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The study investigated the effect of fibre laser processing (1060 nm, 240 ns pulse duration) on tungsten carbide (WC). Fluence, frequency, and the interaction effect of these were the most influential factors on the surface integrity and crack formation. In this paper, a crack classification system was developed, and a crack density variable was introduced to estimate the number of cracks and crack type within a 1 mm2 area size. ANOVA was used to analyse how fluence (0.05–0.20 J/cm2) and frequency (5–100 kHz) altered the crack density. The crack density increased between 0.050–0.099 J/cm2 across all frequency settings then decreased as the fluence increased to 0.20 J/cm2. Superficial cracks were present in all frequency settings but particularly with lower fluence settings. Micro-cracks were more likely to form between 0.050–0.135 J/cm2. Deep cracks did not present until 40 kHz or above 0.099 J/cm2 across the frequency settings and were situated around balling and splatter defects. The crack density was minimised at 0.149 J/cm2 fluence and 52.5 kHz. To the author’s knowledge for the first time a quantitative analysis of the crack formation mechanism for brittle materials is proposed (post laser processing). In addition, a linear model generated to predict surface roughness performed best at moderate to medium level of processing (fluences in the region of 0.050–0.099 J/cm2) with an error between 1 % to 10 %. The model failed to predict the material response as accurately at higher fluences with percentage errors between 15 % to 36 %.

The removal of alkali and alkaline-earth metallic (AAEM) species from biomass and/or its pyrolysis-derived char is often required to mitigate ash-related issues during their combustion. Leaching of biomass with an acidic aqueous phase (AP) produced from its pyrolysis is a promising strategy but encounters several issues, including high moisture content in wet biomass after dewatering and loss of organic carbon from biomass. Here, we propose a new process that leaches char with pyrolytic AP for the removal of AAEM species from and the uptakes of water-soluble organics by char. The char and pyrolytic AP produced from the pyrolysis of wheat straw at 450 °C in an auger reactor were subjected to time-dependent leaching at a liquid-to-solid mass ratio of 20. The results demonstrate that the majority of K, Mg, and Ca are leached within the first hour. Nonacidic compounds in the pyrolytic AP slightly hinder the leaching of K but have no impacts on that of Mg and Ca. Except for acetol, the uptakes of other organic compounds (e.g., furfural and phenolic compounds) by char are rapid in the first hour, become slower in 1–2 h, and then reach equilibrium. The results from density functional theory (DFT) calculations suggest the presence of chemisorption for the interactions between these organic compounds and char. Repeated leaching runs at the optimized leaching time (1 h) suggest that the pyrolytic AP is sufficient for leaching the char from the same run, achieving removal rates of ∼63.7 wt % for K, ∼43.7 wt % for Mg, and ∼60.7 wt % for Ca. After repeated leaching, there are only four organic compounds, including 2,3-butanedione, acetol, 2(5H)-furanone, and the remaining acetic acid, left in the leachate, simplifying the compositions of the pyrolytic AP. Leaching the char, instead of wheat straw, with the pyrolytic AP offers significant advantages, including the reduced moisture content in the wet solid after dewatering, negligible loss of organic carbon, and enhanced capture of phenolic compounds.

Introduction Citri Sarcodactylis Fructus (CSF) is widely used as a food ingredient and a traditional Chinese medicine. In China, CSF is cultivated in many places, including Sichuan, Guangdong, Zhejiang, and Fujian provinces. The types and chemical contents of CSF from different origins may vary greatly due to the difference in climate and environmental conditions. Therefore, comparing the chemical composition of CSF from various places is vital. Objective To rapidly select potential characteristic compounds for differentiating CSF from different origins. Material and methods Thirty-one batches of CSF samples from different regions were analysed using ultra-performance liquid chromatography with hybrid quadrupole-orbitrap high-resolution mass spectrometry. Thereafter, chemometric methods, including principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA), were employed to find differential metabolites among the CSF samples from various origins. Results PCA revealed 77.9% of the total variance and divided all CSF samples into three categories corresponding to their origins. OPLS-DA displayed better discrimination of CSF from different sources, with R2 X, R2 Y, and Q2 of 0.801, 0.985, and 0.849, respectively. Finally, 203 differential metabolites were obtained from CSF from different origins using the variable importance in projection of the OPLS-DA model, 30 of which were identified, and five coumarin compounds were selected as marker compounds discriminating CSF from different origins. Conclusion This work provides a practical strategy for classifying CSF from different origins and offers a research foundation for the quality control of CSF.

A couple of enantiomers of 2, 6-diaminotriptycene ( R, R - 1 and S, S - 1 ) are split by chiral HPLC and their absolute configurations are identified by single-crystal X-ray diffraction technology. Using the enantiomers as monomers, a couple of chiral porous polyimides ( R - FTPI and S - FTPI ) are prepared by polycondensation reactions and display good heat stability, high BET surface area and good solubility in organic solvents. Moreover, both of R - FTPI and S - FTPI can be cast into robust, free-standing films suitable for enantioselective separation with symmetrical chiral selectivity.

Surface friction plays a significant role in the machining performance and life of cutting tools. This investigation examines the influences of laser produced periodic textures on lubrication across the tool’s rake face and the influence on cutting forces when orthogonal turning steels exhibiting ductile chip behaviour. Laboratory tribology and orthogonal turning experiments on TiCN/Al2O3/TiN CVD coated tool inserts enhance understanding of the role of textures in the reduction of cutting forces and coolant film behavior in the sliding pairs by showingshifts in lubrication regimes from boundary to mixed and hydrodynamic, depending on operating parameters, texture design and coverage.

