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The emergence of new therapeutic modalities requires complementary tools for their efficient syntheses. Availability of methodologies for site-selective modification of biomolecules remains a long-standing challenge, given the inherent complexity and the presence of repeating residues that bear functional groups with similar reactivity profiles. We describe a bioconjugation strategy for modification of native peptides relying on high site selectivity conveyed by enzymes. We engineered penicillin G acylases to distinguish among free amino moieties of insulin (two at amino termini and an internal lysine) and manipulate cleavable phenylacetamide groups in a programmable manner to form protected insulin derivatives. This enables selective and specific chemical ligation to synthesize homogeneous bioconjugates, improving yield and purity compared to the existing methods, and generally opens avenues in the functionalization of native proteins to access biological probes or drugs.

An efficient method of recovering and recycling solvent for counter-current chromatography was established by which zeaxanthin was separated from Lycium barbarum L. fruits. A column with activated carbon combined with high performance counter-current chromatography formed the recovering and recycling solvent system. Using the solvent system of n-hexane-ethyl acetate-ethanol-water (8:2:7:3, v/v) from the references, five injections were performed with an almost unchanged purity of zeaxanthin (80.9, 81.2, 81.5, 81.3, and 80.2% respectively) in counter-current chromatography separation. Meanwhile, the mobile phase reduced by half than conventional counter-current chromatography. By this present method, an effective improvement of counter-current chromatography solvent utilization was achieved.

The chiral separation by counter-current chromatography has made great progress in the past three decades. It has become increasingly popular in the field of chiral separation, and many applications have been introduced during the last years. This review mainly focuses on the current topics, applications, and trends in chiral separation by counter-current chromatography. It contains the development of modern counter-current chromatography apparatus, theory of counter-current chromatography, overview of applications of chiral counter-current chromatography enantioseparation, its current situation, and challenges. At last, some conclusions and perspectives also have been discussed in this review.

Mesenchymal Stem Cells (MSCs) are distributed in many parts of the human body, including the bone marrow, placenta, umbilical cord, fat, and nasal mucosa. One of the unique features of MSCs is their multidirectional differentiation potential, including the ability to undergo osteogenesis, adipogenesis, and chondrogenesis, and to produce neurons, endothelial cells, Schwann cells, medullary nucleus cells, cardiomyocytes, and alveolar epithelial cells. MSCs have thus become a hot research topic in recent years. Numerous studies have investigated the differentiation of MSCs into various types of cells in vitro and their application to numerous fields. However, most studies have cultured MSCs under atmospheric oxygen tension with an oxygen concentration of 21%, which does not reflect a normal physiological state, given that the oxygen concentration generally used in vitro is four to ten times that to which MSCs would be exposed in the body. We therefore review the growing number of studies exploring the effect of hypoxic preconditioning on the differentiation of MSCs.

Maximal efficiency from enzyme cascades Enzymes are highly selective catalysts that can be useful for specific transformations in organic synthesis. Huffman et al. combined designer enzymes in a multistep cascade reaction (see the Perspective by O'Reilly and Ryan). The approach eliminates purification steps, recycles expensive cofactors, and couples favorable and unfavorable reactions. With the target molecule islatravir, an experimental HIV drug, they optimized five enzymes by directed evolution to be compatible with unnatural substrates and stable in the reaction conditions. Stereochemical purity was amplified at every enzymatic step, and the final synthesis was both atom economical and efficient. Science , this issue p. 1255 ; see also p. 1199

Mesenchymal stem cells (MSCs) play important roles in tissue repair and regeneration, such as the induction of angiogenesis, particularly under hypoxic conditions. However, the molecular mechanisms underlying hypoxic MSC activation remain largely unknown. MSC-derived extracellular vesicles (EVs) are vital mediators of cell-to-cell communication and can be directly utilized as therapeutic agents for tissue repair and regeneration. Here, we explored the effects of EVs from human hypoxic olfactory mucosa MSCs (OM-MSCs) on angiogenesis and its underlying mechanism. EVs were isolated from normoxic (N) OM-MSCs (N-EVs) and hypoxic (H) OM-MSCs (H-EVs) using differential centrifugation and identified by transmission electron microscopy and flow cytometry. In vitro and in vivo, both types of OM-MSC-EVs promoted the proliferation, migration, and angiogenic activities of human brain microvascular endothelial cells (HBMECs). In addition, angiogenesis-stimulatory activity in the H-EV group was significantly enhanced compared to the N-EV group. MicroRNA profiling revealed a higher abundance of miR-612 in H-EVs than in N-EVs, while miR-612 inactivation abolished the N-EV treatment benefit. To explore the roles of miR-612, overexpression and knock-down experiments were performed using a mimic and inhibitor or agomir and antagomir of miR-612. The miR-612 target genes were confirmed using the luciferase reporter assay. Gain- and loss-of-function studies allowed the validation of miR-612 (enriched in hypoxic OM-MSC-EVs) as a functional messenger that stimulates angiogenesis and represses the expression of TP53 by targeting its 3′-untranslated region. Further functional assays showed that hypoxic OM-MSC-EVs promote paracrine Hypoxia-inducible factor 1-alpha (HIF-1α)-Vascular endothelial growth factor (VEGF) signaling in HBMECs via the exosomal miR-612-TP53-HIF-1α-VEGF axis. These findings suggest that hypoxic OM-MSC-EVs may represent a promising strategy for ischemic disease by promoting angiogenesis via miR-612 transfer. Graphical Abstract

A target-guidance separation strategy composed of activity screening process with high-performance liquid chromatography and separating process with high-speed countercurrent chromatography (HSCCC)...

