bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation into the suitability of capillary tubes for microcrystalline testing
Authors: Elie Leonie E. , Baron Mark G. , Croxton Ruth S. , Elie Mathieu P.
Published: May 2012

A comparison between microcrystalline tests performed on microscope slides and flat capillary tubes with inner diameters ranging from 0.1 to 0.7 mm was carried out to explore the appropriateness of tubes for rapid testing of suspected drugs of abuse in the laboratory as well as in the field. Tests for mephedrone, cocaine, and phencyclidine were chosen as examples to investigate the handling of the capillary tubes, the influence on crystal habit, size, and the effects on the limit of detection. Image stacking software was used to increase the depth of field of micrographs taken from developed microcrystals greatly enhancing the interpretability even months after carrying out the microcrystalline test.

Additionally, the potential of seeding capillary tubes with a reagent was studied. Pre‐treatment of tubes would allow microcrystalline tests to be carried out quicker and anywhere without the necessity of taking along expensive and hazardous reagents. The sealing of capillary tubes containing developed microcrystalline tests in order to preserve results for a long period of time was successfully done by applying paraffin wax to the open ends.

Finally, it was concluded that capillary tubes are suitable vessels for performing microcrystalline tests. The increased portability of the improved set‐up allows tests to be safely executed outside laboratories without impairing the quality of the result. Findings were applied to six legal high samples purchased online between May and August 2011. The active ingredients like MDAI as well as cutting agents like caffeine were successfully identified using the microcrystalline test technique in capillary tubes. Copyright © 2012 John Wiley & Sons, Ltd.
A genetic polymorphism in the sex‐linked ATP5A1 gene is associated with individual fitness in Ovenbirds (Seiurus aurocapilla)
Authors: Toms Judith D. , Eggert Lori S. , Arendt Wayne J. , Faaborg John
Published: May 2012

While testing genetic sexing techniques in Ovenbirds (Seiurus aurocapilla), we found a genetic polymorphism in the ATP5A1 gene in 38% of individuals. The Z′ allele included changes in both intronic and exonic portions of the sequenced region, but there was no evidence that this changed the resulting ATP synthase product. Males that had one or more copies of this allele had higher relative body mass (mass corrected for size) than other genotypes. This allele was unrelated to stable isotope signatures, and so was not a useful predictor of latitude within the eastern portion of the Ovenbird breeding range. Future studies are needed to determine whether this polymorphism may be a useful geographic marker. This study is the first to link polymorphisms in the sex‐linked ATP5A1 gene with fitness effects.
Effects of leaf hydrophobicity and water droplet retention on canopy storage capacity
Authors: Holder Curtis D.
Published: May 2012

Canopy storage capacity is influenced by several variables, including canopy surface area, canopy architecture, and wind. Different species with the same canopy area, but with differences in leaf hydrophobicity and water droplet retention, may produce different values of canopy storage capacity. The objective of this study was to investigate if leaf hydrophobicity and water droplet retention are additional influences on canopy storage capacity. Specifically, this study tested the hypothesis that species with the highest leaf hydrophobicity and the lowest water droplet retention had the lowest canopy storage capacity on a per leaf area basis. Seven tree species from Colorado, United States were selected for experimentation. Five branches from each species were lopped, positioned under a rainfall simulator, and connected to a balance to record the mass gain of the branches by rainfall interception during 17 min of rainfall simulation. Each branch was destructively sampled following rainfall simulation to calculate the leaf and woody surface areas. The rank order of leaf surface storages at canopy storage capacity for each species corresponded to the rank order of leaf hydrophobicity and water droplet retention for each species. Species with the highest leaf surface storage had the lowest leaf hydrophobicity and the lowest water droplet retention. The significance of leaf hydrophobicity and water droplet retention as variables that influence canopy storage capacity is a largely unexplored topic in ecohydrology. Copyright © 2012 John Wiley & Sons, Ltd.
Mechanics of interrill erosion with wind‐driven rain
Authors: Erpul Gunay , Gabriels Donald , Norton L. Darrell , Flanagan Dennis C. , Huang Chi‐hua , Visser Saskia M.
Published: May 2012

The vector physics of wind‐driven rain (WDR) differs from that of wind‐free rain, and the interrill soil detachment equations in the Water Erosion Prediction Project (WEPP) model were not originally developed to deal with this phenomenon. This article provides an evaluation of the performance of the interrill component of the WEPP model for WDR events. The interrill delivery rates were measured in the wind tunnel facility of the International Center for Eremology (ICE), Ghent University, Belgium with an experimental setup to study different raindrop impact velocity vectors. Synchronized wind and rain simulations with wind velocities of 6, 10 and 14 m s–1 were applied to a test surface placed on windward and leeward slopes of 7, 15 and 20%. Since both rainfall intensity and raindrop impact velocity varied greatly depending on differences in the horizontal wind velocity under WDRs, the resultant kinetic energy flux (KEr, in J m–2 s–1) was initially used in place of the WEPP model intensity term in order to incorporate the effect of wind on impact velocity and frequency of raindrops. However, our results showed only minor improvement in the model predictions. For all research data, the model Coefficients of Determination (r2) were 0·63 and 0·71, when using the WEPP and the KEr approaches, respectively. Alternately, integrating the angle of rain incidence into the model by vectorally partitioning normal kinetic energy flux (KErn, in J m–2 s–1) from the KEr greatly improved the model's ability to estimate the interrill sediment delivery rates (r2 = 0·91). This finding suggested that along with the fall trajectory of wind‐driven raindrops with a given frequency, raindrop velocity and direction at the point of impact onto the soil surface provided sufficient physical information to improve WEPP sediment delivery rate predictions under WDR. Copyright © 2012 John Wiley & Sons, Ltd.
Runoff and sediment yield from land under various uses in a Mediterranean mountain area: long‐term results from an experimental station
Authors: Nadal‐Romero Estela , Lasanta Teodoro , García‐Ruiz José M.
Published: May 2012

