Search

Tuberculosis is a chronic infectious disease, caused by Mycobacterium tuberculosis, that seriously endangers human health. Skeletal tuberculosis is the most common type of extrapulmonary tuberculosis and tuberculous arthritis is the second most common type of skeletal tuberculosis. We report a case series of patients with tuberculous arthritis, two of whom had no joint disease in the past and presented as monoarthritis. The final patient had a history of rheumatoid arthritis, with polyarthritis that was aggravated during treatment with glucocorticoids and immunosuppressive drugs. This series of cases can contribute to early diagnosis and treatment with appropriate infection control measures.

Ultra-high nickel material is considered to be a promising cathode material. However, with the increase of nickel content, the interfacial side reactions between the cathode and electrolyte become increasingly serious. Herein, an atomically controllable ionic conductor Li3PO4(LPO) coating is deposited on the LiNi0.90Co0.06Mn0.04O2(NCM9064) based electrode by the atomic layer deposition method. The results shows that the LPO coating is uniformly and densely covered on the surface of secondary particles of NCM9064, helping to prevent the direct contact between the electrolyte and cathode during the charging-discharging process. In addition, the coating layer is electrochemically stable. As a result, the interfacial side reactions during the long cycle are effectively suppressed, and the solid electrolyte interphase layer at the interface is stabilized. The electrode with 20 layers of LPO deposition (ALD-LPO-20) exhibits an excellent capacity retention of 81% after 200 cycles in 2.8-4.3 V at 25 °C, which is 18% higher than the unmodified material (ALD-LPO-0). Besides, the moderate LPO coating improves the rate capability and high temperature cycling performance of NCM9064. This study provides a method for the modification of ultra-high nickel cathode materials and corresponding electrodes.

ABSTRACTInteraction between humans and the gut microbiota is important for human physiology. Here, the gut microbiota was analyzed via metagenomic sequencing, and the fluctuations in the gut microbiota under the conditions of spaceflight were characterized. The composition and function of the gut microbiota were substantially affected by spaceflight; however, individual specificity was uncompromised. We further confirmed the species fluctuations and functional genes from both missions. Resistance and virulence genes in the gut microbiota were affected by spaceflight, but the species attributions remained stable. Spaceflight markedly affected the composition and function of the human gut microbiota, implying that the human gut microbiota is sensitive to spaceflight.

Transarterial chemoembolization (TACE) and percutaneous microwave coagulation therapy (PMCT) are commonly used to treat intrahepatic recurrent liver cancers. However, there is no information regarding their effectiveness in patients with recurrent intrahepatic cholangiocarcinoma (ICC) after resection.

LiNiO2(LNO) is one of the most promising cathode materials for lithium-ion batteries. Tungsten element in enhancing the stability of LNO has been researched extensively. However, the understanding of the specific doping process and existing form of W is still not perfect. This study proposes a lithium-induced grain boundary phase W doping mechanism. The results demonstrate that the introduced W atoms first react with the lithium source to generate a Li-W-O phase at the grain boundary of primary particles. With the increase of lithium ratio, W atoms gradually diffuse from the grain boundary phase to the interior layered structure to achieve W doping. The feasibility of grain boundary phase doping is verified by first principles calculation. Furthermore, it is found that the Li2WO4grain boundary phase is an excellent lithium ion conductor, which can protect the cathode surface and improve the rate performance. The doped W can alleviate the harmful H2↔H3 phase transition, thereby inhibiting the generation of microcracks, and improving the electrochemical performance. Consequently, the 0.3wt% W-doped sample provides a significant improved capacity retention of 88.5% compared with the pristine LNO (80.7%) after 100 cycles at 2.8-4.3 V under 1 C.

