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1.
Summary Raw and cured compost samples from a large-scale urban composter were studied over a period of eight months to gain information on bacterial species present. Total viable, aerobic heterotrophic bacteria, lactose-positive bacteria, antibiotic and metal-resistant bacteria and thermophilic bacteria were enumerated. Both raw and cured compost samples contained metal and antibiotic-tolerant bacteria (–1 compost) as well as high numbers (as high as Log 7.4 CFU g–1 dry weight compost) of thermophilic bacteria isolated by growth at 55 °C. Selected colonies were also identified using the Biolog 95 substrate identification system.Escherichia coli andSalmonella spp. were not detected in compost samples.  相似文献   

2.
Polymerase Chain Reaction, based on amplification of a fragment of Dth18 gene, was applied to detect and specifically to identify Listeria monocytogenes present in silages. About 15 CFU g–1 of fresh or fermented vegetables have been routinely detected using this rapid technique.  相似文献   

3.
About 650 zooplankton samples were collected from Lake Inarijärvi in 1977–1979 from the littoral and pelagial zones of the lake. One hundred and twenty-three zooplankton taxa were found and most of them can be considered euplanktonic.The most important species were Holopedium gibberum, Daphnia cristata, Cyclops spp. and Eudiaptomus spp. Mean pelagial zooplankton biomass was 0.29 g m–3 in the 0–5 m depth zone, 0.17 g m–3 in 5–10 m and 0.11 g m–3 in 10–20 m.The zooplankton biomass at a sandy shore was about 0.09 g m–3, at a stony shore 0.05 g m–3 and at a vegetated shore 0.76 g m–3. About 70% of the whole zooplankton production consisted of crustaceans.The sum of herbivore and carnivore zooplankton production in the pelagial area during the summer was 210–330 kg ha–1 × 3 months.  相似文献   

4.
Clinical samples obtained from 200 patients with intra-abdominal infections were investigated for the presence of anaerobic bacteria. The majority of samples were from patients with appendicitis (108, 54%) followed by peritoneal abscess/peritonitis (37, 18.5%). A total of 153 anaerobes were isolated from 83 culture positive specimens with an isolation rate of 1.8 per sample. Ninety (59%) yielded Bacteroides fragilis group and B. fragilis stricto sensu accounted for half of them. Other isolates were 36 (23.5%) Prevotella species and 15 (9.8%)Peptostreptococcus micros . The susceptibility of the 153 isolates against eight antibiotics was determined by the E-test. All the isolates were susceptible to metronidazole, MIC90s varying between 1–2 μg/mL. ThePrevotella spp., Peptostreptococcus spp., Fusobacterium spp. and Porphyromonas spp. were all susceptible to clindamycin (MIC90s=0.25–2 μg/mL respectively), imipenem (MIC90s=0.12–0.5μg/mL respectively) and meropenem (MIC90=0.25 μg/mL each). About 25% of the B. fragilis group were resistant to clindamycin with MIC more than 256 μg/mL. Piperacillin-tazobactam also exhibited excellent in vitro activity against all the isolates (MIC90=0.25 μg/mL).  相似文献   

5.
Both total and biological particles (totalculturable bacteria, Gram negative bacteria,mold and actinomycetes) were measured at ananimal feed manufacturing industry. Suspendedparticle concentration ranged from 1.72 to2.3 mg m–3 with a mean value of1.97 mg m–3. Airborne microorganisms weredetected in lower concentrations than thoseassociated with suspended dust andfeed-materials. Bacterial concentrations weretwo to three times higher than concentrationsof mold and actinomycetes. Bacterialconcentrations averaged4.86 × 103 cfu m–3; 2.6 × 104cfu m–3 and 3.96 × 107 cfu g–1 inair, associated with suspended dust andfeed-materials, respectively, whereas moldconcentrations averaged 7.33 × 102cfu m–3; 1.97 × 103 cfu m–3 and7 × 105 cfu g–1 of the correspondingenvironments, respectively. Enterobacterspp and Klebsiella spp were the mostabundant Gram negative bacteria, whereas Bacillus species. were the most dominant Grampositive bacteria. Aspergllius niger,other Aspergillus species and Penicillium were the dominant mold isolates.Acremonium was only detected in feedmaterials, whereas Aspergillus fumigatuswas only detected in air. The animal feedindustry environment has a significantbio-contamination and many of microorganismsimplicated in respiratory problems weredetected in this environment.  相似文献   

