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Sweroside, as one of the main components of Swertia L. in Gentianaceae, has the effect of clearing heat and detoxifying. In previous studies, sweroside has been reported to have anti-inflammatory effect on LPS-induced inflammation by alleviating NF-κB signaling pathway. In this paper, we investigate the anti-inflammatory effects of sweroside by establishing LPS-induced acute lung injury (ALI) model in mice. Experimental results showed that sweroside could reduce the wet-to-dry ratio of the lung and inhibit MPO activity. In addition, it turned out that sweroside reduced pathological changes in lung tissue and the numbers of inflammatory cells. Moreover, sweroside significantly reduced the levels of inflammatory cytokines and down-regulated the NF-κB signaling pathway. And the results demonstrated that sweroside could increase the expression of SIRT1, and the protective effects of sweroside on LPS-induced ALI were reversed by SIRT1 inhibitor EX-527. In conclusion, sweroside can protect LPS-induced ALI mice through inhibiting inflammation. [ABSTRACT FROM AUTHOR]

O-GalNAc glycans (or mucin O-glycans) play pivotal roles in diverse biological and pathological processes, including tumor growth and progression. Structurally defined O-GalNAc glycans are essential for functional studies but synthetic challenges and their inherent structural diversity and complexity have limited access to these compounds. Herein, we report an efficient and robust chemoenzymatic modular assembly (CEMA) strategy to construct structurally diverse O-GalNAc glycans. The key to this strategy is the convergent assembly of O-GalNAc cores 1–4 and 6 from three chemical building blocks, followed by enzymatic diversification of the cores by 13 well-tailored enzyme modules. A total of 83 O-GalNAc glycans presenting various natural glycan epitopes are obtained and used to generate a unique synthetic mucin O-glycan microarray. Binding specificities of glycan-binding proteins (GBPs) including plant lectins and selected anti-glycan antibodies towards these O-GalNAc glycans are revealed by this microarray, promoting their applicability in functional O-glycomics. Serum samples from colorectal cancer patients and healthy controls are assayed using the array reveal higher bindings towards less common cores 3, 4, and 6 than abundant cores 1 and 2, providing insights into O-GalNAc glycan structure-activity relationships. O-GalNAc glycans are essential in many biological and pathological processes, but difficult to access due to their structural complexity and synthetic challenges. Here, the authors report an efficient chemoenzymatic modular assembly strategy to construct structurally diverse O-GalNAc glycans, use the synthesised glycans to generate a synthetic mucin O-glycan microarray and profile binding specificities of glycan-binding proteins. [ABSTRACT FROM AUTHOR]

The core component of the fracturing and completion integral string is the setting and anchoring system, which mainly includes upper and lower permanent slips. Reasonable structural optimization design can reduce the damage of downhole string components and improve the adaptability of completion string in complex reservoir. In order to optimize the structural design of completion string and improve the reliability of anchoring setting, the influence of shape and bearing capacity on slip structure of permanent packer was considered by using nonlinear finite element numerical analysis method. On this basis, the optimized results of the permanent slips were tested by the anchoring and setting experiments of the loading pressure inside the string. The results showed that the optimized permanent slip had the advantages of low fracture strength, supplementary fracture setting performance and high reliability compared with the conventional permanent slip structure. The optimized permanent slip structure plays an important role in improving the reliability of the completion string, which is of great significance to improve the formation adaptability of the whole fracturing completion string and the effective development of tight sandstone gas reservoirs. [ABSTRACT FROM AUTHOR]

Mitochondrial damage, characterized by altered morphological distribution and the damage of cristae, is closely associated with mitochondrial disease. However, imaging methods for capturing mitochondrial morphology at the nanoscale level in live samples remain unavailable, which seriously hinders the accurate evaluation and diagnosis of mitochondrial-related diseases. In response, we propose a super-resolution quantification strategy based on structured illumination microscopy (SIM) for the rapid, accurate evaluation of mitochondrial morphology. Using the strategy, we accurately captured the morphological distribution of mitochondria at the nanoscale level in a way generally applicable to checking various cell processes and identifying patients with mitochondrial disease who exhibit the SLC25A46 mutation. We also used algorithm-assisted super-resolution imaging to quantitatively analyze damage to mitochondrial cristae, which supports a novel drug screening strategy—high-resolution drug screening—for investigating drugs' pharmacodynamics on organelles in living cells. In short, our strategy improves the accurate examination of changes in mitochondrial morphology in living cells and indicates new ways in which SIM-imaging can assist in diagnosing mitochondrial disease at the single-cell level. [ABSTRACT FROM AUTHOR]

