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1.
The authors investigated subgroup differences on a multiple-choice and constructed-response test of scholastic achievement in a sample of 197 African American and 258 White test takers. Although both groups had lower mean scores on the constructed-response test, the results showed a 39% reduction in subgroup differences compared with the multiple-choice test. The results demonstrate that the lower subgroup differences were explained by more favorable test perceptions for African Americans on the constructed-response test. In addition, the two test formats displayed comparable levels of criterion-related validity. The results suggest that the constructed-response test format may be a viable alternative to the traditional multiple-choice test format in efforts to simultaneously use valid predictors of performance and minimize subgroup differences in high-stakes testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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OBJECTIVE: To determine factors important to clinical success in micromanipulation-assisted in vitro fertilization (IVF). DESIGN: Procedures invoked in two separate series of micromanipulation-assisted IVF cycles, one unsuccessful (series I) and the other successful (series II), were compared in an effort to identify changes that led to clinical success. SETTING: University-based IVF clinic. PATIENTS: In both IVF series involving micromanipulation, patients consisted of infertile couples who fit any of five categories of male-factor related infertility. The female patients underwent controlled hyperstimulation for oocyte retrieval and the oocytes were inseminated normally or were subjected either to partial zona dissection or subzonal sperm insertion to assist fertilization. Results in all groups were compared between the two patient series. RESULTS: In the successful series II, a noticeable improvement in fertilization rate and embryo quality was observed compared with series I. A significant increase in the percentage of patients reaching embryo transfer, the pregnancy rate per transfer, and the pregnancy rate per retrieval were noted in series II; a 25% ongoing pregnancy rate per retrieval was observed overall in this successful group, with "ongoing" defined as manifestation of at least a fetal sac on ultrasound with no detectable problems. Patients with a mixed transfer of embryos derived from manipulated and normally inseminated oocytes had a 75% rate of pregnancy per transfer in series II. Differences between the two series could not be attributed to patient selection or biases in selection of oocytes relegated to micromanipulation. However, oocyte handling, micromanipulation, and culture protocols differed significantly between the two series in that temperature and pH of oocytes was better controlled, and micromanipulation time was minimized in series II. CONCLUSION: Success in micromanipulation depends on maintenance of the oocyte in a stable and supportive environment throughout the micromanipulation procedure. It is also important to minimize trauma to the eggs by performing micromanipulation rapidly and with minimal distortion of the egg. Patients with a poor fertilization rate in standard IVF may experience a substantial increase in the likelihood of pregnancy when micromanipulation-assisted fertilization is performed on some eggs.  相似文献   

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Iron deficiency anemia is associated with lower plasma thyroid hormone concentrations in rodents and, in some studies, in humans. The objective of this project was to determine if plasma triiodothyronine (T3) and thyroxine (T4) kinetics were affected by iron deficiency. Studies were done at a near-thermoneutral temperature (30 degrees C), and a cool environmental temperature (15 degrees C), to determine plasma T3 and T4 kinetics as a function of dietary iron intake and environmental need for the hormones. Weanling male Sprague-Dawley rats were fed either a low Fe diet [iron-deficient group (ID), <5 microg/g Fe] or a control diet [control group (CN), 35 microg/g Fe] at each temperature for 7 wk before the tracer kinetic studies. An additional ID group receiving exogenous thyroid hormone replacement was also used at the cooler temperature. For T4, the disposal rate was >60% lower (89 +/- 6 vs. 256 +/- 53 pmol/h, P < 0.001) in ID rats than in controls at 30 degrees C, and approximately 40% lower (192 +/- 27 vs. 372 +/- 26 pmol/h, P < 0.01) in ID rats at 15 degrees C. Exogenous T4 replacement in a cohort of ID rats at 15 degrees C normalized the T4 concentration and the disposal rate. For T3, the disposal rate was significantly lower in ID rats in a cool environment (92 +/- 11 vs. 129 +/- 11 pmol/h, P < 0.01); thyroxine replacement again normalized the T3 disposal rate (126 +/- 12 pmol/h). Neither liver nor brown fat thyroxine 5'-deiodinase activities were sufficiently different to explain the lower T3 disposal rates in iron deficiency. Thus, plasma thyroid hormone kinetics in iron deficiency anemia are corrected by simply providing more thyroxine. This suggests a central regulatory defect as the primary lesion and not peripheral alterations.  相似文献   

