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Boron doped emitters prepared by thermal diffusion using boron trichloride (BCl3) have been adopted in N-type Tunnel Oxide Passivated Contact (TOPCon) silicon solar cells. In order to establish a proper diffusion process of p + emitter that matches to TOPCon solar cells fabrication, the influence of diffusion pressure, pre-deposition O2 flow rate and drive-in O2 flow rate on the doping profiles, sheet resistance, BSG thickness as well as the sheet resistance uniformity are carefully investigated. In addition, the impact of BSG thickness on the surface morphology and optical properties of the TOPCon cells are studied. The experimental results indicate that good uniformity of p + emitter can be obtained at low pressure (300 mbar) with acceptable sheet resistance. In addition, a p + emitter with thick BSG (> 50 nm) layer is very necessary, which can effectively protect the underneath emitter during the removal process of the wrap-around poly-Si. Finally, high efficiency over 22% is obtained for 244.32 cm2 n-type TOPCon solar cells based on the boron diffused emitter with the sheet resistance 70–90 ohm/sq., BSG thickness ~ 100 nm.

Fluorochemicals are a widely distributed class of compounds and have been utilized across a wide range of industries for decades. Given the environmental toxicity and adverse health threats of some fluorochemicals, the development of new methods for their decomposition is significant to public health. However, the carbon–fluorine (C–F) bond is among the most chemically robust bonds; consequently, the degradation of fluorinated hydrocarbons is exceptionally difficult. Here, metalloenzymes that catalyze the cleavage of this chemically challenging bond are reviewed. These enzymes include histidine-ligated heme-dependent dehaloperoxidase and tyrosine hydroxylase, thiolate-ligated heme-dependent cytochrome P450, and four nonheme oxygenases, namely, tetrahydrobiopterin-dependent aromatic amino acid hydroxylase, 2-oxoglutarate-dependent hydroxylase, Rieske dioxygenase, and thiol dioxygenase. While much of the literature regarding the aforementioned enzymes highlights their ability to catalyze C–H bond activation and functionalization, in many cases, the C–F bond cleavage has been shown to occur on fluorinated substrates. A copper-dependent laccase-mediated system representing an unnatural radical defluorination approach is also described. Detailed discussions on the structure–function relationships and catalytic mechanisms provide insights into biocatalytic defluorination, which may inspire drug design considerations and environmental remediation of halogenated contaminants.

Cimifugin is an important component of chromones in the dry roots of Saposhikovia divaricata for treating inflammatory diseases. However, the possible effect of cimifugin in psoriasis needs further investigation. This current work was designed to evaluate the effects of cimifugin in psoriasis in vivo and in vitro, and unravel the underlying molecular mechanism. Here, we used imiquimod (IMQ) or tumor necrosis factor (TNF)-α to induce a psoriasis-like model in mice or keratinocytes. Obviously, the results showed that cimifugin reduced epidermal hyperplasia, psoriasis area severity index (PASI) scores, ear thickness and histological psoriasiform lesions in IMQ-induced mice. The decreased levels of reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), and the accumulation of malondialdehyde (MDA) in skin tissues by IMQ were attenuated by cimifugin. Furthermore, it was observed that cimifugin effectively reversed IMQ-induced up-regulation of proinflammatory cytokines, including TNF-α, IL-6, IL-1β, IL-17A, and IL-22. Mechanically, we noticed that cimifugin inhibited IMQ-activated phosphorylation of NF-κB (IκB and p65) and MAPK (JNK, ERK, and p38) signaling pathways. Similar alterations for oxidative stress and inflammation parameters were also detected in TNF-α-treated HaCaT cells. In addition, cimifugin-induced down-regulation of ICAM-1 were observed in TNF-α-treated cells. Altogether, our findings suggest that cimifugin protects against oxidative stress and inflammation in psoriasis-like pathogenesis by inactivating NF-κB/MAPK signaling pathway, which may develop a novel and effective drug for the therapy of psoriasis.

Cysteamine dioxygenase (ADO) has been reported to exhibit two distinct biological functions with a nonheme iron center. It catalyzes oxidation of both cysteamine in sulfur metabolism and N-terminal cysteine-containing proteins or peptides, such as regulator of G protein signaling 5 (RGS5). It thereby preserves oxygen homeostasis in a variety of physiological processes. However, little is known about its catalytic center and how it interacts with these two types of primary substrates in addition to O(2). Here, using electron paramagnetic resonance (EPR), Mössbauer, and UV-visible spectroscopies, we explored the binding mode of cysteamine and RGS5 to human and mouse ADO proteins in their physiologically relevant ferrous form. This characterization revealed that in the presence of nitric oxide as a spin probe and oxygen surrogate, both the small molecule and the peptide substrates coordinate the iron center with their free thiols in a monodentate binding mode, in sharp contrast to binding behaviors observed in other thiol dioxygenases. We observed a substrate-bound B-type dinitrosyl iron center complex in ADO, suggesting the possibility of dioxygen binding to the iron ion in a side-on mode. Moreover, we observed substrate-mediated reduction of the iron center from ferric to the ferrous oxidation state. Subsequent MS analysis indicated corresponding disulfide formation of the substrates, suggesting that the presence of the substrate could reactivate ADO to defend against oxidative stress. The findings of this work contribute to the understanding of the substrate interaction in ADO and fill a gap in our knowledge of the substrate specificity of thiol dioxygenases.

