Recent Advances In Separation Research Articles

Recent Advances in Separation and Analysis of Chiral Compounds.

Recent Advances in Separation and Analysis of Chiral Compounds.

Recent Advances in Separation and Analysis of Saponins in Natural Products

To better control the quality of saponins, ensure their biological activity and clinical therapeutic effect, and expand the development and application of saponins, this paper systematically and comprehensively reviews the separation and analytical methods of saponins in the past decade. Since 2010, the electronic databases of PubMed, Google Scholar, ISI Web of Science, Science Direct, Wiley, Springer, CNKI (National Knowledge Infrastructure, CNKI), Wanfang Med online, and other databases have been searched systematically. As a result, it is found that ionic liquids and high-performance countercurrent chromatography are the most popular extraction and separation techniques for saponins, and the combined chromatography technique is the most widely used method for the analysis of saponins. Liquid chromatography can be used in combination with different detectors to achieve qualitative or quantitative analysis and quality control of saponin compounds in medicinal materials and their preparations. This paper provides the latest valuable insights and references for the analytical methods and continued development and application of saponins.

Advanced Regenerative Medicine Strategies for Treatment of Perianal Fistula in Crohn's Disease.

Regenerative medicine is an emerging therapeutic method that aims to reconstruct tissues and organs. This advanced therapeutic approach has demonstrated great potential in addressing the limitations of medical and surgical procedures for treating perineal fistula in patients with Crohn's disease. Recent developments in stem cell technology have led to a massive good manufacturing practices (GMPs) production of various stem cells, including mesenchymal and embryonic cells, along with induction of pluripotent stem cells to repair damaged tissues in the fistula. The recent advances in separation and purification of exosomes, as biologic nanovesicles carrying anti-inflammatory and regenerative agents, have made them powerful tools to treat this inflammatory disease. Further, tremendous advances in nanotechnology, biomaterials, and scaffold fabrication methods enable tissue engineering methods to synthesize tissue-like structures to assist surgical techniques. This review focuses on advanced regenerative-based methods including stem cell therapy, exosome therapy, and tissue engineering used in the treatment of perianal fistula. Relevant in vitro and in vivo studies and the latest innovations in implementation of regenerative medicine for this disease are also separately reviewed. Additionally, current challenges regarding implementation of g stem cells, exosomes, and tissue engineering methods for bridging the gaps between laboratory findings and clinic application will be discussed.

Separation of Xylene Isomers: A Review of Recent Advances in Materials

The xylene isomers p-xylene, o-xylene, and m-xylene are aromatic hydrocarbons comprising with two methyl groups located at different positions on a benzene ring. The mixture originates from catalytic reforming of crude oil, and each individual isomer acts as a valuable intermediate; however, similar physicochemical properties make their separation difficult. This Review focuses on materials employed for their separation, such as metal–organic frameworks, molecular sieves, organics, and graphene quantum dots. Recent advances in separation of xylene isomers are summarized, including adsorption, membrane, and chromatographic separation techniques, and adsorption capacity and selectivity combined with mechanisms of separation are discussed.

Downstream process development in biotechnological itaconic acid manufacturing.

Itaconic acid is a promising chemical that has a wide range of applications and can be obtained in large scale using fermentation processes. One of the most important uses of this biomonomer is the environmentally sustainable production of biopolymers. Separation of itaconic acid from the fermented broth has a considerable impact in the total production cost. Therefore, optimization and high efficiency downstream processes are technological challenges to make biorefineries sustainable and economically viable. This review describes the current state of the art in recovery and purification for itaconic acid production via bioprocesses. Previous studies on the separation of itaconic acid relying on operations such as crystallization, precipitation, extraction, electrodialysis, diafiltration, pertraction, and adsorption. Although crystallization is a typical method of itaconic acid separation from fermented broth, other methods such as membrane separation and reactive extraction are promising as a recovery steps coupled to the fermentation, potentially enhancing the overall process yield. Another approach is adsorption in fixed bed columns, which efficiently separates itaconic acid. Despite recent advances in separation and recovery methods, there is still space for improvement in IA recovery and purification.

Separation Logic for High-Level Synthesis

High-Level Synthesis (HLS) promises a significant shortening of the FPGA design cycle by raising the abstraction level of the design entry to high-level languages such as C/C++. However, applications using dynamic, pointer-based data structures and dynamic memory allocation remain difficult to implement well, yet such constructs are widely used in software. Automated optimizations that leverage the memory bandwidth of FPGAs by distributing the application data over separate banks of on-chip memory are often ineffective in the presence of dynamic data structures due to the lack of an automated analysis of pointer-based memory accesses. In this work, we take a step toward closing this gap. We present a static analysis for pointer-manipulating programs that automatically splits heap-allocated data structures into disjoint, independent regions. The analysis leverages recent advances in separation logic , a theoretical framework for reasoning about heap-allocated data that has been successfully applied in recent software verification tools. Our algorithm focuses on dynamic data structures accessed in loops and is accompanied by automated source-to-source transformations that enable automatic loop parallelization and memory partitioning by off-the-shelf HLS tools. We demonstrate the successful loop parallelization and memory partitioning by our tool flow using three real-life applications that build, traverse, update, and dispose of dynamically allocated data structures. Our case studies, comparing the automatically parallelized to the direct HLS implementations, show an average latency reduction by a factor of 2 × across our benchmarks.

分離・濃縮による鉄鋼微量成分分析の発展

Accurate chemical analysis of iron and steel for trace elements usually requires appropriate separation and preconcentration procedures prior to instrumental measurements of analytes. The present review is concerned exclusively with recent advances in separation and preconcentration techniques, including liquid-liquid extraction, ion exchange, solid-phase extraction, coprecipitation, volatilization and electrolysis.

