高铁酸钾氧化去除饮用水中微量苯酚的研究

采用次氯酸盐氧化法合成高铁酸钾,测试了其对水中苯酚的氧化去除效果及其影响因素.结果表明,苯酚的去除效率主要取决于高铁酸钾和苯酚的质量比.在酸性条件下高铁酸钾对苯酚的去除效果较好.高铁酸钾与苯酚反应主要发生在最初的几分钟时间内,是一个由快而慢的过程.     

滚环DNA扩增的原理、应用和展望

滚环DNA扩增 (rollingcircleDNAamplification ,RCA)是一种等温信号扩增方法 ,其线性扩增倍数为 1 0 ⁵,指数化扩增能力大于 10⁹,产生的扩增产物连接在固相支持物 (如玻片、微孔板等 )表面的DNA引物或抗体上。RCA是一种适合在芯片上 (on chip)进行信号扩增的新技术 ,它既能提供研究分析的敏感性和特异性 ,又能保持立体分析的多元性。RCA亦是一种痕量的分子检测方法 ,可用于极其微量的生物大分子和生物标志的检测与研究     

Environmental distribution of trace fossils in the Jurassic of Kachchh (Western India)

Summary Trace fossils occur abundantly in Middle Jurassic rocks of the Kachchh Basin. They are found in environments ranging from beach sequences down to central parts of the basin. For stratinomic reasons, they are particularly well preserved in storm deposits. Their distribution pattern exhibits a clear relationship to the hydrodynamic conditions and, secondarily, to bathymetry, and follows the classic ichnofacies concept ofSeilacher (1967). High energy nearshore areas and submarine shoals are represented by members of the Skolithos ichnofacies such asOphiomorpha nodosa, Arenicolites, Diplocraterion parallelum, andRhizocorallium jenense. The storm-influenced ramp contains both members of the Cruziana ichnofacies (e.g.Rhizocorallium irregulare, Thalassinoides suevicus, Taenidium serpentinum, Chondrites) and the Skolithos ichnofacies (in particularOphiomorpha). The former were produced during interstorm phases, the latter are of post-storm origin. Carbonate ramp environments of low to intermediate energy also contain members of the Cruziana ichnofacies, whilst equivalent siliciclastic environments are characterized by a low-diversity Zoophycos ichnofacies. Low energy basinal environments of fine-grained substrates contain an impoverished Cruziana ichnofacies consisting ofChondrites, Trichichnus andThalassinoides suevicus. 32 ichnotaxa are briefly described, among themSphaerichnus lobatus ichnogen. et ichnosp. nov.     

La Grotte des Félins, site paléolithique du Pléistocène supérieur à Dar Bouazza (Maroc)

In the continental sediments filling a cave that developed in Middle Pleistocene deposits near Casablanca, Morocco, a very rich mammal fauna from the last climatic cycle was discovered. It was associated with a Middle Palaeolithic poor and atypical lithic assemblage manufactured on blocks and pebbles. The lower fossiliferous layer contained abundant carbonized remains of felids. Unfortunately, the site was destroyed by quarrying before adequate excavations could be carried out.     

Diagnostic potential of trace metals concentration in expressed prostatic secretion and serum of patients with category IV prostatitis

BackgroundThe National Institutes of Health (NIH) category IV prostatitis is a painless prostate gland inflammation, just as its name implies, this type of prostatitis is related with inflammation of the prostate, but most men are not conscious of it. However, category IV prostatitis is fairly common in general populations and reported having indirect relationships with prostate cancer.MethodWe analyzed the concentration of zinc (Zn), copper (Cu), calcium (Ca) and magnesium (Mg) in expressed prostatic secretion (EPS) and serum of patients with category IV prostatitis and healthy controls, investigating the diagnostic potential of different metals in category IV prostatitis using a flame atomic absorption spectrometer (FAAS).ResultsMetal concentration combined clinical characteristics analysis suggested that average level of Zn, Ca, Mg were significantly lower in the EPS of patients with category IV prostatitis (P-value< 0.000), while Cu level raised obviously (P-value< 0.000). And in the serum, mean concentrations of Ca was also found to increase significantly in the patients with category IV prostatitis compared to healthy controls. Moreover, the correlation analysis indicated that age showed a positive correlation with EPS Zn, Ca, Mg concentration (P-value< 0.05), while albumin correlates with EPS Zn, Ca, Mg concentration reversely (P-value< 0.05) in patients with category IV prostatitis.ConclusionOur report revealed that determination of the metal elements zinc, copper, calcium and magnesium in the serum and EPS could be a new and promising strategy for the rapid diagnosis of category IV prostatitis.     

