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81.
We attempted to mimic in small upflow anaerobic sludge bed (UASB) bioreactors the metabolic association found in nature between methanogens and methanotrophs. UASB bioreactors were inoculated with pure cultures of methanotrophs, and the bioreactors were operated by using continuous low-level oxygenation in order to favor growth and/or survival of methanotrophs. Unlike the reactors in other similar studies, the hybrid anaerobic-aerobic bioreactors which we used were operated synchronously, not sequentially. Here, emphasis was placed on monitoring various methanotrophic populations by using classical methods and also a PCR amplification assay based on the mmoX gene fragment of the soluble methane monooxygenase (sMMO). The following results were obtained: (i) under the conditions used, Methylosinus sporium appeared to survive better than Methylosinus trichosporium; (ii) the PCR method which we used could detect as few as about 2,000 sMMO gene-containing methanotrophs per g (wet weight) of granular sludge; (iii) inoculation of the bioreactors with pure cultures of methanotrophs contributed greatly to increases in the sMMO-containing population (although the sMMO-containing population decreased gradually with time, at the end of an experiment it was always at least 2 logs larger than the initial population before inoculation); (iv) in general, there was a good correlation between populations with the sMMO gene and populations that exhibited sMMO activity; and (v) inoculation with sMMO-positive cultures helped increase significantly the proportion of sMMO-positive methanotrophs in reactors, even after several weeks of operation under various regimes. At some point, anaerobic-aerobic bioreactors like those described here might be used for biodegradation of various chlorinated pollutants. 相似文献
82.
M LeBeau W Andollo WL Hearn R Baselt E Cone B Finkle D Fraser A Jenkins J Mayer A Negrusz A Poklis HC Walls L Raymon M Robertson J Saady 《Canadian Metallurgical Quarterly》1999,44(1):227-230
The recent increase in reports of drug-facilitated sexual assaults has caused alarm in the general public and prompted forensic toxicologists from across North America to address the toxicological issues surrounding this matter. The authors have developed recommendations and guidelines to inform law enforcement, medical, and scientific personnel of the requirements for performing successful toxicological examinations in cases of drug-facilitated rape. 相似文献
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85.
The past decade has seen a substantial increase in the number of individuals affected by dementia. Dementia places a tremendous personal and economic burden on millions of patients and caregivers annually. Consequently, many scientists have been searching for a treatment for dementia to avoid the imminent public health crisis that will occur if this trend continues. Primary and secondary prevention studies, as well as animal research, demonstrate the potential for hormone replacement therapy (HRT) as an efficacious treatment for dementia. Recently, the Women's Health Initiative-Memory Study began the first randomized, longterm clinical trial to test the hypothesized role of HRT at the onset and in the progression of dementia in women. Researchers also are investigating the potential of other treatments for dementias, such as nonsteroidal anti-inflammatory drugs and free radical scavengers. 相似文献
86.
Courts routinely award coverage for TMJ disorders under medical plans, despite exclusionary language and evidence that the insured failed to disclose preexisting treatment as required by the plan and neglected to attempt more conservative treatment first. Such decisions adversely affect both the health carrier and the plan participants. Various states have enacted legislation mandating coverage of TMJ; however, TMJ issues still exist and will remain a frequent topic for litigation until the judiciary recognizes that validating contract language ultimately benefits insureds as consumers and reinforces the integrity of the industry as a whole. 相似文献
87.
Chi Shiung Hsi Boen Houng Bing Yi Hou Guo Ju Chen Shen Li Fu 《Journal of Alloys and Compounds》2008,464(1-2):89-94
The addition of ruthenium in aluminum-doped zinc oxide transparent conducting thin films was deposited on polyethylene terephthalate at 20 °C by radio frequency magnetron sputtering technique. The structure and electrical properties of the films were investigated with respect to variation of Ru concentration. The XRD and FESEM results show that the film with 0.5 wt% Ru doping has the best crystallinity and larger pyramid-like grains, therefore the resistivity reached to a lowest value of 9.1 × 10−4 Ωcm. The low carrier mobilities of the films (3–7.2 cm2 V−1 s−1), however, were limited by ionized impurity scattering and grain boundary scattering mechanisms since the carrier concentrations were ranged from 2.2 × 1020 to 9.5 × 1020 cm−3. The transmittance in the visible is greater than 80% with the optical band gap in the order of 3.352–3.391 eV. 相似文献
88.
L Hacein-Bey ES Connolly SA Mayer WL Young J Pile-Spellman RA Solomon 《Canadian Metallurgical Quarterly》1998,43(6):1304-12; discussion 1312-3
OBJECTIVE: Endovascular management of complex intracranial aneurysms is increasingly being considered as an alternative to standard surgical clipping. However, little attention has been paid to the complementary nature of surgery and endovascular therapy. METHODS: Between September 1992 and May 1997, 12 patients with complex intracranial aneurysms were treated with combined operative and endovascular methods. Seven patients demonstrated subarachnoid hemorrhage (two of Grade II, two of Grade III, and three of Grade IV). Five patients demonstrated unruptured aneurysms, i.e., three giant aneurysms (one vertebrobasilar junction aneurysm, one middle cerebral artery bifurcation aneurysm, and one internal carotid artery-ophthalmic artery aneurysm), one large internal carotid artery-ophthalmic artery aneurysm, and one middle cerebral artery serpentine aneurysm. Management strategies involved either surgery followed by endovascular therapy (S-E; n = 5) or endovascular therapy followed by surgery (E-S; n = 7). S-E paradigms included aneurysm exploration followed by endovascular treatment (S-E1; n = 3), partial aneurysm clipping followed by endovascular aneurysm packing (S-E2; n = 1), and extracranial-to-intracranial bypass followed by endovascular parent vessel occlusion (S-E3; n = 1). E-S paradigms included superselective angiography followed by surgical clipping (E-S1; n = 2), Guglielmi detachable coil partial dome packing followed by delayed surgical clipping (E-S2; n = 2), proximal temporary vessel balloon occlusion followed by aneurysm clipping (E-S3; n = 2), and proximal permanent vessel occlusion followed by surgical aneurysm decompression for mass effect treatment (E-S4; n = 1). RESULTS: Eleven aneurysms (92%) were completely eliminated. The remaining aneurysm was 90% obliterated and remained quiescent at the 34-month follow-up examination, despite presenting with subarachnoid hemorrhage. No patient experienced repeat bleeding (follow-up period, 23+/-28 mo). There were no deaths. One patient achieved a fair outcome (Glasgow Outcome Scale score of III); all other patients experienced excellent outcomes (Glasgow Outcome Scale score of I). In all cases, the aneurysm management paradigm chosen had a positive effect on definitive therapy. CONCLUSION: Several factors can contribute to the complexity of intracranial aneurysms. Management strategies that combine operative and endovascular techniques in a complementary way, for the best possible outcomes for these patients, can be designed accordingly. 相似文献
89.
90.
Tumor-related prognostic factors for breast cancer 总被引:1,自引:0,他引:1
WL Donegan 《Canadian Metallurgical Quarterly》1997,47(1):28-51
Interest in prognostic factors for breast cancer has been stimulated by the success of systemic adjuvant therapy for early-stage operable disease. Patients destined for recurrence can be selected for systemic adjuvant therapy, while patients not likely to recur can be spared the morbidity of unnecessary treatment. The number of tumor-related features available for prognosis has grown impressively in recent years. The purpose of this article is to review tumor-related biologic factors and relate them to prognosis and treatment objectives. 相似文献