In this study we analyzed runoff and sediment yield from land under various traditional and current land uses in Mediterranean mountain areas, using long‐term data from an experimental station in the Aísa Valley, Central Spanish Pyrenees. Monitoring at this station has provided 20 years of data that can help explain the hydrological and geomorphological changes that have been observed at larger spatial scales, and also the changes that have occurred to some of the most characteristic landscapes of the Mediterranean middle mountains. In spite of the problems associated with the use of small experimental plots, the results obtained are consistent with other studies in the Mediterranean region, and confirm the strong influence of land use changes on runoff generation and sediment yield. The results indicate that: (i) cereal cultivation on steep slopes (both alternating cereal cultivation and fallow on sloping fields and shifting agriculture on the steepest slopes) represents a major problem for soil conservation. This explains the occurrence throughout the Mediterranean mountains of many degraded hillslopes, which show evidence of sheet wash erosion, rilling, gullying and shallow landsliding; (ii) farmland abandonment has led to a marked reduction in runoff and sediment yield as a consequence of rapid plant recolonization, particularly by dense shrubs; (iii) the natural transformation of abandoned fields into grazing meadows has reduced runoff and sediment yield. Land use trends in the Mediterranean mountains are mainly characterized by generalized farmland abandonment and a decrease in livestock pressure. From a hydrological and geomorphological point of view the main consequences have been a reduction in overland flow from the hillslopes, and a reduction in sediment sources, with differences up to one order of magnitude in sediment yield from dense shrub cover and grazing meadow areas compared with areas under shifting agriculture. Copyright © 2012 John Wiley & Sons, Ltd.
Treatment of the small time instability in the finite element analysis of fluid structure interaction problems
Authors: Afrasiab Hamed , Movahhedy Mohammad R.
Published: May 2012

In this paper, the fluid–structure interaction problem in mechanical systems in which a high frequency vibrating solid structure interacts with the surrounding fluid flow is considered. Such a situation normally appears in many microelectromechanical systems like a wide variety of microfluidic devices. A different implementation of the residual‐based variational multiscale flow method is employed within the arbitrary Lagrangian–Eulerian formulation. The combination of the variational multiscale method with appropriate stabilization parameters is used to handle the so‐called small time step instability in the finite element analysis of the fluid part in the coupled fluid–structure interaction problem. The capability of the employed approach has been demonstrated through finite element study of a benchmark example and FEM simulation of two different mechanical micropumping devices. High frequency vibrations of the solid membrane are used to derive the fluid flow in these micropumps. Results of FEM simulations are shown to be in good agreement with available experimental data.Copyright © 2012 John Wiley & Sons, Ltd.
Depressive symptoms in older people with metabolic syndrome: is there a relationship with inflammation?
Authors: Viscogliosi Giovanni , Andreozzi Paola , Chiriac Iulia Maria , Cipriani Elisa , Servello Adriana , Marigliano Benedetta , Ettorre Evaristo , Marigliano Vincenzo
Published: May 2012

Objective

To investigate if there is a higher prevalence of depressive symptoms in older people with metabolic syndrome (MetS) compared with those without and whether dedpressive symptoms are independently associated to MetS and its single components and to the inflammatory markers.

Methods

Physical parameters, standard blood analytes, high sensitivity C‐reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) were assessed. Fifteen‐item Geriatric Depression Scale and mini mental state examination (MMSE) were administered.

Results

One hundred thirty‐three subjects were enrolled. MetS patients (57) exhibited higher prevalence of depressive symptoms (p < 0.0001), worse cognitive function (p < 0.0001), and higher levels of ESR and hsCRP were higher (p < 0.0001). The univariate analysis showed a linear strong correlation of depressive symptoms (p < 0.0001) with the MMSE score (r = −0.422), body mass index (r = 0.414), MetS (r = 0.582), number of MetS components (r = 0.663), fasting blood glucose (r = 0.565), ESR (r = 0.565), hsCRP (r = 0.745), central obesity (r = 0.269; p = 0.002), and high‐density lipoprotein cholesterol (r = −0.241; p = 0.005). However, the multivariate analysis showed that only age (B = −0.093; p = 0.032), MetS (B = 1.446; p = 0.025), fasting blood glucose (B = 0.039; p = 0.005), and hsCRP (B = 7.649; p < 0.0001) were independently associated with depressive symptoms.

