bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refining the glycerin phase from palm‐oil biodiesel by ion‐exchange with cationic resins
Authors: Gallego Morales Luis Javier , Cardeño López Fernando , Alberto Rios Luis 
Published: February 2013

AbstractBackgroundGlycerin is produced as an 11% by‐product in biodiesel manufacturing. Impurities are concentrated in the glycerin phase. High‐vacuum distillation of glycerin is an energy‐intensive process. A new low‐cost purification strategy for glycerin is needed. This paper reports the refining of the glycerin phase obtained from palm‐oil biodiesel synthesis by ion‐exchange with cationic resins. In the literature and to the best of the authors' knowledge, the use of a real glycerin phase from biodiesel has not been reported. The ion‐exchange equilibrium was determined in a batch process, while variables for the industrial scaling‐up were studied in continuous operation.ResultsThe sodium content obtained with low amounts of resin is lower than that obtained with mineral‐acid refining. Almost complete sodium removal could be achieved in continuous operation. Langmuir and Freundlich models give a good fit to the equilibrium data. Amberlyst was the best resin. Breakthrough capacity was 96% of static exchange capacity. 95% of the static ion exchange was recovered by washing with water‐soap.ConclusionA 96.6% purification level of glycerol was obtained with the resin Amberlyst 15, using a methanol content of 60%, liquid phase flow of 0.8 mL min−1 and 0.3 g resin g−1 glycerin phase; dynamic exchange capacity was 96% of the static exchange capacity. Exchange capacity is almost completely regenerated by washing with water‐soap. © 2013 Society of Chemical Industry
Extractive recovery of aqueous diamines for bio‐based plastics production
Authors: Krzyżaniak Agnieszka , Schuur Boelo , de Haan André B. 
Published: February 2013

AbstractBackgroundThis paper reports an extractant screening study for the recovery of putrescine (butylene‐1,4‐diamine,BDA) and cadaverine (pentylene‐1,5‐diamine,PDA) from aqueous solutions (e.g. fermentation broths) by liquid–liquid extraction. Several extractants were studied, including 4‐nonylphenol, 3,4‐bis((2‐ethylhexyl)oxy)phenol, di‐2‐ethylhexyl phosphoric acid (D2EHPA), Versatic acid 1019, di‐nonyl‐naphthalene‐sulfonic acid (DNNSA), and 4‐octylbenzaldehyde. 1‐Octanol, 2‐octyl‐1‐dodecanol and heptane were used as diluents, and temperatures of 25 °C and 65 °C.ResultsThe most promising solvent is 4‐nonylphenol, hardly leaching into the aqueous raffinate (19 ppm), and showingBDAdistribution coefficients very strongly dependent on the extractant concentration, ranging from very low distribution ( D ∼ 1 at <20 wt% 4‐nonylphenol in 1‐octanol at 25 °C) to high distribution (D > 100) for pure 4‐nonylphenol at 25 °C. The strong dependency of the distribution on extract phase composition was applied to efficiently back‐extract up to 90%BDAin a single step. To achieve this, the pure 4‐nonylphenol used in extraction was diluted to a 20 wt% dilution in 1‐octanol. The use of 4‐nonylphenol as extractant was also examined forPDA, and higher distributions were observed than forBDA, which can be attributed to the longer hydrocarbon chain ofPDA.ConclusionsRecovery of diamines from aqueous medium can be accomplished in an effective way using 4‐nonylphenol as extractant. These results may be used to develop a bio‐based butylene‐1,4‐diamine production route. © 2013 Society of Chemical Industry
Calibration and validation of a model describing complete autotrophic nitrogen removal in a granular SBR system
Authors: Vangsgaard Anna Katrine , Mutlu A. Gizem , Gernaey Krist V. , Smets Barth F. , Sin Gürkan 
Published: February 2013

AbstractBACKGROUNDA validated model describing the nitritation‐anammox process in a granular sequencing batch reactor (SBR) system is an important tool for: (a) design of future experiments; and (b) prediction of process performance during optimization, while applying process control, or during system scale‐up.RESULTSA model was calibrated using a step‐wise procedure customized for the specific needs of the system. The important steps in the procedure were initialization, steady‐state and dynamic calibration, and validation. A fast and effective initialization approach was developed to approximate pseudo steady‐state in the biofilm system. For oxygen mass transfer coefficient (kLa) estimation, long‐term data, removal efficiencies, and the stoichiometry of the reactions were used. For the dynamic calibration a pragmatic model fitting approach was used – in this case an iterative Monte Carlo based screening of the parameter space – to find the best fit of the model to dynamic data. Finally, the calibrated model was validated with an independent data set.CONCLUSIONThe calibration procedure presented is the first customized procedure for this type of system and is expected to contribute to achieving a fast and effective model calibration, an important enabling tool for various biochemical engineering design, control and operation problems. © 2013 Society of Chemical Industry
Exocytosis of neurosecretory granules from the crustacean sinus gland in freeze‐fracture
Authors: Shivers Richard R. 
Published: February 2013

