Microwave-enhanced densification of sol-gel alumina films

Alumina films prepared by the sol-gel method were sintered at 1160 °C and 1200 °C using a 2.45 GHz microwave / conventional hybrid furnace in order to study the influence of microwave power on the sintering process and resultant samples. Experiments were designed to ensure that each series of samples underwent an identical thermal history in terms of temperature / time profiles. Sintering was carried out using three different heating approaches: pure conventional heating and hybrid heating with 600 W and 1000 W of microwave radiation, respectively. The results obtained showed that, compared with pure conventional heating, the presence of the microwave field led to higher sintered densities and crystallinity in the samples, indicating that the microwave field enhanced the sintering of the sol-gel alumina films and supporting the existence of the microwave effect

Evidence for the microwave effect during the annealing of zinc oxide

A microwave/conventional hybrid furnace has been used to anneal virtually fully dense zinc oxide ceramics under pure conventional and a microwave/conventional hybrid heating regime with a view to obtaining evidence for the ‘microwave effect’ during the resulting grain growth. In each case it was ensured that each sample within a series had an identical thermal history in terms of its temperature/time profile. The results showed that grain growth was enhanced during hybrid heating compared to pure conventional heating; the greatest enhancement, a factor of ~3 increase in average grain size, was observed in the range 1100-1150°C. The grain growth exponent decreased from 3 during conventional heating to 1.4 during hybrid heating in this temperature range, suggesting an acceleration of the diffusional processes involved. Temperature gradients within the samples were found to be too small to explain the results. This suggests that clear evidence has been found to support the existence of a genuine ‘microwave effect’

Evidence for the microwave effect during hybrid sintering

A microwave/conventional hybrid furnace has been used to sinter three ceramics with different microwave absorption characteristics under pure conventional and a range of microwave/ conventional hybrid heating regimes. The precursor powder particle size was also varied for each material. In each case it was ensured that every sample within a series had an identical thermal history in terms of its temperature/time profile. An increase in both the onset of densification and the final density achieved was observed with an increasing fraction of microwave energy used during sintering, the effect being greatest for the materials that absorbed microwaves most readily. Twenty-three percent greater densification was observed for submicron zinc oxide powder, the material with the largest microwave absorption capability, when sintered using hybrid heating involving 1 kW of microwave power compared with pure conventional power under otherwise identical conditions. For the ceramic with the lowest microwave absorption characteristic, alumina, the increase in densification was extremely small; partially stabilized zirconia, a moderate microwave absorber, was intermediate between the two. Temperature gradients within the samples, a potential cause of the effect, were assessed using two different approaches and found to be too small to explain the results. Hence, it is believed that clear evidence has been found to support the existence of a genuine ‘‘microwave effect.’

Micellization and Single-Particle Encapsulation with Dimethylammoniopropyl Sulfobetaines

Sulfobetaines (SBs) are a class of zwitterionic surfactants with a reputation for enhancing colloidal stability at high salt concentrations. Here, we present a systematic study on the self-assembly of SB amphiphiles (sultaines or hydroxysultaines) in aqueous solutions, as a function of chain length and composition, ionic strength, and in the presence of alkanethiol-coated Au nanoparticles (GNPs). The diameters of the micelles assembled from SB and amidosulfobetaine (ASB) generally increase monotonically with chain length, although ASB micelles are smaller relative to alkyl SB micelles with similarly sized tailgroups, and oleyl sulfobetaine (OSB) micelles are slightly larger. SB amphiphiles can stabilize alkanethiol-coated GNPs in physiologically relevant buffers at concentrations well below their CMC, with size increases corresponding to single-particle encapsulation. SB-encapsulated GNPs were prepared by three different methods with SB:GNP weight ratios of 10:1, followed by dispersion in water or 1 M NaCl. The low hydrodynamic size of the SB micelles and SB-coated NPs is within the range needed for efficient renal clearance

Potential of High Load Extension for Gasoline HCCI Engine Using Boosting and Exhaust Gas Recirculation

