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Functionalization by amine groups has been recognized as an effective route to promote the gas capture and separation performance of MOF materials; however, it remains elusive to date what is the optimal number of functional amine groups and which specific MOFs are suitable to be functionalized. To answer these questions, systemic investigations on the interactions between gas molecules and NH2-functionalized MOFs are necessary. Here a microporous Zn-F-triazolate framework which can be easily decorated by different -NH2 groups is selected (Zn-F-TRZ, Zn-F-ATRZ, and Zn-F-DATRZ; TRZ = 1,2,4-triazole, ATRZ = 3-amino-1,2,4-triazole, DATRZ = 3,5-diamino-1,2,4-triazole) to discuss the effect of amine groups on CO2 and C1/C2 hydrocarbon capture and separation. When the pressure is lower than about 0.15 atm, the CO2 uptakes increase directly with the number of anime groups (Zn-F-TRZ < Zn-F-ATRZ < Zn-F-DATRZ). However, at 1 atm, the decoration of one amine group effectively improves the CO2 adsorption of the Zn-F-triazolate framework, and the addition of a second amine group clearly decreases the CO2 uptakes. A similar uptake trend has been observed for C1/C2 hydrocarbons except for C2H2, which decrease dramatically with the number of amine groups. These results show that the combination of amine functional groups and appropriate pore size is responsible for the low-pressure binding and uptake of CO2 and C1/C2 hydrocarbon molecules in Zn-F-triazolate MOFs. Furthermore, thanks to the functionalization by amine groups, these Zn-F-triazolate frameworks all show excellent gas separation performance. Especially, the initial C2H2/CH4 selectivity (107.0) for Zn-F-ATRZ and initial CO2/CH4 (115.7), C2H4/CH4 (78.9), and CO2/C2H2 (5.9) selectivities for Zn-F-DATRZ at room temperature all surpass those of most of the MOFs reported up to now. [ABSTRACT FROM AUTHOR]

The effects of solvent polarity on the geometry and static first hyperpolarizability of one- and two-dimensional charge transfer molecules based on para-nitroaniline (PNA) and 1,3-diamino-4,6-dinitrobenzene (DADB) were studied using a polarizable continuum model (PCM) at the B3LYP/6-31+G(d,p) level of theory. The inclusion of solvent does not change the geometry significantly, but produces a change in the calculated results of the electronic structures and nonlinear optical properties. It is found that solvent polarity has an important influence on the first hyperpolarizability, whereas its influence is negligible on the nonlinearity anisotropy parameter both for PNA and DADB, due to the fact that the off-diagonal component and the diagonal component of the first hyperpolarizability possess similar solvent effect characteristics. [ABSTRACT FROM AUTHOR]

Isopropanol dehydrogenase (IPADH) is one of the most attractive options for nicotinamide cofactor regeneration due to its low cost and simple downstream processing. However, poor thermostability and strict cofactor dependency hinder its practical application for bioconversions. In this study, we simultaneously improved the thermostability (433-fold) and catalytic activity (3.3-fold) of IPADH from Brucella suis via a flexible segment engineering strategy. Meanwhile, the cofactor preference of IPADH was successfully switched from NAD(H) to NADP(H) by 1.23 × 106-fold. When these variants were employed in three typical bioredox reactions to drive the synthesis of important chiral pharmaceutical building blocks, they outperformed the commonly used cofactor regeneration systems (glucose dehydrogenase [GDH], formate dehydrogenase [FDH], and lactate dehydrogenase [LDH]) with respect to efficiency of cofactor regeneration. Overall, our study provides two promising IPADH variants with complementary cofactor specificities that have great potential for wide applications. [ABSTRACT FROM AUTHOR]

Thermal transport in silicon nanowires (SiNWs) has recently attracted considerable attention due to their potential applications in energy harvesting and generation and thermal management. The adjustment of the thermal conductivity of SiNWs through surface effects is a topic worthy of focus. In this paper, we briefly review the recent progress made in this field through theoretical calculations and experiments. We come to the conclusion that surface engineering methods are feasible and effective methods for adjusting nanoscale thermal transport and may foster further advancements in this field. [ABSTRACT FROM AUTHOR]