AbstractExocytosis is clearly shown in freeze‐fracture preparations to be the mechanism for neurosecretion granule release from axon endings in the crayfish sinus gland. The cytoplasmic leaflet (A‐face) of axon ending membrane is characterized by randomly situated depressions representing invaginations of the axolemma, which are in contact with limiting membranes of neurohormone granules in the subjacent cytoplasm. The extracellular leaflet (B‐face) of the axolemma at release sites exhibits complementary volcano‐shaped protrusions which are cross‐fractures through necks of channels formed by invaginating plasma membrane in contact with underlying neurosecretion granules. Structural variation in B‐face protrusions is consistent with a spectrum of exocytotic profiles in various stages of formation, and with granules at different stages of passage out of the endings. Evidence in this study suggests that formation of exocytotic structures may begin by alteration of axon membrane structure at the neurosecretory ending‐hemolymph interface prior to contact of the neurohormone granules with the axolemma. Limiting membranes of neurosecretory granules exhibit protrusions which appear to interconnect granules adjacent to release sites and to attach granules to the axolemma. Freeze‐fracture is clearly shown to be an invaluable tool for monitoring the degree of exocytosis exhibited by sinus glands under normal conditions and under experimental acceleration of hormone release. This technique is capable therefore, of detecting slight increases in numbers of exocytotic profiles much more quickly and accurately than the examination of random thin sections.
Frequent detection of cytomegalovirus (CMV) DNA in the lower respiratory tract in CMV‐seropositive pediatric patients with underlying chronic bronchopulmonary diseases lacking canonical immunosuppression
Authors: Escribano Amparo , Chilet Marifina , Clari María Ángeles , Lucas Raquel , Costa Elisa , Bravo Dayana , Muñoz‐Cobo Beatriz , Borrás Rafael , Navarro David 
Published: February 2013

AbstractCytomegalovirus (CMV) may be a relevant cause of morbidity in patients displaying various inflammatory diseases. In this study, it was investigated whether CMV DNA is detected in the lower respiratory tract and the systemic compartment in pediatric patients with chronic or recurrent bronchopulmonary diseases. A total of 42 lower respiratory tract specimens and 11 paired plasma samples from 42 patients were analyzed for the presence of CMV DNA by real‐time PCR. The respiratory specimens were also screened for the presence of respiratory viruses and human herpesvirus 6 (HHV‐6) and 7 (HHV‐7) by PCR methods. Quantitative bacterial and fungal cultures were performed. IL‐6 levels in the respiratory specimens were quantified using ELISA. CMV DNA was detected either in the lower respiratory airways, in plasma, or both in 54.5% of CMV‐seropositive patients. The levels of IL‐6 were significantly higher in these patients than in those with no detectable levels of CMV DNA. HHV‐6 and HHV‐7 DNA were detected in three and one patients, respectively. Respiratory viruses were detected in 13 of the 42 patients. Significant growth of one or more bacterial species was observed in 17 patients. No significant association was found between the presence of CMV DNA and the detection of other microorganisms. The data indicated that the presence of CMV DNA in the lower respiratory tract is a frequent finding in children with chronic or recurrent bronchopulmonary diseases. Further, prospective observational studies are needed to assess the impact of this phenomenon, if any, on the clinical course of these patients. J. Med. Virol. 85:888–892, 2013. © 2013 Wiley Periodicals, Inc.
High frequency of complex mutational patterns in lamivudine resistant hepatitis B virus isolates
Authors: Neumann‐Fraune Maria , Beggel Bastian , Pfister Herbert , Kaiser Rolf , Verheyen Jens 
Published: February 2013

