatidylinositol (GPI) glycan antigens are diagnostic markers and have been used to distinguish between toxoplasmosis disease states using human sera.
Supramolecular Architectures from Bent‐Core Dendritic Molecules
Authors: Cano Miguel , Sánchez‐Ferrer Antoni , Serrano José Luis , Gimeno Nélida , Ros M. Blanca
Published: October 2014

Control of the self‐assembly of small molecules to generate architectures with diverse shapes and dimensions is a challenging research field. We report unprecedented results on the ability of ionic, bent dendritic molecules to aggregate in water. A range of analytical techniques (TEM, SEM, SAED, and XRD) provide evidence of the formation of rods, spheres, fibers, helical ribbons, or tubules from achiral molecules. The compact packing of the bent‐core structures, which promotes the bent‐core mesophases, also occurs in the presence of a poor solvent to provide products ranging from single objects to supramolecular gels. The subtle balance of molecule/solvent interactions and appropriate molecular designs also allows the transfer of molecular conformational chirality to morphological chirality in the overall superstructure. Functional motifs and controlled morphologies can be combined, thereby opening up new prospects for the generation of nanostructured materials through a bottom‐up strategy.
Isolation of a Three‐Coordinate Boron Cation with a Boron–Sulfur Double Bond
Authors: Franz Daniel , Irran Elisabeth , Inoue Shigeyoshi
Published: October 2014

The reaction of the bulky bis(imidazolin‐2‐iminato) ligand precursor (1,2‐(LMesNH)2‐C2H4)[OTs]2 (12+ 2[OTs]−; LMes=1,3‐dimesityl imidazolin‐2‐ylidene, OTs=p‐toluenesulfonate) with lithium borohydride yields the boronium dihydride cation (1,2‐(LMesN)2‐C2H4)BH2[OTs] (2+ [OTs]−). The boronium cation 2+ [OTs]− reacts with elemental sulfur to give the thioxoborane salt (1,2‐(LMesN)2‐C2H4)BS[OTs] (3+ [OTs]−). The hitherto unknown compounds 12+ 2[OTs]−, 2+ [OTs]−, and 3+ [OTs]− were fully characterized by spectroscopic methods and single‐crystal X‐ray diffraction. Moreover, DFT calculations were carried out to elucidate the bonding situation in 2+ and 3+. The theoretical, as well as crystallographic studies reveal that 3+ is the first example for a stable cationic complex of three‐coordinate boron that bears a BS double bond.
Dendritic Ionic Liquids Based on Imidazolium‐Modified Poly(aryl ether) Dendrimers
Authors: Qin Tianyi , Li Xuying , Chen Jinping , Zeng Yi , Yu Tianjun , Yang Guoqiang , Li Yi
Published: October 2014

A series of dendritic ionic liquids (DILs) based on imidazolium‐modified poly(aryl ether) dendrimers IL‐Br‐Gn (n=0–3) were synthesized by a modified convergent approach and “click” chemistry. The resulting DILs exhibited high thermal resistance with decomposition temperatures up to 270 °C and low glass transition temperatures in the range of approximately −5–0 °C. All IL‐Br‐Gn were found to be miscible with water at any ratio and could encapsulate hydrophobic molecules. The reversible phase transfer of the DILs between the aqueous and organic phases was accomplished by simple anion exchange between the hydrophilic Br− anion and the hydrophobic bis(trifluoromethylsulfonyl)amide anion (NTf2−). IL‐Br‐Gn could be used as transporters to shuttle hydrophobic molecules between the organic and aqueous phases efficiently. The present work provides a new kind of transporting materials with potential applications in substance separation, drug delivery, and biomolecule transport.
Tetrathio and Tetraseleno[8]circulenes: Synthesis, Structures, and Properties
Authors: Xiong Xiaodong , Deng Chun‐Lin , Minaev Boris F. , Baryshnikov Gleb V. , Peng Xiao‐Shui , Wong Henry N. C.
Published: October 2014

