bluuebunny/crossref_metadata_2025 huggingface dataset:
Fe3O4 Modified Up‐Conversion Luminescent Nanocrystals for Biological Applications
Authors: Hou Yu , Yin Zifei , Xin Hailiang , Su Yonghua , Yang Huagui
Published: October 2012

Magnetic‐luminescent nanocomposites have obtained a great deal of attention due to their potential applications in magnetic separation of cells, magnetic resonance imaging and luminescence imaging, and so on. Herein, a new and facile two‐step synthetic strategy was developed to prepare magnetic Fe3O4 modified single crystalline up‐conversion luminescent NaYF4: Yb3+, Er3+ nanocrystals using Fe3O4 nanoparticles as the seeds. Acting as the "nuclei" in the reaction, the presence of Fe3O4 nanoparticles facilitates the formation of up‐conversion NaYF4: Yb3+, Er3+ nanocrystals on their surfaces through heterogeneous nucleation process. The structure and properties of these multifunctional nanocrystals were characterized by transmission electron microscope (TEM), X‐ray photoelectron spectroscopy (XPS), photo luminescence (PL) and X‐ray diffraction (XRD). The results revealed that the as‐prepared multifunctional nanocrystals show dual distinct properties of up‐conversion fluorescent and superparamagnetism, which were cubic in shape and very uniform in size with an average size ranging 30–40 nm. These unique functionalities could be very attractive for biological systems, and some biological applications such as cell‐labelling were also demonstrated.
A Comparison Between Coronary Artery Bypass Grafting Surgery and Percutaneous Coronary Intervention for the Treatment of Unprotected Left Main Coronary Artery Disease
Authors: Qin Qing , Qian Juying , Wu Xuefeng , Fan Bing , Ge Lei , Ge Junbo
Published: October 2012

Background:

Unprotected left main coronary artery (ULMCA) disease occurs in 3% to 5% of patients with coronary artery disease and is mainly treated by coronary artery bypass grafting (CABG) surgery. Drug‐eluting stents (DESs) have renewed interest for the percutaneous coronary intervention (PCI) treatment of ULMCA stenosis. This study compared the long‐term clinical outcome of PCI with DESs or CABG in real world patients with ULMCA disease.

Hypothesis:

PCI with DESs may be a better treatment for ULMCA disease compared with CABG.

Methods:

Consecutive patients who had coronary revascularization because of ULMCA disease in Zhongshan Hospital, from May 2003 to November 2009, were retrospectively enrolled. They were classified in the PCI or the CABG group according to treatments that were given initially. Of 515 patients having follow‐up data, 233 were treated by PCI, whereas 282 were treated by CABG. The patients in the CABG group were of older age, had higher European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Synergy Between PCI With Taxus Drug‐Eluting Stent and Cardiac Surgery (SYNTAX) scores, and had longer hospitalization stays than the PCI group.

Results:

At the end of follow‐up, there was no difference in major adverse cardiac and cerebrovascular events between the 2 groups. However, the incidence of cardiac death (0.4% vs 4.6%) in the PCI group was less than that in the CABG group, whereas target vessel revascularization (7.3% vs 3.2%) was higher in the PCI group.

Conclusions:

In ULMCA disease, CABG tends to be chosen in patients with higher risk according to the EuroSCORE and SYNTAX scores. PCI with DESs seemed to have favorable early and long‐term clinical outcomes compared with CABG in our center. Clin. Cardiol. 2012 DOI: 10.1002/clc.22070

Qing Qin, MD, and Juying Qian, MD, contributed equally to this work.

The authors have no funding, financial relationships, or conflicts of interest to disclose.
Density Functional Calculations of the Anisotropic Effects of Borazine and 1,3,2,4‐Diazadiboretidine
Authors: Baranac‐Stojanović Marija , Koch Andreas , Kleinpeter Erich
Published: October 2012

On the basis of the nucleus‐independent chemical shift (NICS) concept, the anisotropic effects of two inorganic rings, namely, borazine and planar 1,3,2,4‐diazadiboretidine, are quantitatively calculated and visualized as isochemical shielding surfaces (ICSSs). Dissection of magnetic shielding values along the three Cartesian axes into contributions from σ and π bonds by the natural chemical shielding–natural bond orbital (NCS–NBO) method revealed that their appearance is not a simple reflection of the extent of (anti)aromaticity.
Interfacial and Film‐Formation Behaviour of Photoactive RuII–Bipyridyl‐Based Metallosurfactants and a Rare Example of a Monolayer‐Based Logic‐Gate Approach
Authors: Mahato Prasenjit , Saha Sukdeb , Choudhury Sipra , Das Amitava
Published: October 2012

Three derivatives of tris(bipyridyl)–ruthenium(II) complexes with different alkyl‐chain lengths (nC18H37 (1), nC14H29 (2) and nC10H21 (3)) were synthesised. All these complexes behaved as an amphiphile and their surface properties were studied at the air–water interface by measuring surface pressure–area (Π–A) isotherms. The surface morphology of the resulting films at the air–water interface was also studied by using Brewster angle microscopy. Mean molecular areas of these complexes were measured from the Π–A isotherms, which were approximately 200 Å2, thereby indicating a parallel arrangement of the Ru–bipyridyl moiety of the complexes. Mono‐ and multilayer Langmuir–Blodgett (LB) films were formed on different solid surfaces with transfer ratios close to one. Similarities in the absorption and fluorescence spectra of these amphiphiles in solution as well as in LB films deposited on a quartz surface confirmed the successful transfer of these films onto the substrates. The latter provided information about the arrangements of metallosurfactant molecules within the LB films. The two‐dimensional concentrations of these films were calculated from the Lambert–Beer law as well as from the Π–A isotherm, which confirmed regular and reproducible transfer of the complex monolayers from the air–water interface onto the quartz surface. The surface morphology of these films on various substrates was characterised by atomic force microscopy. Furthermore, by oxidising the monolayer of complex 3, a one‐input sequential logic gate was constructed.
Resource allocation for heterogeneous services in multiuser cognitive radio networks
Authors: Xu Ding , Feng Zhiyong , Zhang Ping
Published: October 2012