In this work, to further verify and develop the novel counter-current chromatography modified column separate mode, a melamine modified counter-current chromatography column was prepared. Meanwhile, the modified counter-current chromatography column was used to separate stevioside and rebaudioside A with the same partition coefficient in chosen solvent system to evaluate its separation efficiency. The results show that because of the presence of intermolecular forces between melamine and model compounds, better separation could be achieved on the modified column while it's almost impossible to be separated on the unmodified column. So the results of this research further show that column modified method is a possible approach to further increase the separation ability of counter-current chromatography. Take advantage of large sample handing capacity of counter-current chromatography, the mothed may have great potential to be an efficient method of separation and preparation enantiomer compounds.

The introduction of molecular complexity in an atom- and step-efficient manner remains an outstanding goal in modern synthetic chemistry. Artificial biosynthetic pathways are uniquely able to address this challenge by using enzymes to carry out multiple synthetic steps simultaneously or in a one-pot sequence

Cerebral ischemia/reperfusion injury causes a series of intricate cascade reactions in brain tissue causing apoptosis and proinflammatory programmed cell death known as pyroptosis of nerve cells. The dysfunction of target organelle mitochondria plays a key role in the process of neuronal apoptosis and pyroptosis. Mesenchymal stem cells (MSCs) have been widely used in the experimental or clinical treatment of various ischemic diseases, but the therapeutic efficacy of MSCs on cerebral ischemia-reperfusion injury need to be improved. We successfully cultured olfactory mucosa MSCs (OM-MSCs) to obtain a better source of seed cells. In this way, the therapeutic potential of OM-MSCs transplantation has been evaluated for ischemic stroke using an optimized culture scheme in vitro. Ischemic-hypoxic preconditioned OM-MSCs (IhOM-MSCs) were used to treat a neuron model of oxygen-glucose deprivation/reperfusion and the middle cerebral artery occlusion in rats. These results demonstrated that IhOM-MSCs mediated the upregulation of the downstream target genes GRP78 and Bcl-2 by miR-181a to protect mitochondrial function and inhibit apoptosis and pyroptosis of neurons in the ischemia/reperfusion injury model. Thus, IhOM-MSCs transplantation may be an effective therapy of ischemic stroke in the future.

Olfactory mucosa mesenchymal stem cells (OM-MSCs) have exhibited their effectiveness in central nervous system diseases and provided an appealing candidate for the treatment of ischemic stroke. Previous evidence have shown that Golgi apparatus (GA) secretory pathway Ca2+-ATPase isoform1 (SPCA1) was a potential therapeutic target for ischemic stroke. In this study, we explored the neuroprotective mechanism of OM-MSCs and its effect on the expression and function of SPCA1 during cerebral ischemia/reperfusion. Based on in vitro and in vivo experiments, we discovered that OM-MSCs attenuated apoptosis and oxidative stress in ischemic stroke models, reduced the cerebral infarction volume, and improved the neurologic deficits of rats. OM-MSCs also upregulated SPCA1 expression and alleviated Ca2+ overload and decreased the edema and dissolution of the GA in neurons. Moreover, we discovered that SPCA1 depletion in oxygen and glucose deprivation/reoxygenation (OGD/R)-treated N2a cells mitigated the protective effects of OM-MSCs. Altogether, OM-MSCs exerted neuroprotective effects in ischemic stroke probably via modulating SPCA1 and reducing the edema and dissolution of the GA in neurons.

Mesenchymal stromal cells (MSCs) have been used for the treatment of neuronal injury and neurodegenerative diseases. Their underlying mechanism may involve increased secretion of paracrine factors, which promotes tissue repair. Presently, exosomes have been regarded as important components of paracrine secretion and paracrine factors. MSC exosomes represent a promising opportunity to develop novel cell-free therapy approaches. In this study, exosomes from nasal olfactory mucosa MSCs (OM-MSCs) were extracted and purified using ultracentrifugation, resulting in exosome diameters of 40–130 nm. Similar to other exosomes, OM-MSC exosomes were CD63- and CD81-positive and calnexin-negative. Functionally, OM-MSC exosomes promoted human brain microvascular endothelial cell (HBMEC) proliferation and migration. The present study analyzed the OM-MSC exosome paracrine proteome. A total of 304 exosome-associated proteins were identified by LC–MS/MS, including plasminogen activator inhibitor 1 (SERPINE 1), insulin-like growth factor binding protein family members (IGFBP 4 and 5), epidermal growth factor receptor (EGFR), neurogenic locus notch homolog protein 2 (NOTCH 2), apolipoprotein E (APOE), and heat shock protein HSP90-beta (HSP90AB1). These molecules are known to be important in neurotrophic, angiogenesis, cell growth, differentiation, apoptosis, and inflammation and are highly correlated with the mechanism of tissue repair and neural restoration. These observations may provide a basis for further evaluation of OM-MSC exosome potential as a novel therapeutic modality.