We report the design of a novel multiband metamaterial bandpass filter (BPF) in the terahertz (THz)-wave region. The designed BPF is composed of a metal–dielectric–metal sandwiched structure with three nested rings on the top surface and a cross structure on the bottom surface. Full-wave simulation results show that the designed BPF has three transmission peaks at frequencies of 0.42, 1.27, and 1.86 THz with transmission rates of −0.87, −1.85, and −1.83 dB, respectively. Multi-reflection interference theory is introduced to explain the transmission mechanism of the designed triple-band BPF. The theoretical transmission spectrum is in good agreement with the full-wave simulated results. The designed BPF can maintain a stable performance as the incident angle varies from 0° to 30° for both transverse electric and transverse magnetic polarizations of the incident wave. The designed BPF can be potentially used in THz devices due to its multiband transmissions, polarization insensitivity, and stable wide-angle response in the THz region. [ABSTRACT FROM AUTHOR]

Introduction: The long non-coding RNAs (lncRNAs) urothelial cancer associated 1 (UCA1) and metastasis associated lung adenocarcinoma transcript 1 (MALAT1) are known to impact cancer cell regulation. The aim of the present study was to determine the relationship between the expression of these lncRNAs in esophageal squamous cell carcinoma (ESCC) tissues and disease prognosis.Material and Methods: The expression of UCA1 and MALAT1 lncRNAs was assessed in ESCC and adjacent carcinoma tissues (5 cm away from the tumor) and evaluated in relation to overall survival (OS) and disease-free survival (DFS) of patients. This prospective study included 100 ESCC patients who were admitted to the First Hospital of Yulin City between January 2007 and January 2014.Results: The expression levels of UCA1 and MALAT1 lncRNAs in ESCC tissues were significantly higher than those in adjacent carcinoma tissues, and there were statistically significant differences in TNM staging between the patients with high lncRNA expression and low lncRNA expression. The OS and DFS of patients with high UCA1 and MALAT1 lncRNA expression levels were significantly shorter than those with low expression levels. Furthermore, the OS and DFS of ESCC patients appeared to be correlated with TNM staging.Conclusions: These results imply that the up-regulation of UCA1 and MALAT1 lncRNAs in ESCC tissues can impact the degree of tumor progression and is predictive of postoperative survival. Therefore, the expression levels of these lncRNAs can be used as measurement indexes to determine the prognosis of ESCC patients. [ABSTRACT FROM AUTHOR]

Silicene, a silicon analogue of graphene, has attracted increasing research attention in recent years because of its unique electrical and thermal conductivities. In this study, phonon thermal conductivity and its isotopic doping effect in silicene nanoribbons (SNRs) are investigated by using molecular dynamics simulations. The calculated thermal conductivities are approximately 32 W/mK and 35 W/mK for armchair-edged SNRs and zigzag-edged SNRs, respectively, which show anisotropic behaviors. Isotope doping induces mass disorder in the lattice, which results in increased phonon scattering, thus reducing the thermal conductivity. The phonon thermal conductivity of isotopic doped SNR is dependent on the concentration and arrangement pattern of dopants. A maximum reduction of about 15% is obtained at 50% randomly isotopic doping with30Si. In addition, ordered doping (i.e., isotope superlattice) leads to a much larger reduction in thermal conductivity than random doping for the same doping concentration. Particularly, the periodicity of the doping superlattice structure has a significant influence on the thermal conductivity of SNR. Phonon spectrum analysis is also used to qualitatively explain the mechanism of thermal conductivity change induced by isotopic doping. This study highlights the importance of isotopic doping in tuning the thermal properties of silicene, thus guiding defect engineering of the thermal properties of two-dimensional silicon materials. [ABSTRACT FROM AUTHOR]

Drug-loaded hydrophilic polymeric composite (HPC) is one of the most promising biomaterials for resolving the long-standing challenge of the development of oral solid formulations for insoluble drugs. With polyvinylpyrrolidone K10 (PVP) as polymeric carrier and sodium dodecyl sulfonate (SDS) as a surface active agent, a new type of HPC was fabricated for enhancing the dissolution of quercetin using an electrospraying process. A solvent mixture consisting of acetic acid, acetone and ethanol were exploited to prepare the codissolving solution of quercetin, PVP, and SDS for creating HPC. Both the sprayed nanoparticles and casting film fabricated using a thermal solvent evaporation process were amorphous composites, as demonstrated by the XRD results. ATR-FTIR spectra verified that the drug and the pharmaceutical carriers had good compatibility. In vitro dissolution experiments showed that the sprayed HPC could provide an over ten-fold faster dissolution rate than the casting film. Electrospraying is a facile method for developing new kinds of HPCs for insoluble drugs. [ABSTRACT FROM AUTHOR]

