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Six novel AECs of [Sr(o-CPA)2(H2O)4]·(o-CPA) 1, [Ba(o-CPA)2(H2O)]·H2O 2, [Sr(m-CPA)2(H2O)4]·(m-CPA) 3, [Ba(m-CPA)2(H2O)4]2·2(m-CPA)·H2O 4, [Sr(p-CPA)2(H2O)] 5 and [Ba(p-CPA)2(H2O)] 6 (o-CPA = 2-chlorophenoxyacetic acid, m-CPA = 3-chlorophenoxyacetic acid and p-CPA = 4-chlorophenoxyacetic acid) were synthesized by a facile microwave-assistant reaction. The solid-state structures were well established by X-ray crystallography and routine analyses of Fourier transform infrared, elemental analysis, field emission scanning electron microscope (FESEM) and thermogravimetric analysis. The structure data reveal that complexes of 1, 3 and 4 are one-dimensional chains with a zigzag arrangement, while 2, 5 and 6 are (4, 4) rhomboid two-dimensional grid structures. It is noticed that the carboxyl group in these complexes displays multiple coordination modes of μ2-η1:η1 (1, 2, 3, 4, 5 and 6), μ3-η1:η2 (1, 2, 3 and 4), μ2-η1:η2 (2), μ3-η2:η2 (5 and 6). Interestingly, the oxygen atoms of flexible –OCH2– in phenoxy groups take part in coordination behavior with metal centers through the rotation of the C–O and C–C bonds in complexes 2, 5 and 6, while only carboxyl group coordination can be found in complexes 1, 3 and 4. FESEM images indicate that the surface appearances of complexes are totally different from ligands after coordination. All ligands and complexes were evaluated for activity as plant-growth inhibitors against Amaranth (Amaranthus spp.) and barnyard grass. Compared with ligands, complexes 1, 3 and 4 exhibited better response index (RI) values of Shoot elongation against barnyard grass. Moreover, complexes 1, 3 and 4 demonstrated a higher inhibitory activity than 2, 5 and 6. It is significant to develop a new kind of environmentally-friendly herbicide based on these kinds of complexes for their low toxicity and high efficiency.

Proceedings of the National Academy of Sciences of the United States of America 117(5), 2432 - 2440 (2020). doi:10.1073/pnas.1910208117, Phytochromes and related photoreceptors distinguish themselves for their long-wavelength absorption and large spectral shift between parental state and photoproduct. Both features are not well understood, partly due to lack of high-resolution structural data and insufficient support from quantum-chemical calculations. The red–green switching cyanobacteriochrome Slr1393g3 shows an absorption shift larger than 110 nm. Both parental state and photoproduct could be crystallized with high resolution, together with a “hybrid” form carrying the chromophore in parental state geometry, whereas the protein remained in the photoproduct conformation. The crystal structures reveal how chromophore and protein mutually regulate their conformational changes, yielding the observed spectral shift. Quantum-chemical calculations, based on these structures, provide a deeper understanding of the spectral tuning mechanisms., Published by National Acad. of Sciences, Washington, DC

Flexible manufacturing cell (FMC) was the extension of the CNC machining center,which consisted of three portions , a CNC machining center , an industrial robot and unified by a the background computer programmable control. In order to guarantee the rationality and feasibility of the automatic operation loading and unloading workpieces , the simulation object was based on the KUKA robot of flexible manufacturing cell in this paper, which based on MATLAB/GUI and combinated of VRML language and information transmission method development between MATLAB and the simulation system of flexible manufacturing unit. According to the set up parameters and angles, the model was implemented. Through the control panel and the robot's real-time interactive simulation, 3d visualization window can be real-time display of the robot simulation, and validated the path planning. According to the simulation results of the model , it could provide reference to the actual movement of the KUKA robot trajectory planning, provided the better fully automated feasibility analysis of flexible manufacturing cell, and proved the improvement of flexible manufacturing unit operation scientifically and reasonably.

TiO2nanorods were successfully fabricated via hydrothermal method using cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. The synthesized samples were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope (FESEM). The study showed that as-prepared samples were the mixed crystalline phase of rutile and brookite. The weight fraction of rutile and brookite in the mixed-phase were accurately tuned by changing the concentration of CTAB. The morphology of prepared samples was TiO2nanorods with the diameter of 2530 nm and the length of 80150 nm. The samples for degradation of papermaking wastewater under ultraviolet light irradiation showed better photocatalytic activity than the commercial Degussa P25. HRT-3 prepared from CTAB: TBT molar ratio of 0.48 exhibited the highest photocatalytic activity, achieving 47.2% CODcrremoval rate and 89.5% chroma removal rate under irradiation 12 h.