6.
The efficient conversion of xylose-containing biomass hydrolysate by the ethanologenic yeast Saccharomyces cerevisiae to useful chemicals such as ethanol still remains elusive, despite significant efforts in both strain and process development. This study focused on the recovery and characterization of xylose chemostat isolates of a S. cerevisiae strain that overexpresses xylose reductase- and xylitol dehydrogenase-encoding genes from Pichia stipitis and the gene encoding the endogenous xylulokinase. The isolates were recovered from aerobic chemostat cultivations on xylose as the sole or main carbon source. Under aerobic conditions, on minimal medium with 30 g l–1 xylose, the growth rate of the chemostat isolates was 3-fold higher than that of the original strain (0.15 h–1 vs 0.05 h–1). In a detailed characterization comparing the metabolism of the isolates with the metabolism of xylose, glucose, and ethanol in the original strain, the isolates showed improved properties in the assumed bottlenecks of xylose metabolism. The xylose uptake rate was increased almost 2-fold. Activities of the key enzymes in the pentose phosphate pathway (transketolase, transaldolase) increased 2-fold while the concentrations of their substrates (pentose 5-phosphates, sedoheptulose 7-phosphate) decreased correspondingly. Under anaerobic conditions, on minimal medium with 45 g l–1 xylose, the ethanol productivity (in terms of cell dry weight; CDW) of one of the isolates increased from 0.012 g g–1 CDW h–1 to 0.017 g g–1 CDW h–1 and the yield from 0.09 g g–1 xylose to 0.14 g g–1 xylose, respectively.  相似文献   

7.
Rates of O2 consumption and CO2 production, telemetered body temperature (Tb) and activity level were recorded from adult and subadult water shrews (Sorex palustris) over an air temperature (Ta) range of 3–32°C. Digesta passage rate trials were conducted before metabolic testing to estimate the minimum fasting time required for water shrews to achieve a postabsorptive state. Of the 228 metabolic trials conducted on 15 water shrews, 146 (64%) were discarded because the criteria for inactivity were not met. Abdominal Tb of S. palustris was independent of Ta and averaged 38.64±0.07°C. The thermoneutral zone extended from 21.2°C to at least 32°C. Our estimate of the basal metabolic rate for resting, postabsorptive water shrews (96.88±2.93 J g–1 h–1 or 4.84±0.14 ml O2 g–1 h–1) was three times the mass-predicted value, while their minimum thermal conductance in air (0.282±0.013 ml O2 g–1 h–1) concurred with allometric predictions. The mean digesta throughput time of water shrews fed mealworms (Tenebrio molitor) or ground meat was 50–55 min. The digestibility coefficients for metabolizable energy (ME) of water shrews fed stickleback minnows (Culaea inconstans) and dragonfly nymphs (Anax spp. and Libellula spp.) were 85.4±1.3% and 82.8±1.1%, respectively. The average metabolic rate (AMR) calculated from the gas exchange of six water shrews at 19–22°C (208.0±17.0 J g–1 h–1) was nearly identical to the estimate of energy intake (202.9±12.9 J g–1 h–1) measured for these same animals during digestibility trials (20°C). Based on 24-h activity trials and our derived ME coefficients, the minimum daily energy requirement of an adult (14.4 g) water shrew at Ta = 20°C is 54.0 kJ, or the energetic equivalent of 14.7 stickleback minnows.  相似文献   

8.
Idli, a traditional cereal/legume-based naturally fermented steamed product with soft and spongy texture is highly popular and widely consumed in India. The inherent viable bacterial populations of mesophilic aerobes and lactics in idli batter increased in their numbers with time at 35 °C, reaching numbers in the range of 13 to 15 log10 CFU g–1. Simultaneously, the pH level decreased from 6.2 to 4.4. Strains of Bacillus cereus F 4810, Escherichia coli D 21 and Staphylococcus aureus FRI 722 (foodborne pathogens) introduced into the idli batter at an initial level of 4.3 log10 CFU g–1 was able to survive and grow well in an initial period of 6 h. However, the strain of S. aureus showed a constant increase in its numbers reaching 9.3 log10 CFU g–1 in 12 h. The addition of plantaricin LP84, a bacteriocin produced by Lactobacillus plantarum NCIM 2084 to idli batter at 1% (v/w) level was able to retard the growth of the inoculated cultures during fermentation. Two aspects were established from this study, (i) that foodborne pathogens occurring as contaminants in idli batter can survive and grow under conditions of natural fermentation and (ii) the efficacy of a lactic bacteriocin as a potential food biopreservative.  相似文献   

