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排序方式: 共有245条查询结果,搜索用时 15 毫秒
1.
2.
Lactate clearance and survival following injury 总被引:1,自引:0,他引:1
D Abramson TM Scalea R Hitchcock SZ Trooskin SM Henry J Greenspan 《Canadian Metallurgical Quarterly》1993,35(4):584-8; discussion 588-9
Previous reports cite optimization of O2 delivery (DO2) to 660 mL/min/m2, O2 consumption (VO2) to 170 mL/min/m2, and cardiac index (CI) of 4.5 L/min as predicting survival. We prospectively evaluated 76 consecutive patients with multiple trauma admitted directly to the ICU from the operating room or emergency department. Patients had serum lactate levels and oxygen transport measured on ICU admission and at 8, 16, 24, 36, and 48 hours. Patients were analyzed with respect to survival (S) versus nonsurvival (NS), lactate clearance to normal (< or = 2 mmol/L) by 24 and 48 hours, hemodynamic optimization as defined above, as well as Injury Severity Score (ISS), ICU stay (LOS), and admission blood pressure. All patients achieved non-flow-dependent VO2. There was no difference in CI, DO2, VO2, or ISS when S was compared with NS. All 27 patients whose lactate level normalized in 24 hours survived. If lactate levels cleared to normal between 24 and 48 hours, the survival rate was 75%. Only 3 of the 22 patients who did not clear their lactate level to normal by 48 hours survived. Ten of the 25 nonsurvivors (40%) achieved the above arbitrary optimization criteria. Fifteen of the survivors never achieved any of these criteria. Optimization alone does not predict survival. However, the time needed to normalize serum lactate levels is an important prognostic factor for survival in severely injured patients. 相似文献
3.
The pharmacokinetic and pharmacodynamic effects of vaginal rings releasing levonorgestrel (L-NOG) at an initial rate of 27 micrograms/24 h were studied in a group of 12 normally menstruating women during 90 days of continuous use (i.e., during three 30-day treatment segments). Blood samples were drawn immediately before insertion, 15 and 30 min, as well as 1, 2, 4, 8, 12 and 24 h after insertion of the rings, and thereafter three times weekly throughout the study for the analysis of L-NOG, estradiol, progesterone and sex hormone-binding globulin (SHBG). Endometrial biopsies were obtained for a morphometric analysis in a pre-treatment (control) cycle and in the 6th and 10th weeks of treatment. The peak of average L-NOG levels was reached within two hours after the insertion of rings. Until 24 h after insertion, the levels did not change significantly. Thereafter, a decrease at a rate of 0.2% per day was initiated. The L-NOG and SHBG levels were highly correlated. This was seen for both the pre-treatment SHBG vs L-NOG (r = 0.96) and the treatment SHBG vs L-NOG levels (r = 0.92). There was a significant (p < 0.001) decrease of SHBG levels due to treatment. During the total of 36 treatment segments, a normal ovarian function was seen in 47% of the segments. The women were anovulatory and had an inadequate lutal function in 28% and 25% of segments, respectively. No correlation between the L-NOG levels and ovarian reaction to treatment was found. The use of L-NOG induced significant changes in the endometrium; the number of glands/mm2 decreased after 6 (p < 0.02) and 10 weeks of use (p < 0.01). Also, the diameter of glands and the occurrence of vacuolated cells decreased significantly (p < 0.02 and p < 0.005, respectively). None of the endometrial parameters or dating was correlated with the ovarian reaction to treatment, indicating independent endometrial effects of L-NOG. 相似文献
4.
SZ Zhou S Cooper LY Kang L Ruggieri S Heimfeld A Srivastava HE Broxmeyer 《Canadian Metallurgical Quarterly》1994,179(6):1867-1875
Recombinant adeno-associated virus 2 (AAV) virions were constructed containing a gene for resistance to neomycin (neoR), under the control of either the herpesvirus thymidine kinase (TK) gene promoter (vTK-Neo), or the human parvovirus B19 p6 promoter (vB19-Neo), as well as those containing an upstream erythroid cell-specific enhancer (HS-2) from the locus control region of the human beta-globin gene cluster (vHS2-TK-Neo; vHS2-B19-Neo). These recombinant virions were used to infect either low density or highly enriched populations of CD34+ cells isolated from human umbilical cord blood. In clonogenic assays initiated with cells infected with the different recombinant AAV-Neo virions, equivalent high frequency transduction of the neoR gene into slow-cycling multipotential, erythroid, and granulocyte/macrophage (GM) progenitor cells, including those with high proliferative potential, was obtained without prestimulation with growth factors, indicating that these immature and mature hematopoietic progenitor cells were susceptible to infection by the recombinant AAV virions. Successful transduction did not require and was not enhanced by prestimulation of these cell populations with cytokines. The functional activity of the transduced neo gene was evident by the development of resistance to the drug G418, a neomycin analogue. Individual high and low proliferative colony-forming unit (CFU)-GM, burst-forming unit-erythroid, and CFU-granulocyte erythroid macrophage megakaryocyte colonies from mock-infected, or the recombinant virus-infected cultures were subjected to polymerase chain reaction analysis using a neo-specific synthetic oligonucleotide primer pair. A 276-bp DNA fragment that hybridized with a neo-specific DNA probe on Southern blots was only detected in those colonies cloned from the recombinant virus-infected cells, indicating stable integration of the transduced neo gene. These studies suggest that parvovirus-based vectors may prove to be a useful alternative to the more commonly used retroviral vectors for high efficiency gene transfer into slow or noncycling primitive hematopoietic progenitor cells, without the need for growth factor stimulation, which could potentially lead to differentiation of these cells before transplantation. 相似文献
5.