The numerical control machine tool, which is a typical energy-using product, because there are all sorts of energy loss and auxiliary functions, has low efficiency in machining process. Author makes a study of NC machine tool energy consumption controlling. With simens840Dsl numerical control system as an example, based on the analysis of CNC system control principle, according to processing characteristic of the part, the macro program is wrote to optimize dynamic characteristics of NC machine tool. According to the machine idle time in different work condition, three energy-saving control profiles are formulated, including machine standby, NC standby, auto shut off. By the formulation of the corresponding PLC control logic, low energy consumption of intelligent control of NC machine tool is realized. Integrate PAC3200/4200 multi-function meter in NC machine tools, quantitative measurement and analysis of energy consumption for numerical control system and ancillary equipment can be implemented, and machine tool real-time energy data can be obtained. This scheme has been successfully applied in long-men portable CNC machine tools, and obtained the ideal effect: to realize the optimize control of energy consumption, improve the performance of the machine tool, become more market competitiveness.

A model simplification method for linear discrete systems is presented to determine both numerator and denominator coefficients of a simplified model by differential evolution algorithm in order to minimize the root mean squared error between the step responses of original and simplified models. The performance of the proposed method was demonstrated by two examples with different orders and the results show that the method can yield a good approximation of the original system.

SARS‐CoV spike (S) protein‐mediated cell fusion is important for the viral entry mechanism and identification of SARS‐CoV entry inhibitors. In order to avoid the high risks involved in handling SARS‐CoV and to facilitate the study of viral fusion mechanism, we established the cell lines: SR‐COS7 cells that stably express both SARS‐CoV S protein and red fluorescence protein, R‐COS7 cells that stably express red fluorescence protein, and AG‐COS7 cells that stably express both ACE2 and green fluorescence protein, respectively. When SR‐COS7 cells or R‐COS7 cells were cocultured with AG‐COS7 cells, syncytia with yellow fluorescence were conveniently observed after 12 h in SR‐COS7 cells plus AG‐COS7 cells, but not in R‐COS7 cells plus AG‐COS7 cells. The cell‐to‐cell fusion efficiency was simply determined for quantitative analysis based on the number of syncytium detected by flow cytometry. Such new cell‐to‐cell fusion model was further assessed by the potent HR2 peptide inhibitor, which led to the obvious decrease of the cell‐to‐cell fusion efficiency. The successful fusion and inhibition of cell‐based binding assay shows that it can be well used for the study of SARS‐CoV entry and inhibition. iubmb Life, 58: 480 ‐ 486, 2006

Two electron donor–π-acceptor (D–π-A) chromospheres, with ferrocene as the electron donor and pyridinium as the electron acceptor, were synthesized. The nonlinear optical absorption (NOA) properties in the solution state were investigated by the Z-scan technique. Both compounds exhibited reverse saturable absorption (RSA) and optical limiting effect under nanosecond pulse irradiation.

The second GAF domain of AnPixJ, AnPixJg2, a bilin-binding protein from the cyanobacterium Anabaena PCC 7120, undergoes a photoinduced interconversion between a red-absorbing state, Pr, and a green-absorbing state, Pg. Combining ultraviolet-vis (UV-vis), infrared, resonance Raman (RR), and magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, we have studied this cyanobacteriochrome (CBCR) assembled with phycocyanobilin (PCB) either in vivo or in vitro. In both assembly routes, the spectroscopic data of the Pr state reveal nearly identical chromophore structures with a protonated (cationic) bilin. However, unlike the native (in vivo assembly) Pg photoproduct, in which the bilin retains protonation, the Pg generated from the in vitro-assembled AnPixJg2 harbors a deprotonated (neutral) bilin chromophore at pH 7.8. IR difference spectroscopy further reveals the transfer of a proton from the bilin to a side-chain carboxylate on an amino acid, probably Asp291. Besides the change in protonation state, the bilin structure is very similar in the in vitro- and in vivo-assembled Pg photoproducts. The chromophore of the in vitro Pg becomes protonated when the pH is increased to 10, presumably because of a partial reversal of protein misfolding. Most remarkably, the electronic transitions remain unchanged and are very similar to those of the native Pg. Thus, bilin protonation is not a key parameter for controlling the energies of the electronic transitions in AnPixJg2. Possible alternative molecular mechanisms for color tuning are discussed.

