Complicated Mixture Research Articles

Pyrolysis of lignocellulosic biomass: Molecular-level insights with online ultrahigh-resolution mass spectrometry

Pyrolysis is a feasible way to convert lignocellulosic biomass into renewable fuels and chemicals. Comprehensive elucidation of chemical compositions of both intermediates and final products of biomass pyrolysis at the molecular level is essential to understanding the reaction mechanism, which may help to improve this sustainable process. Because biomass pyrolysis product is such a complicated mixture containing almost various kinds of organic oxygenated compounds, molecular characterization is challenging even with state-of-the-art analytical techniques. Online ultrahigh-resolution mass spectrometry (UHRMS) coupled with soft atmospheric pressure ionization (API) offers new opportunities in this context. Herein, we outline the instrumental concept of API-UHRMS dedicated to process analysis and its contributions to the molecular-level understanding of biomass pyrolysis. Recent progress in the online mass spectrometric characterization of the evolved gaseous products from pyrolysis of both complex raw biomass and three major constituents (cellulose, hemicellulose, and lignin) was summarized. In addition, the potential challenges and future perspectives in the context of analytical pyrolysis and process analysis are also discussed.

Sustainable Valorization of E-Waste Plastic through Catalytic Pyrolysis Using CO2

A massive amount of waste of electrical and electronic equipment (E-waste) is being discarded as a solid waste. A valorization platform for the organic part in E-waste has not been fully matured, while metallic compounds have been properly recycled. In these respects, a reliable disposal platform for complex plastic compounds in E-waste is developed in this study. Using a pyrolysis platform, the complicated plastic mixture in E-waste was valorized into value-added products. To deliberate a more environmentally benign process, CO2 was used as a cofeedstock. As a model E-waste, LCD monitor waste (LMW) was tested. The exact types of plastics in LMW (polyacrylonitrile, polybutadiene, polystyrene, poly(methyl methacrylate), polyethylene terephthalate, and polycarbonate) and their mass fractions were determined. From pyrolysis of LMW, the heterogeneous mixture of liquid (toxic) hydrocarbons was generated. To selectively convert/detoxify hydrocarbon into syngas (H2/CO), catalytic pyrolysis was applied. A Ni catalyst led to chemical bond scissions, improving H2 formation. When CO2 was fed as a cofeedstock, volatile hydrocarbons were further turned into CO through chemical reactions between CO2 and hydrocarbons. This synergistic effect of CO2 and Ni catalyst improved syngas formation more than 15 times. CO2 also greatly extended the stability of a catalyst, effectively preventing coke formation.

Cooperative control of intralayer and interlayer space in MOFs enables selective capture of intermediate-sized molecules

Adsorptive separation of the smallest or largest molecules from a mixture can be realized by the sieving effect; however, it is still an arduous task to specifically discriminate between the intermediate-sized component from a complicated multicomponent mixture. Here, we report a strategy via cooperative control of intralayer and interlayer space for selective adsorption of ethane from methane and propane on a 2D-layered MOF termed Ni(4-DPDS)2CrO4. The intralayer channels work as main adsorption sites, while interlayer channels are designed to achieve optimal discrepancy of kinetic diffusion rates. The restricted diffusion of C3H8 in the interlayer channels results in a dramatic inversed, equilibrium-kinetic, combined selectivity for C2H6/C3H8. Mixture breakthrough experiments manifest an efficient capture of C2H6 owing to the equilibrium-kinetic synergetic effect. The mechanism for selective gas adsorption is well supported by kinetic results and crystallography studies, demonstrating that fabrication of MOFs with multiple distinct controllable micropores enables selective capture of intermediate-sized molecules.

Phylogeny and biogeography of the ancient spider family Filistatidae (Araneae) is consistent both with long-distance dispersal and vicariance following continental drift.

