Search

The cation-π interaction and the hydrophobic effect are important intermolecular forces in chemistry and play major roles in controlling recognition in biological systems. We compared their relative contributions to the binding of molecular "dumbbell" guests in synthetic container hosts in water. The guests offered direct, intramolecular competition between trimethylammonium groups, -N+(CH3)3, and tert-butyl groups, -C(CH3)3, for the internal surfaces (aromatic panels) of the containers. In contrast with previous studies, the container molecules consistently preferred binding to the uncharged tert-butyl groups, regardless of the presence of anionic, cationic, or zwitterionic groups on the container peripheries. This preference is determined by solvation of the polar trimethylammonium group in water, which outcompetes the attraction between the positive charge and the π-surfaces in the container. The synthetic container complexes provide a direct measure of the relative strengths of cation-π interactions and desolvation in water. Interactions with the uncharged tert-butyl group are more than 12 kJ mol-1 more favorable than the cation-π interactions with the trimethylammonium group in these cavitand complexes.

We report the synthesis and characterization of a new water-soluble cavitand 1. The container features 2-aminobenzimidazole panels at the "rim" and pyridiniums at the "feet". In the solid state, a single-crystal X-ray structure of the organic-soluble precursor 2 showed a stable vase form. The structure is stabilized by hydrogen-bonded bridges between adjacent panels through solvents and ions. In aqueous solution, binding of hydrophobic and amphiphilic guest molecules to 1 was investigated using 1H NMR. Alkanes, alcohols, acids, diols, and diacids formed 1:1 host-guest complexes, and the guest conformations were deduced from characteristic chemical shift changes. In the presence of [Pd(ethylenediamine)(H2O)2·2NO3], cavitand 1 formed a complex incorporating two metals. The metal-coordinated cavitand also bound hydrophobic linear alkanes and difluorobenzene isomers in aqueous medium. The metallo-cavitand showed shape and size selectivity and was used to separate o-difluorobenzene from its isomers as observed by 19F NMR spectroscopy. The primary amino function of the cavitands offers possibilities for further elaboration to covalent clusters of these container compounds.

A water-soluble cavitand bearing a benzotriazole upper rim was prepared and characterized. It exists as a dimeric velcraplex in D

The global prevalence of nonalcoholic steatohepatitis (NASH) increases incredibly. NASH ends up to advanced liver disease, which is highly threatening to human health. Currently, treatment of NASH is very limited. Acetyl-CoA carboxylases (ACC1/ACC2) are proved as effective drug targets for NASH. We aimed to develop novel ACC inhibitors and evaluate their therapeutic value for NASH prevention. ACC inhibitors were obtained through structure-based drug design, synthesized, screened from ACC enzymatic measurement platform and elucidated in cell culture-based assays and animal models. The lipidome and microbiome analysis were integrated to assess the effects of WZ66 on lipids profiles in liver and plasma as well as gut microbiota in the intestine. WZ66 was identified as a novel ACC1/2 inhibitor. It entered systemic circulation rapidly and could accumulate in liver. WZ66 alleviated NASH-related liver features including steatosis, Kupffer cells and hepatic stellate cells activation in diet-induced obese mice. The triglycerides (TGs) and other lipids including diglycerides (DGs), phosphatidylcholine (PC) and sphingomyelin (SM) were decreased in WZ66-treated mice as evidenced by lipidome analysis in livers. The lipids profiles in plasma were also altered with WZ66 treatment. Plasma TG were moderately increased, while the activation of SREBP1c was not detected. WZ66 also downregulated the abundance of Allobaculum, Mucispirillum and Prevotella genera as well as Mucispirillum schaedleri species in gut microbiota. WZ66 is an ideal lead compound and a potential drug candidate deserving further investigation in the therapeutics of NASH.