Conclusions

MetS and inflammation are independently associated with depressive symptoms in older people. Inflammation may explain cognitive decline too. Further investigations are needed to better understand the direction of these associations and to determine whether these can be reversible. Copyright © 2012 John Wiley & Sons, Ltd.
Comparison of entorhinal cortex atrophy between early‐onset and late‐onset Alzheimer's disease using the VSRAD, a specific and sensitive voxel‐based morphometry
Authors: Shibuya Yuzuru , Kawakatsu Shinobu , Hayashi Hiroshi , Kobayashi Ryota , Suzuki Akihito , Sato Chikako , Otani Koichi
Published: May 2012

Background

The most characteristic symptom of Alzheimer's disease (AD) is episodic memory impairment, which is closely associated with atrophy of the entorhinal cortex. Meanwhile, atypical symptoms are more frequent in early‐onset AD than in late‐onset AD, suggesting that the former subtype has less atrophy in the entorhinal cortex. Therefore, we investigated whether the degree of atrophy in the entorhinal cortex is different between the two subtypes of AD using the voxel‐based specific regional analysis system for AD (VSRAD) targeting this region.

Methods

The subjects consisted of 198 patients with AD. They were divided into two groups, that is, the early‐onset AD group with the onset under age 65 years (n = 18) and the late‐onset AD group with the onset at age 65 years or over (n = 180). The degree of atrophy in the entorhinal cortex was quantified by application of the VSRAD to magnetic resonance imaging data, and a Z‐score >2 was defined as significant atrophy according to previous studies.

Results

The early‐onset group had significantly lower Z‐scores than the late‐onset group (mean ± SD: 1.83 ± 0.92 vs 2.90 ± 1.40, p < 0.01). The analysis of covariance with possible confounding factors as covariates also showed that Z‐scores were significantly lower in the early‐onset group than in the late‐onset group (p < 0.01). The proportion of patients with atrophy was significantly lower in the early‐onset group than in the late‐onset group (44% vs 71%, p < 0.05).

Conclusions

The present study using the VSRAD suggests that early‐onset AD shows less atrophy in the entorhinal cortex than late‐onset AD. Copyright © 2012 John Wiley & Sons, Ltd.
ZERO‐INFLATED ENDOGENOUS COUNT IN CENSORED MODEL: EFFECTS OF INFORMAL FAMILY CARE ON FORMAL HEALTH CARE
Authors: Lee Myoung‐jae , Kim Young‐sook
Published: May 2012

If informal family health care is a substitute for formal health care, then there is a scope to reduce formal health care cost by promoting informal family health care. With the use of Korean data for the elderly, this paper estimates the effects of informal family health care on formal health care, where the former is measured by the number of caregivers and the latter is measured by the formal health care expenditure. This task, however, poses a number of difficulties. The first is that the number of the family caregivers is an endogenous count regressor. The second is that there are too many zeros in the count (85%). The third is that the response variable also has a nontrivial proportion of zeros (14%). This paper overcomes these problems by combining ‘control function approach’, ‘zero‐inflated’ counts, and a semiparametric estimator for censored models. The resulting procedure avoids strong parametric assumptions and behaves well computationally. Our main empirical finding is that informal family health care has a large substitute effect for diabetics and that there are also weak evidences that informal family health care has substitute effects for high blood pressure and mental diseases. Copyright © 2012 John Wiley & Sons, Ltd.
Assessment of current water pollution loads in Europe: estimation of gridded loads for use in global water quality models
Authors: Williams Richard , Keller Virginie , Voß Anja , Bärlund Ilona , Malve Olli , Riihimäki Juha , Tattari Sirkka , Alcamo Joseph
Published: May 2012

A methodology for estimating the loading of pollutants to water courses across all of pan‐Europe, an area reaching to the River Don in the east and including some Mediterranean rim countries in the near east and North Africa is presented. Loadings come from point (domestic effluent, manufacturing discharge and urban runoff) and diffuse (scattered settlements and land use) sources. The loads have been calculated on a countrywide basis using readily available data held by national and international bodies. These loads are downscaled to the grid cells (5 × 5′) used in the model. The paper illustrates the general framework for making these calculations using biochemical oxygen demand (BOD) and total dissolved solids (TDS), and estimated loads for periods representing 1990, 1995, 2000 and 2005 are presented as maps.

According to the model, in 2005, annual BOD loads came mostly from domestic effluent (3 Mt) and diffuse sources (5 Mt, mainly attributed to livestock). Manufacturing, urban runoff and scattered settlements contributed annual loads of 0.33, 0.15 and 1.2 Mt, respectively. For TDS, annual manufacturing loads were 65 Mt and annual domestic loads 28 Mt. Diffuse loadings (36 Mt) came from irrigated land and therefore showed a different spatial pattern from BOD. The total annual diffuse load of TDS was 56 Mt. Scattered settlements contributed only 9.6 Mt to the total pan‐European load. Some limited comparison of the loads estimated in this study for BOD with those estimated by others for countries and large catchments in the area has been carried out. Copyright © 2012 John Wiley & Sons, Ltd.
CONSTRUCTION CHARACTERISTICS AND MANAGEMENT PRACTICES OF IN‐FARM IRRIGATION PONDS IN INTENSIVE AGRICULTURAL SYSTEMS — AGRONOMIC AND ENVIRONMENTAL IMPLICATIONS
Authors: Juan Melchor , Casas Jesús , Bonachela Santiago , Fuentes‐Rodríguez Francisca , Gallego Irene , Elorrieta María Antonia
Published: May 2012