9.
Bacteriological surveillance is little applied in management of equine frozen semen but it is quite important to verify the microbial contamination in order to find out the chance of transmission of pathology to the mare in AI. Authors describe a qualitative and quantitative analysis for bacterial contamination on long time (3–17 years) equine frozen semen stored in liquid nitrogen. The semen checked, produced in Italy and in another Europe country, was cryopreserved in liquid nitrogen inside sealed plastic straws. One hundred and ten straws were checked out for pathogenic and no pathogenic bacteria, aerobes and anaerobes and fungi (moulds and yeasts). The Total Microbial Charge was quite variable with an average of about 1.4 × 105 CFU/ml. Mostly the microbial agents identified were fungi (17.5%), Enterobacter-coccus spp. (15%), Pseudomonas spp. (6.25%), Stenothophomonas maltophila (6.25%) and anaerobic bacteria like Propionibacterium granulosum (7.5%) and Clostridium spp. (3.75%). 3.75% were unidentified Gram-negative rod and cocci. Streptococcus spp., Staph. aureus, E. coli, Th. equigenitalis and Mycoplasma spp. were not detected. The most represented species were Enterobacter-coccus spp. (1.1 × 105 CFU/ml), St. maltophila (8 × 104 CFU/ml) and Pr. granulosum (7 × 104 CFU/ml) while yeast and even more moulds were little abundant (4.7 × 104 and 3.4 × 104 CFU/ml respectively). The knowledge of equine frozen semen microbial quality is essential to check out transmission of venereal disease and improve the quality of cryopreserved germplasm.  相似文献   

10.
Ultraviolet sunscreen compounds in epiphytic red algae from mangroves   总被引:3,自引:0,他引:3  
Karsten  Ulf  Sawall  Thomas  West  John  Wiencke  Christian 《Hydrobiologia》2000,432(1-3):159-171
Epiphytic red algae of the order Ceramiales from mangroves and salt marshes (nine species from Bostrychia, three from Stictosiphonia and four from Caloglossa) produce varying levels of the UV-absorbing compounds mycosporine-glycine, shinorine, porphyra-334, palythine, asterina-330 and palythinol, a suite of substances chemically assigned as mycosporine-like amino acids (MAAs). Mean MAA levels varied from 0.02 to 12.8 mg g–1 DW in field-collected and laboratory cultured specimens. While in field samples of Bostrychia montagneiHarvey, Bostrychia radicans (Montagne) Montagne and Caloglossa apomeiotica J.West et G.Zuccarello MAA concentrations were generally higher compared to cultured plants of the same taxa, Bostrychia tenella(Lamouroux) J.Agardh did not show such a difference. Catenella caespitosa (Withering) L.Irvine, Catenella impudica (Montagne) J.Agardh and Catenella nipae Zanardini (Gigartinales, Caulacanthaceae) produce two novel UV-absorbing compounds: MAA-1 (1.4–4.3 mg g –1 DW) and MAA-2 (0.1–1.0 mg g–1 DW), which absorb at 334 nm and 320 nm, respectively. In laboratory culture of Bostrychia moritziana when photosynthetically active radiation (PAR) was increased from 20 to 40 mol photons m–2 s–1, the total level of palythinol increased by 85% (from 2.0 to 3.7 mg g–1 DW). In a culture of Caloglossa leprieurii when PAR was increased from 40 to 80 mol m–2 s–1the porphyra-334 content increased by 77% (from 3.1 to 5.5 mg g–1 DW). Extremely high MAA contents of >30 mg g–1 DW were detected in mature tetrasporangial sori prepared from two isolates of laboratory-cultured reproductive Caloglossa apomeiotica compared to vegetative plants (about 10 mg MAAs g–1 DW) indicating tetraspores loaded up with UV-sunscreens. All data demonstrate that mangrove red algae contain high MAA concentrations, particularly the reproductive structures, and hence these compounds may act as biochemical photoprotectants against exposure to UV-radiation.  相似文献   

