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971.
Alcaligenes faecalis G utilized 95–97% of 5–15 g -caprolactam l–1 in 24–48 h over a pH range of 6–8.5 and at 23–40 °C, without complex nutrient requirement. In the absence of KH2PO4 and K2HPO4/MgSO4 in the medium, only 7.6% and 0.2% of 10 g caprolactam l–1 was utilized, respectively. The chemical oxygen demand (COD) of the wastewater of nylon-6 plant was mainly due to its caprolactam content. A. faecalis G decreased the caprolactam content and COD of the wastewater by 80–90% of the original in spite of the wastewater having higher caprolactam content (3600 mg l–1) and COD (7700 mg l–1) than those of any of the previous reports. 相似文献
972.
973.
B Zanella N Calonghi E Pagnotta L Masotti C Guarnieri 《Biochemical and biophysical research communications》2002,290(3):1010-1014
This study shows the presence of all three nitric oxide synthases (NOSs) and NOS activity in H9c2 cells cultured under non-stimulated conditions. By using the 4,5 diaminofluoresceindiacetate (DAF-2DA) fluorimetric nitric oxide (NO(*)) detection system we observed NO(*) production in H9c2 cells. As revealed by confocal microscopy, NO(*) fluorescence colocalizes in mitochondria labeled with Mito-Tracker Red CM-H(2)Xros. Upon stimulation with acetylcholine (Ach), which increased NOS activity by 75%, the colocalization coefficient C(green) value, calculated as Pearson's correlation, increased from 0.07 to 0.10, demonstrating an augmented presence of NO(*) in mitochondria. Conversely, the presence of NO(*) in mitochondria decreased following cells pretreatment with l-MonoMethylArginine (L-NMMA), a competitive inhibitor of NOS activity, as indicated by the reduction of the C(green) value to 0.02. This work confirms that the presence of NO(*) in mitochondria can be modulated in response to different fluxes of NO(*). 相似文献
974.
Sources of nitrate in rivers draining sixteen watersheds in the northeastern U.S.: Isotopic constraints 总被引:3,自引:4,他引:3
Mayer Bernhard Boyer Elizabeth W. Goodale Christine Jaworski Norbert A. van Breemen Nico Howarth Robert W. Seitzinger Sybil Billen Gilles Lajtha Kate Nadelhoffer Knute Van Dam Douwe Hetling Leo J. Nosal Miloslav Paustian Keith 《Biogeochemistry》2002,(1):171-197
The feasibility of using nitrogen and oxygenisotope ratios of nitrate (NO3
–) forelucidating sources and transformations ofriverine nitrate was evaluated in a comparativestudy of 16 watersheds in the northeastern U.S.A. Stream water was sampled repeatedly at theoutlets of the watersheds between January andDecember 1999 for determining concentrations,15N values, and 18Ovalues of riverine nitrate.In conjunction with information about land useand nitrogen fluxes,15Nnitrate and18Onitrate values providedmainly information about sources of riverinenitrate. In predominantly forested watersheds,riverine nitrate had mean concentrations ofless than 0.4 mg NO3
–-N L–1,15Nnitrate values of lessthan +5, and 18Onitratevalues between +12 and +19. This indicatesthat riverine nitrate was almost exclusivelyderived from soil nitrification processes withpotentially minor nitrate contributions fromatmospheric deposition in some catchments. Inwatersheds with significant agricultural andurban land use, concentrations of riverinenitrate were as high as 2.6 mg NO3
–-NL–1 with 15Nnitratevalues between +5 and +8 and18Onitrate values generallybelow +15. Correlations between nitrateconcentrations, 15Nnitratevalues, and N fluxes suggest that nitrate inwaste water constituted a major, and nitrate inmanure a minor additional source of riverinenitrate. Atmospheric nitrate deposition ornitrate-containing fertilizers were not asignificant source of riverine nitrate inwatersheds with significant agricultural andurban land use. Although complementary studiesindicate that in-stream denitrification wassignificant in all rivers, the isotopiccomposition of riverine nitrate sampled at theoutlet of the 16 watersheds did not provideevidence for denitrification in the form ofelevated 15Nnitrate and18Onitrate values. Relativelylow isotopic enrichment factors for nitrogenand oxygen during in-stream denitrification andcontinuous admixture of nitrate from theabove-described sources are thought to beresponsible for this finding. 相似文献
975.
