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1.
广西天等把荷剖面下泥盆统埃姆斯阶产较丰富的Polygnathus属牙形刺化石。经详细鉴定,共识别出Polygnathus inversus,Pol.gilberti,Pol.laticostatus,Pol.linguiformis bultyncki,Pol.nothoperbonus,Pol.perbonus,Pol.serotinus,Pol.vigierei等11种(含1个未定种和2个相似种)。根据牙形刺的特征和地层分布,自下而上划分为3个牙形刺带,即nothoperbonus带、inversus带和serotinus带。在系统分类研究的基础上,根据剖面中牙形刺产出层位及齿台口面和反口面特征分析,Pol.serotinus可能由Pol.vigierei通过外齿台边缘的抬升、外侧近脊沟的变宽变深以及齿台前缘的逐渐平行演化而来,Polygnathus属反口面基腔翻转的特征最早出现在Pol.nothoperbonus演化阶段。 相似文献
2.
海南岛晚泥盆世—早石炭世牙形刺 总被引:1,自引:0,他引:1
作者描述了海南岛昌江县石碌地区昌江组首次发现的牙形刺Palmatolepis gracilis gracilis Bransonet Me-hl,P.gracilis sigmoidalis Ziegler,Polygnathus ansatus Ziegleret Klapper,Polynodosus germanus(UlrichetBassler),Neopolygnathus dentatus(Druce)等和白沙县金波地区南好组第二段的Siphonodella levis(Ni),Polygnathus cf. inornatus Branson等,共8属20种,并据此将含化石地层分别确定为晚泥盆世法门期和早石炭世杜内期早期。指出以往认为是中泥盆统吉维特阶带化石Polygnathus ansatus Ziegleret Klapper与法门期牙形刺化石共同出现于昌江组并非构造混杂所致,但并不排除可能是化石再沉积作用的原因。同意将Polynodosus属从Polygnathus属中分离出来,在我国首次采用Polynodosus。 相似文献
3.
在大兴安岭乌奴耳地区发现两个牙形刺动物群。一个采自北矿组,牙形刺Caudicriodus angulatus cf.cauda指示北矿组的时代为Eifelian早期。另一个样品采自霍博山组(大民山组)上部的角砾岩层,产有牙形刺的混合动物群。Palmatolepis hassi,Pal.ljashenkovae,Pal.kireevae,Pal.subrecta,Polygnathus decorosus,Icriodus ex-pansus,I.symmetricus等牙形刺主要来自Frasnian晚期晚rhenana带。而Ancyrodella binodosa,Ancyrodella nodosa,Schimitognathus cf.hermanni则主要来自Gevitian期晚期和Frasnian期早期;Ancyrognathus ubiquitus是重要的事件种,见于linguiformis带至早triangularis带(F/F界线层);这个角砾岩层最后形成的时代可能是早triangularis带,含有多层位的再沉积的牙形刺。文中共描述了牙形刺11属22种,包括2个未定新种和1个未定种。 相似文献
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本文系统研究了贵州独山马道剖面泥盆-石炭纪之交的牙形刺,共鉴定出6属25种(包括亚种、比较种、未定亚种)。根据牙形刺的产出情况,在该剖面自下而上可以识别出3个牙形刺带,即法门阶的Bispathodus ultimus带,杜内阶的Siphonodella isosticha带和Polygnathus communis carina带。基于详细的牙形刺材料,讨论了上述生物带的时限和范围,并与其他地区进行了对比。虽然尚未在本剖面找到泥盆-石炭系界线的标志分子Siphonodella sulcata,但综合考虑其他牙形刺的分布以及岩性变化特征,可以将泥盆-石炭系界线暂置于融县组上部白云岩段的底部。以上成果将加深对于这一层段的牙形刺面貌以及牙形刺生物带的理解,也将为开展华南泥盆-石炭系界线再研究以及泥盆-石炭纪之交的生物-环境事件研究提供借鉴。 相似文献
5.