Elution-extrusion counter current chromatography extrudes the most solute retained in the column with the highest possible peak resolution. It can greatly improve the hydrophobic window. In recent years, elution-extrusion counter current chromatography has received extensive attention in the separation of complex samples. This article first reviews the development and application of elution-extrusion counter current chromatography, including its origin, mechanism, advantages and disadvantages, and some representative applications. At the same time, this review also shared our visions and ideas on how to improve the elution-extrusion mode. This article aims to provide certain reference for the research of this technology.

An efficient combination strategy based on high-speed shear dispersing emulsifier technique and high-performance countercurrent chromatography was developed for on-line extraction and isolation of carotenoids from the fruits of Lycium barbarum. In this work, the high-speed shear dispersing emulsifier technique has been employed to extract crude extracts using the upper phase of high-performance countercurrent chromatography solvent system composed of n-hexane-dichloromethane-acetonitrile (10:4:6.5, v/v) as the extraction solvent. At the separation stage, the high-performance counter-current chromatography process adopts elution-extrusion mode and the upper phase of the solvent system as stationary phase (reverse-phase mode). As a result, three compounds including zeaxanthin, zeaxanthin monopalmitate, and zeaxanthin dipalmitate with purities of 89, 90, and 93% were successfully obtained in one extraction-separation operation within 120 min. The targeted compounds were analyzed and identified by high-performance liquid chromatography, mass spectrometry, and NMR spectroscopy. The results indicated that the present on-line combination method could serve as a simple, rapid, and effective way to achieve weak polar and unstable compounds from natural products.

The stationary phase retention is one of the most important parameters in countercurrent chromatography. In this work, a simple gradient equilibrium method was developed to further improve the stationary phase retention based on the optimized condition in the traditional equilibrium model. Meanwhile, this novel gradient equilibrium method was used to separate three flavone model compounds and compared with the conventional isocratic equilibrium method to evaluate the separation efficiency. The results show that better resolution or shorter separation time could be achieved with gradient equilibrium compared to isocratic equilibrium. So this novel equilibrium method has enormous potential for obtaining a better separation or saving the separating time in the preparative separation of target compounds.

Background : Pre-hospital emergency airway management plays an important role in pre-hospital care. Laryngeal masks are increasingly employed for the airway management of pre-hospital critical patients and have achieved promising results. Although several randomized controlled trials have reported benefits, the efficacy of laryngeal masks in pre-hospital emergency airway management compared to endotracheal intubation have not been systematically reviewed. Methods: Electronic databases (PubMed, Cochrane Library, Embase, Scopus and CNKI) were searched up to April 2019 for related randomized studies. Outcome indicators included overall intubation success rates, the success rates of the first intubation, insertion time, resuscitation efficiency rates, SpO2 rise time, the blood gas index and adverse events. Two investigators selected the trials, extracted the data according to inclusion and exclusion criteria, and assessed the quality of the literature according to the Jada score. The meta-analysis was performed using stata14.0 software. Results: We included 31 human studies. Compared to endotracheal intubation, the application of laryngeal mask for pre-hospital emergencies enhanced the resuscitation efficiency rates [RR=1.20, 95% CI (1.06, 1.35), P

While the formation of colloidal aggregates leads to artifacts in early drug discovery, their composition makes them attractive as nanoparticle formulations for targeted drug delivery as the entire nanoparticle is composed of drug. The typical transient stability of colloidal aggregates has inhibited exploiting this property. To overcome this limitation, we investigated a series of proteins to stabilize colloidal aggregates of the chemotherapeutic, fulvestrant, including the following: bovine serum albumin, a generic human immunoglobulin G, and trastuzumab, a therapeutic human epidermal growth factor receptor 2 antibody. Protein coronas reduced colloid size to

Colloidal aggregates of small molecules are the most common artifact in early drug discovery, sequestering and inhibiting target proteins without specificity. Understanding their structure and mechanism has been crucial to developing tools to control for, and occasionally even exploit, these particles. Unfortunately, their polydispersity and transient stability have prevented exploration of certain elementary properties, such as how they pack. Dye-stabilized colloidal aggregates exhibit enhanced homogeneity and stability when compared to conventional colloidal aggregates, enabling investigation of some of these properties. By small-angle X-ray scattering and multiangle light scattering, pair distance distribution functions suggest that the dye-stabilized colloids are filled, not hollow, spheres. Stability of the coformulated colloids enabled investigation of their preference for binding DNA, peptides, or folded proteins, and their ability to purify one from the other. The coformulated colloids showed little ability to bind DNA. Correspondingly, the colloids preferentially sequestered protein from even a 1600-fold excess of peptides that are themselves the result of a digest of the same protein. This may reflect the avidity advantage that a protein has in a surface-to-surface interaction with the colloids. For the first time, colloids could be shown to have preferences of up to 90-fold for particular proteins over others. Loaded onto the colloids, bound enzyme could be spun down, resuspended, and released back into buffer, regaining most of its activity. Implications of these observations for colloid mechanisms and utility will be considered.