Roberta Pini 《Vegetation History and Archaeobotany》2002,11(4):251-262
The local and regional history of vegetation and climate, from the Late Glacial to the present, is represented in a new,
high-resolution pollen diagram from Pian di Gembro (1350 m asl), ten 14C dates providing a reliable time control. An open pioneer vegetation dominated by Artemisia, Gramineae, and and Chenopodiaceae followed the retreat of the glaciers after the Last Glacial Maximum. Shrub vegetation
with Juniperus, Alnus viridis, and Salix expanded soon after. Denser Betula-Pinus forests were present in Pian di Gembro around 12,320 B.P. Their extent was greatly reduced by the climatic cooling of the
Younger Dryas, when open vegetation spread again. The beginning of the Holocene was marked by a considerable expansion in
mixed oak taxa. Corylus immigrated to the site at 9,250 B.P. Picea and Abies expanded at 7,370 B.P., recording an abrupt change in the structure of the vegetational belts. A coeval climatic change is
evidenced in the GRIP records and also detectable through oscillations of the timberline. Signs of human impact are present
since late Atlantic, becoming more intense around 2,200 B.P. As pasture lands increased, Abies and Fagus slowly disappeared. The introduction of Castanea and Juglans is dated to Roman times, and Secale to the Middle Ages.
Received February 4, 2002 / Accepted August 2, 2002 相似文献
976.
Hideo Ikeda 《Molecular & general genetics : MGG》1986,202(3):518-520
Summary Illegitimate recombination dependent on T4 DNA topoisomerase in a cell-free system has recently been described. In that work, recombinants between two phage DNA molecules were produced by the topoisomerase alone, without an Escherichia coli extract. In this paper, it is shown that recombination between phage and circular plasmid DNA molecules can also be detected in the presence or absence of an E. coli extract but at frequencies two or three orders of magnitude lower than that observed in the phage-phage cross. The frequency is probably lower because multiple recombination is required in the case of the phage-plasmid cross. 相似文献
977.
Monika Primon Peter C. Huszthy Helena Motaln Krishna M. Talasila Ana Torkar Rolf Bjerkvig Tamara Lah Turnšek 《Experimental cell research》2013
Despite improved treatment options, glioblastoma multiforme (GBM) remains the most aggressive brain tumour with the shortest post-diagnostic survival. Arsenite (As2O3) is already being used in the treatment of acute promyelocytic leukaemia (APL), yet its effects on GBM have not been evaluated in detail. In U87MG cell monolayers, we have previously shown that arsenite cytotoxicity significantly increases upon transient inhibition of lysosomal protease Cathepsin L (CatL). As multicellular spheroids more closely represent in vivo tumours, we aimed to evaluate the impact of permanent CatL silencing on arsenite treatment in U87MG spheroids. CatL was stably silenced using shRNA expression plasmid packed lentiviruses. By using metabolic- and cell viability assays, we demonstrated that long-term CatL silencing significantly increased arsenite cytotoxicity in U87MG spheroids. Silenced CatL also increased arsenite-mediated apoptosis in spheroids via elevated p53 expression, Bax/Bcl2 ratio and caspase 3/7 activity, though with lower efficacy than in monolayers. Arsenite cytotoxicity was enhanced by lower CatL activity, since similar cytotoxicity increase was also observed using the novel CatL inhibitor AT094. The results have significant translational impact, since stable CatL silencing would enable the application of lower systemic doses of arsenite to achieve the desired cytotoxic effects on GBMs in vivo. 相似文献
978.