This paper considers a downlink cognitive radio network consisting of one cognitive base station and multiple secondary users (SUs) that shares spectrum with a primary network. Unlike most of previous studies that focus on the SUs that carry only one type of service, in this paper, the SUs that carry heterogeneous services are considered. Specifically, the SUs are classified by service types, that is, the SUs that carry nonreal‐time services and the SUs that carry real‐time services. The QoS of the nonreal‐time SUs is guaranteed by the minimum mean rate constraint, whereas the QoS of the real‐time SUs is guaranteed by the minimum instantaneous rate constraint. Under this setup, a joint subchannel, rate, and power allocation scheme based on dual optimization method is proposed to minimize the mean transmit power consumption of the cognitive base station. The complexity of the proposed scheme is linear in the number of subchannels and the number of SUs. Extensive simulation results are provided to validate the proposed resource allocation scheme. Copyright © 2012 John Wiley & Sons, Ltd.
Species delimitation and digit number in a North African skink
Authors: Brown R. P. , Tejangkura T. , El Mouden E. H. , Ait Baamrane M. A. , Znari M.
Published: October 2012

Delimitation of species is an important and controversial area within evolutionary biology. Many species boundaries have been defined using morphological data. New genetic approaches now offer more objective evaluation and assessment of the reliability of morphological variation as an indicator that speciation has occurred. We examined geographic variation in morphology of the continuously distributed skink Chalcides mionecton from Morocco and used Bayesian analyses of nuclear and mitochondrial DNA (mtDNA) loci to examine: (i) their concordance with morphological patterns, (ii) support for species delimitation, (iii) timing of speciation, and (iv) levels of gene flow between species. Four digit individuals were found at sites between Cap Rhir (in the south) and the northern extreme of the range, whereas five‐digit individuals were found in two disjunct areas: (i) south of Cap Rhir and (ii) the north of the range where they were often syntopic with four‐digit individuals. The pattern of variation in generalized body dimensions was largely concordant with that in digit number, suggesting two general morphotypes. Bayesian analyses of population structure showed that individuals from sites south of Cap Rhir formed one genetic cluster, but that northern four‐ and five‐digit individuals clustered together. Statistical support for delimitation of these genetic clusters into two species was provided by a recent Bayesian method. Phylogenetic–coalescent dating with external time calibrations indicates that speciation was relatively recent, with a 95% posterior interval of 0.46–2.66 mya. This postdates equivalent phylogenetic dating estimates of sequence divergence by approximately 1 Ma. Statistical analyses of a small number of independent loci provide important insights into the history of the speciation process in C. mionecton and support delimitation of populations into two species with distributions that are spatially discordant with patterns of morphological variation.
4,4′,5,5′‐Tetrakis(guanidinyl)binaphthyl – Synthesis and Properties of Two Redox‐Active Ligands and Oxidative C–C Coupling to Perylene Derivatives
Authors: Wiesner Sven , Ziesak Alexandra , Reinmuth Matthias , Walter Petra , Kaifer Elisabeth , Wadepohl Hubert , Himmel Hans‐Jörg
Published: October 2012

We report the synthesis and properties of the new redox‐active ligands 4,4′,5,5′‐tetrakis(tetramethylguanidinyl)binaphthyl and 4,4′,5,5′‐tetrakis(N,N′‐dimethylethyleneguanidinyl)binaphthyl. The first dinuclear zinc complexes were prepared. Oxidative C–C coupling of these compounds leads to perylene derivatives.
Enantioselective Synthesis of Succinimides by Michael Addition of 1,3‐Dicarbonyl Compounds to Maleimides Catalyzed by a Chiral Bis(2‐aminobenzimidazole) Organocatalyst
Authors: Gómez‐Torres Eduardo , Alonso Diego A. , Gómez‐Bengoa Enrique , Nájera Carmen
Published: October 2012

A wide variety of chiral succinimides have been prepared in high yields and enantioselectivities by asymmetric conjugate addition of 1,3‐dicarbonyl compounds to maleimides under very mild reaction conditions using a bifunctional benzimidazole‐derived organocatalyst. Computational and NMR studies support the hydrogen‐bonding activation role of the catalyst and the origin of the stereoselectivity of the process.
Synthesis, Structures, and Optical Properties of Heterasumanenes Containing Group 14 Elements and Their Related Compounds
Authors: Tanikawa Tomoharu , Saito Masaichi , Guo Jing Dong , Nagase Shigeru , Minoura Mao
Published: October 2012

Triphenylenogermole, triphenylenodigermole, and trigermasumanene were prepared by repetitive lithiation of triphenylene followed by introduction of germanium functionalities. This is the first example of a trigermasumanene. Tin congeners were also synthesized and investigated. X‐ray diffraction analysis of trisilasumanene 6, which does not have any substituents on the carbon atoms of the benzene rings, is also demonstrated. The optical properties of trigermasumanene and its derivatives were investigated by UV/Vis and fluorescence spectroscopy. Theoretical calculations were carried out to understand the properties of the thus‐obtained triphenylenometallole derivatives.
Ultratrace Osmium, Ruthenium and Lead in Airborne Particulate Matter: Peak Area as Instrumental Datum to Improve Their Simultaneous Voltammetric Determination
Authors: Locatelli Clinio
Published: October 2012

