bluuebunny/crossref_metadata_2025 huggingface dataset:
Isothermal Kinetics of Catalyzed Air Oxidation of Diesel Soot
Authors: Prasad Ram , Bella Venkateswara Rao
Published: October 2012

To comply with the stringent emission regulations on soot, diesel vehicles manufacturers more and more commonly use diesel particulate filters (DPF). These systems need to be regenerated periodically by burning soot that has been accumulated during the loading of the DPF. Design of the DPF requires rate of soot oxidation. This paper describes the kinetics of catalytic oxidation of diesel soot with air under isothermal conditions. Kinetics data were collected in a specially designed mini-semi-batch reactor. Under the high air flow rate assuming pseudo first order reaction the activation energy of soot oxidation was found to be, Ea = 160 kJ/ mol. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Catalytic Hydrogenation of Acetone to Isopropanol: An Environmentally Benign Approach
Authors: Rahman Ateeq
Published: October 2012

The catalytic hydrogenation of acetone is an important area of catalytic process to produce fine chemicals. Hydrogenation of acetone has important applications for heat pumps, fuel cells or in fulfilling the sizeable demand for the production of 2-propanol. Catalytic vapour phase hydrogenation of acetone has gained attention over the decades with variety of homogeneous catalysts notably Iridium, Rh, Ru complexes and heterogeneous catalysts comprising of Raney Nickel, Raney Sponge, Ni/Al2O3, Ni/SiO2, or Co-Al2O3, Pd, Rh, Ru, Re, or Fe/Al2O3 supported on SiO2 or MgO) and even CoMgAl, NiMg Al layered double hydroxide, Cu metal, CuO, Cu2O. Nano catalysts are developed for actone reduction Ni maleate, cobalt oxide prepared in organic solvents. Author present a review on acetone hydrogenation under different conditions with various homogeneous and heterogeneous catalysts studied so far in literature and new strategies to develop economic and environmentally benign approach. © 2010 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
A Review on Preferential Oxidation of Carbon Monoxide in Hydrogen Rich Gases
Authors: Mishra A. , Prasad Ram
Published: October 2012

In this review, recent works on the preferential oxidation of carbon monoxide in hydrogen rich gases for fuel cell applications are summarized. H2 is used as a fuel for polymer-electrolyte membrane fuel cell (PEMFC). It is produced by reforming of natural gas or liquid fuels followed by water gas shift reaction. The produced gas consists of H2, CO, and CO2. In which CO content is around 1%, which is highly poisonous for the Pt anode of the PEMFC so that further removal of CO is needed. Catalytic preferential oxidation of CO (CO-PROX) is one of the most suitable methods of purification of H2 because of high CO conversion rate at low temperature range, which is preferable for PEMFC operating conditions. Catalysts used for COPROX are mainly noble metal based; gold based and base metal oxide catalysts among them Copper-Ceria based catalysts are the most appropriate due to its low cost, easy availability and result obtained by these catalysts are comparable with the conventional noble metal catalysts. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Fuzzy Modeling to Evaluate the Effect of Temperature on Batch Transesterification of Jatropha Curcas for Biodiesel Production
Authors: Sohpal Vipan Kumar , Singh Amarpal , Dey Apurba
Published: October 2012

Biodiesel is an alternative source of fuel that can be synthesized from edible, non-edible and waste oils through transesterification. Firstly Transesterification reaction of Jatropha Curcas oil with butanol in the ratio of 1:25 investigated by using of sodium hydroxide catalyst with mixing intensity of 250 rpm in isothermal batch reactor. Secondly the fuzzy model of the temperature is developed. Performance was evaluated by comparing fuzzy model with the batch kinetic data. Fuzzy models were developed using adaptive neurofuzzy inference system (ANFIS). © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Modified Mathematical Model For Neutralization System In Stirred Tank Reactor
Authors: Ibrehem Ahmmed Saadi
Published: October 2012

A modified model for the neutralization process of Stirred Tank Reactors (CSTR) reactor is presented in this study. The model accounts for the effect of strong acid [HCL] flowrate and strong base [NaOH] flowrate with the ionic concentrations of [Cl-] and [Na+] on the Ph of the system. In this work, the effect of important reactor parameters such as ionic concentrations and acid and base flowrates on the dynamic behavior of the CSTR is investigated and the behavior of mathematical model is compared with the reported models for the McAvoy model and Jutila model. Moreover, the results of the model are compared with the experimental data in terms of pH dynamic study. A good agreement is observed between our model prediction and the actual plant data. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
System Identification for Experimental Study for Polymerization Catalyst Reaction in Fluidized Bed
Authors: Ibrehem Ahmmed S.
Published: October 2012

In this work, system identification method is used to capture the reactor characteristics of production rate of polyethylene (PE) based on published experimental data. The identification method is used to measure the percentage effect on the production rate of PE by measuring the effect of input factors of temperature of reaction, hydrogen concentration, and [Al]/[Ti] molar catalyst ratio. Temperature of reaction has big effects equal 52.4 % on the output of the system and 47.6 % on interaction of the system's parameters compare to other two factors. Also, hydrogen concentration has big effect equal 45.66 % on the output of the system and 14.7 % on interaction of the system's parameters. [Al]/[Ti] molar catalyst ratio has big effect on interaction of the system equal 28.6 and 1.94 % on the output of the system but less than the reaction temperature and hydrogen concentration. All these results depend on experiment results and these results are very important in industrial plants. © 2011 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
The Role of Sulfur in Solution‐Processed Cu2ZnSn(S,Se)4 and its Effect on Defect Properties
Authors: Duan Hsin‐Sheng , Yang Wenbing , Bob Brion , Hsu Chia‐Jung , Lei Bao , Yang Yang
Published: October 2012