Phase gradient metasurfaces (PGMS) offer a fascinating ability to control the amplitude and phase of the electromagnetic (EM) waves on a subwavelength scale, resulting in new applications of designing novel microwave devices with improved performances. In this paper, a reflective symmetrical element, consisting of orthogonally I-shaped structures, has been demonstrated with an approximately parallel phase response from 15 GHz to 22 GHz, which results in an interesting wideband property. For practical design, a planar antenna is implemented by a well-optimized focusing metasurface and excited by a self-designed Vivaldi antenna at the focus. Numerical and experimental results coincide well. The planar antenna has a series of merits such as a wide 3-dB gain bandwidth of 15–22 GHz, an average gain enhancement of 16 dB, a comparable aperture efficiency of better than 45% at 18 GHz, and also a simple fabrication process. The proposed reflective metasurface opens up a new avenue to design wideband microwave devices. [ABSTRACT FROM AUTHOR]

We propose an anisotropic planar transmitting metasurface, which has the ability to manipulate orthogonally-polarized electromagnetic waves in the reflection and refraction modes respectively. The metasurface is composed of four layered rectangular patches spaced by three layered dielectric isolators each with a thickness of 0.15λ0 at 15 GHz. By tailoring the sizes of the patches, the metasurface functions as a band-stop filter for the y-polarzied wave and a band-pass filter for the x-polarized wave operating from 14 GHz to 16 GHz. Moreover the phases of the transmitting x-polarized wave can be modulated at about 15 GHz, which contributes to beam steering according to the general refraction law. Experimental results are in good accordance with the simulated ones, in which the reflection efficiency is almost 100% while the transmission efficiency of the x-polarized wave reaches 80% at 15 GHz. Besides, the transmitted x-polarized wave is effectively manipulated from 14 GHz to 16 GHz. [ABSTRACT FROM AUTHOR]

A new method to design an ultra-thin high-gain circularly-polarized antenna system with high efficiency is proposed based on the geometrical phase gradient metasurface (GPGM). With an accuracy control of the transmission phase and also the high transmission amplitude, the GPGM is capable of manipulating an electromagnetic wave arbitrarily. A focusing transmission lens working at Ku band is well optimized with the F/D of 0.32. A good focusing effect is demonstrated clearly by theoretical calculation and electromagnetic simulation. For further application, an ultra-thin single-layer transmissive lens antenna based on the proposed focusing metasurface operating at 13 GHz is implemented and launched by an original patch antenna from the perspective of high integration, simple structure, and low cost. Numerical and experimental results coincide well, indicating the advantages of the antenna system, such as a high gain of 17.6 dB, the axis ratio better than 2 dB, a high aperture efficiency of 41%, and also a simple fabrication process based on the convenient print circuit board technology. The good performance of the proposed antenna indicates promising applications in portable communication systems. [ABSTRACT FROM AUTHOR]