A 20-W all-fiber oscillator operating near 980 nm is demonstrated with a commercially-available double-cladding Yb-doped fiber. 20.1-W output power is eventually obtained with the slope efficiency of 16.1% and the center wavelength around 978 nm.

Smelter Grade Alumina (SGA) is used as the raw material in primary aluminum electrolysis. The current aluminum reduction technology has strict requirement to the particle size distribution of SGA during the whole production process. This paper investigated the particle size parameters of industrial SGA on the Chinese market. The tested parameters include the particle size distribution and the attrition index of 14 kinds of fresh SGA and 7 secondary SGA, respectively. The relationship between the particle size distribution and the attrition index is discussed, and the influence of dry scrubbing system on the alumina particle size is considered as well. At last, this paper tries to propose an evaluation criterion based on the combination of particle size distribution and attrition index.

Based on Schwarz–Christoffel mapping, this paper presents a fast analytical method to analyze the electromagnetic force of eccentric axial flux permanent magnet machines, considering static, dynamic, and mixed eccentricities. A quasi-3D model of an axial flux permanent magnet machine is established, and the magnetic field is obtained by Schwarz–Christoffel mapping. The electromagnetic force density is obtained by the Maxwell stress tensor method, and the electromagnetic force density is used to characterize the variation of electromagnetic force. The distribution law of electromagnetic force is investigated. The calculated results are verified by the finite element method, which has shown that the method in this paper can be widely used in the analysis of axial flux permanent magnet machines.

During development, the mouse brain is progressively divided into functionally distinct compartments. Numerous neuronal and glial cell types are subsequently generated in response to various inductive signals. Each cell expresses a unique combination of genes encoding proteins from transcription factors to neurotransmitters that define its role in brain function. To understand these important and highly sophisticated processes, it is critical to accurately locate the various proteins and cells that produce them. In this chapter, we introduce the techniques of Immunohistochemistry, which detects the localization of specific proteins, and RNA in situ hybridization, which enables the visualization of specific mRNAs.

A combined control strategy of photovoltaic grid-connection, reactive power compensation and energy storage was proposed for a novel energy storage quasi-z source inverter. According to the different state of the battery, the system applies different control schemes. Based on the control strategy of the battery under normal conditions, this paper analyzes and discusses the unit power facto grid-connected while ensuring the maximum utilization of photovoltaic cell energy efficiency and enhancing the stability of grid-connected power, and compensates the load with reactive power. Finally, simulation and experiment verify the effectiveness and correctness of the proposed strategy.

Treatment of both [CoCl(tBuPNP)] and [NiCl(tBuPNP)] (tBuPNP = anion of 2,5-bis((di-tert-butylphosphino)methyl)pyrrole) with one equivalent of benzoquinone affords the corresponding chloride complexes containing a dehydrogenated PNP ligand, tBudPNP (tBudPNP = anion of 2,5-bis((di-tert-butylphosphino)methylene)-2,5-dihydropyrrole). Dehydrogenation of PNP to dPNP results in minimal change to steric profile of the ligand but has important consequences for the resulting redox potentials of the metal complexes resulting in the ability to isolate both [CoH(tBudPNP)] and [CoEt(tBudPNP)], which are more challenging (hydride) or not possible (ethyl) to prepare with the parent PNP ligand. Electrochemical measurements with both the Co and Ni dPNP species demonstrate a substantial shift in redox potentials for both the M(II/III) and M(II/I) couples. In the case of the former, oxidation to trivalent Co was found to be reversible, and subsequent reaction with AgSbF6 afforded a rare example of a square-planar Co(III) species. Corresponding reduction of [CoCl(tBudPNP)] with KC8 produced the diamagnetic Co(I) species, [Co(N2)(tBudPNP)]. Further reduction of the Co(I) complex was found to generate a rare pincer-based π-radical anion that demonstrated well-resolved EPR features to the four hydrogen atoms and lone nitrogen atom of the ligand with minor contributions from cobalt and coordinated N2. Changes in the electronic character of the PNP ligand upon dehydrogenation are proposed to result from loss of aromaticity in the pyrrole ligand resulting in a more reducing central amido donor. DFT calculations on the Co(II) complexes were performed to shed further insight into the electronic structure of the pincer complexes.

3-Hydroxyanthranilate 3,4-dioxygenase (HAO) is an iron-dependent protein that activates O(2) and inserts both oxygen atoms into 3-hydroxyanthranilate (3-HAA). An intriguing question is how HAO can rapidly bind O(2), even though local O(2) concentrations and diffusion rates are relatively low. Here, a close inspection of the HAO structures revealed that substrate- and inhibitor-bound structures exhibit a closed conformation with three hydrophobic loop regions moving toward the catalytic iron center, whereas the ligand-free structure is open. We hypothesized that these loop movements enhance O(2) binding to the binary complex of HAO and 3-HAA. We found that the carboxyl end of 3-HAA triggers changes in two loop regions and that the third loop movement appears to be driven by an H-bond interaction between Asn(27) and Ile(142). Mutational analyses revealed that N27A, I142A, and I142P variants cannot form a closed conformation, and steady-state kinetic assays indicated that these variants have a substantially higher K(m) for O(2) than WT HAO. This observation suggested enhanced hydrophobicity at the iron center resulting from the concerted loop movements after the binding of the primary substrate, which is hydrophilic. Given that O(2) is nonpolar, the increased hydrophobicity at the iron center of the binary complex appears to be essential for rapid O(2) binding and activation, explaining the reason for the 3-HAA–induced loop movements. Because substrate binding-induced open-to-closed conformational changes are common, the results reported here may help further our understanding of how oxygen is enriched in nonheme iron-dependent dioxygenases.

