bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic study of cationic dye interactions with clay‐polymer dispersions via metachromatic effect, aggregation, and surface charge
Authors: Davis James W. , Kahl Michael S. , Golden Teresa D. 
Published: November 2013

ABSTRACTInteractions for a series of aqueous dispersions of a clay, Laponite, and nonionic difunctional triblock copolymer, Pluronic L62, with two cationic dyes, crystal violet and brilliant green, are studied using UV–vis spectroscopy, dynamic light scattering (DLS), and electrophoretic mobility (EPM) to better understand the adsorption mechanisms. Different concentrations for clay, 0.1–2.0 g/L, mixed with polymer, 0.125–0.5 g/L to produce an organoclay, were tested with a fixed dye concentration, 2.0 × 10−5mol/L. The aggregation states of the cationic dyes interacting with the clay–polymer dispersions were characterized by UV–vis absorbance. The dyes changed aggregation states from monomer to dimer and higher aggregate states upon addition to varying Laponite–polymer dispersion concentrations. DLS was used to understand the adsorbed polymer and dye interactions on the clay particle showing longer relaxation times for the largest aggregates observed from UV–vis absorbance. The EPM was used to characterize the surface charge of the clay relative to the polymer–dye interactions, which showed that the surface charge approached zero as the dyes interacted with clay–polymer dispersions. The most significant changes occurred with a reduction in light scattering intensity and longer relaxation decay at 0.1 g/L Laponite and 0.5 g/L Pluronic L62 concentrations in the presence of cationic dyes. The study of the clay–polymer–dye interactions help to better understand and design chemical templates for removal of contaminates in waste‐water treatment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 40141.
Preparation and characterization of crosslinked PVAL membranes loaded with boehmite nanoparticles for fuel cell applications
Authors: Oliveira Paula Nunes , Catarino Margarida , Müller Carmem Maria Oliveira , Brandão Lúcia , Pacheco Tanaka David Alfredo , Bertolino José Roberto , Mendes Adélio M. , Pires Alfredo Tibúrcio N. 
Published: November 2013

AbstractComposite proton conducting membranes were prepared by doping the membrane, prepared by crosslinking poly(vinyl alcohol) with sulfosuccinic acid (SSA), with boehmite [aluminum oxyhydroxide or γ‐AlO(OH)]. The effect of the SSA and boehmite content on the membrane performance was studied and the results showed that the values for the ion exchange capacity (IEC) of the membranes were in the range of 0.45–4.80 mmol g−1, the water content and the Young's modulus were dependent on the amount of SSA and nanoparticles. The proton conductivity was in the range of 10−4 to 10−2 S cm−1 at 25°C and was directly related to the quantity of sulfonate groups present in the membrane, while the hydrogen permeability at 30°C was in the range of 10−13 to 10−12 mol cm s−1 cm−2 bar. The proton exchange membrane fuel cell tests indicated that the composite membranes have good proton conductivity and very low hydrogen permeability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40148.
Crosslinked polystyrene beads modified with polar groups for the separation of aromatic/aliphatic hydrocarbons
Authors: Yu Huanyang , Cai Zhenzhen , Liu Xianying , Li Ming , Shi Zuosen , Cui Zhanchen 
Published: November 2013

ABSTRACTCrosslinked polystyrene (CPS) beads modified with polar groups for the separation of aromatic/aliphatic hydrocarbons were successfully prepared. The synthesized beads were characterized by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis. The effects of the crosslinking agents and polar groups on the swelling and selectivity performances toward n‐heptane/toluene mixtures were studied. Impressively, the results indicated that the sulfone‐modified CPS beads obtained a high toluene selectivity. Further adsorption tests with a variety of aromatic/aliphatic hydrocarbons were carried out at 50°C with initial aromatic concentrations of 13 wt %, and the results showed that the beads had a preferential selectivity for aromatic hydrocarbons, in particular, a higher separation factor of 6.76 for benzene/cyclohexane mixtures. We expect that modified CPS beads will serve as an effective material for the selective separation of aromatic/aliphatic hydrocarbons in chemical and petrochemical fields. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40156.
Synchronous Bilateral Adrenalectomy for Cushing’s Syndrome: Laparoscopic Versus Posterior Retroperitoneoscopic Versus Robotic Approach
Authors: Raffaelli Marco , Brunaud Laurent , De Crea Carmela , Hoche Guillaume , Oragano Luigi , Bresler Laurent , Bellantone Rocco , Lombardi Celestino P. 
Published: November 2013

