随时间推移（TL）地震勘探处理方法研究

随时间推移（TL）地震勘探已经在油田开发领域见到了一些成功的实 ,关于TL地震勘探的可行性论证也有不少文章讨论过,但是对于陆上薄互层（储层厚度小于10m),大地吸收较强,信噪比较低和严重空变激发,接收因素影响条件下的TL地震可行性论证和数据处理还存在一些问题需要解决,本文从实际地震数据问题（如50Hz工业干扰,地层吸收,激光能量和频率空变,近地表鸣震干扰和接收器影响等问题）分析入手,发现这些问题难以用常规处理和互均衡处理方法来解决,为此,本文针对以上问题提出了特殊的处理方法和流程,较好地消除了这些干扰影响,并在不采用互均衡处理条件下获得TL地震储层的差异信息。     

The effects of incorporated tritium and bromodeoxyuridine on the frequency of sister chromatid exchanges

Cells in third mitosis treated during the first cell cycle with 3H-TdR and during the next two cycles with BrdU (without 3H-TdR) show a typical pattern of chromosome differentiation which allows identification of sister chromatid exchanges occurring during the first (SCE1), second (SCE2) and third cycles (SCE3). Chromosomes labeled only with 3H-TdR had the most SCEs; those labeled only with BrdU, the second highest number; and those labeled with 3H-TdR plus BrdU, the fewest. Since BrdU and 3H-TdR are well known inducers of SCEs, the relatively low frequency of exchanges produced by the combined action of these two compounds is paradoxical. It is assumed that SCEs are generated by the abnormal recombination of double-strand DNA breaks occurring at the junctions between completely and partially duplicated replicon clusters. Thus, agents that induce absolute blocks to DNA fork displacement will favor the appearance of SCEs because double-strand breaks have more time to occur at junctions. Conversely, agents that inhibit the initiation of replication will decrease the probability of SCEs. Ionizing radiation delays the onset of cluster replication. Therefore, in 3H-TdR plus BrdU-substituted chromosomes the radiation from tritium may inhibit the appearance of BrdU-induced SCEs. Since the inhibition does not exist in chromosomes substituted only with BrdU, the frequency of SCEs in these elements is higher than in double-substituted chromosomes. During the first cell cycle the onset of cluster replication is normal. However, the incorporation of 3H-TdR in the replication fork may enhance the appearance of double-strand breaks, thus inducing a high frequency of SCEs.     

Characterization of mitochondrial DNA and Y-chromosome haplotypes in a Uruguayan population of African ancestry

We used a set of informative mtDNA and Y-chromosome-specific markers to determine the origin of maternal and paternal lineages in a sample of 41 Uruguayan black individuals. We found that 20 maternal lineages were African, 13 were Amerindian, and 5 were Caucasian. In three individuals we were unable to determine the ethnic origin of the mtDNA lineages. Of the 22 males analyzed we found 4 Y chromosomes of African origin, 5 of Caucasian origin, and 13 of undetermined ancestry. Our results suggest that mtDNA and Y-chromosome-specific DNA variants may be a useful tool in determining the level of mtDNA and Y chromosome ethnic introgression in a population of a given ethnic origin.     

蒸发器焊缝开裂的原因分析

系统分析蒸发器焊缝大面积开裂的原因 ,确定应力腐蚀—碱脆是焊缝开裂的主要原因 ,焊接残余应力是引起焊缝开裂的主要应力 ,并提出相应的防护措施     

Quantitative analysis of carcinoembryonic antigen messenger RNA in peripheral venous blood and portal blood of patients with pancreatic ductal adenocarcinoma