Cysteine dioxygenase (CDO) plays an essential role in sulfur metabolism by regulating homeostatic levels of cysteine. Human CDO contains a post-translationally generated Cys93-Tyr157 cross-linked cofactor. Here, we investigated this Cys-Tyr cross-linking by incorporating unnatural tyrosines in place of Tyr157 via a genetic method. The catalytically active variants were obtained with a thioether bond between Cys93 and the halogen-substituted Tyr157, and we determined the crystal structures of both wild-type and engineered CDO variants in the purely uncross-linked form and with a mature cofactor. Along with mass spectrometry and 19F NMR, these data indicated that the enzyme could catalyze oxidative C-F or C-Cl bond cleavage, resulting in a substantial conformational change of both Cys93 and Tyr157 during cofactor assembly. These findings provide insights into the mechanism of Cys-Tyr cofactor biogenesis and may aid the development of bioinspired aromatic carbon-halogen bond activation.

Cysteamine dioxygenase (ADO) is a thiol dioxygenase whose study has been stagnated by the ambiguity as to whether or not it possesses an anticipated protein-derived cofactor. Reported herein is the discovery and elucidation of a Cys-Tyr cofactor in human ADO, crosslinked between Cys220 and Tyr222 through a thioether (C-S) bond. By genetically incorporating an unnatural amino acid, 3,5-difluoro-tyrosine (F2 -Tyr), specifically into Tyr222 of human ADO, an autocatalytic oxidative carbon-fluorine bond activation and fluoride release were identified by mass spectrometry and 19 F NMR spectroscopy. These results suggest that the cofactor biogenesis is executed by a powerful oxidant during an autocatalytic process. Unlike that of cysteine dioxygenase, the crosslinking results in a minimal structural change of the protein and it is not detectable by routine low-resolution techniques. Finally, a new sequence motif, C-X-Y-Y(F), is proposed for identifying the Cys-Tyr crosslink.

The kynurenine pathway is the primary route for l-tryptophan degradation in mammals. Intermediates and side products of this pathway are involved in immune response and neurodegenerative diseases. This makes the study of enzymes, especially those from mammalian sources, of the kynurenine pathway worthwhile. Recent studies on a bacterial version of an enzyme of this pathway, 2-aminomuconate semialdehyde (2-AMS) dehydrogenase (AMSDH), have provided a detailed understanding of the catalytic mechanism and identified residues conserved for muconate semialdehyde recognition and activation. Findings from the bacterial enzyme have prompted the reconsideration of the function of a previously identified human aldehyde dehydrogenase, ALDH8A1 (or ALDH12), which was annotated as a retinal dehydrogenase based on its ability to preferentially oxidize 9-cis-retinal over trans-retinal. Here, we provide compelling bioinformatics and experimental evidence that human ALDH8A1 should be reassigned to the missing 2-AMS dehydrogenase of the kynurenine metabolic pathway. For the first time, the product of the semialdehyde oxidation by AMSDH is also revealed by NMR and high-resolution MS. We found that ALDH8A1 catalyzes the NAD(+)-dependent oxidation of 2-AMS with a catalytic efficiency equivalent to that of AMSDH from the bacterium Pseudomonas fluorescens. Substitution of active-site residues required for substrate recognition, binding, and isomerization in the bacterial enzyme resulted in human ALDH8A1 variants with 160-fold increased K(m) or no detectable activity. In conclusion, this molecular study establishes an additional enzymatic step in an important human pathway for tryptophan catabolism.

Tryptophan-based free radicals have been implicated in a myriad of catalytic and electron transfer reactions in biology. However, very few of them have been trapped so that biophysical characterizations can be performed in a high-precision context. In this work, tryptophan derivative-based radicals were studied by high-frequency/high-field electron paramagnetic resonance (HFEPR) and quantum chemical calculations. Radicals were generated at liquid nitrogen temperature with a photocatalyst, sacrificial oxidant, and violet laser. The precise g-anisotropies of l- and d-tryptophan, 5-hydroxytryptophan, 5-methoxytryptophan, 5-fluorotryptophan, and 7-hydroxytryptophan were measured directly by HFEPR. Quantum chemical calculations were conducted to predict both neutral and cationic radical spectra for comparison with the experimental data. The results indicate that under the experimental conditions, all radicals formed were cationic. Spin densities of the radicals were also calculated. The various line patterns a...

