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1.
魏江春  郭威 《菌物学报》2019,38(10):1600-1609
基于共祖共衍系统学分析表明,撕裂石耳Umbilicaria laceratula已被新组合为撕裂疱脐衣Lasallia laceratula,露西疱脐衣Lasallia rossica被处理为其异模异名。哈萨克石耳U. caucasica被处理为宾州疱脐衣L. pensylvanica的异模异名,而多盘石耳奥林变种Gyrophora proboscidea var. orizabae被处理为比格石耳Umbilicaria bigleri的异名。  相似文献   

2.
Abstract

The antioxidant effects of ellagic acid (EA) and hesperidin (HES) against skeletal muscle ischemia/reperfusion injury (I/R) were performed. Hindlimb ischemia has been induced by tourniquet occlusion for 2?h on left hindlimb. At the end of ischemia, the tourniquate has been removed and initiated reperfusion for 2?h. EA (100?mg/kg) has been applied orally before ischemia/reperfusion in the EA?+?I/R group. HES (100?mg/kg) has been given orally in the HES?+?I/R group. The left gastrocnemius muscle has been harvested and stored immediately at??80?°C until assessed for the levels of MDA and antioxidant enzymes activities. MDA level has statistically increased in I/R group (p?<?0.05) compared to other groups. The muscle tissue antioxidant enzymes activities were lower than the other groups in the I/R group (p?<?0.05). EA and HES treatments significantly reversed the damage level in I/R, also activity of tissue SOD increased in the EA?+?I/R and HES?+?I/R groups.  相似文献   

3.
The effect of enhanced green fluorescent protein (EGFP) on the in vitro viability of early embryos of C57BL/6--Tgn(ACTbEGFP010sb/J mice has been studied. The number of viable ova in hemizygous females (-/egfp) has been shown to decrease. Irrespective of the EGFP level, it has no deleterious effect on the early development of embryos obtained by reciprocal crossing of hemizygous (-/egfp) and wild-type (-/-) mice.  相似文献   

4.
An immunoassay that quantifies urinary S-phenylmercapturic acid (PMA), a benzene-specific biomarker, has been developed and its potential usefulness as a screening tool for monitoring occupational exposure to benzene has been demonstrated. Analytical reliability has been confirmed by correlation of results with gas chromatography-mass spectrometry (GC/MS) data (R = 0.92). The assay has been configured as a competitive enzyme-linked immunosorbent assay (ELISA) to facilitate rapid throughput of samples. The ELISA has a working range of 40-1200 nmol l-1 urinary PMA and appears to be unaffected by the presence of structurally related urinary metabolites. Background levels of 0-1.9µmol PMA/mol creatinine (mean 0.9 µmol mol-1, n = 32) were measured in non-smoking control subjects. Recent exposures to benzene (8 h time-weighted averages-TWA), during diverse industrial processes, over the range 0-4.8ppm were identified by application of the assay in biological monitoring programmes.  相似文献   

5.
R. M. Daniel 《BBA》1970,216(2):328-341
1. The nature and distribution of the electron transport system of Acetobacter suboxydans (ATCC 621) has been investigated, with particular reference to cytochrome o.

2. A highly active membrane-bound electron transport system has been demonstrated, and functional roles suggested for ubiquinone, two c-type cytochromes ( peaks at 549 and 553 nm at — 196°), and two b-type cytochromes ( peaks at 558 and 564 nm at — 196°).

3. Evidence is presented suggesting that both the b-type cytochromes may be terminal oxidases of the cytochrome o type, and that cytochrome o (558) has an O2 affinity approx. 10 times greater than cytochrome o (565), and a CO affinity only half as great.  相似文献   


6.
A method for determination of carboxymethyl cellulose (CMC) molecular weight (MW) and chemical heterogeneity (degree of oxidation (DO)) using a bi-detector HPSEC (UV-detector online with refractometer) has been developed. It has been found that the use of 0.5 N NaOH or 0.4 M acetate buffer as the eluent ensures CMC separation according to MW. It has been revealed that the universal calibration for the polyelectrolyte CMC and the neutral polymer dextran is valid under the conditions applied. The Mark–Houwink equations for CMC in 0.5 N NaOH and 0.4 M acetate buffer have been estimated to be [η]=5.37×10−4 MW0.73 and [η] =2.24×10−4 MW0.83 dl g−1, respectively. The equation log K=1.64−4.00 ml g−1 for CMC has been estimated. An approach for determining DO from adsorption at 290 or 313 nm has been developed.  相似文献   

