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1.
PETROLEUM POTENTIAL, THERMAL MATURITY AND THE OIL WINDOW OF OIL SHALES AND COALS IN CENOZOIC RIFT BASINS, CENTRAL AND NORTHERN THAILAND 总被引:1,自引:0,他引:1
Oil shales and coals occur in Cenozoic rift basins in central and northern Thailand. Thermally immature outcrops of these rocks may constitute analogues for source rocks which have generated oil in several of these rift basins. A total of 56 oil shale and coal samples were collected from eight different basins and analysed in detail in this study. The samples were analysed for their content of total organic carbon (TOC) and elemental composition. Source rock quality was determined by Rock‐Eval pyrolysis. Reflected light microscopy was used to analyse the organic matter (maceral) composition of the rocks, and the thermal maturity was determined by vitrinite reflectance (VR) measurements. In addition to the 56 samples, VR measurements were carried out in three wells from two oil‐producing basins and VR gradients were constructed. Rock‐Eval screening data from one of the wells is also presented. The oil shales were deposited in freshwater (to brackish) lakes with a high preservation potential (TOC contents up to 44.18 wt%). They contain abundant lamalginite and principally algal‐derived fluorescing amorphous organic matter followed by liptodetrinite and telalginite (Botryococcus‐type). Huminite may be present in subordinate amounts. The coals are completely dominated by huminite and were formed in freshwater mires. VR values from 0.38 to 0.47%Ro show that the exposed coals are thermally immature. VR values from the associated oil shales are suppressed by 0.11 to 0.28%Ro. The oil shales have H/C ratios >1.43, and Hydrogen Index (HI) values are generally >400 mg HC/g TOC and may reach 704 mg HC/ gTOC. In general, the coals have H/C ratios between about 0.80 and 0.90, and the HI values vary considerably from approximately 50 to 300 mg HC/gTOC. The HImax of the coals, which represent the true source rock potential, range from ~160 to 310 mg HC/g TOC indicating a potential for oil/gas and oil generation. The steep VR curves from the oil‐producing basins reflect high geothermal gradients of ~62°C/km and ~92°C/km. The depth to the top oil window for the oil shales at a VR of ~0.70%Ro is determined to be between ~1100 m and 1800 m depending on the geothermal gradient. The kerogen composition of the oil shales and the high geothermal gradients result in narrow oil windows, possibly spanning only ~300 to 400 m in the warmest basins. The effective oil window of the coals is estimated to start from ~0.82 to 0.98%Ro and burial depths of ~1300 to 1400 m (~92°C/km) and ~2100 to 2300 m (~62°C/km) are necessary for efficient oil expulsion to occur. 相似文献
2.
S Ziebe B Bech K Petersen AL Mikkelsen A Gabrielsen AN Andersen 《Canadian Metallurgical Quarterly》1998,13(1):178-181
A new oxidative pathway for the degradation of caffeine(1,3,7-Trimethylxanthine, I) by a mixed culture consisting of strains belonging to the genera Klebsiella and Rhodococcus is presented. The mixed culture does not initiate degradation by N-demethylation either complete or partial, but instead carries out oxidation at the C-8 position resulting in the formation of 1,3,7-trimethyluric acid (TMU, II) which further gets degraded to 3,6,8-trimethylallantoin (TMA, III). Both TMU and TMA are hitherto not shown to be formed in the microbial system. Further degradation of TMA (III) by caffeine grown cells yields dimethylurea (VII) as one of the metabolites. Oxygen uptake studies indicated that caffeine(I) grown cells oxidized TMU(II), TMA (III), glyoxalic acid (VI), dimethylurea(VII), and monomethylurea(V), but not monomethyl and dimethyluric acids. The mixed culture does not accept theophylline(1,3-dimethylxanthine), theobromine(3,7-dimethylxanthine), and paraxanthine(1,7-dimethylxanthine) as the carbon source. 相似文献
3.
