Determination of Mercury Content in a Shallow Firn Core from Greenland by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry     

Jacqueline L. Mann  Stephen E. Long  Christopher A. Shuman  W. Robert Kelly 《Water, air, and soil pollution》2005,163(1-4):19-32

The total mercury content was determined in 6 cm sections of a shallow 7 m firn core and in surrounding surface snow from Summit, Greenland (elevation: 3238 m, 72.58^°N, 38.53^°W) collected in May 2001 by isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICP-MS). The focus of this research was to evaluate the capability of the ID-CV-ICP-MS technique for measuring trace levels of Hg typical of polar snow and firn. Highly enriched ²⁰¹Hg isotopic spike is added to approximately 10 mL melted core and thoroughly mixed. The Hg²⁺ in the sample is reduced on line with tin(II) chloride (SnCl₂) and the elemental Hg (Hg^°) vapor pre-concentrated onto gold gauze using a commercial amalgam system. The Hg is then thermally desorbed and introduced into a quadrupole ICP-MS. The blank-corrected Hg concentrations determined for all samples ranged from 0.25 to 1.74 ng/L (ppt) (average 0.59 ± 0.28 ng/L (1σ)) and fall within the range of those previously determined by Boutron et al. [Geophys. Res. Lett. 25, 1998, 3315–3318] (≤ 0.05–2.0 ng/L) for the Summit site. The average blank value was 0.19 ± 0.045 ng/L (n = 6, 1σ) and the method detection limit was 0.14 ng/L. The Hg values specifically for the firn core range from 0.25 to 0.87 ng/L (average 0.51 ± 0.13 ng/L (1σ)) and show both values declining with time and larger variability in concentration in the top 1.8 m.  相似文献   

BEYOND URANIUM WITH THE MAGNETOOPTIC METHOD OF ANALYSIS     

Papish J  Shuman AC 《Science (New York, N.Y.)》1934,79(2048):297-298

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Swine abscesses caused by Lancefield's group E streptococci. XII. Specificity of serological tests for their detection with relation to nongroupable beta hemolytic streptococci   总被引：2，自引：0，他引：2  

R D Shuman  G E Wessman 《The Cornell veterinarian》1974,64(2):178-200

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Swine abscesses caused by Lancefield's group E streptococci. V. Specificity of the precipitin test for their detection with relation to streptococcal antigens of groups P and U and Corynebacterium pyogenes   总被引：2，自引：0，他引：2  

R D Shuman  R L Wood  N Nord 《The Cornell veterinarian》1969,59(1):102-120

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Development and evaluation of a flow cytometry microsphere assay to detect anti-histone antibody in dogs     

Paul S  Wilkerson MJ  Shuman W  Harkin KR 《Veterinary immunology and immunopathology》2005,107(3-4):315-325

Anti-nuclear antibody (ANA) is one of the diagnostic parameters that support a diagnosis of autoimmune disorders in humans, dogs, and horses, particularly the condition systemic lupus erythematosus (SLE). The most commonly used method for detecting ANA in canine serum is the indirect immunofluorescence antibody assay (IFA) that detects dog IgG with reactivity towards mammalian cell nuclei. Interpretation of the IFA results is very subjective and dependent on the source of tissue/cellular substrate. We have developed a flow cytometry based assay to detect canine serum antibodies specific to histones. Histones were chosen as the target antigen because these nuclear proteins are the most common nuclear substrate for ANA in dogs with SLE. Microsphere beads were coated with histones and incubated with canine sera. Bound anti-histone antibodies were detected by FITC-conjugated rabbit F(ab')2 anti-dog IgG. Sera from four groups of dogs (47 dogs total) were tested for anti-histone antibodies and compared with the traditional IFA assay. The groups included 15 healthy dogs, 15 dogs with noninflammatory diseases, 9 dogs with polyarthritis and positive ANA, and 8 German shepherds with perianal fistulas. The microsphere assay results indicated that only one dog in the noninflammatory group and four out of nine dogs in the polyarthritis group had mean fluorescent intensity values above our established cut-off (defined as 2 S.D. above the mean of healthy controls). There was moderate agreement between the anti-histone assay and the traditional ANA (kappa statistic=0.54). Absorption of ANA positive serum with total histones dramatically diminished the fluorescent signal detected by flow cytometry and the speckled nuclear pattern observed by IFA, whereas preabsorption did not change the diffuse nuclear staining pattern. These findings indicate that the anti-histone assay will not replace the ANA test and that other nuclear proteins, such as ribonucleoproteins may contribute to the diffuse ANA patterns.  相似文献   

Alterations in normal canine platelets during storage in EDTA anticoagulated blood     

Wilkerson MJ  Shuman W 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2001,30(3):107-113