Ting Yuan,1* Yi Zhuo,1* Chaying Su,2 Xuan Li,1 Da Duan,1 Lite Ge,1 Pei Wu,1 Hao Wang,1 Yujia Deng,1 Ming Lu1 1Department of Neurosurgery, Second Affiliated Hospital of Hunan Normal University (163 Hospital of the People’s Liberation Army), Changsha, 2Department of Pediatrics, 169 Hospital of the People’s Liberation Army, Hengyang, Peoples’ Republic ofChina * These authors contributed equally to this work Abstract: Human olfactory mucosa mesenchymal-like stem cells (hOM-MSCs) secrete paracrine factors that may exert a protective effect on the cerebral ischemia. This study was done to determine the hypoxic and ischemic effects on the mRNA and protein expression level of paracrine factors by hOM-MSCs. The hOM-MSCs were cultured with 5% or 20% serum and under either normoxic (21% O2) or hypoxic (3% O2) conditions. Expression levels of mRNA and protein for vascular endothelial growth factor (VEGF), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and matrix metalloproteinase-2 (MMP-2) were determined by quantitative reverse transcription polymerase chain reaction and Western blot, respectively. Hypoxia reduced gene expression for VEGF (5% serum), GDNF, BDNF (5% serum) and NGF (5% serum) and increased it for BDNF (20% serum), MMP-2 (5% serum) and NGF (20% serum). Ischemia lowered gene expression for VEGF (hypoxia), GDNF, BDNF (hypoxia), MMP-2 (normoxia) and NGF (hypoxia) and increased it for VEGF (normoxia), BDNF (normoxia), MMP-2 (hypoxia) and NGF (normoxia).The protein level of these factors was almost in line with the gene level. These data demonstrate that serum and oxygen levels have a significant effect on the gene and protein expression levels of paracrine factors by hOM-MSCs, which will affect how hOM-MSCs interact in vivo during cerebral ischemia. Keywords: human olfactory mucosa mesenchymal-like stem cells, paracrine factors, hypoxia, ischemia, cerebral ischemia

Transplantation of olfactory ensheathing cells (OECs) has been shown to enhance synapse formation. However, the mechanisms underlying this effect are not completely understood. We performed profiling of the OEC and astrocyte secretomes via a proteomics approach, in case hevin secreted by astrocytes might be involved in the formation of synapses. Semi-quantitative proteomic analysis revealed that 25 proteins were highly expressed, and 22 were weakly expressed in OEC conditioned medium compared with astrocyte conditioned medium. These molecules are highly associated with neural differentiation and regeneration, enzyme regulatory activity, and growth factor binding. The quantification data of clusterin, fibronectin, hevin, insulin-like growth factor binding protein 2 and secreted protein acidic and rich in cysteine were further confirmed by western blotting. Moreover, the addition of hevin in the culture medium improved neurite sprouting and outgrowth of differentiated neural stem cells. The greater expression of hevin in OEC conditioned medium than in astrocyte conditioned medium was associated with a greater capacity of synaptic formation. Thus, our results indicate that soluble factors secreted by OECs provide a permissive environment for nerve repair, and hevin is one of the key molecules facilitating neurite sprouting and outgrowth.

Countercurrent chromatography is a kind of continuous and effective liquid-liquid partition chromatography with many unique characteristics such as large load capacity, no irreversible adsorption, high recovery rate, low risk of sample denaturation and so on, which has irreplaceable advantages in the separation of proteins and peptides. This review presents the advances of several kinds of new technology of countercurrent chromatography in the separation of proteins and peptides. The development prospect of this field is also discussed.

Small molecule aggregates are considered nuisance compounds in drug discovery, but their unusual properties as colloids could be exploited to form stable vehicles to preserve protein activity. We investigated the co-aggregation of seven molecules chosen because they had been previously intensely studied as colloidal aggregators, co-formulating them with bis-azo dyes. The co-formulation reduced colloid sizes to