In the past decades, the roles of carbohydrates in living organisms and their potential use in many fields have been extensively investigated. Sialyl Lewis x (sLex), a member of body carbohydrate, is an inherent blood-type tetrasaccharide on the surface of different cells, the lymphocyte, neutrophil, some T cells, multiple tumor cells and so on. SLex is a common ligand of the three selectins, L-selectin, E-selectin and P-selectin, and plays important roles in multiple physiological phenomenas by interacting with selectins. Under normal physiological conditions, sLex can affect the immune process and fertilization process. Lower expression of sLex could cause leukocyte adhesion defects (LAD) II. Overexpression of sLex on the other hand has been linked to several cancers including melanoma, breast, pancreatic, liver, lung, head and neck, ovarian, bladder carcinomas and some blood disease including Hodgkin disease, some B cell chronic lymphocytic leukemias, acute lymphoblastic leukemias, and most acute nonlymphocytic leukemias. This paper mainly reviews the physiological functions and pathological effects of sLex and its applications in disease diagnosis, drug delivery, gene transfer and medical molecular imaging. We aim to help researchers and other readers quickly grasp the physiological and pathological roles and its medical applications of sLex, and give some suggestions for research directions. [ABSTRACT FROM AUTHOR]

In this study, the effects of porosity of the fore-catalytic bed and after-catalytic bed and preheat temperature on the decomposition and combustion characteristics of a 5 N ammonium dinitramide (ADN)-based thruster were numerically investigated in terms of the distribution of components, temperature, and pressure. The results indicated that the porosity of the fore-catalytic bed and preheating temperature significantly affected the decomposition and combustion characteristics. The porosity of the fore-catalytic bed was optimized, and the thrust performance was demonstrated to improve with increasing of porosity of the after-catalytic bed and pre-heating temperature. The results were favorable for the investigation of decomposition and combustion characteristics and could also be beneficial to the design and manufacture of different types of ADN-based thrusters. [ABSTRACT FROM AUTHOR]

We have recently derived a β-N-acetylhexosaminidase, BbhI, from Bifidobacterium bifidum JCM 1254, which could regioselectively synthesize GlcNAcβ1-3Galβ1-4Glc with a yield of 44.9%. Here, directed evolution of BbhI by domain-targeted mutagenesis was carried out. Firstly, the GH20 domain was selected for random mutagenesis using MEGAWHOP method and a small library of 1300 clones was created. A total of 734 colonies with reduced hydrolytic activity were isolated, and three mutants with elevated transglycosylation yields, GlcNAcβ1-3Galβ1-4Glc yields of 68.5%, 74.7%, and 81.1%, respectively, were obtained. Subsequently, nineteen independent mutants were constructed according to all the mutation sites in these three mutants. After transglycosylation analysis, Asp714 and Trp773 were identified as key residues for improvement in transglycosylation ability and were chosen for the second round of directed evolution by site-saturation mutagenesis. Two most efficient mutants D714T and W773R that acted as trans-β-N-acetylhexosaminidase were finally achieved. D714T with the substitution at the putative nucleophile assistant residue Asp714 by threonine showed high yield of 84.7% with unobserved hydrolysis towards transglycosylation product. W773R with arginine substitution at Trp773 residue locating at the entrance of catalytic cavity led to the yield up to 81.8%. The kcat/Km values of D714T and W773R for hydrolysis of pNP-β-GlcNAc displayed drastic decreases. NMR investigation of protein–substrate interaction revealed an invariable mode of the catalytic cavity of D714T, W773R, and WT BbhI. The collective motions of protein model showed the mutations Thr714 and Arg773 exerted little effect on the dynamics of the inside but a large effect on the dynamics of the outside of catalytic cavity. [ABSTRACT FROM AUTHOR]

