云南壮异蝽属及娇异蝽属新种记述(半翅目:异蝽科)

云南地区的壮异蝽属(Urochela Dallas)和娇异蝽属(Hrostylis Westwood)截止到目前共记录23种。本文记述了在该省西部地区发现的5新种,现描述如下。模式标本保存于天津南开大学生物系。 钩壮异蝽Urochela hamata,新种(图1,2) 体黄褐色,具黑褐色花斑及黑色刻点。触角第4节中部及第5节基半部为淡黄色;     

The isolation and partial characterization of precursor forms of ostrich carboxypeptidase

Ostrich carboxypeptidases A and B were recently purified and characterized. The aim of this study was to isolate and purify, and partially characterize in terms of molecular weight, pI, amino acid composition and N-terminal sequencing, the precursor forms of carboxypeptidases from the ostrich pancreas. Inhibition studies with soybean trypsin inhibitor and activation studies with three proteases (bovine trypsin, bovine chymotrypsin and porcine elastase) were performed on crude ostrich acetone powder and the carboxypeptidase A and B activities were determined. SDS-PAGE was carried out after every incubation to monitor the rate and degree of conversion of a M(r) 66K component to procarboxypeptidase and carboxypeptidase A and B. The precursor forms were purified by Toyopearl Super Q and Pharmacia Mono Q chromatography. All three proteases converted the M(r) 66K component to procarboxypeptidases and carboxypeptidases over a set time interval, with carboxypeptidase A and B activities being detected in the acetone powder. Chymotrypsin was the preferred protease since it exhibited a more controlled activation of the procarboxypeptidases. The amino acid composition of procarboxypeptidase A revealed 525 residues. The N-terminal sequence of procarboxypeptidase A showed considerable homology when compared with several other mammalian sequences. M(r) and pI values of 52K and 5.23 were obtained for procarboxypeptidase A, respectively. This study indicated that ostrich procarboxypeptidase A is closely related to other mammalian procarboxypeptidase A molecules in terms of physicochemical properties.     

恒河猴二次接种H5N1亚型禽流感病毒

对恒河猴进行二次接种H5N1亚型禽流感病毒试验,并对二次接毒的结果进行观察,评估初次接毒对恒河猴二次接毒效果的影响.首次接种试验中,3、4、5号恒河猴用环甲膜穿刺注射方法接种含有H5N1亚型禽流感病毒的尿囊液,6号猴接种不含病毒的尿囊液.90d后,再次用环甲膜穿刺注射方法二次接种,4、5、6号猴接种7mlTCID50浓度为104.875病毒的尿囊液,3号猴接种7ml不含病毒的尿囊液.进行抗体等检测,并分别于72h无痛处死3、4、6号猴,第7d无痛处死5号猴,进行肺的病毒检测及病理观察.结果显示,3、4、5号猴至试验结束时体内依然有较高的抗H5N1亚型禽流感病毒抗体水平,6号猴没有抗体;通过RT-PCR以及免疫组化染色进行病毒检测,均只在6号猴肺部检出病毒,且6号猴肺部病理损伤最为严重.由此可以得出初步结论:在初次感染H5N1亚型禽流感病毒后90d,临床症状已基本恢复正常的恒河猴体内仍然有较高水平的抗体,此时,恒河猴抵抗H5N1亚型禽流感病毒二次感染的能力显著提高.     

Intraclonal polymorphism in the bacterium Streptomyces ambofaciens ATCC23877: evidence for a high degree of heterogeneity of the wild type clones

In Streptomyces ambofaciens a genetic instability generates a high degree of polymorphism consisting of four main phenotypes: pigmented colonies (Pig(+) qualified as WT phenotype), pigment-defective colonies, pigmented colonies with pigment-defective sector and pigmented colonies with pigment-defective papillae. Molecular analysis of Pig(col)(-) and Pig(sec)(-) (pigment-defective mutant derived from a colony and a sector, respectively) produced by genetic instability and isolated in five Pig(+) subclones progenies revealed a new aspect of polymorphism in S. ambofaciens ATCC23877. Frequencies of Pig(col)(-) and Pig(sec)(-) mutants deleted at the chromosome ends varied from one WT progeny to another. Two main types of deleted mutants were observed: deleted for one or both chromosomal extremities. The relative proportion of these two categories differed according to the WT progeny. These results argue for heterogeneity of the WT clones, i.e., Pig(+) colonies, originated from S. ambofaciens ATCC23877.     

肿瘤坏死因子-α和白介素-2对成骨细胞增殖的影响

成骨细胞在骨组织改建中至关重要。本试验体外培养人骨肉瘤细胞系MG63,MTT方法检测白介素-2(Interleukin-2,IL-2)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)对成骨细胞增殖的影响。结果表明,当IL-2的浓度大于100U/mL,其能够促进成骨细胞增殖(P0.05),一定浓度(50～1000U/mL)的TNF-α对成骨细胞的增殖也有促进作用。     

New microsatellite loci in the dwarf yams Dioscorea group Epipetrum (Dioscoreaceae)

? Premise of the study: Microsatellite loci were isolated and characterized from enriched genomic libraries of two taxa of the Chilean Epipetrum group of Dioscorea to assess their levels of genetic diversity and population differentiation. ? Methods and Results: Eleven microsatellite loci were identified. Six out of nine microsatellites from D. biloba amplified in D. humilis, and the two microsatellites from D. humilis amplified in both taxa. Two different sets of eight loci amplified in each of the two tested taxa, D. biloba and D. humilis. The average number of alleles was 5.75 and 5 for D. biloba and D. humilis, respectively. Higher levels of mean genetic diversity were found in D. biloba (H(E) = 0.639) than in D. humilis (H(E) = 0.414). ? Conclusions: These microsatellite primers will be useful in population genetic studies and to establish conservation strategies in the endangered taxa of the Epipetrum group of Dioscorea.     