Peak area as instrumental datum for determining the concentration of metals in solution instead of peak height is proposed for the simultaneous voltammetric determination in particulate matter of ultratrace Os(VIII), Ru(III) and Pb(II), species linked to vehicle emissions. In the case of species present at ultratrace concentration level or having low reversibility degree of the electrodic processes, the employment of peak area, instead of peak current, permits to achieve limits of detection lower even more of one order of magnitude. The method is based on the catalytic current of the Os(VIII)‐, Ru(III)‐ and Pb(II)‐bromate system by differential pulse voltammetry. 0.3 mol L−1 acetate buffer pH 4.5+6.9×10−2 mol L−1 NaBrO3+2.3×10−4 mol L−1 EDTA‐Na2 was employed as the supporting electrolyte. For all the elements, the accuracy, expressed as relative error e%, and the precision, expressed as relative standard deviation sr%, were satisfactory being lower than 6 %. To better validate the analytical procedure, a comparison with spectroscopic (electrothermal atomic absorption spectroscopy, ET‐AAS) is also reported.
Electrochemical Detection of Nitric Oxide: Assessement of Twenty Years of Strategies
Authors: Bedioui Fethi , Griveau Sophie
Published: October 2012

We present an assessment of twenty years of strategies from our group dedicated to the electrochemical detection of nitric oxide NO in solution, for biological applications. We provide a full description of the electrochemical approaches and we summarize the significant research contributions towards the development of sensors. We emphasize the importance of understanding how to improve the performances of the sensors in terms of sensitivity and selectivity. A brief outlook into the future perspectives of the use of multi electrochemical array sensor is presented.
Selective enrichment of catecholamines using iron oxide nanoparticles followed by CE with UV detection
Authors: Lin Tzu‐Hsiang , Lu Chi‐Yu , Tseng Wei‐Lung
Published: October 2012

This study examines the use of unmodified magnetite nanoparticles (Fe3O4 NPs) for selective extraction and enrichment of the catecholamines dopamine (DA), noradrenaline (NE), and adrenaline (E), prior to analysis using capillary electrophoresis with UV detection. Coordination between Fe3+ on‐the‐surface Fe3O4 NPs and the catechol moiety of catecholamines enables Fe3O4 NPs to capture catecholamines from an aqueous solution. We obtained maximum loading of catecholamines on the NP surface by adjusting the pH of the solution to 7.0. In addition, catecholamine loading on the Fe3O4 NPs increased in conjunction with NP concentrations. H3PO4 was found to be efficient for the removal of adsorbed catecholamines on the NP surface. Adding 1.2% poly(diallyldimethylammonium chloride) to the background electrolyte resulted in a baseline separation of the liberated catecholamines within 20 min. Under optimal extraction and separation conditions, the limit of detections at a S/N ratio of 3 for E, NE, and DA were 9, 8, and 10 nM, respectively. Significantly, the combination of a phenylboronate‐containing spin column and the proposed method was successfully applied to the determination of NE and DA in human urine and NE in Portulaca oleracea L. leaves.
Study on the effects of electrolytes and solvents in the determination of quaternary ammonium ions by nonaqueous capillary electrophoresis with contactless conductivity detection
Authors: Buglione Lucia , See Hong Heng , Hauser Peter C.
Published: October 2012

A study on the separation of lipophilic quaternary ammonium cations in NACE coupled with contactless conductivity detection (NACE‐C4D) is presented. The suitability of different salts dissolved in various organic solvents as running electrolytes in NACE‐C4D was investigated. A solvent mixture of methanol/acetonitrile at a ratio of 90%:10% v/v showed the best results. Deoxycholic acid sodium salt as BGE was found to provide exceptional high stability with low baseline noise that leads to highest S/N ratios for the target analytes among all BGEs tested. Under the optimum conditions, capillaries with different internal diameters were examined and an id of 50 μm was found to give best detection sensitivity. The proposed method was validated and showed good linearity in the range from 2.5 to 200 μM, low limits of detection (0.1–0.7 μM) and acceptable reproducibility of peak area (intraday RSD 0.1–0.7%, n = 3; interday RSD 5.9–9.4%, n = 3).
Pencil‐drawn paper supported electrodes as simple electrochemical detectors for paper‐based fluidic devices
Authors: Dossi Nicolò , Toniolo Rosanna , Pizzariello Andrea , Impellizzieri Flavia , Piccin Evandro , Bontempelli Gino
Published: October 2012

A simple procedure for preparing inexpensive paper‐based three‐electrode electrochemical cells is described here. They consist of small circular pads of hydrophilic paper defined by hydrophobic barriers printed on paper with wax‐based ink. The back face of these pads is insulated by thermally laminating a polyethylene layer and working, reference and counter electrodes are drawn on paper by using commercial pencil leads. At last, a controlled volume of sample containing a supporting electrolyte was laid to soak in paper channels. Their performance was evaluated by assaying these devices as both simple cells suitable for recording voltammograms on static samples and low‐cost detectors for flowing systems. Voltammetric tests, conducted by using potassium hexacyanoferrate(II) as model prototype, were also exploited for identifying the brand and softness of graphite sticks enabling paper to be marked with lines displaying the best conductivity. By taking advantage of the satisfactory information thus gained, pencil drawn electrodes were tested as amperometric detectors for the separation of ascorbic acid and sunset yellow, which were chosen as prototype electroactive analytes because they are frequently present concomitantly in several food matrices, such as soft drinks and fruit juices. This separation was performed by planar thin layer chromatography conducted on microfluidic paper‐based devices prepared by patterning on filter paper two longitudinal hydrophobic barriers, once again printed with wax‐based ink. Factors affecting both separation and electrochemical detection were examined and optimised, with best performance achieved by using a 20 mM acetate running buffer (pH 4.5) and by applying a detection potential of 0.9 V. Under these optimum conditions, the target analytes could be separated and detected within 6 min. The recorded peaks were well separated and characterized by good repeatability and fairly good sensitivity, thus proving that this approach is indeed suitable for rapidly assembling inexpensive and reliable electrochemical detectors for flow analysis systems.
Emission profile and predictive model for high sulfur low rank coals used in carbonization and combustion units
Authors: Khare Puja , Sarmah M. , Das T. , Sahu O.P. , Baruah B.P.
Published: October 2012