7.
A novel five-coordinate rhenium(III)-thiolato complex, Re(SCH2C6H4OCH3-p)3(PPh3)2 has been isolated during the reaction of trans-ReOCl3(PPh3)2 with p-methoxybenzyl mercaptan. In the unexpected structure that was acquired, the central metal has undergone a reduction from Re(V) to Re(III). The five-coordinate Re(III) complex has been characterized by spectroscopic methods, elemental analysis and X-ray crystallography. X-ray crystallographic studies showed the coordination geometry around rhenium to be that of a trigonal bipyramid. The basal plane is defined by three sulfur atoms of the monodentate ligand, while the two apical positions are occupied by two phosphines of the precursor.  相似文献   

8.
长白松的木材解剖及其分类问题   总被引:1,自引:1,他引:0  
关于长白松的分类问题一直有争议[6-11],根据作者对吉林省安图县二道白河产的长白松的木材解剖研究,发现其木材的射线管胞内壁具深锯齿,颇与欧洲赤松(Pinus sylvestris Linn.)相近[14] [15],但以其木射线薄壁组织细胞水平壁无纹孔和晚材最后数列管胞弦壁上存在着排列成轴向单行小形具缘纹孔来看,这又显属赤松(Pinus densiflora Sieb.et Zucc.)的特征。因此,作者认为长白松的木材结构是处于欧洲赤松与赤松之间而更偏于赤松[10],故确认其当归属于赤松的种群范围。  相似文献   

9.
dsDNA of the influenza virus subtype A/Leningrad/385/80/R (H3N2)-recombinant A/Leningrad/385/80 (H3N2) and RR/8/34 (H1N1) has been synthesized using polyadenylated viral RNA as a template. This dsDNA has been cloned on plasmid pUC19. A clone has been selected harbouring the plasmid with included proximal fragment of hemagglutinin gene that contains the main antigenic determinants. The hybrid plasmid is hybridizable with RNA of the hemagglutinin gene and with oligonucleotide CATGCAAAACCTTCCC that is complementing the sequence coding for the proximal fragment of the mature hemagglutinin.  相似文献   

10.
Nitric oxide (NO), produced in different cell types through the conversion of L-arginine into L-citrulline by the enzyme NO synthase, has been proposed to exert its action in several physiological and pathological events. The great propensity for nitrosothiol formation and breakdown represents a mechanism which modulates the action of macromolecules containing NO-reactive Cys residues at their active centre and/or allosteric sites. Based on the human haemoglobin (Hb) structure and accounting for the known acid-base catalysed Cys beta93-nitrosylation and Cys beta393NO-denitrosylation processes, the putative amino acid sequence (Lys/Arg/His/Asp/Glu)Cys(Asp/Glu) (sites -1, 0, and + 1, respectively) has been proposed as the minimum consensus motif for Cys-NO reactivity. Although not found in human Hb, the presence of a polar amino acid residue (Gly/Ser/Thr/Cys/Tyr/Asn/Gln) at the -2 position has been observed in some NO-reactive protein sequences (e.g., NMDA receptors). However, the most important component of the tri- or tetra-peptide consensus motif has been recognised as the Cys(Asp/Glu) pair [Stamler et al., Neuron (1997) 18, 691-696]. Here, we analyse the three-dimensional structure of several proteins containing NO-reactive Cys residues, and show that their nitrosylation and denitrosylation processes may depend on the Cys-Sy atomic structural microenvironment rather than on the tri- or tetra-peptide sequence consensus motif.  相似文献   

11.
Recent advancements in mass spectrometry, especially the development of electrospray tandem mass spectrometry (ESI/LC/MS2) and matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI/TOF), have greatly facilitated analysis of complex biomolecules. It has now become possible to profile, in relatively short periods of time, large multicomponent groups of compounds biosynthesized by biological systems. The efficiency and accuracy of analysis have led to the development of new concepts of mass spectrometric profiling, mapping, and imaging. Profiling of proteins in biological material (proteomics) has become a widely accepted strategy for identification of mechanisms involved in the biochemistry of disease processes, and has become a novel tool for unraveling new drug targets. Evolution of proteomics has relied on ESI/LC/MS2 and MALDI/TOF, techniques that are also useful in the novel area of quantitative proteomics.  相似文献   