A combinative method using the 2,2-diphenyl-1-picrylhydrazyl (DPPH)-high performance liquid chromatography (HPLC)-diode array detector (DAD) and high-speed counter-current chromatography (HSCCC) has been developed to screen and separate radical scavengers from the water extract of Cynomorium songaricum Rupr. Under the target guidance of the DPPH-HPLC-DAD experiment, 3 compounds were found to possess potential antioxidant activities. In order to identify the chemical structures of those compounds, the HSCCC method with a two-phase solvent system composed of ethyl acetate–water (1 : 1; v/v) was developed to isolate and purify the active compounds. Three compounds, 14.3 ± 0.7 mg of (+)-catechin (1), 15.2 ± 0.6 mg of (−)-epicatechin (2) and 11.3 ± 0.4 mg oleuropein (3) were obtained from 600 mg of crude sample with purities of 97.8%, 98.3% and 95.6%, respectively, as determined by HPLC. Their structures were elucidated by electrospray ionization-mass spectrometry (ESI-MS), 1H nuclear magnetic resonance (NMR) and 13C NMR. Among them, oleuropein was obtained from C. songaricum for the first time. The peak order of the three compounds in the HSCCC chromatogram was completely different from that in the HPLC chromatogram. Even both HSCCC and HPLC methods that are employed in this paper were in reversed phase mode. The elution order of HSCCC was determined by the hydrophobicity of the compounds, while the elution order of HPLC may be affected by some other interactions between the stationary phase and the compounds such as hydrogen bonding and steric effects. In addition, antioxidant activities of the three compounds were evaluated by the methods of DPPH radical scavenging assay. All of them showed high radical scavenging activities with the EC50 values being 16.97 ± 0.02, 11.15 ± 0.09 and 41.32 ± 0.20 μg mL−1 for (+)-catechin, (−)-epicatechin and oleuropein, respectively.

Nasal olfactory mucosa mesenchymal stem cells (OM-MSCs) have the ability to promote regeneration in the nervous systemin vivo. Moreover, with view to the potential for clinical application, OM-MSCs have the advantage of being easily accessible from patients and transplantable in an autologous manner, thus eliminating immune rejection and contentious ethical issues. So far, most studies have been focused on the role of OM-MSCs in central nervous system replacement. However, the secreted proteomics of OM-MSCs have not been reported yet. Here, proteins secreted by OM-MSCs cultured in serum-free conditions were separated on SDS-PAGE and identified by LC-MS/MS. As a result, a total of 274 secreted proteins were identified. These molecules are known to be important in neurotrophy, angiogenesis, cell growth, differentiation, and apoptosis, and inflammation which were highly correlated with the repair of central nervous system. The proteomic profiling of the OM-MSCs secretome might provide new insights into their nature in the neural recovery. However, proteomic analysis for clinical biomarkers of OM-MSCs needs to be further studied.

Antioxidants play an essential role in human health, as they have been found to be capable of lowering the incidence of many diseases, such as cancer and angiocardiopathy. Currently, more attention is paid to natural antioxidants because of the possible insecurity of synthetic antioxidants. Thus, the development of efficient techniques or methods to separate antioxidants from natural sources is requested urgently. High-speed counter current chromatography (HSCCC) is a unique support-free liquid-liquid chromatographic technique and has been widely applied in the field of separation of natural products. In this review, we summarize and analyze the related researches on the application of HSCCC in the separation of various natural antioxidants so far. The purpose of the article is to provide a certain theoretical support for the separation of natural antioxidants by HSCCC, and to make full use of advantages of HSCCC in the separation of bioactive components. In particular, some key problems associated with the separation strategies, the structural categories of natural antioxidants, solvent system choices, and the application of different elution modes in HSCCC separation, are summarized and commented. We expect that the content reviewed can offer more evidence for the development of the field of natural antioxidants separation, so as to achieve large-scale preparation of natural antioxidants.

For the shortcomings of large overshoot and poor anti-disturbance ability when using the traditional PID control, ADRC control algorithm that is a nonlinear state error feedback control algorithm has been proposed in the sophisticated control system of static reactive power generator. The simulation results show that the algorithm can make the system reactive power compensation more quickly and more effectively, therefore the control strategy is feasible.

On 21 July 2012, a huge thunderstorm hit Beijing, prompting the city government to act immediately to deal with the emergency. Yet great losses were caused, exposing problems about urban flood control and drainage, and making people take a new look at them. It is not uncommon for a rainfall of such a degree to happen in Asia. Comparatively speaking, however, unlike in Beijing, fewer damages are caused in Taiwan, Japan and the Philippines given the same situation. In this article, therefore, the problems arising after a heavy rainfall and their solutions will be discussed.

Aim To investigate whether the human olfactory mucosa mesenchymal stem cells (OM-MSCs) can differentiate into photoreceptor cells in vitro. Methods Through the olfactory mucosa adherent method, olfactory mucosa was isolated, cultured and identified in vitro among mesenchymal stem cells. The cell surface markers were analyzed by flow cytometry, induced to differentiate into retinal photoreceptor cells in vitro, and the expression of rhodopsin was observed and identified by Immunofluorescence and Western blot methods. Results OM-MSCs from human were spindle cell-based, and showing radial colony arrangement. OM-MSCs were negative for CD34, CD45 and CD105, but positive for CD73 and CD90. Following induction, a strong positive reaction was produced by photoreceptor specific marker rhodopsin in the cells. Conslusion This novel finding demonstrates that OM-MSCs can be cultured and expanded in vitro. They possess biological characteristics of mesenchymal stem cells, and have the ability to be induced into retinal cells.