OBJECTIVES: We sought to investigate the long-term efficacy of slow-pathway catheter ablation in patients with spontaneous, documented paroxysmal supraventricular tachycardia (PSVT) and dual atrioventricular (AV) node pathways but without inducible tachycardia. BACKGROUND: The lack of reproduction of clinical PSVT by programmed electrical stimulation, which is not uncommon in AV node reentrant tachycardia (AVNRT), is a dilemma in making the decision of the therapeutic end point of radiofrequency catheter ablation. METHODS: Twenty-seven patients (group A) with documented but noninducible PSVT and with dual AV node pathways were prospectively studied. Programmed electrical stimulation could induce a single AV node echo beat in 12 patients, double echo beats in 4 patients and none in 11 patients at baseline or during isoproterenol infusion. Of the patients in group A, 16 underwent slow-pathway catheter ablation and 11 did not. The clinical and electrophysiologic characteristics of the 27 patients were compared with those of patients with dual AV node pathways and inducible AVNRT (group B, n = 55) and patients with dual AV node pathways alone without clinical PSVT (group C, n = 47). RESULTS: During 23+/-13 months of follow-up, none of the 16 patients with slow-pathway catheter ablation had recurrence of PSVT. However, 7 of the 11 patients without ablation had PSVT recurrence at 13+/-14 months of follow-up (p < 0.03 by Kaplan-Meier analysis). Compared with groups B and C, group A consisted predominantly of men who had better retrograde AV node conduction and a narrower zone for anterograde slow-pathway conduction. CONCLUSIONS: Slow-pathway catheter ablation is highly effective in eliminating spontaneous PSVT in which the tachycardia is not inducible despite the presence of dual AV node pathways.     

Phospholipase A2-mediated activation of mitogen-activated protein kinase by angiotensin II

In renal proximal tubule epithelial cells, a membrane-associated phospholipase A2 (PLA2) is a major signaling pathway linked to angiotensin II (Ang II) type 2 receptor (AT2). The current studies were designed to test the hypothesis that membrane-associated PLA2-induced release of arachidonic acid (AA) and/or its metabolites may serve as an upstream mediator of Ang II-induced mitogen-activated protein kinase (MAPK) activation. Ang II stimulated transient dose-dependent phosphorylation of MAPK with a maximum at 1 microM (10 min). Inhibition of PLA2 by mepacrine diminished both AA release and MAPK phosphorylation, induced by Ang II. Furthermore, AA itself induced time- and dose-dependent phosphorylation of MAPK, supporting the importance of PLA2 as a mediator of Ang II signaling. The effects of both Ang II and AA on MAPK phosphorylation were protein kinase C independent and abolished by the inhibitor of cytochrome P450 isoenzyme, ketoconazole. Moreover, 5,6-epoxyeicosatrienoic acid and 14,15-epoxyeicosatrienoic acid, the cytochrome P450-dependent metabolites of AA, significantly stimulated MAPK activity in renal proximal tubule epithelial cells. These observations document a mechanism of Ang II-induced MAPK phosphorylation, mediated by PLA2-dependent release of AA and cytochrome P450-dependent production of epoxy derivatives of AA.     

Rapid brain autopsy. The Joseph and Kathleen Bryan Alzheimer's Disease Research Center experience

OBJECTIVE: To develop a system for retrieving brain tissue within 1 hour after death in an effective and useful manner. DESIGN: Nurse clinicians were employed as study co-ordinators and were available to families 24 hours each day. SETTING: Autopsies were performed at Duke University Medical Center, Durham, NC, from 1985 through 1995. PARTICIPANTS: Neuropathology faculty, fellows, and residents, autopsy technicians; and brain bank staff. RESULTS: Fifty-one rapid autopsies with a postmortem interval of less than 1 hour have been performed. Four of these were normal controls, three were disease controls, and 44 represented Alzheimer's disease patients. Tissue retrieved at rapid autopsy has been distributed to 93 research teams, 30 of these located at Duke University Medical Center. Many researchers have received multiple shipments of tissue. CONCLUSIONS: The Bryan Alzheimer's Disease Research Center Rapid Autopsy Program at Duke University Medical Center has been successful in retrieving tissue from individuals with dementia and also from controls within 1 hour of death. The critical features of the success of this program have been the use of nurse clinicians who work closely with patients and their families to ensure a successful autopsy at the time of death and the maintenance of a 24-hour call schedule for nurses and neuropathology staff. Similar programs can be implemented for experimental work into the pathogenesis of a wide variety of human diseases in which the examination of human tissue is required.     