Understanding the electrically active defects in kesterite Cu2ZnSn(S,Se)4(CZTSSe) is critical for the continued development of solar cells based on this material, but challenging due to the complex nature of this polycrystalline multinary material. A comparative study of CZTSSe alloys with three different bandgaps, made by introducing different fractions of sulfur during the annealing process, is presented. Using admittance spectroscopy, drive level capacitance profiling, and capacitance‐voltage profiling, the dominant defect energy level present in the low sulfur content device is determined to be 0.134 eV above the valence band maximum, with a bulk defect density of 8 × 1014 cm−3, while the high sulfur content device shows a deeper defect energy level of 0.183 eV and a higher bulk defect density, 8.2 × 1015 cm−3. These findings are consistent with the current density–voltage characteristics of the resulting solar cells and their external quantum efficiency. It suggests that as the sulfur content increases, the bandgap of the absorber is enlarged, leading to an increasing open‐circuit voltage (Voc), that is accompanied by stronger recombination due to the higher defect density of the sulfur‐rich absorber. This is reflected in large Voc deficit and poor carrier collection of the high sulfur content device.
Interaction of Ferromagnetic Shape Memory Alloys and RGD Peptides for Mechanical Coupling to Cells: from Ab Initio Calculations to Cell Studies
Authors: Zink Mareike , Szillat Florian , Allenstein Uta , Mayr Stefan G.
Published: October 2012

Due to their magneto‐mechanical coupling and biocompatibility, Fe‐Pd based ferromagnetic shape memory alloys are a highly promising materials class for application as contact‐less magneto‐mechanical transducers in biomedical environments. For use in cell and tissue actuators or strain sensors, sufficient adhesion to mediate strains clearly constitutes a prerequisite. As the RGD sequence is the most important binding motif for mammalian cells, which they express to facilitate adhesion, the potential of RGD coatings to achieve this goal is explored. Employing large‐scale density functional theory calculations the physics of bonding between RGD and Fe‐Pd surfaces, which is characterized by coordinate bonds of O and N atoms to Fe, accompanied by electrostatic contributions, is clarified. Theoretical predictions on adhesion, that are confirmed experimentally, suggest RGD as suitable strain mediator to Fe‐Pd surfaces. On the cell side, favorable adhesion properties of RGD‐coated Fe‐Pd are manifested in cell morphology and spreading behavior. Demonstrating that the adhesion forces between RGD and Fe‐Pd exceed those exerted by cells to the RGD coating, as well as traction forces acting onto integrin bonds, the findings pave the way for novel type of applications as cell and tissue actuator or sensor within the areas of tissue engineering and regenerative medicine.
Nanoparticle Stacks with Graded Refractive Indices Enhance the Omnidirectional Light Harvesting of Solar Cells and the Light Extraction of Light‐Emitting Diodes
Authors: Fang Cheng‐Yi , Liu Yu‐Lun , Lee Yang‐Chun , Chen Hsuen‐Li , Wan De‐Hui , Yu Chen‐Chieh
Published: October 2012

In this study, nanoparticles (NPs) of various types and sizes are arranged to enhance both the omnidirectional light harvesting of solar cells and the light extraction of light emitting diodes (LEDs). A graded‐refractive‐index NP stack can minimize reflectance, not only over a broad range of wavelengths but also at different incident angles; the photocurrent of silicon‐based solar cells an also be significantly improved omnidirectionally. In addition, the optical gradient of an NP stack can also enhance the light‐extraction efficiency of LEDs, due to both the graded refractive index and the moderate surface roughness. Large particles having sizes on the same order of the wavelength of the incident light roughen the LED surfaces further and extract light from beyond the critical angle, as supported by three‐dimensional finite‐difference time‐domain simulations. Using this approach, the photoluminescence intensity can be increased by up to sevenfold. The developed technique: arranging sequences of different NPs in graded‐refractive‐index stacks, and considering their ability to scatter light due to their sizes and optical constants, may also significantly improve the performance of various optoelectronic devices.
Drag force and clustering in bubble swarms
Authors: Roghair Ivo , Van Sint Annaland Martin , Kuipers Hans J. A. M.
Published: October 2012