An aluminum-containing solvate ionic liquid, DMI–AlCl3 (1 M)–MgCl2 (0.5 M) was used as the electrolyte for magnesium electrodeposition. The results of Raman spectroscopy and 27Al nuclear magnetic resonance spectroscopy indicated the existence of aluminum-containing [AlCl4]- and [AlCl2(DMI)4]+ in the DMI–AlCl3 (1 M) system. When 0.5 M MgCl2 was added to DMI–AlCl3, the Mg(II) species was [MgCl(DMI)n]+. X-ray diffraction analysis indicated that a coating of Al3Mg2 can be prepared by potentiostatic electrodeposition at −1.45 V (vs. Al) at 323 K on a copper sheet cathode.

In this study, Al–Si alloy, a precursor of the solar-grade silicon, was prepared via the aluminothermic reduction–molten salt electrolysis of SiO2 in KF–AlF3 molten salt by employing liquid aluminum as the working cathode. The reaction mechanism of the aluminothermic reduction of SiO2 in KF–AlF3 molten salt at 750 °C was determined by thermogravimetry–differential scanning calorimetry. The reaction rate equation for the aluminothermic reduction of SiO2 in KF–AlF3 molten salt was: d α dt = 7.156 × 10 24 e − 4.688 × 10 5 RT ( 1 − α ) 1.734 . In 49.4 wt.% KF–47.6 wt.% AlF3–3 wt.% SiO2 molten salt at 750 °C, the Si content in the Al–Si alloy obtained by the aluminothermic reduction–molten salt electrolysis of SiO2 was 24.53 wt.%. Compared with solely aluminothermic reduction of SiO2, the current efficiency in the process of the aluminothermic reduction–molten salt electrolysis of SiO2 was evaluated. The results reveal that the Al–Si alloy is predominantly prepared in the aluminothermic reduction step, while supplemented by electrolysis. The calculated Faradic current efficiency of the proposed aluminothermic reduction–molten salt electrolysis process was 28.4%.

In this paper, a 500-W-level all-fiber amplifier operating near 980 nm is demonstrated firstly, to the best of our knowledge. The amplifier is fabricated with a 105/250-μm core/cladding-diameter double-cladding Yb-doped fiber (DCYF). By optimizing the length of DCYF, the record 556-W output power and 50.5% slope efficiency are obtained with a 1.85-W seed light, and about 30.9 dB peak-to-peak suppression of 1030-nm amplified spontaneous emission (ASE) is realized. Furthermore, the strong in-band ASE is also observed in experiment, which limits the power up-scaling of the fiber amplifier. By analyzing the origin of the in-band ASE, it is revealed that optimizing the seed light should be beneficial to the suppression of in-band ASE. Besides, the beam quality is measured at the maximum output power and the M2 factor is about 23.6. The experimental study should be able to provide significant guidance for understanding and designing the high-power three-level fiber lasers and amplifiers.

A membrane bioreactor (MBR) was used for treating biological aerated filter effluent in a municipal wastewater plant, and chemical phosphorus removal was accomplished in the MBR. The results showed that ferric chloride of 20 mg/L and aluminum sulfate of 30 mg/L were the optimal dosages for total phosphorus (TP) removal, and the TP removal efficiency was over 80%. In long-term continuous operations, both ferric chloride and aluminum sulfate effectively mitigated membrane fouling, with the corresponding growth rate of transmembrane pressure decreased to 0.08 and 0.067 kPa/d, respectively. Sludge particle sizes analysis demonstrated that the decrease of particle sizes lower than 50 μm was the main reason for membrane fouling control. Simultaneously, the proteins and polysaccharide (PS) concentrations in the MBR supernatant were analyzed, and the PS concentration significantly decreased to 2.02 mg/L at aluminum sulfate of 30 mg/L, indicating the flocculation of aluminum sulfate on PS was the main reason for mitigation of membrane fouling.

Primary cilia are essential for normal development and tissue homeostasis, but the mechanisms that remodel the centriole to promote cilia initiation are not well understood. Agbu et al. report that mouse RSG1, a small GTPase, regulates a late step in cilia initiation, downstream of TTBK2 and the CPLANE protein INTU., Primary cilia, which are essential for normal development and tissue homeostasis, are extensions of the mother centriole, but the mechanisms that remodel the centriole to promote cilia initiation are poorly understood. Here we show that mouse embryos that lack the small guanosine triphosphatase RSG1 die at embryonic day 12.5, with developmental abnormalities characteristic of decreased cilia-dependent Hedgehog signaling. Rsg1 mutant embryos have fewer primary cilia than wild-type embryos, but the cilia that form are of normal length and traffic Hedgehog pathway proteins within the cilium correctly. Rsg1 mother centrioles recruit proteins required for cilia initiation and dock onto ciliary vesicles, but axonemal microtubules fail to elongate normally. RSG1 localizes to the mother centriole in a process that depends on tau tubulin kinase 2 (TTBK2), the CPLANE complex protein Inturned (INTU), and its own GTPase activity. The data suggest a specific role for RSG1 in the final maturation of the mother centriole and ciliary vesicle that allows extension of the ciliary axoneme.

In this work Cu2O microcrystals with various morphologies including octahedrons, cubes and hollow spheres were employed as the antimicrobial for the devitalization of Escherichia coli (E. coli). It was found that during the devitalization of E. coli, Cu2O microcrystals with various shapes presented similar change trend and finally was converted into flowerlike microstructures constructed by abundant nanosheets. Also, the shape change always started from {1 0 0} planes.