Selective hydrogenation of lignocellulosic biomass-derived chemicals is of great importance for future energy and chemical supply. So far formic acid is considered as one of the most promising materials for hydrogen storage. Herein, we report a novel pathway for the hydrogenation of Levogluosenone (LGO), a biorenewable platform chemical, to dihydrolevoglucosenone (Cyrene) and levoglucosanol (Lgol) using formic acid as a hydrogen source. Testing of typical hydrogenation catalysts indicated the crucial influence of the type on reaction selectivity and identified Pd/C as the most suitable catalyst. Among solvents screened, THF in combination with Pd/C showed the best performance for LGO hydrogenation, producing Cyrene in >99% yield at a low temperature (60 °C). Nevertheless, hydrogenation of Cyrene to Lgol required a harsher condition as a result of the difficult reduction property of its C=O bond. Elevating the reaction temperature to 180 °C and increasing double Pd dosage were capable to highly yield Lgol, attaining to 94.8%.

Two new phenolic glycosides 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-3'-O-(3''-α-L-arabinofuranosyl)-β-D-glucopyranoside. (1), 4-(4'-hydroxyphenyl)-2-butanone-4''-O-(6-β-D-xylosyl)-β-D-glucopyranoside (2), along with two known related analogues 7R,8R-threo-4,7,9,9'-tetrahydroxy-3-methoxy-8-O-4'-neolignan-3'-O-β-D-glucopyranoside (3), 4-(4'-hydroxyphenyl)-2-butanone-4'-O-β-D-glucopyranoside (4) were obtained from the roots of Sanguisorba officinalis. Combined with acid hydrolysis derivatization, the absolute configurations of these new compounds were elucidated by comprehensive analyses of spectroscopic data including nuclear magnetic resonance (NMR), electrospray ionization high resolution mass (HRESIMS) as well as circular dichroism (CD). Compounds 1-4 exhibited anti-inflammatory properties in vitro by attenuating the production of inflammatory mediators, such as nitric oxide (NO) as well as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

Ag2WO4 is a typically noble metal based photocatalyst with highly efficient photocatalytic activity. However, due to photocorrosion, the pristine Ag2WO4 is prone to inactivation during illumination. Constructing composite photocatalyst may be a useful method to promote the stability of Ag2WO4. In this work, Ag2WO4/graphitic carbon nitride nanotubes (g-C3N4 NTs) composite photocatalyst was prepared by adopting an in-situ composite strategy. The photocatalytic performance of the samples was discussed by the degradation of rhodamine B under visible light, and the catalytic mechanism was also analyzed. The characterization results show that the photocatalytic efficiency of the as-prepared Ag2WO4/g-C3N4 NTs composite increases firstly and then decreases along with the increase of the Ag2WO4 content. When the theoretical molar ratio of Ag2WO4:g-C3N4 NTs reaches 3:2, the photocatalytic degradation efficiency achieves the optimal value, that is 92.4% within 20 min, which obviously exceeds 2.8% of pure Ag2WO4 and 48.9% of pure g-C3N4 NTs. Moreover, the separation and migration efficiency of photoelectron–hole pairs of the composites can be accelerated in comparison with pure samples. In addition, superoxide radicals and hydroxyl radicals play major roles in the photocatalytic degradation process.

The SnO2 quantum dots (SnO2QDs)/ZnS nanosheets (ZnSNs) heterojunction was fabricated via an in-situ synthetic method at room temperature. Rhodamine B, potassium dichromate, and tetracycline were used to discuss the photocatalytic activities of the as-prepared samples under the visible light illumination. The photocatalytic mechanism of the as-prepared samples was also proposed. The experimental results indicate that the degradation efficiency of the as-prepared SnO2QDs/ZnSNs heterojunction first increases and then decreases with increasing the usage of ZnSNs. When the mass ratio of SnO2QDs to ZnSNs is 1: 2 in 180 min, the asprepared samples have the highest degradation efficiency of 89.1% for rhodamine B, 97.7% for potassium dichromate, and 83.8% for tetracycline, which are much higher than 51.7%, 26.8%, and 0.9% of pure SnO2QDs as well as 37.9%, 87.1%, and 19.1% of pure ZnSNs, respectively. After it is repeatedly degraded for 3 times, it possesses the degradation efficiency of 62.5% for rhodamine B, which increases by 200.5% in comparison with 20.8% of the pure SnO2QDs. Moreover, the enhanced photocatalytic performances of the as-prepared hybrids are attributed to the formation of heterojunction between the SnO2QDs and ZnSNs. In addition, hydroxyl radicals and superoxide anion radicals play major roles during the photocatalytic degradation process, while holes play a minor role.

Pyrolysis is the simplest way to convert lignin into phenolic compounds as monomers but inevitably producing oligomers as heavy oil (HO). We propose a particular type of pyrolysis, which recycles s...

Objectives Metabolic reprogramming is well accepted as a hallmark of cancer. This study aimed to explore the role of Kruppel-like factor 2 (KLF2) in aerobic glycolysis and glutamine consumption of energy metabolism in non-small cell lung cancer (NSCLC) cells. Methods Two different NSCLC cells, A549 and NCI-H1299, were used to investigate the role of KLF2 in glycolysis and glutamine consumption by tracer technique and KLF2 transfection. Key findings The results showed that overexpression KLF could inhibit the energy metabolism and proliferation of NSCLC cells, but had no significant effect on glycolysis reaction and only affected the glutamine consumption of NSCLC cells. In NSCLC cells exposed to glutamine deprivation, the effect of overexpression of KLF2 on cell proliferation and energy metabolism disappeared. It was found that KLF2 could inhibit the expression of glutaminase (GLS) by metabolite tracing technique and so on. However, when GLS inhibitors were given to overexpressing KLF2 NSCLC cells, the intervention effect of KLF2 disappeared. Conclusions Kruppel-like factor 2 could decrease the level of glutamine, participate in the consumption of glutamine by cancer cells, and then inhibit the energy metabolism of cancer cells.