AbstractBackground
Synchronous endoscopic bilateral adrenalectomy (BilA) can effectively provide definitive cure of hypercortisolism in ACTH‐dependent Cushing’s syndrome and in primary adrenal bilateral disease. We compared three different approaches for BilA: transabdominal laparoscopic BilA (TL‐BilA), simultaneous posterior retroperitoneoscopic BilA (PR‐BilA), and robot‐assisted BilA (RA‐BilA).
MethodsAll patients who underwent BilA between January 1999 and December 2012 at two referral centers (one performing TL‐BilA and PR‐BilA and one performing RA‐BilA) were included. A comparative analysis was performed.ResultsTwenty‐nine patients were included: 5 underwent TL‐BilA, 11 underwent PR‐BilA, and 13 underwent RA‐BilA. No significant difference was found concerning age, gender, diagnosis, and previous abdominal surgery. No conversion to open approach was registered. Operative time was significantly shorter for the PR‐BilA group than for the TL‐BilA and RA‐BilA groups (157.4 ± 54.6 vs 256.0 ± 43.4 vs 221.5 ± 42.2 min, respectively) (P < 0.001). No significant difference was found concerning intraoperative and postoperative complications rate and time to first flatus. Drains were used routinely after PR‐BilA and TL‐BilA and electively in four RA‐BilA patients (P < 0.001). Hospital stay was longer in the TL‐BilA and PR‐BilA groups than in the RA‐BilA group (12.0 ± 5.7 vs 10.8 ± 3.7 vs 4.4 ± 1.7 days, respectively) (P < 0.001). No recurrence or disease‐related death was registered.ConclusionsOperative time was significantly shorter in the PR‐BilA group, because it eliminates the need to reposition the patient. The number of drains and the length of hospital stay were reduced after RA‐BilA, but this was likely related to different management protocols in different settings. Because no significant difference was found in terms of postoperative outcome, none of the three operative approaches can be considered the preferable one.
Postoperative Portomesenteric Venous Thrombosis: Lessons Learned From 1,069 Consecutive Laparoscopic Colorectal Resections
Authors: Allaix Marco E. , Krane Mukta K. , Zoccali Marco , Umanskiy Konstantin , Hurst Roger , Fichera Alessandro 
Published: November 2013

AbstractBackground
Portomesenteric venous thrombosis (PVT) is a known complication after open and laparoscopic colorectal (LCR) surgery. Risk factors and the prognosis of PVT have been poorly described.MethodsThis study is a retrospective analysis of a prospectively collected database. Patients with new‐onset postoperative abdominal pain were evaluated with a computed tomography scan of the abdomen. Patients found to have PVT were analyzed. A multivariate analysis was performed to identify predictors of PVT.ResultsA total of 1,069 patients undergoing LCR surgery for inflammatory bowel disease (IBD) or nonmetastatic cancer between June 2002 and June 2012 were included. Altogether, 37 (3.5 %) patients experienced symptomatic postoperative PVT. On univariate analysis, IBD (p < 0.001), ulcerative colitis (p = 0.016), preoperative therapy with steroids (p = 0.008), operative time ≥220 min (p = 0.004), total proctocolectomy (TPC) (p < 0.001), ileoanal pouch anastomosis (p = 0.006), and postoperative intraabdominal septic complications (p < 0.001) were found to be significant risk factors. By multivariate analysis, TPC (p = 0.026) and postoperative intraabdominal septic complications (p < 0.001) were independent predictors of PVT. In the PVT group, postoperative length of stay was longer (14.8 vs. 7.4 days, p < 0.001). Of the patients evaluated with a hematologic workup, 72.7 % were found to have a hypercoagulable condition. All patients were managed with oral anticoagulation for at least 6 months. No death or complications related to PVT occurred.ConclusionsPVT is a potentially serious complication that is more likely to occur after TPC and in the presence of postoperative intraabdominal septic complications, particularly in patients with a coagulation disorder. Prompt diagnosis and treatment with oral anticoagulation are recommended to avoid long‐term sequelae.
Heterogeneous echogenicity of the underlying thyroid parenchyma: how does this affect the analysis of a thyroid nodule?
Authors: Park Mina , Park So Hee , Kim Eun-Kyung , Yoon Jung Hyun , Moon Hee Jung , Lee Hye Sun , Kwak Jin Young 
Published: November 2013

