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1.
Org Biomol Chem ; 19(46): 10139-10155, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34768279

RESUMEN

The simple one-step reaction of [60]fullerene with α-monosubstituted acetaldehydes and primary amines in the presence of Mn(OAc)3·2H2O under air conditions afforded a series of novel N-substituted fulleropyrrolines with trisubstituted CC bonds in moderate to good yields. The addition of Mn(OAc)3·2H2O played a crucial role in the successful synthesis of N-aryl fulleropyrrolines with trisubstituted CC bonds, which would be extremely difficult to prepare by known methods as a result of the decreased nucleophilicity of arylamines due to the p-π conjugation effect. Intriguingly, arylamines displayed abnormally higher reactivity as compared with non-arylamines in the current reaction system by the observation of obviously decreased equivalent of Mn(OAc)3·2H2O, higher product yields, and lower reaction temperature probably due to the radical reaction mechanism initiated by Mn(OAc)3·2H2O. On the basis of experimental observations, a plausible formation pathway for N-substituted fulleropyrrolines with trisubstituted CC bonds was proposed to elucidate the above-mentioned reaction process.

2.
Int J Syst Evol Microbiol ; 68(5): 1702-1706, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29580372

RESUMEN

A novel Gram-stain-negative bacterium, designated strain CY02T, was isolated from sediment of the Yellow Sea. Cells of CY02T were aerobic, coccus or short rods. Growth occurred at 5-42 °C (optimum, 35 °C), pH 6-10 (optimum, 8.0) and 0.5-9.0 % NaCl (optimum, 1.5-3.0 %). Phylogenetic analysis of 16S rRNA gene sequences revealed that CY02T was a member of the family Rhodobacteraceae and exhibited less than 95 % sequence similarities with the closely related type strains of the family Rhodobacteraceae. The genomic DNA G+C content of CY02T was 57.5 mol%. The major respiratory quinone was ubiquinone-10 (Q-10). The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, three unidentified lipids, one unidentified phospholipid and one unidentified aminolipid. The predominant cellular fatty acids were C18 : 1ω7c (57.6 %), 11-methyl C18 : 1ω7c (22.8 %) and C16 : 0 (10.6 %). Based on the results of morphological, physiological, biochemical, chemotaxonomic, genotypic and phylogenetic analyses, strain CY02T represents a novel species of a novel genus of the family Rhodobacteraceae, for which the name Neptunicoccus sediminis gen. nov., sp. nov. is proposed. The type strain of Neptunicoccus sediminis is CY02T (=CCTCC AB 2015430T=KCTC 42985T=NBRC 111872T=MCCC 1K03518).


Asunto(s)
Sedimentos Geológicos/microbiología , Filogenia , Rhodobacteraceae/clasificación , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Fosfolípidos/química , ARN Ribosómico 16S/genética , Rhodobacteraceae/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADN , Ubiquinona/química
3.
J Theor Biol ; 296: 13-20, 2012 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-22100501

RESUMEN

In this paper, we perform a complete analysis of the kinetic behavior of the general modifier mechanism of Botts and Morales in both equilibrium steady states and non-equilibrium steady states (NESS). Enlightened by the non-equilibrium theory of Markov chains, we introduce the net flux into discussion and acquire an expression of the rate of product formation in NESS, which has clear biophysical significance. Up till now, it is a general belief that being an activator or an inhibitor is an intrinsic property of the modifier. However, we reveal that this traditional point of view is based on the equilibrium assumption. A modifier may no longer be an overall activator or inhibitor when the reaction system is not in equilibrium. Based on the regulation of enzyme activity by the modifier concentration, we classify the kinetic behavior of the modifier into three categories, which are named hyperbolic behavior, bell-shaped behavior, and switching behavior, respectively. We show that the switching phenomenon, in which a modifier may convert between an activator and an inhibitor when the modifier concentration varies, occurs only in NESS. Effects of drugs on the Pgp ATPase activity, where drugs may convert from activators to inhibitors with the increase of the drug concentration, are taken as a typical example to demonstrate the occurrence of the switching phenomenon.