12.
糖尿病是一种常见病、多发病,严重威胁着人类的健康。现已明确,糖尿病是冠心病发病的一个重要因素。心肌缺血/再灌注(ischemia/reperfusion,I/R)损伤是临床常见的病理过程,同时是冠心病发病及心肌血运重建治疗过程中的核心环节,如何减轻I/R损伤一直是国际研究热点之一。糖尿病与I/R损伤对心肌都有损害作用,相关研究证明糖尿病能够进一步恶化I/R损伤对心肌的损伤作用。研究表明,缺血预处理(ischemia preconditioning,IPC)可以延缓或减轻心肌I/R损伤,同时,麻醉药预处理(anesthetic induced preconditioning,APC)也具有IPC样的心肌保护作用。其中,七氟烷作为现阶段临床较常用的吸入麻醉药,同样对心肌I/R损伤具有保护作用。本文就七氟烷对糖尿病心肌I/R损伤的影响及其机制做一综述。  相似文献   

13.
The complex [Ru(SB12H11)(NH3)5]·2H2O has been prepared by the reaction of Cs2B12H11SH with [RuCl(NH3)5]Cl2 in aqueous solution. The complex represents the first reported example of the borocaptate anion acting as a ligand. The structure of the complex has been determined by single crystal X-ray diffraction analysis. The crystal parameters are monoclinic, space group P21/c, A = 8.056(1), B = 14.240(2), C = 15.172(2) Å, β=98.48° and Z = 4. The ruthenium atom has a distorted octahedral coordination. The distortion is probably due to the high (3) charge and the large bulk of the borocaptate ligand. These features can also be observed in the spectroscopic properties of the complex.  相似文献   

14.
Protein factor of fertility (PFF) has been measured in seminal plasma by immunodiffusion method with sensitivity about 2 mg/L. It has been found that normal level of PFF was from 16 to 256 mg/L, on the average 45.9 mg/L. Family (husband and wife) has been studied in the genetic laboratory by traditional methods. It has been shown that there is the correlation between low PFF levels in seminal plasma (on the average 15.0 mg/L, i.e. from 2 to 64 mg/L) and several developmental defects of fetus. There were anencephalus, hydrocephalus, spina bifida and other morphological defects (coefficient correlation was P less than 0.01). The biological role of PFF in human developmental defects is discussed.  相似文献   

15.
Alternating copolymer of maleic anhydride (MA) with N-isopropylacrylamide (NIPA) has been synthesized. Spectral characterization of this copolymer has been achieved by FTIR, Raman, 1H, 13C NMR spectroscopic methods. Besides hydrodynamic behavior of the copolymer has been also investigated by viscometric method for comparison with that obtained from the solubility profile through algorithmic calculations. As a consequence of the algorithmic calculations DMSO has been determined as the best solvent for the copolymer, poly(MA-alt-NIPA), which is also supported by the viscometric results.  相似文献   

16.
The N,N-diethylcarbamato derivative of zirconium(IV), Zr(O2CNEt2)4 has been studied by X-ray crystallography. Crystal data: C20H40Na4O8Zr, monoclinic, space group C2/c, a = 14.057(1), b = 12.168(1), c = 16.746(2) Å, β = 108.071(4)°, Z = 4, Dc = 1.356, F(000) = 1168, T = 213 K. The compound is isotypic with the corresponding niobium(IV) derivative with a dodecahedral coordination at the zirconium atom. By reaction of NbCl4(THF)2 with Tl(hfacac), the hexafluoroacetylacetonato derivative of niobium (IV), Nb(hfacac)4, has been prepared and structurally characterized. The compound crystallizes in the orthorhombic space group Pna21 with the following cell constants: a = 10.399(4), b = 15.852(9), c = 119.073(1) Å. It is not isotypic with the corresponding zirconium(IV) derivative, Zr(hfacac)4. Crystal data: C20H4F24O8Zr, monoclinic, space group P21/n, a = 11.974(4), b = 20.451(6), c = 13.140(3) Å, β = 104.487(11)°, Z = 4, Dc = 1.960, F(000) = 1776, T = 223 K. Although in both compounds the central metal atom shows a square antiprismatic coordination, the coordination mode of the ligands is different and slight deviations from the D4(llll) and C2(llss) ideal geometries have been observed in the case of niobium and zirconium, respectively. An EPR study has been performed on the Nb(IV) derivatives as diluted solid solutions in frozen organic solvents or in the diamagnetic matrix of the corresponding zirconium(IV) compound. The EPR spectra have confirmed the presence of non-interacting paramagnets in the solid solutions and, in the case of Nb(O2CNEt2)4, the point symmetry of the paramagnetic centre has been found to be in agreement with the results of the X-ray investigation. An EPR spectrum of rhombic symmetry has been observed for the hexafluoroacetylacetonato derivative of Nb(IV) when diluted in frozen THF solution or in Zr(hfacac)4.  相似文献   