Abstract

Background
Heterogeneous echogenicity of the thyroid gland has been associated with diffuse thyroid disease and benign and malignant nodules can coexist with diffuse thyroid disease. Underlying heterogeneous echogenicity might make it difficult to differentiate between benign and malignant nodules on US. Thus, the aim of this study was to evaluate the influence of underlying thyroid echogenicity on diagnosis of thyroid malignancies using US.

Methods
A total of 1,373 patients who underwent US-guided fine needle aspiration of 1,449 thyroid nodules from June 2009 to August 2009 were included. The diagnostic performance of US assessment for thyroid nodules was calculated and compared according to underlying thyroid echogenicity. The diagnostic performance of US assessments in the diagnosis of thyroid malignancy according to the underlying parenchymal echogenicity was compared using a logistic regression with the GEE (generalized estimating equation) method. Each US feature of malignant and benign thyroid nodules was analyzed according to underlying echogenicity to evaluate which feature affected the final diagnosis.

Results
Among the 1,449 nodules, 325 (22.4%) were malignant and 1,124 (77.6%) were benign. Thyroid glands with heterogeneous echogenicity showed significantly lower specificity, PPV, and accuracy compared to thyroid glands with homogeneous echogenicity, 76.3% to 83.7%, 48.7% to 60.9%, and 77.6% to 84.4%, respectively (P = 0.009, 0.02 and 0.005, respectively). In benign thyroid nodules, microlobulated or irregular margins were more frequently seen in thyroid glands with heterogeneous echogenicity than in those with homogenous echogenicity (P < 0.001).

Conclusion
Heterogeneous echogenicity of the thyroid gland significantly lowers the specificity, PPV, and accuracy of US in the differentiation of thyroid nodules. Therefore, caution is required during evaluation of thyroid nodules detected in thyroid parenchyma showing heterogeneous echogenicity.
Cyclophilin A from Schistosoma japonicum promotes a Th2 response in mice
Authors: Li Jinghui , Zhuang Wenjia , Cong Li , Shi Wenjun , Cai Xingyan , Huang Fengjuan , Liao Yiteng , Liu Yiyang , Li Jun , Chen Chunxia , Chen Xiao-Ping 
Published: November 2013

AbstractBackgroundSchistosomiasis is a chronic infection, where the host immune response to the parasite changes from a predominantly Th1 to Th2 phenotype, when parasite enters the egg stage, restraining the host inflammatory immune responses to achieve a longer survival in the host. On the other hand, the development of Th2 responses causes immunopathological changes such as liver fibrosis. Therefore identification of schistosome-derived Th2 inducing molecules is important in the understanding of pathogenesis of schistosomiasis. A cyclophilin A homologue ofSchistosoma japonicumwas reported to be an egg-stage specific antigen, but its immunogenicity and immunoregulatory activities remain unknown.MethodsWe cloned and expressed the gene of cyclophilin A fromSchistosoma japonicum(AY814078), named as SjCyP18 based on its molecular weight. The expression profiles in different stages ofS. japonicumwere examined by RT-PCR and immunofluorescence assay. The immunogenicity of SjCyP18 was measured by the presence of IgG in the sera fromS. japonicuminfected patients and animals, and the Th2-promting activities were examined by the subclass of immunoglobulins against SjCyP18 and by the IL-4 induction in T cells following footpad injection of SjCyP18.ResultsThe cloned SjCyP18 has 65% homology with human or mouse cyclophilin A at the amino acid level. In contrast to reports as an egg-stage specific antigen, the gene was found to be expressed in all stages ofS. japonicum. IgG responses against SjCyP18 were found in someS. japonicuminfected patients and were significantly induced when infection become patent and produce eggs in infected mice. Furthermore, the Th2-promoting subclass of IgG1 was the predominant isotype inS. japonicuminfected mice. More importantly, footpad injection of SjCyP18 induced a greater production of IL-4 than that of IFN-γ by lymphocytes compared to responses from PBS injection controls.ConclusionThe cyclophilin A homologue found inS. japonicumis immunogenic and promotes Th2 responsesin vivowhich may contribute to the establishment of chronic infection by schistosomes.
Modeling 3‐D density distribution in the mantle from inversion of geoid anomalies: Application to the Yellowstone Province
Authors: Chaves Carlos Alberto Moreno , Ussami Naomi 
Published: November 2013