Catalytic fast pyrolysis of sawdust was investigated over HZSM-5 zeolites (SiO2/Al2O3 = 25, 50 and 80) in a drop tube quartz reactor for production of green aromatics and olefins. The effects of temperature, weight hourly space velocity (WHSV), SiO2/Al2O3 ratio and atmosphere on yield and selectivity of aromatics were investigated. The results show that almost all small organic oxygen species in initial volatiles were converted into gaseous hydrocarbons and aromatics after in situ catalysis of HZSM-5. HZSM-5 whose SiO2/Al2O3 is 25 exhibited the best performance with the aromatics yield of 21.8% on carbon basis at 500 °C. However, HZSM-5 can act as cracking and aromatization catalyst, but not as an agent to promote hydrogenation. The ESI-MS revealed the most abundant macromolecular compounds in initial volatiles were O1 O27 species with 0–20 double bond equivalent (DBE) values and 5–40 carbon numbers, while the macromolecules were O1 O9 species with 2–12 DBE and 10–25 carbon numbers after upgrading. Furthermore, the formation of coke on catalysts was influenced by the properties of HZSM-5 and experimental conditions.

As part of our search for compounds with cytotoxicity from endophytes of traditional Chinese medicines, two novel nor-sesquiterpenoids (1–2) with a new skeleton containing a tetrahydrofuran moiety were isolated form a rice medium of Fusarium tricinctum, an endophytic fungus isolated from the root of Ligusticum chuanxiong. The structures of these two previously undescribed compounds were elucidated by interpretation of the spectroscopic evidences including NMR correlations as well as MS data. The absolute configurations of these two compounds were confirmed by TD-DFT-ECD calculations. An MTT assay indicated that compound 1 exhibited moderate cytotoxic activity against MV4-11 with an IC50 value of 22.29 μM.

The synergistic anti-tumor effect of a typical chemotherapy drug, 5-fluorouracil, and a natural flavonoid compound, kaempferol, has been reported recently. However, the oral absorption of 5-fluorouracil is incomplete and nonuniform for different individuals due to fast metabolism and an obvious peak-valley phenomenon, while kaempferol has very poor solubility and this consequently leads to low oral bioavailability. The weakness of each drug greatly restricts the potential of anti-tumor drug combination in the clinical application. In this work, a new 1 : 1 drug–drug cocrystal of 5-fluorouracil and kaempferol was successfully prepared by liquid assisted grinding, slurry conversion crystallization and evaporation crystallization. A ternary phase diagram was constructed to gain some insights into the thermodynamics of the cocrystal system. The obtained cocrystal was comprehensively characterized by single crystal and powder X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis, as well as Fourier transform infrared and nuclear magnetic resonance spectroscopy. The drug–drug cocrystal enhances the stability of kaempferol and optimizes the dissolution behavior of each single component as compared to pristine drugs. Therefore, the 5-fluorouracil–kaempferol cocrystal has the potential to be developed as efficient oral formulations for drug combination which will overcome the weaknesses of each parent drug.

It is a great challenge to tune the porosity of porous materials. As most porous organic cages are soluble, solution processability can be a possible way to regulate the porosity of such materials. Herein, a triptycene-based cage (TC) is demonstrated to be stable in acid, base or boiling water. Meanwhile, its porosity can be tuned by adjusting the solution-state assembly processes. TC molecules crystallized slowly from solution exhibit nearly no porosity to nitrogen (off-state). While, after rapid precipitating from methanol/dichloromethane solution, the obtained TC (TC-rp) is in a porous state and exhibit a high BET surface area of 653 m2 g−1 (on-state).

Background Hypothermia is a powerful neuroprotectant. However, clinical translation has been difficult partly because the underlying mechanisms remain to be fully elucidated. Recently, it has been suggested that hypothermic neuroprotection may be linked with specific microRNA signatures, specifically the downregulation of miR-194-5p. Here, we attempt a reverse translation study to define the novel neuroprotective mechanism of miR-194-5p downregulation. Methods Our research designed experiments to determine the expression of miR-194-5p in hypothermic neuroprotection. After transfected with miRNA-194-5p inhibitor or control miRNA, neuron cells were performed Oxygen-glucose deprivation (OGD) and reoxygenation. Cell viability was determined by staining with propidium iodide (PI) and expression of SUMO-2 were quantified using Western blot. Luciferase reporter assays were performed to verify the direct binding of miR-194-5p to SUMO2 transcripts. Puromycin and recombinant lentivirus (pLKD-CMV-eGFP-sumo2-shRNA) were used to suppressed SUMOylation non-specifically and specifically. Results First, we documented that miR-194-5p was highly expressed in rat primary cortical neurons and astrocytes, compared with other glial and vascular cell types. Blockade with anti-miR-194-5p did not affect astrocytes, but significantly protected neurons against oxy-glucose deprivation. Using a miRNA target prediction algorithm, we found that SUMO-2, a known endogenous neuroprotective regulator, possessed the binding site for miR-194-5p. When miR-194-5p was inhibited, SUMO-2 mRNA was increased in neurons along with the enhancement of SUMO-2 conjugation. Finally, downregulation of SUMO-2 with none-special puromycin and special lentiviral shRNA-mediated knockdown of SUMO2 both canceled the neuroprotection mediated by miR194-5p inhibition. Conclusion Taken together, this study provides the first proof-of-concept that miR194-5p may be a negative controller of endogenous SUMO-2 protective mechanisms, and therefore miR194-5p inhibition may provide a novel approach for leveraging hypothermic neuroprotection against ischemic stress.

Here, we report a new application using liquid chromatography-electrospray mass spectrometry (UHPLC-ESI-MS) using aldononitrile acetate derivatives for simultaneous baseline separation and detection of eight neutral saccharides, two uronic acids, one ketose, and eight alditols within 14 min. The separation was performed on a Cortecs C₁₈ column using acetonitrile (A) and water (B) as the mobile phase with gradient elution. The target components were detected in selected ion monitoring (SIM) mode by mass spectrometry with an electrospray ionization (ESI) source operating in positive ionization mode. A comparison with traditional methods was used to determine the validity of the results. The UHPLC-ESI-MS method was used for quantitative analysis of free carbohydrates in water extracts of Crataegus pinnatifida as well as determination of Polygonatum cyrtonema and Glossy ganoderma monosaccharides in polysaccharides. The results demonstrate that this protocol is a comprehensive and effective technique for qualitative and quantitative analysis of plant polysaccharides from TCMs.

