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Structure–property relationships over highly-uniform, isolated MIL-100(Cr) nodes are investigated. Brønsted acid-mediated dehydration of methanol is used as a probe reaction to decipher acid site properties, and the data point to the prevalence of an associative mechanism.

Cross-linking mass spectrometry methods have not been successfully applied to protein-protein interaction discovery at a proteome-wide level mainly due to the computation complexity (O (n2)) issue. In a previous report, we proposed a decision tree searching strategy (DTSS), which can reduce complexity by orders of magnitude. In this study, we further found that the monolinked peptides carry out the information on the retention time of the corresponding cross-linked pairs; therefore, the retention time of cross-linked peptide pairs can be predicted accurately. By utilizing the retention time as an extra filter, the false positive rate can be reduced by around 86% with a sensitivity loss of 10%. The method combined with DTSS (T-DTSS) not only benefits improving identification confidence but also leads to lower cutoff scores and facilitates substantially increasing inter-cross-link identification. T-DTSS was successfully applied to the identification of inter-cross-links obtained from Escherichia coli cell lysate cross-linked by a newly synthesized enrichable cross-linker, pDSBE. The approach can be applicable to both cleavable and noncleavable methods.

Edwardsiella piscicida (E. piscicida) is a common pathogen in freshwater and marine environments and an important intestinal pathogen of fish. Fucose large presence in the intestines could possibly regulate relevant genes to promote bacterial infectivity. In this study, the wild-type E. piscicida and the fucP gene-deleted strain ΔfucP were used to identify its virulence-regulating pathway and colonization. The results showed that the gene transcription levels of key FusKR and type III secretion system (T3SS) in E. piscicida were upregulated by different concentrations of fucose. Both the wild-type and the ΔfucP strain grew faster with 30 mM fucose added than that without fucose added. In addition, the penetration of the wild-type E. piscicida with fucose added was significantly stronger than that of both ΔfucP with fucose and the wild-type E. piscicida without fucose. Meanwhile, the gene transcription levels of T3SS-related genes eseB, eseC, eseD, eseE, and eseG in E. piscicida were significantly downregulated after the fucP gene mutant. Finally, tilapia infected with the wild-type strain showed a significant increase in the E. piscicida colonization compared to those infected with the mutant strain. All results indicate that FucP of E. piscicida mediated fucose to promote the growth, motility, and intestinal colonization in tilapia.

Edwardsiella piscicida (E. piscicida) is an important fish pathogen. However, the mechanism of Glu6P transport regulatory protein UhpA how to affect the virulence gene expression in E. piscicida is still unclear. The results in this study showed that the metabolism-related gene expression of cysteine synthase (orf 1134) and sulphate transporter (ychM) in the uhpA mutant strain ΔuhpA was 0.76-fold and 0.68-fold lower than the ones in the wild strains (p < .05). The gene expression of ethA and ethB in the ΔuhpA strain was 0.80-fold and 0.72-fold lower than the ones in the wild strains (p < .05). However, the gene expression of fliC and flgN in the ΔuhpA was 1.51-fold and 1.21-fold higher than the ones in the wild strains (p < .05). The gene expression of T3SS (esrB and esrC) and T6SS (evpB and evpC) in the ΔuhpA was 1.27-fold, 1.13-fold, 1.28-fold and 1.23-fold higher than the ones in the wild strains (p < .05). This suggested that the uhpA gene could regulate the key virulence gene expression, and the uhpA gene was associated with the pathogenicity of E. piscicida in fish.