To explore whether hypoxic condition could promote the olfactory mucosa mesenchymal stem cells (OM-MSCs) to differentiate into neurons with the olfactory ensheathing cells (OECs) supernatant and the potential mechanisms. Methods: The OM-MSCs and OECs were isolated and cultured, and they were identified by flow cytometry and immunofluorescence. The OM-MSCs were divided into three groups: a 3%O2+ HIF-1α inhibitors (lificiguat: YC-1) + OECs supernatant group (Group A) , a 3%O2 + OECs supernatant group (Group B) and a 21%O2 + OECs supernatant group (Control group). The neurons, which were differentiated from OM-MSCs, were assessed by immunofluorescence test. The mRNA and protein expression of hypoxia-inducible factor-1α (HIF-1α), βIII-tubulin and glial fibrillary acidic portein (GFAP) were detected by quantitative polymerase chain reaction (Q-PCR) and Western blot. The potassium channels were analyzed by patch clamp. Results: The neurons differentiated from OM-MSCs expressed the most amount of βIII-tubulin, and the result of Q-PCR showed that HIF-1α expression in the Group B was significantly higher than that in the other groups (all P0.05). Western blot result showed that the βIII-tubulin protein expression was significantly higher and GFAP protein expression was obviously decreased in the Group B (both P0.05). The patch clamp test confirmed that the potassium channels in the neurons were activated. Conclusion: Hypoxic condition can significantly increase the neuronal differentiation of OM-MSCs by the OECs supernatant and decrease the production of neuroglia cells, which is associated with the activation of HIF-1 signal pathway.目的：研究低氧微环境下利用嗅鞘细胞(olfactory ensheathing cells，OECs)上清液诱导嗅黏膜间充质干细胞(olfactory mucosa mesenchymal stem cells，OM-MSCs)更多地向神经元分化及其相关的机制。方法：分离培养OECs和OM-MSCs，应用流式细胞仪和免疫荧光方法分别进行鉴定；实验将OM-MSCs分为3%O2+低氧诱导因子-1α(hypoxia-inducible factor-1α，HIF-1α)抑制剂利非西呱(lificiguat，YC-1)+OECs上清诱导组(A组)、3%O2+OECs上清诱导组(B组)及21%O2+OECs上清诱导组(对照组)。采用免疫荧光检测分化后的神经元，采用定量聚合酶链反应(quantitative polymerase chain reaction，Q-PCR)和Western印迹分别检测HIF-1α的mRNA及 βIII-微管蛋白(βIII-tubulin)、胶质纤维酸性蛋白(glial fibrillary acidic portein，GFAP)的表达，再用膜片钳检测分化后的神经元钾离子通道开放情况。结果：实验各组相比较，B组OM-MSCs诱导后免疫荧光显示βIII-tubulin表达最多，Q-PCR显示B组HIF-1α表达明显增高(均P0.05)；Western 印迹表明B组中βIII-tubulin蛋白表达显著增多，而胶质细胞标志物GFAP表达明显降低(均P0.05)；且诱导分化后的神经元经膜片钳检测发现钾离子电流。结论：低氧微环境下的OM-MSCs经OECs上清液诱导能显著提高其向神经元分化的比例，并明显降低了神经胶质细胞的产生，且与细胞HIF-1α信号通路被激活有关。.

In recent years, improved three-ratio is an effective method for transformer fault diagnosis based on Dissolved Gas Analysis (DGA). In this paper, diagonal recurrent neural network (DRNN) is used to resolve the online fault diagnosis problems for oil-filled power transformer based on DGA. To overcome disadvantages of BP algorithm, a new recursive prediction error algorithm (RPE) is used in this paper.In addition, to demonstrate the effectiveness and veracity of the proposed method, some cases are used in the simulation. The simulation results are satisfactory.

The paper describes the main factors of influencing increase cropper electrolysis current density.The main circuit and the control circuit of cycle reverse rectification power for copper electrolysis are designed. The simulation and practical results show the cycle reverse electrolysis power based active disturbance rejection controller has high reliability and precision of steady current and anti-disturbance,the density of electrolysis current can be increased and anode passivation can be decreased ，the effect is better especially for high impurities of anode sheets. the energy-saving and lower costs and high quality and increase of output are achieved. this technology is practicable.

Urotensin II (UII) is a cyclic peptide that was originally extracted from the caudal neurosecretory system (CNSS) of fish. UII is well known to exhibit cardiovascular, ventilatory, and motor effects in vertebrates. Studies have reported that UII exerts mitogenic effects and can act as an autocrine/paracrine growth factor in mammals. However, similar information in fish is limited. In this study, the full-length cDNAs of UII and its receptor (UT) were cloned and characterized in the orange-spotted grouper. UII and UT were expressed ubiquitously in various tissues in grouper, and particularly high levels were observed in the CNSS, CNS, and ovary. A functional study showed that UT was coupled with intracellular Ca2+ mobilization in HEK293 cells. Studies carried out using i.p. injections of UII in grouper showed the following: i) in the hypothalamus, UII can significantly stimulate the mRNA expression of ghrh and simultaneously inhibit the mRNA expression of somatostatin 1 (ss1) and ss2 3 h after injection; ii) in the pituitary, UII also significantly induced the mRNA expression of gh 6 and 12 h after injection; and iii) in the liver, the mRNA expression levels of ghr1/ghr2 and igf1/igf2 were markedly increased 12 and 3 h after the i.p. injection of UII respectively. These results collectively indicate that the UII/UT system may play a role in the promotion of the growth of the orange-spotted grouper.