Filistatids, the crevice weavers, are an ancient family of cribellate spiders without extant close relatives. As one of the first lineages of araneomorph spiders, they present a complicated mixture of primitive and derived characters that make them a key taxon to elucidate the phylogeny of spiders, as well as the evolution of phenotypic characters in this group. Their moderate diversity (187 species in 19 genera) is distributed mainly in arid and semi-arid subtropical zones of all continents, except Antarctica. The objective of this paper is to generate a comprehensive phylogenetic hypothesis for this family to advance the understanding of its morphological evolution and biogeography, as well as lay the basis for a natural classification scheme. By studying the morphology using optical and electronic microscopy techniques, we produced a matrix of 302 morphological characters coded for a sample of 103 species of filistatids chosen to represent the phylogenetic diversity of the family. In addition, we included sequences of four molecular markers (COI, 16S, H3 and 28S; 3787 aligned positions) of 70 filistatid species. The analysis of the data (morphological, molecular, and combined) consistently indicates the separation of the Filistatidae into two subfamilies, Prithinae and Filistatinae, in addition to supporting several groups of genera: Filistata, Zaitunia and an undescribed genus from Madagascar; Sahastata and Kukulcania; all Prithinae except Filistatinella and Microfilistata; Antilloides and Filistatoides; a large Old World group including Pritha, Tricalamus, Afrofilistata, Labahitha, Yardiella, Wandella and putative new genera; and a South American group formed by Lihuelistata, Pikelinia and Misionella. Pholcoides is transferred to Filistatinae and Microfilistata is transferred to Prithinae, and each represents the sister group to the remaining genera of its own subfamily. Most genera are valid, although Pikelinia is paraphyletic with respect to Misionella, so we consider the two genera as synonyms and propose a few new generic combinations. Considering the new phylogenetic hypothesis, we discuss the evolution of some morphological character systems and the biogeography of the family. The ages of divergence between clades were estimated using a total-evidence tip-dating approach by including fossils of Filistatidae and early spider clades; this approach resulted in younger age estimates than those obtained with traditional node-dating. Filistatidae is an ancient family that started diversifying in the Mesozoic and most genera date to the Cretaceous. Clades displaying transcontinental distributions were most likely affected by continental drift, but at least one clade shows unequivocal signs of transoceanic long-distance dispersal.

Simultaneous analysis of amino acids based on discriminative 19F NMR spectroscopy

The simultaneous analysis of amino acids (AAs) is crucial for human health, diagnosis and treatment of disease, and nutritional quality evaluation in foodstuffs. Here, we establish an easy and rapid method for the simultaneous analysis of AAs using a single reagent 2-(trifluoromethyl)benzaldehyde (oTFMBA) based on spectral-separation-enabled 19F NMR spectroscopy. oTFMBA, a highly sensitive chemosensor, is capable of analyzing 19 proteinogenic AAs or non-amino acid amines (non-AAs) in a complex mixture by adjusting the pH in a toilless way. The 19F signals of oTFMBA-labeled AAs are distributed over a wide range of ∼ 0.7 ppm, demonstrating oTFMBA with higher resolution for simultaneous analysis of AAs compared to the o-phthaldialdehyde (OPA) method (<0.6 ppm). Additionally, 12 AAs were unambiguously identified in human urine, including Asp, Ser, Gly, Thr, Glu, Arg, Ala, Val, Ile, Tyr, His, and Phe. Furthermore, our method’s detection limit for AAs is 5.83 μM, illustrating sensitivity with an ∼100-fold improvement over the OPA method. This work represents an approach to the analysis of AAs or non-AAs in a complicated mixture (even biofluid) using a 19F NMR probe with high sensitivity, which is of great significance for the simultaneous analysis of multiple analytes.

Valorizing plastic toy wastes to flammable gases through CO2-mediated pyrolysis with a Co-based catalyst

Toys are discarded due to their short life cycle. Unfortunately, development of sustainable disposal platform for toy has not gained particular concern. To establish a reliable disposal platform, this study employed a pyrolysis platform to valorize plastics into value-added fuels. To confer more environmentally resilient process, CO2 was used as a feedstock to enhance the process efficiency from a perspective of the yield of flammable gases. To this end, waste toy brick (WTB) was used as a model compound. The exact types of plastics (polyacrylonitrile, polybutadiene, polystyrene, and polymethyl methacrylate) in WTB were experimentally determined. In pyrolysis of WTB, the complicated mixture of benzene derivatives was inevitably generated. To detoxify them by means of syngas (H2/CO) production, catalytic pyrolysis was performed. Co catalyst effectively induced chemical bond scissions, leading to substantially enhanced H2 formation. Also, the gas phase reactions (GPRs) between CO2 and volatile compounds over Co catalyst expedited the production rate of CO, and such CO enhancement effectively offered a chance to mitigate toxic chemical generations. The synergistic contribution of CO2 and Co catalyst enhanced syngas formation more than 25 times in reference to pyrolysis of WTB without Co catalyst. The GPRs also greatly prevented catalyst deactivation.