Cyclic stretch is an important inducer of vascular smooth muscle cell (VSMC) proliferation, which is crucial in vascular remodeling during hypertension. However, the molecular mechanism remains unclear. We studied the effects of emerin and lamin A/C, two important nuclear envelope proteins, on VSMC proliferation in hypertension and the underlying mechano-mechanisms. In common carotid artery of hypertensive rats in vivo and in cultured cells subjected to high (15%) cyclic stretch in vitro, VSMC proliferation was increased significantly, and the expression of emerin and lamin A/C was repressed compared with normotensive or normal (5%) cyclic stretch controls. Using targeted siRNA to mimic the repressed expression of emerin or lamin A/C induced by 15% stretch, we found that VSMC proliferation was enhanced under static and 5%-stretch conditions. Overexpression of emerin or lamin A/C reversed VSMC proliferation induced by 15% stretch. Hence, emerin and lamin A/C play critical roles in suppressing VSMC hyperproliferation induced by hyperstretch. ChIP-on-chip and MOTIF analyses showed that the DNAs binding with emerin contain three transcription factor motifs: CCNGGA, CCMGCC, and ABTTCCG; DNAs binding with lamin A/C contain the motifs CVGGAA, GCCGCYGC, and DAAGAAA. Protein/DNA array proved that altered emerin or lamin A/C expression modulated the activation of various transcription factors. Furthermore, accelerating local expression of emerin or lamin A/C reversed cell proliferation in the carotid artery of hypertensive rats in vivo. Our findings establish the pathogenetic role of emerin and lamin A/C repression in stretch-induced VSMC proliferation and suggest mechanobiological mechanism underlying this process that involves the sequence-specific binding of emerin and lamin A/C to specific transcription factor motifs. [ABSTRACT FROM AUTHOR]

Micro metal droplet is the basic building block of three-dimensional metal parts fabricated by micro droplet deposition manufacturing (MDDM) technique. In this paper, the effect of wetting behavior between liquid metal and spray nozzle on the generation of micro aluminum droplets produced by pneumatic drop-on-demand (DOD) technique was investigated by simulation and experiment. A finite element model of liquid-gas flow was established based on the improved level set method (LSM). Then the generation of micro liquid aluminum droplets under different wetting conditions was simulated. A series of spraying experiments were also performed on micro droplet deposition experiment platform. The results show that the generation and flight of micro aluminum droplets are influenced by wetting condition between liquid metal and the nozzle surface significantly. Additionally, the effect of wetting behavior on the droplet size was analyzed to achieve the smallest building block. It was found that the droplet radius decreased with the increase of contact angle exponentially, which agreed with the numerical calculation and experiment results. On this basis, a wettability criterion was proposed for selecting nozzle materials. These works would be helpful for the processing optimization and equipment improvement of MDDM technique. [ABSTRACT FROM AUTHOR]

Glioma, as the most common and lethal intracranial tumor, is a serious disease that causes many deaths every year. Good comprehension of the mechanism underlying this disease is very helpful to design effective treatments. However, up to now, the knowledge of this disease is still limited. It is an important step to understand the mechanism underlying this disease by uncovering its related genes. In this study, a graphic method was proposed to identify novel glioma related genes based on known glioma related genes. A weighted graph was constructed according to the protein-protein interaction information retrieved from STRING and the well-known shortest path algorithm was employed to discover novel genes. The following analysis suggests that some of them are related to the biological process of glioma, proving that our method was effective in identifying novel glioma related genes. We hope that the proposed method would be applied to study other diseases and provide useful information to medical workers, thereby designing effective treatments of different diseases. [ABSTRACT FROM AUTHOR]

Background: Knee osteoarthritis (OA) is a major cause of disability as well as a burden on healthcare resources. Tai chi has been proposed as an alternative and complementary treatment for the management of knee osteoarthritis, but there appears to be no consensus on its usefulness. This study aims to develop an innovative tai chi rehabilitation program (ITCRP) for patients with knee OA, and to investigate the effect of ITCRP intervention on a range of outcomes including pain, function, balance, neuromuscular response, and biomechanics in knee OA. Methods/Design: We will conduct a prospective, single-blind, randomized controlled trial of 140 individuals with symptomatic knee OA. Patients will be randomly assigned into either an ITCRP group or a control group. The ITCRP group will participate in tai chi two or three times a week for 6 months. The control group will receive health education. After the 6-month intervention period, there will be a 6-month follow-up period with no active intervention in either group. The primary and secondary outcomes will be assessed at baseline, 6 months, and 12 months. Primary outcome measures will be a visual analog scale for pain, the Western Ontario and McMaster Universities Osteoarthritis Index,and the Lequesne Knee Score. The secondary outcome measures will include the Berg balance scale, knee and ankle proprioception, neuromuscular response, and 3D functional biomechanics. Furthermore, adverse events will be recorded and analyzed. If any participants withdraw from the trial, intention-to-treat analysiswill be performed. Discussion: Important features of this trial include the randomization procedures, large sample size, and a standardized protocol for ITCRP for knee OA. This study aims to determine the feasibility of ITCRP for knee OA and provide data on the effects of ITCRP. Hence, our results will be useful for patients with knee OA as well as for medical staff and healthcare decision makers. [ABSTRACT FROM AUTHOR]