In the present investigation, the characteristics of emissions (PM2.5, PM10 and suspended particulate matter), NO2, SO2, and NH3 during coal utilization processes (carbonization and combustion) and mining are discussed. Emissions were also compared with those released from the combustion of wood along with the background concentration. Morphological characterization, organic functionality, elemental, and ionic composition of particulate samples was also done. The study shows that the gases released depend upon the fuel utilization processes and their precursor concentrations in fuel. The size distribution and ionic composition of particles depend upon the fuel types and processes of particulate formation, i.e., nucleation and agglomeration. Distribution of element in coal and their association control the emission of particulate bound elements. Principal component analysis applied for the prediction of emission behaviors of coal during combustion and carbonization which provide the relation between the coal properties and emissions. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1284–1295, 2013
A simple ground‐motion prediction model for cumulative absolute velocity and model validation
Authors: Du Wenqi , Wang Gang
Published: October 2012

Cumulative absolute velocity (CAV) is an important ground motion intensity measure used in seismic hazard analysis. Based on the Next Generation Attenuation strong motion database, a simple ground‐motion prediction equation is proposed for the geometric mean of as‐recorded horizontal components of CAVs using mixed regression analysis. The proposed model employs only four parameters and has a simple functional form. Validation tests are conducted to compare the proposed model with the recently developed Campbell–Bozorgnia (CB10) model using subsets of the strong motion database, as well as several recent earthquakes that are not used in developing the model. It is found that the predictive capability of the proposed model is comparable with the CB10 model, which employs a complex functional form and more parameters. The study also corroborates previous findings that CAV has higher predictability than other intensity measures such as the peak ground acceleration. The high predictability of CAV warrants the use of the proposed simple model as an alternative in seismic hazard analysis. Copyright © 2012 John Wiley & Sons, Ltd.
Spatial and developmental heterogeneity of calcium signaling in olfactory ensheathing cells
Authors: Thyssen Anne , Stavermann Maren , Buddrus Kristina , Doengi Michael , Ekberg Jenny A. , St John James A. , Deitmer Joachim W. , Lohr Christian
Published: October 2012

Olfactory ensheathing cells (OECs) are specialized glial cells in the mammalian olfactory system supporting growth of axons from the olfactory epithelium into the olfactory bulb. OECs in the olfactory bulb can be subdivided into OECs of the outer nerve layer and the inner nerve layer according to the expression of marker proteins and their location in the nerve layer. In the present study, we have used confocal calcium imaging of OECs in acute mouse brain slices and olfactory bulbs in toto to investigate physiological differences between OEC subpopulations. OECs in the outer nerve layer, but not the inner nerve layer, responded to glutamate, ATP, serotonin, dopamine, carbachol, and phenylephrine with increases in the cytosolic calcium concentration. The calcium responses consisted of a transient and a tonic component, the latter being mediated by store‐operated calcium entry. Calcium measurements in OECs during the first three postnatal weeks revealed a downregulation of mGluR1 and P2Y1 receptor‐mediated calcium signaling within the first 2 weeks, suggesting that the expression of these receptors is developmentally controlled. In addition, electrical stimulation of sensory axons evoked calcium signaling via mGluR1 and P2Y1 only in outer nerve layer OECs. Downregulation of the receptor‐mediated calcium responses in postnatal animals is reflected by a decrease in amplitude of stimulation‐evoked calcium transients in OECs from postnatal days 3 to 21. In summary, the results presented reveal striking differences in receptor responses during development and in axon–OEC communication between the two subpopulations of OECs in the olfactory bulb. © 2012 Wiley Periodicals, Inc.
The delirium experience: what is the effect on patients, relatives and staff and what can be done to modify this?
Authors: Partridge Judith SL , Martin Finbarr C , Harari Danielle , Dhesi Jugdeep K
Published: October 2012

Background

Delirium is a common clinical syndrome with significant associated mortality, morbidity and financial cost. Less is understood about the experience of delirium for the patient, their family and staff involved in their care.

Objective

This synthesis draws on qualitative and quantitative literature examining different populations (patients, relatives and staff) in different clinical settings (intensive care units, surgery and hospice care) to provide a clinical summary of the delirium experience from the perspective of patients, relatives and staff.

Design

A literature search was conducted in Ovid, MEDLINE, Embase, PsychINFO, British Nursing Index and Archive and PubMed between 1980 and 2011 using the terms ‘delirium’ combined with ‘distress’, ‘recall’, ‘anxiety’, ‘depression’, ‘PTSD’, ‘experience’ and ‘patient education’. Articles were restricted to English language only.

