Estimating local mean signal strength of indoor multipathpropagation

We explore techniques for the measurement of local mean signal strength at 900 MHz and 2 GHz. In particular, we characterize the impact of transmitter and receiver antenna rotation on the estimated local mean. Then, we explore the collection of high resolution data while moving along a linear trajectory and using linear averaging techniques to estimate the local mean. With this information, the best measurement techniques can be chosen depending on the required speed versus accuracy tradeoff. Finally, we use a ray tracing propagation model to evaluate different methods of calculating the local mean signal strength for indoor environments     

Snowboard traumatology: an epidemiological study

OBJECTIVE: To estimate the frequency of perioperative morbidities in patients who underwent anesthesia and a surgical procedure with no preoperative laboratory testing. MATERIAL AND METHODS: We conducted an electronic database search of medical records of 56,119 patients who underwent surgical or diagnostic procedures and anesthesia at Mayo Clinic Rochester in 1994 and found 5,120 who had no laboratory tests done within 90 days before the procedure. From this group, we randomly selected 1,044 patients (87 from each month) to document the absence of preoperative tests, the presence of preexisting disease (by organ system), the type of anesthetic agent, and the outcomes and tests intraoperatively and postoperatively. RESULTS: The 1,044 patients ranged in age from 0 to 95 years (median age, 21). No deaths or major perioperative morbidities occurred (0.0%; exact 95% confidence interval, 0.00 to 0.35%). Although 10 patients underwent blood typing and screening for antibodies immediately preoperatively, no blood transfusions were necessary. Intraoperatively, 17 laboratory tests and 1 electrocardiogram were obtained, and 3 results were abnormal. Postoperatively, 42 blood tests and 2 electrocardiographic procedures were performed. Five of the 42 blood tests showed abnormal results (hemoglobin levels in 3, serum sodium in 1, and arterial blood gases in 1). One electrocardiogram showed normal findings, and the other revealed normal results except for premature ventricular contractions. No laboratory test done intraoperatively or postoperatively was found to change surgical or medical management substantially. One patient who had unanticipated blood loss during an outpatient procedure was admitted to the hospital for observation. CONCLUSION: All 1,044 patients, 97% of whom were relatively healthy, with no recent laboratory testing safely underwent anesthesia and an operation. We conclude that patients who have been assessed by history and physical examination and determined to have no preoperative indication for laboratory tests can safely undergo anesthesia and operation with tests obtained only as indicated intraoperatively and post-operatively. Current anesthetic and medical practices rapidly identify perioperative indications for laboratory evaluation as they arise.     

Electronic transport in a type-II GaInAsSb/p-InAs heterojunction with different doping levels of the solid solution

Galvanomagnetic phenomena and photoconductivity in broken-gap type-II GaInAsSb/p-InAs heterojunctions with different levels of doping of the solid solution with donor (Te) or acceptor (Zn) impurities have been investigated. It has been determined that in such structures an electronic channel, which determines the galvanomagnetic effects in a wide range of doping levels, is present at the heterojunction. A sharp decrease of the Hall mobility was observed in the experimental heterostructures with a high level of doping of the epitaxial layer with an acceptor impurity. The observed effect is due to exhaustion of the electronic channel as a result of carrier localization in potential wells at the heterojunction. Fiz. Tekh. Poluprovodn. 31, 897–901 (August 1997)     

No involvement of APC gene mutations in ulcerative colitis-associated rat colon carcinogenesis induced by 1-hydroxyanthraquinone and methylazoxymethanol acetate

In 1992, 1531 women aging 25-45 years from 5 urban and rural regions were interviewed about infertility and subfecundity within the German part of a study by the European community. 1248 of them had a positive reproductive history with 3018 pregnancies. 400 (= 13.25%) occurred during contraception. This affected 296 women (= 19.6% of all women). Smoking seems to have a promotion effect. The risk of ectopic pregnancies seems to be higher in contraceptive users. The highest fetal loss was found in women using an IUD. There were no differences in the course and outcome of pregnancy between users and nonusers of contraceptives. About 40% of the women in the corresponding group reported an irregular application of the contraceptive technique.     

Color image retrieval based on hidden Markov models

In this correspondence, a new approach to retrieving images from a color image database is proposed. Each image in the database is represented by a two-dimensional pseudo-hidden Markov model (2-D PHMM), which characterizes the chromatic and spatial information about the image. In addition, a flexible pictorial querying method is used, by which users can paint the rough content of the desired images in a query picture. Image matching is achieved by comparing the query picture with each 2-D PHMM in the database. Experimental results show that the proposed approach is indeed effective.     