略阳组分布于南秦岭勉略缝合带附近,是略阳地区重要的岩石地层单元。本次研究在略阳灵岩寺南部剖面的略阳组获得牙形刺13枚,共识别出3属5种,包含2亚种和2未定种,分别为:Siphonodella homosimplex,Polygnathus communis communis,Po.inornatus inornatus,Po. sp.和Pseudopolygnathus sp.。该牙形刺组合可以与华南同时期牙形刺进行对比,时代为早石炭世杜内期早期,这为确定略阳组的下部层位的具体时代提供了新的牙形刺证据。略阳组中所产出的Si.homosimplex为华南地区浅水相牙形刺的典型代表,Po.inornatus inornatus广泛见于西欧的浅水相地层,这表明在早石炭世期间勉略地区为浅水碳酸盐岩台地沉积环境,且与华南地区生物区系存在紧密联系,同前人根据底栖生物化石研究得出的结论相一致。 相似文献
6.
《微体古生物学报》2016,(4)
世界泥盆系洛霍考夫阶和布拉格阶牙形刺生物地层有较明显的地理分区性,区域对比较困难,中国缺少连续的布拉格阶与洛霍考夫阶灰岩相剖面,牙形刺生物地层的研究,仍很不完善。广西南宁大沙田剖面是目前所知布拉格阶灰岩最多的剖面,在其下部发现了牙形刺Eognathodus irregularis,E.nagaolingensis,E.sulcatus mu morphs,Masaraella pandora(Murphy,Matti et Walliser,1981)W morphotype P element,其时代为布拉格期早期,大致相当于北美的Eognathodus irregularis-Gondwania profunda带和欧洲的E.sulcatus带。中布拉格期牙形刺Pseudogondwania kindlei带,还没有确立。晚布拉格期的牙形刺Polygnathus pirenniae带的存在和时限范围也没有在大沙田剖面得到确定。但大沙田剖面那高岭组的时代属布拉格期早期是肯定的。 相似文献
7.
渝东南地区泥盆纪牙形刺及其地层意义 总被引:2,自引:0,他引:2
本文研究了渝东南地区3个泥盆纪剖面的牙形刺,黔江濯水剖面的顶部(第7层)产有Palmatolepis quadrantinodosalobata等牙形刺,时代为法门期早期Middle crepida带至Lower rhomboidea带,是本区泥盆纪海相沉积的最高层位;酉阳兴隆剖面(第51层)发现牙形刺Palmatolepis semichatovae等牙形刺,时代为弗拉斯期晚期Lower rhenana带;濯水剖面的5层和6层、黔江水泥厂剖面的5层至7层以及酉阳兴隆剖面的52层和53层均产有较多的弗拉斯期晚期的牙形刺。本区写经寺组、黄家磴组和云台观组都可能是穿时的,写经寺组在各剖面残留厚度不同。写经寺组的时代为弗拉斯期晚期至法门期早期。本区缺少法门期中、晚期的典型的海相沉积。描述了一个新种Polygnathus chongqingensis Wang sp.nov.。 相似文献
8.
二塘组是俞昌民、殷保安(1978)建立的,广泛分布于广西中部的武宣-象州地区,层型剖面在武宣二塘六卜岭西,屯头村至六峰山林场之间.嗣后,俞昌民、邝国敦对二塘组四射珊瑚进行了研究,建立了 Lyrielasma guangxiense 组合带(俞昌民等,1980).王成源(1981)报道了二塘组上段产出的牙形刺 Polygnathus perbonus, 相似文献
9.
二塘组是俞昌民、殷保安(1978)建立的,广泛分布于广西中部的武宣-象州地区,层型剖面在武宣二塘六卜岭西,屯头村至六峰山林场之间。嗣后,俞昌民、邝国敦对二塘组四射珊瑚进行了研究,建立了Lyrielasma guangxiense组合带(俞昌民等,1980)。王成源(1981)报道了二塘组上段产出的牙形刺Polygnathus perbonus,进一步确认了二塘组的层位。1978年,许汉奎曾 相似文献
10.