In recent years, improved three-ratio is an effective method for transformer fault diagnosis based on Dissolved Gas Analysis (DGA). In this paper, a simple dynamic neural network named as diagonal recurrent neural network (DRNN) is used to resolve the online fault diagnosis problems for oil-filled power transformer based on DGA. Because of the characteristic of improved three-ratio boundary is lack of matching, fuzzy logic in fault diagnosis is presented also to deal with the data of the neural network inputs. DRNN is used to model the fault diagnosis structure, the fuzzy logic is used to improve the faults diagnose reliability. In addition, some cases are used to show the capability of the suggested method in oil-filled power transformers fault diagnosis.

A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control A magnetic suspension linear feed device has been introduced in this paper, it is consist of linear motion and suspension parts. The mathematical model of suspension system is modeled. Aiming at the suspension part which is an nonlinear and strong coupling system, the auto-disturbance rejection controller (ADRC) is used. The inner disturbance and outside disturbance is observed and compensated, the result of simulation indicates the suspension control has better dynamic, static and robust characters by using the auto-disturbance rejection controller.

The principle, ideas, procedures and optimization problems of the filtering algorithm were presented in the article. First, the filtering algorithm procedures of aerial image based on stochastic resonance theory was introduced, then the curve of noise strength and peak signal to noise ratio (PSNR) was analyzed, a golden-section fast search algorithm was proposed and discussed as well to find out the maximum point of PSNR in the process of filtering. Experimental results indicate that the filtering method in this article is superior to other methods on high noise strength aerial image, and the stability and robustness are better than other methods . The multiples of filtering image’s PSNR is 1.2~1.4 times than other methods.

Lactamases are bacterial enzymes conferring resistance to ?-lactam antibiotics in clinically-relevant pathogens, and represent relevant drug targets. Recently, the identification of new boronic acids (i.e. RPX7009) paved the way to the clinical application of these molecules as potential drugs. Here, we screened in silico a library of ~1400 boronic acids as potential AmpC ?-lactamase inhibitors. Six of the most promising candidates were evaluated in biochemical assays leading to the identification of potent inhibitors of clinically-relevant ?-lactamases like AmpC, KPC-2 and CTX-M-15. One of the selected compounds showed nanomolar K i value with the clinically-relevant KPC-2 carbapenemase, while another one exhibited broad spectrum inhibition, being also active on Enterobacter AmpC and the OXA-48 class D carbapenemase.

Kar3 kinesins are microtubule (MT) minus-end-directed motors with pleiotropic functions in mitotic spindle formation and nuclear movement in budding and fission yeasts. A Kar3-like kinesin is also expressed by the filamentous fungus Ashbya gossypi, which exhibits different nuclear movement challenges from its yeast relatives. Presented here is a 2.35 Å crystal structure and enzymatic analysis of the AgKar3 motor domain (AgKar3MD). Compared to the previously published Saccharomyces cerevisiae Kar3MD structure (ScKar3MD), AgKar3MD displays differences in the conformation of some of its nucleotide-binding motifs and peripheral elements. Unlike ScKar3MD, the salt bridge between Switch I and Switch II in AgKar3MD is broken. Most of the Switch I, and the adjoining region of helix α3, are also disordered instead of bending into the active site cleft as is observed in ScKar3MD. These aspects of AgKar3MD are highly reminiscent of the ScKar3 R598A mutant that disrupts the Switch I-Switch II salt bridge and impairs MT-stimulated ATPase activity of the motor. Subtle differences in the disposition of secondary structure elements in the small lobe (β1a, β1b, and β1c) at the edge of the MD are also apparent even though it contains approximately the same number of residues as ScKar3. These differences may reflect the unique enzymatic properties we measured for this motor, which include a lower MT-stimulated ATPase rate relative to ScKar3, or they could relate to its interactions with different regulatory companion proteins than its budding yeast counterpart.

A new sliding mode controller for trajectory tracking of ball and plate system is proposed. In the controller, a nonlinear observer which is independent on plant model is used to observer the uncertainties and disturbance of the system. This paper proved that the nonlinear observer is convergence by properly selecting the parameters of observer. Sliding mode controller based on nonlinear observer is designed for the ball and plate system and it can guarantee stabilization of closed-loop system. The results of simulation and experiments indicate that the proposed nonlinear observer can observer uncertainties and disturbance of system, the proposed sliding mode control method is effectively to solve the problems of trajectory tracking in the nonlinear ,uncertain system.