Edwardsiella piscicida (E. piscicida) is an important zoonotic pathogen that infects fish by colonizing the intestines. The intestine provides nutrition including Glucose 6-phosphate (Glu6P) and a competitive environment for the microbiota. Although the transport system regulatory protein gene uhpA has been reported in E. piscicida genomes, whether the uhpA gene is involved in the pathogenicity of E. piscicida remains largely unknown. Therefore, the uhpA gene mutants strain E. piscicida ΔuhpA was constructed to elucidate the functions of Glu6P and the uhpA gene in E. piscicida. The results demonstrated that Glu6P significantly increased the gene expression of uhpC/uhpB/uhpA than without adding Glu6P in the culture. The gene expression of uhpC and uhpB was down regulated in the mutant strain than that of in the wild type strain. E. piscicida ΔuhpA exhibited an increase in virulence compared to that of E. piscicida EIB202 [LD50 value: (3.98 × 106 CFU/fish) and LD50 value: (1.45 × 107 CFU/fish) respectively]. Besides, although TNF-α did not show significant differences (p > 0.05) in the spleen of tilapia infected with ΔuhpA and EIB202 in the whole observed period, the gene expression of IL-1β and TGF-β in the spleen of tilapia infected with ΔuhpA showed significantly higher (p

Polyurethane mixture, made of waste rubber particle, aggregate, and polyurethane adhesive, has low raveling resistance which affects the durability of the mixture. The objective of this study is to enhance the raveling resistance of polyurethane mixture. The content of polyol in the hydroxyl component was determined by Fourier transform infrared spectroscopy. The suitable curing conditions for polyurethane adhesive to enhance the raveling resistance were selected by the orthogonal experiment and mechanical tests. The relationship of the raveling resistance with crosslink density and elastic modulus was tested and calculated through the wear test. The results showed that when the ratios of the isocyanate component to the hydroxyl component were 1:3.2, 1:6.3, and 1:9.5, respectively, the isocyanate component was excessive. The ranking of the significance of the influence factors, from high to low, was first the curing temperature, then curing time, and finally the blending ratio; within the ranges of blending ratio, curing temperature, and curing time selected in this study, the appropriate blending ratio was 10:2, and the curing time was 6 h. For the polyurethane mixture involved in this study to obtain high raveling resistance, if a crosslinking agent or a new polyurethane adhesive is added, the tensile strength and tensile elastic modulus should be in the range of 3.02 to 3.27 MPa and 5.50 to 6.02 MPa, respectively; when using the FS2 polyurethane adhesive directly, the suitable curing conditions for the mixture are 90 °C and 6 h or 80 °C and 6 h. The results from this study could be beneficial for obtaining a high raveling resistance for the polyurethane mixture.

Edwardsiella piscicida (E. piscicida) is an important zoonotic pathogen that mostly infects fish by colonizing the intestine. Fucose within the intestine could regulate the pathogenicity of some intestinal pathogens. Here we identified the function of fucose permease in E. piscicida and its physiological influence. The results showed that E. piscicida grew faster in the presence of l -fucose. The fucose permease gene fucP mutant strain ΔfucP significantly decreased penetration and motility in mucin compared with the wild-type strain. The gene expression levels of esaB, esaD, esaL and esaK in ΔfucP had significantly downregulated when compared with the wild-type strain. Most importantly, the survival rate of zebrafish after being infected with ΔfucP was significantly higher than those of the wild type. In a word, fucose promoted the growth and motility of E. piscicida and the fucP gene mutant decreased the pathogenicity of E. piscicida in zebrafish.

Poroelastic road surface is a type of pavement surface which makes full use of waste rubber and at the same time effectively reduces traffic noise. However, the comprehensive performance of polyurethane rubber particle mixture (PRPM) prepared with different kinds of rubber particles and polyurethane is rarely studied. This study aims to evaluate the comprehensive performance of PRPMs, such as the high-temperature performance, anti-aging performance, skid resistance performance, etc. Rubber particles and four different kinds of polyurethane were adopted to prepare polyurethane rubber particle mixtures. A dog bone shape mold for forming specimens was self-designed, and a slab specimen forming device was created to form slab specimens. Different test methods were conducted to evaluate the comprehensive performance of the mixtures. The results showed that four types of polyurethane rubber particle mixtures exhibited high rutting resistance and high temperature performance. Mixture F5 had the best anti-aging performance and noise reduction performance. The skid-resistance of the polyurethane rubber particle mixture was slightly lower than that of conventional asphalt mixture, but it still met the road specification requirements. The polyurethane rubber particle mixture had more interconnected pores, which was found to have greater drainage function and was expected to reduce noise. Polyurethane rubber particle mixture F5 had superior comprehensive performance, except for slightly lower skid resistance, and it was determined to be the most suitable polyurethane rubber particle mixture type for future application.