In this article, results of detailed numerical simulations are reported meant to provide a closure relation for the drag force acting on bubbles rising in a dense swarm. The formation of clusters of bubbles in a periodic domain and the effect thereof on the rise velocity and effective drag coefficient on the bubbles are studied. Using smaller bubble sizes than presented in our earlier work, we are also able to refine our correlation for the drag coefficient acting on bubbles rising in a swarm, such that it is applicable for a large range of bubble sizes. The simulations are performed with an advanced Front‐Tracking model in which Lagrangian marker points are used to track the gas–liquid interface, while accounting for surface tension and substantial interface deformation. Simulations were performed using periodic domains to simulate rising air bubbles in water from 1.0 mm up to 6.0 mm in diameter. The effect of liquid phase viscosity was also studied to extend the range of validity of the drag correlation. For the 1.0 and 1.5 mm cases, strong horizontal clustering effects are observed. Especially, at high gas fractions, the bubbles tend to form rigid horizontal arrays, which have been shown to strongly increase the drag force acting on the bubbles in the cluster. For viscous liquids, the tendency to form horizontal clusters is lower, and even vertical clustering is observed. The bubble slip velocity was compared with the experimental results of Zenit et al., which agree very well taking into account the differences between simulations and experiments. Based on our simulations, a new drag correlation was proposed, taking into account Eötvös numbers ranging from 0.13 to 4.9, and Morton numbers in the range 3.8 ≤ − log Mo < 6.6, and gas hold‐ups up to 40% (30% for Eo < 0.3). At lower values for −log Mo, the Reynolds number drops to the order of unity, and the correlation overpredicts the drag coefficient, which defines the range of applicability of the currently proposed drag correlation. The correlation itself describes a linear increase of the normalized drag coefficient as a function of the gas hold‐up. The strength of linear increase is stronger at lower Eötvös numbers. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1791–1800, 2013
Fibroblast growth factor receptor 1 (FGFR1) variants and craniofacial variation in Amerindians and related populations
Authors: Gómez‐Valdés Jorge A. , Hünemeier Tábita , Contini Verônica , Acuña‐Alonzo Victor , Macin Gastón , Ballesteros‐Romero Mónica , Corral Pau , Ruiz‐Linares Andres , Sánchez‐Mejorada Gabriela , Canizales‐Quinteros Samuel , Martínez‐Abadías Neus , Salzano Francisco M. , González‐José Rolando , Bortolini Maria cátira
Published: October 2012

Objectives:

The polymorphic site rs4647905 of the FGFR1 gene was previously associated with a decrease in cephalic index (CI). Here, we evaluate the relationships between genotypes and cephalometric measurements and indices in one Mexican Native and two mestizo Mexican populations using two haplotype‐tag SNPs (rs4647905 and rs3213849) that represent >85% of the FGFR1 variability, plus three other SNPs (rs2293971, rs2304000, and rs930828) situated nearby. In addition, we genotyped five South American natives, two European, one African, and one Siberian populations to evaluate their intra and intercontinental population diversity.

Methods:

The five SNPs were tested and the craniofacial measurements and indices were collected using standardized procedures. Principal Component Analysis was used to verify individual/population comparisons. Associations were performed through the generalized linear model (GLM), coefficient of determination R2 and linear regression tests.

Results:

We found a tendency for a decrease in CI in individuals homozygous for allele rs4647905C, regardless of the population to which they belong, though the effect is more pronounced in mestizo. When the GLM analyses were performed using the absolute/linear cephalometric measurements, a statistically significant association was found between four SNPs and head length in the mestizo population.

Conclusions:

FGFR1 polymorphisms, especially rs4647905, can have an important role in the normal human skull variation, primarily due to their influence in head length, which would affect other cephalometric absolute/linear measures as well as indices like CI as a result of the pervasive nature of the morphological integration that characterizes the human skull. Am. J. Hum. Biol. 2013. © 2012 Wiley Periodicals, Inc.
SERS Detection of Small Inorganic Molecules and Ions
Authors: Alvarez‐Puebla Ramón A. , Liz‐Marzán Luis M.
Published: October 2012

Surface‐enhanced Raman scattering (SERS) is one of the most straightforward applications of the so‐called nanoplasmonics. This powerful molecular spectroscopy technique is based on the enhancement of the inelastic scattering from molecules located near nanostructured metallic surfaces when these are illuminated and surface plasmons are excited. The analytical applications of SERS are hindered when the Raman cross‐section of the analyte is too low, which is often the case in inorganic molecular species. This problem is even more serious when atomic species are to be identified, since these cannot display a vibrational signal. Herein we discuss the recent advancements toward the SERS detection of small inorganic compounds, including both molecular and atomic species.
Antifouling microfiltration membranes prepared from poly(vinylidene fluoride)‐graft‐Poly(N‐ vinyl pyrrolidone) powders synthesized via pre‐irradiation induced graft polymerization
Authors: Chen Lifang , Hou Zhengchi , Lu Xiaofeng , Chen Peng , Liu Zhongying , Shen Liguo , Bian Xiaokai , Qin Qiang
Published: October 2012

Poly(vinylidene fluoride) (PVDF) powders were grafted with N‐vinyl pyrrolidone using the pre‐irradiation induced graft polymerization technique. The effects of reaction time, absorbed dose, and monomer concentration on the degree of grafting were investigated, and the grafted PVDF powders were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The grafted PVDF powders were also cast into microfiltration (MF) membranes via the phase‐inversion method. The contact angle and water uptake were measured. The membrane morphology was studied by scanning electron microscopy, and the water filtration properties of the membranes were tested. The antifouling properties were determined through measurements of the recovery percentage of pure water flux after the MF membranes were fouled with bovine serum albumin solution. The results confirmed that the existence of poly(N‐vinyl pyrrolidone) (PVP) graft chains improved the hydrophilicity and antifouling properties of the MF membranes cast from PVDF‐g‐PVP powders. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
13C‐NMR, 13C‐13C gCOSY, and ESI‐MS characterization of ether‐bridged condensation products in N,N′‐dimethylurea‐formaldehyde systems
Authors: Kibrik Éléonore J. , Steinhof Oliver , Scherr Günter , Thiel Werner R. , Hasse Hans
Published: October 2012