JP Larsen H Odegaard E Tandberg A H?dneb? D Aarsland 《Canadian Metallurgical Quarterly》1996,9(4):157-163
As hypersensitivity to natural rubber latex (NRL) has become an increasingly recognized problem in children, identification of all groups at risk seems important. In this study hypersensitivity to NRL was evaluated in 337 children with potential risk factors. We identified by questionnaire children's underlying diseases, history of surgical procedures, evidence of atopy and patient's history of NRL-specific reactions. Hypersensitivity to NRL and other allergens relevant in the Düsseldorf area was evaluated by skin prick test and specific IgE. In 9.2% of all children hypersensitivity to NRL was observed. Significant risk factors for hypersensitivity to NRL were, among the underlying diseases, spina bifida (odds ratio 29.2), hydrocephalus internus (10.1), gastrointestinal malformation (5.2) and atopy (2.2). Surgical procedures with significant risk were the implantation of a ventriculo-peritoneal shunt (15.7) and surgery of the gastrointestinal tract (3.1). Frequency of surgical procedures correlated (p < 0.001) with risk of hypersensitivity. Frequent surgery and atopy were found to have an additional effect on the risk of hypersensitivity. Information about previous NRL-specific reactions obtained by questionnaire was of little predictive value when performing multivariate analysis. For children at high risk for hypersensitivity to NRL preoperative evaluation and, in case of hypersensitivity, preventive measures seem to be advised. 相似文献
4.
JA van Dorst CJ van Heusden JM Tikkanen JP Kamerling JF Vliegenthart 《Canadian Metallurgical Quarterly》1997,297(3):209-227
Seven analogues of the trisaccharide beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-->O)(CH 2)7CH3 have been synthesized as potential substrates for glycosyltransferases involved in the chain-termination of N-acetyllactosamine-type N-glycans. These compounds include: 3-O-methyl-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp -(1-->O) (CH2)7CH3, 3-deoxy-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1 -->O) (CH2)7CH3, 3-deoxy-3-fluoro-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-M anp- (1-->O)(CH2)7Ch3, 3-amino-3-deoxy-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Ma np- (1-->O)(CH2)7CH3, beta-D-Gulp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-- >O)(CH2)7CH3, beta-L-Galp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1-->O)(CH 2)7CH3, and alpha-L-Altp-(1-->4)-beta-D-GlcpNAc-(1-->2)-alpha-D-Manp-(1- ->O) (CH2)7CH3. All trisaccharides were obtained by condensation of suitably modified glycosyl donors based on imidates or thioglycosides with the same disaccharide acceptor, octyl 3,4,6-tri-O-benzyl-2-O-(3,6-di-O-benzyl-2-deoxy-2-phthalimido-beta-D- glucopyranosyl)-alpha-D-mannopyranoside, followed by deprotection. 相似文献
5.
The in vitro drug sensitivity of three dihydrofolate reductase inhibitors (pyrimethamine, cycloguanil, trimethoprim) was determined against 29 strains and isolates of Plasmodium falciparum by an isotopic semi-microtest. Trimethoprim is less active than pyrimethamine or cycloguanil and its activity is correlated with that of two other inhibitors, suggesting cross-resistance in vitro among the dihydrofolate reductase inhibitors. 相似文献
6.
P de Lonlay JC Fournet J Rahier MS Gross-Morand F Poggi-Travert V Foussier JP Bonnefont MC Brusset F Brunelle JJ Robert C Nihoul-Fékété JM Saudubray C Junien 《Canadian Metallurgical Quarterly》1997,100(4):802-807
Sporadic persistent hyperinsulinemic hypoglycemia of infancy (PHHI) or nesidioblastosis is a heterogeneous disorder characterized by profound hypoglycemia due to inappropriate hypersecretion of insulin. An important diagnostic goal is to distinguish patients with a focal hyperplasia of islet cells of the pancreas (FoPHHI) from those with a diffuse abnormality of islets (DiPHHI) because management strategies differ significantly. 16 infants with sporadic PHHI resistant to diazoxide and who underwent pancreatectomy were investigated. Selective pancreatic venous sampling coupled with peroperative surgical examination and analysis of extemporaneous frozen sections allowed us to identify 10 cases with FoPHHI and 6 cases with DiPHHI. We show here that in cases of FoPHHI, but not those of DiPHHI, there was specific loss of maternal alleles of the imprinted chromosome region 11p15 in cells of the hyperplastic area of the pancreas but not in normal pancreatic cells. This somatic event is consistent with a proliferative monoclonal lesion. It involves disruption of the balance between monoallelic expression of several maternally and paternally expressed genes. Thus, we provide the first molecular explanation of the heterogeneity of sporadic forms of PHHI such that it is possible to perform only partial pancreatectomy, limited to the focal somatic lesion, so as to avoid iatrogenic diabetes in patients with focal adenomatous hyperplasia. 相似文献
7.