Heart-specific Deletion of CnB1 Reveals Multiple Mechanisms Whereby Calcineurin Regulates Cardiac Growth and Function

Calcineurin is a protein phosphatase that is uniquely regulated by sustained increases in intracellular Ca²⁺ following signal transduction events. Calcineurin controls cellular proliferation, differentiation, apoptosis, and inducible gene expression following stress and neuroendocrine stimulation. In the adult heart, calcineurin regulates hypertrophic growth of cardiomyocytes in response to pathologic insults that are associated with altered Ca²⁺ handling. Here we determined that calcineurin signaling is directly linked to the proper control of cardiac contractility, rhythm, and the expression of Ca²⁺-handling genes in the heart. Our approach involved a cardiomyocyte-specific deletion using a CnB1-LoxP-targeted allele in mice and three different cardiac-expressing Cre alleles/transgenes. Deletion of calcineurin with the Nkx2.5-Cre knock-in allele resulted in lethality at 1 day after birth due to altered right ventricular morphogenesis, reduced ventricular trabeculation, septal defects, and valvular overgrowth. Slightly later deletion of calcineurin with the α-myosin heavy chain Cre transgene resulted in lethality in early mid adulthood that was characterized by substantial reductions in cardiac contractility, severe arrhythmia, and reduced myocyte content in the heart. Young calcineurin heart-deleted mice died suddenly after pressure overload stimulation or neuroendocrine agonist infusion, and telemetric monitoring of older mice showed arrhythmia leading to sudden death. Mechanistically, loss of calcineurin reduced expression of key Ca²⁺-handling genes that likely lead to arrhythmia and reduced contractility. Loss of calcineurin also directly impacted cellular proliferation in the postnatal developing heart. These results reveal multiple mechanisms whereby calcineurin regulates cardiac development and myocyte contractility.     

The costal skeleton of Homo antecessor: preliminary results

The Lower Pleistocene TD6 level at the Gran Dolina site in the Sierra de Atapuerca (Burgos, Spain) has yielded nine ribs that represent a minimum of three individuals of the species, Homo antecessor. We present a detailed morphological and metric study of these costal elements, including the siding and anatomical position of all of the rib remains. The adult or nearly adult ribs are also metrically compared with other fossil hominins and with modern comparative samples. The costal elements recovered to date from the TD6 level at Gran Dolina can neither confirm nor reject the hypothesis that H. antecessor had a large thorax, similar to that of Neandertals. However, the fragmentary evidence of the H. antecessor thoracic skeleton is not inconsistent with this suggestion based on other skeletal elements, such as clavicles.

Resumen

En el nivel TD6 del Pleistoceno inferior del yacimiento de Gran Dolina, en la Sierra de Atapuerca (Burgos, España) se han recuperado nueve costillas que pertenecen a un mínimo de tres individuos de la especie Homo antecessor. Presentamos un detallado estudio métrico y morfológico incluyendo el lado y la determinación anatómica. Las costillas pertenecientes a individuos adultos o casi adultos también son comparadas métricamente a muestras modernas de comparación y otros homininos fósiles. Basándonos en el registro de costillas de Homo antecessor recuperado hasta el momento no podemos probar ni refutar la hipótesis de que esta especie presentaba un tórax grande similar al de los Neandertales. Sin embargo, el registro de costillas no es inconsistente con la hipótesis de un tórax grande como sugiere la gran longitud de sus clavículas.     

A B3LYP and MP2(full) theoretical investigation into cooperativity effects,aromaticity and thermodynamic properties in the Na+⋯benzonitrile⋯H2O ternary complex

In this work the growth of a graphene monolayer on copper substrate, as typically achieved via chemical vapor deposition of propene (C₃H₆), was investigated by first-principles and kinetic Monte Carlo calculations. A comparison between calculated C1s core-level binding energies and electron spectroscopy measurements showed that graphene nucleates from isolated carbon atoms adsorbed on surface defects or sub-superficial layers upon hydrocarbon fragmentation. In this respect, ab initio nudged elastic band simulations yield the energetic barriers characterizing the diffusion of elemental carbon on the Cu(111) surface and atomic carbon uptake by the growing graphene film. Our calculations highlight a strong interaction between the growing film edges and the copper substrate, indicative of the importance of the grain boundaries in the epitaxy process. Furthermore, we used activation energies to compute the reaction rates for the different mechanisms occurring at the carbon–copper interface via harmonic transition state theory. Finally, we simulated the long-time system growth evolution through a kinetic Monte Carlo approach for different temperatures and coverage. Our ab initio and Monte Carlo simulations of the out-of-equilibrium system point towards a growth model strikingly different from that of standard film growth. Graphene growth on copper turns out to be a catalytic, thermally-activated process that nucleates from carbon monomers, proceeds by adsorption of carbon atoms, and is not self-limiting. Furthermore, graphene growth seems to be more effective at carbon supersaturation of the surface—a clear fingerprint of a large activation barrier for C attachment. Our growth model and computational results are in good agreement with recent X-ray photoelectron spectroscopy experimental measurements.