Megarhizoliths in Pleistocene aeolian deposits from Gran Canaria (Spain): Ichnological and palaeoenvironmental significance

The Pleistocene dune field of Tufia, located on the east of Gran Canaria (Spain), contains different stratigraphic levels of indurated pillar-like structures that are interpreted as megarhizoliths. The megarhizoliths occur at the top of different aeolian sets and reach 31.5 cm in diameter and over 1 m in height. These scattered, free-standing, vertical, cylindrical-to-slightly conical columns usually appear as hollow cylinders, displaying elliptical cross-sections aligned with the prevailing wind. On the leeward side of some specimens the external wall shows a tail of rock matrix resembling a sort of “wind shadow”. These tails and other remains of the associated rock matrix show a texture composed of long, horizontal, parallel cylinders orientated with the wind.Internally the most complete structures show five concentrically arranged zones: Zone (a), is a central pore corresponding to the cavity originally occupied by the root; Zones (b) and (c), which include alveolar and laminated carbonate textures indicating that carbonate precipitation was mostly induced by the roots and their associated microorganisms; and Zones (d) and (e), consisting mostly of aeolian sands. In (d) the sand grains show thin micritic coatings whereas in (e) vadose aragonite cements can be seen on the grain surface suggesting a less biogenic influence in their formation. The degree of cementation and the time of the precipitation of carbonate around the roots controlled the preservation of these zones. Thus, in some cases, Zones b, c and/or d are not preserved. Cylinders are up to 30× the diameter of the root that nucleated them.The presence of the megarhizoliths at the top of the aeolianite beds indicates that aeolian sedimentation halted several times, allowing soil formation and plant colonisation during slightly more humid periods. The occurrence of megarhizoliths is further proof of the alternation of arid and slightly more humid climates in the north Atlantic during the last glacial period. It is also noted that they may be misinterpreted as animal trace fossils or tree trunk casts, resulting in incorrect ichnological or palaeoenvironmental interpretations.     

Ichnological analysis: The common ground between ichnofacies workers and ichnofabric analysts

This work compares the approaches taken by the two schools of applied ichnology (ichnofacies and ichnofabric analysts) and proposes an integrated approach for future improvement. There are many similarities between the two approaches, which mainly differ in the resolution at which ichnological analysis is undertaken. Ichnofabric work is by necessity performed on a bed-by-bed basis and interpreted at a scale consistent with that of the sedimentologist's facies. Ichnofacies studies, in contrast, seldom report bed-by-bed changes in ichnological content, instead highlighting bedset to facies association-scale changes in ichnology through comparison with summary models of ichnological trends.This work highlights the fact that workers from both schools utilize the same tools, with slightly different emphases, to reach their ichnological conclusions. Contention between the two schools has in recent years centred upon which is the better method for studying trace fossils—an artificial construct that detracts from the fact that both are extremely useful to sedimentological and palaeoenvironmental studies. Ichnofabric analysis is in addition, a highly effective means of documenting bioturbated sedimentary fabrics, as the basis for petrophysical studies. Ichnofacies and ichnofabric analysts use the same toolbox of ichnological methods to determine ancient palaeoenvironments—the scale of observation is generally different, but the results closely comparable. The recognition of key stratal surfaces on ichnological grounds is also possible with both methodologies. Ichnofacies analysts look to recognise Glossifungites ichnofacies firmgrounds in offshore mudstones. Ichnofabric studies would look to recognise overprinting of fabrics created by groups of organisms from different palaeoenvironments, but associated with the same key surface.It is proposed that the terms “ichnofacies method” and “ichnofabric analysis” are abandoned in favour of a neutral Ichnological Analysis Method, encompassing the approaches and terminology of both to produce a unified, scientifically rigorous, user-friendly methodology.     

Sedimentological evidence for rooting structures in the Early Devonian Anglo-Welsh Basin (UK), with speculation on their producers

Rooting structures preserved as casts in alluvial deposits of the Lower Devonian Lower Old Red Sandstone occur more extensively than previously thought in the Anglo-Welsh Basin. Two rooting structure morphotypes are identified: morphotype 1 being predominantly horizontal, and morphotype 2 comprising vertical forms. Both morphotypes taper along their length, are oval in cross-section, branch, and can be linear or sinuous. Fills are heterolithic in nature. The rooting structures are observed in sediments deposited in a wide variety of environments including both low-sinuosity within-channel bar-tops and accretionary bar surfaces (inclined-heterolithic stratification); accretionary banks of sinuous ephemeral channels (inclined-heterolithic stratification); floodplains (including margins of shallow floodplain ponds) of both ephemeral and perennial river channels, and well-developed calcic Vertisols. Although a vascular plant origin to the rooting structures cannot be discounted, there is circumstantial evidence that the structures were produced by the enigmatic Prototaxites, recently reinterpreted as a giant fungus. It is possible that they represent underground aggregates (rhizomorphs or cords) of hyphae involved in anchorage and nutrient foraging. Organic matter associated with biofilms and crusts is hypothesized as a source of nutrients for the presumed saprotroph.     

Serum trace element levels in HIV-infected subjects

The absolute number of T4 cells and the serum concentrations of Ca, Cu, Fe, K, Mg, P, Se, and Zn were determined in 59 Walter-Reed staged, HIV-infected men, compared to healthy controls, serum levels of Ca, Cu, and Fe were significantly higher, those of P and Se significantly lower in the HIV-infected subjects. In the HIV-infected cases, but not in the controls, the concentrations of Se and Zn, of Ca with Cu and Fe, and of Fe with P, were directly correlated. In the controls, the correlation between the levels of K and Mg was direct, and inverse between those of Zn and P. Trace element levels did not significantly correlate with WR-stage. However, the absolute number of T4 cells was directly correlated with the serum Mg concentration.     

山楂和山楂叶中25种元素的含量

本文报导了用电感耦合等离子体发射光谱法测定山楂和山楂叶中25种元素的含量,并讨论其中某些元素与山楂、山楂叶的药效之间的关系。