11.
The food, feeding habits and growth of 0+ Alestes nurse (Rüppel) from the Blue Nile near Khartoum, was investigated. 0+ A. nurse were observed to change their food from phytoplankton and small zooplankton during their pre-metamorphosis stages, to larger zooplankton (Daphnia spp., Chydorus sp.) and insects (larvae, pupae and imagines) during their post-metamorphosis stage.Their growth in length and weight was characterized by two distinct stanzas; during the first stanza, the fish increased in total length at a rate of 0.196 mm mm–1 wk–1, and in wet weight at a rate of 0.430 g g–1 wk–1. These rates were reduced during the second stanza to 0.046 mm mm–1 and 0.080 g g–1 wk–1, respectively. The calculated value of the exponent b in their length-weight relationship suggested that their growth was allometric.  相似文献   

12.
The bacterial populations of anoxic sediments in a eutrophic lake (Aydat, Puy-de-Dôme-France) were studied by phospholipid fatty acid analysis (PLFA) and also by culturing heterotrophic bacteria under strictly anaerobic conditions. The mean PLFA concentrations of prokaryotes and microeukaryotes were 5.7 ± 2.9 mgC g–1 DS and 9.6 ± 6.7 mgC g–1 DS, respectively. The analysis of bacterial PLFA markers was used to determine the dynamics of the Gram-positive and Gram-negative species of anaerobic bacteria, Clostridiae, and sulfate-reducing bacteria. Throughout the sampling period the concentrations of i15:0 (from 20 nmol g–1 DS to 130 nmol g–1 DS), markers of Gram-positive bacteria, were higher than those for Gram-negative bacteria. The dynamics of Clostridiae (Cy15:0) paralleled those of sulfate-reducing bacteria that were marked by i17:17. Partial 16S rDNA sequencing and the physiological study of the various fermenting strains, whose abundance in the superficial sediment layer was 1.1 ± 0.4 × 106 cells mL–1, showed that all the isolates belonged to the Clostridiae and related taxa (Lactosphaera pasteurii, Clostridium vincentii, C. butyricum, C. algidixylanolyticum, C. puniceum, C. lituseburense, and C. gasigenes). All the isolates were capable of metabolizing a wide range of organic substrates.  相似文献   

13.
A study was conducted to determine the diversity of 2-, 3-, and 4-chlorobenzoate (CB) degraders in two pristine soils with similar physical and chemical characteristics. Surface soils were collected from forested sites and amended with 500 g of 2-, 3-, or 4-CB g–1 soil. The CB levels and degrader numbers were monitored throughout the study. Degraders were isolated, grouped by DNA fingerprints, identified via 16S rDNA sequences, and screened for plasmids. The CB genes in selected degraders were isolated and/or sequenced. In the Madera soil, 2-CB and 4-CB degraded within 11 and 42 d, respectively, but 3-CB did not degrade. In contrast, 3-CB and 4-CB degraded in the Oversite soil within 14 and 28 d, respectively, while 2-CB did not degrade. Approximately 107 CFU g–1 of degraders were detected in the Madera soil with 2-CB, and the Oversite soil with 3- and 4-CB. No degraders were detected in the Madera soil with 4-CB even though the 4-CB degraded. Nearly all of the 2-CB degraders isolated from the Madera soil were identified as a Burkholderia sp. containing chromosomally encoded degradative genes. In contrast, several different 3- and 4-CB degraders were isolated from the Oversite soil, and their populations changed as CB degradation progressed. Most of these 3-CB degraders were identified as Burkholderia spp. while the majority of 4-CB degraders were identified as Bradyrhizobium spp. Several of the 3-CB degraders contained the degradative genes on large plasmids, and there was variation between the plasmids in different isolates. When a fresh sample of Madera soil was amended with 50, 100, or 200 g 3-CB g–1, 3-CB degradation occurred, suggesting that 500 g 3-CB g–1 was toxic to the degraders. Also, different 3-CB degraders were isolated from the Madera soil at each of the three lower levels of 3-CB. No 2-CB degradation was detected in the Oversite soil even at lower 2-CB levels. These results indicate that the development of 2-, 3-, and 4-CB degrader populations is site-specific and that 2-, 3-, and 4-CB are degraded by different bacterial populations in pristine soils. These results also imply that the microbial ecology of two soils that develop under similar biotic and abiotic environments can be quite different.  相似文献   