A Survey of Specularity Removal Methods

AbstractThe separation of reflection components is an important issue in computer graphics, computer vision and image processing. It provides useful information for the applications that need consistent object surface appearance, such as stereo reconstruction, visual recognition, tracking, objects re‐illumination and dichromatic editing. In this paper we will present a brief survey of recent advances in separation of reflection components, also known as specularity (highlights) removal. Several techniques that try to tackle the problem from different points of view have been proposed so far. In this survey, we will overview these methods and we will present a critical analysis of their benefits and drawbacks.

Recent advances in separation of roughness, waviness and form

Engineering surfaces are comprised of a range of spatial wavelengths. Filtering techniques are commonly adopted to separate the different wavelength components into well-defined bandwidths. Filtering is done prior to numerical characterization and it is also essential for extracting information needed to provide process feedback and establish functional correlation. This paper reviews commonly used filters in surface metrology like the 2RC, Gaussian and several new ones currently under research such as the spline, morphological, wavelets, regression filters and robust regression filters. The need for these new filters and examples illustrating the features of these filters are also presented.

Development of a lifting wavelet representation for surface characterization

This paper reviews the existing numerical analysis methods and their problems in surface metrology. Based on the requirements of functional analysis of surfaces, this paper proposes a lifting wavelet representation for extraction of different components of a surface. The theory of the lifting wavelet is introduced and a fast algorithm is developed. Different frequency components of the surface can be separated, extracted and then reconstructed according the intended requirements of functional analysis. The surface textures can be highlighted and multi-scalar topographical features can be identified and clearly recovered. In order to verify the behaviour of the new model, a computer simulation based on sinusoidal and triangular waveforms is used. Case studies are conducted using a series of typical surfaces of engineering and bioengineering, such as planes, cylinders and curves, measured by contact (stylus) and non-contact (phase-shifting interferometry) instruments, to demonstrate the feasibility and applicability of using the lifting wavelet model in the analysis of these surfaces.

Recent advances in separation of metals by liquid surfactant membranes.

In this paper, recent advances in the separation of metals by liquid surfactant membranes are reviewed, with emphasis placed on development of a suitable surfactant.In establishing a metal recovery process using liquid surfactant membranes, the choice of a suitable surfactant is a key factor. It is important to elucidate the role of the surfactant on the behavior of liquid surfactant membranes, e.g., the break-up rate and the swelling rate of W/O emulsion glubules in a mixer, the demulsirication rate of the emulsions in an electrical coalescer and the extraction rate of metal by liquid surfactant membranes. These problems are discussed. The application of liquid surfactant membranes to the metal separation processes is also described.

Mixed products of thymine and cysteine produced by direct and acetone-sensitized photoreactions.

Abstract. The nature of the major mixed products of the photoreaction of thymine with L‐cysteine has been restudied. Our results, from application of recent advances in separation and spectroscopic technology to this problem, allow extension and require major revision of the published descriptions of the products produced in this system. We have found that the previously described major mixed photoproduct in the system, 5‐S‐L‐cysteinyl‐5, 6‐dihydrothymine, can be readily separated into diasteromers (Ia and Ib) that have quite different chromatographic and NMR spectral properties. Confirming previously published work, 5‐S‐L‐cysteinylmethyluracil (III) was also produced. Major modifications in the published descriptions of other mixed photoproducts produced in the photoreaction of thymine with cysteine are the following. While the product 5‐S‐L‐cysteinylmethyl‐5, 6‐dihydrouracil (II) is indeed produced, it does not correspond in its properties to the compound previously reported as this substance. Our experimental findings also indicate that observations, previously interpreted to imply formation of the disulfide 5‐S, S‐L‐cysteinyl‐5, 6‐dihydrothymine (IV), can instead be explained in terms of the properties of the β‐carbamoylsulfide functionality contained in Ia and Ib. Indeed, both diastereomers of the addition product of L‐cysteine with N‐ethylmaleimide, S‐(l‐ethyl‐2, 5‐dioxopyrrol‐idin‐3‐yl)‐L‐cysteine (VI), as well as 5‐carbamoyl‐4‐thiapentanoic acid (VII), exhibit properties assumed in the previous work to be specific to disulfide linkages; each of these compounds contains a β‐carbamoylsulfide functionality. Acetone photosensitization of reaction in the thymine‐cysteine system also yielded Ia, Ib, II and III as products. Again, no evidence was found for formation of IV.

Lipids of the cell plasma membrane.

Cellular interfaces are Known to contain large quantities of lipids. The concept of the molecular organization of these membranes is still in a state of flux and many attempts are being made to evaluate more precisely the contribution of lipids to the properties of the biological interfaces. Recent advances in separation and analytical techniques have made it possible to isolate pure membrane preparations and to determine their detailed lipid composition (48, 57]. The emphasis of this paper will be placed on the plasma membrane, but let it be stated that the plasma membrane is not the putermost envelope for all freely living cells as bacteria, yeast and fungi, though it regulates predominantly the permeability of low-molecular substances. Also the interaction of the intracellular membranes with the function of the cell membrane has to be mentioned. The structure and function of the plasma membrane and other cell membranes have been considered in many papers (e.g. 29, 33, 37, 57).

Chemical and Instrumental Methods of Flavor Analysis

Recent advances in separation, physical measurement equipment, and manipulation techniques have made it possible to obtain information in flavor investigations which were very difficult to study previously. Capacity and resolution of gas-chromatography columns have been improved. Gas chromatography and mass spectrometry have been combined to give information for identification purposes with submicrogram quantities. Nuclear magnetic resonance studies are now possible with submilligram quantities of purified material. Raman spectra are also obtainable with submilligram quantities to supplement infrared spectral data. Thus, chemical structure determinations can now be made with only submilligram quantities with good certainty.