The matching of poly(ethylene oxide) (PEO)-based electrolytes with ultrahigh-nickel cathode materials is crucial for designing new-generation high-energy-density solid-state lithium metal batteries (SLMBs), but it is limited by serious interfacial side reactions between PEO and ultrahigh-nickel materials. Here, a high-concentration electrolyte (HCE) interface with a customized Li+solvation sheath is constructed between the cathode and the electrolyte. It induces the formation of an anion-regulated robust cathode/electrolyte interface (CEI), reduces the unstable free-state solvent, and finally achieves the compatibility of PEO-based electrolytes with ultrahigh-nickel cathode materials. Meanwhile, the corrosion of the Al current collector caused by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) ions is prevented by lithium difluoro(oxalato)borate (LiDFOB) ions. The synergistic effect of the double lithium salt is achieved by a well-tailored ratio of TFSI–and DFOB–in the first solvation sheath of Li+. Compared with reported PEO-based SLMBs matched with ultrahigh-nickel (Ni ≥ 90%) cathodes, the SLMB in this work delivers a high discharge specific capacity of 216.4 mAh g–1(0.1C) even at room temperature. This work points out a direction to optimize the cathode/electrolyte interface.

The effect of synergistic action of ultrasonic vibration and solidification pressure on tensile properties of vacuum counter-pressure casting ZL114A alloys was studied systemically through testing and analyzing the tensile strength and elongation subjected to different ultrasonic powers and solidification pressures. The results indicate that the synergistic action of ultrasonic vibration and solidification pressure can result in the refinement of grains and improvement of tensile properties. Both the highest tensile strength and elongation of aluminum alloy were obtained under synergistic action of 600 W ultrasonic power and 350 kPa solidification pressure. Moreover, the tensile fracture morphology shows obvious ductile fracture characteristics. When the solidification pressure is lower than 300 kPa, the effect of ultrasonic power on tensile strength and elongation is more obvious, but when the solidification pressure is higher than 300 kPa, the effect of solidification pressure on tensile strength and elongation is greater. Meanwhile, the size and morphology of the eutectic silicon were improved significantly by the ultrasonic vibration and pressurized solidification. The strip and massive eutectic silicon phase are completely converted into small short rod-like and evenly distributed Si phases at the grain boundary of primary α-Al.

An organocatalytic [4 + 1] cyclization of o-QMs with MBH carbonates has been established using naphthylindole-derived phosphine (NIP) as an organocatalyst. By using this approach, a series of 2,3-dihydrobenzofuran derivatives have been synthesized in high yields and excellent diastereoselectivities (up to 99% yield, >95:5 dr). This reaction not only has established the first [4 + 1] cyclization of o-QMs with MBH carbonates but also represents the first application of naphthylindole-derived phosphines as organocatalysts in catalytic reactions. In addition, this reaction has also provided a useful method for constructing 2,3-dihydrobenzofuran scaffolds.

ABSTRACTβ-N-acetylhexosaminidases (EC3.2.1.52), which belong to the glycosyl hydrolase family GH20, are important enzymes for oligosaccharides modification. Numerous microbial β-N-acetylhexosaminidases have been investigated for applications in biology, biomedicine and biotechnology. Akkermansia muciniphilais an anaerobic intestinal commensal bacterium which possesses specific β-N-acetylhexosaminidases for gut mucosal layer colonization and mucin degradation. In this study, we assessed the in vitro mucin glycan cleavage activity of the A. muciniphilaβ-N-acetylhexosaminidase Am2136 and demonstrated its ability that hydrolyzing the β-linkages joining N-acetylglucosamine to a wide variety of aglycone residues, which indicated that Am2136 may be a generalist β-N-acetylhexosaminidase. Structural and enzyme activity assay experiments allowed us to probe the essential function of the inter-domain interactions in β23-β33. Importantly, we revealed that the hydrolysis activity of Am2136 was enhanced by nucleotides. We further speculated that this activation mechanism might be associated with the conformational motions between domain III and IV. To our knowledge, this is the first report of nucleotide effector regulated β-N-acetylhexosaminidase, to reveal its novel biological functions. These findings contribute to understanding the distinct properties within the GH20 family and lay a certain foundation to develop controllable glycan hydrolyzing catalysts.Abbreviations: OD600 - optical cell densities at 600 nm; LB - Luria–Bertani; IPTG - isopropyl β-D-1-thiogalactopyranoside; PMSF - phenylmethanesulfonyl fluoride; rmsd - root mean square deviation; GlcNAc - N-acetyl-β-D-glucosamine; GalNAc - N-acetyl-β-D-galactosamine; Gal - galactose