Results

Evidence suggests that some patients recall delirium and that recollections are generally distressing. Distress may be greater in relatives witnessing delirium and is also reported in professional staff. This distress may result in longer‐term psychological sequelae. Remedial action, such as explanatory information to patients and their families, may reduce distress and psychological morbidity.

Conclusions

A better understanding of the experience and psychological consequences of delirium will inform the development of appropriate methods of providing support and information to those at risk of delirium and their families or carers. Copyright © 2012 John Wiley & Sons, Ltd.
Hemorrhagic events in hepatocellular carcinoma patients treated with antiangiogenic therapies
Authors: Duffy Austin , Wilkerson Julia , Greten Tim F.
Published: October 2012

The presence of cirrhosis increases the potential risk of hemorrhage for patients with hepatocellular carcinoma (HCC). We evaluated the relative risk for hemorrhage in patients with HCC treated with antiangiogenic agents. We performed a systematic review and meta-analysis of antiangiogenic studies in HCC from 1995 to 2011. For nonrandomized studies we compared bleeding risk with other HCC single-arm studies that did not include an antiangiogenic agent. To separate disease-specific factors we also performed a comparison analysis with renal cell cancer (RCC)) studies that evaluated sorafenib. Sorafenib was associated with increased bleeding risk compared to control for all grade bleeding events (odds ratio [OR] 1.77; 95% confidence interval [CI] 1.04, 3.0) but not grade 3–5 events in both HCC and RCC (OR 1.46; 95% CI 0.9, 2.36;

P

= 0.45). When comparing the risk of bleeding in single-arm phase 2 studies evaluating antiangiogenic agents, this risk for all events (OR 4.34; 95% CI 2.16, 8.73) was increased compared to control.

Conclusion:

This analysis of both randomized and nonrandomized studies evaluating an antiangiogenic agent in HCC showed that whereas the use of sorafenib was associated with an increased risk of bleeding in HCC, this was primarily for lower-grade events and similar in magnitude to the risk encountered in RCC. (Hepatology 2013)
Isolated human and animal stratum corneum as a partial model for the 15 steps of percutaneous absorption: emphasizing decontamination, part II
Authors: Hui Xiaoying , Lamel Sonia , Qiao Peter , Maibach Howard I.
Published: October 2012

Cutaneously directed chemical warfare agents can elicit significant morbidity and mortality. The optimization of prophylactic and therapeutic interventions counteracting these agents is crucial, and the development of decontamination protocols and methodology of post dermal exposure risk assessments would be additionally applicable to common industrial and consumer dermatotoxicants. Percutaneous (PC) penetration is often considered a simple one‐step diffusion process but presently consists of at least 15 steps. The systemic exposure to an agent depends on multiple factors and the second part of this review covers absorption and excretion kinetics, wash and rub effects, skin substantivity and transfer, among others. Importantly, the partitioning behavior and diffusion through the stratum corneum (SC) of a wide physicochemical array of compounds shows that many compounds have approximately the same diffusion coefficient which determines their percutaneous absorption in vivo. After accounting for anatomical variation of the SC, the penetration flux value of a substance depends mainly on its SC/vehicle partition coefficient. Additionally, the SC acts as a ‘reservoir’ for topically applied molecules, and tape stripping methodology can quantify the remaining chemical in the SC which can predict the total molecular penetration in vivo. The determination of ideal decontamination protocols is of utmost importance to reduce morbidity and mortality. However, even expeditious standard washing procedures post dermal chemical exposure often fails to remove chemicals. The second part of this overview continues to review percutaneous penetration extending insights into the complexities of penetration, decontamination and potential newer assays that may be of practical importance. Copyright © 2012 John Wiley & Sons, Ltd.
Are your cash transactions protected?
Authors: Byington J. Ralph , McGee Jo Ann
Published: October 2012

Cash is the most commonly targeted asset by white‐collar crime fraudsters. How well are your company's cash transactions protected? What are the main types of cash fraud schemes that you must guard against? And what steps should you be taking right now? © 2012 Wiley Periodicals, Inc.
Synthesis, Photophysical Properties, and Antimicrobial Activity of Novel Styryl Colorants Derived from 7‐Methoxy‐1,4‐diphenethyl‐1,2,3,4‐tetrahydroquinoxaline‐6‐carbaldehyde
Authors: Jarag K. J. , Jagtap A. R. , Borse B. N. , Shukla S. R. , Shankarling G. S.
Published: October 2012

The novel 1,4‐diphenethyl‐1,2,3,4‐tetrahydro‐7‐methoxyquinoxalin‐6‐carbaldehyde was synthesized by reductive alkylation of 6‐methoxy quinoxaline with phenyl acetic acid and was further subjected to Knoevenagel condensation with various active methylene compounds to synthesize novel styryl colorants. Photophysical properties of styryl colorants were studied using UV–visible and fluorescence spectroscopy. These colorants displayed orange to violet hue and showed fluorescence emission maxima in the region of 560–640 nm, and displayed a large Stokes shift (85–104 nm). Compounds were subjected to thermogravimetric analysis which showed excellent stability up to 310°C. These styryl compounds were evaluated for their antimicrobial study as antifungal against Candida albicans C. albicans and Aspergillus niger and antibacterial against Escherichia coli and Staphylococcus aureus. The results revealed good antimicrobial activity against tested organisms. The synthesized chromophores were characterized using elemental analysis, FTIR, 13C‐NMR and 1H‐NMR spectroscopy and mass spectrometry.
Asymmetric Synthesis of Both Enantiomers of Protected 5‐Hydroxynorvaline by Hetero‐Diels‐Alder Addition of ethyl 2‐Nitrosoacrylate to (R)‐ and (S)‐1‐Phenylbutyl Vinyl Ether
Authors: Massen Zoe S. , Gallos John K.
Published: October 2012