The reaction of urea with formaldehyde is the basis for the production of urea‐formaldehyde (UF) resins which are widely applied in the wood industry. The presence of ether‐bridged condensation products in the UF resin reaction system is an open question in the literature. It is addressed in the present work. The N,N′‐dimethylurea‐formaldehyde model system was studied since it is chemically similar to the UF resin reaction system but allows for a simple elucidation of all reaction products. It was analyzed by 13C‐NMR spectroscopy and ESI‐MS. In corresponding NMR and MS spectra, peaks due to methoxymethylenebis(dimethyl)urea and its hemiformal were observed. 13C‐13C gCOSY analysis was conducted using labeled 13C‐formaldehyde. The correlation spectra showed evidence for an ether‐bridged compound and mass spectra exhibited peaks agreeing with labeled methoxymethylenebis(dimethyl)urea and its hemiformal. Methoxymethylenebis(dimethyl)urea was characterized in N,N′‐dimethylurea‐formaldehyde systems in acidic and slightly basic media. As urea is very similar to N,N′‐dimethylurea, the results of this work strengthen the assumption that ether‐bridged condensation products are likely to form in UF resins. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Proximal Femoral Musculoskeletal Morphology of Chimpanzees and its Evolutionary Significance: A Critique of Morimoto et al. (2011)
Authors: Suwa Gen , Lovejoy C. Owen , Asfaw Berhane , White Tim
Published: October 2012

Based on the analysis of computed tomography (CT) scan imagery, Morimoto et al. (Anatomical Record 2011; 294:1433–1445) concluded that the proximal femoral shaft attachment of the chimpanzee gluteus maximus (GM) lies in a position similar to that of modern humans (medial to a longitudinal bony structure that runs superoinferiorly along the lateral proximal shaft), contradicting the previous reports of similarity with the other extant apes. Based on a broader comparative osteological perspective and examination of some of the same CT imageries, we here demonstrate that: 1) although the chimpanzee insertion of the GM appears to lie more posteromedially than it does in gorillas and orangutans, the validity of the extent of this reassessment remains in doubt, pending crossvalidation of CT analyses by parallel dissections of the imaged specimens, and 2) the chimpanzee and human conditions are, nevertheless, distinct. We agree with Morimoto et al. (Anatomical Record 2011; 294:1433–1445) that these observations support the interpretation that superficially similar osteological topographies of the proximal femur were acquired independently by chimpanzees and gorillas, but we disagree about the significance of their suggested human–chimpanzee similarities. Although Morimoto et al. (Anatomical Record 2011; 294:1433–1445) considered these to be shared‐derived features of the chimpanzee–human clade, we instead argue that the shared absence of strong anterolateral displacement of the GM attachment among chimpanzees, basal hominids (such as Orrorin and Ardipithecus), and humans likely reflects the primitive condition characteristic of a wide range of Miocene apes. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Using site‐level connections to estimate link confidence
Authors: Souza Jucimar , Carvalho André , Cristo Marco , Moura Edleno , Calado Pavel , Chirita Paul‐Alexandru , Nejdl Wolfgang
Published: October 2012

Search engines are essential tools for web users today. They rely on a large number of features to compute the rank of search results for each given query. The estimated reputation of pages is among the effective features available for search engine designers, probably being adopted by most current commercial search engines. Page reputation is estimated by analyzing the linkage relationships between pages. This information is used by link analysis algorithms as a query‐independent feature, to be taken into account when computing the rank of the results. Unfortunately, several types of links found on the web may damage the estimated page reputation and thus cause a negative effect on the quality of search results. This work studies alternatives to reduce the negative impact of such noisy links. More specifically, the authors propose and evaluate new methods that deal with noisy links, considering scenarios where the reputation of pages is computed using the PageRank algorithm. They show, through experiments with real web content, that their methods achieve significant improvements when compared to previous solutions proposed in the literature.
Ammonia plasma treatment of polystyrene surfaces enhances proliferation of primary human mesenchymal stem cells and human endothelial cells
Authors: Kleinhans Claudia , Barz Jakob , Wurster Simone , Willig Marleen , Oehr Christian , Müller Michael , Walles Heike , Hirth Thomas , Kluger Petra J.
Published: October 2012

The control of surface properties is a substantial step in the development and improvement of biomaterials for clinical applications as well as for their use in tissue engineering. Interaction of the substrate surface with the biochemical or biological environment is crucial for the outcome of the applied biomaterial and therefore should meet specific requirements regarding the chemical composition, wettability, elasticity, and charge. In this study, we examined the effect of chemical groups introduced by low pressure plasma treatments of polystyrene surfaces on the cell behavior of primary human mesenchymal stem cells (hMSCs) and dermal microvascular endothelial cells (hDMECs). X‐ray photoelectron spectroscopy analysis and contact angle measurements were employed to evaluate ammonia‐, carbon dioxide‐, and acrylic acid‐plasma modifications to substrate surfaces. HMSCs and hDMECs were analyzed simultaneously to identify the most suitable surface functionalization for each cell type. Significantly higher cell proliferation was detected on ammonia plasma‐treated surfaces. Cell‐material interaction could be shown on all created interfaces as well as the expression of typical cell markers. Hence, the applied plasma treatment presents a suitable tool to improve culture condition on polystyrene for two important cell types (hMSCs and hDMECs) in the field of tissue engineering.
Gold nanograin microelectrodes for neuroelectronic interfaces
Authors: Kim Raeyoung , Hong Nari , Nam Yoonkey
Published: October 2012