In this work, urea and 1-butyl-3-methylimidazolium chloride (urea-BMIC) deep eutectic solutions were used as electrolytes for electrodeposition of lead from lead oxide. The electrochemical behavior of Pb (II) ions was investigated by cyclic voltammetry, chronopotentiometry, and chronoamperometry techniques at 353–373 K. Cyclic voltammograms and chronopotentiograms indicate that the reduction of Pb (II) ions to Pb is a diffusion-controlled quasi-reversible process and it proceeds via one step two-electron transfer process at −0.38 V (vs. Ag). The diffusion coefficient of Pb (II) ions increases from 3.22 × 10 −8 cm 2 s −1 to 1.49 × 10 −7 cm 2 s −1 as temperature increases from 353 K to 373 K. The activation energy for diffusion is determined to be 83.93 kJ mol −1 . In addition, results from chronoamperometry show that lead deposition involves in a three-dimensional instantaneous nucleation and diffusion-controlled growth. On the other hand, the electrodeposit on a Cu substrate was pure Pb as confirmed by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Scanning electron microscopy (SEM) image indicated that a uniform, dense, and non-dendritic coating with grain size of 3 μm in diameter was prepared by potentiostatic electrolysis at −0.4 V (vs. Ag). The optimized current efficiency (96.17%) and energy consumption (0.11 kWh kg −1 ) was obtained by potentiostatic electrolysis at −0.4 V (vs. Ag) and 373 K from urea-BMIC deep eutectic solutions containing 0.072 mol dm −3 PbO.

In this paper, a cost-effective 50-W-level all-fiber oscillator operating near 980 nm is demonstrated with the 20-μm core-diameter double-cladding Yb-doped fiber (DCYF) firstly, to the best of our knowledge. By using the 15-degree angle-cleaved output fiber end-facet, the record 54.8-W output power is obtained with the slope efficiency about 15.6%. It is revealed that increasing the cleaved angle (or suppressing the optical feedback) of output fiber end-facet should be an effective way to improve the performance of the fiber oscillator. Then, by optimizing the length of DCYF, the slope efficiency is slightly improved to 15.8% because of better suppression of the amplified spontaneous emission (ASE) around 1030 nm. It is also found that the effect of pumping scheme is negligible on the performance of the fiber oscillator. The beam quality is measured and the M2 factor is about 2.5. Better beam quality can be expected by lowering the numerical aperture (NA) of the active fiber core. The all-fiber oscillator can provide a well solution for the high-power core-pump source.

Objective The purpose of this study is to investigate whether aspirin improves the prognosis of breast cancer patients by meta analysis. Methods Searched PubMed, EMBASE, and other databases for literature on the relationship between aspirin use and breast cancer prognosis, with the deadline of October 2019. The related results of all-cause death, breast cancer-specific death, and breast cancer recurrence/metastasis were extracted to combine the effect amount. The sensitivity analysis and published bias analysis were carried out for the included data. Stata12.0 software was used to complete all statistical analysis. Results A total of 13 papers were included in the study, including 142,644 breast cancer patients. The results of meta-analysis showed that patients who took aspirin were associated with lower breast cancer-specific death (HR = 0.69, 95% CI = 0.61-0.76), all-cause death (HR = 0.78, 95% CI = 0.71-0.84), and risk of recurrence/metastasis (HR = 0.91, 95% CI: 0.82-1.00). Conclusions Aspirin use may improve all-cause mortality, specific mortality, and risk of recurrence/metastasis in patients with breast cancer.

Few articles are reported for the simultaneous separation and sensitive detection of the kynurenine pathway (KP) metabolites. This work describes a capillary electrochromatography-mass spectrometry (CEC-MS) method using acrylamido-2-methyl-1-propanesulfonic acid (AMPS) functionalized stationary phase. The AMPS column was prepared by first performing silanization of bare silica with gamma-maps, followed by polymerization with AMPS. The CEC-MS/MS methods were established for six upstream and three downstream KP metabolites. The simultaneous separation of all nine KP metabolites is achieved without derivatization for the first time in the open literature. Numerous parameters such as pH and the concentration of background electrolyte, the concentration of the polymerizable AMPS monomer, column length, field strength, and internal pressure were all tested to optimize the separation of multiple KP metabolites. A baseline separation of six upstream metabolites, namely tryptophan (TRP), kynurenine (KYN), 3-hydroxykynurenine (HKYN), kynurenic acid (KA), anthranilic acid (AA), and xanthurenic acid (XA), was possible at pH 9.25 within 26 min. Separation of six downstream and related metabolites, namely: tryptamine (TRPM), hydroxy‑tryptophan (HTRP), hydroxyindole-3 acetic acid (HIAA), 3-hydroxyanthranilic acid (3-HAA), picolinic acid (PA), and quinolinic acid (QA), was achieved at pH 9.75 in 30 min. However, the challenging simultaneous separation of all nine KP metabolites was only accomplished by increasing the column length and simultaneous application of internal pressure and voltage in 114 min. Quantitation of KP metabolites in commercial human plasma was carried out, and endogenous concentration of five KP metabolites was validated. The experimental limit of quantitation ranges from 100 to 10,000 nM (S/N = 8–832, respectively), whereas the experimental limit of detection ranges from 31 to 1000 nM (S/N = 2–16, respectively). Levels of five major KP metabolites, namely TRP, KYN, KA, AA, and QA, and their ratios in patient plasma samples previously screened for inflammatory biomarkers [C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α)] was measured. Pairs of the level of metabolites with significant positive correlation were statistically evaluated.