In this paper, we focus on the problem that the sound circuit keeps ringing when the countdown timer countdown to 0. To solve this problem, we have made many improvements. For the first time, we use Dingdong music chip to add Loudspeaker, after 10 seconds countdown, the loudspeaker "ding dong" stops three times; The buzzer is used for the second improvement, but the sound does not work normally, it sounds every 2 seconds, and finally it is successfully improved to make the buzzer stop automatically after ringing for a period of time as required by us. The paper gives the design schematic diagram, PCB diagram, and the actual circuit board display. Finally, the conclusion is summarized. The schematic diagram and PCB diagram improved for the first time with Ding Dong music chip and finally with buzzer can be directly applied because they have passed the experiment.

A reconfigurable loop antenna with two parasitic grounded strips for modern smartphone devices is presented in this paper. The most essential merit of this proposed reconfigurable antenna is that it can keep the intactness of the outer metal rim. In addition, it can generate multiantenna modes. The outer metal rim generates three loop modes and the inner parasite grounded strips can provide two monopole modes. By merging these two types of antenna modes, it can offer two wide bandwidths to cover GSM850/900, DCS/PCS/UMTS2100, and LTE2300/2500 operations with a compact antenna size of 945 mm2. The detailed operating principles and design considerations of this proposed reconfigurable antenna are described. In order to validate this proposed antenna, it was fabricated and tested. The measured antenna efficiencies and gains are satisfied with the requirements for the modern communication devices.

We present a finite impulse response (FIR) filter by using field programmable gate array (FPGA). It is designed in MATLAB, and we get filter coefficient from it. The implementation results showed decent performance in filtering.

The exhaust heat loss of the power plant boiler can account for more half of the boiler heat loss, exhaust gas temperature is 110~160 °Ccommonly, so the exhaust gas heat can be used to reduce the coal consumption, raise the economic benefits. Before and after the desulfurization tower of a 350 MW unit, there installs two plate heat exchangers, heating condensation water respectively, which can improve the thermal efficiency. With two heat exchangers working under the design conditions, a test was carried out based on a 350 WM unit simulation system in order to test the influence of system for unit operation characteristics. Referring to the data, the investment of the heat exchanger can achieve 2.68 g/kWh coal saving during the non-heating period and 0.2531 g/kWh during the heating period.

Considering that high levels of nitric oxide (NO) exert anti-cancer effect and the derivatives of oleanolic acid (OA) have shown potent anti-cancer activity, new O

A series of 2- and 5-(1,1-dimethyl-1, 2, 5, 6-tetrahydropyridinium-3-yl) oxadiazoline iodides, which might be used as M, muscarinic receptor agonists, was synthesized from nicotinaldehyde and nicotinhydrazine, respectively. Their structures were characterized by 1H NMR, ER, MS spectra and elemental analysis.

Molecular diversity of halophilic archaea from Ayakekumu salt lake was investigated by the polymerase chain reaction (PCR) amplification and culture methods. 19 water samples and 15 soil samples were taken from 19 sites within Ayakekumu salt lake in winter and spring. Under aerobic culture conditions, some halophilic microorganisms were isolated by five different media. The 16S rRNA gene sequences of 62 red strains were amplified by using PCR, determined by the DNA sequencer and analyzed through the BLASTn program subsequently. Results revealed that all sequences belonged to six genera grouped within the Halobacteriaceae. Mostly 16S rRNA gene sequences related to the genera Halorubrum (47%) and Natrinema (24%) were detected. Subsequent analysis by using Shannon index indicated that cultured halophilic archaeal diversities are not significantly different between winter and spring samplings in Ayakekumu salt lake. Similarity values of haloarchaeal 16S rRNA gene sequences to known sequences were less than 97%, suggesting the presence of two novel taxa. In addition, taxonomic characteristics of Natrinema altunense and Halobiforma lacisalsi isolated from Ayakekumu salt lake had been described previously. The discovery of the novel species provides new opportunity to further examine the diversity of these halophilic microorganisms in Ayakekumu salt lake.

