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101.
102.
Wolfgang Schwartz 《Propellants, Explosives, Pyrotechnics》1994,19(4):192-201
Shaped charge craters can be calculated in regards to depth and diameter profile using the SDM model named after Simon, DiPersio, and Merendino(3). Crater profiles calculated using the SDM formulae exhibit a systematic deviation if compared with test data from firings of certain MBB (now DASA) shaped charges into RHA. The calculated craters feature a significantly more trumpet-shaped profile than the measured holes in RHA This phenomenon is caused, at least partly, by the assumption in the SDM model that the break-up time and the jet diameter after break-up are constant. Radiographs of particulated jets provide evidence that the diameter is generally not constant, rather increases from tip to tail. The evaluation of such radiographs also leads to the conclusion of variable break-up times. Changing those two assumptions a modified set of SDM formulae was developed so that calculated and experimental crater profiles are in better agreement for the above mentioned MBB shaped charges. 相似文献
103.
Qingguo Tian Robeena M. Aziz Gary D. Stoner Teven J. Schwartz 《Journal of food science》2005,70(1):C43-C47
ABSTRACT: The capabilities of mass spectrometry for microscale determination of anthocyanins were investigated using high-performance liquid chromatography electrospray ionization mass spectrometry (LC-ESI/ MS) and tandem mass spectrometry (MS-MS). Four anthocyanins [cyanidin 3-glucoside, cyanidin 3-sambubioside, cyanidin 3–(2G −xylosylrutinoside) and cyanidin 3-rutinoside] were characterized in black raspberry samples by LC-ESI/MS-MS using both positive and negative ion analyses. Quantification of anthocyanins was conducted using ESI/MS-MS with selected reaction monitoring (SRM). Linear responses of several anthocyanins were determined during MS-MS analyses. Detection limits as low as 1 femtomol for most anthocyanins were obtained during ESI/MS-MS. Compared with other quantitative procedures such as high-performance liquid chromatography (HPLC) and ultraviolet/visible spectrophotometry, the current method provides an improved sensitive, specific technique for direct determination of intact anthocyanins. The developed methodology was successfully applied to analysis of trace levels of anthocyanins in human plasma and epithelial cells. 相似文献
104.
105.
Survival and Metabolic Activity of Listeria monocytogenes on Ready‐to‐Eat Roast Beef Stored at 4 °C 下载免费PDF全文
Johnathan W. Broady II Dong Han Jing Yuan Chao Liao Christy L. Bratcher Mark R. Lilies Elizabeth H. Schwartz Luxin Wang 《Journal of food science》2016,81(7):M1766-M1772
Three brands of commercial roast beef were purchased and artificially inoculated with a 5‐strain Listeria monocytogenes cocktail at 2 inoculation levels (approximately 3 and 6 Log CFU/g). Although all 3 brands contained sodium diacetate and sodium lactate, inoculated Listeria cocktail survived for 16 d in all 3 brands; significant increases in L. monocytogenes numbers were seen on inoculated Brand B roast beef on days 12 and 16. Numbers of L. monocytogenes increased to 4.14 Log CFU/g for the 3 Log CFU/g inoculation level and increased to 7.99 Log CFU/g for the 6 Log CFU/g inoculation level by day 16, with the pH values being 5.4 and 5.8 respectively. To measure the cell viability in potential biofilms formed, an Alamar blue assay was conducted. Brand B meat homogenate had the highest metabolic activities (P < 0.05). By comparing its metabolic activities to Brands A and C and the inoculated autoclaved meat homogenates, results indicated that the microflora present in Brand B may be the reason for high metabolic activities. Based on the denaturing gradient gel electrophoresis and the Shannon–Wiener diversity index analysis, the “Brand” factor significantly impacted the diversity index (P = 0.012) and Brand B had the highest microflora diversity (Shannon index 1.636 ± 0.011). Based on this study, results showed that antimicrobials cannot completely inhibit the growth of L. monocytogenes in ready‐to‐eat roast beef. Native microflora (both diversity and abundance), together with product formula, pH, antimicrobial concentrations, and storage conditions may all impact the survival and growth of L. monocytogenes. 相似文献
106.