Novel sulfur and selenium‐bridged [8]circulenes were prepared from octabromotetraphenylene. Structures of these compounds were unambiguously confirmed by X‐ray crystallographic analyses. Photophysical and electrochemical investigations of these [8]circulenes suggest their potential applications as electronic materials. The antiaromatic nature of tetrathio[8]circulene and tetraselenium[8]circulene was studied by computational methods, and the NICS computational results reveal that the central eight‐membered ring has highly antiaromatic character.
Enhancing functional expression of heterologous proteins through random substitution of genetic codes in the 5' coding region
Authors: Cheong Dae‐Eun , Ko Kyong‐Cheol , Han Yunjon , Jeon Ho‐Geun , Sung Bong Hyun , Kim Geun‐Joong , Choi Jong Hyun , Song Jae Jun
Published: October 2014

Recent studies using heterologous protein expression systems suggest that synonymous codons affect not only the expression but also the properties of the expressed protein. However, practical application of this information is challenging, and to date, efforts to employ bioinformatics tools to design synonymous codon mixes have been only marginally successful. Here, we sought to enhance the functional expression of heterologous protein in Escherichia coli through completely random substitution of the first ten codons with synonymous codons, using a previously isolated exocellulase CelEdx‐SF301 as the model protein. Synonymous codon variants were generated by PCR using forward primers with mixed nucleotides at the third position in each codon and a conventional reverse primer. The resulting PCR products were inserted upstream of the fluorescent protein mCherry without linkers. After transformation and cultivation, colonies exhibiting red fluorescence were selected, and the activity of SF301‐mCherry fusion proteins was tested. Synonymous codon variant fusion proteins exhibited 35‐ to 530‐fold increases in functional expression compared with wild‐type controls. Unlike results from other reports, we found that the stability of mRNA secondary structure in the 5' untranslated region and codon rarity were not correlated with functional expression level. Our work demonstrates that a completely random mixed of synonymous codons effectively enhances functional expression levels without the need for amino acid substitutions. Biotechnol. Bioeng. 2015;112: 822–826. © 2014 Wiley Periodicals, Inc.
Mineralization initiation of MC3T3‐E1 preosteoblast is suppressed under simulated microgravity condition
Authors: Hu Li‐fang , Li Jing‐bao , Qian Ai‐rong , Wang Fei , Shang Peng
Published: October 2014

Microgravity decreases the differentiation of osteoblast. However, as this process is multistage and complex, the mechanism by which microgravity inhibits osteoblast differentiation is still unclear. We have previously found that 24 h acute treatment of simulated microgravity (SM) with a random positioning machine (RPM) significantly inhibited the differentiation of preosteoblasts and have explored whether osteoblasts show different response to microgravity condition at other stages, such as the mineralizing‐stage. Murine MC3T3‐E1 preosteoblasts induced for osteogenic differentiation for seven days were cultured either under normal gravity or SM conditions for 24 h. SM treatment significantly suppressed mineralized nodule formation. Alkaline phosphatase (ALP) activity was dramatically decreased, and the expression of ALP gene was downregulated. Expression of well‐known markers and regulators for osteoblasts differentiation, including osteocalcin (OC), type I collagen α1 (Col Iα1), dentin matrix protein 1 (DMP1) and runt‐related transcription factor 2 (Runx2), were downregulated. Western blot analysis showed that the phosphorylated extracellular signal‐regulated kinase (p‐ERK) level was lower under SM condition. Thus, the initiation of osteoblast mineralization is suppressed by SM condition, and the suppression may be through the regulation of ALP activity and the osteogenic gene expression. ERK signaling might be involved in this process. These results are relevant to the decrease of osteoblast maturation and bone formation under microgravity condition.
Highly Efficient and Magnetically Recoverable Niobium Nanocatalyst for the Multicomponent Biginelli Reaction
Authors: Lima Carolina G. S. , Silva Sandrina , Gonçalves Ricardo H. , Leite Edson R. , Schwab Ricardo S. , Corrêa Arlene G. , Paixão Márcio W.
Published: October 2014