BK Park ES Cho JD Lee C Oh MS Lee SZ Kim SH Kim KW Cho 《Canadian Metallurgical Quarterly》1998,43(8):611-618
The effect of a naturally occurring plant phenolic constituent (the acylphloroglucinol derivative, jensenone, derived from Eucalyptus jensenii) on the food intake of two folivorous marsupials, the common ringtail (Pseudocheirus peregrinus) and the common brushtail possum (Trichosurus vulpecula) was studied. When fed diets containing varying concentrations of jensenone, both species regulated their intake of jensenone so as not to exceed a ceiling intake. This ceiling was about twice as high for common ringtails as for common brushtails from northern Australia. Southern populations of common ringtails showed greatly reduced capacities to tolerate jensenone. When common brushtails were injected (0.5 mg.kg-0.75 body mass) with ondansetron (a selective antagonist of serotonin 5HT3 receptors), they ate significantly more jensenone than animals injected with physiological saline. The same pattern was observed when common ringtails were fed diets containing both jensenone and ondansetron (0.0035 mg.g-1 wet mass of diet). Ondansetron injection had no effect on food intake when the food did not contain jensenone while the addition of higher doses of ondansetron to diets of common ringtails very slightly reduced food intakes of a non-jensenone diet. When common brushtails were given 50 mg of jensenone by gastric lavage, their average subsequent intake of dietary jensenone matched the difference between the daily threshold and the dose given, although the response of individuals was highly variable. Lavage with water alone had no effect on subsequent jensenone intake compared with the pre-dose period. We interpret these results as evidence that the antifeedant effects of jensenone and related compounds are partly mediated by serotonin action on 5HT3 receptors most likely via "nausea" to condition a food aversion. 相似文献
6.
Tabu search for attribute reduction in rough set theory 总被引:2,自引:0,他引:2
Abdel-Rahman Hedar Jue Wang Masao Fukushima 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(9):909-918
In this paper, we consider a memory-based heuristic of tabu search to solve the attribute reduction problem in rough set theory.
The proposed method, called tabu search attribute reduction (TSAR), is a high-level TS with long-term memory. Therefore, TSAR
invokes diversification and intensification search schemes besides the TS neighborhood search methodology. TSAR shows promising
and competitive performance compared with some other CI tools in terms of solution qualities. Moreover, TSAR shows a superior
performance in saving the computational costs. 相似文献
7.
Ehab Abdel-Rahman Amr Shaarawi 《Journal of Materials Science: Materials in Electronics》2009,20(Z1):153-158
The properties of one-dimensional periodic and quasiperiodic photonic crystals with a defect layer have been investigated.
Transfer matrix method (TMM) has been used throughout this study. For periodic photonic crystals, results demonstrate the
independence of the defect mode frequency on the defect layer while the defect mode transmission coefficient varies with the
position of the defect layer position. On the other hand, defect mode frequency is not that responsive to the index of refraction
of the defect layer. The quality factor of the defect mode has been studied as a function of the defect layer position as
well as its thickness. For quasiperiodic photonic crystals, the frequency of the defect mode is very sensitive to the defect
layer position as well as its thickness. An enhancement of the quality factor of the defect mode has been observed. This study
may be valuable in designing optical devices and it may also provide a more accurate method to measure the index of refraction. 相似文献
8.
Methionine-enriched protein was produced from an enzymatically pre-hydrolyzed milk protein using an enzymatic peptide modification (EPM) method with α-chymotrypsin as catalyst. Methionine of the product was twice as high as that of the substrate protein. The incorporated methionine formed a covalent bond with the peptide chain in the product protein. The change in the number of peptide bonds was monitored by the degree of hydrolysis (DH). The slight change of the DH values revealed that a portion of the free amino acids was bound to the peptide chains during the reaction and that transpeptidation was the main process during the EPM treatment. The location of the newly incorporated amino acids was determined by identification of the terminal amino acids. The covalently bound methionine was located in C- and N-terminal positions in a ratio of 3:1. 相似文献
9.
L Scorolli E Martini SZ Scalinci LG Scorolli R Meduri 《Canadian Metallurgical Quarterly》1996,22(9):1245-1246
We report two cases of capsular bag contraction that occurred within 1 month after continuous curvilinear capsulorhexis, phacoemulsification, and intraocular lens implantation. Neither patient had a known risk for this complication. Both patients had a neodymium:YAG laser anterior capsulotomy, which disrupted the capsulorhexis margin and led to prompt capsular bag distension. 相似文献
10.
Elfatih M. Abdel-Rahman Fethi B. Ahmed Maurits van den Berg Mike J. Way 《International journal of remote sensing》2013,34(15):4199-4216
Sugarcane thrips was detected in South African sugarcane in 2004. Since then it has become widespread in South Africa. The South African Sugarcane Research Institute (SASRI) conducts field surveys to monitor this pest, but this is time intensive and costly. As a first step towards evaluation of remote sensing for thrips monitoring, a preliminary experiment and analysis at leaf level were conducted using a handheld field spectroradiometer covering the 350 to 2500 nm range of the electromagnetic spectrum to detect sugarcane thrips damage. Reflectance spectra of sugarcane leaves with different levels of thrips damage, from two popular varieties (N19 and N12), were measured and statistically analysed using one-way analysis of variance, sensitivity analysis and canonical discriminant analysis. The results of the analyses showed that there were significant differences in spectral reflectance and derived variables used in the study at the different levels of damage. The red edge region of the visible portion gave the highest significant differences and levels of separability among the damage classes. It is hypothesized that this might be associated with chlorophyll and nitrogen deficiencies induced by thrips. 相似文献