Both enantiomers of protected 5‐hydroxynorvaline were prepared by hetero‐Diels‐Alder addition of ethyl 2‐nitrosoacrylate to readily available (R)‐ and (S)‐1‐phenylbutyl vinyl ether and a further three‐step manipulation. Attempted synthesis of (±)‐vigabatrin from protected (±)‐5‐hydroxynorvaline was unsuccessful.
Synthesis and Biological Activity of Some New Pyrazole Copper(II) Complexes
Authors: Maruoka Hiroshi , Nishida Sho , Kashige Nobuhiro , Yoshimura Yuki , Omori Masahiko , Tomita Ryoko , Masumoto Eiichi , Okabe Fumi , Miake Fumio , Yamagata Kenji , Fujioka Toshihiro
Published: October 2012

As a part of systematic investigation of synthesis and biologically active compounds of pyrazole derivatives containing transition metal, several new pyrazole copper(II) complexes 3a−f were synthesized from pyrazole sodium salts 2a−f, which were produced from spiro‐pyrazoles 1a−f and sodium hydride by a ring‐opening reaction. All the synthesized compounds were characterized by spectroscopic analysis. Pyrazole copper(II) complexes 3a−d and 3f exhibited high DNA cleavage activity in vitro. Furthermore, compounds 3a−f were tested for their growth inhibitory activity in A549 lung cancer, B16F10 murine melanoma, and HeLa human uterine carcinoma cells. Compounds 3c,d displayed moderate B16F10 and HeLa inhibitory activity levels (3c: IC50 = 45 μM in B16F10 cells and 34 μM in HeLa cells, 3d: IC50 = 50 μM in B16F10 cells and 32 μM in HeLa cells).
Zwitterionic‐Type Molten Salt‐Catalyzed Multicomponent Reactions: One‐Pot Synthesis of Substituted Imidazoles Under Solvent‐Free Conditions
Authors: Rahman Matiur , Bagdi Avik Kr. , Kundu Dhiman , Majee Adinath , Hajra Alakananda
Published: October 2012

4‐(1‐Imidazolium) butane sulfonate is an excellent catalyst for the synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetrasubstituted imidazoles through the condensation of 1,2‐dicarbonyl compounds, aldehydes, and ammonium acetate or amine via multicomponent condensation strategy under solvent‐free conditions. The key advantages of this process are high yields, reusability of catalyst, environmental friendliness, easy work‐up and purification of products by nonchromatographic methods.
A Facile Solvent‐Free Synthesis of Chiral Oxazolidinone Derivatives Catalyzed by MgI2 Etherate: An Approach to Enantiopure Synthesis of Linezolid
Authors: Zhang Xingxian , Zhao Chengfeng , Gu Yue
Published: October 2012

A highly efficient and stereoselective cycloaddition of aryl isocyanates with chiral oxiranes catalyzed by MgI2 etherate under solvent‐free conditions was developed to prepare the chiral oxazolidinone derivatives. This methodology has been applied into the practical synthesis of antibacterial drug linezolid.
Synthesis of Pyrazolo[3,4‐b]pyridin‐6‐ones
Authors: Komarova Elena S. , Makarov Vadim A. , Granik Vladimir G. , Párkányi Cyril
Published: October 2012

The procedures for the synthesis of substituted pyrazolo[3,4‐b]pyridine‐6‐ones and some of their properties are reviewed.
Facile and improved synthesis of [11C]Me‐QNB
Authors: Gómez‐Vallejo Vanessa , González‐Esparza Mikel , Llop Jordi
Published: October 2012

[11C]Me‐QNB is a muscarinic acetylcholinergic receptor antagonist that has been used for the assessment of myocardial muscarinic receptors density in different cardiovascular pathologies. In the current technical note, we report a facile, highly efficient and fully automated method for the preparation of this radiotracer. The radiosynthesis was performed by reaction of [11C]CH3I with the desmethylated precursor (QNB) at room temperature using the captive solvent method. Excellent radiochemical yield (91.1 ± 2.4%, decay‐corrected) and radiochemical purity (>99.5%), and good specific activity (137 ± 5 GBq/µmol) were obtained when the purification was performed by reverse phase HPLC in overall synthesis time <31 min. Purification using solid‐phase extraction offered lower radiochemical yield (27.6 ± 3.1%, decay‐corrected) and radiochemical purity (>95%) but higher specific activity (244 ± 18 GBq/µmol) in shorter reaction times (<21 min). These results, especially concerning radiochemical yield, significantly improve those previously reported in which the reaction was performed in a vial and the purification step was based on ionic chromatography.
Scale considerations in using diatoms as indicators of sea‐level change: lessons from Alaska
Authors: Watcham Emma P. , Shennan Ian , Barlow Natasha L. M.
Published: October 2012

This paper assesses variations in quantitative reconstructions of late Holocene relative sea‐level (RSL) change arising from using modern diatom datasets from different spatial scales, applied to case studies from Alaska. We investigate the implications of model choice in transfer functions using local‐, sub‐regional‐ and regional‐scale modern training sets, and produce recommendations on the creation and selection of modern datasets for reconstructing RSL change over Holocene timescales in tidal marsh environments comparable with those in Alaska. We show that regional modern training sets perform best in terms of providing fossil samples with good modern analogues, and in producing reconstructions that most closely match observations, where these are available. Local training sets are frequently insufficient to provide fossil samples with good modern analogues and may over‐estimate the precision of RSL reconstructions. This is particularly apparent when reconstructing RSL change for periods beyond the last century. For reconstructing RSL change we recommend using regional modern training sets enhanced by local samples. Copyright © 2012 John Wiley & Sons, Ltd.
Hollow‐fiber liquid‐phase microextraction and gas chromatography‐mass spectrometry of barbiturates in whole blood samples
Authors: Menck Rafael Almeida , de Lima Diógenes Saulo , Seulin Saskia Carolina , Leyton Vilma , Pasqualucci Carlos Augusto , Muñoz Daniel Romero , Osselton Michael David , Yonamine Mauricio
Published: October 2012

