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1.
The bioavailability of field‐aged Cd and Cu was calculated, and compared to the total concentrations determined by acid digestion. Only 0.60–4.15% for Cd and 0.59–9.43% for Cu were found to be bioavailable when determined by stomach‐phase extraction. The incorporation of bioavailability reduced more than 90% of the calculated risk of the metals at the site of study. It should be noted that such a reduction may not be generalized and the site‐specific bioavailability needs to be determined case by case. 相似文献
2.
笔者报告４例胃平滑肌肉瘤的临床及ＣＴ表现。其中３例经手术病理证实，１例经胃镜活检病理证实。３例ＣＴ明确诊断，１例误诊。本文回顾性阅片并参考有关文献，介绍胃平滑肌肉瘤的影响像诊断，重点讨论其ＣＴ特征、ＣＴ检查限度及鉴别诊等问题，提出了胃部ＣＴ检查能对此病定性诊断并为临床治疗提供可靠的依据。 相似文献
3.
CT胃仿真内窥镜成像技术临床应用的探讨 总被引：2，自引：0，他引：2
目的：探讨CT胃仿真内窥镜成像技术的原理,方法,临床应用材料与方法：将螺旋CT容积扫描数据传输到工作站,通过软件功能重建出沿空腔器官中轴行程一致的多幅器官内表面图像,再用电影功能一次回放,获得仿真内窥镜效果用此方法检查10例及正常人其中胃部疾病患者5例.全部病例均经胃纤维内窥镜及手术病例证实结果：胃仿真内窥镜获得类似纤维内窥镜显示空腔器官腔壁或腔内病变形态的效果结论：CT胃仿真内窥镜提供了一种无创伤性的诊断方法,可作为纤维内窥镜的补充手段. 相似文献
4.
The aim of this study was to determine the extent Nephrops consumes plastics in the Clyde Sea and if this intake occurs through their diet. Plastic contamination was found to be high in Nephrops, 83% of the animals sampled contained plastics (predominately filaments) in their stomachs. Tightly tangled balls of plastic strands were found in 62% of the animals studied but were least prevalent in animals which had recently moulted. No significant difference in plastic load was observed between males and females. Raman spectroscopy indicated that some of the microfilaments identified from gut contents could be sourced to fishing waste. Nephrops fed fish seeded with strands of polypropylene rope were found to ingest but not to excrete the strands. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland and the high prevalence of plastics in Nephrops may have implications for the health of the stock. 相似文献
5.
Diet and feeding intensity of the portunid crab Polybius henslowii were studied during the spring of 2004 along Galician and Cantabrian continental shelves (NW Iberian Peninsula) between 78 and 287 m. The area had been affected by the Prestige oil spill in November 2002, with different sectors at different levels of pollution: highest in between Miño River and Cape Finisterre (MF) and from there to Estaca de Bares Point (FE) and lowest from Estaca to Cape Peñas (EP). From 37272 specimens collected in 59 bottom hauls, 342 were analysed for stomach fullness and diet composition. Stomach fullness was lower in FE, but with no significant differences among sectors. Diet was a mixture of pelagic and benthic prey: cephalopods (Ilex coindetti), brachyurans (P. henslowii) and polychaetes (Glycera sp.). Other prey were beloniform eggs and fish remains. Two stress markers were also studied in some specimens: Acetylcholinesterase (a neurotoxicity marker) varied among sampled areas, while lipid peroxidation (an oxidative stress marker) did not. Changes in trophic variables, distribution and density were analysed in relation to depth, surface and bottom T, surface Chl a from satellite imagery and tar aggregate concentration in sediments. Along Galician and Cantabrian coasts prey availability, linked to productivity level, seems to be the main factor affecting P. henslowii diet and distribution. Interannual abundance variability seems to be controlled by large-scale climatic conditions (NAO index). This natural variability masks possible effects induced by the oil spill. 相似文献
6.
本文对东方对虾消化道及肝胰脏进行大体解剖和组织学观察,并将其结构与功能同其它主要十足动物作比较。 前肠和后肠内壁有几丁质层覆盖,中肠则没有。食道壁向四个角落内褶,在其表皮层之下的结缔组织中充满皮肤腺,环肌层连续,纵肌成束分散排列:胃的组织学结构除没有皮肤腺分布外,大体与食道相似。中肠从胸部延伸到第六腹节前区,约占消化道总长的60％,其上皮是一层柱状细胞,环肌层薄,纵肌成束分散排列;中肠前,后盲囊分别从中肠的前端和后端发出。后肠是一短管,内壁突出四个大的垫状隆脊,肛门开口于尾节腹面,和食道一样后肠壁分布大量皮肤腺:后肠上皮由单层柱状细胞组成,环肌层连续,纵肌在后肠前段成束分散排列于环肌之下,在后段则在环肌层之上。肝胰脏由许多分支肝小管构成,肝小管内壁为单层柱状上皮,中央为管腔:肝管细胞分为分泌细胞、吸收细胞、纤维细胞和原始细胞四种。原始细胞是一种未分化的细胞,分布于肝小管末端。 相似文献
7.