Little is known about bifurcations in two-dimensional (2D) differential systems from the viewpoint of Kosambi–Cartan–Chern (KCC) theory. Based on the KCC geometric invariants, three types of static bifurcations in 2D differential systems, i.e. saddle-node bifurcation, transcritical bifurcation, and pitchfork bifurcation, are discussed in this paper. The dynamics far from fixed points of the systems generating bifurcations are characterized by the deviation curvature and nonlinear connection. In the nonequilibrium region, the nonlinear stability of systems is not simple but involves alternation between stability and instability, even though systems are invariably Jacobi-unstable. The results also indicate that the dynamics in the nonequilibrium region are node-like for three typical static bifurcations.

This paper presents a thorough review of various technologies to obtain titanium and its alloys and their discussion concerning their merits and demerits. Titanium and its alloys are ideal advanced structural materials because of their excellent properties such as high corrosion resistance, exceptional strength-to-weight ratio, bio-compatible, non-magnetic and mechanical properties. As a result, such materials are served extensively for several engineering applications that include wind turbines, auto industries, biomedical implants, aerospace industry, marine structures, and many others. However, the low yield and higher cost production of the current employed energy-intensive Kroll process restricts the widespread use of titanium and its alloys. Numerous alternative extraction processes have been developed during the last few decades to produce titanium and its alloys in a more accessible and cost-effective way. Amid growing demand for titanium in the market, it is necessary to consider the impact of technological innovations that can reduce titanium production cost. Recent research and developments on the electrochemical reduction method of titanium production from molten salts or ionic liquids have shown promising results. This paper reviews the developments on titanium production and its alloys by various techniques, including but not limited to molten salt electrolysis processes, such as the FFC-Cambridge process, the OS process, the USTB process, and ionic-liquid electrolysis.

Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13-1014 ng g-1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048-3.3 ng g-1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8-153 ng g-1 and 0.43-15 ng g-1, respectively. DP was another primary FR, with concentrations of 0.57-146 ng g-1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5-17 pg TEQ g-1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.

In-situ utilization of lunar resources for the production of metals and oxygen is essential for lunar exploration. The main emphasis of this article is on a candidate approach that combined aluminothermic reduction and electrolysis process in cryolite molten salts to produce both Al-based alloy and oxygen from lunar soil simulants. The influences of reductant amount and reaction time on the aluminothermic reduction of coal fly ash in cryolite melts at 1233 K (960 °C) were studied. The results obtained by XRF, XRD, SEM and EDS analysis show that the products mainly contain Al, Si, Fe, and little Ti, while the main phases of the products are Al and Si. With the increase of reaction time, the content of Si in alloy products increases from 4.43 wt% to 7.47 wt%. In addition, the remaining alumina-rich cryolite melts was electrolyzed at 1233 K (960 °C) using 56 wt%Fe-44 wt%Ni alloy inert anode. The cathode product obtained by galvanostatic electrolysis for 4 h was characterized, and the results showed that the phase composition of the cathode product was pure Al, while the highest aluminum content in the cathode product is 99.431 wt%. Besides, the outlet gas at the anode during electrolysis is pure oxygen according to the analysis of gas chromatography.

CYP121, the cytochrome P450 enzyme in Mycobacterium tuberculosis that catalyzes a single intramolecular C–C cross-linking reaction in the biosynthesis of mycocyclosin, is crucial for the viability of this pathogen. This C–C coupling reaction represents an expansion of the activities carried out by P450 enzymes distinct from oxygen insertion. Although the traditional mechanism for P450 enzymes has been well studied, it is unclear whether CYP121 follows the general P450 mechanism or uses a different catalytic strategy for generating an iron-bound oxidant. To gain mechanistic insight into the CYP121-catalyzed reaction, we tested the peroxide shunt pathway by using rapid kinetic techniques to monitor the enzyme activity with its substrate dicyclotyrosine (cYY) and observed the formation of the cross-linked product mycocyclosin by LC-MS. In stopped-flow experiments, we observed that cYY binding to CYP121 proceeds in a two-step process, and EPR spectroscopy indicates that the binding induces active site reorganization and uniformity. Using rapid freeze-quenching EPR, we observed the formation of a high-spin intermediate upon the addition of peracetic acid to the enzyme–substrate complex. This intermediate exhibits a high-spin (S = 5/2) signal with g values of 2.00, 5.77, and 6.87. Likewise, iodosylbenzene could also produce mycocyclosin, implicating compound I as the initial oxidizing species. Moreover, we also demonstrated that CYP121 performs a standard peroxidase type of reaction by observing substrate-based radicals. On the basis of these results, we propose plausible free radical–based mechanisms for the C–C bond coupling reaction.