Asunto(s)
Catálisis , Activación Enzimática , Inhibidores Enzimáticos/química , Modelos Químicos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Adenosina Trifosfatasas/química , Enzimas/química
4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(12): 3319-23, 2012 Dec.
Artículo en Zh | MEDLINE | ID: mdl-23427560

RESUMEN

The leaf area index (LAI) is a very important parameter affecting land-atmosphere exchanges in land-surface processes; LAI is one of the basic feature parameters of canopy structure, and one of the most important biophysical parameters for modeling ecosystem processes such as carbon and water fluxes. Remote sensing provides the only feasible option for mapping LAI continuously over landscapes, but existing methodologies have significant limitations. To detect LAI accurately and quickly is one of tasks in the ecological and agricultural crop yield estimation study, etc. Emerging hyperspectral remote sensing sensor and techniques can complement existing ground-based measurement of LAI. Spatially explicit measurements of LAI extracted from hyperspectral remotely sensed data are component necessary for simulation of ecological variables and processes. This paper firstly summarized LAI retrieval method based on different level hyperspectral remote sensing platform (i. e., airborne, satelliteborne and ground-based); and secondly different kinds of retrieval model were summed up both at home and abroad in recent years by using hyperspectral remote sensing data; and finally the direction of future development of LAI remote sensing inversion was analyzed.


Asunto(s)
Ecosistema , Modelos Teóricos , Hojas de la Planta/química , Tecnología de Sensores Remotos/métodos , Análisis Espectral/métodos , Algoritmos
5.
Science ; 376(6590): 288-292, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35420967

RESUMEN

Bulk chemicals such as ethylene glycol (EG) can be industrially synthesized from either ethylene or syngas, but the latter undergoes a bottleneck reaction and requires high hydrogen pressures. We show that fullerene (exemplified by C60) can act as an electron buffer for a copper-silica catalyst (Cu/SiO2). Hydrogenation of dimethyl oxalate over a C60-Cu/SiO2 catalyst at ambient pressure and temperatures of 180° to 190°C had an EG yield of up to 98 ± 1%. In a kilogram-scale reaction, no deactivation of the catalyst was seen after 1000 hours. This mild route for the final step toward EG can be combined with the already-industrialized ambient reaction from syngas to the intermediate of dimethyl oxalate.

6.
Inorg Chem ; 50(21): 11162-72, 2011 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-21999524

RESUMEN

The [3 + 2] cycloaddition reaction of C(60) with ethyl isonicotinoylacetate in the presence of piperidine in PhCl at room temperature or in the presence of Mn(OAc)(3) in refluxing PhCl gave the pyridyl-containing dihydrofuran-fused C(60) derivative (4-C(5)H(4)N)C(O)═C(C(60))CO(2)Et (1), whereas the phenyl-containing C(60) derivative PhC(O)═C(C(60))CO(2)Et (2) was similarly prepared by [3 + 2] cycloaddition reaction of C(60) with ethyl benzoylacetate in the presence of piperidine or Mn(OAc)(3). More interestingly, one of the new porphyrin-fullerene dyads, i.e., [4-C(5)H(4)NC(O)═C(C(60))CO(2)Et]·ZnTPPH (3, ZnTPPH = tetraphenylporphyrinozinc), could be prepared by coordination reaction of the pyridyl-containing C(60) derivative 1 with equimolar ZnTPPH in CS(2)/hexane at room temperature. In addition, the ß-keto ester-substituted porphyrin derivative H(2)TPPC(O)CH(2)CO(2)Et (4) was prepared by a sequential reaction of HO(2)CCH(2)CO(2)Et with n-BuLi in 1:2 molar ratio followed by treatment with H(2)TPPC(O)Cl in the presence of Et(3)N and then hydrolysis with diluted HCl, whereas the porphyrinozinc derivative ZnTPPC(O)CH(2)CO(2)Et (5) could be prepared by coordination reaction of 4 with Zn(OAc)(2) in refluxing CHCl(3)/MeOH. Particularly interesting is that the second new porphyrin-fullerene dyad H(2)TPPC(O)═C(C(60))CO(2)Et (6) could be prepared by [3 + 2] cycloaddition reaction of 4 with C(60) in the presence of piperidine in PhCl at room temperature. In addition, treatment of 6 with Zn(OAc)(2) in refluxing CHCl(3)/MeOH afforded the third new dyad ZnTPPC(O)═C(C(60))CO(2)Et (7). All the new compounds 1-7 were characterized by elemental analysis and various spectroscopic methods and particularly for 2, 3, and 5 by X-ray crystallography. The five-component system consisting of an electron donor EDTA, dyad 3, an electron mediator methylviologen (MV(2+)), the catalyst colloidal Pt, and a proton source HOAc was proved to be effective for photoinduced H(2) evolution. A possible pathway for such a type of H(2) evolution was proposed.