A new magnetically recoverable nanocatalyst was prepared by coating magnetite with niobium oxide (Fe3O4@Nb2O5) by using a simple wet impregnation method. The Fe3O4@Nb2O5 nanocatalyst was fully characterized, and its catalytic activity was evaluated by using the one‐pot, three‐component Biginelli reaction, with the aim to synthesize 1,4‐dihydropyrimidinones, a class of compounds with diverse pharmacological properties. The developed protocol was applied to a wide range of aliphatic and aromatic substrates, and structurally diverse products were obtained in excellent yields. Compared with copper and nickel nanocatalysts, the Fe3O4@Nb2O5 nanocatalyst demonstrated superior catalytic activity at a remarkably low catalyst loading (0.1 mol %). This niobium nanocatalyst could be easily separated from the reaction mixture with an external magnet and was reused several times without any loss of its catalytic activity. Moreover, although the Biginelli reaction is a century‐old reaction, its mechanism is still a controversial subject, and our investigation provided an insight into the reaction mechanism.
Control of Chiral Nanostructures by Self‐Assembly of Designed Amphiphilic Peptides and Silica Biomineralization
Authors: Huang Zhehao , Yao Yuan , Han Lu , Che Shunai
Published: October 2014

Peptides, the fundamental building units of biological systems, are chiral in molecular scale as well as in spatial conformation. Shells are exquisite examples of well‐defined chiral structures produced by natural biomineralization. However, the fundamental mechanism of chirality expressed in biological organisms remains unclear. Here, we present a system that mimics natural biomineralization and produces enantiopure chiral inorganic materials with controllable helicity. By tuning the hydrophilicity of the amphiphilic peptides, the chiral morphologies and mesostructures can be changed. With decreasing hydrophilicity of the amphiphilic peptides, we observed that the nanostructures changed from twisted nanofibers with a hexagonal mesostructure to twisted nanoribbons with a lamellar mesostructure, and the extent of the helicity decreased. Defining the mechanism of chiral inorganic materials formed from peptides by noncovalent interactions can improve strategies toward the bottom‐up synthesis of nanomaterials as well as in the field of bioengineering.
Phosphorescent Polymeric Nanoparticles by Coordination Cross‐Linking as a Platform for Luminescence Imaging and Photodynamic Therapy
Authors: Lu Yang , Xue Fengfeng , Zhou Zhiguo , Shi Min , Yan Yuping , Qin Lijie , Yang Hong , Yang Shiping
Published: October 2014

Water‐soluble phosphorescent polymeric nanoparticles with an average diameter of approximately 100 nm were synthesized by a coordination cross‐linking reaction. The pyridine blocks in poly(4‐vinyl pyridine‐b‐ethylene oxide) (P4VP‐b‐PEO) were cross‐linked by the iridium chloride‐bridged dimer in DMF solution. Owing to the presence of an iridium complex with different ligands in the core of the polymeric nanoparticles, NP‐1, NP‐2, and NP‐3 showed bright green, yellow, and red phosphorescence, respectively. PEG chains in the shell gave the polymeric nanoparticles solubility and biocompatibility, which was confirmed by an MTT assay using HeLa cells as a model cancer cell line. The flow cytometry and laser confocal fluorescence microscopy results revealed NP‐2, as an example, could be effectively uptaken by HeLa cells. Therefore, these polymeric nanoparticles can be used as luminescent probes for living cells. In addition, 1O2 could be effectively generated in the presence of NP‐2 upon irradiation with visible light (λ>400 nm, 300 mW cm−2), which was confirmed by a clear decrease in the fluorescence intensity of 9,10‐dimethylanthracene (DMA). After incubation with NP‐2 at a concentration of 200 μg mL−1 for 6 h, approximately 90 % of HeLa cells were effectively ablated upon irradiation with visible light for only 10 min, indicating the potential for photodynamic therapy with polymeric nanoparticles.
Phosphine‐Free Stille–Migita Chemistry for the Mild and Orthogonal Modification of DNA and RNA
Authors: Krause André , Hertl Alexander , Muttach Fabian , Jäschke Andres
Published: October 2014