Polycrystalline diamonds, polycrystalline cubic boron nitrides and tungsten carbides are considered difficult to process due to their superior mechanical (hardness, toughness) and wear properties. This paper aims to review the recent progress in the use of lasers to texture hard and ultra-hard materials to a high and reproducible quality. The effect of wavelength, beam type, pulse duration, fluence, and scanning speed is extensively reviewed, and the resulting laser mechanisms, induced damage, surface integrity, and existing challenges discussed. The cutting performance of different textures in real applications is examined, and the key influence of texture size, texture geometry, area ratio, area density, orientation, and solid lubricants is highlighted. Pulsed laser ablation (PLA) is an established method for surface texturing. Defects include melt debris, unwanted allotropic phase transitions, recast layer, porosity, and cracking, leading to non-uniform mechanical properties and surface roughness in fabricated textures. An evaluation of the main laser parameters indicates that shorter pulse durations (ns—fs), fluences greater than the ablation threshold, and optimised multi-pass scanning speeds can deliver sufficient energy to create textures to the required depth and profile with minimal defects. Surface texturing improves the tribological performance of cutting tools in dry conditions, reducing coefficient of friction (COF), cutting forces, wear, machining temperature, and adhesion. It is evident that cutting conditions (feed speed, workpiece material) have a primary role in the performance of textured tools. The identified gaps in laser surface texturing and texture performance are detailed to provide future trends and research directions in the field.

Background Skin injury and the resultant defects are common clinical problems, and usually lead to chronic skin ulcers and even life-threatening diseases. Copper, an essential trace element of human body, has been reported to promote the regeneration of skin by stimulating proliferation of endothelial cell and enhance angiogenesis. Results Herein, we have prepared a new donut-like metal–organic frameworks (MOF) of copper-nicotinic acid (CuNA) by a simple solvothermal reaction. The rough surface of CuNA is beneficial for loading/release basic fibroblast growth factor (bFGF). The CuNAs with/without bFGF are easily processed into a light-responsive composite hydrogel with GelMA, which not only show excellent mechanical properties, but also display superior biocompatibility, antibacterial ability and bioactivity. Moreover, in the in vivo full-thickness defect model of skin wound, the resultant CuNA-bFGF@GelMA hydrogels significantly accelerate the wound healing, by simultaneously inhibiting the inflammatory response, promoting the new blood vessels formation and the deposition of collagen and elastic fibers. Conclusions Considering the superior biocompatibility, antibacterial ability and bioactivity, the CuNA and its composite light-responsive hydrogel system will be promising in the applications of skin and even other tissue regeneration. Graphic abstract

The structural characteristics of the polysaccharides from Aralia elata root barks (AERP) were systematically investigated by FT-IR, HPSEC-ELSD and colorimetric methods as well as by GC MS based monosaccharide compositions, Smith degradations, and methylation analysis. The result showed average molecular weights of AERP were between 42.7 kDa and 93.9 kDa. AERP was composed of Ara, Rha, GlcA, Man, Glc, and Gal in a molar ratio of 22.2: 10.3: 8.1: 32.7: 5.7: 21.2 along with a small number of sulfate (3.38%) and acetyl (4.87%) groups. The abundant glycosidic linkages of Man, Ara, Gal, and Rha were observed as more than 90% of all the monosaccharides detected. Studies to evaluate hepatoprotective potentials of AERP showed that they had potent hepatoprotective effects in vivo in carbon tetrachloride-induced acute liver injury (CIALI) in mice by histopathological evaluation, biochemical examinations and ELISA assays. GC MS was further used to determine the effects of AERP on the chemical profiles of nine common short-chain fatty acids (SCFAs) produced by intestinal flora metabolism in CIALI mice. These findings not only provide novel insights into the pharmacological actions of AERP on the protection from CIALI in mice, but they also demonstrate that determining SCFA profiles by targeted GC–MS metabolomics is an effective technique to investigate the molecular mechanisms of the effects of plant polysaccharides on intestinal flora metabolism.

Oral squamous cell carcinoma (OSCC) is the most common cancer of the oral cavity. Curcumin (Cur), a naturally derived compound, is reported to have broad-spectrum anticancer activity and is considered as an effective nuclear factor-κB (NF-κB) inhibitor. The present study aimed to clarify the detailed molecular mechanism though which Cur regulates NF-κB pathway activity in OSCC. The viability of HSC3 and CAL33 cells following treatment with Cur was determined using a Cell Counting Kit-8 assay. The protein and mRNA expression of specificity protein 1 (Sp1), p65 and heat shock factor 1 (HSF1) was determined by western blotting and reverse transcription-quantitative PCR analysis, respectively. The NF-κB activity was measured by Dual-Luciferase reporter assay. Short hairpin RNA targeting Sp1 or control RNA was transfected into HSC3 cells using X-treme GENE HP DNA Transfection System. Colony formation assays were performed using crystal violet staining. The results demonstrated that Cur significantly inhibited the viability and colony formation ability of HSC3 and CAL33 cells. In addition, Cur decreased the expression of Sp1, p65 and HSF1 by suppressing their transcription levels. Cur decreased NF-κB activity in OSCC cells, and Sp1 downregulation enhanced the effect of Cur. The findings from the present study suggested that Cur may inhibit the proliferation of OSCC cells via a Sp1/NF-κB-dependent mechanism.