Stomach content analysis of eastern North Pacific groundfish has been conducted routinely by researchers interested in understanding trophic interactions between key predator species and their prey. Identification of prey by traditional morphological methods has limitations however, due to the loss of identifiable characters from digestion and morphological similarities between taxa. Furthermore, some forage fish (e.g., osmerids, ammodytids, and juvenile gadids), common prey of Bering Sea and Gulf of Alaska groundfish, are difficult to distinguish because of their slender or fusiform shape, disarticulating easily during digestion. DNA-based identification methods were developed to differentiate among 18 fish species, some that are found at depths greater than 200 m, from four taxonomic families: Ammodytidae and Osmeridae (forage fish), Pleuronectidae (flatfish), and Gadidae (gadid fish). Polymerase chain reaction (PCR) amplification of a 739 basepair section of mitochondrial DNA cytochrome c oxidase I and an 862 basepair section of mitochondrial DNA cytochrome b was followed by restriction digest assays and resulted in species level resolution for 16 of 18 species of interest. PCR restriction digest assays applied to fish prey from stomach contents of groundfish indicated the presence of several target species, eulachon (Thaleichthys pacificus), walleye pollock (Gadus chalcogrammus), searcher (Bathymaster signatus), rock sole (Lepidopsetta bilineata), yellowfin sole (Limanda aspera) and either Bering flounder (Hippoglossoides robustus) or flathead sole (H. elassodon). The PCR restriction digest protocols improved the identification rate of predated fish from stomach contents compared to identification by conventional taxonomic methods alone, and DNA sequence analysis further resolved identification of unknown prey fish samples. 相似文献
8.
Marine mammals and marine birds perform diving to forage underwater. Recent technological advances have led to rapid progress in our understanding of diving behavior, but additional research is required into feeding behavior to determine the timing of prey ingestion, prey mass, and prey type. To achieve a comprehensive understanding of the foraging and diving behavior of these endotherms, it is essential to integrate information on feeding behavior with other data. The challenges involved in developing an appropriate research method have been addressed, and several methods have been tested and used in the field, including the stomach temperature method, the esophagus method for marine birds, the stomach temperature telemeter method for seals, and the beak magnet sensor method. In the present study, I review these methods, suggest the necessity of their further development in field studies, and propose a new practical method that involves the measurement of jaw movements underwater as an indicator of the feeding behavior of seals. 相似文献
9.
European whitefish (Coregonus lavaretus) is a dominant zooplanktivorous fish in many praealpine lakes and of great commercial interest. Estimation of prey consumed by European whitefish is essential for the prediction of top down effects in the pelagic zone. Whitefish is known to feed selectively on cladocerans. Quantitative estimates of prey consumed by whitefish are often not easy to get because stomachs frequently contain only degraded fragments of already digested prey. In this study stomach contents of European whitefish which were composed of digested, degraded prey were analyzed. Daphnid prey could be quantified by the number of mandibles divided by two, the number of head capsules and abdomina present. Predatory cladocerans could be quantified by the number of mandibles divided by two and the number of tail appendages present. For stomachs which contained heavily digested fragments counting the mandibles proved to be a useful and sometimes the only applicable means to quantify prey items. Other body parts, like structured legs which were broken into many pieces, were unsuited to quantify prey items. 相似文献
10.
泥螺消化道内的细菌学分析 总被引：1，自引：0，他引：1
泥螺(Ｂｕｌｌａｃｔａｅｘａｒａｔａ)隶属于软体动物门,腹足纲 ,后鳃亚纲,头盾目 ,阿地螺科。其味道鲜美,具有较高的营养价值和经济价值 ,是浙江沿海重要的滩涂养殖品种,至２０００年全省养殖面积已达约１１３００ｈａ。泥螺的生长是以不断吞食周围滩涂中的涂泥和底栖藻类等为营养基础 ,已知滩涂沉积物及动植物碎屑中所含有的微生物从事着大量的转化和分解工作［４］,它们在泥螺体内又会怎样呢 ?为探索泥螺的消化生理功能及与养殖、病害和防治的关系,本文从泥螺消化道内的细菌菌群组成与功能研究入手作初步分析。关于贝类体内的细菌学调查… 相似文献