7.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 2): o370, 2011 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-21523048

RESUMEN

In the title compound, C(31)H(27)NP(2), the diphenyl-phosphanyl groups are staggered relative to the PNP backbone. The N atom is displaced by 0.219 (2) Šfrom the plane formed by the two P atoms and the methylene C atom. The angles around the N atom are 120.84 (16), 113.29 (16) and 120.57 (12)°, indicating that it exhibits a distorted trigonal-pyramidal geometry. There are no classical inter-molecular inter-actions.

8.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): m1552, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22219793

RESUMEN

The dinuclear title compound, [Fe(2)(C(2)H(4)S(2))(C(24)H(20)OP(2))(CO)(5)] or (µ-SCH(2)CH(2)S-µ)Fe(2)(CO)(5)[Ph(2)PP(O)Ph(2)], con-tains a butterfly-shaped Fe(2)S(2) core in which the Fe⋯Fe separation is 2.5275 (6) Å. One of the Fe atoms is also coordinated to three carbonyl ligands and the other to two carbonyl ligands and one phosphane ligand [Ph(2)PP(O)Ph(2)]. Both Fe-atom geometries could be described as grossly distorted octa-hedral and the Ph(2)PP(O)Ph(2) ligand lies trans to the Fe⋯Fe link.

9.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): o1641, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21837046

RESUMEN

The title compound, C(8)H(9)N(3)S, is almost planar (r.m.s. deviation = 0.019 Å) apart from the terminal -NH(2) grouping [deviation of the N atom = 0.286 (2) Å]. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds, generating (001) sheets.

10.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 1): o202, 2010 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-21522704

RESUMEN

The title compound C(7)H(5)N(3)S(2), occurs as the thione tautomer in the solid state; the dihedral angle between the pyridine and thia-diazole ring planes is 2.08 (6)°. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds, generating C(8) chains propagating in [010].

11.
J Inorg Biochem ; 210: 111126, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32521290

RESUMEN

To further develop the biomimetic chemistry of [FeFe]- and [NiFe]-hydrogenases for catalytic proton reduction to hydrogen (H2), two serials of dinuclear diiron and trinuclear NiFe2 dithiolate complexes with chelating PCNCP ligands, namely, Fe2(µ-edt)(CO)4{κ2-(Ph2PCH2)2NR} (1a-1c) and Fe2(CO)6(µ3-S)2Ni{(Ph2PCH2)2NR} (2a-2c) where edt = SCH2CH2S and PCNCP = (Ph2PCH2)2NR [R = Bui (CH2CHMe2), But (CMe3), and Bun (CH2CH2CH2Me)], have been synthesized in moderate yields. All the new complexes 1a-1c and 2a-2c have been fully characterized by elemental analysis, FT-IR, NMR spectroscopy, and single-crystal X-ray diffraction analysis. More importantly, to explore the influence of transition metal cores (i.e., nickel and iron) on the electrochemical and electrocatalytic properties of hydrogenase-inspired molecular catalysts for H2 evolution, the cyclic voltammetries (CVs) of 1a-1c and 2a-2c are studied and compared in nBu4NPF6/DMF solution without and with acetic acid (HOAc) as a proton source. This finding suggests that (i) complexes 1a-1c and 2a-2c are all found to be active for electrocatalytic H2 evolution, but (ii) they display the distinct redox behaviors and electrocatalytic proton reduction abilities.