Ginger R. Zipperer Sridhar Arumugam Sharon R. Chirgwin Sharon U. Coleman Krishna P. Shakya Thomas R. Klei 《Experimental parasitology》2013
Previous studies have shown that intradermally (ID) injected Brugia pahangi L3s migrate through various tissues and into the lymphatics of gerbils in a distinct pattern. Excretory/secretory products (ES) produced at the time of invasion of B. pahangi are likely to be important in this early migration phase of the parasite life cycle in their rodent host. Hence, early L3 ES was collected from 24 h in vitro cultures of B. pahangi L3 larvae and used in immunization experiments to investigate the effect of immunity to early L3 ES on worm migration, survival and development of B. pahangi. Immunization of gerbils with ES in RIBI adjuvant produced antibodies to numerous ES proteins eliciting a strong humoral response to ES and indirect fluorescent antibody (IFA) assay using anti-ES serum recognized the ES proteins on the surface of B. pahangi L3 larvae. Following ES immunization, gerbils were challenged either ID or intraperitoneally (IP) with 100 L3s of B. pahangi and euthanized at 3 or 106 days post inoculation (DPI). Immunization with early ES slowed the migration of ID inoculated L3 at 3 DPI and significantly altered the locations of adult worms at 106 DPI. Immunization did not induce protection in any treatment group. However, immunized animals had significantly fewer microfilariae per female worm suggesting the antigens in ES are important in microfilariae development or survival in the host. The number of lymphatic granulomas was also significantly reduced in ES immunized animals. It is important to note that microfilariae serve as a nidus in these granulomas. Our results shows immunization with early Brugia malayi L3 ES alters the worm migration, affects circulating microfilarial numbers and reduces lymphatic granulomas associated with B. pahangi infection in gerbils. 相似文献
979.
Gerda Neubert Katja von Au Katrin Drossel Andreas Tzschach Denise Horn Renate Nickel Angela M. Kaindl 《Gene》2013
Angelman syndrome is a neurodevelopmental disorder characterized by mental retardation, severe speech disorder, facial dysmorphism, secondary microcephaly, ataxia, seizures, and abnormal behaviors such as easily provoked laughter. It is most frequently caused by a de novo maternal deletion of chromosome 15q11–q13 (about 70–90%), but can also be caused by paternal uniparental disomy of chromosome 15q11–q13 (3–7%), an imprinting defect (2–4%) or in mutations in the ubiquitin protein ligase E3A gene UBE3A mostly leading to frame shift mutation. In addition, for patients with overlapping clinical features (Angelman-like syndrome), mutations in methyl-CpG binding protein 2 gene MECP2 and cyclin-dependent kinase-like 5 gene CDKL5 as well as a microdeletion of 2q23.1 including the methyl-CpG binding domain protein 5 gene MBD5 have been described. Here, we describe a patient who carries a de novo 5 Mb-deletion of chromosome 15q11.2–q13.1 known to be associated with Angelman syndrome and a further, maternally inherited deletion 2q21.3 (~ 364 kb) of unknown significance. In addition to classic features of Angelman syndrome, she presented with severe infections in the first year of life, a symptom that has not been described in patients with Angelman syndrome. The 15q11.2–q13.1 deletion contains genes critical for Prader–Willi syndrome, the Angelman syndrome causing genes UBE3A and ATP10A/C, and several non-imprinted genes: GABRB3 and GABRA5 (both encoding subunits of GABA A receptor), GOLGA6L2, HERC2 and OCA2 (associated with oculocutaneous albinism II). The deletion 2q21.3 includes exons of the genes RAB3GAP1 (associated with Warburg Micro syndrome) and ZRANB3 (not disease-associated). Despite the normal phenotype of the mother, the relevance of the 2q21.3 microdeletion for the phenotype of the patient cannot be excluded, and further case reports will need to address this point. 相似文献
980.
Liangliang Sun Yanyan Zhang Dingyin Tao Guijie Zhu Qun Zhao Qi Wu Zhen Liang Ling Yang Lihua Zhang Yukui Zhang 《Proteomics》2012,12(23-24):3464-3469
Comprehensive identification of cytochrome P450 enzymes (CYPs) and uridine diphosphoglucuronosyl transferases (UGTs) in human liver microsomes (HLMs) was performed with an SDS‐PAGE‐free protocol. HLMs were solubilized with 5% v/v ionic liquid, 1‐butyl‐3‐methyl imidazolium tetrafluoroborate, followed by tryptic digestion, and 2D‐SCX‐RPLC‐ESI‐MS/MS (LTQ XL) analysis in triplicate. In total, 27 CYPs and 12 UGTs were confidently identified with average sequence coverage as 30.99 and 25.07%, average peptide number as 14 and 13, and average unique peptide number as 7 and 4, respectively. The highly similar isoforms of CYP3A, CYP2C, and CYP4F subfamilies could be unambiguously differentiated from each other, despite the fact that the sequence similarity of CYP2C9 and CYP2C19 is 91%. In addition, protein spectral count was used to approximately evaluate the relative abundance of identified CYPs and UGTs, and the results agreed with previous immunochemistry reports. 相似文献