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排序方式: 共有1464条查询结果,搜索用时 101 毫秒
981.
Herbert Valensise Elena Vaquero Caterina De Carolis Elisa Stipa Roberto Perricone Domenico Arduini Carlo Romanini 《黑龙江环境通报》1995,15(6):509-517
Antiphospholid antibodies are associated with fetal distress and fetal death. Although different therapeutic regimens have been used, the incidence of fetal growth retardation varies between 30 and 60 per cent of reported cases. We report the evolution of fetal growth in patients with antiphospholipid antibody syndrome treated with high-dose intravenous immunoglobulins (IVIG). Fourteen patients with a history of recurrent spontaneous abortion and immunological diagnosis of antiphospholipid syndrome were followed longitudinally. Intravenous immunoglobulin at a dose of 0.5 g/kg body weight for two consecutive days was started from the fifth week of pregnancy and repeated every 4 weeks until the 33rd week of gestation. Fetal biometry was evaluated longitudinally from the appearance of the gestational sac at 4 weekly intervals. In the period between 26 and 34 weeks, the frequency of evaluation was increased to every 14 days. Data obtained were compared with a control group of 70 fetuses with uneventful pregnancies matched for gestational age. Neonatal weight is shown in relation to the centiles for the normal population. One patient out of 14 (7.1 per cent) developed gestational hypertension and abruptio placentae. No other pregnancy complications were seen. No proteinuria was found. The mean maternal age was 31.2±3.8 years. Median birth weight was 3433 g±287. The median centile of the birth weight was 65.3±18.6. Mean gestational age at delivery was 1.3 weeks. No fetal or neonatal growth retardation was seen. No significant differences were found in the biometrical parameters investigated in the various gestational ages vs. the control group (Student's t-test not significant); a significant increase in head circumference (P< 0.001) and abdominal circumference (P< 0.05) was found at 36–37 weeks gestational age in the IVIG-treated fetuses. The presence of antiphospholipid antibodies is considered detrimental for pregnancy outcome because of their negative effects on placental vascular perfusion and fetal transfer of metabolites. The use of IVIG seems to avoid or inhibit the reduced availability of nutrients for the fetal anabolic functions, as the expected reduction in fetal growth was not seen in our series. 相似文献
982.
Professor Umberto Nicolini Alessandra Kustermann Beatrice Tassis Roberto Fogliani Andrea Galimberti Elena Percivalle Maria Grazia Revello Giuseppe Gerna 《黑龙江环境通报》1994,14(10):903-906
Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16–30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and ⩾ 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results. 相似文献
983.
Elena Gullino Mario Abrate Ezio Zerbino Giuseppe Bricchi Pier Dino Rattazzi 《黑龙江环境通报》1993,13(5):411-416
A prenatal diagnosis of arthrogryposis multiplex congenita (AMC) has been carried out on a 19-week-old fetus by means of echography. The ultrasonographic characteristics were unnatural position of the four limbs associated with articular anomalies together with absence of active fetal movements. A therapeutic interruption of pregnancy was performed and the diagnosis was confirmed. At autopsy, architectural disorder of the motor neurons of the anterior medullary horn revealed a neuropathic pathogenesis of the arthrogryposis. Moreover, at the lumbar level the spinal cord was progressively replaced by heterotopic bony tissue which caused a more severe deformity of the lower limbs compared with the upper. The aspects of anatomo-pathological, genetic, and differential diagnosis are discussed showing the precocity of the prenatal diagnosis and the peculiarity of the aetiology of our case. 相似文献
984.
Resource value is often considered the most important nonstrategic variable in the fighting behavior of invertebrates. In
our study, we tested whether the experience of shells of a given quality, occupied in the recent past, might affect the agonistic
behavior of the hermit crab Pagurus longicarpus. We analyzed the fights battled by 84 test crabs against size-matched unknown rivals before (premanipulation phase) and after
(postmanipulation phase) having modified the quality of the domicile shell of the contestants. Specifically, we compared the
behavior of crabs that had been subject to either a worsening or an improvement in the quality of their shell with crabs that,
although being similarly subject to a shell manipulation, occupied a shell of the same quality as in the premanipulation phase.
We found that the crabs subject to a worsening in the quality of their shell were more aggressive than those subject to its
improvement and that the former were even more aggressive than those that occupied a bad quality shell also in the premanipulation
phase. Crabs seemed not to gather information about the opponent’s shell during fights or not to use this information, most
often behaving in accordance with the quality of the domicile shell. These results are clear in showing the role played by
the experience of a previously occupied shell, also confirming that the agonistic behavior of P. longicarpus is mainly based on decision rules of the type “own resource value dependency.” 相似文献
985.
Galina?K.?VasilyevaEmail author Ludmila?P.?Bakhaeva Elena?R.?Strijakova Patrick?J.?Shea 《Environmental Chemistry Letters》2003,1(3):179-183
The use of some adsorbents may decrease the toxicity of organic pollutants to microbes and plants during soil bioremediation. Experiments were conducted with 3,4-dichloroaniline (DCA) and 2,4,6-trinitrotoluene (TNT). Here we demonstrate that activated carbon can reduce the toxicity of readily available chemicals in soil by transferring them to a less available fraction. This process results in accelerated biodegradation of dichloroaniline by the inoculated Paracoccus denitrificans st. 3XA. In the case of TNT, activated carbon promotes strong binding through accelerated microbial reduction of its nitro-groups and catalytic chemical oxidation of the methyl-group and polymerisation or binding of the products formed. 相似文献
986.
987.