14.
The SENTRY Antimicrobial Surveillance Program was established to monitor the occurrence and antimicrobial susceptibility of bacterial pathogens via an international network of sentinel hospitals. Twenty European hospitals referred a total of 887 urinary tract infection (UTI) isolates to the European SENTRY reference laboratory during the period October–December 1997. Ninety percent of the referred species were represented by Escherichia coli (52%), Enterococcus spp. (12%), Klebsiella spp. (7%), Proteus spp. (7%), Pseudomonas aeruginosa (7%), and Enterobacter spp. (5%). The susceptibility of E. coli isolates to penicillins was less than 60%, while almost all of the isolates were susceptible to piperacillin/tazobactam (98% susceptibility), cephalosporins (98%), and carbapenems (100%). Amikacin was the best aminoglycoside (99.8% susceptibility). The susceptibility to quinolones was only 88–89%, with highest levels of resistance observed for isolates from Portugal, Italy, England, The Netherlands, and some centers in France, Spain, and Poland. The susceptibility of Klebsiella spp. to the newer generations of cephalosporins was 82–95% and to the carbapenems 100%. Amikacin was again the best aminoglycoside (94% susceptibility). The susceptibility of Enterobacter spp. to any ß-lactam antibiotic was poor, except for the carbapenems (100% susceptibility) and cefepime (90% susceptibility), while the susceptibility to aminoglycosides was 80–89%. Proteus spp. showed complete susceptibility to cefepime, ceftriaxone, the carbapenems, and piperacillin/tazobactam, while the susceptibility of P. aeruginosa isolates was poor, with best results for the carbapenems (susceptibility 89%), piperacillin/tazobactam (susceptibility 84%), and amikacin and ticarcillin (susceptibility to both 80%). Enterococcus spp. showed the highest susceptibility to vancomycin (98%), teicoplanin (98%), and ampicillin (94%).  相似文献   

15.
Summary Effects of temperature and seedling age on survival of perennial ryegrass (Lolium perenne L.) seedlings grown on sand-wheat wholemeal cultures of different isolates ofFusarium spp. (9 isolates),Pythium spp. (9 isolates), andChaetomium spp. (1 isolate) are reported. Some isolates were virulent over the whole range of temperatures tested (7.5–27.5°C). The virulence of others depended on temperature. Most isolates were less virulent at intermediate temperatures (12.5–22.5°C) than at higher or lower temperatures. At 25°C ryegrass seedlings were susceptible to fungal attack for only a limited period after germination commenced. This period differed for different fungi, but for most isolates tested, seedlings were resistant after 2–3 days.  相似文献   

16.
Summary The fungal airspora of a large hospital in Delhi Metropolis was studied from May 1989 – April 1991, using Andersen Six Stage Volumetric Sampler and Burkard Personal Slide Sampler. Simultaneously, samples were also collected from outside the hospital to act as a control. Samplers were operated for 10 min. each time, at 10 - day intervals. Additional samples were also collected from different sections of 3 other hospitals. Some of the dominant forms encountered wereCladosporium spp.,Aspergillus flavus, Smut,Fusarium spp.,Aspergillus niger, Alternaria spp.,Penicillium citrinum, Aspergillus versicolor, andPenicillium oxalicum. Aspergillus flavus showed significantly high concentration inside hospital (n=66, x=53 CFU m–3, p<0.05) as compared to outside air. The peak period for fungi was observed to be from June – September. The spore concentration was much lower in hospital units receiving filtered air as compared to control environment, but in naturally ventilated hospitals the concentration was similar to that of outside air.  相似文献   