DR Bielenberg CD Bucana R Sanchez CK Donawho ML Kripke IJ Fidler 《Canadian Metallurgical Quarterly》1998,111(5):864-872
We determined whether cutaneous angiogenesis induced by exposure of mice to ultraviolet-B (UVB) radiation is associated with an imbalance between positive and negative angiogenesis-regulating molecules. Unshaved C3H/HeN mice were exposed to a single dose (15 kJ per m2) of UVB. At various times, the mice were killed, and their external ears were processed for routine histology and immunohistochemistry. Antibodies against proliferating cell nuclear antigen and bromodeoxyuridine identified dividing cells. Antibodies against CD31/ PECAM-1 identified endothelial cells, and antibodies against basic fibroblast growth factor (bFGF), vascular endothelial growth factor/vascular permeability factor, and interferon-beta (IFN-beta) identified angiogenesis-regulating molecules. Epidermal hyperplasia was documented by 48 h and reached a maximum on day 7 after exposure to UVB. The expression of bFGF increased by 24 h, whereas the expression of IFN-beta decreased by 72 h after exposure to UVB. The expression of vascular endothelial growth factor/vascular permeability factor increased slightly after irradiation. The altered balance between bFGF and IFN-beta was associated with increased endothelial cell proliferation (bromodeoxyuridine + CD31 + cells) within existing blood vessels, leading to telangiectasia and new blood vessels. UV-induced epidermal hyperplasia and cutaneous angiogenesis were highest in IFN-alpha/beta receptor knockout mice. These results demonstrate that in response to UVB radiation, dividing keratinocytes produce a positive angiogenic molecule (bFGF) but not a negative angiogenic molecule (IFN-beta), and that this altered balance is associated with enhanced cutaneous angiogenesis. 相似文献
107.
108.
MH Boyle DR Offord D Campbell G Catlin P Goering E Lin YA Racine 《Canadian Metallurgical Quarterly》1996,41(9):549-558
OBJECTIVE: To describe the methodology of a province-wide, cross-sectional, epidemiologic study of psychiatric disorder among those aged 15 years and over living in household dwellings in Ontario. METHOD: Respondents for the survey were drawn from households (N = 13002) participating in a province-wide health survey. One person per household was selected, and 9953 (76.5%) participated. RESULTS: Participants and nonparticipants were similar to each other. An extensive array of data, including measures of psychiatric disorder classified using a revised version of the Composite International Diagnostic Interview (CIDI), are available for all respondents. CONCLUSIONS: The Ontario Health Supplement is contained in a public-use data file at the Ontario Ministry of Health and is available to investigators for study. A strong survey design, careful measurement, and acceptable levels of response provide the rationale for our inviting researchers to access and use the Ontario Health Supplement data base. 相似文献
109.
110.
Continuous non-invasive blood pressure (CNBP) measurements were compared to invasive radial artery pressure recordings in 26 patients with cardiac, vascular and/or pulmonary disease. Patients were studied during general anaesthesia (n = 6), regional anaesthesia (n = 10), or combined technique (n = 10) for abdominal or transurethral surgery. CNBP was obtained from a cuff placed around the upper arm and simultaneously compared to invasive pressure from the ipsilateral radial artery. A CNBP device (7001 Cortronic) used intermittent oscillometric measurement for calibration. Through a cuff continuously inflated to a pressure of 20 mmHg, a microprocessor-controlled electro-pneumatic acquisition system sensed displacements of the brachial artery wall. Amplified, digitally converted, filtered and transformed data were displayed as a continuous pulse pressure waveform and digital pressure values on the screen. The CNBP method functioned without disturbances before surgery in all patients. Intra-operative use of electrocautery or a spontaneous occurrence of warning on the screen repeatedly triggered oscillometric recalibration, hence CNBP measurements were discontinued in nine patients. Coefficients of correlation (r) of all invasive and CNBP pairs (n = 1111) were 0.68, 0.58 and 0.70 for systolic, diastolic, and mean blood pressures, respectively. Prediction errors (bias, mean +/- SD) were -13.6 +/- 22.5 mmHg (on average CNBP < invasive pressure) for systolic, +13.0 +/- 12.4 mmHg (CNBP > invasive pressure) for diastolic and +5.0 +/- 13.9 mmHg (CNBP > invasive pressure) for mean CNBP, as compared to radial artery pressure values. Absolute errors (precision) were 25.3 +/- 9.4 mmHg for systolic, 17.4 +/- 4.5 mmHg for diastolic, and 13.9 +/- 4.6 mmHg for mean CNBP. During anaesthesia induction (n = 672) the difference between consecutive measurements (trend of pressure changes) with invasive and CNBP method exceeded 20 mmHg in 90 (13.3%) instances for systolic, in 33 (4.9%) instances for diastolic, and in 45 (6.6%) instances for mean blood pressure. In conclusion, the CNBP method by brachial artery wall displacement failed to measure the blood pressure reliably and to display the trend of pressure changes correctly during anaesthesia induction. In its present form this CNBP method should not replace invasive blood pressure monitoring in high-risk patients neither for anaesthesia induction nor during non-thoracic surgical procedures. 相似文献