A series of Zn-containing HZSM-5 (HZ5) with hierarchical pores (xZn(DS)) were obtained by adding different amounts of Zn(NO3)2 solution in a hydrothermal synthesis process. The performances of xZn(DS) in catalytic reforming of cellulose pyrolysis volatiles were investigated at 500 °C. The results showed that the addition of Zn during synthesis increased in the total pore volume of xZn(DS) and reduced the content of strong acid sites, and introduced new weak acid sites. The Zn species were highly dispersed inside the zeolite, and enhanced the accessibility of acid sites, so that the yields of light aromatic hydrocarbons and monocyclic aromatic hydrocarbons (MAHs) over 0.7Zn(DS) (The molar ratio of ZnO/Al2O3 in the synthesis process of xZn(DS) was 0.7) were higher than those over S-HZ5 (Zn was not added in the synthesis process) and commercial HZ5. Compared with S-HZ5, the yield of MAHs over 0.7Zn(DS) increased from 92.8 to 114.1 mg/g and the coke yield decreased by 2.9%. The selectivity of MAHs over 0.7Zn(DS) was 87.7%, which was 5.3% higher than that over S-HZ5. Simultaneously, the increase in mesopores of xZn(DS) accelerated the mass transfer process, shortened the diffusion path and improved the anti-coking performance of the catalysts. In addition, this study also proposed a possible mechanism for the catalyst to adjust the distribution of aromatic products and provided a new idea for promoting the selective production of MAHs for the pyrolysis of cellulose.

HZSM-5 was hydrothermally synthesized by Ga substitution to regulate the texture properties for light aromatics such as benzene, toluene, ethylbenzene, xylenes and naphthalene (BTEXN) during the lignite volatiles catalytic upgrading process. High BTEXN yield was obtained over xGa/H5(A) (added NaOH in crystallization) and the value increased with raising the amount of Ga incorporation when the Ga content was

Tribological performance of systems in boundary lubrication is dependent on contact and lubricant conditions such as temperature, lubricant additive concentration, surface characteristics, contact pressure and additive-additive interactions. Although past parametric studies have investigated these various factors, there are limited studies on the effect of surface topography on the performance of boundary lubrication additives. This is pertinent because of the increased use of surface texturing in lubricated contacts. This study has employed laser surface texturing to achieve surfaces with different topographies. The influence of the different surface topographies on the tribological performance of a friction modifier additive, molybdenum dialkyldithiocarbamate (MoDTC), was investigated. Results show that laser-textured surfaces in some instances can offer improved friction performance compared to non-textured (polished) surfaces when working positively with a friction modifier additive. Anisotropic surfaces resulted in improved friction. The mechanism for the improved performance of the laser-textured surfaces is believed to be through the augmented local contact pressures at the asperities that accelerate additive decomposition to form protective low-friction tribofilms. This study demonstrates the feasibility of surface texturing in improving the performance of boundary additives.

Sandblasting is an established technique in generating surface textures on titanium and other metal alloys; these surfaces are desirable in the field of biomedical engineering as they promote osseointegration of medical implants. However, this process has significant limitations including, the embedment of abrasive particles causing changes to surface composition, lack of automation, and health hazards. Laser processing is becoming more common in the medical industry as a method to generate surface textures. Nanosecond laser systems are generally used in surface processing for their benefits of productivity and cost; however, the ultra-short pulsed lasers induce less thermal damage. This study probes the use of stochastic laser processing (laser-blasting) as an alternative to sandblasting to modify surfaces of Ti6Al4V. Laser processing parameters such as power and pulse durations were investigated in both nanosecond and femtosecond laser systems operating in the IR region. Surface morphology and microstructural changes of laser blasted samples were inspected using a variety of techniques (confocal microscopy, SEM and EDX) and then compared with those that had been sandblasted. The results obtained show that through careful selection of parameters, laser-blasting is capable of generating similar surfaces produced by sandblasting with limiting thermal damage.

To investigate the relationship between acetyl cholinesterase associated collagen gene (COLQ) mutation in patients with acetyl cholinesterase deficiency and its clinical characteristics. Serum and red blood cell acetyl cholinesterase from patients with acetyl cholinesterase deficiency (n=6) and normal controls (n=20) were measured by butyryl thiocholine substrate. COLQ gene variations were detected by sequencing. And the cholinesterase (ChE) genotypes were measured by dibucaine inhibition in vitro. The distributions of ChE surrounded the blood vessels and nerve fibers in lung or pancreas tissues were detected by immunohistochemical staining and indirect immunofluorescence. Serum lactic acid, ammonia and other clinical data were analyzed. Serum ChE in patients with acetyl cholinesterase deficiency were only 1/50 to 1/1000 fold of normal controls. Comparing to controls, dibucaine inhibition values of patients were significantly lower, while there were no differences in red blood cells acetyl cholinesterase. Serum lactic acid and ammonia in patients were significantly higher than controls. Inser 1281-1282 GC of COLQ gene was found in 2 patients, while IVS 6 + 21 T > A, IVS 6 + 30 G > T, IVS 6 + 34 T > C and IVS66 + 12 inser T mutations were found in the other 4 patients, respectively. In addition, the patients with COLQ gene mutation were resistant to regular doses of anesthetics. COLQ gene mutation may be an important reason for the lack of serum ChE in patients with acetyl cholinesterase deficiency.

Highly porous carbonaceous nonprecious metal catalysts for the oxygen reduction reaction are prepared by carbonization of low-cost metalloporphyrin-based hyper-crosslinked polymers (MPH-X). With high surface area (2768 m2 g-1 ), hierarchical porous structure, and high metal loading (9.97 wt %), the obtained hyperporous carbon MPH-Fe/C catalyst exhibits high oxygen reduction reaction (ORR) activity with a half-wave potential (0.816 V) that is comparable to the 0.819 V of commercial Pt/C. Stability tests reveal that MPH-Fe/C also exhibits outstanding long-term durability and methanol tolerance. Our findings may offer an alternative approach to produce nonprecious metal ORR catalysts on a large scale owing to the low-cost MPH-X precursors with diverse metal types.