An optimized catalyst system of [Pd2(dba)3] and AsPh3 efficiently catalyzes the Stille reaction between a diverse set of functionalized stannanes and halogenated mono‐, di‐ and oligonucleotides. The methodology allows for the facile conjugation of short and long nucleic acid molecules with moieties that are not compatible with conventional chemical or enzymatic synthesis, among them acid‐, base‐, or fluoride‐labile protecting groups, fluorogenic and synthetically challenging moieties with good to near‐quantitative yields. Notably, even azides can be directly introduced into oligonucleotides and (deoxy)nucleoside triphosphates, thereby giving direct access to “clickable” nucleic acids.
Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non‐Heme Iron(III) Complexes
Authors: Jastrzebski Robin , Quesne Matthew G. , Weckhuysen Bert M. , de Visser Sam P. , Bruijnincx Pieter C. A.
Published: October 2014

Catechol intradiol dioxygenation is a unique reaction catalyzed by iron‐dependent enzymes and non‐heme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational modelling of multiple iron(III) catecholato complexes, we have elucidated the catechol cleavage mechanism and show that oxygen binds the iron center by partial dissociation of the substrate from the iron complex. The iron(III) superoxide complex that is formed subsequently attacks the carbon atom of the substrate by a rate‐determining CO bond formation step.
ChemInform Abstract: Oligomeric Rare‐Earth Metal Cluster Complexes with Endohedral Transition Metal Atoms.
Authors: Steinberg Simon , Zimmermann Sina , Bruehmann Matthias , Meyer Eva , Rustige Christian , Wolberg Marike , Daub Kathrin , Bell Thomas , Meyer Gerd
Published: October 2014

Comproportionation reactions of LnX3 (Ln: Sc, Y, La, Gd, Tb, Dy, Ho and X: Cl, Br, I) with the respective rare‐earth metals Ln and transition metals M (M: Ru, Rh, Os, Ir, Fe, Co) at 800—1050 °C leads to the formation of 19 new compounds.
ChemInform Abstract: Imidazole: Having Versatile Biological Activities
Authors: Verma Amita , Joshi Sunil , Singh Deepika
Published: October 2014

Review: 26 refs.
ChemInform Abstract: Catalytic Aspects of Ceria Zirconia Solid Solution: Part‐II an Overview on Recent Developments in the Heterogeneous Catalytic Applications of Metal Loaded Ceria‐zirconia Solid Solution
Authors: Pudukudy Manoj , Yaakob Zahira
Published: October 2014

Review: 234 refs.
Selector Screening for Enantioseparation of dl‐α‐Methyl Phenylglycine Amide by Liquid–Liquid Extraction
Authors: Schuur Boelo , Blahušiak Marek , Vitasari Caecilia R. , Gramblička Michal , De Haan André B. , Visser Ton J.
Published: October 2014

Enantioseparation through liquid extraction technology is an emerging field, e.g., enantioseparations of amino acids (and derivatives thereof), amino alcohols, amines, and carboxylic acids have been reported. Often, when a new selector is developed, the versatility of substrate scope is investigated. From an industrial point of view, the problem is typically approached the other way around, and for a target racemate, a selector needs to be found in order to accomplish the desired enantioseparation. This study presents such a screening approach for the separation of the enantiomers of dl‐α‐methyl phenylglycine amide (dl‐α‐MPGA), a model amide racemate with high industrial relevance. Chiral selectors that were reported for other classes of racemates were investigated, i.e., several macrocyclic selectors and Pd‐BINAP complexes. It appeared very challenging to obtain both high extraction yields and good enantioselectivity for most selectors, but Pd‐BINAP‐based selectors performed well, with enantioselectivities up to 7.4 with an extraction yield of the desired enantiomer of 95.8%. These high enantioselectivities were obtained using dichloromethane as solvent. Using less volatile chlorobenzene or 1‐chloropentane, reasonable selectivities of up to 1.7 were measured, making these the best alternative solvents for dichloromethane. Chirality 27:123–130, 2015. © 2014 Wiley Periodicals, Inc.
Is High‐Intensity Statin Therapy Associated With Lower Statin Adherence Compared With Low‐ to Moderate‐Intensity Statin Therapy? Implications of the 2013 American College of Cardiology/American Heart Association Cholesterol Management Guidelines
Authors: Virani Salim S. , Woodard LeChauncy D. , Akeroyd Julia M. , Ramsey David J. , Ballantyne Christie M. , Petersen Laura A.
Published: October 2014

Background

The recent cholesterol guideline recommends high‐intensity statins in cardiovascular disease (CVD) patients. High‐intensity statins are associated with more frequent side effects. Therefore, it may be of concern that these recommendations might reduce statin adherence.