Dinucleating ligands based on functionalized oxalamides: Lability of Re(I) coordination with the phosphorus pendant arms

The reactions of ortho-(thio)phosphorylated anilines with oxalyl chloride smoothly afforded new ditopic pincer ligands with an oxalamide core and phosphorus(V) pendant arms. The thiophosphoryl-functionalized oxalamide readily underwent direct cyclometalation under the action of Re(CO)5Br in the presence of a base, furnishing the expected ditopic Re(I) pincer complex. At the same time, its phosphoryl-containing counterpart, owing to the labile coordination of the PO groups, afforded a complicated mixture of products, which finally resulted in two binuclear complexes with either coordinated or uncoordinated phosphoryl arms. The structures of all the isolated complexes were elucidated using NMR and IR spectroscopy as well as X-ray diffraction analysis, which provided some insight into the mechanism of their formation. The results of the preliminary evaluation of cytotoxic properties of some of the Re(I) complexes are presented.

A review on fly ash cenosphere as a solid waste in concrete application

Pulverized coal combusts in thermal power plants, producing a complicated mixture of anthropogenic elements such as coal fly ash. If these materials are disposed in landfills and rivers, they constitute a significant hazard to environmental (air and water) pollution. Over the last two decades, research and attempts have been made to limit the generation of coal fly ash and to derive potentially useful elements from it. Industrial wastes such as fly ash, ceramic waste, silica fume, quarry dust, and ground granulated blast furnace slag (GGBS) are substituted for cement or sand to improve the qualities of the concrete. They also save money and can be used as an alternative to waste disposal. Cenosphere, a result of industrial waste coal fly ash, is a low-density and spherical substance that is commonly utilized in the building sector. The paper provides a critical review of formation, synthesis, and use of cenospheres in many domains such as industrial and constructional sector.

Neither remnants nor commodities: Spirit objects in early twentieth century Chinese regional fiction

This paper examines the regional fiction of early twentieth century China in order to understand how such texts presented the object world of rural life. In doing so it addresses a gap in the historiography of material culture in modern China, which has emphasized urban commodity regimes and has paid far less attention to the ways in which pre-existing object practices endured into the time of the modern Republic. Building off of the methodological insights of scholars such as Bill Brownand Janet Poole regarding the contribution that literary study can make to historical understandings of material cultures, this paper argues that the regional texts of Lu Xun, Xu Qinwen, Ye Shengtao, and Yu Dafu were bewitched by overlapping life worlds: one represented by the secular rationalism of the text's narrators, and the other represented by the animistic practices of the rural others they encounter, which was expressed through objects such as joss sticks, temple doorsills, and ancestral alters. These literary works reflected upon how objects were used to make meaning in ways that were not reducible to urban commodity fetishism or remnant “superstition.” As presented in these works, spiritual objects remain powerfully active parts of the affective worlds of rural people, collapsing binary distinctions between living language and inanimate matter, the human and the ghostly, the past and the present. For the narrators of these texts, these object practices invoke a complicated mixture of modernizing critique and empathetic recognition. As such, these texts allow readers to witness the early expressions of a complex dialectic of rejection and recognition/accommodation that has marked the attitude modernizing states in China have taken in relation to animistic material cultures over the past century.