Inturned (INTU), a cilia and planar polarity effector, performs prominent ciliogenic functions during morphogenesis, such as in the skin. INTU is expressed in adult tissues but its role in tissue maintenance is unknown. Here, we report that the expression of the INTU gene is aberrantly elevated in human basal cell carcinoma (BCC), coinciding with increased primary cilia formation and activated hedgehog (Hh) signaling. Disrupting Intu in an oncogenic mutant Smo (SmoM2)-driven BCC mouse model prevented the formation of BCC through suppressing primary cilia formation and Hh signaling, suggesting that Intu performs a permissive role during BCC formation. INTU is essential for intraflagellar transport A complex assembly during ciliogenesis. To further determine whether Intu is directly involved in the activation of Hh signaling downstream of ciliogenesis, we examined the Hh signaling pathway in mouse embryonic fibroblasts, which readily responds to the Hh pathway activation. Depleting Intu blocked Smo agonist-induced Hh pathway activation, whereas the expression of Gli2ΔN, a constitutively active Gli2, restored Hh pathway activation in Intu-deficient cells, suggesting that INTU functions upstream of Gli2 activation. In contrast, overexpressing Intu did not promote ciliogenesis or Hh signaling. Taken together, data obtained from this study suggest that INTU is indispensable during BCC tumorigenesis and that its aberrant upregulation is likely a prerequisite for primary cilia formation during Hh-dependent tumorigenesis.

Multifunctional Fe3O4@resorcinol–formaldehyde resin/Cu2O composite microstructures (denoted as Fe3O4@RF/Cu2O microstructures) were successfully constructed via a simple wet chemical route that has not been reported so far in the literature. The as-obtained Fe3O4@RF/Cu2O microstructures were characterized using field-emission scanning electron microscopy, (high-resolution) transmission electron microscopy, selected-area electron diffraction, X-ray diffraction, and X-ray energy dispersive spectroscopy. The investigations showed that the as-obtained microstructures presented not only excellent antibacterial activity to Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) but also highly efficient catalytic ability for the reduction of 4-nitrophenol (4-NP) in a solution with excess NaBH4. Owing to the presence of Fe3O4, the antibacterial reagent and the catalyst could be readily collected from the mixed systems under the assistance of an external magnetic field. It was ...

In this study, we dissolved PbO in a new electrolyte urea/1-ethyl-3-methylimidazolium chloride (EMIC) and electrochemically extracted Pb. The electrochemical behavior of lead was investigated using chronoamperometric and cyclic voltammetric techniques. The cyclic voltammograms illustrated that lead reduction is quasi-reversible and follows a single-step, two-electron transfer process. The chronoamperometric experiments showed that lead reduction in the PbO–urea/EMIC system follows a 3D instantaneous nucleation and a diffusion-controlled growth at 353 K. The diffusion coefficient was 1.67 × 10−8 cm2 s−1. The effect of temperature on the electrochemical behavior of lead was investigated. Results showed that electrode reaction becomes more reversible as temperature increases from 343 to 373 K. The diffusion coefficients increase with increasing temperature and obey the Arrhenius' law. The activation energy is estimated to be 38 kJ mol−1. Electrodeposition experiments were conducted on tungsten substrates at different negative potentials and various temperatures. Scanning electron microscopy (SEM) images of electrodeposits showed that the Pb particles became smaller and are more densely distributed at more negative potentials and higher temperatures. The obtained electrodeposits were metallic lead, as verified by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS).

Dynamic characteristic analysis of a two-stand reversible cold rolling mill in the startup process was carried out. The delay algorithm of the interstand thickness was proposed. A new method combined with the accelerated secant and the tangent methods was established to solve the simultaneous equations. The thickness and interstand tension transition processes with different static tension establishing processes were analyzed. Both mills were operated under constant rolling force control mode in the above process. The results show that the strip thickness in the rolling gap reduces in the static mill screwdown process. The entry stand runs inversely to establish the static interstand tension. This area becomes an abnormal thickness reduction area of the incoming strip. It results in several abnormal interstand tension increases in the subsequent startup process. The tension increase leads to an impact force on the strip that is the main reason of the strip breakage in the startup process. So the static tension establishing process was optimized, and the interstand tension fluctuation and the strip breakage accidents both reduced significantly. The results are beneficial to the startup process of the two-stand reversible cold rolling mill.

Indian Hedgehog (Ihh) regulates chondrocyte and osteoblast differentiation through the Glioma-associated oncogene homolog (Gli) transcription factors. Previous in vitro studies suggested that Speckle-type POZ protein (Spop), part of the Cullin-3 (Cul3) ubiquitin ligase complex, targets Gli2 and Gli3 for degradation and negatively regulates Hedgehog (Hh) signaling. In this study, we found defects in chondrocyte and osteoblast differentiation in Spop-null mutant mice. Strikingly, both the full-length and repressor forms of Gli3, but not Gli2, were up-regulated in Spop mutants, and Ihh target genes Patched 1 (Ptch1) and parathyroid hormone-like peptide (Pthlh) were down-regulated, indicating compromised Hh signaling. Consistent with this finding, reducing Gli3 dosage greatly rescued the Spop mutant skeletal defects. We further show that Spop directly targets the Gli3 repressor for ubiquitination and degradation. Finally, we demonstrate in a conditional mutant that loss of Spop results in brachydactyly and osteopenia, which can be rescued by reducing the dosage of Gli3. In summary, Spop is an important positive regulator of Ihh signaling and skeletal development.