Asunto(s)
Complejos de Coordinación/química , Hidrógeno/química , Fosfinas/química , Catálisis , Complejos de Coordinación/síntesis química , Electroquímica , Hidrogenasas/química , Hierro/química , Proteínas Hierro-Azufre/química , Ligandos , Níquel/química , Oxidación-Reducción , Fosfinas/síntesis química
12.
Zhen Ci Yan Jiu ; 44(5): 319-23, 2019 May 25.
Artículo en Zh | MEDLINE | ID: mdl-31155862

RESUMEN

OBJECTIVE: To observe the effect of acupuncture at "Shenshu"(BL23)-"Taixi"(KI3)on the levels of serum uric acid (SUA) and expression of renal urate-anion transporter 1 (URAT1) and organic anion transporter 1 (OAT1) proteins in hyperuricemia (HUA) rats, so as to explore its underlying mechanisms in improving HUA. METHODS: A total of 25 male Wistar rats were divided into 4 groups: control (n=6), HUA model (n=7), BL23-KI3 (n=6) and Ganshu (BL18)-Taichong (LR3, BL18-LR3 in short, n=6). The HUA model was established by gavage of Oteracil Potassium (2 g/kg), once daily for 10 days, then once every other day. For rats of the BL23-KI3 group, BL23 and KI3 were stimulated with filiform needles which were rotated for 10 s at a frequency about 100 r/min, and for rats of the BL18-LR3 group, BL18 and LR3 were stimulated with the same methods to those of the BL23-KI3 group. The treatment of both acupuncture groups was conducted once daily, 6 times a week (except Sundays) for 3 weeks. The contents of SUA and serum creatinine (SCr) were assayed by using an automatic biochemical analyzer. The pathological changes of the right kidney tissue were observed under light microscope after hematoxylin eosin (H.E.) staining, the immunoactivity of URAT1 and OAT1 of the right kidney tissue was determined by immunohistochemistry, and the expression of URAT1 and OAT1 proteins of the left kidney tissue detected by Western blot (WB). RESULTS: After modeling, the content of SUA and the expression of renal URAT1 protein (shown by both immunoactivity and WB) were significantly increased (P<0.01), but that of renal OAT1 protein was obviously decreased in the model group compared with the control group (P<0.01). There was no notably change in the level of SCr in the model group relevant to the control group (P>0.05). Following acupuncture intervention, the SUA content and URAT1 expression in both BL18-LR3 and BL23-KI3 groups were considerably down-regulated (P<0.05, P<0.01), and the expression of OAT1 protein in the BL23-KI3 group (not the BL18-LR3 group) were obviously up-regulated relevant to the model group (P<0.01). The effects of BL23-KI3 were significant superior to those of BL18-LR3 in down-regulating the expression of URAT1 and up-regulating OAT1 protein (P<0.01, P<0.05). CONCLUSION: Acupuncture of "BL23" and "KI3" can effectively down-regulate SUA level in HUA rats, which may be related to its effects in down-regulating the expression of URAT1 and up-regulating the expression of OAT1 in the kidney tissue.


Asunto(s)
Terapia por Acupuntura , Hiperuricemia , Animales , Aniones , Masculino , Proteína 1 de Transporte de Anión Orgánico , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Ácido Úrico
13.
Space Med Med Eng (Beijing) ; 17(2): 85-8, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15909380

RESUMEN

OBJECTIVE: To compare heart rate variability (HRV) and heart rate (HR) between individuals with different emotional stabilities in two situations and to discuss the relationship between situation, emotional stability and HRV. METHOD: Ninety-six healthy male flying students were assessed after 60 h flying exercises by senior pilots using Criterion Assessment Scale of Emotional Stability of Flying Cadets (CASESFC) compiled by our department. They were divided into groups of high emotional stability and low stability. ECG were recorded in situations of Sternberg Dual Task and Flying and HRV components and HR were analyzed and compared. RESULT: When subjects were exposed to Sternberg dual task situation, individuals with high emotional stability had lower LFnorm (P<0.05), HFnorm (P<0.05), LF/HF ratio and HR (P<0.05) than those with low emotional stability. When it comes to flying situation, individuals with high emotional stability had higher LFnorm and HFnorm, but LF/HF ratio and HR (P<0.05) were still lower than those with low emotional stability. CONCLUSION: We found that there is a tendency which implies the situational separation of fluctuation of autonomic nervous system related to emotional stability. It suggests that the ability of an individual to adjust to outer environment depends not only on personality, temperament and cognitive module, but also on a physiological basis.