The structural and management characterization of 101 ponds, used for greenhouse drip irrigation, was assessed on the south‐eastern coast of Spain, with the objective of proposing more sustainable management practices. Different management methods were carried out by growers with the aim of controlling pond biological activity and improving the irrigation water quality. Pond covering was highly effective in preventing submerged aquatic vegetation (SAV) development but the high cost of installing and maintaining covers limit its use. Pond dredging and biocide treatments were relatively expensive and ineffective in controlling mid and long‐term SAV development. No clear criteria were observed for biocide use (products, dosage and scheduling). SAV developed spontaneously in 48.5% of uncovered ponds. Chara species, which tend to form dense meadows in the pond bottom and are highly valuable for aquatic biodiversity conservation, may improve the water quality and are unlikely to hinder agricultural pond uses. More sustainable management practices based on preserving SAV in ponds, particularly charophytes, and reducing or suppressing dredging and biocide use may be successful in accomplishing both agronomic and environmental pond functions. Copyright © 2012 John Wiley & Sons, Ltd.
Clinical course of non‐specific low back pain: A systematic review of prospective cohort studies set in primary care
Authors: Itz C.J. , Geurts J.W. , van Kleef M. , Nelemans P.
Published: May 2012

Background and objective

Non‐specific low back pain is a relatively common and recurrent condition for which at present there is no effective cure. In current guidelines, the prognosis of acute non‐specific back pain is assumed to be favourable, but this assumption is mainly based on return to function. This systematic review investigates the clinical course of pain in patients with non‐specific acute low back pain who seek treatment in primary care.

Databases and data treatment

Included were prospective studies, with follow‐up of at least 12 months, that studied the prognosis of patients with low back pain for less than 3 months of duration in primary care settings. Proportions of patients still reporting pain during follow‐up were pooled using a random‐effects model. Subgroup analyses were used to identify sources of variation between the results of individual studies.

Results

A total of 11 studies were eligible for evaluation. In the first 3 months, recovery is observed in 33% of patients, but 1 year after onset, 65% still report pain. Subgroup analysis reveals that the pooled proportion of patients still reporting pain after 1 year was 71% at 12 months for studies that considered total absence of pain as a criterion for recovery versus 57% for studies that used a less stringent definition. The pooled proportion for Australian studies was 41% versus 69% for European or US studies.

Conclusions

The findings of this review indicate that the assumption that spontaneous recovery occurs in a large majority of patients is not justified. There should be more focus on intensive follow‐up of patients who have not recovered within the first 3 months.
Polyurethane modified with an antithrombin‐heparin complex via polyethylene oxide linker/spacers: Influence of PEO molecular weight and PEO‐ATH bond on catalytic and direct anticoagulant functions
Authors: Sask Kyla N. , Berry Leslie R. , Chan Anthony K. C. , Brash John L.
Published: May 2012

A segmented polyurethane (PU) was modified with polyethylene oxides (PEO) of varying molecular weight and end group. The PEO served as linker/spacers to immobilize an antithrombin‐heparin (ATH) anticoagulant complex on the PU. Isocyanate groups were introduced into the PU to enable attachment of either “conventional” homo‐bifunctional dihydroxy‐PEO (PEO‐OH surface) or a hetero‐bifunctional amino‐carboxy‐PEO (PEO‐COOH surface). The PEO surfaces were functionalized with N‐hydroxysuccinimide (NHS) groups using appropriate chemistries, and ATH was attached to the distal NHS end of the PEO (PEO‐OH‐ATH and PEO‐COOH‐ATH surfaces). Water contact angle and fibrinogen adsorption measurements showed increased hydrophilicity and reduced fibrinogen adsorption from buffer on all PEO surfaces compared to unmodified PU. ATH uptake on NHS‐functionalized PEO was quantified by radiolabeling. Despite the different PEO molecular weights and end groups, and NHS‐functionalization chemistries, the surface densities of ATH were similar. The adsorption of fibrinogen and antithrombin (AT) from plasma was measured in a single experiment using dual radiolabeling. On PEO‐ATH surfaces fibrinogen adsorption was minimal while AT adsorption was high showing the selectivity of the heparin moiety of ATH for AT. The PEO‐COOH‐ATH surfaces showed slightly greater AT adsorption than the PEO‐OH‐ATH surfaces. Thrombin adsorption on all of the PEO‐ATH surfaces was greater than on the corresponding PEO surfaces without ATH, and was highest on the PEO‐OH‐ATH, suggesting potential anticoagulant properties for this surface via direct thrombin inhibition by the AT portion of ATH. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:2821–2828, 2012.
Comment on the paper “Extensive Theoretical Studies of a New Energetic Material: Tetrazino‐Tetrazine‐Tetraoxide (TTTO)” by Xinli Song, Jicun Li, Hua Hou, and Baoshan Wang
Authors: Jorgensen Kameron R. , Wilson Angela K.
Published: May 2012

Discrepancies are noted in the implementation and presentation of the ccCA methodology in a previous publication, “Extensive Theoretical Studies of a New Energetic Material: Tetrazino‐tetrazine‐tetraoxide (TTTO)” by Xinli Song, Jicun Li, Hua Hou, and Baoshan Wang. The enthalpy of formation for TTTO has been re‐evaluated using the correct implementation of the ccCA methodology, demonstrating the results to be comparable to those of other ab initio composite methods. © 2012 Wiley Periodicals, Inc.
Comparative DFT study of N2 and no adsorption on vanadium clusters Vn (n = 2–13)
Authors: Wu Guangfen , Yang Mingli , Guo Xingyu , Wang Jinlan
Published: May 2012