Hypothesis

High‐intensity statins are associated with lower adherence compared with low‐ to moderate‐intensity statins.

Methods

In a national database of 972 532 CVD patients from the Veterans Health Administration, we identified patients receiving statins between October 1, 2010, and September 30, 2011. We assessed statin adherence by calculating proportion of days covered (PDC) and determined whether high‐intensity statin therapy was independently associated with a lower PDC.

Results

Statins were prescribed in 629 005 (64.7%). Of those, 229 437 (36.5%) received high‐intensity statins. Mean PDC (0.87 vs 0.86, P < 0.0001) and patients with PDC ≥0.80 (76.3% vs 74.2%, P < 0.0001) were slightly higher for those receiving low‐ to moderate‐intensity compared with high‐intensity statins. In adjusted analyses, high‐intensity statin use was associated with a significant but modest PDC reduction compared with low‐ to moderate‐intensity statin use, whether PDC was assessed as a continuous (β‐coefficient: −0.008, P < 0.0001) or categorical (PDC ≥0.80 [odds ratio: 0.94, 95% confidence interval: 0.93‐0.96]) measure of statin adherence.

Conclusions

An approach of high‐intensity statin therapy will lead to a significant practice change, as the majority of CVD patients are not on high‐intensity therapy. However, this change may be associated with a very modest reduction in statin adherence compared with low‐ to moderate‐intensity therapy that is unlikely to be of clinical significance.
Variations in Growth, Clonal and Sexual Reproduction of Spartina alterniflora Responding to Changes in Clonal Integration and Sand Burial
Authors: Xiao Yan , Zhao Hui , Yang Wen , Qing Hua , Zhou Changfang , Tang Junbing , An Shuqing
Published: October 2014

Clonal plants can shift their allocation to growth, clonal, and sexual reproduction under different conditions. To test this hypothesis, a greenhouse experiment was conducted to explore the effects of sand burial degrees and clonal integration on the trade‐offs among growth, clonal, and sexual reproduction in an invasive species, Spartina alterniflora. Ramets of connected genets to artificially disconnected ramets buried by sand to a depth of 0, 8, and 16 cm, respectively, were compared. Clonal integration stimulated the growth and clonal reproduction of daughter ramets, but has negative effects on these performances of mother ramets. Consequently, clonal integration had no effect on the clones. Biomass allocation to sexual reproduction in mother ramets and whole clones were stimulated by severing rhizomes. It could be concluded that the increased performances of daughter ramets occurred when mother ramets showed decreases of growth, clonal, and sexual reproduction when buried. Increased sexual reproduction in response to sand burial might represent a compensatory mechanism to reduced growth and clonal reproduction in S. alterniflora. Rhizome fragmentation did not influence growth and clonal reproduction, but increased sexual reproduction at the clone level.
Polycyclic Aromatic Hydrocarbons in the Food Web of Coastal Wetlands: Distribution, Sources and Potential Toxicity
Authors: Zhang Yu , Cui Baoshan , Zhang Qijun , Liu Xinhui
Published: October 2014