As the core component of the fracturing tool, the packer cartridge plays a vital role in a horizontal well stimulation and transformation process (Sun and Bai in Pet Explor Dev 44:1022–1029, 2017). Influenced by many factors such as formation workflow, borehole structure and construction conditions, the mechanical response of the packer rubber cylinder in sealing is complex and changeable (Jun et al. in J Pet Sci Eng 171:495–506, 2018; Tong et al. J Pet Sci Eng 172:964–975, 2019; Zhu et al. J Pet Sci Eng 151:311–317, 2017b). In order to study the mechanical response mechanism of the packer tool under complex working conditions, tensile tests of rubber under the corrosion environment of carbon dioxide formation fluid were carried out and the constitutive material parameters of Yeoh model after corrosion were obtained. The results showed that the tensile strength of hydrogenated nitrile butadiene rubber (HNBR) decreased by 7.86–17.01% after corrosion in simulated formation fluid, and the elongation at break increased by 2.09–19.74%. Compared with AFLAS (tetrapropyl fluoro elastomer), HNBR rubber had better stability and can be used as the preferred material for the service environment of permanent packers. Based on the mechanical properties of numerical calculation results before and after corrosion, it was found that the contact pressure and compression distance of the whole HNBR packer changed slightly, which met the requirements of field construction. On the basis of optimum selection of rubber material, the sealing performance of packer in borehole casing with enlargement/reduction caused by formation is analyzed. The results show that the casing with expansion deformation will lead to setting lag or lax, and the shrinkage casing will lead to setting advance or even stress failure. The analysis results provide theoretical support for the improvement in permanent packer string and its adaptation to complex formation. [ABSTRACT FROM AUTHOR]

Technology advances in genomics, proteomics, and metabolomics largely expanded the pool of potential therapeutic targets. Compared with the in vitro setting, cell-based screening assays have been playing a key role in the processes of drug discovery and development. Besides the commonly used strategies based on colorimetric and cell viability, we reason that methods that capture the dynamic cellular events will facilitate optimal hit identification with high sensitivity and specificity. Herein, we propose a live-cell screening strategy using structured illumination microscopy (SIM) combined with an automated cell colocalization analysis software, Cellprofiler™, to screen and discover drugs for mitochondria and lysosomes interaction at a nanoscale resolution in living cells. This strategy quantitatively benchmarks the mitochondria-lysosome interactions such as mitochondria and lysosomes contact (MLC) and mitophagy. The automatic quantitative analysis also resolves fine changes of the mitochondria-lysosome interaction in response to genetic and pharmacological interventions. Super-resolution live-cell imaging on the basis of quantitative analysis opens up new avenues for drug screening and development by targeting dynamic organelle interactions at the nanoscale resolution, which could facilitate optimal hit identification and potentially shorten the cycle of drug discovery. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the applicability of high-performance liquid chromatography with diode-array detection (HPLC–DAD) combined with electrospray ionization tandem mass spectrometry (ESI–MS) for the simultaneous screening and determination of tetracycline antibiotic analogues illegally adulterated in herbal preparations was investigated. The HPLC–DAD method could be employed to separate and simultaneously determine eight tetracyclines using an isocratic solvent system. These tetracycline antibiotics include doxycycline, 6-epidoxycycline and tetracycline, which are difficult to identify because they are structural isomers. ESI–MS was used in combination with HPLC–DAD to improve the qualitative accuracy in this study. Method validation included the investigation of linearity, selectivity, stability, limits of detection and quantitation, trueness, precision and ruggedness. The response exhibited a good linear relationship with the analyte concentration. The coefficient of determination (r2) was greater than 0.9993. The limits of quantification for the examined tetracycline antibiotics ranged from 1.11 to 25.73 µg·mL−1, and the recoveries ranged from 91.0 to 104.0%. The proposed methods were specific, sensitive and accurate, and they could be promising and powerful tools for the routine screening of tetracycline analogues in herbal medicines to ensure food safety and public health.Graphical abstract: [ABSTRACT FROM AUTHOR]

A reliable and cost-efficient protein synthesis system is the prerequisite for both structural and functional proteomic studies. The last decades saw the great technological improvement in the development of different protein synthesis systems. The cell-free protein synthesis system, especially Escherichia coli-based cell-free protein synthesis system, has emerged as one of the most robust protocols which can meet the growing demand of protein synthesis. E. coli-based cell-free protein synthesis system has become a more complete system for protein synthesis over the last two decades. Here, we review the main development and modifications of the E. coli-based cell-free protein synthesis system. [ABSTRACT FROM AUTHOR]