Using gradient‐corrected density functional theory, we have comparatively studied the adsorption properties of diatomic molecules N2 and NO on vanadium clusters up to 13 atoms. Spontaneous dissociation is found for N2 adsorbing on Vn with n = 4–6, 12, and for NO with n = 3–12, respectively, whereas for the rest of the clusters, N2 (NO) molecularly adsorbs on the cluster for all the possible sites. The incoming N2 retains the magnetism of Vn except for V2 and V6 whose moments are quenched from 2 μB to zero. Consequently, the moments of VnN2 (n = 2–13) show even/odd oscillation between 0 and 1 μB. On the adsorption of NO, the magnetic moments of Vn with closed electronic shell are raised to 1 μB at n = 4, 8, and 10, and 3 μB at n = 12, whereas for open shell clusters, their magnetic moments increase for n = 5 and 9 and decrease for n = 2, 3, 5–7, 11, and 13 by 1 μB. These findings are rationalized by combinatory analysis from several aspects, for example, the geometry and stability of bare clusters, charge transfer induced by the adsorption, feature of frontier orbitals, and spin density distribution. © 2012 Wiley Periodicals, Inc.
Coral: QSPR modeling of rate constants of reactions between organic aromatic pollutants and hydroxyl radical
Authors: Toropov A. A. , Toropova A. P. , Rasulev B. F. , Benfenati E. , Gini G. , Leszczynska D. , Leszczynski J.
Published: May 2012

The rate constants (KOH) of reactions between 78 organic aromatic pollutants and hydroxyl radical were examined. Simplified molecular input line entry system was used as representation of the molecular structure of the pollutants. Quantitative structure–property relationships was developed using CORAL software (http://www.insilico.eu/CORAL) for four random splits of the data into the subtraining, calibration, and test sets. The obtained results reveal good predictive potential of the applied approach: correlation coefficients (r2) for the test sets of the four random splits are 0.75, 0.91, 0.84, and 0.80. Using the Monte Carlo method CORAL software generated the optimal descriptors for one‐variable models. The reproducibility of each model was tested performing three runs of the Monte Carlo optimization. The current data were compared to previous results and discussed. © 2012 Wiley Periodicals, Inc.
Gas‐phase reactions of SiHn+ (n = 1,2) with NF3: A computational investigation on the detailed mechanistic aspects
Authors: Antoniotti Paola , Bottizzo Elena , Borocci Stefano , Giordani Maria , Grandinetti Felice
Published: May 2012

The mechanism of the gas‐phase reactions of SiHn+ (n = 1,2) with NF3 were investigated by ab initio calculations at the MP2 and CAS‐MCSCF level of theory. In the reaction of SiH+, the kinetically relevant intermediates are the two isomeric forms of fluorine‐coordinated intermediate HSi‐F‐NF2+. These species arise from the exoergic attack of SiH+ to one of the F atoms of NF3 and undergo two competitive processes, namely an isomerization and subsequent dissociation into SiF+ + HNF2, and a singlet‐triplet crossing so to form the spin‐forbidden products HSiF+ + NF2. The reaction of SiH2+ with NF3 involves instead the concomitant formation of the nitrogen‐coordinated complex H2Si‐NF3+ and of the fluorine‐coordinated complex H2Si‐F‐NF2+. The latter isomer directly dissociates into NF2+ + H2SiF, whereas the former species preferably undergoes the passage through a conical intersection point so to form a H2SiF‐NF2+ isomer, which eventually dissociates into H2SiF+ and NF2. © 2012 Wiley Periodicals, Inc.
Balancing target flexibility and target denaturation in computational fragment‐based inhibitor discovery
Authors: Foster Theresa J. , MacKerell Alexander D. , Guvench Olgun
Published: May 2012

Accounting for target flexibility and selecting “hot spots” most likely to be able to bind an inhibitor continue to be challenges in the field of structure‐based drug design, especially in the case of protein–protein interactions. Computational fragment‐based approaches using molecular dynamics (MD) simulations are a promising emerging technology having the potential to address both of these challenges. However, the optimal MD conditions permitting sufficient target flexibility while also avoiding fragment‐induced target denaturation remain ambiguous. Using one such technology (Site Identification by Ligand Competitive Saturation, SILCS), conditions were identified to either prevent denaturation or identify and exclude trajectories in which subtle but important denaturation was occurring. The target system used was the well‐characterized protein cytokine IL‐2, which is involved in a protein–protein interface and, in its unliganded crystallographic form, lacks surface pockets that can serve as small‐molecule binding sites. Nonetheless, small‐molecule inhibitors have previously been discovered that bind to two “cryptic” binding sites that emerge only in the presence of ligand binding, highlighting the important role of IL‐2 flexibility. Using the above conditions, SILCS with hydrophobic fragments was able to identify both sites based on favorable fragment binding while avoiding IL‐2 denaturation. An important additional finding was that acetonitrile, a water‐miscible fragment, fails to identify either site yet can induce target denaturation, highlighting the importance of fragment choice. © 2012 Wiley Periodicals, Inc.
Enhancement of microbial reductive dechlorination of polychlorinated biphenyls (PCBs) in a marine sediment by nanoscale zerovalent iron (NZVI) particles
Authors: Zanaroli Giulio , Negroni Andrea , Vignola Marta , Nuzzo Andrea , Shu Hung‐Yee , Fava Fabio
Published: May 2012

BACKGROUND: Microbial reductive dechlorination of polychlorinated biphenyls (PCBs) in contaminated sediments is characterized by long lag periods and low rates. Zerovalent iron is a source of cathodic hydrogen that has been proposed as an easily amendable agent to stimulate PCB microbial dechlorination. The objective of this study was to evaluate the effect of nanoscale zerovalent iron (NZVI) particles on the reductive dechlorination of Aroclor 1254 PCBs and on the indigenous microbial community in a marine sediment under in situ‐like biogeochemical conditions.