Neuroelectronic interfaces are imperative in investigating neural tissues as electrical signals are the main information carriers in the nervous system and metal microelectrodes have been widely used for recording and stimulation of nerve cells. For high performance microelectrodes, low tissue‐electrode interfacial impedance and high charge injection limits are essential and nanoscale surface engineering has been utilized to meet the requirements for microelectrodes. We report a single‐cell sized microelectrode, which has unique gold nanograin structures, using a simple electrochemical deposition method. The fabricated microelectrode had a sunflower shape with 1–5 (m of micropetals along the circumference of the microelectrode and 500 nm nanograins at the center. The nanograin electrodes had 69‐fold decrease of impedance and 10‐fold increase in electrical stimulation capability compared to unmodified flat gold microelectrodes. The recording and stimulation performance of nanograin electrodes was tested using dissociated rat hippocampal neuronal cultures. Noise levels were extremely low (2.89 μVrms) resulting in high signal‐to‐noise ratio for low‐amplitude action potentials (18.6–315 μV). Small biphasic current pulses (20–60 μA) could evoke action potentials from neurons nearby electrodes. This new nanostructured neural electrode may be applicable for the development of cell‐based biosensors or clinical neural prosthetic devices.
The effect of ultrasonication on the immunomodulatory activity of low‐quality ginseng
Authors: Seo Yong Chang , Song Chi Ho , Lim Hye Won , Lee Hyeon Yong
Published: October 2012

This study investigated the effects of ultrasonication extraction (UE) on the immunomodulatory activity of low‐quality ginseng. The results indicate that the optimal conditions for extracting low‐quality ginseng are ultrasonication at 60 kHz and 85°C for 60 min. The extraction yield from the UE was 20% higher than that of the water extraction (WE) at 100°C. The low quality ginseng obtained from the UE exhibited relatively low cytotoxicity toward normal human cells, with an observed toxicity of 15–18% at a concentration of 1.0 mg/mL. The ginseng product obtained following UE induced human B and T cells growth and resulted in concentrations of up to 9.33 × 104 cells/mL and 15.33 × 104 cells/mL, respectively. The ginseng extract also increased the secretion of interleukin‐6 and tumor necrosis factor‐α from these cells by up to 35%, and natural killer/ cell growth was also improved by up to 30%. The UE effectively released 2‐ to 3‐fold higher levels of ginsenosides than the WE. Specifically, the obtained levels of Rb1, Re, and Rg1, which are likely immunomodulatory factors, were approximately three times higher after ultrasonication than after WE. These results were further supported by the finding that UE product‐treated macrophages produced higher levels of nitric oxide (21 μM) than macrophages treated with the WE product or with standard ginsenosides. These results demonstrate that this optimized ultrasonication process effectively destroyed the more rigid cell walls of low‐quality ginseng and released high levels of ginsenosides. This work is the first to correlate extraction parameters with both extraction yields and biological activity. The use of low‐quality ginseng can thus be expanded by utilizing a low‐temperature ultrasonic extraction process. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Shrimp (Litopenaeus vannamei) trypsinogen production in Pichia pastoris bioreactor cultures
Authors: Viader‐Salvadó José M. , Fuentes‐Garibay José A. , Castillo‐Galván Mauricio , Iracheta‐Cárdenas María M. , Galán‐Wong Luis J. , Guerrero‐Olazarán Martha
Published: October 2012

Recently, we engineered a Pichia pastoris Mut+ strain to produce and secrete recombinant Litopenaeus vannamei trypsinogen. Despite the observed toxicity of the recombinant shrimp trypsinogen to the P. pastoris cell host, when high density cell cultures in shake flasks with alanine in the induction medium were used recombinant shrimp trypsinogen could be produced. To further improve the product yield, in this work, we evaluated L. vannamei trypsinogen production in P. pastoris using a bioreactor and two recombinant P. pastoris strains with different methanol utilization (Mut) phenotypes. The effect of pH and temperature during the induction step on the trypsinogen production was also evaluated. The results indicate that temperature, pH, and Mut phenotypes influence the production of the recombinant protein, with almost no observed effect on cell growth. All cultures with the Mut+ strain had significant operational difficulties, such as in lowering the induction temperature, maintaining dissolved oxygen (DO) above 20%, and maintaining the methanol concentration at a constant value, and showed a decrease in metabolic activity due to trypsinogen toxicity to the cell host. In the culture with the Muts strain, however, the temperature, methanol concentration, and DO could be more easily controlled, the temperature could be easily decreased, and the trypsinogen caused the lowest toxicity to the host cells. After 96 h of Muts strain induction (pH 6 and 25°C), about 250 mg/L recombinant trypsinogen was detected in the culture medium. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Phosphatidylcholine enrichment with medium chain fatty acids by immobilized phospholipase A1‐catalyzed acidolysis
Authors: Ochoa Angélica A. , Hernández‐Becerra Josafat A. , Cavazos‐Garduño Adriana , García Hugo S. , Vernon‐Carter Eduardo J.
Published: October 2012