Asunto(s)
Sistema Nervioso Autónomo/fisiología , Emociones/fisiología , Frecuencia Cardíaca/fisiología , Adolescente , Adulto , Medicina Aeroespacial , Electrocardiografía , Humanos , Masculino , Pruebas de Personalidad
14.
Space Med Med Eng (Beijing) ; 17(2): 103-6, 2004 Apr.
Artículo en Zh | MEDLINE | ID: mdl-15909384

RESUMEN

OBJECTIVE: To established models of confirmatory factor analysis of the emotional stability criteria of flying students, and to provide an available criteria tool for evaluating the emotional stability. METHOD: "Criterion Assessment Scale of Emotional Stability of Flying Cadets" (ACSEFC) including 9 items were compiled first by interviewing with skillful pilots or flying instructors, and then the emotional stability of 153 flying students was evaluated by these pilots or instructors. RESULT: There were high level (P<0.05) of correlation coefficients between 8 items except for item 1; three-factor design appears to be the best choice for the nine items by exploratory factor analysis; model 4 appears to have the best effect by confirmatory factor analysis. CONCLUSION: The evaluation of emotional stability of flying students can be divided into 3 parts: general manifest emotion, tense before flying and flying emotion stability.


Asunto(s)
Medicina Aeroespacial , Aviación , Emociones , Modelos Psicológicos , Inventario de Personalidad/normas , Análisis Factorial , Humanos , Personalidad , Psicometría , Reproducibilidad de los Resultados , Estudiantes/psicología , Encuestas y Cuestionarios
15.
Dalton Trans ; 40(4): 837-46, 2011 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-21152555

RESUMEN

A series of new diiron azadithiolate (ADT) complexes (1-8), which could be regarded as the active site models of [FeFe]hydrogenases, have been synthesized starting from parent complex [(µ-SCH(2))(2)NCH(2)CH(2)OH]Fe(2)(CO)(6) (A). Treatment of A with ethyl malonyl chloride or malonyl dichloride in the presence of pyridine afforded the malonyl-containing complexes [(µ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(6) (1) and [Fe(2)(CO)(6)(µ-SCH(2))(2)NCH(2)CH(2)O(2)C](2)CH(2) (2). Further treatment of 1 and 2 with PPh(3) under different conditions produced the PPh(3)-substituted complexes [(µ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(5)(PPh(3)) (3), [(µ-SCH(2))(2)NCH(2)CH(2)O(2)CCH(2)CO(2)Et]Fe(2)(CO)(4)(PPh(3))(2) (4), and [Fe(2)(CO)(5)(PPh(3))(µ-SCH(2))(2)NCH(2)CH(2)O(2)C](2)CH(2) (5). More interestingly, complexes 1-3 could react with C(60) in the presence of CBr(4) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) via Bingel-Hirsch reaction to give the C(60)-containing complexes [(µ-SCH(2))(2)NCH(2)CH(2)O(2)CC(C(60))CO(2)Et]Fe(2)(CO)(6) (6), [Fe(2)(CO)(6)(µ-SCH(2))(2)NCH(2)CH(2)O(2)C](2)C(C(60)) (7), and [(µ-SCH(2))(2)NCH(2)CH(2)O(2)CC(C(60))CO(2)Et]Fe(2)(CO)(5)(PPh(3)) (8). The new ADT-type models 1-8 were characterized by elemental analysis and spectroscopy, whereas 2-4 were further studied by X-ray crystallography and 6-8 investigated in detail by DFT methods.


Asunto(s)
Compuestos Aza/química , Complejos de Coordinación/síntesis química , Hidrogenasas/química , Proteínas Hierro-Azufre/química , Hierro/química , Dominio Catalítico , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Cristalografía por Rayos X , Fulerenos/química , Hidrogenasas/metabolismo , Proteínas Hierro-Azufre/metabolismo , Modelos Moleculares , Conformación Molecular
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