Based on the reported cDNA sequences of BmKalphaTxs , the genes encoding toxin BmKalphaTx11 and BmKalphaTx15 were amplified by PCR from the Chinese scorpion Buthus martensii Karsch genomic DNA employing synthetic oligonucleotides. Sequences analysis of nucleotide showed that an intron about 500 bp length interrupts signal peptide coding regions of BmKalphaTx11 and BmKalphaTx15. Using cDNA sequence of BmKalphaTx11 as probe, southern hybridization of BmK genome total DNA was performed. The result indicates that BmKalphaTx11 is multicopy genes or belongs to multiple gene family with high homology genes. The similarity of BmKalpha-toxin gene sequences and southern hybridization revealed the evolution trace of BmKalpha-toxins: BmKalpha-toxin genes evolve from a common progenitor, and the genes diversity is associated with a process of locus duplication and gene divergence.

The protein encoded by the gene slr1393 from the cyanobacterium Synechocystis sp. PCC6803 (Slr1393) is composed of three GAF domains, a PAS domain, and a histidine kinase motif. The third GAF domain (referred to as GAF3) was previously characterized as the sole domain in this protein, being able to carry phycocyanobilin (PCB) as the chromophore and to accomplish photochemistry. GAF3 shows photochromicity, and is able to switch between a red-absorbing parental state (GAF3R, ?max = 649 nm) and a green-absorbing photoproduct state (GAF3G, ?max = 536 nm) upon appropriate irradiation. In this study we have determined the photochemical quantum yields for the interconversion between both forms using two methods: an "absolute" method and a reference-based control. The latter is a comparative procedure which exploits a well-characterized blue-light photoreceptor, YtvA from Bacillus subtilis, and the cyanobacterial phytochrome Cph1 as actinometers. The former is an ad hoc developed, four laser-based setup where two cw lasers provide the pump beams to induce photoswitching (red to green and green to red, respectively) and two cw lasers simultaneously monitor the appearance and disappearance of the two species. Interestingly, fit analysis of the recorded transient absorbance changes provided a quantum yield for the green -> red conversion (?0.3) at least three times larger than for the red -> green conversion (?0.08). These data are in agreement with the results from the comparative method documenting the usefulness of the 'direct' method developed here for quantum yields' determination. The light-induced switching capability of this photochromic protein allowed measuring the kinetics of GAF3 immobilized on a glass plate, and within living, overexpressing Escherichia coli cells.

Curcumin has a wide spectrum of pharmaceutical properties such as antitumor, antioxidant, antiamyloid, and anti-inflammatory activity. However, poor aqueous solubility and low bioavailability of curcumin are major challenge in its development as a useful drug. To overcome many of these problems, curcumin-loaded long-circulating liposomes (Cur-LCL) were prepared by the ethanol injection method. Morphology of Cur-LCL was observed by transmission electron microscope, mean particle size and Zeta potential were detected by laser particle size analyzer, entrapment efficiency and drug loading were evaluated by ultracentrifugation. The drug release behavior in vitro and pharmacokinetic behavior in rats of Cur-LCL were investigated with curcumin (Cur) and curcumin liposomes (Cur-Lips) as control. The results showed that the mean diameter of Cur-LCL was 110 nm, the Zeta potential was -5.8 mV. The entrapment efficiency and drug loading of Cur-LCL was 80.25%, 2.06%, respectively. The release behavior in vitro studied by dialysis in PBS buffer showed significant sustained release profile that 48.95% Cur were released from Cur-LCL in 7 h, 88.92% in 24 h. The pharmacokinetic parameters showed that compared with Cur and Cur-Lips, the t(1/2beta) of Cur-LCL was extended to 13 and 1.8-fold, respectively. Besides, the AUC values was significantly increased (P0.01), and the clearance was evidently decreased (P0.01). These results from in vitro and in vivo indicated that Cur-LCL were able to realize controlled drug release and increase circulation time.