A novel alternating polymer, ProDOT-TPE, with aggregation-enhanced fluorescent emission and electrochromic properties based on thiophene and tetraphenylethene derivatives was designed, synthesized, and characterized. The polymer displays weak photoluminescence in tetrahydrofuran, but its corresponding film prepared by spray-coating exhibits yellow-green fluorescent light at 540 nm. The color of the polymer film could be switched from bright yellow to navy blue by applying a relatively low voltage. An electrochromic device (ECD) of the polymer was fabricated that differs from common ECDs because both its color and fluorescent state could be synchronously switched by an applied voltage, making the polymer a unique candidate for electrochemical fluorescence and electrochromic applications.

In contrast to the surging need for the cobalt-free nickel-rich layered transition metal oxide cathodes in lithium-ion batteries, the chemical and structural change in the solid-state synthesis of such materials is still not clear enough. Herein, the solid-state synthetic process of LiNi0.94Mn0.04Al0.02O2from room temperature to excessive temperature is systematically studied to present a detailed and full view of the structure transformation, valence variation, and impurity phase generation alongside the synthetic process. The results indicate three stages of the synthetic process, that is the decomposition-chemical combination stage below 500 °C, the regularization of R3¯m phase stage at 500∼800 °C, and the excessive calcining stage above 800 °C. Surprisingly, during the first stage below 500 °C, the precursor and alkali lithium start to react at a much lower temperature (e.g., 300 °C) than expected, accompanied by the integration of a considerable amount of Li element into the bulk of precursor and the oxidization of Ni. Specifically, the stoichiometric ratio of Li/TM in LixTMO2is 37%, 55%, and ∼100% at 300, 400, and 500 °C, together with more than half of Ni oxidized to +3. However, on the third stage above 800 °C, R3¯m phase in LixTMO2will become unstable and lead to the emergence of NiO-like rock-salt, accompanied by the reduction of a portion of Ni3+and significant Li loss. The stoichiometric ratio of Li/TM in LixTMO2is 79% at 1000 °C. These findings provide an insight into the solid-state synthesis of cobalt-free nickel-rich layered transition metal oxide cathodes.

The dynamic recrystallization (DRX) behavior of as-extruded 3Cr20Ni10W2 heat-resistant alloy was investigated by hot compressions with a fixed height reduction of 60% over a temperature range from 1,203 to 1,403 K and a strain rate range from 0.01 to 10 s−1. Results show that DRX occurs more easily at lower temperatures and higher strain rates, the stress level increases significantly with the increase of deformation temperature or the decrease of strain rate. Under such wide range of deformation conditions the flow stress evolution generally indicates two characteristics: work hardening (WH) followed by DRX, or by dynamic recovery (DRV). The variation of the average size of grains refined by DRX behavior in the alloy is characterized by linking the deformation conditions during hot compression process. At a fixed temperature, the average grain size linearly decreases with increasing strain rate in log scale. At a lower strain rate, the average grain size rapidly increases with increasing temperature, while it remains almost constant at strain rate of 10 s−1. At a higher strain rate, grain size data sets tend to be closer to the average size value, which indicates that as strain rate increases, the microstructures become more and more uniform. The effects of the temperatures and strain rates on the average grain size can be represented by Zener–Hollomon parameter, Z, and the relationships between the average grain size and Zparameter can be described as a nonlinear equation, which indicates that the average grain size decreases with increasing Zparameter. On the plot of average grain size DA$${D_A}$$–lnZ$${\rm{ln}}\,Z$$, the regions corresponding to DRV (lnZ≤77.9$${\rm{ln}}\ Z\,\le \,77.9$$) and DRX (lnZ>77.9$${\rm{ln}}\ Z\,\gt \,77.9$$) were clarified clearly.

Aiming at the phenomenon that our country has a large number of disabled due to illness or accident while the corresponding assistive devices is extremely deficient, we have designed a kind of mechanical arm which is intended to be equipped on wheelchair. We adopt articulated mechanical arm with multi-DOF as its mechanical structure, and choose MCU as the main controller; therefore it can make all kinds of flexible action to achieve a variety of functions. In order to improve the accuracy of manipulator, based on experimental results, we optimize the mechanical arm’s structure, improving its strength and stiffness; in order to realize the motion control of the manipulator, the kinematics analysis is conducted, when solving the mechanical arm’s anthropomorphic action problem, we set key points and then optimize the trajectory with linear interpolation, at last achieve anthropomorphic movement.