AbstractThe evolution of hepatitis‐B virus (HBV) drug resistance is characterized by the emergence of resistance conferring mutations and compensatory mutations. Therefore HBV drug‐resistant isolates often harbor multiple mutations in the reverse transcriptase (RT) and corresponding mutations in the hepatitis B surface antigen (HBsAg). In this study mutational patterns of 60 HBV isolates harboring drug resistance mutations rtM204V or rtM204I were retrospectively analyzed. Both mutations, especially mutation rtM204V, were most often accompanied by compensatory mutations rtV173L and rtL180M but also by mutations conferring entecavir (n = 5) or adefovir resistance (n = 4). In addition, 22 (36.7%) drug resistant HBV isolates carried mutations related to immune escape in the HBsAg. In seven cases premature stop codons in HBsAg were detected resulting in the expression of truncated HBsAg. Clonal analysis of these seven quasispecies even disclosed the presence of HBV isolates carrying further stop codons and in one case the occurrence of resistance mutation rtA181T without the stop codon mutation sW172*. Interestingly, only one HBV clone carried the resistance mutations rtM204V and rtA181T. HBV drug resistant isolates frequently harbored HBsAg mutations associated with immune escape or disease progression pointing to a complex interaction of both proteins. HBV genotypic resistance tests based on population sequencing methods seemed to be inappropriate for determining the clinical relevance of stop codons in the HBsAg. J. Med. Virol. 85:775–779, 2013. © 2013 Wiley Periodicals, Inc.
HTR2A−1438A/G polymorphism influences the risk of schizophrenia but not bipolar disorder or major depressive disorder: A meta‐analysis
Authors: Gu Lian , Long Jianxiong , Yan Yan , Chen Qiang , Pan Runde , Xie Xinfeng , Mao Xixiang , Hu Xueying , Wei Bo , Su Li 
Published: February 2013

AbstractThe incidence of psychiatric disorders has been shown to have a strong genetic component, and we conducted this study to investigate whether the −1438A/G polymorphism of the HTR2A gene was associated with susceptibility to schizophrenia (SZ), bipolar disorder (BD), and major depressive disorder (MDD). Pooled odd ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using data obtained from a total 27 studies that investigated an association between the HTR2A −1438A/G polymorphism and SZ (15), BD (7), and MDD (4). We failed to observe an association between the HTR2A −1438A/G polymorphism and BD and MDD, and we found contrary results with regard to SZ. Our results showed that the −1438A/G polymorphism was a risk factor for SZ, especially in Caucasians (allele model: OR, 1.12; 95% CI, 1.05–1.20; I2 = 17.3%; dominant model: OR, 1.14; 95% CI, 1.03–1.27; I2 = 15.3%; recessive model: OR, 1.20; 95% CI, 1.06–1.37; I2 = 0.0%; codominant model 1: OR, 1.16; 95% CI, 1.01–1.32; I2 = 0.0%). We found that the association of the HTR2A −1438A/G polymorphism with SZ depends on the ethnic origin of the study population, and this genetic variant does not modify the susceptibility to BD or MDD. © 2013 Wiley Periodicals, Inc.
3,6′‐dithiothalidomide improves experimental stroke outcome by suppressing neuroinflammation
Authors: Yoon Jeong Seon , Lee Jong‐Hwan , Tweedie David , Mughal Mohamed R. , Chigurupati Srinivasulu , Greig Nigel H. , Mattson Mark P. 
Published: February 2013

AbstractTumor necrosis factor‐α (TNF) plays a prominent role in the brain damage and functional deficits that result from ischemic stroke. It was recently reported that the thalidomide analog 3,6′‐dithiothalidomide (3,6′‐DT) can selectively inhibit the synthesis of TNF in cultured cells. We therefore tested the therapeutic potential of 3,6′‐DT in a mouse model of focal ischemic stroke. Administration of 3,6′‐DT immediately prior to a stroke or within 3 hr after the stroke reduced infarct volume, neuronal death, and neurological deficits, whereas thalidomide was effective only when administered prior to stroke. Neuroprotection was accompanied by decreased inflammation; 3,6′‐DT‐treated mice exhibited reduced expression of TNF, interleukin‐1β, and inducible nitric oxide synthase; reduced numbers of activated microglia/macrophages, astrocytes, and neutrophils; and reduced expression of intercellular adhesion molecule‐1 in the ischemic brain tissue. 3,6′‐DT treatment attenuated stroke‐induced disruption of the blood–brain barrier by a mechanism that appears to involve suppression of matrix metalloproteinase‐9 and preservation of occludin. Treatment with 3,6′‐DT did not reduce ischemic brain damage in mice lacking TNF receptors, consistent with a critical role for suppression of TNF production and TNF signaling in the therapeutic action of 3,6′‐DT. These findings suggest that anti‐inflammatory mechanisms underlie the therapeutic actions of 3,6‐DT in an animal model of stroke. © 2013 Wiley Periodicals, Inc.
Organization and maintenance of molecular domains in myelinated axons
Authors: Buttermore Elizabeth D. , Thaxton Courtney L. , Bhat Manzoor A. 
Published: February 2013