Phospholipids are a biologically and industrially important class of compounds whose physical properties can be improved for diverse applications by substitution of medium‐chain fatty acids for their native fatty acid chains. In this study, phosphatidylcholine (PC) was enriched with medium‐chain fatty acids (MCFAs) by acidolysis with phospholipase A1 (PLA1) immobilized on Duolite A568. Response surface methodology was employed to evaluate the effects of the molar ratio of substrates (PC to free MCFAs), enzyme loading, and reaction temperature on the incorporation of free MCFAs into PC and on PC recovery. Enzyme loading and molar ratio of substrates contributed positively, but temperature negatively, to the incorporation of free MCFAs into PC. Increases in enzyme loading and the molar ratio of PC to free MCFAs led to increased incorporation of the latter into the former, but increased temperature had the opposite effect. By contrast, an increase in enzyme loading led to decreased PC recovery. Increased temperature had also a negative effect on PC recovery. Optimal conditions for maximum incorporation and PC recovery were molar ratio of PC to free MCFAs of 1:16, enzyme loading of 16%, and 50°C. Under these conditions, the incorporation of free MCFAs was 41% and the PC recovery was 53%. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2013
Incidence and clinical impact of concurrent chronic total occlusion according to gender in ST‐Elevation myocardial infarction
Authors: Bataille Yoann , Déry Jean‐Pierre , Larose Éric , Abdelaal Eltigani , Machaalany Jimmy , Rodés‐Cabau Josep , Rinfret Stéphane , Déry Ugo , Costerousse Olivier , Roy Louis , Bertrand Olivier F.
Published: October 2012

Objectives

To determine the prevalence of a concurrent CTO in men and women and to examine its impact on mortality.

Background

The impact of chronic total occlusion (CTO) in patients with ST‐elevation myocardial infarction (STEMI) according to gender has not been assessed.

Methods

Patients referred with STEMI were categorized into single vessel disease (SVD), multivessel disease (MVD) without, with 1 or > 1 CTO. The primary end‐point was the 1‐year mortality.

Results

Among the 2020 STEMI patients included between 2006 and 2011, 24% were female. Women were older, had more hypertension and renal failure (P < 0.0001 for all). The prevalence of 1 or > 1 concurrent CTO was similar in both sexes, 7 and 1%, respectively. Early and late mortality was significantly higher in women compared with men (P < 0.0001). In women, the mortality was significantly worse in patients with > 1 CTO (100%) and with 1 CTO (36.4%) compared with those with MVD without CTO (18.4%) or with SVD (10.4%) (P < 0.0001). MVD with and without concurrent CTO were both independent predictors of 1‐year mortality in women (HR 3.58; 95 % CI 1.69–7.18 and HR 2.76; 95 % CI 1.33–5.51) whereas only MVD with CTO was predictive in men (HR 2.19; 95% CI 1.20–3.97).

Conclusions

Among unselected STEMI patients, the prevalence of CTO was equal in both sexes whereas early and late mortality remained significantly higher in women. Other factors than the presence of a concurrent CTO must be explored to explain differences in survival after STEMI between women and men. © 2013 Wiley Periodicals, Inc.
Percutaneous transvenous tricuspid commissurotomy in a patient with congenitally corrected transposition of great arteries
Authors: Chaurasia Ajay , Nawale Jaywant , Yemul Madhusudan , Patil Sandeep , Mukhedkar, Sachin
Published: October 2012

Percutaneous balloon tricuspid valvotomy was successfully performed in a 45‐year‐old female with congenitally corrected transposition of great arteries with severe rheumatic left atrioventricular (tricuspid) valve stenosis. Technical modifications in the standard procedure were made keeping in mind the left‐handed ventricular loop, left and anterior aorta, wedged pulmonary valve between the interatrial septum and the mitral valve with deviation of the atrial septum away from the ventricular septum, side‐by‐side positioned ventricles with an added superoinferior obliquity produced by excessive tilting, and an abnormal orientation of ventricular mass in relation to the thorax, with the apex pointing slightly rightwards. A final valve area of 1.4 cm2 and a fall in the peak/mean left atrial pressures from 37/32 mm Hg to 13/10 mm Hg were achieved without complications. This case of percutaneous transvenous commissurotomy is unique in view of the rarity of the combination of this congenital heart disease and rheumatic heart disease and successful commissurotomy in such an unusual cardiac anatomy using the Inoue technique.© 2012 Wiley Periodicals, Inc.
Is euroscore II better than EuroSCORE in predicting mortality after transcatheter aortic valve implantation?
Authors: Watanabe Yusuke , Hayashida Kentaro , Lefèvre Thierry , Chevalier Bernard , Hovasse Thomas , Romano Mauro , Garot Philippe , Farge Arnaud , Donzeau‐Gouge Patrick , Bouvier Erik , Cormier Bertrand , Morice Marie‐Claude
Published: October 2012

Objectives

The purpose of this study was to examine the performance of the European system for cardiac operative risk evaluation II (ESII) in patients undergoing transcatheter aortic valve implantation (TAVI).

Background

The ESII was developed recently to improve the predictive value of the original logistic EuroSCORE (LES).

Methods

Between October 2006 and November 2011, 453 consecutive patients with severe aortic stenosis undergoing TAVI with either the Edwards valve or the Corevalve were included in the current analysis. The performance of the ESII, LES, and society of thoracic surgeons predicted risk of mortality score (STS) was evaluated.