Investigation into the Application of Cissus Populnea as Drilling Fluid Additive (Viscosifier) for Water Based Mud

Progress in drilling engineering demands more sophistication from the drilling mud in order to enhance the usage of drilling fluids, hence numerous additives were introduced, and a simple fluid became a complicated mixture of liquid, solid and chemicals. Some of the challenges with the existing drilling fluid additives has to do with compatibility, degradability, safety, cost, and environmental friendliness. Studies have been carried out on the economic benefits of Cissus Populnea which includes in areas of food, medicine, shelter, and transport but much attention has been paid to its applications in the Oil and Gas industry. This study investigates the rheological properties of Cissus Populnea for application as drilling fluid additive (viscosifier) in Water Based Drilling Mud. Fresh roots, stems and leaves of cissus populnea were sourced from Bayara, Bauchi State. Some liquid exudates of cissus populnea were collected and stored for analysis while some of the samples were dried and grinded in to powdered form. Exudate of the samples were characterized by FTIR, XRD and XRF. Drilling mud was formulated with the samples cisssus populnea and bentonite at different temperatures. The rheology of the formulated drilling mud was investigated and compared with that formulated using bentonite and carboxymethyl cellulose (CMC). Results from X-ray Fluorescence analysis show that the chemical composition of Cissus populnea stem and root are similar when comparing their major components (In2O3 and CaO), while that of leaf has its major components to be In2O3 and Cl. Therefore, in this research work, experiments were conducted with only stem and leaf since stem and roots have common features. From the results of FTIR spectra, the stem of cissus populnea has an OH peak wavelength of 3487.42 cm-1 while that of leave is 3340.82 cm-1. The diffractogram of the stem of cissus populnea was observed at 2q = 22.67o which is very close to that of CMC (2? = 20.31o) while the intense peaks of leaf were observed at around 28.65o. Viscosity of cissus populnea was investigated and found to be decreasing with the increase in temperature for stem exudate. While for leaf exudate, the viscosity was rather increasing with the increase in temperature at temperatures below 35 oC and then continue to decrease with the increase in temperature. The outcome of this research has confirmed the applicability of cissus populnea for drilling fluid additives, viscosifier.

Investigation into the Application of Cissus Populnea as Drilling Fluid Additive (Viscosifier) for Water Based Mud

Progress in drilling engineering demands more sophistication from the drilling mud in order to enhance the usage of drilling fluids, hence numerous additives were introduced, and a simple fluid became a complicated mixture of liquid, solid and chemicals. Some of the challenges with the existing drilling fluid additives has to do with compatibility, degradability, safety, cost, and environmental friendliness. Studies have been carried out on the economic benefits of Cissus Populnea which includes in areas of food, medicine, shelter, and transport but much attention has been paid to its applications in the Oil and Gas industry. This study investigates the rheological properties of Cissus Populnea for application as drilling fluid additive (viscosifier) in Water Based Drilling Mud. Fresh roots, stems and leaves of cissus populnea were sourced from Bayara, Bauchi State. Some liquid exudates of cissus populnea were collected and stored for analysis while some of the samples were dried and grinded in to powdered form. Exudate of the samples were characterized by FTIR, XRD and XRF. Drilling mud was formulated with the samples cisssus populnea and bentonite at different temperatures. The rheology of the formulated drilling mud was investigated and compared with that formulated using bentonite and carboxymethyl cellulose (CMC). Results from X-ray Fluorescence analysis show that the chemical composition of Cissus populnea stem and root are similar when comparing their major components (In2O3 and CaO), while that of leaf has its major components to be In2O3 and Cl. Therefore, in this research work, experiments were conducted with only stem and leaf since stem and roots have common features. From the results of FTIR spectra, the stem of cissus populnea has an OH peak wavelength of 3487.42 cm-1 while that of leave is 3340.82 cm-1. The diffractogram of the stem of cissus populnea was observed at 2q = 22.67o which is very close to that of CMC (2θ = 20.31o) while the intense peaks of leaf were observed at around 28.65o. Viscosity of cissus populnea was investigated and found to be decreasing with the increase in temperature for stem exudate. While for leaf exudate, the viscosity was rather increasing with the increase in temperature at temperatures below 35 oC and then continue to decrease with the increase in temperature. The outcome of this research has confirmed the applicability of cissus populnea for drilling fluid additives, viscosifier.

