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Within the stirred-tank flocculating system under equivalent shear-rate (Gave) cases, the effects of both reactor shape (cylindrical or square) and baffles on floc morphological evolution during flocculation were investigated by applying flocculation tests with the aid of computational fluid dynamics (CFD) simulations. At a constant Gave, the recirculating times for those floc aggregates existing in water flow to the impeller region and the intensity of turbulence occurring within this region, together with the non-uniform nature of turbulence for water flow above the rotating impeller, were found to be distinct in the various stirred-tank reactors investigated, thereby affecting the development of floc size and structure. Besides, the importance of reactor shape and baffles to floc morphological evolution seemed to be largely determined by predominant growth behavior(s). For aggregation-dominated circumstances, the baffled square stirred tank formed the largest and most compact floc aggregates among all reactors, due to the most visiting times for pre-formed micro-floc aggregates to the highest turbulent-intensity impeller region; while for breakage-dominated circumstances, the most non-uniform distributions of turbulent water flow were generated via impeller-baffle interactions in this reactor, thereby giving the highest breakage rate and producing the smallest floc aggregates with the smoothest and most compact structures.

The impeller clearance (C) and shear rate (Gave) effects on aggregation and breakage behaviors in the whole process of floc growth were investigated by applying lab-scale flocculation tests with the aid of computational fluid dynamics (CFD) simulations. For a baffled square stirred-tank flocculating reactor, the recirculating times for water flow to the impeller region and intensity of turbulence occurring within this region, together with the non-uniform nature of turbulence for water flow above the rotating impeller, were found to be more or less different in all C-value cases at a constant Gave, thereby affecting the development of floc morphology. Besides, the importance of impeller clearance (C) to floc morphological evolution seemed to be largely determined by predominant growth behavior(s), likely as a result of distinct occurring degrees of either aggregation or breakage for each combination of C and Gave; and interestingly, a certain compaction for the above effect took place at a relatively high shear, possibly attributed to increasingly pronounced occurrence of floc breakage and irreversibility of this behavior. To produce fractal flocs with favorable morphological characteristics, the impeller should be placed at an appropriate distance from the reactor bottom within the flocculating system, under whether aggregation-dominated or breakage-dominated circumstances, for weakening the role of reactor bottom and water surface on floc growth behaviors during flocculation. This research would be beneficial for thoroughly understanding floc formation mechanisms and optimally designing impeller-based flocculating reactors.

For enhancing the understanding of ballasted flocculation (BF) mechanisms, a series of BF tests were performed to explore the coagulant dosage and mixing intensity effects on floc growth behaviors and corresponding particle settling by using coagulants of aluminum sulphate (AS) or polyaluminum chloride (PACl). As expected, different coagulant dosages brought about distinct surface charge characteristics of micro-floc aggregates after either Al-based coagulant addition, thereby affecting the development of ballasted floc size. More specifically, the higher the coagulant dosage was, the more the cationic hydrolyzed-Al species were produced, leading to a requirement of more binding sites on the injected polymer for bridging between micro-flocs and ballasting agent (BA) particles, and accordingly, the degree to which BA particles had been incorporated into the aggregate matrix seemed to largely account for ballasted floc formation. Besides, floc aggregates formed after breakage appeared larger than those after maturation, especially at higher coagulant dosages, possibly caused by a stretched conformation of long polymer chains providing more binding sites available within a higher-shear suspension. In an operational sense, poor incorporation should be maximally eliminated, since this undesirable behavior could produce a greater number of resultant flocs with fewer or even no BA particles, thus worsening the settling performance. This research would be helpful for thoroughly understanding ballasted floc formation mechanisms in either water or wastewater treatment operations.

Through regulating the in-band absorption of used gain fiber, we demonstrate an ultra-broadband tunable and switchable multi-wavelength mode-locking Tm-doped all-fiber laser. The tuning range can be enlarged as much as 153 nm (from 1828.45 to 1981.35 nm, the largest tuning range so far) by employing different lengths of used gain fiber with different in-band absorption and birefringent filtering mechanism. In addition, benefiting from four in-line polarization controllers and broadband gain profile of Tm-doped fiber, switchable quad-wavelength mode locking with part binary control can be observed clearly, even penta-wavelength. Such kind of ultra-broadband tunable and switchable mode-locking laser provide simpler and elastic way for practical application, such as optical signal processing, spectroscopy, optical communications, and so on.

The effects of global warming and anthropogenic disturbance force animals to migrate from lower to higher elevations to find suitable new habitats. As such migrations increase hypoxic stress on the animals, it is important to understand how plateau- and plain-dwelling animals respond to low-oxygen environments. We used comparative transcriptomics to explore the response of Neodon fuscus, Lasiopodomys brandtii, and Mus musculus skeletal muscle tissues to hypoxic conditions. Results indicate that these species have adopted different oxygen transport and energy metabolism strategies for dealing with a hypoxic environment. N. fuscus promotes oxygen transport by increasing hemoglobin synthesis and reduces the risk of thrombosis through cooperative regulation of genes, including Fga, Fgb, Alb, and Ttr; genes such as Acs16, Gpat4, and Ndufb7 are involved in regulating lipid synthesis, fatty acid β-oxidation, hemoglobin synthesis, and electron-linked transmission, thereby maintaining a normal energy supply in hypoxic conditions. In contrast, the oxygen-carrying capacity and angiogenesis of red blood cells in L. brandtii are promoted by genes in the CYP and COL families; this species maintains its bodily energy supply by enhancing the pentose phosphate pathway and mitochondrial fatty acid synthesis pathway. However, under hypoxia, M. musculus cannot effectively transport additional oxygen; thus, its cell cycle, proliferation, and migration are somewhat affected. Given its lack of hypoxic tolerance experience, M. musculus also shows significantly reduced oxidative phosphorylation levels under hypoxic conditions. Our results suggest that the glucose capacity of M. musculus skeletal muscle does not provide sufficient energy during hypoxia; thus, we hypothesize that it supplements its bodily energy by synthesizing ketone bodies. For the first time, we describe the energy metabolism pathways of N. fuscus and L. brandtii skeletal muscle tissues under hypoxic conditions. Our findings, therefore, improve our understanding of how vertebrates thrive in high altitude and plain habitats when faced with hypoxic conditions.