HZSM-5 was modified via alkaline treatment and wet impregnation method which loading transition metals (Co, Mo–Co and Ni–Co). The performance of catalysts for the catalytic fast pyrolysis of lignite was tested in a drop tube reactor at 600 °C. In comparison to non-catalytic experiment, the chemical composition of upgrading tar was obviously simplified, which mainly contains light aromatics such as benzene, toluene, ethylbenzene, xylene and naphthalene (BTEXN). The yield of BTEXN was significantly increased from 12.9 to 26.4 mg/g when Ni/Co-H-5 was used. Meanwhile, the Ni/Co-H-5 treated by NaOH solution achieved considerable deoxygenation performance (86.6%) than other ones. The addition of bimetallic Mo–Co or Ni–Co significantly enhanced the BTEXN selectivity of HZSM-5. Ni promoted H2 formation in gaseous product and caused the decrease of naphthalenes yield. Whereas the yields of toluene and o-xylene increased after the pyrolysis vapors pass through Mo/Co-H-5. The zeolite treated by NaOH solution (AT-HZSM-5) favors the generation of aromatics and phenolics, conversely naphthalene derivatives. Moreover, AT-Mo/Co-H-5 and AT-Ni/Co-H-5 inhibited the coke formation. A catalytic pathway was also proposed to describe the diffusion process of pyrolysis vapors on the active site of catalyst.

TiO2/reduced graphene oxide (rGO) nanocomposites were prepared via a facile one-step hydrothermal method using TiCl3 as the TiO2 precursor. Cetyltrimethyl ammonium bromide (CTAB) was introduced as a stabilizer for GO in solution. The effects of GO content, Ti3+ concentration and urea additive on phase constituent and morphology of the TiO2 crystallites in the nanocomposites were systematically investigated. UV–vis absorption ability of the as-made composites was further tested and discussed. Ag nanocrystals (NCs) were photocatalytically grown on the surfaces of biphasic (anatase + brookite) and triphasic (anatase + brookite + rutile) TiO2/rGO nanocomposites to evaluate their surface-enhanced Raman scattering (SERS) performances. Morphology evolution of the Ag NCs in response to different photocatalytic ability of the TiO2/rGO nanocomposite was also investigated in detail. The nanocomposite with triphasic TiO2 of proper phase constituents was confirmed to favor the growth of Ag particles of two distinctly different sizes and to produce SERS substrates of substantially better performance.

The development of cheap and highly dispersed nano-catalyst is one of the key technologies for low temperature steam reforming (SR) of biomass tar. This work used acid-washed and oxidized Shengli lignite char (OXAWSL) as carbon precursor to load Co (Co/OXAWSL) and Ni (Ni/OXAWSL) via ion exchange method to SR of toluene and biomass tar. The Co/OXAWSL was more active and stable than Ni/OXAWSL during the 30 h test with a final toluene conversion of 85% at a relatively low temperature of 450 °C and steam to carbon ratio (S/C) of 3.4, which resulted from its small particle size (5.6 nm) and high dispersion (12.3%) of Co. The relatively high H2 production (42.59 mmol/g-biomass) over Co0.1/OXAWSL (450 °C, S/C = 3.4) in SR of tar was also obtained. A low Ea (22.0 kJ/mol) value of Co/OXAWSL and good affinity to oxygen for Co explained its excellent performance. The low-temperature tar cracking process can provide theoretical and technical support for the large-scale industrial utilization of biomass pyrolysis and gasification.

Ni-encapsulated (Ni@HZ5) and Ni-incorporated (xNi/HZ5) zeolites were prepared via one-pot hydrothermal synthesis and impregnation method, respectively, and further employed for hydroconversion of pyrolytic volatiles of spent coffee grounds into benzene, toluene, ethylbenzene, xylene, naphthalene (BTEXN) in a drop tube reactor under H2 atmosphere. The properties of metallic Ni species on Ni@HZ5, xNi/HZ5 and Ni/Al2O3 were comparably characterized. Ni@HZ5 displayed superior selectivity for BTEXN production among those catalysts, especially for B and T. Metallic Ni species encapsulated MFI-type framework plays crucial roles in enhancing aromatics selectivity, promoting oligomerization, cyclization and aromatization of small molecular hydrocarbons in channels. On the contrary, Ni species presented on the external zeolite surface is in favor of hydrocracking and hydrogenolysis of macromolecular pyrolytic fragments. It also exhibited high coke content containing “soft” and “hard” coke, which was mainly caused by metallic particles sintering. An important difference was proposed in the effect of Ni species on reaction pathway for catalytic upgrading of volatiles to BTEXN. The configured Ni@HZ5 inhibits sintering and has potential of enhancing BTEXN by catalytic hydropyrolysis of biomass.

Visible-light-driven WO3and#183;0.33H2O/Ag2MoO4 composites have been prepared by using an in-situ growth of Ag2MoO4 nanoparticles on the surfaces of WO3and#183;0.33H2O. The photocatalytic activities of the samples were studied by degradation of rhodamine B and levofloxacin dilute solution. The synergistic photocatalytic mechanism was also analyzed. Experimental results reveal that the as-developed hybrids have higher photocatalytic activity than pure samples. When the theoretical molar ratio of WO3and#183;0.33H2O to Na2MoO4and#183;2H2O is 1:0.15, the as-developed hybrids have the highest photocatalytic degradation efficiency of 99.0% for rhodamine B in 45 min and 40.9% for levofloxacin in 120 min. Furthermore, there are chemical bonds between WO3and#183;0.33H2O and Ag2MoO4. In addition, the super oxide radicals play the leading role during the photocatalytic degradation process of the samples. This work will provide reference for treatment of organic dyes and antibiotics pollution in water with using solar energy.