Homogeneous charge compression ignition (HCCI) still faces challenges in high load extension. In this paper, HCCI high load operation range was extended and combustion phasing was controlled by boosting combined with internal EGR and external EGR in a gasoline HCCI engine. Internal EGR was obtained by negative valve overlap (NVO) and used to achieve gasoline HCCI at ambient temperature without intake heating. Combustion phasing was optimized by adjusting the external EGR inducted into the intake system. The experimental results show that both boosting and EGR are effective means for HCCI high load extension but with limitations of peak pressure (<i>P</i>_max), maximum rate of pressure rise (<i>R</i>_max), combustion efficiency (η_c), and NO_<i>x</i> emissions. Under the acceptable <i>P</i>_max, <i>R</i>_max, η_c, and NO_<i>x</i> levels of a production gasoline engine, the achievable maximum IMEP is in the following order: external EGR, boosting, boosting combined with EGR. With increasing boost pressure, NO_<i>x</i> emissions are significantly reduced. But with acceptable <i>P</i>_max, heavy boosting leads to an ultralean mixture, followed by uncompleted combustion, which results in CO and HC emissions. At a fixed NVO, there is an appropriate range of the external EGR rate for stable HCCI combustion without knocking or misfire. Therefore, the optimized path was achieved using various internal EGR and external EGR combined to extend HCCI high load operation range. In addition, it can be found that boost pressure, percentage of CO₂ addition, and internal and external EGR rate have shown significant effects on combustion phasing of HCCI

Efficient continuous kinetic resolution of racemic 2-aminobutanol over immobilized penicillin G acylase

<p>In this paper, an efficient method was established for continuous kinetic resolution of racemic 2-aminobutanol by selective hydrolysis of N-phenylacetyl (±)-2-aminobutanol over immobilized penicillin G acylase (PGA) in a fixed-bed reactor. Several N-acylated derivatives of 2-aminobutanol were screened in batch experiments, and it was found that the hydrolysis of N-phenylacetyl (±)-2-aminobutanol proceeded smoothly in the presence of immobilized penicillin G acylase with satisfied enantioselectivity. Thus, the reaction parameters were optimized in a fixed-bed reactor. Under the optimized conditions, 39.3% conversion of N-phenylacetyl (±)-2-aminobutanol and 98.2% ee value of S-2-aminobutanol were obtained. This fixed-bed system was operated continuously for 40 h without significant decrease of enzyme activity. It has been demonstrated to be more efficient compared to the batch experiments.</p

Data_Sheet_1_Structure and assembly process of fungal communities in the Yangtze River Estuary.pdf

Marine fungi are essential for the ecological function of estuarine ecosystems. However, limited studies have reported on the structure and assembly pattern of the fungal communities in estuaries. The purpose of this study is to reveal the structure and the ecological process of the fungal community in the Yangtze River Estuary (YRE) by using the amplicon sequencing method. Phyla of Ascomycota, Basidiomycota, and Chytridiomycota were dominant in the seawater and sediment samples from YRE. The null model analysis, community-neutral community model (NCM), and phylogenetic normalized stochasticity ratio (pNST) showed that the stochastic process dominated the assembly of fungal communities in YRE. Drift and homogeneous dispersal were the predominant stochastic processes for the fungal community assembly in seawater and sediment samples, respectively. The co-occurrence network analysis showed that fungal communities were more complex and closely connected in the sediment than in the seawater samples. Phyla Ascomycota, Basidiomycota, and Mucoromycota were the potential keystone taxa in the network. These findings demonstrated the importance of stochastic processes for the fungal community assembly, thereby widening our knowledge of the community structure and dynamics of fungi for future study and utilization in the YRE ecosystem.</p

TEMs but not DKK1 could serve as complementary biomarkers for AFP in diagnosing AFP-negative hepatocellular carcinoma