To elucidate the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in coastal wetlands and determine the potential toxicity of PAHs to the food web, we analyzed the concentrations of 16 PAHs in the water, sediments, primary producer, invertebrates, fishes, and birds of the coastal wetlands of the Yellow River Delta. The trophic level of the food web was described using the stable carbon isotopes (δ15C) and nitrogen isotopes (δ15N) in organisms. The sources of the PAHs were evaluated with characteristic ratio methods, and their potential toxicity was analyzed in accordance with toxicity equivalency factors. Results showed that the sediments contain higher amounts of PAHs than does the water. The amount of PAHs in the food web follows the order birds > fishes > invertebrates > primary producer. The amount of PAHs in the organs of birds follows the order kidney > lung > heart > liver > muscle. The PAHs concentration in migratory birds, namely, Ardea purpurea, Larus saundersi, Egretta garzetta, and Cygnus cygnus is higher than that in the resident bird Anas poecilorhyncha. The Yellow River Delta is contaminated to a lesser extent than the other wetlands. The PAHs in the coastal wetlands of the Yellow River Delta originate primarily from a mixture of petroleum and combustion sources. The potential toxicity of these PAHs is of moderate or low level. Thus, reducing the release of PAHs through petroleum and combustion sources is necessary to strengthen the protection of plants and animals in the food web of coastal wetlands.
Stimuli‐Responsive Polymeric Nanoparticles for Nanomedicine
Authors: Crucho Carina I. C.
Published: October 2014

Nature continues to be the ultimate in nanotechnology, where polymeric nanometer‐scale architectures play a central role in biological systems. Inspired by the way nature forms functional supramolecular assemblies, researchers are trying to make nanostructures and to incorporate these into macrostructures as nature does. Recent advances and progress in nanoscience have demonstrated the great potential that nanomaterials have for applications in healthcare. In the realm of drug delivery, nanomaterials have been used in vivo to protect the drug entity in the systemic circulation, ensuring reproducible absorption of bioactive molecules that do not naturally penetrate biological barriers, restricting drug access to specific target sites. Several building blocks have been used in the formulation of nanoparticles. Thus, stability, drug release, and targeting can be tailored by surface modification. Herein the state of the art of stimuli‐responsive polymeric nanoparticles are reviewed. Such systems are able to control drug release by reacting to naturally occurring or external applied stimuli. Special attention is paid to the design and nanoparticle formulation of these so‐called smart drug‐delivery systems. Future strategies for further developments of a promising controlled drug delivery responsive system are also outlined.
NaGdF4 Nanoparticles Coated with Functionalised Ethylenediaminetetraacetic Acid as Versatile Probes for Dual Optical and Magnetic Resonance Imaging
Authors: Carniato Fabio , Tei Lorenzo , Phadngam Suratchanee , Isidoro Ciro , Botta Mauro
Published: October 2014

NaGdF4 nanoparticles (NPs) coated with organic ligands are known to provide efficient “positive” contrast in magnetic resonance imaging (MRI). Strongly chelating ligands, such as ethylenediaminetetraacetic acid (EDTA) and d,l‐1,2‐diaminopropionic‐N,N,N′,N′‐tetraacetic acid (EDTACOOH), which is an EDTA derivative with a functionalisable carboxylic group, were used to coat NaGdF4. The carboxylic group was used to insert a polyethylene glycol (PEG) functionality (to give EDTAPEG) to favour better suspension and stealth and/or a fluorescent dye to obtain dual optical/MRI probes. The relaxometric behaviour of these NPs was investigated as a function of the magnetic field strength, and a significant contribution from water molecules hydrogen bonded to the organic coating was evidenced. The chemical stability of the NPs was evaluated both in a physiological medium and in the presence of a strong chelating agent. Finally, the dye‐functionalised NPs were tested in ovarian carcinoma cells as dual optical and MRI probes.
Synthesis of NiGa2O4 Octahedron Nanocrystal with Exposed {111} Facets and Enhanced Efficiency of Photocatalytic Water Splitting
Authors: Zhou Shi‐Xiong , Lv Xiao‐Jun , Zhang Chen , Huang Xing , Kang Lei , Lin Zhe‐shuai , Chen Yong , Fu Wen‐Fu
Published: October 2014