本文系统地回顾了日本志留纪至三叠纪牙形刺研究的历史和现在的成果。志留纪牙形刺只有少数零星的报道,没有建立化石带;早泥盆世已建立了5个牙形刺组合,没有中、晚泥盆世的记录;石炭纪有8个牙形刺带,其中晚石炭世3个牙形刺带;二叠纪5个牙形刺带或动物群,其中,中、晚二叠世各1个带(动物群);三叠纪可划分出14个牙形刺带。 相似文献
11.
A new polynitro cage compound 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptcyclo [5.5.1.1(3,11).1(5,9)] pentadecane (NNNAHP) was designed in the present work. Its molecular structure was optimized at the B3LYP/6-31 G(d,p) level of density functional theory (DFT) and crystal structure was predicted using the Compass and Dreiding force fields and refined by DFT GGA-RPBE method. The obtained crystal structure of NNNAHP belongs to the P-1 space group and the lattice parameters are a = 9.99 ?, b = 10.78 ?, c = 9.99 ?, α = 90.01°, β = 120.01°, γ = 90.00°, and Z = 2, respectively. Based on the optimized crystal structure, the band gap, density of state, thermodynamic properties, infrared spectrum, strain energy, detonation characteristics, and thermal stability were predicted. Calculation results show that NNNAHP has detonation properties close to those of CL-20 and is a high energy density compound with moderate stability. 相似文献
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Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons. 相似文献
14.
The variation with age of the 18 trace element mass fractions and some histological characteristics of intact prostate glands of 50 subjects aged 0–30 years was investigated by instrumental neutron activation analysis, inductively coupled plasma atomic emission spectrometry, and a quantitative morphometric analysis. Mean values ± standard error of the mean (M ± SΕΜ) for the mass fractions (in milligrams per kilogram wet tissue) of these trace elements in pre-puberty were: Al 28.5 ± 9.0, B 0.40 ± 0.11, Ba 1.48 ± 0.44, Br 10.5 ± 1.5, Ca 241 ± 30, Cl 3,203 ± 278, Cu 3.51 ± 0.89, Fe 33.7 ± 4.1, K 2,364 ± 145, Li 0.020 ± 0.004, Mg 153 ± 23, Mn 0.46 ± 0.06, Na 2,286 ± 130, P 1,391 ± 100, S 1,698 ± 132, Si 62 ± 11, Sr 0.38 ± 0.08, and Zn 27.6 ± 2.3. During puberty and postpuberty, when there is a significant increase in circulating androgens, the mean values were: Al 7.2 ± 1.4, B 0.21 ± 0.05, Ba 0.25 ± 0.06, Br 5.8 ± 1.0, Ca 433 ± 81, Cl 2,314 ± 201, Cu 1.77 ± 0.13, Fe 20.9 ± 1.6, K 2,585 ± 118, Li 0.0088 ± 0.0014, Mg 232 ± 27, Mn 0.34 ± 0.04, Na 1,875 ± 107, P 1,403 ± 98, S 1,673 ± 73, Si 22.2 ± 3.1, Sr 0.22 ± 0.03, and Zn 93.3 ± 8.9. Mean values (M ± SΕΜ) of percent volumes (%) of the stroma, epithelium and lumen in the prostate before puberty were 73.4 ± 2.6, 20.4 ± 1.7, and 4.45 ± 0.94, respectively, versus 46.5 ± 2.5, 38.5 ± 1.9, and 14.9 ± 1.2 during puberty and postpuberty. This work’s results confirm that the Zn mass fraction in prostate tissue is an androgen-dependent parameter. For the first time it has been demonstrated that the glandular lumen is a main pool of Ca, Mg, and Zn accumulation and that the stroma is a main pool of Al, B, Ba, Br, Cl, Cu, Fe, Mn, Na, and Si accumulation in the normal human prostate, for the age range 0–30 years. It was concluded that the Ca, Mg, and Zn binds tightly within the prostatic fluid, because the volume of glandular lumen reflects the volume of prostatic fluid. 相似文献
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The goal of this article was to establish reference ranges of the concentration of trace elements in human serum and to compare
these results with those reported by other authors. We describe the sample preparation and measurement conditions that allow
the rapid, precise, and accurate determination of Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human
serum samples (n=110) by inductively coupled plasma-mass spectrometry (ICP-MS). Accuracy and precision were determined by analyzing three
reconstituted reference serum samples by comparison with other methods and by the standard addition procedure.