<div><p>Background & aims</p><p>Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is prevalent worldwide. Despite its limitations, serum alpha-fetoprotein (AFP) remains the most widely-used biomarker for the diagnosis of HCC. This study aimed to assess whether measurement of peripheral plasma Dickkopf-1 (DKK1) and Tie2-expressing monocytes (TEMs) could overcome the limitations of AFP and improve the diagnostic accuracy of HCC.</p><p>Methods</p><p>Plasma DKK1 level and the percentage of TEMs in peripheral CD14+CD16+ monocytes from HCC patients (<i>n</i> = 82), HBV-related liver cirrhosis (LC) patients (<i>n</i> = 29), chronic hepatitis B (CHB) infected patients (<i>n</i> = 28) and healthy volunteers (<i>n</i> = 31) were analyzed by ELISA and flow cytometry. Receiver operating characteristic (ROC) curves were used to analyze a single biomarker, or a combination of two or three biomarkers. Univariate and multivariate analyses were performed to assess the significance of each marker in prediction of HCC and AFP-negative HCC from LC patients.</p><p>Results</p><p>The percentage of TEMs in peripheral CD14+CD16+ monocytes and plasma level of DKK1 in HCC group were significantly higher than those in LC, CHB and healthy control groups (all <i>P</i>-values <0.05). The percentage of TEMs alone was also significantly higher in AFP-negative HCC group than that in LC, CHB and healthy control groups (all <i>P</i>-values <0.05). Plasma DKK1 level alone could not distinguish between AFP-negative HCC and LC patients. ROC curves showed that the optimal diagnostic cutoff value was 550.93 ng/L for DKK1 and 4.95% for TEMs. There was no significant difference in AUC of DKK1, TEMs and AFP in HCC diagnosis between the four groups (all <i>P</i>>0.05). A combination of DKK1, TEMs and AFP measurements increased the AUC for HCC diagnosis as compared with either marker alone (0.833; 95%CI 0.768–0.886). The AUC for TEMs was 0.692 (95% CI 0.564–0.819) in differentiating AFP-negative HCC from LC, with a sensitivity of 80.0% and a specificity of 65.52%. Only TEMs prevailed as a significant predictor for AFP-negative HCC differentiating from LC patients in univariate and multivariate analyses (<i>P</i> = 0.016, <i>P</i> = 0.023).</p><p>Conclusions</p><p>TEMs and DKK1 may prove to be potential complementary biomarkers for AFP in the diagnosis of HCC. TEMs rather than DKK1 could serve as a complementary biomarker for AFP in the differential diagnosis of AFP-negative HCC versus LC patients.</p></div

Construction of PSLIN.

<p>A network in the left represents a global PIN. A eukaryotic cell in the center can be divided into 11 compartments, <i>Endoplasmic</i>, <i>Cytoskeleton</i>, <i>Golgi</i>, <i>Cytosol</i>, <i>Lysosome</i>(or <i>Vacuole</i>), <i>Mitochondrion</i>, <i>Endosome</i>, <i>Plasma</i>, <i>Nucleus</i>, <i>Peroxisome</i> and <i>Extracellular</i>, where <i>Lysosome</i> only exists in animal cells. For each compartment, a PSLIN of this compartment is constituted by the proteins localized in this compartment and their interactions. With the subcellular localization information of proteins, the PSLINs can be generated by mapping the global PIN to each compartment separately.</p

HybridDock: A Hybrid Protein–Ligand Docking Protocol Integrating Protein- and Ligand-Based Approaches

Structure-based molecular docking and ligand-based similarity search are two commonly used computational methods in computer-aided drug design. Structure-based docking tries to utilize the structural information on a drug target like protein, and ligand-based screening takes advantage of the information on known ligands for a target. Given their different advantages, it would be desirable to use both protein- and ligand-based approaches in drug discovery when information for both the protein and known ligands is available. Here, we have presented a general hybrid docking protocol, referred to as HybridDock, to utilize both the protein structures and known ligands by combining the molecular docking program MDock and the ligand-based similarity search method SHAFTS, and evaluated our hybrid docking protocol on the CSAR 2013 and 2014 exercises. The results showed that overall our hybrid docking protocol significantly improved the performance in both binding affinity and binding mode predictions, compared to the sole MDock program. The efficacy of the hybrid docking protocol was further confirmed using the combination of DOCK and SHAFTS, suggesting an alternative docking approach for modern drug design/discovery