Results

Mean age was 83.1 ± 6.4 years. The Edwards valve was used in 382 patients (84.3%) of the cohort, transfemoral approach (TF) in 55.0%, transapical approach (TA) in 25.2%, transaortic approach (TAo) 17.8%, transsubclabian approach (SC) 2.0%. The observed 30‐day mortality was 12.6% (11.2, 18.4, 7.4, and 22.2% for TF, TA, TAo, SC, respectively). The mean LES, STS, and ESII were 22.4 ± 12.1, 8.1 ± 6.0, and 8.1 ± 5.2, respectively. The Hosmer–Lemeshow test showed ESII was inadequately calibrated for 30‐day mortality compared with other risk scores (ESII P = 0.09, LES P = 0.84, STS P = 0.34). By using the area under the receiver operating characteristic curve (AUC), ESII better predicted 30‐day mortality, albeit poorly, compared to LES and STS (AUC = 0.68, 0.65, and 0.60, respectively). In the TF cohort, ESII was better in predicting 30‐day mortality compared to LES and STS (AUC = 0.74, 0.61, 0.60, respectively).

Conclusions

Although the ESII demonstrated better predictive performance especially in the TF cohort, ESII is still inadequate in predicting mortality after TAVI as are LES and STS. © 2013 Wiley Periodicals, Inc.
Candidates for transcatheter aortic valve replacement
Authors: Babcock Michael J. , Lavine Steven , Strom Joel A. , Bass Theodore A. , Guzman Luis A.
Published: October 2012

Objectives

To determine an estimate patient volume with severe AS meeting PARTNER‐B criteria, with the objective of providing insights into the annual volume needed to sustain a TAVR program.

Background

While the prevalence of AS is well documented, potential TAVR candidates remains less established. A better understanding of this population is critical for the development of TAVR programs. Though no clear volume has been determined, societies suggest a minimum of 20–24 annual cases to establish a TAVR program.

Methods

A total of 21,652 patients were screened from a single center echocardiography registry over a 3‐year period. From them, 833 patients with AS were identified representing our study population. Severity was stratified by echocardiographic criteria. Those identified to have moderate‐to‐severe and severe AS were further investigated to determine clinical status and surgical candidacy. Nonsurgical candidates were cross referenced with the PARTNER‐B exclusion criteria to determine eligibility for TAVR.

Results

Symptomatic AS was present in 133 patients (16%). Fifty (38%) were considered nonsurgical candidates. Nonsurgical patients had higher STS score (11.1 ± 10.8 vs. 4.0 ± 3.3, P < 0.001). After applying PARTNERS‐B exclusion criteria, only 18 patients (14%) were considered TAVR candidates. These findings indicate that to meet the recommended annual volume of 20–24 TAVR cases, a minimum of 150–170 symptomatic severe AS patients are required.

Conclusion

In real world clinical practice, the prevalence of AS meeting PARTNERS‐B criteria for TAVR can be low. These findings suggest that either high volume valvular centers or regional referral centers will need to be considered as part of the strategy to incorporate this new technology into clinical practice. © 2012 Wiley Periodicals, Inc.
Alkylaminosilane‐Assisted Simultaneous Etching and Growth Route to Synthesise Metal Nanoparticles Encapsulated by Silica Nanorattles
Authors: Wu Xiaoli , Tan Longfei , Chen Dong , He Xiaolong , Liu Huiyu , Meng Xianwei , Tang Fangqiong
Published: October 2012

An efficient and facile method to synthesise silica nanorattles with multiple noble metal (Au and Pd) cores by a simultaneous etching and growth route has been developed. In this strategy, a dual‐functional alkylaminosilane was adopted to form the middle layer of solid organic–inorganic hybrid solid‐silica spheres (HSSSs), which enabled the selective etching of the middle hybrid layer of the HSSSs and the in situ growth of metal nanoparticles (NPs) inside the cavity in a one‐step hydrothermal reaction. By adjusting the pH values of the reaction system, the metal NPs could be grown exclusively inside the silica nanorattles, resulting in a high atomic utilisation of the noble metals. The size and number of Au cores were tunable by manipulating the initial concentration of HAuCl4. The prepared silica nanorattles with Au cores were successfully applied to the catalytic reduction of 4‐nitrophenol and showed high catalytic activity and cycle stability. Catalysts with multiple gold cores exhibited superior catalytic activity to those with a single gold core, probably because they possess smaller Au cores with greater surface area.
The Role of Pd2+/Pd0 in Hydrogenation by [Pd(2‐pymo)2]n: An X‐ray Absorption and IR Spectroscopic Study
Authors: Schuster Sabine , Klemm Elias , Bauer Matthias
Published: October 2012

The metal–organic framework (MOF) [Pd(2‐pymo)2]n (2‐pymo=2‐pyrimidinolate) was used as catalyst in the hydrogenation of 1‐octene. During catalytic hydrogenation, the changes at the metal nodes and linkers of the MOF were investigated by in situ X‐ray absorption spectroscopy (XAS) and IR spectroscopy. With the help of extended X‐ray absorption fine structure and X‐ray absorption near edge structure data, Quick‐XAS, and IR spectroscopy, detailed insights into the catalytic relevance of Pd2+/Pd0 in the hydrogenation of 1‐octene could be achieved. Shortly after exposure of the catalyst to H2 and simultaneously with the hydrogenation of 1‐octene, the aromatic rings of the linker molecules are hydrogenated rapidly. Up to this point, the MOF structure remained intact. After completion of linker hydrogenation, the linkers were also protonated. When half of the linker molecules were protonated, the onset of reduction of the Pd2+ centers to Pd0 was observed and the hydrogenation activity decreased, followed by fast reduction of the palladium centers and collapse of the MOF structure. Major fractions of Pd0 are only observed when the hydrogenation of 1‐octene is almost finished. Consequently, the Pd2+ nodes of the MOF [Pd(2‐pymo)2]n are identified as active centers in the hydrogenation of 1‐octene.
Nanosheet‐Enhanced Asymmetric Induction of Chiral α‐Amino Acids in Catalytic Aldol Reaction
Authors: Zhao Li‐Wei , Shi Hui‐Min , Wang Jiu‐Zhao , He Jing
Published: October 2012