AbstractOver a century ago, Ramon y Cajal first proposed the idea of a directionality involved in nerve conduction and neuronal communication. Decades later, it was discovered that myelin, produced by glial cells, insulated axons with periodic breaks where nodes of Ranvier (nodes) form to allow for saltatory conduction. In the peripheral nervous system (PNS), Schwann cells are the glia that can either individually myelinate the axon from one neuron or ensheath axons of many neurons. In the central nervous system (CNS), oligodendrocytes are the glia that myelinate axons from different neurons. Review of more recent studies revealed that this myelination created polarized domains adjacent to the nodes. However, the molecular mechanisms responsible for the organization of axonal domains are only now beginning to be elucidated. The molecular domains in myelinated axons include the axon initial segment (AIS), where various ion channels are clustered and action potentials are initiated; the node, where sodium channels are clustered and action potentials are propagated; the paranode, where myelin loops contact with the axolemma; the juxtaparanode (JXP), where delayed‐rectifier potassium channels are clustered; and the internode, where myelin is compactly wrapped. Each domain contains a unique subset of proteins critical for the domain's function. However, the roles of these proteins in axonal domain organization are not fully understood. In this review, we highlight recent advances on the molecular nature and functions of some of the components of each axonal domain and their roles in axonal domain organization and maintenance for proper neuronal communication. © 2013 Wiley Periodicals, Inc.
Cover‐crop seeding‐date influence on fall nitrogen recovery
Authors: Hashemi Masoud , Farsad Ali , Sadeghpour Amir , Weis Sarah A. , Herbert Stephen J. 
Published: February 2013

AbstractPlanting cover crops after corn‐silage harvest could have a critical role in the recovery of residual N and N from fall‐applied manure, which would otherwise be lost to the environment. Experiments were conducted at the University of Massachusetts Research Farm during the 2004–2006 growing seasons. Treatments consisted of oat and winter rye cover crops, and no cover crop, and four cover‐crop dates of planting. The earliest planting dates of oat and winter rye produced the maximum biomass yield and resulted in the highest nitrate accumulation in both cover‐crop species. The average nitrate accumulation for the 3 years in winter rye and oat at the earliest time of planting was 60 and 48 kg ha–1, respectively. In 2004 where the residual N level was high, winter rye accumulated 119 kg nitrate ha–1. While initially soil N levels were relatively high in early September they were almost zero at all sampling depths in all plots with and without cover crops later in the fall before the ground was frozen. However, in plots with cover crops, nitrate was accumulated in the cover‐crop tissue, whereas in plots with no cover crop the nitrate was lost to the environment mainly through leaching. The seeding date of cover crops influenced the contribution of N available to the subsequent crop. Corn plants with no added fertilizer, yielded 41% and 34% more silage when planted after oat and rye, respectively, compared with the no–cover crop treatment. Corn‐silage yield decreased linearly when planting of cover crops was delayed from early September to early or mid‐October. Corn‐ear yield was influenced more than silage by the species of cover crop and planting date. Similar to corn silage, ear yield was higher when corn was planted after oat. This could be attributed in part to the winter‐kill of oat, giving it more time to decompose in the soil and subsequent greater release of N, while the rapidly increasing C : N ratio of rye can lessen availability to corn plants. Early plantings of cover crops increased corn‐ear yield up to 59% compared with corn‐ear yield planted after no cover crop.
Macro‐ and micronutrient‐release characteristics of three polymer‐coated fertilizers: Theory and measurements
Authors: Adams Curtis , Frantz Jonathan , Bugbee Bruce 
Published: February 2013