Nonparametric Multivariate Density Estimation: Case Study of Cauchy Mixture Model

Estimation of probability density functions (pdf) is considered an essential part of statistical modelling. Heteroskedasticity and outliers are the problems that make data analysis harder. The Cauchy mixture model helps us to cover both of them. This paper studies five different significant types of non-parametric multivariate density estimation techniques algorithmically and empirically. At the same time, we do not make assumptions about the origin of data from any known parametric families of distribution. The method of the inversion formula is made when the cluster of noise is involved in the general mixture model. The effectiveness of the method is demonstrated through a simulation study. The relationship between the accuracy of evaluation and complicated multidimensional Cauchy mixture models (CMM) is analyzed using the Monte Carlo method. For larger dimensions (d ~ 5) and small samples (n ~ 50), the adaptive kernel method is recommended. If the sample is n ~ 100, it is recommended to use a modified inversion formula (MIDE). It is better for larger samples with overlapping distributions to use a semi-parametric kernel estimation and more isolated distribution-modified inversion methods. For the mean absolute percentage error, it is recommended to use a semi-parametric kernel estimation when the sample has overlapping distributions. In the smaller dimensions (d = 2) and a sample is with overlapping distributions, it is recommended to use the semi-parametric kernel method (SKDE) and for isolated distributions, it is recommended to use modified inversion formula (MIDE). The inversion formula algorithm shows that with noise cluster, the results of the inversion formula improved significantly.

Dual-gating pH-responsive membranes with the heterogeneous structure for whey protein fractionation

Whey protein is a mixture of globular proteins with high nutritional value and excellent functional properties availability. Purified individual whey proteins exhibit better functionality than in their original mixture, thus there is an increasing interest in developing more efficient methods to recover individual whey protein fractions, especially membrane technology. However, whey protein fractionation from the protein mixture is still a huge challenge for membrane separation. Herein, a dual-gating pHresponsive membrane with the heterogeneous structure was developed for whey protein fractionation. The heterogeneous structure of the membranes was obtained by grafting the dimethylaminoethyl methacrylate (DMAEMA) and 4-vinylpyridine (4VP) near the topside and inside the pores of the ethylene vinyl alcohol copolymer (EVAL) membranes based on selective modification of grafting sites. The PDMAEMA and P4VP gates responded to pH individually and provided a multi-stage regulation of the surface charge and sieving property of the membranes. The major whey protein fractionation from the mixture could be achieved by single dual-gating pH-responsive membrane via the sequential stepwise pH gradient from 3.0 to 8.0. The α-Lactalbumin (α-La), β-Lactoglobulin (β-Lg), lactoferrin (LF) and bovine serum albumin (BSA) were separated and enriched in the permeate at pH 3.0, 4.2, 6.4 and 8.0 by the diafiltration process, respectively. This work not only proposed a novel concept of pHresponsive membrane, but also offered a sustainable solution to fractionate the whey protein from the complicated mixture.

Applications of chromatography in giant complex drug-organism system

色谱是一门以分离分析为主,旨在追求复杂事物纯而净的分析化学的重要分支学科。其经过百余年的发展,理论与技术日臻完善,集科学、技术与艺术于一体。近年来,色谱及其与质谱、核磁共振波谱、原子发射光谱等联用技术极大推动了环境、食品、石油化工、生物医药等领域中所涉及复杂体系的研究进展。作为我国传统文化的核心代表,中医药为中国乃至世界人民的健康服务逾千年,从古至今历经上千年临床考验,疗效经久不衰。近年来,中国政府强调继承与创新,加大推进中医药的现代化与国际化。然而中药自身的多成分协同起效复杂性及其与机体时刻新陈代谢变化的复杂性往往相互作用,由此形成了药物-机体复杂巨系统。该复杂巨系统的分析研究是中医药现代化进程的关键瓶颈。色谱的优势在于复杂成分的分离与分析,此恰能为上述复杂巨系统提供技术支撑,色谱及其联用技术已成为推动中医药分子化、数字化、信息化乃至现代化的主流技术。该文综述了色谱及其联用技术在中药复杂体系、复杂生命过程及药物-机体复杂巨系统中的应用进展,介绍了笔者研究团队对中医药现代化的认识、研究思路和研究工作,最后笔者结合对于百年色谱与千年中医药文化之现代化交织的感悟,对色谱技术在此领域的前景做出了展望。

Prevalence of Naturally Occurring Resistance Associated Substitutions in NS3/4AProtease Inhibitors in Iranian HCV/HIV Infected Patients.