F Koumanov C Henry C Ghezzi JP Mathieu C Morin M Vidal J de Leiris M Comet D Fagret 《Canadian Metallurgical Quarterly》1997,24(6):519-525
Two anomeric analogues of glucose labelled with 123 iodine in position 6, proposed as tracers of glucose transport in vivo, have been synthesized: alpha- and beta-methyl-6-deoxy-6-iodo-D-glucopyranoside (alpha MDIG and beta MDIG). The aim of this study was to determine whether these molecules interact with the glucose transporter and whether they could be used as tracers of glucose transport in vivo. The biodistribution of alpha MDIG and beta MDIG was studied in the mouse in vivo. To determine if these two anomers enter the cell via the glucose transporter, their uptake was measured in isolated perfused rat hearts, in human erythrocytes in suspension, and in cardiomyocytes of neonatal rat in culture. Both alpha MDIG and beta MDIG had similar repartitions in the mouse: myocardial uptake averaged 7% of the injected dose/g of organ at 2 min postinjection and alpha MDIG competed with D-glucose to enter the cells. Insulin produced a 123% increase of its uptake in isolated perfused rat hearts and a 100% increase in cardiomyocytes of neonatal rat in culture. alpha MDIG uptake was lowered in the presence of glucose transport inhibitors in each experimental model. An interaction between beta MDIG and glucose transporters was observed only in human erythrocytes in suspension. Only alpha MDIG interacts with the glucose transporter, and thus could be used to estimate glucose transport in vivo. 相似文献
8.
Assuming that the chemical reactions used to synthesize a combinatorial library member are successful, then knowledge of the specific reaction sequence is equivalent to knowing the member's chemical identity. Because the determination of chemical identity is typically not automatable and requires a substantial amount of material, schemes that encode a member's reaction history onto the reaction platform are of value. The primary benefits of encoding are relational nomenclature (all methods) and automated handling (some methods). Encoding methods evaluated to date are spatial, graphical, chemical, spectrometric, electronic, and physical. 相似文献
9.
JA Calera S Paris M Monod AJ Hamilton JP Debeaupuis M Diaquin R López-Medrano F Leal JP Latgé 《Canadian Metallurgical Quarterly》1997,65(11):4718-4724
Aspergillus fumigatus possesses two catalases (described as fast and slow on the basis of their electrophoretic mobility). The slow catalase has been recognized as a diagnostic antigen for aspergillosis in immunocompetent patients. The antigenic catalase has been purified. The enzyme is a tetrameric protein composed of 90-kDa subunits. The corresponding cat1 gene was cloned, and sequencing data show that the cat1 gene codes for a 728-amino-acid polypeptide. A recombinant protein expressed in Pichia pastoris is enzymatically active and has biochemical and antigenic properties that are similar to those of the wild-type catalase. Molecular experiments reveal that CAT1 contains a signal peptide and a propeptide of 15 and 12 amino acid residues, respectively. cat1-disrupted mutants that were unable to produce the slow catalase were as sensitive to H2O2 and polymorphonuclear cells as the wild-type strain. In addition, there was no difference in pathogenicity between the cat1 mutant and its parental cat1+ strain in a murine model of aspergillosis. 相似文献
10.
F Douaud N Le Roch J Renault R Havouis M Vaultier JP Moulinoux N Seiler 《Canadian Metallurgical Quarterly》1997,12(8):621-633
Several dimethylsilane tetramines [homologs of spermine with an Si(CH3)2 group in the central carbon chain], a carbon analog of the dimethylsilane tetramines [containing C(CH3)2 instead of Si(CH3)2] and a dimethylsilane hexamine were studied with regard to their cytotoxic activity and their ability to interact with double-stranded DNA. All polyamine analogs exerted cytostatic effects to several cell lines at micromolar concentrations. Their ability to condense DNA was comparable to and their ability to displace ethidium bromide from binding to DNA was superior to that of spermine. Their cytostatic effect was not correlated with the depletion of cellular spermidine concentrations. It is suggested that the new polyamine analogs act mainly by displacing spermidine from binding sites which are essential for the promotion of cell growth. 相似文献