17.
Reaction of LaCl3·7H2O containing small amounts of La(NO3)3·7H2O as an impurity with 12-crown-4 or 18-crown-6 in 3:1 CH3CN:CH3OH resulted in the isolation of the mixed anion complexes [LaCl2(NO3)(12-crown-4)]2, [La(NO3)(OH2)4(12-crown-4)]Cl2·CH3CN and [LaCl2(NO3)(18-crown-6)]. The nine-coordinate dimer, [LaCl2(NO3)(12-crown-4)]2, has all of the anions in the inner coordination sphere and La3+ has a capped square antiprismatic geometry. It crystallizes in the orthorhombic space group Pbca with (at −150 °C) a = 12.938(6), B = 15.704(3), C = 13.962(2) Å, and Dcalc = 2.08 g cm−3 for Z = 4. The second complex isolated from the same reaction, [La(NO3)(OH2)4(12-crown-4)]Cl2·CH3CN, has the bidentate nitrate anion in the inner coordination sphere but the two chloride anions are in a hydrogen bonded outer sphere. This complex is ten-coordinate 4A,6B-expanded dodecahedral and crystallizes in the monoclinic space group P21 with (at 20 °C) A = 7.651(2), B = 11.704(7), C = 11.608(4) Å, β = 95.11(2)°, and Dcalc = 1.80 g cm−3 for Z = 2. The 18-crown-6 complex, [LaCl2(NO3)(18-crown-6)], has all inner sphere anions and has ten-coordinate 4A,6B-expanded dodecahedral La3+ centers. It crystallizes in the orthorhombic space group Pbca with (at 20 °C) a = 14.122(7), B = 13.563(5), C = 19.311(9) Å, and Dcalc = 1.89 g cm−3 for Z = 8.  相似文献   

18.
A method for the dry-preservation of fixed plant material, root tips and buds, is described. The method seems to be advantageous on long expeditions and when material has to be sent away.

The material is transferred from the fixative to 70% alcohol (3 changes, 1/2 hour in the last). It is dried on blotting-paper. The dried material may be preserved a long time. Material kept dry for 4 1/2 years has proved to be quite satisfactory. Drying has been tried after fixation with CRAF-solutions (Webber and Randolph modifications) and fixatives containing osmic acid (Fleming-Benda and 2BD).

The dry material is swollen by keeping for 2 days in 10% alcohol. It is embedded in paraffin according to the usual method. A satisfactory staining has been obtained after these fixatives using iodine-gentian-violet and Feulgen stainings. In addition to chromosome counts dry material may be used for chromosome morphology studies.

Dried material fixed in aceto-alcohol (1:3) has not turned out to be specially suitable for squash preparations owing to the fragility of the chromosomes. If strong pressure is not applied, satisfactory results may, however, be obtained.  相似文献   

19.
The second human calcitonin/CGRP gene is located on chromosome 11   总被引:6,自引:0,他引:6  
Summary A second human calcitonin/calcitonin gene related peptide (hCT/CGRP) gene has been identified. This second hCT/CGRP gene has been shown to contain sequences highly homologous to exons 3, 5 (CGRP-encoding), and 6 of the first hCT/CGRP gene, but sequences closely related to exon 4 (CT-encoding) could not be demonstrated. Southern blot hybridization analysis of DNA from human-rodent somatic cell hybrids showed that the second hCT/CGRP gene is located in the q12-pter region of chromosome 11. The first hCT/CGRP gene has previously been assigned to the p13–p15 region of chromosome 11.  相似文献   

20.
The combination of Quantum Mechanics (QM) and Molecular Mechanics (MM) methods has become an alternative tool for many applications for which pure QM and MM are not suitable. The QM/MM method has been used for different types of problems, for example: structural biology, surface phenomena, and liquid phase. In this paper, we have used these methods for antibiotics and then we compare results. The calculations were done by the full ab initio method (HF/3-21G) and the (HF/STO-3G) and QM/MM (ONIOM) method with HF (3-21G)/AM1/UFF and HF (STO-3G)/AM1/UFF. We found the geometry that has obtained by the QM/MM method to be very accurate, and we can use this rapid method in place of time consuming ab initio methods for large molecules. Comparison of energy values in the QM/MM and QM methods is given. In the present work, we compare chemical shifts and conclude that the QM/MM method is a perturbed full QM method. The work has been done on penicillin, streptomycin, benzyl penicillin, neomycin, kanamycin, gentamicin, and amoxicillin.  相似文献   

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