Northern bobwhites as disease indicators for the endangered Attwater''s prairie chicken

Gabapentin is an anticonvulsant that may represent a novel class of drugs, which has novel spinal antihyperalgesic activity. We sought to characterize this spinal action in a model of hyperalgesia that involves a mild thermal injury to the hind paw of the rat. Rats were prepared with chronic spinal catheters. Under brief halothane anesthesia, a thermal injury was induced by applying the left hind paw to a thermal surface (52.5 degrees C) for 45 s. This exposure results in mild erythema but no blistering. Thermal escape latency of the hind paw was determined using an underglass thermal stimulus with which response latencies of the injured and uninjured (normal) paw could be obtained. Thirty minutes after thermal injury, the response latency in all groups decreased from 10-12 s to 5-7 s. Uninjured paw withdrawal latency was unaltered. The intrathecal injection of gabapentin (30-300 microg) produced a dose-dependent reversal of the hyperalgesia but had no effect on the response latency of the normal hind paw, even at the largest doses. A similar reversal was observed after intrathecal delivery of the structural analog S(+)-3-isobutyl gamma-aminobutyric acid (GABA) (30-300 microg), but not after the largest dose of its stereoisomer R(-)-3-isobutyl GABA (300 microg). The effects of both intrathecal gabapentin and S(+)-3-isobutyl GABA were reversed by intrathecal D-serine, but not L-serine. All effects were observed at doses that had no significant effect on motor function. These observations, in conjunction with the accumulating data on binding and transmitter release, emphasize that these gabapentinoids can selectively modulate the facilitation of spinal nociceptive processing otherwise generated by persistent small afferent input generated by tissue injury. Implications: Gabapentin and its analog, 3-isobutyl gamma-aminobutyric acid, given spinally, produce a dose-dependent, D-serine-sensitive reversal of the thermal hyperalgesia evoked by mild thermal injury.     

Sodium fusidate and the cytokine response in an experimental model of acute pancreatitis

Previously, we described cloning of three alternatively spliced mRNA forms of human FGF8, a, b, and e, of which the b form is the major expressed species in both normal and tumor prostatic epithelial cells. In this report, we describe construction and overexpression of sense and antisense sequences of either the full length FGF8b coding region (215-amino acids or 215aa), 103aa N-terminal part or a smaller N-terminal region (34aa), each including the 23aa putative signal peptide domain, via a retrovirus system. While the morphologic transforming activities of the sense 215aa and 103aa constructs were similar in NIH3T3 cells, 103aa displayed reduced soft agar clonogenic activity. The 34aa construct was practically inert in these assays, although its expression could mimic the ability of 215aa or 103aa in conferring cell growth under reduced serum condition. Overexpression of any of the three constructs in antisense orientation, however, was similarly effective in reversing the morphology and anchorage-independent growth property of FGF8b-transfected NIH3T3 cells. The expression of the antisense 215aa construct significantly reduced the growth rate of the human prostatic carcinoma DU145 cells and inhibited their soft agar clonogenic activity and in vivo tumorigenicity in nude mice. Taken together, these results identify N-terminal portions of FGF8 protein isoform for having the domains necessary for one or more of the biologic effects examined, and suggest that low levels of FGF8 expressed in prostatic epithelial cells may contribute significantly to their growth and tumorigenic properties.     

基于CAN总线技术的车辆虚拟仪表数据采集系统的设计

介绍了基于CAN总线的车辆虚拟仪表多路数据采集系统的设计方法，给出了系统详细框图和关键电路图，详细分析了CAN通信子程序，并给出了CAN通信初始化子程序、数据发送和中断服务程序流程图。