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The number of ethnic minority persons in the United States is increasing faster than that of the Caucasian population. This means that nurses will be caring for an increasingly diverse patient pool. Ethnic differences have been discovered to play a role in the efficacy of psychoactive medication. These differences result from a number of biological as well as non biological factors. Nurses have a professional obligation to be aware and sensitive to differential response to treatment.  相似文献   

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In the decade since the clinical arrival of laparoscopic cholecystectomy, there have been gratifying improvements in imaging technology and instrumentation, and innovative techniques have evolved. Laboratory-simulator devices are available for basic skills exercises and can at least reasonably mimic the appearance of the gallbladder and some other organs or anatomic regions. Unfortunately, there is no satisfactory method to practice dealing with certain structural abnormalities or disease processes. Because of that, some operations will be particularly difficult and the outcomes will be favorable only with careful planning and capable execution. The experiences and skill level of the surgeon can be enhanced by appropriate mental preparation. As a result, the surgeon will have the opportunity to accomplish the task, both laparoscopically and safely, under circumstances that initially were thought to be inappropriate or impossible for laparoscopy.  相似文献   

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高等教育的发展使大学形成了一个庞大的市场,商业贿赂也侵蚀到了大学校园。本文分析了高校商业贿赂的性质、特征,危害和原因,并提出了防治对策。  相似文献   

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A case of acute pancreatitis following gastrostomy feeding tube insertion is presented. This is a rare and fatal complication, which has not been described before. The role of the gastrostomy catheter and total enteral nutrition in the causation of acute pancreatitis is discussed. Pathologists and clinicians should be aware of this disastrous and potentially avoidable condition.  相似文献   

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BACKGROUND: When President Abraham Lincoln was shot in the back of the head at Ford's Theater in Washington, D.C., on April 14, 1865, he was immediately rendered unconscious and apneic. Doctor Charles A. Leale, an Army surgeon, who had special training in the care of brain injuries, rushed to Lincoln's assistance. When Doctor Leale probed the wound in Lincoln's thickened scalp, feeling for the bullet, he dislodged a blood clot, and Lincoln began to breathe again. However, Lincoln progressively deteriorated and died at 7:22 AM on April 15, 1865. During the postmortem examination of Lincoln's body, numerous secondary missiles of bone and metal were found in the track of pultaceous brain tissue, extending completely through the brain to the front of the skull. In February 1995, an article in a popular magazine alleged that Doctor Leale had caused further (fatal) damage to Lincoln's brain by thrusting his finger into the brain through the bullet hole. The article alleged (wrongly) that most bullet wounds of the brain incurred in Civil War times were not fatal. STUDY DESIGN: The following study demonstrates that it is impossible to introduce even the tip of the little finger through a hole in the skull resulting from a .41-caliber bullet fired from a derringer. In our study, a .41-caliber derringer was used to fire bullets into numerous fresh skulls; the bullet holes all had razor-sharp edges and were much too small to accommodate a fingertip. RESULTS: Thus, the allegation that President Lincoln's brain was damaged further because Doctor Leale thrust his finger through the bullet hole into the brain parenchyma is not valid. In this study, experimental data are presented to demonstrate the foregoing point. CONCLUSIONS: The wound made by John Wilkes Booth's derringer ball in Lincoln's brain was devastating; it was clearly the cause of his death. Good Samaritan surgeon Leale has been falsely accused of contributing to Lincoln's death.  相似文献   

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1. The risk of chemical dependency in women includes a chaotic family of origin, victimization, and low self-esteem. 2. Women with substance abuse disorders often suffer from a co-morbid depression, which is a threat to relapse. 3. Nursing and nursing education must develop strategies to minimize the risks associated with substance abuse disorders.  相似文献   