The gene slr1393 from Synechocystis sp. PCC6803 encodes a protein composed of three GAF domains, a PAS domain, and a histidine kinase domain. GAF3 is the sole domain able to bind phycocyanobilin (PCB) as chromophore and to accomplish photochemistry: switching between a red-absorbing parental and a green-absorbing photoproduct state (lmax=649 and 536 nm, respectively). Conversions in both directions were followed by time-resolved absorption spectroscopy with the separately expressed GAF3 domain of Slr1393. Global fit analysis of the recorded absorbance changes yielded three lifetimes (3.2 ms, 390 ms, and 1.5 ms) for the red-to-green conversion, and 1.2 ms, 340 ms, and 1 ms for the green-to-red conversion. In addition to the wild-type (WT) protein, 24 mutated proteins were studied spectroscopically. The design of these site-directed mutations was based on sequence alignments with related proteins and by employing the crystal structure of AnPixJg2 (PDB ID: 3W2Z), a Slr1393 orthologous from Anabaena sp.PCC7120. The structure of AnPixJg2 was also used as template for model building, thus confirming the strong structural similarity between the proteins, and for identifying amino acids to target for mutagenesis. Only amino acids in close proximity to the chromophore were exchanged, as these were considered likely to have an impact on the spectral and dynamic properties. Three groups of mutants were found: some showed absorption features similar to the WT protein, a second group showed modified absorbance properties, and the third group had lost the ability to bind the chromophore. The most unexpected result was obtained for the exchange at residue 532 (N532Y). In vivo assembly yielded a red-absorbing, WT-like protein. Irradiation, however, not only converted it into the greenabsorbing form, but also produced a 660 nm, further-red-shifted absorbance band. This photoproduct was fully reversible to the parental form upon green light irradiation. Fil: Xu, Xiu Ling. Max-Planck-Institute for Chemical Energy Conversion; Alemania Fil: Gutt, Alexander. Max-Planck-Institute for Chemical Energy Conversion; Alemania Fil: Mechelke, Jonas. Max-Planck-Institute for Chemical Energy Conversion; Alemania Fil: Raffelberg, Sarah. Max-Planck-Institute for Chemical Energy Conversion; Alemania Fil: Tang, Kun. Max-Planck-Institute for Chemical Energy Conversion; Alemania. Huazhong Agricultural University; República de China Fil: Miao, Dan. Huazhong Agricultural University; República de China Fil: Valle, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina Fil: Borsarelli, Claudio Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina Fil: Zhao, Kai Hong. Huazhong Agricultural University; República de China Fil: Gärtner, Wolfgang. Max-Planck-Institute for Chemical Energy Conversion; Alemania

The mesaconitine and its major metabolites in the rat urine were identified by liquid chromatography and electrospray ionization tandem mass spectrometry. The rat urine was collected for consecutive 24 hours from the rat following intragastric infusion of mesaconitine, subsequently which were enriched and purified using solid phase extraction. The metabolites of mesaconitine in the rat urine were analyzed by the liquid chromatography and electrospray ionization tandem mass spectrometry. It is shown that the parent drug mesaconitine and its metabolites were found in the rat urine, such as hypo-mesaconitine glucuronic acid conjugate, 10-hydroxy-mesaconitine, 1-O-demethyl mesaconitine, deoxy-mesaconitine and hypo-mesaconitine. Among the five of metabolites, the hypo-mesaconitine glucuronic acid conjugate (m/z 766) was first discovered as the aconitine in rats phase II metabolites, which revealed a new way of mesaconitine metabolism in rats.

Quox-1 is the only gene in the hox family whose expression occurs throughout the development of the central nervous system. Using the Quox-1 homeodomain produced in a bacterial expression system, we were able to identify DNA-binding targets of the Quox-1 protein from a library of randomly generated oligonucleotides by the selection and amplification binding (SAAB) technique. The results indicated that the Quox-1 protein recognizes a new consensus sequence, 5'-CAATC-3', which has not been reported for any other Hox family homeoprotein. In addition, electromobility shift assay further confirmed that the Quox-1 homeoprotein preferentially binds to the 5'-CAATC-3' sequence, but not to the binding sites for other Hox class homeoprotein (TAAT) or NKX class homeoprotein (CAAG). Based on mutation analyses of the DNA sequences, we found that the 5'-CAATC-3' core sequences are required for high affinity binding by the Quox-1 protein. Furthermore, mutation analyses of the Quox-1 homeodomain showed that one of the major determinants participating in recognition of a minor groove is the Gln6 and Thr7 in the N-terminal arm of the homeodomain.