MicroRNAs are emerging as critical endogenous regulators of gene function. Aberrant regulation of microRNAs is associated with various human diseases, most importantly cancer. MicroRNA-122 (miR-122), a liver-specific microRNA, has been implicated in the control of hepatitis C virus (HCV) RNA replication and its response to interferon (IFN) in human hepatoma cells. Here, we report that daidzein, a naturally occurring plant isoflavone, inhibits HCV replication and enhances the antiviral effect of IFN-α on HCV therapy by decreasing microRNA-122 levels in vitro without significantly affecting cell growth. Moreover, daidzein was found to inhibit the expression of miR-122 and miR-21 by down-regulating the expression of TRBP, indicating that daidzein is possibly a general inhibitor of the miRNA pathway. Thus, daidzein provides new insights for drug discovery and HCV prevention.

Concise stereoselective syntheses of (−)-clavaminol A and deacetyl (+)-clavaminol H have been achieved from simple starting materials. Highlights of the synthesis for (−)-clavaminol A include a highly diastereoselective chelation-controlled hydride reduction of an amino ketone to give the anti amino alcohol directly, and NaBH 4 -mediated dehalogenation. The main synthetic approach for deacetyl (+)-clavaminol H features a highly diastereoselective chelation-controlled hydride reduction of the amino ketone to construct the anti amino alcohol and a palladium catalyzed hydrogenation reaction at the final step.

The glyoxalase system is a ubiquitous enzymatic network which plays important roles in biological life. It consists of glyoxalase 1 (GLO1), glyoxalase 2 (GLO2), and reduced glutathione (GSH), which perform an essential metabolic function in cells by detoxifying methylglyoxal (MG) and other endogenous harmful metabolites into non-toxic d-lactate. MG and MG-derived advanced glycation endproducts (AGEs) are associated with various diseases, such as diabetes, cardiovascular disease, neurodegenerative disorders and cancer, and GLO1 is a key rate-limiting enzyme in the anti-glycation defense. The abnormal activity and expression of GLO1 in various diseases make this enzyme a promising target for drug design and development. This review focuses on the regulatory mechanism of GLO1 in diverse pathogenic conditions with a thorough discussion of GLO1 regulators since their discovery, including GLO1 activators and inhibitors. The different classes, chemical structure and structure-activity relationship are embraced. Moreover, assays for the discovery of small molecule regulators of the glyoxalase system are also introduced in this article. Compared with spectrophotometer-based assay, microplate-based assay is a more simple, rapid and quantitative high-throughput method. This review will be useful to design novel and potent GLO1 regulators and hopefully provide a convenient reference for researchers.

Nanostructure of catalysts plays a critical role in catalytic activity and durability. Herein, a ceria nanorod catalyst, CeO2(NR), was designed and synthesized, and the relationships between nanostructure and catalytic activity as well as aging resistibility were investigated. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction results indicate that the nanorod structure of CeO2(NR) can be well maintained after aging at 900 °C for 8 h and can prevent the excessive expansion of crystals during high-temperature aging. X-ray photoelectron spectroscopy and hydrogen temperature-programmed reduction results suggest that the CeO2(NR) nanorod has distinctly more oxygen vacancies than the CeO2 nanoparticle; moreover the nanorod structure of CeO2(NR) and CeO2(NR)-A can enhance the lattice oxygen mobility and contribute to the spillover of lattice oxygen to form surface active oxygen during high temperature reaction. Finally, the catalytic activity tests indicate that the synthesized CeO2(NR) nanorod catalyst displays significantly better soot purification efficiency and intrinsic activity for soot oxidation; more than that, this superior catalytic activity of CeO2(NR) is well maintained after high-temperature thermal aging. Thus, this work suggests that the nanorod structure of ceria-based catalysts plays a key role in enhancing aging resistibility and catalytic soot oxidation activity.

Glyoxalase I (GLO1) is a homodimeric Zn2+-metalloenzyme that catalyses the transformation of methylglyoxal (MG) to d-lacate through the intermediate S-d-lactoylglutathione. Growing evidence indicates that GLO1 has been identified as a potential target for the treatment cancer and other diseases. Various inhibitors of GLO1 have been discovered or developed over the past several decades including natural or natural product-based inhibitors, GSH-based inhibitors, non-GSH-based inhibitors, etc. The aim of this review is to summarize recent achievements of concerning discovery, design strategies, as well as pharmacological aspects of GLO1 inhibitors with the target of promoting their development toward clinical application.