化石

我是新的化石爱好者。收藏化石不到一年时间。但有幸身处辽西化石产地 ,得天独厚 ,因而收集了一些化石标本。《化石》使我学到了不少知识。现赋诗一首 :凝固瞬时间 ,形成上亿年。千姿鱼戏水 ,百态鸟冲天。昂首恐龙绝 ,缩头龟鳖延。新生随旧天 ,化石解从前化石@陈耕普!辽宁锦州市古塔区宜昌路三段42-9号     

化石？化石!

分层的岩石，从远古到如今 古希腊哲学家色诺芬尼（约公元前560—478）是已知最早对化石进行描述的人，并且推测出化石是生物的遗迹。他在意大利西西里岛的采石场发现了鱼的化石，又在马耳他岛发现了海洋软体动物的化石，他得出结论说，山脉必定曾经位于海中，并认为地球在历史上多次交替出现世界性大洪水和干涸。亚里士多德在《气象学》一书中，更详细地阐述了类似的“沧桑”观点：     

化石文化

化石文化刘晓峰化石,大自然赐予人类的珍贵资源之一,历来为人类所关注。化石给人类带来了丰富多彩的生活,并从中创造和累积了独特的文化──化石文化。－、化石文化的含义化石,是经自然作用保存在各地质历史时期岩层中的生物遗体或遗迹。化石文化是人类在发现、认识、...     

粪化石

粪化石（coprolite）指石化的脊椎动物的排泄物,它是化石中的珍品。常见的有鱼、爬行动物、哺乳动物的粪化石。而恐龙的粪化石却不多见。恐龙专家彭光照曾在《化石》1998年第4期撰写“恐龙的粪便”一文,介绍了圣巴巴加州大学的女研究生陈卡伦在蒙大拿洛基斯博物馆实验室工作时,该馆恐龙专家霍勒尔告诉她一些他认为可能是7500万年前鸭嘴龙的粪便化石。     

假化石

系指成因与生物毫无关系而在地层中存在的某些物体或构造，易被误为化石。常见的假化石有结核类（包括燧石结核、僵石）、树枝石、龟鳖化石，另有人常把地层中所含有不规则石块或华误为牙齿化石。假化石@大地     

化石鉴宝

《化石》编辑同志我是《化石》杂志忠实读者,与《化石》相伴十几个年头了,我每次拿到新的一期时,心里有说不出的高兴,上面的文章我都是认真读完,收益很大。2005年《化石》改版,也是我心中所想的,我认为还要大胆地改,上面给非专业人员留一席之地,让《化石》爱好者谈自己的见解,再搞专家点评,投稿人多了,出版加快,季刊就可以改成双月刊或月刊,等三个月真着急啊。本人收藏了两个化石,不知是何物,我向专家请教过没有回信,几年来无处问询,好在《化石鉴宝》专栏开辟给了我一个向专家请教机会,感谢《化石》杂志。湖南省辰溪县轻工业局刘承泽2005·3…     

化石用途种种

化石是多种多样的:有人类化石,无脊椎动物化石,脊椎动物化石,植物化石,微体古生物化石,细菌化石……等等。那么,化石有哪些用途呢? 化石的用途很多。让我们简单地从以下几个方面谈一谈吧。 (一)对生物进化论的贡献 1883年8月,达尔文在南美阿根廷的朋塔阿耳塔地区发现了很多巨大的陆生动物遗骸。其中有大懒兽、磨齿兽以及被达尔文称之为“最     

植物化石类型

1　压型化石　植物遗传体在沉积物中被压实而呈扁实状态 ,随着细胞的压扁 ,内部的结构随之消失 ,常常留下一层与植物残骸原形一致的碳质薄膜 ,这种化石类型称为压型化石 ,是最常见的植物化石类型。在压型化石上植物叶片表皮层、气孔等的细胞形态均可完好保存。2　印痕化石　印痕化石是植物遗体在埋葬前陷落在松软细密的底质上的印迹。由于植物遗体在埋葬时业已消失 ,所以印痕化石很少或不粘附碳质。从印痕化石上不能看到细胞的细节 ,但却能发现植物体的主要特征 ,如通过植物叶片的印痕化石可知叶形、脉序等特征。3　模型化石　立体的植物器…     

化石趣闻

什么是化石,这已是人所共知的事情了。但您可知道,最早的化石定义却比现在的含义广泛得多。十八世纪初,人们把地下挖出的任何物体,不论它是岩石、还是矿物,或者其它什么东西,都统统称为“化石”。因此,当时的地质学家就将拉丁文“挖出”(fossilis)一词,转用于化石。但过了不久,人们认识到把岩石,矿物和古生物遗骸统称为“化石”有点混乱,就把化石(fossil)一词的含义只限于岩石中遗留下来的动植物遗体。     

进化·启示录 化石?化石!