Hepatitis C virus (HCV) acts in the host as a complicated mixture of related variants with the potency to genetically escape host immune responses. Direct acting antivirals (DAAs) have been approved for HCV treatment with shorter duration, better cure rates and lower side effects. However, naturally occurring resistance associated substitutions (RASs) create some obstacles to this antiviral therapy success. In this study, we aimed at the determination of the naturally occurring NS3/4A RASs in HCV/human immunodeficiency virus (HIV)infected patients. A total of 120 DAA-naïve HCV-HIV co-infected patients were included. HCV NS3/4Agenome region was amplified with PCR and mutation analysis was performed by Sanger sequencing technique. The amino acid sequence diversity of the region was analyzed using geno2pheno HCV. Phylogenetic analysis showed that 73 cases were infected by 3a and 47 subjects by subtype1a. The overall RASs among studied subjects were observed in 6 (5%) individuals from 120 studied cases who were infected with HCV 1a. V36M/L, Q80L, S122G/L, R155T/G, A156S, D168Y/N and S174A/N/T mutations were detected in this study. Although the prevalence of RASs was totally low in this study, the presence of several cases of double and triple mutants among this population suggests prior evaluation of protease inhibitors related mutations before initiation of standard treatment and also an investigation on a large population could be of high value.

Valorization of a spent lithium-ion battery electrolyte through syngas formation using CO2-assisted catalytic thermolysis over a battery cathode material

Development of rechargeable batteries in energy storage systems and electric/electronic devices has been rapidly progressed as an effort to amplify the utilization renewable and sustainable energies since the past few decades. However, increasing demand of the rechargeable batteries results in significant accumulation of battery waste materials. In the current battery recycling process, the recovery of cathode metal(oxide)s has been mainly focused, but other organic compartments were not properly recycled. In this study, the valorization of battery electrolyte was investigated. To this end, CO2-assisted thermolysis of a broadly used battery electrolyte, LiPF6 in carbonate solvents, was performed. First part examined liquid (carbonates, cyclic and aliphatic hydrocarbons) and gaseous products (H2, CO, CH4, C2H4, and CO2) from thermolysis of battery electrolyte at different conditions. The complicated mixture of pyrogenic products needs additional separation processes to recover each compound. To convert the complicated mixture samples into value-added chemicals (i.e., syngas), catalytic thermolysis was done in the second part. Considering that the practical pyrolysis condition of battery electrolyte includes a cathode material during the thermolysis, a conventional cathode material (NCM 811: LiNi0.8Co0.1Mn0.1O2) was used as a catalyst. It was highly active to convert entire liquid compounds into syngas at ≤ 500 °C, and synergistic effects of catalyst and CO2 resulted in enhanced CO formation. Given that the metallurgy process for battery operates at near 1300 °C, thermolysis of battery electrolyte could be incorporated into the metallurgy process to maximize recovery of organic and metallic compounds in spent batteries.

Phenolics from Mangifera Indica (Tommy Atkins) peels and assessment of its Anticancer Activity

The aim of this study is to investigate the chemical and biological activity of Mangifera indica L. cv. peels extract, resulted that the methanolic extract of Mangifera indica L. cv. peels contains a complicated mixture of phenolics, which includes mainly gallotannins as previously detected by 2D paper chromatographic screening. and characterized by high-performance liquid chromatography (HPLC)to prove the presence of 13 compounds, five major compounds namely, Gallic acid (24621.70 µg/g), Naringenin(2624.57µg/g), vanillin (1322.85µg/g), Catechin(12681.37µg/g), Chlorogenic acid(638.08µg/g). potentially biologically active methanolic extract becomes much more efficient after identification of all compounds in that mixture. The invitro Cytotoxic activities by using SRB assay, of methanolic extract from mango (Mangifera indica L. cv. “Tommy Atkins”) peels Moderately effective against Cervical (HELA) cell line with IC50 25μg/ml. and weakly effective against Breast (MCF7) cell line with IC50 44 μg/ml. All identified phenolic compounds are therapeutically active compounds with anticancer potency which was reported for the first time.