With a large number of disordered proteins and their important functions discovered, it is highly desired to develop effective methods to computationally predict protein disordered regions. In this study, based on Random Forest (RF), Maximum Relevancy Minimum Redundancy (mRMR), and Incremental Feature Selection (IFS), we developed a new method to predict disordered regions in proteins. The mRMR criterion was used to rank the importance of all candidate features. Finally, top 128 features were selected from the ranked feature list to build the optimal model, including 92 Position Specific Scoring Matrix (PSSM) conservation score features and 36 secondary structure features. As a result, Matthews correlation coefficient (MCC) of 0.3895 was achieved on the training set by 10-fold cross-validation. On the basis of predicting results for each query sequence by using the method, we used the scanning and modification strategy to improve the performance. The accuracy (ACC) and MCC were increased by 4% and almost 0.2%, respectively, compared with other three popular predictors: DISOPRED, DISOclust, and OnD-CRF. The selected features may shed some light on the understanding of the formation mechanism of disordered structures, providing guidelines for experimental validation. [ABSTRACT FROM AUTHOR]

Lung cancer is one of the leading causes of cancer mortality worldwide. The main types of lung cancer are small cell lung cancer (SCLC) and nonsmall cell lung cancer (NSCLC). In this work, a computational method was proposed for identifying lung-cancerrelated genes with a shortest path approach in a protein-protein interaction (PPI) network. Based on the PPI data from STRING, a weighted PPI network was constructed. 54 NSCLC- and 84 SCLC-related genes were retrieved from associated KEGG pathways. Then the shortest paths between each pair of these 54 NSCLC genes and 84 SCLC genes were obtained with Dijkstra's algorithm. Finally, all the genes on the shortest paths were extracted, and 25 and 38 shortest genes with a permutation P value less than 0.05 for NSCLC and SCLC were selected for further analysis. Some of the shortest path genes have been reported to be related to lung cancer. Intriguingly, the candidate genes we identified from the PPI network contained more cancer genes than those identified from the gene expression profiles. Furthermore, these genes possessed more functional similarity with the known cancer genes than those identified from the gene expression profiles. This study proved the efficiency of the proposed method and showed promising results. [ABSTRACT FROM AUTHOR]

Most drugs have beneficial as well as adverse effects and exert their biological functions by adjusting and altering the functions of their target proteins. Thus, knowledge of drugs target proteins is essential for the improvement of therapeutic effects and mitigation of undesirable side effects. In the study, we proposed a novel prediction method based on drug/compound ontology information extracted from ChEBI to identify drugs target groups from which the kind of functions of a drug may be deduced. By collecting data in KEGG, a benchmark dataset consisting of 876 drugs, categorized into four target groups, was constructed. To evaluate the method more thoroughly, the benchmark dataset was divided into a training dataset and an independent test dataset. It is observed by jackknife test that the overall prediction accuracy on the training dataset was 83.12%, while it was 87.50% on the test dataset--the predictor exhibited an excellent generalization. The good performance of the method indicates that the ontology information of the drugs contains rich information about their target groups, and the study may become an inspiration to solve the problems of this sort and bridge the gap between ChEBI ontology and drugs target groups. [ABSTRACT FROM AUTHOR]

Protein concentrations depend not only on the mRNA level, but also on the translation rate and the degradation rate. Prediction of mRNA's translation rate would provide valuable information for in-depth understanding of the translation mechanism and dynamic proteome. In this study, we developed a new computational model to predict the translation rate, featured by (1) integrating various sequence-derived and functional features, (2) applying the maximum relevance & minimum redundancy method and incremental feature selection to select features to optimize the prediction model, and (3) being able to predict the translation rate of RNA into high or low translation rate category. The prediction accuracies under rich and starvation condition were 68.8% and 70.0%, respectively, evaluated by jackknife cross-validation. It was found that the following features were correlated with translation rate: codon usage frequency, some gene ontology enrichment scores, number of RNA binding proteins known to bind its mRNA product, coding sequence length, protein abundance and 5'UTR free energy. These findings might provide useful information for understanding the mechanisms of translation and dynamic proteome. Our translation rate prediction model might become a high throughput tool for annotating the translation rate of mRNAs in large-scale. [ABSTRACT FROM AUTHOR]