Transfer rate of pesticide residues from medicinal plants in different types of extractive solutions
Alexandru Mihai Florea Veronica Drumea Roxana Andreea Nita Adelina Bicu Laura Olariu Ligia Elena Dutu 《毒物与环境化学》2020,102(1-4):37-61
AbstractStarting from the suspicion that the medicinal herbs may contain traces of pesticides and taking into account the risks of patients being exposed to contaminated products, the aim of this research was to evaluate the pesticide residues and the degree of their transfer (%) in three types of preparations (infusion, decoctionand cold maceration), for four medicinal plant species very often used in phytotherapy (Rosmarini folium, Menthae folium, Saturejae herba and Basilica herba). For each type of plant product, four samples were purchased from different manufacturers and they have been analyzed using gas chromatography- tandem mass spectrometry. One out of four samples of the same plant species contain at least one pesticide residue above the maximum level and shows a significant transfer of these residues in aqueous extractive solutions during extraction. The highest rate of pesticide transfer from medicinal plants was identified in infusions, recommended by many manufacturers. 相似文献
988.
Martínez E Llobet I Lacorte S Viana P Barceló D 《Journal of environmental monitoring : JEM》2002,4(2):253-257
The present study focused on monitoring the concentration of 14 halogenated volatile organic compounds in surface waters, including sea, estuarine, river water and industrial effluents in order to determine the most ubiquitous compounds and their concentration levels, which were used to establish their geographical and temporal distribution. EPA Method 502, based on purge and trap techniques, was used. In this method volatile organic pollutants are extracted (purged) from the water sample by bubbling inert gas through the aqueous sample. Purged sample components are trapped in a cartridge containing the polymeric sorbent Tenax and, thereafter, the cartridge is heated and backflushed with helium to desorb the trapped sample components directly into a gas chromatograph with electron capture detector (GC-ECD). The linearity range of the method varied from 0.1 to 4 microg L(-1) with a limit of detection at the low microg L(-1) level. The present study consisted of a monthly monitoring of 46 points throughout Portugal, during 14 months. Chloroform was found in 50% of the samples analyzed, its presence being correlated to both agricultural and industrial activities. Other compounds detected were tetrachloroethylene, trichloroethylene, carbon tetrachloride and 1,2,4 trichlorobenzene, which were present in 10-20% of the samples at concentrations up to 18 microg L(-1). 1,1,2,2-Tetrachloroethane and its degradation product 1,1,2-trichloroethane were found in 5% of the samples, the levels of the latter being higher than those of the parent compound in most samples. Sporadic high concentrations of some volatile halogenated organic compounds were attributed to local uses as solvents. 相似文献
989.
Viñas P López-García I Merino-Meroño B Campillo N Hernández-Cordóba M 《Journal of environmental monitoring : JEM》2004,6(4):262-266
Liquid chromatography with hydride generation atomic absorption spectrometry as the detection system was applied to the separation and determination of inorganic tin, tributyltin, dibutyltin, monobutyltin, diphenyltin and monophenyltin. A reversed phase C18 column and a methanol/water/acetic acid (70:27:3, v/v/v) mixture containing 0.05%(v/v) triethylamine and 0.1%(w/v) tropolone as the mobile phase (isocratic elution) were used. Extraction of organotins from the samples was carried out using methanol containing 0.05%(w/v) tropolone, a process that was repeated twice. The supernatants were shaken with water and dichloromethane in a separating funnel and the organic phase was collected and evaporated to dryness. When the method was applied to the speciation of tin in fresh and canned mussels, no organotins above the detection limits were identified in any of the samples, inorganic tin being the only species detected. The reliability of the procedure was checked by analyzing the total tin content of the samples by electrothermal atomic absorption spectrometry and by speciation of tin in a certified reference material, mussel tissue (CRM 477). The method can be used for environmental monitoring of organotins contaminated samples. 相似文献
990.
Rosas I Velasco A Belmont R Báez A Martínez A 《Environmental pollution (Barking, Essex : 1987)》1993,80(3):255-264
An evaluation of water quality and phytoplankton composition position was carried out in order to determine the trophic conditions of Lake Patzcuaro (2035 m above sea level), a high altitude tropical lake. Temperatures ranged from 15 to 23 degrees C. Total phosphorus and inorganic nitrogen showed a seasonal variation; highest values coincided with the rainy season (0.48 and 2.1 mg litre(-1), respectively). Dissolved oxygen ranged from 2 to 7.9 mg litre(-1) at the surface and from 0.6 to 7.3 mg litre(-1) on the bottom, the lowest values being found in shallow zones. Average transparency varied from 0.62 to 1.4 m Secchi depth. Rainfall was a primary factor in seasonal variability as it influenced both physical and biological conditions by contributing to the transport and deposition of silt, which mixed with sinking algal cells. The composition of the surface phytoplankton segregated along five major divisions comprising a total of 49 species. General seasonal patterns of dominance alternated in a sequence beginning with Bacillariophyta, through Chlorophyta to Cyanophyta. Diatoms, the dominant group from February to early June, included Melosira granulata, Stephanodiscus sp., Synedra sp. and Fragilaria sp. During the rainy season (late June to September), Microcystis aeruginosa, Oscillatoria sp., Anabaena sp., Merismopedia sp., Crucigenia cuadrata, Oocystis lacustris, Selenastrum gracile, Mallomonas sp. and Tetraediella sp. were important. Melosira granulata was present throughout the period of study. Spatial and temporal variability in both physical and biological conditions make it difficult to assign a specific trophic state to Lake Patzcuaro. Nevertheless, analysis of the algal community indicates a generally mesotrophic condition. 相似文献