Purpose: To synthesize and evaluate the antitumor efficacy of double-targeted docetaxel (DTX)-carboxymethyl chitosan (CMCS)-PEG-NGR (DTX-CPN) conjugates that could target to CD13 over-expressed tumor neovascular endothelium cells and tumor cells. Methods: DTX was conjugated to CMCS via biodegradable linker and cNGR was applied to endow the conjugates with double targeting ability. The physiochemical properties and stability of this DTX-CPN conjugates were characterized. Cellular uptake study was carried out to evaluate the targeting ability of DTX-CPN conjugates. Cytotoxicity and apoptosis analysis were conducted to evaluate in vitro antitumor effects. In vivo antitumor efficacy was investigated in B16 murine melanoma model. Results: DTX-CPN conjugates could self-assemble into nanoparticles in water and were stable in plasma. cNGR modification could promote the cellular uptake of DTX-CPN conjugates in CD13 positive HUVEC and B16 cells, leading to more significant cytotoxicity and apoptosis effect than non-targeted conjugates. DTX-CPN conjugates also exhibited better antitumor effect than non-targeted conjugates and Duopafei® in a B16 murine melanoma model. Conclusions: Double-targeted DTX-CPN conjugates could efficiently target to tumor neovascular cells and tumor cells, and achieve good antitumor effects. DTX-CPN conjugates may be promising candidate for one-double targeting cancer therapy. [ABSTRACT FROM AUTHOR]

Canonical correlation analysis (CCA) is a well-known technique for extracting linearly correlated features from multiple views (i.e., sets of features) of data. Recently, a locality-preserving CCA, named LPCCA, has been developed to incorporate the neighborhood information into CCA. Although LPCCA is proved to be better in revealing the intrinsic data structure than CCA, its discriminative power for subsequent classification is low on high-dimensional data sets such as face databases. In this paper, we propose an alternative formulation for integrating the neighborhood information into CCA and derive a new locality-preserving CCA algorithm called ALPCCA, which can better discover the local manifold structure of data and further enhance the discriminative power for high-dimensional classification. The experimental results on both synthetic and real-world data sets including multiple feature data set and face databases validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The availability of uridine 5′-diphosphate N-acetylglucosamine (UDP-GlcNAc) is a prerequisite for the GlcNAc-transferase-catalyzed glycosylation reaction. UDP-GlcNAc has already been synthesized using an N-acetylhexosamine 1-kinase (NahK) and a GlcNAc-1-P uridyltransferase (truncated GlmU) and here, a fusion enzyme was constructed with truncated GlmU and NahK. After determination of the optimum catalytic condition (pH 8.0 at 40 °C), the fusion enzyme was used to synthesize UDP-GlcNAc in a single step with a yield of 88 % from GlcNAc, ATP and UTP. Furthermore, a simplified purification method was demonstrated using separation by gel filtration after by-product digestion with alkaline phosphatase. An overall yield of 77 % and a purity of over 90 % were achieved. [ABSTRACT FROM AUTHOR]

Thymopentin plays an important role in improving imbalanced immune systems of patients, however, it has a limited half-life in plasma. To get more stable and active thymopentin analogs, a fusion thymosin α1-thymopentin (Tα1-TP5) gene was synthesized and cloned into vector pGAPZαA. Tα1-TP5 fusion peptide was expressed in pichia pastoris and purified by metal chelating chromatography and gel filtration chromatography. The circular dichroism spectra (CD) indicated that the secondary structure of Tα1-TP5 fusion peptide is dominated by a-helix and random coil. In vitro analysis showed that the plasma half-life of Tα1-TP5 fusion peptide is 140 ± 14 min, which is longer than that of TP5 (5.6±0.7 min) and Tα1 (127±11 min). The in vitro activity assay presented that Tα1-TP5 fusion peptide has greater activity in promoting proliferation of Kunming mouse splenocytes, and in vivo experiment it showed better activity in promoting the phagocytosis of macrophages and secretion of IL-2 than both Tα1 and TP5. Our findings suggest that Tα1-TP5 fusion peptide might be a potential therapeutic agent. [ABSTRACT FROM AUTHOR]