Through the environmental pulsating measure in a 1.5 MW wind generator tower drum in Inner Mongolia wind farm , modeling and modal analysis of tower drum are finished with the ANSYS finite element software, and compared with the field measured results, the difference is in the allowed ranged. Proper interval exists between numerical simulation and data obtained from the wind generator tower drum inherent frequencies and blade rotation excitation frequency , which meets the standard design requirements of《Wind power generation unit tower》.

In Escherichia coli, four gene products(selA, selB, selCand selD)and a selenocysteine(Sec) insertion sequence( SECIS) are required for the correct translation of UGA codons encoding Sec. Previous studies have shown that the stoichiometry of selenoproteine mRNA and elongation factor SelB affect the efficiency of Sec incorporation. Herein lies a detailed analysis of the effects of co-expressing selA, selBand selCgenes under inducible promoters on the incorporation efficiency of Sec. Over-expression of either selAor selBreduced the efficiency of Sec incorporation by 61.1% or 11.6%, respectively, compared to the over-expression of the reporter vector alone did. Concomitant over-expression of selCwith selAor selBcompletely reversed the reduce of the efficiency of Sec but still reduced the efficiency of the incorporation relative to that observed for expression of selCalone. Over-expression of selCgene alone under L-arabinose induction reduced the efficiency of the incorporation relative to that observed for co-expressing selCwith selAand selBunder the control of its endogenous promoter in the absence of L-arabinose. Co-expression of selA, selBand selCwith selAor selBunder the control of inducible promoters increased the efficiency of Sec incorporation by 69.7%. Moreover, inducing selenoprotein-related gene expression during the late exponential phase increased the efficiency of Sec incorporation by a factor of 5.4 relative to that observed for the reporter vector alone. These results suggest that the co-expression of selA, selBand selCin Escherichia coliunder the control of inducible promoters is a viable and promising strategy for increasing the yields of selenoproteins.

The investigation was concentrated on the through-thickness properties of thick-composite laminates, and the development of a novel test method and several specimens with two different shapes and three to four different sizes. The experiments were performed on thick composite specimens; and all through-thickness mechanical properties under compressive and tensile loading with their corresponding failure mechanisms were determined. Overall, the configuration of specimens and test method in this paper are efficient in obtaining the through-thickness properties of thick-composite laminates.

To elucidate the relationships between molecular recognition and catalytic ability, we chose three assay systems using three different thiol substrates, glutathione (GSH), 3‐carboxyl‐4‐nitrobenzenethiol (CNBSH), and 4‐nitrobenzenethiol (NBSH), to investigate the glutathione peroxidase (GPx) activities of 2,2′‐ditellurobis(2‐deoxy‐β‐cyclodextrin) (2‐TeCD) in the presence of a variety of structurally distinct hydroperoxides (ROOH), H2O2, tert‐butyl peroxide (tBuOOH), and cumene peroxide (CuOOH), as the oxidative reagent. A comparative study of the three assay systems revealed that the cyclodextrin moiety of the GPx mimic 2‐TeCD endows the molecule with selectivity for ROOH and thiol substrates, and hydrophobic interactions are the most important driving forces in 2‐TeCD complexation. Furthermore, in the novel NBSH assay system, 2‐TeCD can catalyze the reduction of ROOH about 3.4×105times more efficiently than diphenyl diselenide (PhSeSePh), and its second‐order rate constants for thiol are similar to some of those of native GPx. This comparative study confirms that efficient binding of the substrate is essential for the catalytic ability of the GPx mimic, and that NBSH is the preferred thiol substrate of 2‐TeCD among the chosen thiol substrates. Importantly, the proposed mode of action of 2‐TeCD imitates the role played by several possible noncovalent interactions between enzymes and substrates in influencing catalysis and binding.