The advantages of the ICP-MS method include short time of analysis of the elements mentioned, low detection limit, high precision,
and high accuracy. Disadventages include a high risk of contamination due to the presence of some of the elements of interest
in the environment, the relatively delicate sample handling, and the high cost of the equipment. 相似文献
16.
G. V. Iyengar 《Biological trace element research》1987,12(1):263-295
This report attempts to formulate reference ranges of elemental concentrations for 15 trace elements in selected human tissues
and body fluids.
A set of samples consisting of whole blood, blood serum, urine, milk, liver, and hair were chosen and considered for 15 elements
of biological significance: As, Cd, Co, Cr, Cu, F, Fe, I, Hg, Mn, Mo, Ni, Pb, Se, and Zn. The results represent wholly or
partially data received from 40 countries of the global regions of Africa, Asia, Europe, North, South, and Central America,
Australia, and New Zealand.
This survey, even if qualitative, has been useful in demonstrating certain trends of trace-element scenarios around the world.
It is of course recognized that both diet and environment exert a strong influence on the distribution pattern of several
elements, such as As, Cd, Mn, Pb, Se, and Zn. A limited comparison of the available information on soil status of different
countries reflected some interesting associations for elements, such as Mn and Zn.
Importantly, this study revealed that only a few countries were in a position to identify a reasonable amount of data on samples
requested for this project. Regretably, for a number of countries, any dependable data for even such essential elements as
Cu, Fe, and Zn were not available.
In view of the nutritional importance of many elements, the time is ripe for concerted efforts by intergovernmental agencies
to initiate investigations or commission task forces/projects to generate reliable reference data for selected global regions,
which sadly lack data of any kind at present. 相似文献
17.
Vladimir Zaichick Sofia Zaichick Vasilii Karandashev Sergey Nosenko 《Biological trace element research》2009,129(1-3):107-115
The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs. 相似文献
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Oral cancer is one of the main causes of cancer-related deaths in South-Asian countries. There are very limited treatment options available for oral cancer. Research endeavors focused on discovery and development of novel therapies for oral cancer, is necessary to control the ever rising oral cancer related mortalities. We mined the large pool of compounds from the publicly available compound databases, to identify potential therapeutic compounds for oral cancer. Over 84 million compounds were screened for the possible anti-cancer activity by custom build SVM classifier. The molecular targets of the predicted anti-cancer compounds were mined from reliable sources like experimental bioassays studies associated with the compound, and from protein-compound interaction databases. Therapeutic compounds from DrugBank, and a list of natural anti-cancer compounds derived from literature mining of published studies, were used for building partial least squares regression model. The regression model thus built, was used for the estimation of oral cancer specific weights based on the molecular targets. These weights were used to compute scores for screening the predicted anti-cancer compounds for their potential to treat oral cancer. The list of potential compounds was annotated with corresponding physicochemical properties, cancer specific bioactivity evidences, and literature evidences. In all, 288 compounds with the potential to treat oral cancer were identified in the current study. The majority of the compounds in this list are natural products, which are well-tolerated and have minimal side-effects compared to the synthetic counterparts. Some of the potential therapeutic compounds identified in the current study are resveratrol, nimbolide, lovastatin, bortezomib, vorinostat, berberine, pterostilbene, deguelin, andrographolide, and colchicine. 相似文献