AbstractWe developed a three‐dimensional scheme to invert geoid anomalies aiming to map density variations in the mantle. Using an ellipsoidal‐Earth approximation, the model space is represented by tesseroids. To assess the quality of the density models, the resolution and covariance matrices were computed. From a synthetic geoid anomaly caused by a plume tail with Gaussian noise added, the inversion code was able to recover a plausible solution about the density contrast and geometry when it is compared to the synthetic model. To test the inversion algorithm in a natural case study, geoid anomalies from the Yellowstone Province (YP) were inverted. From the Earth Gravitational Model 2008 expanded up to degree 2160, lower crust‐ and mantle‐related negative geoid anomalies with amplitude of approximately 70 m were obtained after removing long‐wavelength components (>5400 km) and crustal effects. We estimated three density models for the YP. The first model, the EDM‐1 (estimated density model), uses a starting model with density contrast equal to 0. The other two models, the EDM‐2 and EDM‐3, use an initial density derived from twoS‐velocity models for the western United States, the Dynamic North America Models ofSWaves by Obrebsky et al. (2011) and the Northwestern United States Teleseismic Tomography ofSWaves (NWUS11‐S) by James et al. (2011). In these three models, a lower and an upper bound for the density solution was also imposed as a priori information. Regardless of the initial constraints, the inversion of the residual geoid indicates that the lower crust and the upper mantle of the YP have a predominantly negative density contrast (~ −50 kg/m3) relative to the surrounding mantle. This solution reveals that the density contrast extends at least to 660 km depth. Regional correlation analysis between the EDM‐1 and NWUS11‐S indicates an anticorrelation (coefficient of ~ −0.7) at 400 km depth. Our study suggests that the mantle density derived from the inversion of geoid could be integrated with seismic velocity models to image mantle anomalous features beyond the depth limit of investigation achieved combining gravity and seismic tomography. ©2013. American Geophysical Union. All Rights Reserved.
Poly(2,6‐di(thiophene‐2‐yl)‐3,5bis(4‐(thiophene‐2‐yl)phenyl)dithieno [3,2‐b;2',3'‐d]thiophene)/carbon nanotube composite for capacitor applications
Authors: Ates Murat , Eren Nuri , Osken Ipek , Baslilar Suzan , Ozturk Turan 
Published: November 2013

AbstractA novel monomer, 2,6‐di(thiophene‐2‐yl)‐3,5bis(4‐(thiophene‐2‐yl)phenyl)dithieno[3,2‐b;2',3'‐d]thiophene (Th4DTT) has been synthesized and used as an electro‐active material. It has been electropolymerized onto glassy carbon (GC) electrode in sodium dodecyl sulfate (SDS) solution (0.1 M) together with multi‐walled carbon nanotubes (MWCNT). A good capacitive characteristics for P(Th4DTT)/MWCNT composite has been obtained by electrochemical impedance spectroscopy (EIS), which is, to our best knowledge, the first report on capacitor behavior of a dithienothiophene. A synergistic effect has been resolved by Nyquist, Bode‐magnitude—phase and admittance plots. Specific capacitance of the conducting polymer/MWCNT, calculated from cyclic voltammogram (CV) together with area and charge formulas, has been found to be 20.17 F g−1. Long‐term stability of the capacitor has also been tested by CV, and the results indicated that, after 500 cycles, the specific capacitance is 87.37% of the initial capacitance. An equivalent circuit model of Rs(C1(R1(Q(R2W))))(C2R3) has been obtained to fit the experimental and theoretical data. The double layer capacitance (Cdl) value of P(Th4DTT)/MWCNT (4.43 mF cm−2) has been found to be 25 times higher than P(Th4DTT) (Cdl= 0.18 mF cm−2). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40061.
Improved zein films using polyethylenemaleic anhydride
Authors: Selling Gordon W. , Utt Kelly D. 
Published: November 2013