17.
Japanese monkeys, Macaca fuscata, living in a cool temperate forest experienced energy crises in winter. We measured feeding times and feeding rates (mass of foods eaten per unit time of feeding) in six different-sized, age–sex classes (1.2–12.6 kg body mass) in autumn and winter. One-, 2- and 3~4-year-olds spent 34–35% and 44–46% of the day feeding in autumn and winter, respectively. Monkeys less than 0 years old spent less time feeding (16–28%) than average in winter and autumn; adult females spent less (41%) in winter; and adult males spent less (25%) in autumn. All age–sex classes ate mainly fruits in autumn and the heavier classes fed more on tree bark than buds in winter. The feeding rate for fruits (2.3–53.5 g min–1) was nine to 12 times faster than those for buds (1.0– 4.8 g min–1) and bark (0.5–4.4 g min–1), and energy content did not differ among fruits (22.1 kJ g–1 dry mass), buds (19.9 kJ g–1 dry mass) and bark (23.2 kJ g–1 dry mass). Energy base feeding rates increased with body mass where the body mass exponent for buds (0.29) was smaller than those for bark (0.64) and fruits (0.63), which might be attributable to the unit size of food items and mass dependency of masticatory apparatus. Our monkeys obtained two to five times more energy in autumn (1567–1150 kJ day–1) than in winter (604–3020 kJ day–1). Adult females obtained 60% of expected energy expenditure and other classes obtained 77–88% of that in winter.  相似文献   

18.
Zhang SJ  Yang M  Yang QX  Zhang Y  Xin BP  Pan F 《Biotechnology letters》2003,25(17):1479-1482
Three reactive dyes were rapidly adsorbed by the mycelium pellets of Penicillium oxalicum. Dye removal of Reactive Blue 19 was up to 60% in 10 min and 91% in 80 min. Dye adsorption isotherms fitted Langmuir model well and the maximum adsorption capacities at 20 °C were calculated to be 160 mg g–1 for Reactive Blue 19, 122 mg g–1 for Reactive Red 241 and 137 mg g–1 for Reactive Yellow 145, respectively. The pellets exhibited a high dye adsorption capacity (80–180 mg g–1) for all of the 3 dyes over a wide pH range (pH 2–10), and the maximum adsorption was obtained at pH 2. The adsorption capacity was mildly increased by increasing salinity.  相似文献   

19.
In this study, enumeration and identification of total aerobic heterotrophic bacteria and petroleum-utilizing bacteria as well as the degradative potential of petroleum-utilizing bacterial isolates were carried out. The average counts of total aerobic heterotrophic bacteria in cow dung and poultry manure were 74.25 × 105 c.f.u. g−1 and 138.75 × 105 c.f.u. g−1 respectively. Acinetobacter sp, Bacillus sp, Pseudomonas sp, and Serratia spp. occurred as aerobic heterotrophs in both cow dung and poultry manure. However, Alcaligenes spp. occurred only in cow dung while, Flavobacterium sp, Klebsiella sp, Micrococcus sp, and Nocardia spp. occurred only in poultry manure as aerobic heterotrophs. The average counts of petroleum-utilizing bacteria in cow dung and poultry manure were 9.25 × 105 c.f.u. g−1 and 17.25 × 105 c.f.u. g−1 respectively. Pseudomonas spp. occurred as petroleum utilizer in both cow dung and poultry manure. However, Bacillus spp. occurred only in cow dung while Acinetobacter spp. and Micrococcus spp. occurred only in poultry manure as petroleum utilizers. Relative abundance of petroleum utilizers in total aerobic heterotrophs ranged from 6.38% to 20.00% for cow dung and from 9.38% to 17.29% for poultry manure. Introduction of pure cultures of petroleum-utilizing bacteria from cow dung and poultry manure into sterile oil-polluted soil revealed oil degradation in one week period.  相似文献   

20.
Bacterial strains were randomly isolated from soil using three different media with glucose (TG), Tryptone Soya Broth (TTS), and succinate (TS) as carbon sources. Plate counts obtained were 12.0×107, 4.5 ×107, and 1.5×107 g–1 soil dry weight, respectively. The strains were characterized phenotypically by the API 20B test system. A cluster analysis of all isolates revealed 40 biotypes at 80% similarity, 23 in TG, 29 in TTS, and 27 in TS. Each of the 10 most common biotypes contained 10 to 2.5% of the isolates, and 17 biotypes contained one or two isolates. The common biotypes were unevenly distributed among the isolates from the different media. About 20% of the isolates from TG and TTS were unique for the particular medium, whereas among the isolates from TS, about 60% were unique. Thirty percent of the isolates belonged to biotypes that were common to all three populations. All media gave approximately the same high diversity measured as Shannon index and Equitability, indicating no direct correlation between plate count and diversity.  相似文献   

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