An efficient ligand design strategy towards boosting asymmetric induction was proposed, which simply employed inorganic nanosheets to modify α‐amino acids and has been demonstrated to be effective in vanadium‐catalyzed epoxidation of allylic alcohols. Here, the strategy was first extended to zinc‐catalyzed asymmetric aldol reaction, a versatile bottom‐up route to make complex functional compounds. Zinc, the second‐most abundant transition metal in humans, is an environment‐friendly catalytic center. The strategy was then further proved valid for organocatalyzed metal‐free asymmetric catalysis, that is, α‐amino acid catalyzed asymmetric aldol reaction. Visible improvement of enantioselectivity was experimentally achieved irrespective of whether the nanosheet‐attached α‐amino acids were applied as chiral ligands together with catalytic ZnII centers or as chiral catalysts alone. The layered double hydroxide nanosheet was clearly found by theoretical calculations to boost ee through both steric and H‐bonding effects; this resembles the role of a huge and rigid substituent.
Distinct expression patterns of Sulf1 and Hs6st1 spatially regulate heparan sulfate sulfation during prostate development
Authors: Buresh‐Stiemke Rita A. , Malinowski Rita L. , Keil Kimberly P. , Vezina Chad M. , Oosterhof Arie , Van Kuppevelt Toin H. , Marker Paul C.
Published: October 2012

Background: Prostate morphogenesis initiates in the urogenital sinus (UGS) with epithelial bud development. Sulfatase‐1 (SULF1) inhibits bud development by reducing extracellular heparan sulfate (HS) 6‐O sulfation and impairing FGF10 signaling by means of the ERK1/2 mitogen activated kinases. Results: We characterized the expression patterns of HS 6‐O sulfation modifying enzymes in the developing prostate by in situ hybridization and showed that Sulf1 and Hs6st1 had overlapping but distinct expression domains. Notably, Hs6st1 was present while Sulf1 was excluded from the tips of elongating epithelial buds. This predicted relatively high HS 6‐O sulfation at the tips of elongating epithelial buds that was confirmed by immunohistochemistry. The pattern of Sulf1 expression in the peri‐mesenchymal epithelium matched predicted locations of bone morphogenetic protein (BMP) signaling. Exogenous BMP4 and BMP7 induced Sulf1 expression in the UGS, decreased epithelial HS 6‐O sulfation, and reduced ERK1/2 activation in response to FGF10. Conclusions: These data suggest that BMPs limit FGF10 action in the developing prostate at least in part by inducing Sulf1. Developmental Dynamics, 2012. © 2012 Wiley Periodicals, Inc.
How to evolve new vertebrate sex determining genes
Authors: Graves Jennifer A. Marshall
Published: October 2012

Sex determination in vertebrates is accomplished by gonad differentiation in the embryo, which unleashes a cascade of hormones that control sexual phenotype. The pathway by which gonad (testis or ovary) is differentiated is highly conserved in all vertebrates, but the trigger (genetic or environmental) that initiates the whole process may be quite different between lineages. Among species with genetic sex determination, the trigger gene, and its mode of action as a male‐ or female‐dominant, or a dosage sensitive, is known in only a few species. Patterns are starting to emerge that hint at ways in which an autosomal gene may acquire ways of regulating genes at the head of the gonad differentiating pathway, usurp the sex determining function and define new sex chromosomes. The raw material for new sex‐determining genes may be genes in the sex differentiating pathway, related genes, or even genes with no known role in sex. The changes that make these genes sex determining can be as simple as a change in the timing or tissue of expression. Intriguingly, certain genes (such as DMRT1 and SOX3) seem to have been independently pressed into service in different ways in distantly related lineages. Developmental Dynamics 242:354–359, 2013. © 2012 Wiley Periodicals, Inc.
Spatio‐temporal expression of HOX genes in human hindgut development
Authors: Illig Romana , Fritsch Helga , Schwarzer Christoph
Published: October 2012

Background:
Hox genes belong to a highly conserved subgroup of the homeobox gene superfamily. Studies of animal models have emphasized their role in defining the body plan by their coordinated expression along the body axis during ontogeny. Although an important role of HOX genes in human development is assumed, little is known about their expression during human ontogenesis. Therefore, we investigated the expression of the nine most posterior members of the HOXA, HOXB, HOXC, and HOXD clusters in embryonic hindgut between weeks 6 to 12 and in adult rectal tissue. Results: Applying in situ hybridization and immunohistochemistry, we observed expression of HOXA11, HOXA13, HOXD12, and HOXD13 in developmental week 6. However, expression of HOXD12 faded during weeks 7 and 8, and then became increasingly re‐expressed during week 9 in humans. With the exception of HOXD13, all expressed HOX genes dropped below detection limits in week 11. Adult rectal tissue displayed distinct HOXA11, HOXA13, HOXD12, and HOXD13 expression patterns within the rectal layers. Conclusions: Our data suggest a strict spatio‐temporal regulation of HOX gene expression during human development, supporting the idea of their role as key regulators. Nonetheless, the expression pattern of distinct HOX genes differs markedly from animal models. Developmental Dynamics 242:53–66, 2013. © 2012 Wiley Periodicals, Inc.