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OBJECTIVE: To evaluate risk factors for fatal neonatal sepsis. DESIGN: Prospective study. SETTING: Referral neonatal unit of a teaching hospital. SUBJECTS: 171 neonates admitted with sepsis. METHODS: Clinical examination and investigations on the day of admission were recorded and the neonates followed up to determine the final outcome. RESULTS: The overall fatality was 48.5%. In the univariate analysis, the factors significantly associated with death were weight, gestational age, age at onset of sepsis, hypothermia, requirement of IPPV, presence of refractory septic shock, neutropenia, metabolic acidosis and raised prothrombin time. However, in the multivariate analysis, only neutropenia, metabolic acidosis, increased prothrombin time and refractory septic shock retained their significance. The adjusted odd's ratio (95% confidence interval) were 0.095 (0.04 = 0.22), 1.14 (1.04-1.25), 1.04 (1.002-1.08) and 11.82 (5.47-69.40), respectively. CONCLUSION: Even in a setting with high fatality rates, high risk of mortality in neonatal sepsis can be identified and targeted for intensive intervention.  相似文献   

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From 1970 to 1992 a total of 63 patients underwent operation for ampullary tumor: 40 pancreatoduodenectomies (PDs), 3 total PDs, 8 ampullectomies, and 12 bypass or exploratory laparotomies. The resectability rate was 68%. There were 9 benign tumors, 1 anaplastic tumor, and 53 adenocarcinomas. According to Martin's classification, there were 7 stage I, 11 stage II, 14 stage III, and 21 stage IV tumors. All patients with stage I, II, and III tumors underwent resection. Patients with stage IV tumors had either resection (n = 11) or bypass (n = 10). The mean duration of hospital stay was 20.6 days. Operative mortality was 12.7% for the whole series and 7.5% after PD (2.5% for the last 10 years). Overall survival was 40% at 5 years (85% for stage I, 65% for stage II, 44% for stage III, and 8% for stage IV). Survival was better for stages I, II, and III after PD than after ampullectomy. For stage IV patients survival was 70% after PD versus 20% after bypass at 1 year and 25% versus 0% after 2 years. In our opinion, PD should be proposed even for benign lesions because two of our patients had to undergo repeat operation (PD) 4 and 22 years later, respectively, for stage IV disease. PD is our choice for all tumors of the ampulla.  相似文献   

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The morphology and function of the liver was studied by pathomorphological, gas chromatographic, and histochemical analysis in 108 forensic medical expert evaluations of alcohol poisoning, coronary disease, alcohol cardiomyopathy, craniocerebral injury, and mechanical asphyxia. Ethanol concentrations in the blood collected from various parts of the venous system varied: in 69% of cases the level of ethanol was higher in the inferior vena cava than in the portal vein. Histochemical analysis of ethanol-oxidizing enzymatic systems together with pathomorphological findings and alcohol measurements in various parts of the venous system help assess the morphology and function of the liver, define the thanatogenesis, and draw objective expert conclusion on the cause of death.  相似文献   

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The central tunnel of the eight-bladed beta-propeller domain of cytochrome cd1 (nitrite reductase) is seen, from a 1.28 A resolution structure, to contain hydrogen donors and acceptors that are satisfied by interaction either with water or the d1 haem. The d1 haem, although bound by an extensive network of hydrogen bonds, is not distorted in its binding pocket and is confirmed to have exactly the dioxoisobacteriochlorin structure proposed from chemical studies. A biological rationale is advanced for the undistorted structure of the d1 haem and the large number of hydrogen bonds it makes. The beta-propeller domain can be closely superimposed on that of methanol dehydrogenase despite the enzymes sharing no common sequence motifs and using a different set of interactions to "Velcro" close the propeller. The sequence and likely structural relationships between cytochrome cd1 or methanol dehydrogenase and other predicted eight-bladed beta-propeller domains in proteins, such as the pyrolloquinoline quinone-dependent alcohol dehydrogenase, are discussed and compared with other propeller proteins. From sequencing the nirS gene of Thiosphaera pantotropha, it is established that the amino acid sequence deduced previously in part from X-ray diffraction data at lower resolution was largely correct, as was the proposal that eight N-terminal amino acid residues were not seen in the structure. The unusual haem iron environments in both the c-type cytochrome domain, with His/His coordination, and the d1-type cytochrome domain with Tyr/His coordination are related to the functions of the redox centres.  相似文献   