Fabrication of void-free submillimeter-scale nickel component by bottom-up electrodeposition

This study proposed and demonstrated the feasibility of adopting metallization method of bottom-up Damascene process (seed layer over entire patterned surface) in LIGA electrodeposition process to fabricate void-free submilimeter scale metallic components. Single additive (PEG of molecular weight, Mw 10,000) rather than complicated mixture of multiple additives is studied in order to simplify the additives concentration monitoring process. Hydrodynamic flow pattern and concentration distribution of additive in the electrolyte flowing across trenches of various aspect ratio were studied by using fluid kinetics simulation. Simulation results showed the shear flow of the agitated electrolyte across the top surface caused the formation of a concentration gradient of inhibitor (PEG) within the cavity, in which the concentration of inhibitor at the top surface was consistently maintained at a higher level as compared to the bottom part of cavity. The studies on the influence of PEG concentration on electrodeposition profile showed a relatively low concentration of 10 ppm has exhibited a remarkable difference in the electrodeposition rate at the top and inner surfaces of submillimeter cavity (bottom-up electrodeposition) which subsequently eliminated the formation of void/seam-like defects associated with conventional electrodeposition. Underfilling issue was identified and a two-step electrodeposition method was proposed to mitigate the underfilling effect. Nickel component electrodeposited by PEG-added electrolyte shows higher Vickers hardness of approximately 20% as compared to additive-free sample. Flat and thin surface layer that has been electrodeposited using this technique suggested a low risk of parts’ peel-off. This resulted in the simplified process of surface polishing, planarization and demolding. This approach provides an insight into fabrication techniques for void-free multilayer, millimeter-scaled components like watch parts.

CDAE: A Cascade of Denoising Autoencoders for Noise Reduction in the Clustering of Single-Particle Cryo-EM Images.

As an emerging technology, cryo-electron microscopy (cryo-EM) has attracted more and more research interests from both structural biology and computer science, because many challenging computational tasks are involved in the processing of cryo-EM images. An important image processing step is to cluster the 2D cryo-EM images according to their projection angles, then the cluster mean images are used for the subsequent 3D reconstruction. However, cryo-EM images are quite noisy and denoising them is not easy, because the noise is a complicated mixture from samples and hardware. In this study, we design an effective cryo-EM image denoising model, CDAE, i.e., a cascade of denoising autoencoders. The new model comprises stacked blocks of deep neural networks to reduce noise in a progressive manner. Each block contains a convolutional autoencoder, pre-trained by simulated data of different SNRs and fine-tuned by target data set. We assess this new model on three simulated test sets and a real data set. CDAE achieves very competitive PSNR (peak signal-to-noise ratio) in the comparison of the state-of-the-art image denoising methods. Moreover, the denoised images have significantly enhanced clustering results compared to original image features or high-level abstraction features obtained by other deep neural networks. Both quantitative and visualized results demonstrate the good performance of CDAE for the noise reduction in clustering single-particle cryo-EM images.

A Gated Recurrent Network With Dual Classification Assistance for Smoke Semantic Segmentation.

Smoke has semi-transparency property leading to highly complicated mixture of background and smoke. Sparse or small smoke is visually inconspicuous, and its boundary is often ambiguous. These reasons result in a very challenging task of separating smoke from a single image. To solve these problems, we propose a Classification-assisted Gated Recurrent Network (CGRNet) for smoke semantic segmentation. To discriminate smoke and smoke-like objects, we present a smoke segmentation strategy with dual classification assistance. Our classification module outputs two prediction probabilities for smoke. The first assistance is to use one probability to explicitly regulate the segmentation module for accuracy improvement by supervising a cross-entropy classification loss. The second one is to multiply the segmentation result by another probability for further refinement. This dual classification assistance greatly improves performance at image level. In the segmentation module, we design an Attention Convolutional GRU module (Att-ConvGRU) to learn the long-range context dependence of features. To perceive small or inconspicuous smoke, we design a Multi-scale Context Contrasted Local Feature structure (MCCL) and a Dense Pyramid Pooling Module (DPPM) for improving the representation ability of our network. Extensive experiments validate that our method significantly outperforms existing state-of-art algorithms on smoke datasets, and also obtain satisfactory results on challenging images with inconspicuous smoke and smoke-like objects.