Neural stem cell (NSC) transplantation is an effective method of giving a supplement of cells lost and promoting functional recovery after spinal cord injury (SCI). Nonetheless, owing to hostile environments at the injury site, such as ischaemic hypoxia conditions and inflammatory cytokines, poor cell survival and uncontrolled differentiation are consistent problems encountered following NSC transplantation in ischaemic neural tissue. Hypoxia-inducible factor-1a (HIF-1α) provides profound protection to NSCs against negative factors at the injury site. On the other hand, HIF-1 can induce NSCs to differentiate into neurons. We predict that transplanted NSCs modified by an HIF-1α gene would have a better efficacy for promoting neural regeneration and functional reconstruction.

Morphine is an alkaloid from the opium poppy used to treat pain. The potentially lethal side effects of morphine and related opioids-which include fatal respiratory depression-are thought to be mediated by μ-opioid-receptor (μOR) signalling through the β-arrestin pathway or by actions at other receptors. Conversely, G-protein μOR signalling is thought to confer analgesia. Here we computationally dock over 3 million molecules against the μOR structure and identify new scaffolds unrelated to known opioids. Structure-based optimization yields PZM21-a potent Gi activator with exceptional selectivity for μOR and minimal β-arrestin-2 recruitment. Unlike morphine, PZM21 is more efficacious for the affective component of analgesia versus the reflexive component and is devoid of both respiratory depression and morphine-like reinforcing activity in mice at equi-analgesic doses. PZM21 thus serves as both a probe to disentangle μOR signalling and a therapeutic lead that is devoid of many of the side effects of current opioids.

Colloidal aggregation of organic molecules is the dominant mechanism for artifactual inhibition of proteins, and controls against it are widely deployed. Notwithstanding an increasingly detailed understanding of this phenomenon, a method to reliably predict aggregation has remained elusive. Correspondingly, active molecules that act via aggregation continue to be found in early discovery campaigns and remain common in the literature. Over the past decade, over 12 thousand aggregating organic molecules have been identified, potentially enabling a precedent-based approach to match known aggregators with new molecules that may be expected to aggregate and lead to artifacts. We investigate an approach that uses lipophilicity, affinity, and similarity to known aggregators to advise on the likelihood that a candidate compound is an aggregator. In prospective experimental testing, five of seven new molecules with Tanimoto coefficients (Tc's) between 0.95 and 0.99 to known aggregators aggregated at relevant concentrations. Ten of 19 with Tc's between 0.94 and 0.90 and three of seven with Tc's between 0.89 and 0.85 also aggregated. Another three of the predicted compounds aggregated at higher concentrations. This method finds that 61 827 or 5.1% of the ligands acting in the 0.1 to 10 μM range in the medicinal chemistry literature are at least 85% similar to a known aggregator with these physical properties and may aggregate at relevant concentrations. Intriguingly, only 0.73% of all drug-like commercially available compounds resemble the known aggregators, suggesting that colloidal aggregators are enriched in the literature. As a percentage of the literature, aggregator-like compounds have increased 9-fold since 1995, partly reflecting the advent of high-throughput and virtual screens against molecular targets. Emerging from this study is an aggregator advisor database and tool ( http://advisor.bkslab.org ), free to the community, that may help distinguish between fruitful and artifactual screening hits acting by this mechanism.

To improve the separation capability of CCC, a novel solid-liquid two-stationary phases CCC (ASP-CCC) column was prepared employing graphene oxide (GO) conjugated poly-dopamine (PD) coating (GO/PD) as auxiliary stationary phase (ASP). The results of Scanning electron microscopy (SEM), contact angle and X-ray photoelectron spectroscopy (XPS) indicated that nanostructured GO and PD were successfully grafted on the inner wall of the PTFE column. Three alkaloid compounds were selected as the target analytes to evaluate the performance of the novel column. Because of the intermolecular force (hydrogen bond, electrostatic interaction and π-π interaction) between the ASP and model compounds, three analytes were well separated with this novel ASP-CCC column. Additionally, the novel column exhibited higher stationary phase retention ratio, about 8%, than original column without changing the chromatographic condition. Furthermore, the eluotropic sequence of analytes on novel column was in accordance with that in the original column. This suggested that the novel column is a CCC column with auxiliary stationary phase (ASP) in its own right, and the present separation mode is the combination of partition chromatography and adsorption chromatography.

Traditional Chinese Medicines (TCMs) have been the sole source of therapeutics in China for two millennia. In recent drug discovery efforts, purified components of TCM formulations have shown activity in many in vitro assays, raising concerns of promiscuity. Here, we investigated 14 bioactive small molecules isolated from TCMs for colloidal aggregation. At concentrations commonly used in cell-based or biochemical assay conditions, eight of these compounds formed particles detectable by dynamic light scattering and showed detergent-reversible inhibition against β-lactamase and malate dehydrogenase, two counter-screening enzymes. When three of these compounds were tested against their literature-reported molecular targets, they showed similar reversal of their inhibitory activity in the presence of detergent. For three of the most potent aggregators, contributions to promiscuity via oxidative cycling were investigated; addition of 1 mM DTT had no effect on their activity, which is inconsistent with an oxidative mechanism. TCMs are often active at micromolar concentrations; this study suggests that care must be taken to control for artifactual activity when seeking their primary targets. Implications for the formulation of these molecules are considered.