Paocai as a traditional side dish in Asia gains its popularity owing to the favorable tastes, which are bestowed by microbial metabolisms. The microorganisms involved in fermentation are mainly lactic acid bacteria and Saccharomyces, while low-quality Paocai may contain spoilage and potentially pathogenic microorganisms such as Escherichia coli. To monitor and control food safety for direct vat inoculation of Paocai, this study intended to develop propidium monoazide based quantitative PCR to enumerate fermentation starter Lactobacillus plantarum NCU116, as well as Saccharomyces and potentially present pathogenic bacteria. Universal and specific primers targeting different microorganisms were designed to identify and quantify total lactic acid bacteria, Lactobacillus plantarum, Saccharomyces, and Escherichia coli by establishment of standard curves, respectively. Plate counting was performed and showed comparable results to quantitative PCR analysis, indicating the applicability and efficiency of absolute quantitative PCR in fast detection of microbial composition in Paocai system. Nitrite as a hazardous substance in Paocai was also investigated by spectrophotometry and reverse transcription quantitative PCR. The mechanism of nitrite synthesis and degradation was studied, revealing nitrite reductase in lactic acid bacteria as an effective enzyme in reducing nitrite present in the fermented vegetable.

LuxS/AI-2 is an important quorum sensing system which affects the growth, biofilm formation, virulence, and metabolism of bacteria. LuxS is encoded by the luxS gene, but how this gene is associated with a diverse array of physiological activities in Edwardsiella piscicida (E. piscicida) is not known. Here, we constructed an luxS gene mutant strain, the △luxS strain, to identify how LuxS/AI-2 affects pathogenicity. The results showed that LuxS was not found in the luxS gene mutant strain, and this gene deletion decreased E. piscicida growth compared to that of the wild-type strain. Meanwhile, the wild-type strain significantly increased penetration and motility in mucin compared to levels with the △luxS strain. The 50% lethal dose (LD(50)) of the E. piscicida △luxS strain for zebrafish was significantly higher than that of the wild-type strain, which suggested that the luxS gene deletion could attenuate the strain’s virulence. The AI-2 activities of EIB202 were 56-fold higher than those in the △luxS strain, suggesting that the luxS gene promotes AI-2 production. Transcriptome results demonstrated that between cells infected with the △luxS strain and those infected with the wild-type strain 46 genes were significantly differentially regulated, which included 34 upregulated genes and 12 downregulated genes. Among these genes, the largest number were closely related to cell immunity and signaling systems. In addition, the biofilm formation ability of EIB202 was significantly higher than that of the △luxS strain. The supernatant of EIB202 increased the biofilm formation ability of the △luxS strain, which suggested that the luxS gene and its product LuxS enhanced biofilm formation in E. piscicida. All results indicate that the LuxS/AI-2 quorum sensing system in E. piscicida promotes its pathogenicity through increasing a diverse array of physiological activities.