RESULTS: A 30‐weeks lag phase followed by a modest dechlorination (5.0 ± 0.4 mol%) of hepta‐ through penta‐chlorinated PCBs occurred in NZVI‐free cultures during 36 weeks of incubation. NZVI (6.7 g kg−1) reduced the lag phase of PCB dechlorination by 10 weeks, leading to a four‐fold increase of the dechlorination extent at the end of the incubation. NVZI exerted some toxic effect on sulphate reducing bacteria, which were transiently inhibited until its complete oxidation occurred, and favoured the enrichment of a phylotype closely related to the PCB dehalorespiring bacterium Dehalobium chlorocoercia DF‐1, probably via the simultaneous partial inhibition of sulphate reducing bacteria and the release of molecular hydrogen. Finally, DGGE analysis showed that NZVI did not affect markedly the biodiversity of the indigenous microbial community.

CONCLUSION: NZVI displayed a very high biostimulation effect on PCB microbial dechlorination and a very low impact on the sediment indigenous microbial community. Supplementation with NZVI particles might thus be a sustainable effective strategy to intensify PCB reductive dechlorination processes in marine sediments. Copyright © 2012 Society of Chemical Industry
Study of the conditions for multi‐modal chromatographic capture of Fab′ from dual‐salt precipitated E. coli homogenate
Authors: Balasundaram Bangaru , Chhatre Sunil , Arora Dhruv , Titchener‐Hooker Nigel J , Bracewell Daniel G
Published: May 2012

BACKGROUND: In the commercial‐scale purification of immunotherapeutics, Protein A chromatography is employed routinely for its high binding capacity and selectivity. Nevertheless, matrix cost and ligand leaching issues remain and there are many alternatives such as ion‐exchange and multi‐modal resins that are less expensive. However, binding capacities are lower than Protein A owing to the co‐adsorption of protein impurities. One solution involves removing impurities before chromatography by precipitation and a potential approach presented in the literature recently employs a dual‐salt precipitation technique. The current study explores the impact of this upon the capture of an antibody fragment by a multimodal cation exchange resin.

RESULTS: The dual salt precipitation procedure employed here removed 36% of the contaminant proteins. A microscale chromatography pipette tip approach was used in a high throughput screening format to scout rapidly for favourable binding conditions successfully. Higher binding capacities were achieved by activating the hydrophobic binding modality of the resin at feed ionic strengths of around 150 mS cm−1 using ammonium sulphate. This was better than using the ion‐exchange modality at below 10 mS cm−1.

CONCLUSIONS: Dual salt precipitation followed by chromatographic capture using this resin were found to be complementary to one another since the removal of protein impurities by dual salt precipitation resulted in a two‐fold improvement in terms of binding capacity. © 2012 Society of Chemical Industry
Supercritical and enzymatic technologies for the production of lysophosphatidylcholine
Authors: Casado Víctor , Señorans Francisco.J , Reglero Guillermo , Torres Carlos F.
Published: May 2012

BACKGROUND

This study focuses on obtaining a highly purified lysophosphatidylcholine from phosphatidylcholine powder via hydrolysis, catalyzed by a phospholipase A2 in a solvent‐free medium, and subsequent purification either by organic solvent or by supercritical fluid extraction.

RESULTS

A solvent‐free hydrolysis reaction of phosphatidylcholine powder to produce lysophosphatidylcholine with residual phosphatidylcholine content lower than 10% has been described and scaled‐up. Supercritical fluid mixtures of carbon dioxide, ethanol and formic acid were studied at 250, bar 50 °C to selectively extract the free fatty acids fraction from hydrolyzed phosphatidylcholine. Finally, a solid product with lysophosphatidylcholine content of c. 95% (w/w) and with free fatty acids content of c. 5% (w/w) was attained. Under optimum conditions, the content of the original phosphatidylcholine in the lysophosphatidylcholine product was lower than 5% (w/w).

CONCLUSIONS

An efficient hydrolysis of phosphatidylcholine by phospholipase A2 in a solvent‐free reaction was developed. In addition, three novel strategies for the purification of lysophosphatidylcholine have been developed: (1) hexane/formic acid extraction process, (2) supercritical CO2 extraction with ethanol as modifier, and (3) supercritical CO2 extraction with ethanol/formic acid as modifier. Copyright © 2012 Society of Chemical Industry
Differentiation of fresh and frozen/thawed fish, European sea bass (Dicentrarchus labrax), gilthead seabream (Sparus aurata), cod (Gadus morhua) and salmon (Salmo salar), using volatile compounds by SPME/GC/MS
Authors: Leduc François , Krzewinski Frédéric , Le Fur Bruno , N'Guessan Assi , Malle Pierre , Kol Ossarath , Duflos Guillaume
Published: May 2012

BACKGROUND: A simple method based on solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) was applied for studying the volatile profiles of whole fish samples of European sea bass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) and fillets of cod (Gadus morhua) and salmon (Salmo salar) during frozen storage in order to be able to differentiate a fresh product from one that has been frozen. Analysis of volatile compounds was performed on these two product types, fresh and after freezing/thawing following storage at − 20 °C for 30 and 90 days.