Background: Metabolic pathway is a highly regulated network consisting of many metabolic reactions involving substrates, enzymes, and products, where substrates can be transformed into products with particular catalytic enzymes. Since experimental determination of the network of substrate-enzyme-product triad (whether the substrate can be transformed into the product with a given enzyme) is both time-consuming and expensive, it would be very useful to develop a computational approach for predicting the network of substrate-enzyme-product triads. Results: A mathematical model for predicting the network of substrate-enzyme-product triads was developed. Meanwhile, a benchmark dataset was constructed that contains 744,192 substrate-enzyme-product triads, of which 14,592 are networking triads, and 729,600 are non-networking triads; i.e., the number of the negative triads was about 50 times the number of the positive triads. The molecular graph was introduced to calculate the similarity between the substrate compounds and between the product compounds, while the functional domain composition was introduced to calculate the similarity between enzyme molecules. The nearest neighbour algorithm was utilized as a prediction engine, in which a novel metric was introduced to measure the "nearness" between triads. To train and test the prediction engine, one tenth of the positive triads and one tenth of the negative triads were randomly picked from the benchmark dataset as the testing samples, while the remaining were used to train the prediction model. It was observed that the overall success rate in predicting the network for the testing samples was 98.71%, with 95.41% success rate for the 1,460 testing networking triads and 98.77% for the 72,960 testing non-networking triads. Conclusions: It is quite promising and encouraged to use the molecular graph to calculate the similarity between compounds and use the functional domain composition to calculate the similarity between enzymes for studying the substrate-enzyme-product network system. The software is available upon request. [ABSTRACT FROM AUTHOR]

The 4-bp deletion (-CTTT) at codon 41/42 (CD41/42) of the human β-globin gene represents one of the most common β-thalassemia mutations in East Asia and Southeast Asia, which is historically afflicted with endemic malaria, thus hypothetically evolving under natural selection by malaria infection. To understand the evolutionary process of generating the βCD41/42 allele and its maintenance, including the effect of natural selection on the pattern of linkage disequilibrium (LD), we sequenced a 15.933-kb region spanning 20.693 kb of the β-globin cluster surrounding the 4-bp deletion using a sample from a Chinese population consisting of 24 normal individuals and 16 heterozygotes for the deletion. Forty-nine polymorphic sites were found. Analysis of the data, using a variety of methods including formal population genetics analysis and visual approaches, suggests that the spread of the CD41/42 (-CTTT) deletion is most likely mediated by interallelic gene conversion, although independent deletions in different lineages are also possible. The neutrality test resulted in a significant positive Tajima’s D for the β-globin locus, which is consistent with the existence of balancing selection. This suggests that the 4-bp deletion that occurred at this locus may be an event that is subject to natural selection, due to malaria, which leads to the heterozygote advantage, spread widely with further help by conversion and migration. The evolutionary process of this mutant through gene conversion that could conceivably take place between the 4-bp deletion and the normal sequence in the respective region is discussed in detail. [ABSTRACT FROM AUTHOR]

We report a polarization beam splitter based on phase gradient metasurface for microwave frequency region. The metasurface is constructed by anisotropic cells with independent phase response for differently-polarized waves. Through putting different gradient phases for orthogonally-polarized waves on a focusing metasurface, the anisotropic sample has the ability to enhance gain and split orthogonally-polarized waves. The simulation results indicate that the incident spherical waves are converted into plane waves and split into an x-polarized wave with a refraction angle of −24° and a y-polarized wave with a refraction angle of 37.6° in the y direction. For verification, a metasurface sample with a size of 102.5 mm ×102.5 mm is fabricated and measured. The consistence between numerical and experimental results validates the improved gain of 10.5-dB against the feed source and the splitting effect. Moreover, the thickness of the proposed metasurface is 3 mm which is ultra-thin against the wavelength at 15 GHz. The proposed prescription opens a new route to the applications of anisotropic metasurface in microwave band. [ABSTRACT FROM AUTHOR]