Edwardsiella piscicida (E. piscicida) is an important zoonotic pathogen, which infects animals by colonizing the intestine. Glucose 6-phosphate (Glu6P) was an important carbohydrate in intestine and could be used as a regulate signal. Here we identify a virulence-regulating pathway named Glu6P transport regulatory protein UhpA, which affects the virulent genes of hemolysins, flagellar, T3SS, T6SS and metabolism related genes how to promote E. piscicida infect the host. The results showed that the metabolism related gene expression of cysteine synthase (orf 1134) and sulfate transporter (ychM) in the uhpA mutant strain ΔuhpA was 0.76-fold and 0.68-fold lower than the ones in the wild strains (P < 0.05), the gene expression of ethA and ethB in the ΔuhpA strain was 0.80-fold and 0.72-fold lower than the ones in the wild strains (P < 0.05). However, the gene expression of fliC and flgN in the ΔuhpA was 1.51-fold and 1.21-fold higher than the ones in the wild strains (P < 0.05), the gene expression of T3SS (esrB and esrC) and T6SS (evpB and evpC) in the ΔuhpA was 1.27-fold, 1.13-fold 1.28-fold and 1.23-fold higher than the ones in the wild strains (P < 0.05). Besides, the survival rate of fish challenged with E. piscicida EIB202 and ΔuhpA was 50% and 30% respectively. These suggested that although the uhpA gene deletion decreased the metabolic level and the hemolysins related gene expression in E. piscicida, the uhpA gene could down regulate the key virulent gene expression to decrease the pathogenicity of E. piscicida in fish.

Edwardsiella piscicida (E. piscicida) is a significant bacterial pathogen of cultured fish, which infected fish meanly through the intestine. Glucose 6-phosphate (Glu6P) in the intestine is nutritious to the pathogen, Meanwhile, Glu6P was found using as a virulent regulating signal for bacteria. The UhpA, one of the Glu6P transport system regulatory proteins could down-regulate the uhpC/uhpB/uhpA system and decrease its pathogenicity. However, the motility and the colonization of E. piscicida affected by UhpA were still unclear. In this study, the motility and the colonization of E. piscicida were monitored. The result demonstrated that the motility of EIB202 was significantly stronger than that of in ΔuhpA according to fractions 4, 8 and 9. However, the motility of ΔuhpA was significantly stronger than that of EIB202 according to the total number at the whole experiment. Although, there was no difference in the number of bacteria in the posterior intestine of tilapia after infected with E. piscicida EIB202 and ΔuhpA. The number of bacteria in the anterior and the middle intestine of fish infected with ΔuhpA were significantly higher than that of in fish infected with EIB202 at the whole experiment (P

A number of vinylsulfonamides were synthesized and screened to identify reagents that can be used to modify octreotide under biological pH and room temperature with improved efficiency. N-Phenyl-N-aceto-vinylsulfonamide exhibits higher reactivity and has emerged as an efficient reagent that has the ability to realize the selective modification of peptides and proteins at the N-terminus via aza-Michael addition. We showed that, after conjugation of peptides and proteins with the reagent containing a bioorthogonal functional group, the derivatives could be further labelled by functionalities, including fluorescent tags, modified drugs and polyethylene glycol (PEG) polymers without the need for prior treatment. Somatostatin, lysozyme, and RNaseA were selectively modified at the N-terminus, which illustrated the application of the method.

Antibody-drug conjugates (ADCs) have emerging as efficient agents to target deliver cytotoxic drugs and reduce their off-target side effects. Triptolide has attracted attention to be used in ADC development. Herein, three rationally designed triptolide drug-linkers have been synthesized for use in site-specific construction of ADCs. Carbamates that were supposed to be more stable than carbonates were introduced to attach triptolide to the linkers. PEG and discrete PEG chains were incorporated to improve the hydrophilicity of drug-linkers. The ADCs were finally site-specifically prepared by conjugation of the drug-linkers to trastuzumab through disulfide re-bridging approach. The preliminary anti-tumor activities of these ADCs were evaluated and they displayed high potencies against HER2-targeted cancer in vitro and in vivo.

A series of vinylsulfonamides were synthesized and screened for site-selective modification of the ε-amino group of lysine-bearing free α-amine residues. N-Methyl-N-phenylethenesulfonamide has emerged as an applicable reagent and has been developed for efficient and highly selective modification of the lysine residue of native peptides in the presence of a free N-terminus via aza-Michael addition. We demonstrated that functional N-phenylvinylsulfonamide derivatives with a fluorescent moiety or drug could also be conjugated to the lysine residue of octreotide and insulin with high specificity, without modifying the N-terminus. Our method provides a promising strategy for site-selective lysine functionalization in native peptides with a free N-terminus.