Aldehyde dehydrogenase typically performs oxidation of aldehydes to their corresponding carboxylic acid while reducing NAD(P)+ to NAD(P)H via covalent catalysis mediated by an active-site cysteine residue. One member of this superfamily, the enzyme 2-aminomuconate-6-semialdehyde dehydrogenase (AMSDH), is a component of the kynurenine pathway, which catabolizes tryptophan in mammals and certain bacteria. AMSDH catalyzes the NAD+-dependent oxidation of 2-aminomuconate semialdehyde to 2-aminomuconate. We recently determined the first crystal structure of AMSDH and several catalytic cycle intermediates. A conserved asparagine in the oxyanion hole, Asn-169, is found to be H-bonded to substrate-derived intermediates in the active site of AMSDH during catalysis, including both the covalently bound thiohemiacetal and thioacyl intermediates. To better interrogate the significance of the hydrogen bond provided by Asn-169 to the reaction mechanism of AMSDH, we created Ala, Ser, Asp, and Gln mutants and studied them using biochemical, kinetic, crystallographic, and computational studies. The in crystallo chemical reaction of the primary substrate with the co-crystalized complex of the N169D mutant and NAD+ led to the successful trapping of a new catalytic intermediate that was not previously seen. The structural and computational data are consistent with a substrate imine/enol tautomer intermediate being formed prior to the formation of the covalent bond between the substrate and the active-site cysteine. Thus, AMSDH surprisingly includes an isomerization process within its known catalytic mechanism. These data establish a hidden intrinsic isomerization activity of the dehydrogenase and allow us to propose a pitcher-catcher type of catalytic mechanism for the isomerization.

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease, characterized by overactive inflammation and aberrant activation of lymphocytes. Chemokine C-X-C motif ligand 10 (CXCL10) has an important role in the initiation and deterioration of SLE. However, the expression levels of CXCL10 mRNA in T-helper (Th) cells and B lymphocytes from SLE patients have remained elusive. In the present study, a Bioinformatics analysis of differentially expressed gene (DEG) profiles obtained from RNA sequencing data for three matched samples was performed to explore the hub genes, mainly through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes and protein-protein interaction analysis. Furthermore, the expression of CXCL10 in peripheral blood mononuclear cells (PBMCs), CD4+ Th cells and CD19+ B cells of 108 subjects, including 66 SLE patients and 42 healthy controls, was confirmed by reverse transcription-quantitative PCR. In addition, 4 single-nucleotide polymorphism (SNP) loci in the 3′-untranslated region of CXCL10 were assessed using the Snapshot SNP genotyping assay. A total of 152 clustered DEGs mainly accumulated in immune-associated GO terms and interferon-associated pathways were identified. The expression of CXCL10, one of the central genes in the interaction network cluster (the degree of interaction, MCODE score=28.414), was 6.27-fold higher in SLE patients compared with control patients. Furthermore, CXCL10 mRNA was confirmed to be elevated in PBMCs and CD19+ B cells of patients with SLE (P

In order to solve the disadvantages of long start-up time and demagnetization of the traditional permanent magnetic actuators, this paper presents a high reliability and controllable motor actuator without permanent magnet, which including driving motor and its control circuit. The proposed driving motor is similar to the switched reluctance motor which has the advantages of small rotational inertia and fast start-up. The difference is that there is an auxiliary coil which is placed between the two-stator sets and can be energized by controllable DC current to adjust the air-gap flux density that the output torque and the velocity of movable contact is easier to control. Furthermore, a prototype of the novel motor actuator has been developed according to the analysis and calculation results of dynamic characteristics of 40.5-kV Vacuum Circuit Breaker (VCB), which is tested on the platform in conjunction with a 40.5-kV VCB prototype to showcase the success of the proposed motor actuator and its control method.

High-fat diet (HFD) induced hepatic endoplasmic reticulum (ER) stress drives insulin resistance (IR) and steatosis. NK cells in adipose tissue play an important role in the pathogenesis of IR in obesity. Whether NK cells in the liver can induce hepatic ER stress and thus promote IR in obesity is still unknown. We demonstrate that HFD-fed mice display elevated production of proinflammatory cytokine osteopontin (OPN) in hepatic NK cells, especially in CD49a+DX5– tissue-resident NK (trNK) cells. Obesity-induced ER stress, IR, and steatosis in the liver are ameliorated by ablating NK cells with neutralizing antibody in HFD-fed mice. OPN treatment enhances the expression of ER stress markers, including p-PERK, p-eIF2, ATF4, and CHOP in both murine liver tissues and HL-7702, a human liver cell line. Pretreatment of HL-7702 cells with OPN promotes hyperactivation of JNK and subsequent decrease of tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1), resulting in impaired insulin signaling, which can be reversed by inhibiting ER stress. Collectively, we demonstrate that hepatic NK cells induce obesity-induced hepatic ER stress, and IR through OPN production.