Here, we present a method for measuring barbiturates (butalbital, secobarbital, pentobarbital, and phenobarbital) in whole blood samples. To accomplish these measurements, analytes were extracted by means of hollow‐fiber liquid‐phase microextraction in the three‐phase mode. Hollow‐fiber pores were filled with decanol, and a solution of sodium hydroxide (pH 13) was introduced into the lumen of the fiber (acceptor phase). The fiber was submersed in the acidified blood sample, and the system was subjected to an ultrasonic bath. After a 5 min extraction, the acceptor phase was withdrawn from the fiber and dried under a nitrogen stream. The residue was reconstituted with ethyl acetate and trimethylanilinium hydroxide. An aliquot of 1.0 μL of this solution was injected into the gas chromatograph/mass spectrometer, with the derivatization reaction occurring in the hot injector port (flash methylation). The method proved to be simple and rapid, and only a small amount of organic solvent (decanol) was needed for extraction. The detection limit was 0.5 μg/mL for all the analyzed barbiturates. The calibration curves were linear over the specified range (1.0 to 10.0 μg/mL). This method was successfully applied to postmortem samples (heart blood and femoral blood) collected from three deceased persons previously exposed to barbiturates.
Online desorption of molecularly imprinted stir bar sorptive extraction coupled to high performance liquid chromatography for the trace analysis of triazines in rice
Authors: Zhong Qisheng , Hu Yufei , Hu Yuling , Li Gongke
Published: October 2012

Based on a special homemade interface, the molecularly imprinted stir bar sorptive extraction was coupled to high performance liquid chromatography for the online desorption and analysis. During desorption, the analytes desorbed from stir bar were delivered to a sample loop and then was introduced into liquid chromatography for further analysis. The online desorption and introduction processes were real‐time monitored by the ultraviolet detector of the liquid chromatography system. In this way, the method sensitivity and reproducibility was improved for the introduction timing of the desorption solvent with greatest concentration of the target analytes was accurately controlled. To demonstrate the feasibility of the method, terbuthylazine imprinted stir bar was synthesized and used for the analysis of nine triazines in rice. Under the optimized conditions, limits of detection of 0.02–0.11 μg/L and precision within 4.3–7.2% were achieved. The new method was compared with other two traditional offline desorption procedures, i.e. ultrasonic‐assisted desorption and static thermal desorption. The comparison results showed that the proposed method is accurate, precise, fast, and suitable for the trace analysis of complex samples.
Establishment of a search library about benzylisoquinoline alkaloids based on selective separation on the binaphthyl column and standard analysis on C18 column
Authors: Liu Qiaoxia , Zhou Binbin , Wang Xinliang , Ke Yanxiong , Jin Yu , Yin Lihui , Liang Xinmiao
Published: October 2012

A search library about benzylisoquinoline alkaloids was established based on preparation of alkaloid fractions from Rhizoma coptidis, Cortex phellodendri, and Rhizoma corydalis. In this work, two alkaloid fractions from each herbal medicine were first prepared based on selective separation on the “click” binaphthyl column. And then these alkaloid fractions were analyzed on C18 column by liquid chromatography coupled with tandem mass spectrometry. Many structure‐related compounds were included in these alkaloids fractions, which led to easy separation and good MS response in further work. Therefore, a search library of 52 benzylisoquinoline alkaloids was established, which included eight aporphine, 19 tetrahydroprotoberberine, two protopine, two benzyltetrahydroisoquinoline, and 21 protoberberine alkaloids. The information of the search library contained compound names, structures, retention times, accurate masses, fragmentation pathways of benzylisoquionline alkaloids, and their sources from three herbal medicines. Using such a library, the alkaloids, especially those trace and unknown components in some herbal medicine could be accurately and quickly identified. In addition, the distribution of benzylisoquinoline alkaloids in the herbal medicines could be also summarized by searching the source samples in the library.
Sequential dispersive liquid–liquid microextraction for the determination of aryloxyphenoxy‐propionate herbicides in water
Authors: Li Songqing , Gao Peng , Zhang Jiaheng , Li Yubo , Peng Bing , Gao Haixiang , Zhou Wenfeng
Published: October 2012

A novel dispersive liquid–liquid microextraction (DLLME) method followed by HPLC analysis, termed sequential DLLME, was developed for the preconcentration and determination of aryloxyphenoxy‐propionate herbicides (i.e. haloxyfop‐R‐methyl, cyhalofop‐butyl, fenoxaprop‐P‐ethyl, and fluazifop‐P‐butyl) in aqueous samples. The method is based on the combination of ultrasound‐assisted DLLME with in situ ionic liquid (IL) DLLME into one extraction procedure and achieved better performance than widely used DLLME procedures. Chlorobenzene was used as the extraction solvent during the first extraction. Hydrophilic IL 1‐octyl‐3‐methylimidazolium chloride was used as a dispersive solvent during the first extraction and as an extraction solvent during the second extraction after an in situ chloride exchange by bis[(trifluoromethane)sulfonyl]imide. Several experimental parameters affecting the extraction efficiency were studied and optimized with the design of experiments using MINITAB® 16 software. Under the optimized conditions, the extractions resulted in analyte recoveries of 78–91%. The correlation coefficients of the calibration curves ranged from 0.9994 to 0.9997 at concentrations of 10–300, 15–300, and 20–300 μg L−1. The relative SDs (n = 5) ranged from 2.9 to 5.4%. The LODs for the four herbicides were between 1.50 and 6.12 μg L−1.
Mechanism of improved antibody aggregate separation in polyethylene glycol‐modulated cation exchange chromatography
Authors: Kluters Simon , Neumann Sebastian , von Hirschheydt Thomas , Grossmann Adelbert , Schaubmar Andreas , Frech Christian
Published: October 2012