A novel porous carbon catalyst was prepared by carbonization of D151 resin exchanged with nickel ion (Ni/RC). TEM images and XRD patterns manifest that nickel crystallite size (NCS) relies greatly on solution pH value and carbonization temperature. The as-prepared Ni/RC in pH 11 at 650 °C achieved the maximal specific surface area of 213 m 2 /g and metallic nickel particles are highly dispersed with a NCS of 5.7 nm. Ni/RC exhibited higher activity for corncob tar reforming than commercial Ni/Al 2 O 3 and produced a gas yield of 46.8 mmol/g at 650 °C. The nickel particles growth above 650 °C causes the decline in catalytic activity of Ni/RC. In the presence of steam, a high tar-free gas of 84.5 mmol/g was obtained at 650 °C. This study sheds light on the possibility of Ni/RC as a promising candidate for H 2 -rich gas production from biomass under mild conditions.

Hierarchical β -NaGdF 4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF 4 -GdF 3 -NaGdF 4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of β -NaGdF 4 at a low NaF/Gd 3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like β -NaGdF 4 nanobundles are obtained. The photoluminescent properties of β -NaGdF 4 : 2%Eu 3+ are also measured.

Lignite is rich in oxygen-containing species (OCSs) and able to load Ni via ion exchange to prepare Ni/C catalyst. However, the OCSs usually exists in the form of organic salts, which can reduce the capacity of Ni ion exchange. In this paper, Shengli lignite (SL) was treated with HCl and HCl/HF to selectively remove the organic salts and insoluble minerals, respectively, and the modified lignite was oxidized by H 2 O 2 to further increase the carboxyl content. The treated lignite was used to prepare Ni/C catalyst and the activity for biomass volatile reforming was evaluated. The results show that demineralization (DM) caused the corrosion of pore structure of SL and gave a Ni/C catalyst with a low specific surface area (SSA) of 222.1 m 2 /g. Oxidation with H 2 O 2 further destroyed the structure of DMSL and provided a Ni/C with the lowest SSA of 141.1 m 2 /g. Acid wash (AW) with HCl resulted in the increase of ion exchange capacity of SL and gave a Ni/C catalyst with larger SSA, higher loading, lower particle size and well dispersion of Ni particle in comparison with SL and DMSL. H 2 O 2 treatment of AWSL significantly increased the amount of carboxyl group to 3.8 mmol/g and gave a Ni/C with the largest SSA of 291.1 m 2 /g, highest Ni loading of 17.3% and smallest Ni crystallite size of 3.4 nm, as well as most active for corncob volatile reforming.

This paper presents an investigation on the titanium aluminium nitride (TiAlN) coating removal from tungsten carbide (WC-Co) substrate using a diode pump solid state (DPSS) ultraviolet (UV) laser with maximum average power of 90 W, wavelength of 355 nm and pulse width of 50 ns. The TiAlN coating of 1.5 μm thickness is removed from the WC-Co substrate with laser fluence of 2.71 J/cm2 at 285.6 number of pulses (NOP) and with NOP of 117.6 at 3.38 J/cm2 fluence. Titanium oxide formation was observed on the ablated surface due to the re-deposition of ablated titanium residue and also attributed to the high temperature observed during the laser ablation process. Crack width of around 0.2 μm was observed over both TiAlN coating and WC-Co substrate. The crack depth ranging from 1 to 10 μm was observed and is related to the thickness of the melted carbide. The crack formation is a result of the thermal induced stresses caused by the laser beam interaction with the material as well as the higher thermal conductivity of cobalt compared to WC. Two cleaning regions are observed and is a consequence of the Gaussian distribution of the laser beam energy. The surface roughness of the ablated WC-Co increased with increasing laser fluence and NOP.

An investigation on ablation characteristics of 1024 and H10F cobalt cemented tungsten carbide (WC-Co) with a DPSS nanosecond UV laser (50 ns pulse width, 355 nm wavelength, 90 W average power and 10 kHz repetition rate) is presented. The ablation characteristic parameters such as ablation threshold, incubation effect and optical penetration depth were evaluated based on the spot ablation diameter and depth. It was observed that the ablation threshold is significantly influenced by the number of pulses (NOP) and it decreases with increase NOP which is attributed to the incubation effect. Only one ablation region is observed at low laser fluence and an additional molten ablation region is observed at high laser fluence accompanied with cracks. The cracks formation is due to the thermal induced stress and changes in WC microstructure during laser beam irradiation. The crack depth is proportional to the thickness of the molten WC region. The ablation threshold of 1024 WC-Co and H10F WC-Co were found to be Fth1 =4.32 J/cm2 and Fth1 =4.26 J/cm2 respectively. The difference in chemical composition has insignificant effect on the ablation threshold value of the material. The incubation factor and optical penetration depth values of 1024 WC-Co and H10F WC-Co were found to be ξ=0.73, α−1 =411 nm and ξ=0.75, α−1 =397 nm respectively.

This work is aimed to study in situ upgrading of Shengli lignite pyrolysis vapors over different metal-loaded HZSM-5 in a drop tube reactor. Co/HZSM-5, Mo/HZSM-5 and Ni/HZSM-5 (5.0 wt%) were prepared by wet impregnation and characterized by N 2 adsorption-desorption analyzer, X-ray diffraction, transmission electron microscope, Fourier transform infrared spectrometer and temperature programmed desorption of ammonia. The effects of temperature and catalyst on product yields and tar properties were investigated. The results show that the optimal temperature for liquid product was 600 °C and aromatics can be directly produced from solid lignite by catalytic fast pyrolysis over metal-loaded HZSM-5 under such mild condition. Due to the participation of metal and acid sites, the bifunctional metal-loaded HZSM-5 showed comparable catalytic activity for deoxygenation reaction in the valorization of oxygen content below 7.1%. The introduction of metal causes the increase of aromatics and the decrease of organic oxygen species in upgraded tar remarkably. Among the catalysts, Ni/HZSM-5 exhibited the best performance for production of high quality tars with highest aromatics content of 94.2% (area%), which can be used as a potential candidate for catalytic upgrading of pyrolysis oil.