The free radicals generated from the iron containing system of xanthine oxidase and hypoxanthine (Fe‐XO/HX) were directly detected by using spin trapping. It was found that not only superoxide anion (O2−) and hydroxyl radical (OH), but also alkyl or alkoxyl radicals (R) were formed when saccharides such as glucose, fructose and sucrose were added into the Fe‐XO/HX system. The generated amount of R was dependent on the kind and concentration of saccharides added into the Fe‐XO/HX system and no R were detected in the absence of saccharides, indicating that there is an interaction between the saccharide molecules and the free radicals generated from the Fe‐XO/HX system and saccharide molecules are essential for generating R in the Fe‐XO/HX system. It is expected that the toxicity of R would be greater than of hydrophilic O2−and OH because they are liposoluble and their lives are longer and the active sites of biomolecules are closely related with lipophilic phase, thus they can damage cells more seriously than O2−and OH. The R generated from the saccharide containing Fe‐XO/HX can be effectively scavenged by selenium containing abzyme (Se‐abzyme), indicating Se‐abzyme is a promising antioxidant.

The free radicals generated from the iron containing system of xanthine oxidase and hypoxanthine (Fe-XO/HX) were directly detected by using spin trapping. It was found that not only superoxide anion (O 2− ) and hydroxyl radical (OH ), but also alkyl or alkoxyl radicals (R ) were formed when saccharides such as glucose, fructose and sucrose were added into the Fe-XO/HX system. The generated amount of R was dependent on the kind and concentration of saccharides added into the Fe-XO/HX system and no R were detected in the absence of saccharides, indicating that there is an interaction between the saccharide molecules and the free radicals generated from the Fe-XO/HX system and saccharide molecules are essential for generating R in the Fe-XO/HX system. It is expected that the toxicity of R would be greater than of hydrophilic O 2− and OH because they are liposoluble and their lives are longer and the active sites of biomolecules are closely related with lipophilic phase, thus they can damage cells more seriously than O 2− and OH . The R generated from the saccharide containing Fe-XO/HX can be effectively scavenged by selenium containing abzyme (Se-abzyme), indicating Se-abzyme is a promising antioxidant.

Abstract: Selenium-containing abzyme (m4G3) was prepared and its protection of myocardial mitochondria against oxidative damage was studied using the swelling of mitochondria, quantity of lipid peroxidation products, and change in cytochrome-c oxidase activity as a measure of mitochondrial damage. The results showed that m4G3 could inhibit mitochondrial damage caused by the hypoxanthine-xanthine oxidase system in vitro. Electronic spin resonance (ESR) studies demonstrated that m4G3 could decrease the amount of free radicals generated in the damage system.

On the basis of cyclodextrin, 6-selenium bridged β-cyclodextrin (6-β-CD-Se-Se-β-CD, known as 6-SeCD) was synthesized by the selective tosylation of β-cyclodextrin and nucleophilic displacement by sodium hydroselenide to imitate glutathione peroxidase (GPX). The GPX activity of diselenide 6-SeCD is 4.3 times that of PZ51. The structure of the mimic 6-SeCD was characterized by means of laser mass spectroscopy, elemental analysis, IR and1H NMR. The selenium content and its valence in 6-SeCD were determined by means of X-ray photoelectron spectra. Kinetics of the mimic showed that its enzymatic behavior was similar to that of native GPX.

A chemical derivative of trypsin, selenotrypsin, was prepared to imitate glutathione peroxidase (GPX) by converting active serine residues in the active site of trypsin into selenocysteines. The strategy for preparation of selenotrypsin contained selective sulfonation by phenylmethanesulfonyl fluoride and nucleophilic substitution by NaHSe. Seleno-trypsin displayed enzyme activity of GPX, which is 150U/(mol. The kinetic properties of selenotrypsin was demonstrated to be similar to that of native GPX. © Rapid Science Ltd. 1998

The generation of 489 nm blue light by direct frequency doubling a CW 978 nm InGaAs diode laser radiation was demonstrated in optical superlattice LiNbO3 crystals at room temperature. When the incident power was 150 mW, 1.35 and 1.0 mW blue lights were achieved in the samples with and without an enhancement cavity, respectively.

The new lactam (I) and the three new terpenoids (II)—(IV) are isolated from the whole plant of Euphorbia helioscopia.