Three strains of Gram-negative, aerobic, neutrophilic and halophilic bacteria were isolated from samples of a salt lake on the Qinghai–Tibet Plateau and a subterranean saline well in the Si-Chuan Basin of China. These isolates, designated AJ275T, AJ282Tand ZG16T, were investigated using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the isolates could be affiliated to the genusHalomonas. Genomic DNA G+C contents were 65.9 mol% for AJ275T, 56.7 mol% for AJ282Tand 57.6 mol% for ZG16T. The results of DNA–DNA hybridizations, fatty acid analysis and physiological and biochemical tests allowed the isolates to be differentiated genotypically and phenotypically from closely related species. It is proposed that strains AJ275T(=CGMCC 1.6493T=JCM 14606T=LMG 23976T), AJ282T(=CGMCC 1.6494T=JCM 14607T=LMG 23978T) and ZG16T(=CGMCC 1.6495T=JCM 14608T=LMG 23977T) represent the type strains of three novel species in the genusHalomonas:Halomonas saccharevitanssp. nov.,Halomonas arcissp. nov. andHalomonas subterraneasp. nov., respectively.

Finding effective chemotherapeutic agents for clinical use is a long-lasting goal in medicinal chemistry. In this study, we report a new class of α₁-adrenoceptor (α₁-AR) antagonists. Specifically, we describe the synthesis and the blocking activities toward α₁-AR of 7-(2-hydroxypropoxy)-3,4-dihydroisoquinolin-1(2H)-one 1 and its structurally perturbed analogs 2-11 that were designed according to the principle of bioisosterism. Their structures were identified with IR, (1) H NMR, MS, HRMS and elemental analysis. The blocking activities of compounds 1-11 were evaluated on isolated rat anococcygeus muscles. The results indicated that these compounds showed moderate to good activities. Among them, compound 1 exhibited the highest activity that was comparable to those of known α₁-AR antagonists tamsulosin and DDPH (1-(2,6-dimethylphenoxy)-2-(3,4-di- methoxyphenylethylamino)propane hydrochloride) and thus may be exploitable as a lead compound for the discovery of promising α₁-AR antagonists.

The Shijiazhuang six-line tunnel of the Beijing-Shijiazhuang passenger special line is adjacent to a busy and important railway, the Beijing-Guangzhou railway line. Reinforced concrete enclosing piles are adopted during the tunnel excavation cut, and two structures of anchor, reinforced concrete stays and anchor lateral support system are also used. In order to ensure construction and construction process safety, the vibration of the foundation pit piles immediately adjacent to the Beijing-Guangzhou line is tested. In this paper, the time-history curve and spectral curve of the pile is given due to a moving bullet train (Lei, 2003). Analysis of test data provides a useful experience and reference for similar projects in the future.

To discover a novel antitumor lead compound derived from fluoroquinolone, C3 carboxyl group of ciprofloxacin (1) was replaced with heterocyclic ring to form cyclopropyl fluoroquinolone aminothiadiazole scaffold (2), then reacted with aromatic aldehydes to give the Schiff bases compounds (3a-3j). The structures of new compounds were characterized by element analysis and spectral data, and their in vitro antitumor activity against SMMC-7721, HL60 and L1210 cell lines was evaluated by MTT assay via the respective IC50 values. The bioactive assay showed that eleven thiadiazole-substituted ciprofloxacin derivatives displayed potential cytotoxicity against the tested cancer cell lines, where the IC50 values of compounds 3d and 3f reached micromolar concentration. Therefore, the C3 carboxyl group of fluoroquinolone is not necessary to antitumor activity. Functionally modified heterocycle-substituted fluoroquinolone as potent antitumor lead compound is valuable for further study.

To optimize the synthetic method and antibacterial activity of fused heterocyclic thiadiazole compounds, cyclocondensation of 2-(4-methoxyphenyl)-5-amino-1,3,4-thiadiazole (2) with alpha-chloro-4-chloro acetophenone (3) resulted in a key intermediate (4), 6 -(4-chlorophenyl)-2-(4-methoxyphenyl)-imidazo-[2,1-b][1,3,4]thiadiazole, which was carried out an nucleophilic substitution with substituted piperazine to give the corresponding free bases of piperazine (5a-5c), then followed by Mannich reaction with heterocyclicamines and formaldehyde to yield the corresponding Mannich bases, (1a-11) as respective hydrochloride salts. The structures were confirmed by IR, 1H NMR, MS and elemental analysis and the antibacterial activities in vitro of fifteen newly synthesized compounds were also tested against Gram positive bacteria and Gram negative bacteria with the standard 2-fold agar dilution method. The antibacterial results showed that the introduction of a polar group resulted in the enhancement of antibacterial activity in vitro. Thus, the structures of these fused compounds could further be investigated.