AbstractIn spite of several published studies we have an incomplete understanding of the ion‐release mechanisms and characteristics of polymer‐coated fertilizers (PCF). Here we extend current conceptual models describing release mechanisms and describe the critical effects of substrate moisture and temperature on macro‐ and micronutrient release of three PCF types: Polyon®, Nutricote®, and Osmocote®. Nutrient release was quantified at weekly intervals for up to 300 d from 5°C to 40°C in water and chemically inert sand, substrates that allowed release quantification without confounding effects of ion sorption/desorption. At least two release‐timeframe formulations of each PCF type were studied and all products had similar nutrient concentrations to allow isolation of the effect of coating technology. Contrary to several studies, our data and model indicate that there is no significant difference in nutrient‐release rates in water and a moist, solid substrate. This means that release rates determined in water can be used to model bio‐available nutrient concentrations in moist soil or soilless media where sorption/desorption properties alter concentrations after release. Across all PCF, the nutrients most affected by temperature were typically N, K, B, Cu, and Zn, while the least affected were P, Mg, and Fe. We also found consistent differences among the coating technologies. Osmocote fertilizers released faster than specified at both high and low temperatures. Nutricote had relatively steady release rates over time and a nonlinear response to temperature. Polyon released more slowly than specified but replicate samples were highly uniform.
Soil‐moisture change caused by experimental extreme summer drought is similar to natural inter‐annual variation in a loamy sand in Central Europe
Authors: Glaser Bruno , Jentsch Anke , Kreyling Juergen , Beierkuhnlein Carl 
Published: February 2013

AbstractIntensification of weather extremes is currently emerging as one of the most important facets of climate change. Research frontiers are in analyzing (1) the consequences for the hydrological cycle and (2) the effects of multifactor scenarios on ecosystems. However, in all theoretical and experimental scenarios, challenges arise as to how precipitation regimes translate into variation in soil moisture. Here, we explore soil‐moisture response to experimental changes in the precipitation regime in Central Europe over a period of 5 y, particularly focusing on the effects of recurrent extreme weather events. Intraannual difference in weekly precipitation sums imposed by extreme‐drought or heavy‐rainfall manipulations clearly exceeded interannual variation in the ambient precipitation pattern during the growing season between 2005 and 2009. However, soil‐moisture variability in the experimental plots did not clearly reflect any altered patterns in response to the manipulated precipitation regime. Natural variation in soil moisture between years was similar to within‐season differences between manipulations. Strong differences in soil‐moisture dynamics during the growing season can, however, be generated by changing the temporal distribution of rainfall events while keeping the magnitude of the precipitation sum constant. Our findings confirm a common methodological dilemma in precipitation‐change experiments searching for a logical way to determine how precipitation change affects communities and ecosystems on relatively short time scales: Alteration of weather regimes according to extreme‐value statistics and future scenarios vs. systematic alteration of soil moisture. For Central Europe, our data suggest that other factors rather than the magnitude of rainfall exclusion or addition would appear to be decisive for ecosystem response to more extreme precipitation regimes. Response of soil moisture to frequency, return interval, and timing of events is a promising approach for further exploration. In addition, buffer capacity of the ecosystem under study has to be taken into account.
Natural abundance of 18O of sugar biomarkers in topsoils along a climate transect over the Central Scandinavian Mountains, Norway
Authors: Zech Michael , Tuthorn Mario , Glaser Bruno , Amelung Wulf , Huwe Bernd , Zech Wolfgang , Zöller Ludwig , Löffler Jörg 
Published: February 2013

AbstractPrecipitation and topsoil samples from a climate transect over the Scandinavian Mountains, Norway, were analyzed for bulk and compound‐specific δ18O values. The natural abundance of 18O in the plant‐derived hemicellulose biomarkers arabinose and xylose correlates positively with δ18O of bulk soil, but not with δ18O of precipitation. This suggests that other factors than δ18Oprec, such as evaporative 18O enrichment of leaf water, exert a strong influence on the natural abundance of 18O in soils.
Workplace Bullying: Examining Self‐Monitoring and Organizational Culture
Authors: O'Farrell Colin , Nordstrom Cynthia R. 
Published: February 2013

AbstractWorkplace bullying is both prevalent and underresearched. Bullying includes such dysfunctional behavior as sexual harassment, social exclusion, name‐calling, slandering, and physical assaults. Bullying results in negative outcomes for both individual employees and organizations. Individuals experience stress and other physiological and psychological outcomes, and organizations register detrimental effects on productivity, absenteeism, and turnover. This research examined whether employees low in self‐monitoring and working in chaotic organizational cultures were more likely to be victimized by bullies. Results indicated that employees working in chaotic organizations (i.e., lacking transparency, accountability, and appropriate rewards and guidelines) experienced more bullying. Results are discussed with regard to establishing appropriate cultural cues to minimize organizational bullying.