RESULTS: More than a hundred volatile compounds were found by SPME/GC/MS. Statistical processing by principal component analysis and ascending hierarchical classification was used to classify the samples into categories and verify the possibility of separating fresh samples from those that had been frozen and thawed. The compounds to be used as differentiators were identified. Four compounds were common to all species: dimethyl sulfide, 3‐methylbutanal, ethyl acetate and 2‐methylbutanal. Not only were they found in larger quantities after thawing but they also increased with the duration of storage at − 20 °C.

CONCLUSION: These four compounds can therefore be considered as potential markers of differentiation between a fresh product and one that has been frozen. Copyright © 2012 Society of Chemical Industry
Identification of functions linking quorum sensing with biofilm formation in Burkholderia cenocepacia H111
Authors: Inhülsen Silja , Aguilar Claudio , Schmid Nadine , Suppiger Angela , Riedel Kathrin , Eberl Leo
Published: May 2012

Burkholderia cenocepacia has emerged as an important pathogen for patients suffering from cystic fibrosis (CF). Previous work has shown that this organism employs the CepIR quorum‐sensing (QS) system to control the expression of virulence factors as well as the formation of biofilms. To date, however, very little is known about the QS‐regulated virulence factors and virtually nothing about the factors that link QS and biofilm formation. Here, we have employed a combined transcriptomic and proteomic approach to precisely define the QS regulon in our model strain B. cenocepacia H111, a CF isolate. Among the identified CepR‐activated loci, three were analyzed in better detail for their roles in biofilm development: (i) a gene cluster coding for the BclACB lectins, (ii) the large surface protein BapA, and (iii) a type I pilus. The analysis of defined mutants revealed that BapA plays a major role in biofilm formation on abiotic surfaces while inactivation of the type I pilus showed little effect both in a static microtitre dish‐based biofilm assay and in flow‐through cells. Inactivation of the bclACB lectin genes resulted in biofilms containing hollow microcolonies, suggesting that the lectins are important for biofilm structural development.
Prokaryotic community structure and respiration during long‐term incubations
Authors: Baltar Federico , Lindh Markus V. , Parparov Arkadi , Berman Tom , Pinhassi Jarone
Published: May 2012

Despite the importance of incubation assays for studies in microbial ecology that frequently require long confinement times, few reports are available in which changes in the assemblage structure of aquatic prokaryotes were monitored during long‐term incubations. We measured rates of dissolved organic carbon degradation and microbial respiration by consumption of dissolved oxygen (DO) in four experiments with Lake Kinneret near‐surface water and, concomitantly, we analyzed the variability in prokaryotic community structure during long‐term dark bottle incubations. During the first 24 h, there were only minor changes in bacterial community composition. Thereafter there were marked changes in the prokaryotic community structure during the incubations. In contrast, oxygen consumption rates (a proxy for both respiration and dissolved organic carbon degradation rates) remained stable for up to 10–23 days. This study is one of the first to examine closely the phylo‐genetic changes that occur in the microbial community of untreated freshwater during long‐term (days) incubations in dark, sealed containers. Novel information on the diversity of the main bacterial phylotypes that may be involved in dissolved organic matter degradation in lake Kinneret is also provided. Our results suggest that, under certain ecological settings, constant community metabolic rates can be maintained as a result of shifts in community composition.
Outpatient treatment in German adolescents with depression: an analysis of nationwide health insurance data
Authors: Hoffmann Falk , Glaeske Gerd , Petermann Franz , Bachmann Christian J.
Published: May 2012

Purpose

Data on medical treatment of adolescents with depression are scarce. This study aimed to examine outpatient health services utilisation of depressive disorders in adolescents.

Methods

Data of a statutory health insurance company were analysed and outpatients from 12 to 18 years old with diagnosed depression during a 1‐year period (2009) were identified. For this cohort, the prescription of antidepressants and psychotherapy was evaluated with respect to age and sex.

Results

A total of 4295 patients (41.2% males; mean age, 15.5 years) matched the inclusion criteria. Of the patients, 29.7% consulted a child and adolescent psychiatrist. A total of 59.6% were treated with psychotherapy only, 9.6% were treated with a combination of psychotherapy and antidepressants, and 1.9% received only antidepressants. For 28.8% of patients, no specific depression‐related treatment was prescribed. A total of 1357 packages of antidepressants were analysed, of which fluoxetine (24.4% of prescriptions), citalopram (14.0%), and mirtazapine (9.7%) were the most frequently prescribed substances. Regarding substance classes, selective serotonin reuptake inhibitors (SSRIs; 55.6%), tricyclic antidepressants (TCAs; 17.9%), and hypericum (St. John's wort; 8.5%) were most common.