A halophilic, Gram-negative bacterial strain, designated AJ261T, which was isolated from a soil sample from a salt lake on the Qinghai-Tibet Plateau, was subjected to a polyphasic taxonomic study. The isolate grew optimally in the presence of 3-5 % NaCl and used various carbohydrates as sole carbon and energy sources. The genomic DNA G+C content was 63.0 mol%. The predominant fatty acids were C18 : 1omega7c, C16 : 0 and C12 : 0. A phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate had the highest sequence similarity with respect to type strains of Halomonas elongata (98.2 %), Halomonas eurihalina (98.1 %) and Halomonas halmophila (97.2 %). The DNA-DNA relatedness of strain AJ261T with respect to H. elongata NBRC 15536T, H. eurihalina CGMCC 1.2318T and H. halmophila DSM 5349T was 42, 25 and 26 %, respectively. Overall, the phenotypic, genotypic and phylogenetic results demonstrate that strain AJ261T represents a novel species within the genus Halomonas, for which the name Halomonas caseinilytica is proposed. The type strain is AJ261T (=CGMCC 1.6773T =JCM 14802T).

A Gram-negative, aerobic, neutrophilic and extremely halophilic archaeon (strain AJ201T), isolated from Ayakekum salt lake on the Qinghai–Tibet Plateau, was investigated by a polyphasic approach. The DNA G+C content of strain AJ201Twas 65.7 mol%. The major polar lipid profile and phylogenetic analysis based on 16S rRNA gene sequences supported the allocation of the strain to the genusHalorubrum. The results of DNA–DNA hybridizations and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain AJ201Tfrom closely related species. Therefore, strain AJ201Trepresents a novel species of the genusHalorubrum, for which the nameHalorubrum arcissp. nov. is proposed. The type strain is strain AJ201T(=CGMCC 1.5343T=JCM 13916T).

Some novel members of extremely halophilic Archaea, strain AJ11, AJ12 and AJ13, were isolated from Aularz Lake located in Altun Mountain National Nature Reserve of Xinjiang Uygur Autonomous Region in China. Partial DNA fragments encoding a bacteriorhodopsin (BR) as well as for 16S rRNA of isolated strains were amplified by PCR and their DNA sequences were determined subsequently. On the basis of homology and phylogenetic analysis about 16S rDNA, it was considered that the isolated strains formed a microbiological population are the members of genus Natrinema. The results of genetic analysis, such as GC content, transition/transversion (Ti/Tv) rate ratios, synonymous substitution rates (Ks), indicated that the br fragments with high level of genetic divergence are faced with both purifying selection and bias mutation pressure. The study provides the base for using of species and BR proteins resources.

To study the synthetic method and antibacterial activity of amino-heterocyclic compounds coupled oxime-ether group.The treatment of 4-amino-3-methyl-5-mercapto-s-triazole (3) with beta-chlorophenyl-propanone to form amino-s-triazole sulfanylphenyl-propanone (4) sequentially followed by oximation with hydroxyl-amine to produce the oximes (5) and etherification with various oxadiazole chloromethanes (6a - j) to yield the title compounds (1a - j). The in vitro antibacterial activities of all newly synthesized compounds were tested against Gram positive bacteria and Gram negative bacteria with the standard 2-fold agar dilution method.Twelve new compounds including two intermediates were synthesized and their structures were confirmed by IR, 1H NMR, MS and elemental analyses. The ten title compounds exhibited the potential antibacterial activities in vitro.Theses compounds should be optimized.