A novel water soluble, phosphate-based enrichable, retro-Michael addition-driven MS-cleavable and multi-targeting cross-linker was developed., Chemical cross-linking mass spectrometry (XL-MS) is a powerful technology for obtaining protein structural information and studying protein–protein interactions. We report phospho-bisvinylsulfone (pBVS) as a novel water-soluble, MS-cleavable, phosphate-based enrichable and multi-targeting cross-linker. In this approach, the fragmentation of pBVS cross-linked peptides occurs in situ through retro-Michael addition. The phosphate group is successfully used as a small affinity tag to isolate cross-linked peptides from the highly abundant non-cross-linked peptides. In addition, the linker targets multiple types of amino acid residues, including cysteine, lysine and histidine. This method was applied to cross-link bovine serum albumin (BSA), myoglobin and Lbcpf1 demonstrating the ability to yield accurate and abundant information to facilitate protein structure elucidation.

A number of novel sterol derivatives with dipeptide-like side chains were synthesized using an Ugi four-component condensation method and assayed to test their anti-inflammatory effects in activated microglial cells. Compound 18b ((3S,10R,13S)-N-((R)-1-(tert-butylamino)-1-oxo-3-phenylpropan-2-yl)-3-hydroxy-N,10,13-trimethyl-2,3,4,7,8,9,10,11,12,13,14,15-dodecahydro-1H-cyclopenta[a]phenanthrene-17-carboxamide) was identified as the most potent anti-inflammatory agent in the series of compounds analyzed. Compound 18b markedly inhibited the expression of proinflammatory factors, including inducible nitric oxide synthase, interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and cyclooxygenase-2 in lipopolysaccharide-stimulated microglial cells. Further studies showed that compound 18b significantly suppressed the transcriptional activity of AP-1 and NF-κB in activated microglial cells, which was likely mediated by the inhibition of the p38 MAPK and JNK signal transduction pathways. In addition, compound 18b displayed neuroprotective effects in a microglial-conditioned medium/neuron coculture and an experimental focal ischemic mouse model.

A new crystal of Yb-doped gadolinium niobate, 5 at.% Yb:GdNbO 4 , is grown by Czochralski method for the first time. The structure of Yb:GdNbO 4 is determined by Rietveld refinement to the X-ray powder diffraction data and it belongs to the monoclinic space group of I 2/a . With the center of 955 nm, the FWHM of absorption spectra is 57 nm and the absorption cross section is calculated to be 0.97 × 10 −20 cm 2 . Spectral parameters are calculated with absorption spectrum. In emission spectra, the strongest peak is at 1001 nm and the FWHM is 49 nm. In comparison with corresponding emission cross section of Yb:YSO and Yb:GSO, Yb:GdNbO 4 exhibits a relatively larger emission cross section. In addition, a maximal output power of 270 mW is obtained and the slope efficiency is 7.5%.

A new class of N-phenyl-divinylsulfonamides which can be easily prepared have been successfully developed and utilized as efficient linkers in the field of disulfide bond modification. Functional divinylsulfonamides provide opportunities for the specific introduction of various functionalities, including affinity probes, fluorescent tags, and drugs, into peptides.

A new Cr,Yb,Ho,Eu:YAlO3(YAP) laser crystal was successfully grown by the Czochralski method. Thermal properties were investigated along the a, b, and c crystalline axes. Results indicate that the Cr,Yb,Ho,Eu:YAP crystal has large anisotropic thermal expansion and that the suitable crystal growth direction is the b axis. The Debye temperatures were fitted, and the lattice vibration frequencies were calculated. Spectroscopic measurements show that Cr3+ and Yb3+ can be used as sensitizers of Ho3+ ions, and Eu3+ ions can play a role of the deactivator in decreasing the lifetime of laser lower level 5I7 from 8.69 ms to 1.89 ms, which is beneficial in decreasing laser threshold and increasing laser conversion efficiency. All these findings suggest that the Cr,Yb,Ho,Eu:YAP crystal is a new potential candidate for realizing 2.8–3 μm laser output pumped by a 970 nm laser diode or pulsed flash lamp.