Fast pyrolysis of pine sawdust (PS) was investigated in a drop tube quartz reactor to understand the effects of temperature and atmosphere (Ar and H2) on the product yields, gas composition, bio-oil characteristics (organic composition and molecular mass distributions (MMDs)), and the carbon and oxygen conversion. The pyrolysis behavior and typical products from PS pyrolysis were also conducted using a thermogravimetry-mass spectroscopy (TG-MS) and pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS). The results show that the highest oil yields can be obtained at 500 °C of 55.09 and 54.41 wt.% under Ar and H2 atmosphere, respectively. In comparison to an inert atmosphere, H2 created lower oil yields but higher gas yields, especially for CO and CH4 yields, and narrower MMDs, smaller Mn and Mw, and fewer char especially at high temperatures. The high temperatures and H2 atmosphere contribute to the oxygen and carbon transferring from material to volatile, especially to the gaseous products. H2 can promote the secondary cracking of macromolecules and weaken the re-polymerization of anhydrosugar and lignin oligomers.

Different sizes of hexagonal spherical NaGdF4:Eu3+ particles are synthesized via a facile hydrothermal method with the use of ethylene glycol (EG), propylene glycol (PG) or butylene glycol (BG) as another solvent. The particle size decreases with the addition of EG, PG or BG and the decreasing trend in BG/H2O system is significantly more than that in the other two systems. Meanwhile, results show that luminescent properties of NaGdF4:Eu3+ are enhanced along with the decrease of particle size. Besides, the energy transfer from Dy3+ to Eu3+ is directly observed in the PL spectra of NaGdF4:Eu3+/Dy3+.

pH responsive polymeric nanoparticles have emerged as a promising technology platform for targeted and controlled drug delivery in recent years. In this paper, endosomal pH-activatable doxorubicin (DOX) and core-crosslinked polymeric nanoparticles (DCNPs) were prepared and investigated for potent growth inhibition of human cancer cells in vitro. In vitro drug release studies, DOX conjugated nanoparticles with hydrazone bond showed a pH sensitive release phenomenon, that is, the releasing is significantly faster at mildly acidic condition with pH of 5.5 than that at physiological condition. Confocal laser scanning microscope (CLSM) observations revealed that DOX conjugated nanoparticles delivered and released DOX into the cytosols as well as cell nuclei of Hela cells following 6 h incubation. MTT assays demonstrated that these pH-sensitive DOX nanoparticles exhibited high antitumor effect to HeLa cells. The conjugated DOX polymeric nanoparticles may be a promising candidate as a nanoscale and pH-sensitive drug delivery vehicle for cancer therapy.

The greater structural versatility of two-dimensional polymeric nanosheets could be available through the development of a bottom-up polymerization strategy compared with top-down nanosheets (such as graphene and metal chalcogenides). However, rational synthesis by solution polymerization has been a long-standing challenge. Considering that Glaser coupling is catalyzed by cuprous (I) salts with the participation of oxygen, an air/liquid interfacial coupling reaction has been designed and used to prepare a two-dimensional porous triptycene-based polymeric nanosheet (2D-PTNS). This 2D-PTNS shows a high BET surface area, good gas adsorption ability and excellent selective adsorption of C2H6/CH4 at ambient temperature and pressure.

Magnetic nanoparticle clusters with magnetization of about 80 emu/g and tunable size between 55 and 500 nm were synthesized through a bisolvent solvothermal process in the presence of ethylene glycol (EG) and diethylene glycol (DEG), triethylene glycol (TEG) or 1,2-propanediol (PG) with polyethylene glycol (PEG) or hexadecyltrimethyl ammonium bromide (CTAB) as surfactant. It was found that the volume ratio of EG to the other polyol played an important role in controlling the size and morphology of Fe 3 O 4 . Effect of the concentration of Ferric chloride hexahydrate (FeCl 3 ·6H 2 O) and original reactants on controlling the size of Fe 3 O 4 particles was also discussed.

AlGaN/GaN HEMT epistructures were grown on SI-SiC using different doping concentrations of carbon in GaN buffer layer to study the effects of carbon on various device parameters. The carbon doping was tuned by adjusting different growth parameters, and SIMS analysis was performed to determine the carbon doping density. HEMTs with $0.25 \mu \mathrm {m}$ gate length were fabricated and characterized. Some of the parameters studied include buffer leakage current, drain current density, OFF-state breakdown voltage and drain current collapse.

Low molecular weight seleno-aminopolysaccharide (LSA) is an organic selenium compound comprising selenium and low molecular weight aminopolysaccharide (LA), a low molecular weight natural linear polysaccharide derived from chitosan. LSA has been found to exert strong pharmacological activity. In this study, we aimed to investigate the protective effect of LSA on intestinal mucosal oxidative stress in a weaning piglet model by detecting the growth performance, intestinal mucosal structure, antioxidant indices, and expression level of intracellular transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and its related factors. Our results indicated that LSA significantly increased the average daily gain and feed/gain (p &lt, 0.05), suggesting that LSA can effectively promote the growth of weaning piglets. The results of scanning electron microscope (SEM) microscopy showed that LSA effectively reduced intestinal damage, indicating that LSA improved the intestinal stress response and protected the intestinal structure integrity. In addition, diamine oxidase (DAO) and d-lactic acid (d-LA) levels remarkably decreased in LSA group compared with control group (p &lt, 0.05), suggesting that LSA alleviated the damage and permeability of weaning piglets. LSA significantly increased superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels, but decreased malondialdehyde (MDA) level, indicating that LSA significantly enhanced the antioxidant capacity and reduced oxidative stress in weaning piglets. RT-PCR results showed that LSA significantly increased GSH-Px1, GSH-Px2, SOD-1, SOD-2, CAT, Nrf2, HO-1, and NQO1 gene expression (p &lt, 0.05). Western blot analysis revealed that LSA activated the Nrf2 signaling pathway by downregulating the expression of Keap1 and upregulating the expression of Nrf2 to protect intestinal mucosa against oxidative stress. Collectively, LSA reduced intestinal mucosal damage induced by oxidative stress via Nrf2-Keap1 pathway in weaning stress of infants.