To search for potential anti-atherosclerosis drugs with vascular relaxation activity, a series of agonists of endothelial targets were designed and synthesized.Coupling N-methyl-1,2, 3,6-tetrahydrapyridine ring system with 3,4-dibenzenesulfonyl-1,2,5-oxadiazole-2-oxide through esterification or amidation, a series of arecoline derivatives containing NO donors were designed and synthesised.A novel series of compounds structurally related to arecoline have been prepared, the proposed structures of eighteen new compounds were established by IR, 1H NMR, MS spectroscopy and elemental analysis. The effects of the target compounds on the vasodilation activity were tested in the isolated preparation of mice thoratic aorta.This preliminary pharmacological tests showed that the candidates have good vasodilation activities and were worthy to be intensively studied.

To study on synthesis and antibacterial activity evaluation of polyheterocycles.The condensation of 4-amino-3-pyridin-3-yl-4H-[1,2,4] triazole-5-thiol with 2-chloromethyl-5-substituted phenyl-[1,3,4] oxadiazoles gave the corresponding title heterocycle amines, and the in vitro antibacterial activity was primarily evaluated by the method of cup-plate diffusion solution.Twelve novel compounds were synthesized, and their structures were confirmed by IR, 1H NMR, MS and element analysis. Biological screening results demonstrated that most of the compounds prepared showed good antibacterial activity.Oxadiazoles incorporting pyridyl triazole ring may be a pharmacophor structure in the molecule for developing antibacterial candidate drugs.

Studies on synthesis and antibacterial activity of new heterocycles.The cyclocondensation of [(3-pyridyl)-1,3,4-oxadiazol-2-yl] thio acetic acid with various aroyl hydrazines in the presence of POCl3 and xylene gave the corresponding titled compounds, and the in vitro antibacterial activity was primarily evaluated by the method of cupplate diffusion solution.Sixteen novel titled compounds were synthesized, their structures were confirmed by IR, 1HNMR, MS and elemental analysis. Biological screening results demonstrated that most of the compounds prepared displayed potential antibacterial activity.Oxadiazoles incorporting pyridyl oxadiazole ring may be usefully antibacterial candidate drugs.

In search of more potent, less toxic and selective potassium channel openers.According to the structure-activity relationships of benzopyran compounds and the features of structures of aprikalim, dofetilide and nifekalant, twenty benzopyran-4-one hydrazone derivatives have been designed and synthesized from 4-cyanophenos through acetylation, Fries rearrangment, cyclization, hydrazone, substitution reaction and so on. The compounds were tested for their vasorelaxant activity in low (30 mmol.L-1) and high (80 mmol.L-1) KCl-induced contraction of rat aorta to identify potential potassium channel openers in vitro.Three series of twenty benzopyran-4-one hydrazone derivatives, nominated N-aminoacetyl-(6-cyano-3,4-dihydrospiro [2H-1-benzopyran-2,1'-cyclohexane]-4)-one hydrazone (I), 2-(6-cyano-3, 4-dihydro-2H-1-benzopyran-4-ylene) hydrazinethiocarboxamide derivatives (II) and N-(2-arylethyl) aminoacetyl-(6-cyano-3,4-dihydro-2H-1-benzopyran)-4-one hydrazone (III), have been synthesized. They (I1-9, II1-4 and III1-7) are new compounds. Their chemical structures were determined by IR, 1HNMR, MS and elemental analysis. The vasorelaxant effects of those novel compounds indicated that some of the compounds have vasorelaxant activities at 1 x 10(-6) mol.L-1.The vasorelaxant activities of compounds I9, III2 and III5 in inhibiting low KCl-induced vasocontraction at 1 x 10(-6) mol.L-1 are less potent than the reference compound emakalim. However they are more potent than emakalim to inhibition high concentration KCl-induced vasocontraction at 1 x 10(-5) mol.L-1. It is worthy of further study.

The title compound, C(21)H(28)N(2)O(5), has two intra-molecular N-H⋯O hydrogen bonds. Inter-molecular N-H⋯O hydrogen bonds [graph-set motif R(2) (2)(8)] give rise to a dimer. Weak N-H⋯N hydrogen bonds between neighboring dimers further extend the crystal structure, which exhibits an infinite chain motif.