For the first time, octahedral NiGa2O4 nanocrystals having reactive pH‐dependent {111} facets are synthesized through a facile hydrothermal route without using any template or organic surfactant. The {111} facets of octahedral NiGa2O4 display clearly enhanced photocatalytic generation of hydrogen and oxygen from water splitting and good photocatalytic stability. Density functional calculations suggest that mixed statistically occupied Ga/Ni (fourfold‐ and sixfold‐coordinated Ga/Ni) are most likely to be exposed at the (111) surface of NiGa2O4, which is very favorable for enhancing the photocatalytic activities, and the photoelectrochemical properties show that the NiGa2O4 octahedron displays a better photocurrent than NiGa2O4 nanorods with the [100] growth direction. The transient photocurrent decay scan results demonstrate that the NiGa2O4 octahedron exposed {111} facet electrode exhibits a transient decay time of 4 s, whereas this time is only 2 s for NiGa2O4 nanorod electrodes with the [100] growth direction. This longer transient decay time indicates that the charge‐carrier recombination rate is lower in the NiGa2O4 octahedron electrode, which will contribute to the enhancement of the photocatalytic activity. The present study also demonstrates that designing nanostructures with the appropriate morphology and surface structures is a feasible approach for enhancing the photoexcited charge‐transfer lifetime and developing highly active semiconductor photocatalysts.
Client Attachment Status and Changes in Therapeutic Alliance Early in Treatment
Authors: Siefert Caleb J. , Hilsenroth Mark J.
Published: October 2014

Several studies have examined associations between client attachment status and therapeutic alliance. Most, however, measure alliance at a single time point only. This study is among the first to examine how client attachment relates to changes in the therapeutic alliance early in treatment. Forty‐six outpatients from a university‐based community clinic participated. Attachment status was assessed with the Relationship Questionnaire (Bartholomew & Horowitz, 1991) prior to beginning treatment. Participants rated therapeutic alliance after an evaluation feedback session and again early in psychotherapy. Fearful insecurity was associated with declines in therapeutic alliance, while attachment security was associated with increasing client–therapist bonds. Although unrelated to global alliance, preoccupied insecurity was associated with greater confident collaboration at both time points and declines in idealized relationship from the evaluation to the early therapy time point. Results are discussed in light of prior theoretical formulations and previous research. Limitations of the study are reviewed, implications for clinical practice are noted, and suggestions for future research are made. Copyright © 2014 John Wiley & Sons, Ltd.

Key Practitioner Message

Assessing client attachment status can provide clinicians with information that helps them identify clients at risk for difficulties establishing a therapeutic alliance.

Clients high in attachment security are more likely to develop strong bonds with therapists during the early portion of treatment.

Clients high in fearful insecurity are at risk for developing weaker alliances early in treatment. Such clients appear more likely to experience declines in client–therapist bond, goal‐task agreement and overall alliance early in the treatment process.

Clients high in preoccupied insecurity may enter therapy with great confidence in the therapist and willing to engage in therapy but report more conflicts with therapists in the early phase of treatment.
Formation of a CdO Layer on CdS/ZnO Nanorod Arrays to Enhance their Photoelectrochemical Performance
Authors: Van Thanh Khue , Pham Long Quoc , Kim Do Yoon , Zheng Jin You , Kim Dokyoung , Pawar Amol U. , Kang Young Soo
Published: October 2014

The performance and photocatalytic activity of the well‐known CdS/ZnO nanorod array system were improved significantly by the layer‐by‐layer heterojunction structure fabrication of a transparent conductive oxide (TCO) CdO layer on the CdS/ZnO nanorods. Accordingly, a CdO layer with a thickness of approximately 5–10 nm can be formed that surrounds the CdS/ZnO nanorod arrays after annealing at 500 °C under air. At an external potential of 0.0 V vs. Ag/AgCl, the CdO/CdS/ZnO nanorod array electrodes exhibit an increased incident photon to conversion efficiency, which is significantly higher than that of the CdS/ZnO nanorod array electrodes. The high charge separation between the electrons and holes at the interfaces of the heterojunction structure results from the specific band energy structure of the photoanode materials, and the unique high conductivity of the CdO layer is attributed to the suppression of electron–hole recombination; this suppression enhances the photocurrent density of the CdO/CdS/ZnO nanorod arrays. The photoresponse of the electrodes in an electrolytic solution without sacrificial agents indicated that the CdO layer also has the ability to suppress the well‐known photocorrosive behavior of CdS/ZnO nanorods.