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Behavioral and neural correlates of latent inhibition (LI) during eyeblink conditioning were studied in 2 experiments. In Experiment 1, rabbits (Oryctolagus cuniculus) were conditioned after 8 days of tone conditioned stimulus (CS) presentations or 8 days of context-alone experience. LI was seen in the CS-preexposed rabbits when a relatively intense (5 psi) airpuff unconditioned stimulus was paired with the CS. In Experiment 2, rabbits were given 0, 4, or 8 days of CS preexposures or context-alone experience. Hippocampal activity was monitored from the 8-day CS- or context-exposure rabbits. The LI effect was seen only in rabbits given 4 days of CS preexposure, thus suggesting that LI depended largely on the rate of acquisition in the context-preexposed control group. The neural recordings showed that the hippocampus was sensitive to the relative novelty of the stimuli and the overall context, regardless of whether exposure to stimuli and context promoted LI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Respiratory aspiration is a serious potential complication of glyphosate-surfactant herbicide intoxication. From October 1, 1992 to June 30, 1996, we performed laryngeal evaluations in 53 cases to investigate the possible pathophysiological mechanism of glyphosate intoxication. There were 36 cases with significant laryngeal injury. The blood WBC count were significantly higher and the hospital stays were significantly longer in patients with laryngeal injury, when compared with patients with no laryngeal injury (Student t-test, P < 0.005). Laryngeal injury was strongly correlated with aspiration pneumonitis (mean 2 = 4.449, P < 0.05). We concluded that laryngeal injury may be the major cause of aspiration that leads to some degree of morbidity and mortality, following concentrated glyphosate-surfactant herbicide intoxication. Laryngeal survey may be indicated in cases of glyphosate-surfactant intoxication, to evaluate the severity of mucosal injury, and to apply adequate supportive management as early as possible to prevent from aspiration complications and even mortality.  相似文献   

18.
A case of overdosage with closantel, a salicynalide derivative, in a dog is described. The dog received 6 times the recommended dosage. Closantel induced optic neuritis, retinal degeneration, partial deafness, hepatotoxicosis and myopathy. Only the blindness was irreversible. The therapy included albumin administration to reduce the acute toxicity of closantel.  相似文献   

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Uptake and efflux of colchicine and vinblastine, whose effects are related to their high-affinity binding to tubulin, were studied in the immortalized rat brain microvessel endothelial cell line RBE4. At 10 nM extracellular drug concentration, uptake equilibrium was approached at 45 hr for colchicine, but at only 3.5 hr for vinblastine. After 1 hr preincubation with 200 nM colchicine or vinblastine, drug efflux fitted biexponential kinetics with an initial fast phase (half-life = 2.2 min and 9.6 min, respectively) and a later slow phase (half-life = 3.6 hr and 1.8 hr, respectively). After 6 hr preincubation with 200 nM colchicine, only the slow phase (half-life = 3.6 hr) could be observed. The colchicine and vinblastine uptake rate was increased by cyclosporin A, an inhibitor of the drug efflux pump P-glycoprotein, which is expressed at the blood-brain barrier. Whereas cyclosporin A decreased vinblastine efflux, its effect on colchicine efflux was apparent after only 13 hr washout and was associated with the re-uptake by cells of colchicine molecules. Differences in uptake kinetics of colchicine and vinblastine could be related to differences in their lipid solubility, and mainly in their binding affinities to tubulin. Differences in efflux kinetics could in addition be explained by the involvement of P-glycoprotein in the efflux of vinblastine, whereas efflux of colchicine was not influenced by this pump. Indeed, binding of colchicine to tubulin would imply that most intracellular colchicine may be inaccessible to P-glycoprotein. In the case of a cytotoxic drug such as colchicine, which is tightly bound to intracellular receptors, the role of P-glycoprotein within the blood-brain barrier would be more to protect the brain against entry of this drug than to detoxify the brain by its extraction.  相似文献   

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