ABSTRACTThe effect on the physical properties and solubility of corn protein (zein) films was studied after reaction of zein with polyethylenemaleic anhydride (PEMA). Reactions were carried out in dimethylformamide (DMF) solution where the concentration of PEMA was varied between 0 and 6%. After reaction at room temperature, cast films were prepared, and the physical and solubility properties were determined. Incorporating more than 2% PEMA provided films with increased tensile strength and elongation. Incorporating 6% PEMA provided films with higher tensile strength (32–42 MPa) and improved solvent resistance (100–21% solubility) relative to control. If the films were heated in an oven, the film's solubility decreased further. Solution rheology experiments demonstrated that the zein and PEMA formed a cross‐linked gel with time in DMF. Dynamic mechanical analysis experiments have shown that the PEMA‐modified zein films undergo a dramatic loss in modulus on reaching 116°C, whereas the control experiences this loss at 98°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40122.
Mechanism for the formation of PNIPAM/PS core/shell particles
Authors: Zhang Li , Daniels Eric S. , Dimonie Victoria L. , Klein Andrew 
Published: November 2013

ABSTRACTA multi‐stage polymerization method was previously used to prepare PNIPAM/PS core/shell particles that exhibited uniform “raspberry‐like” structures. In this current study, this polymerization process was carefully investigated in order to elucidate the PS (polystyrene) shell formation mechanism. The results indicated that the “raspberry” structure is due to heterocoagulation of polystyrene domains onto PNIPAM (poly(N‐isopropylacrylamide)) particle surfaces. Different sizes and numbers of the PS domains can be obtained by varying the styrene feed rate. It was also found that linear PNIPAM may increase the compatibility between PNIPAM and PS polymers. In addition, this heterocoagulation mechanism for forming structured particles was successfully applied to a PNIPAM and Ludox® colloidal silica nanoparticle system where a core/shell structure was also obtained. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40124.
Influence of copolymer fraction composition in ultrahigh molecular weight polyethylene blends with ethylene/1‐hexene copolymers on material physical and tensile properties
Authors: Ushakova T. M. , Starchak E. E. , Krasheninnikov V. G. , Grinev V. G. , Ladygina T. A. , Novokshonova L. A. 
Published: November 2013

AbstractThe reactor blends (RBs) with bimodal molecular weight distribution on the base of ultrahigh molecular weight polyethylene (UHMWPE) and low molecular weight random ethylene/1‐hexene copolymers (CEH) were synthesized by two‐step processes including ethylene polymerization followed by ethylene/1‐hexene copolymerization over rac‐(CH3)2Si(Ind)2ZrCl2/methylaluminoxane catalyst. The four series of blends differed in a composition of copolymer fraction that was varied in a wide range (from 3.0 to 37.0 mol % of 1‐hexene). The differential scanning calorimetric study shows the double melting behavior of the net semicrystalline CEHs, which can be attributed to intramolecular heterogeneity in chain branch distribution. The introduction of CEHs leads to the modification of nascent RB crystalline and amorphous phases. Physical and tensile properties as well as melting indexes of the materials depend not only on the percentage of copolymer fraction that varied from 6.9 to 35.8 wt % but also on its composition. The increase of copolymer fraction with high content of 1‐hexene (≥11.0 mol %) in the blends leads to the change of the character of stress–strain curves; the materials behave as elastomers. Controlled regulation of copolymer fraction characteristics in the synthesis yields RBs combining the enough high strength, good plastic properties with enhanced melting indexes as compared with the net UHMWPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40151.
A focused assignment encouraging deep reading in undergraduate biochemistry
Authors: Spiegelberg Bryan D. 
Published: November 2013

AbstractEncouraging undergraduate students to access, read, and analyze current primary literature can positively impact learning, especially in advanced courses. The incorporation of literature into coursework typically involves reading and responding to full research reports. Such exercises have clear value as students make connections between experiments and are able to probe and critique scientific logic. The exclusive use of full papers, though, may reinforce certain students' tendencies to rely on textual clues rather than a critical analysis of the actual data presented. I propose that structured activities requiring students to focus on individual parts of research papers, even on a single figure, are beneficial in a literature‐centered advanced undergraduate course, because they promote the deep reading that is critical to scientific discourse. In addition, I describe how one such focused assignment boosted learning and was well received by students in a second‐semester biochemistry course. © 2013 by The International Union of Biochemistry and Molecular Biology, 42(1):1–5, 2014