We demonstrate a 968 nm diode end-pumped Er:GYSGG (Gd1.17Y1.83Sc2Ga3O12) laser at 2.796 μm operated in the pulse and continuous-wave (CW) modes. A maximum laser energy of 2.43 mJ is obtained at a pulse width of 2 ms, corresponding to a peak power of 1.25 W and a slope efficiency of 7.2%. In the CW mode, the maximum output power is 348 mW, corresponding to an optical–optical conversion efficiency of 9.2% and a slope efficiency of 10.1%. The M2 factor is 1.94, and the beam divergence is 6.4 mrad. Gamma irradiation at 100 Mrad only slightly affects laser output performance. This result suggests that Er:GYSGG crystal is a potentially new mid-infrared radiation-resistant laser material that can be applied in space and ionizing radiation environment.

The Nd3+-doped Bi4Ge3O12 (BGO) single-crystal fiber (SCF) was successfully grown by the micro-pulling-down method with the resistance heating system. The fluorescence spectrum and transmission spectrum of the Nd:BGO SCF were measured. Excited by a continuous-wave 808-nm laser diode, a fluorescence peak around 1064 nm was observed. At an absorbed pump power of 15.25 W, the Nd:BGO SCF laser delivered a power of 3.37 W with a slope efficiency of 31.2%.

A picosecond (ps) mid-infrared (MIR) optical parametric amplifier (OPA) with LiInSe2 crystal was demonstrated for the first time. The MIR OPA was pumped by a 30 ps 1064 nm Nd:YAG laser and injected by a barium boron oxide (BBO)-based widely tunable near-infrared seed. A maximum idler pulse energy of 433 μJ at 4 μm has been obtained under a pump energy of 17 mJ, and the corresponding pulse duration was estimated to be ~13 ps. To our knowledge, this is the highest single pulse energy generated by LiInSe2 crystal. Furthermore, an idler spectrum tuning from 3.6 to 4.8 μm was investigated at fixed pump energy of 15 mJ.

We demonstrate a comparative investigation on Er,Pr:GYSGG and GYSGG/Er,Pr:GYSGG composite crystals at 2.79 μm. Simulating results show the highest temperatures are 369 K and 318 K, respectively. A maximum output power of 825 mW with slope efficiency of 19.2% and maximum laser energy of 3.65 mJ with slope efficiency of 22.7% are obtained in the GYSGG/Er,Pr:GYSGG composite crystal, which have an obvious improvement than those of Er,Pr:GYSGG crystal. The thermal focal lengths are respectively 41 and 62 mm when the pump power is 2.5 W. All these results indicate that the GYSGG/Er,Pr:GYSGG composite crystal has great advantages in reducing the influence of thermal effects and improving laser performances.

We demonstrate a 968 nm diode end-pumped Er,Pr:GYSGG (Gd₁.₁₇Y₁.₈₃Sc₂Ga₃O₁₂) laser at 2.79 μm operated in the pulse and continuous-wave (CW) modes. The lifetimes for the upper laser level ⁴I₁₁/ ₂ and lower level ⁴I₁₃/₂ are 0.52 and 0.60 ms, respectively. The laser produces 284 mW of power in the CW mode, corresponding to the optical-to-optical efficiency of 14.8% and slope efficiency of 17.4%. The maximum laser energy achieved is 2.4 mJ at a repetition rate of 50 Hz and pulse duration of 0.5 ms, corresponding to a peak power of 4.8 W and slope efficiency of 18.3%. These results suggest that doping deactivator Pr3+ ions can effectively decrease the lower-level lifetime and improve the laser efficiency.