分层的岩石,从远古到如今古希腊哲学家色诺芬尼(约公元前560-478)是已知最早对化石进行描述的人,并且推测出化石是生物的遗迹。他在意大利西西里岛的采石场发现了鱼的化石,又在马耳他岛发现了海洋软体动物的化石,他得出结论说,山脉必定曾经位于海中,并认为地球在历史上多次交     

Simultaneous measurement of the trace elements Al, As, B, Be, Cd, Co, Cu, Fe, Li, Mn, Mo, Ni, Rb, Se, Sr, and Zn in human serum and their reference ranges by ICP-MS

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.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

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.     

Reference values for the concentrations of As,Cd, Co,Cr, Cu,Fe, I,Hg, Mn,Mo, Ni,Pb, Se,and Zn in selected human tissues and body fluids

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.     

Crystal structure, detonation performance, and thermal stability of a new polynitro cage compound: 2, 4, 6, 8, 10, 12, 13, 14, 15-nonanitro-2, 4, 6, 8, 10, 12, 13, 14, 15-nonaazaheptacyclo [5.5.1.13, 11. 15, 9] pentadecane

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.     

Monovalent Cation Permeation through the Connexin40 Gap Junction Channel : Cs,Rb, K,Na, Li,TEA, TMA,TBA, and Effects of Anions Br,Cl, F,Acetate, Aspartate,Glutamate, and NO3

The unitary conductances and permeability sequences of the rat connexin40 (rCx40) gap junction channels to seven monovalent cations and anions were studied in rCx40-transfected neuroblastoma 2A (N2A) cell pairs using the dual whole cell recording technique. Chloride salt cation substitutions (115 mM principal salt) resulted in the following junctional maximal single channel current-voltage relationship slope conductances (γ_j in pS): CsCl (153), RbCl (148), KCl (142), NaCl (115), LiCl (86), TMACl (71), TEACl (63). Reversible block of the rCx40 channel was observed with TBA. Potassium anion salt γ_j are: Kglutamate (160), Kacetate (160), Kaspartate (158), KNO₃ (157), KF (148), KCl (142), and KBr (132). Ion selectivity was verified by measuring reversal potentials for current in rCx40 gap junction channels with asymmetric salt solutions in the two electrodes and using the Goldman-Hodgkin-Katz equation to calculate relative permeabilities. The permeabilities relative to Li⁺ are: Cs⁺ (1.38), Rb⁺ (1.32), K⁺ (1.31), Na⁺ (1.16), TMA⁺ (0.53), TEA⁺ (0.45), TBA⁺ (0.03), Cl⁻ (0.19), glutamate⁻ (0.04), and NO₃− (0.14), assuming that the monovalent anions permeate the channel by forming ion pairs with permeant monovalent cations within the pore thereby causing proportionate decreases in the channel conductance. This hypothesis can account for why the predicted increasing conductances with increasing ion mobilities in an essentially aqueous channel were not observed for anions in the rCx40 channel. The rCx40 effective channel radius is estimated to be 6.6 Å from a theoretical fit of the relationship of relative permeability and cation radius.     

Relations of the Al,B, Ba,Br, Ca,Cl, Cu,Fe, K,Li, Mg,Mn, Na,P, S,Si, Sr,and Zn mass fractions to morphometric parameters in pediatric and nonhyperplastic young adult prostate glands

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.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

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.     

Potential Compounds for Oral Cancer Treatment: Resveratrol,Nimbolide, Lovastatin,Bortezomib, Vorinostat,Berberine, Pterostilbene,Deguelin, Andrographolide,and Colchicine

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.