Abstract: Flow cytometric detection of platelet surface-associated IgG (PSAIgG) can be used to determine whether immunologic factors are contributing to thrombocytopenia in dogs. In vitro alterations in platelet activation and morphology, however, could impact the results of this test. The purpose of this study was to determine whether the PSAIgG test for immune-mediated thrombocytopenia was valid on whole blood in EDTA anticoagulant after 24–72 hours of storage, and to characterize other alterations in canine platelets that could impact immunologic testing. Platelets were harvested and analyzed immediately after blood collection and after 24, 48, and 72 hours of storage at 4°C. Spontaneous and thrombin-induced changes in the following platelet parameters were evaluated using flow cytometric techniques: PSAIgG, platelet microparticle formation, membrane expression of P-selectin and glycoprotein CD61, exogenous IgG binding, surface-exposed phosphatidylserine, and fibrinogen binding. The amount of PSAIgG increased 6-to 9-fold in stored samples compared with fresh samples. Platelet microparticle formation was spontaneous in stored samples and increased significantly over time. Membrane phosphatidylserine, P-selectin, and fibrinogen binding were not altered by storage, indicating that platelet activation was minimal in stored samples. Although storage decreased the percentage of platelets positive for CD61 by 8-to 10-fold compared with fresh samples, activation by high-dose thrombin partially restored the percentage of CD61-positive platelets in 24-hour-old samples. In conclusion, even though platelets stored in EDTA for up to 72 hours remain in a resting state, aged platelets have an increased tendency to form microparticles and have increased surface IgG and decreased surface CD61, which may contribute to false-positive results for tests of immune-mediated thrombocytopenia.  相似文献   

野生黄鼬消化管组织结构的观察   总被引：1，自引：1，他引：0  

王珏  王政富  唐菽蔓 《野生动物》2008,29(1):11-14

通过组织学观察,探讨野生黄鼬消化管的组织结构特点.将8只野生黄鼬经乙醚麻醉后处死,解剖取食管、胃、小肠、大肠,制作石蜡切片,观察其组织结构.结果显示野生黄鼬食管的黏膜为复层扁平上皮,食管腺发达,肌层以骨骼肌为主.胃贲门部有发达的皱襞和贲门腺;胃底腺有大量的主细胞和壁细胞;胃大弯部的腺体以壁细胞为主,仅有少量主细胞;胃幽门部有发达的幽门腺和大量壁细胞.十二指肠黏膜层有小肠腺,内有潘氏细胞存在,黏膜下层含有十二指肠腺;空肠可见孤立淋巴小结、弥散淋巴组织及集合淋巴小结.结肠无皱襞和肠绒毛,大肠腺排列紧密,其中杯状细胞特别多;直肠固有膜内有发达的大肠腺.所以野生黄鼬消化管的特点是胃各部胃腺发达,壁细胞特别多.  相似文献   

Alkaline phosphatase is a useful cytochemical marker for the diagnosis of acute myelomonocytic and monocytic leukemia in the dog          下载免费PDF全文

Tracy Stokol  Deanna M. Schaefer  Martha Shuman  Nicole Belcher  Lynn Dong 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2015,44(1):79-93

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Peripheral Blood Lymphocyte Subpopulations and Immunoglobulin Concentrations in Healthy Foals and Foals with Rhodococcus equi Pneumonia     

M. Julia B.F. Flaminio  Bonnie R. Rush  Wilma Shuman 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1999,13(3):206-212

Infectious diseases are common in foals aged 1-5 months. The objectives of this investigation were to evaluate immunologic parameters in foals from birth to weaning to establish reference values for the proportion of circulating lymphocytes that were helper (CD4+) or cytotoxic (CD8+) T cells, or B cells; to measure serum immunoglobulin (IgM and IgG) concentrations; and to compare these immunologic parameters to values in foals with naturally occurring Rhodococcus equi pneumonia and in adult horses. Peripheral blood lymphocyte subpopulations were determined by flow cytometric analysis, and serum IgG and IgM concentrations were determined by radial immunodiffusion. Flow cytometric analysis of lymphocyte subpopulations suggested age-related changes in the cell-mediated immune system in horses. Absolute circulating CD4+ and CD8+ T lymphocytes and B cells increased linearly up to 3 months of age. Circulating B cell concentrations from birth to 6 months of age were greater than values in adult horses and the lymphocyte differences among the age groups are mainly due to variation in B lymphocytes. Both absolute and proportional B cell concentrations were greater in foals with R equi pneumonia than in healthy foals at the same age. The increase in absolute cell counts of each subpopulation was dependent on the increase of absolute peripheral blood lymphocyte count. Serum IgG concentration increased linearly from 1 to 3 months of age, and serum IgM concentrations increased from 1 to 6 months of age. These data suggest age-dependent cell-mediated and humoral development in young foals.  相似文献   

高校园林绿地景观探讨     

商书满 《江西林业科技》2007,(1):62-64

以湖南工业大学为例,探讨高校园林绿地景观规划设计的原则、构思、方法。以期对当今高校园林绿地规划设计提供一种思路。  相似文献