Conclusions

Although the underlying data were coded for insurance purposes, which might result in some data impreciseness, this naturalistic study furnishes evidence that outpatient treatment of adolescents with depressive disorders in Germany only partly complies with guideline recommendations for first‐line treatment: Although the prescriptions of SSRI for adolescent depression have risen over recent years, still, a quarter of antidepressant prescriptions for adolescents with depression were TCA or hypericum. Therefore, dissemination of knowledge on state‐of‐the‐art treatment for adolescent depression remains a major educational goal. Copyright © 2012 John Wiley & Sons, Ltd.
In situ synthesis of polybutene‐1/polypropylene spherical alloys within a reactor with an MgCl2‐supported Ziegler–Natta catalyst
Authors: He Aihua , Zheng Weiping , Shi Yangwei , Liu Guoqing , Yao Wei , Huang Baochen
Published: May 2012

A series of isotactic polybutene‐1/polypropylene (PB/PP) alloys with spherical morphology were prepared by MgCl2‐supported Ziegler‐Natta catalyst with sequential two‐stage polymerization technology. The first formed PP particles were used as micro‐reactors to initiate the bulk precipitation polymerization of butene‐1 further. The porous PP particles as a hard framework may prevent the adhesion of PB particles during the bulk precipitation polymerization process. At the same time, the bulk precipitation polymerization process allows for maximization of the butene‐1 polymerization rate and simplifies the butene‐1 polymerization process considerably. Finally, spherical PB alloys with a super‐high molecular weight PB component and adjustable PP component were synthesized in situ within the reactor. The structures and properties of the PB/PP alloys were characterized by gel permeation chromatography, 13C nuclear magnetic resonance, Fourier transform IR, scanning electron microscopy, differential scanning calorimetry and X‐ray diffraction. The results showed that the MgCl2‐supported Ziegler‐Natta catalyst showed relatively high stereospecificity and efficiency for both propylene and butene‐1 polymerization. The incorporation of propylene on the PB matrix affects the properties of the final products markedly. The PB/PP alloys are expected to have a broader range of applications as a new family of high performance materials. Copyright © 2012 Society of Chemical Industry
Influence of media polarity on the rate of activation of “dormant” chains in nitroxide‐mediated radical polymerization
Authors: Zaremski Mikhail , Borisova Olga , Xin Chen , Golubev Vladimir B. , Billon Laurent
Published: May 2012

Rate constants of decomposition of “living” polymeric adducts polystyrene (PS)‐TEMPO, poly‐4‐vinylpyridine‐TEMPO, PS‐SG1, and polyacrylic acid‐SG1 in different solvents were determined by the method of a competitive inhibition by means of electron spin resonance. It was found that with the increase in polarity of solvent, the values of constants become higher for all systems studied. This effect opens a new way of activating chains in nitroxide‐mediated radical polymerization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Controlled polymerization of methyl acrylate for high‐molecular‐weight polymers by pentafluorophenylbis(triflyl)methane‐promoted group transfer polymerization using triisopropylsilyl ketene acetal
Authors: Takada Kenji , Fuchise Keita , Chen Yougen , Satoh Toshifumi , Kakuchi Toyoji
Published: May 2012

The group transfer polymerization (GTP) of methyl acrylate (MA) was studied using pentafluorophenylbis(triflyl)methane (C6F5CHTf2) as the organocatalyst and 1‐trimethylsiloxy‐, 1‐triethylsiloxy‐, and 1‐triisopropylsiloxy‐1‐methoxy‐2‐methyl‐1‐propene (MTSMe, MTSEt, and MTSiPr, respectively) as the initiators. The C6F5CHTf2‐promoted GTP of MA using MTSiPr proceeded in a living nature to produce poly(methyl acrylate)s (PMAs) with controlled molecular weights and narrow molecular weight distributions, which allowed the synthesis of high‐molecular‐weight PMA with the number‐average molecular weight (Mn(SEC)) of up to 108,000 and the polydispersity (Mw/Mn) of 1.07. The matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry measurement revealed that the obtained PMA possessed the chain end structure that originated from MTSiPr, showing that the C6F5CHTf2‐promoted GTP of MA proceeded without any side reactions. In addition, the kinetic study and the postpolymerization experiment supported the living manner of the polymerization. Moreover, the block copolymerization of MA and n‐butyl acrylate (nBA) smoothly proceeded to afford the well‐defined PMA‐block‐poly(n‐butyl acrylate) (PnBA). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Preparation of chiral amino acid materials and the study of their interactions with 1,1‐Bi‐2‐naphthol
Authors: Moore Beth L. , O'Reilly Rachel K.
Published: May 2012

The amino acid tryptophan has been converted into acrylamide monomers using L/D‐tryptophan methyl ester forming the enantiopure chiral monomers. Attempts were made to polymerize these monomers via reversible addition fragmentation chain transfer (RAFT) polymerization to form poly(tryptophan). Unfortunately, this proved difficult, and instead, a postpolymerization modification route was used by first synthesizing poly(pentafluorophenyl acrylate) via RAFT, which was then substituted with L‐tryptophan methyl ester to give poly(L‐tryptophan). The interactions of the newly synthesized tryptophan monomers, as well as previously reported phenylalanine monomers, were studied in the presence of rac‐BINOL. It has been shown that the enantiomers of tryptophan have a stronger interaction with BINOL than phenylalanine and this has been attributed to the larger π system on the side chain. By monitoring the shifts and splitting of the phenolic protons of BINOL, it has been observed that S‐BINOL interacts more favorably with L‐monomer enantiomers and R‐BINOL with D‐monomer enantiomers. Similar interactions have also been seen with poly(phenylalanine) and the newly synthesized poly(tryptophan) materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012