Ion‐exchange chromatography is used in biopharmaceutical downstream processes to reduce product‐related impurity levels. Because protein aggregate levels can be considered as a critical quality attribute, the removal of aggregated protein species is of primary importance. The addition of polyethylene glycol (PEG) to the mobile phase in ion‐exchange chromatography was found to significantly improve the chromatographic separation of monomers from aggregates. In this work, linear gradient elution experiments with monomeric and aggregated samples of a monoclonal antibody were performed on a strong cation exchange resin at different PEG concentrations to investigate the underlying effects responsible for the observed selectivity improvement. PEG is well known to be excluded from a surface layer volume around the protein and the stationary phase; thus, enhancing adsorption of the preferentially hydrated protein to the hydrated stationary phase. The exclusion volume depends on the accessible surface area of the protein leading to a stronger influence of PEG on larger protein species and thus an improved separation of monomer and aggregates. This hypothesis could be consolidated comparing the distribution equilibrium in PEG solution to that in water by calculating equilibrium constants and transfer free energies using the chromatographic data from the linear gradient elution experiments performed at different pH values.
Effect of dicationic gemini surfactants 16–s‐16 (s = 4, 5, 6) on the ninhydrin‐dipeptide (glycyl‐tyrosine) reaction
Authors: Akram Mohd. , Kumar Dileep , Kabir‐Ud‐Din
Published: October 2012

The effect of dicationic gemini surfactants H33C16(CH3)2N+‐(CH2)s‐N+(CH3)2 C16H33, 2Br− (s= 4, 5, 6) on the reaction of a dipeptide glycyl–tyrosine (Gly–Tyr) with ninhydrin has been studied spectrophotometrically at 70°C and pH 5.0. The reaction follows first‐ and fractional‐order kinetics, respectively, in [Gly–Tyr] and [ninhydrin]. The gemini surfactant micellar media are comparatively more effective than their single chain–single head counterpart cetyltrimethylammonium bromide (CTAB) micelles. Whereas typical rate constant (kΨ) increase and leveling‐off regions, just like CTAB, are observed with geminis, the latter produces a third region of increasing kΨ at higher concentrations. This subsequent increase is ascribed to the change in the micellar morphology of the geminis. The pseudophase model of micelles was used to quantitatively analyze the kΨ − [gemini] data, wherein the micellar‐binding constants KS for [Gly–Tyr] and KN for ninhydrin were evaluated. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 800–809, 2012
Securely Joining Plastic Components
Authors: Brunnecker Frank
Published: October 2012

The transmission laser welding of plastics is a well‐established industrial joining method whose reliability makes it particularly suitable for applications where very high weld seam quality is specified. A number of quality assurance methods are available when using this technology to safeguard the specifications. These quality assurance methods are suitable for implementing a zero‐error strategy, under very economically attractive conditions.
Chain Transfer to 2‐Mercaptoethanol in Methacrylic Acid Polymerization in Aqueous Solution
Authors: Wittenberg Nils F. G. , Buback Michael , Stach Marek , Lacík Igor
Published: October 2012

The chain‐transfer constant, CS = ktr/kp, of 2‐mercaptoethanol (ME) for methacrylic acid (MAA) polymerization in aqueous solution has been measured at MAA concentrations between 5 and 30 wt% to be 0.12 ± 0.01 at 50 °C. Analysis has been carried out via both the Mayo and the chain‐length distribution (CLD) methods. No change of CS with monomer concentration is observed. The chain‐transfer rate coefficient, ktr, thus exhibits the same strong dependence on monomer concentration as the propagation rate coefficient, kp.
Assessment of the relevance of the antibiotic 2‐amino‐3‐(oxirane‐2,3‐dicarboxamido)‐propanoyl‐valine from Pantoea agglomerans biological control strains against bacterial plant pathogens
Authors: Sammer Ulrike F. , Reiher Katharina , Spiteller Dieter , Wensing Annette , Völksch Beate
Published: October 2012

The epiphyte Pantoea agglomerans 48b/90 (Pa48b) is a promising biocontrol strain against economically important bacterial pathogens such as Erwinia amylovora. Strain Pa48b produces the broad‐spectrum antibiotic 2‐amino‐3‐(oxirane‐2,3‐dicarboxamido)‐propanoyl‐valine (APV) in a temperature‐dependent manner. An APV‐negative mutant still suppressed the E. amylovora population and fire blight disease symptoms in apple blossom experiments under greenhouse conditions, but was inferior to the Pa48b wild‐type indicating the influence of APV in the antagonism. In plant experiments with the soybean pathogen Pseudomonas syringae pv. glycinea both, Pa48b and the APV‐negative mutant, successfully suppressed the pathogen. Our results demonstrate that the P. agglomerans strain Pa48b is an efficient biocontrol organism against plant pathogens, and we prove its ability for fast colonization of plant surfaces over a wide temperature range.