Development of severe secondary hypertension in a patient with systemic entomophthoromycosis

The sudden onset of hypertension mandates investigation for secondary causes. We report the case of a young man with a very rare systemic fungal disease that included massive unilateral perirenal adenopathy. Treatment was associated with the abrupt onset of severe hypertension. Imaging studies suggested progressive constriction of one kidney with treatment, presumably as a result of healing adenopathy. We suggest that this case is a new example of hypertension secondary to constrictive perinephritis (Page kidney).     

Cathepsin E expression by normal and premalignant cervical epithelium

We have investigated the expression of the aspartic proteinase cathepsin E and HLA-DR and the presence of HPV16 in normal squamous epithelium (n = 8) and low-grade (n = 21) and high-grade (n = 14) intraepithelial squamous lesions of the uterine cervix. Immunohistochemistry of cervical biopsies revealed that up-regulation of cathepsin E expression was related to increasing severity of the cervical intraepithelial neoplasia (CIN). Up-regulation of protein was associated with increased message as assessed by in situ hybridization. Langerhans cells and the majority of koilocytes did not express detectable cathepsin E levels. Although there was also an up-regulation of HLA-DR expression by cervical keratinocytes in cervical intraepithelial neoplasia lesions, as determined by immunohistochemistry, no significant correlation was found between HLA-DR and cathepsin E expression in these lesions; neither was expression of cathepsin E correlated to the presence of HPV16, detected by polymerase chain reaction. The expression of cathepsin E, an aspartic proteinase that is reported to play a role in antigen processing for presentation by class II major histocompatibility complex molecules, is associated with cellular dedifferentiation in cervical intraepithelial neoplasia.     

8-epi PGF2 alpha generation during coronary reperfusion. A potential quantitative marker of oxidant stress in vivo

BACKGROUND: Myocardial reperfusion is believed to be associated with free radical injury. However, indexes of oxidative stress in vivo have been limited by their poor specificity and sensitivity. Isoprostanes are stable products of arachidonic acid formed in a nonenzymatic, free radical-catalyzed manner. We have developed a sensitive and specific assay for one of these compounds, 8-epi prostaglandin (PG) F2 alpha. METHODS AND RESULTS: To address its utility as an index of oxidative stress during coronary reperfusion, we measured urinary levels by gas chromatography/mass spectrometry in a canine model of coronary thrombolysis, in patients with acute myocardial infarction treated with thrombolytic therapy, and in patients after elective coronary artery bypass surgery. Urinary 8-epi PGF2 alpha was unchanged after circumflex artery occlusion in a canine model of coronary thrombolysis (n = 13; 437.2 +/- 56.4 versus 432.7 +/- 55.2 pmol/mmol creatinine) but increased significantly (P < .05) immediately after reperfusion (553.8 +/- 64.7 pmol/mmol). Urinary levels were increased (P < .001) in patients (n = 12) with acute myocardial infarction given lytic therapy (265.8 +/- 40.8 pmol/mmol) compared with age-matched control subjects (n = 20; 91.5 +/- 11.8 pmol/mmol) and patients with stable coronary disease (n = 20; 95.7 +/- 6.3 pmol/mmol). Preoperative levels rose from 113.2 +/- 11.8 to 248.2 +/- 86.3 pmol/mmol at 30 minutes into revascularization to 332.2 +/- 82.6 pmol/mmol by 15 minutes after global myocardial reperfusion (P < .05) and dropped to 181.2 +/- 50.4 pmol/mmol at 30 minutes and 120.2 +/- 9.9 pmol/mmol at 24 hours after bypass surgery (n = 5). Corresponding changes in spin adduct formation, found with electron paramagnetic resonance, were noted in 2 patients. CONCLUSIONS: These data support the hypothesis that free radical generation occurs during myocardial reperfusion. Measurement of isoprostane production may serve as a noninvasive index of oxidative stress.     

35S]Guanosine-5''-O-(3-thio)triphosphate binding as a measure of efficacy at human recombinant dopamine D4.4 receptors: actions of antiparkinsonian and antipsychotic agents

Great progress has been made in the last 10 years in the understanding of the various types of viral hepatitis, and new viruses, concepts, therapies, preventive measures, and control strategies have been recognized. Even more agents, vaccines, and drugs will be discovered or developed in the future, and pediatricians increasingly will be expected to provide guidance to patients and to the community on the importance and use of these new tools.     

Effect of shigella enterotoxin 1 (ShET1) on rabbit intestine in vitro and in vivo

The purpose of this study was to identify the optimal knot construction for interrupted dermal sutures. A synthetic braided absorbable suture, sizes 3-0 and 5-0, was selected for this evaluation. With reproducible mechanical performance tests, we determined that the construction of secure knots without ears required one additional throw as compared with secure knots with 3-mm ears. The direction of applied tension did not alter knot security, with the exception of granny knots, which required an extra throw when tension was applied parallel to the suture loop. Because interrupted dermal knot construction is accomplished without knot ears and with an applied tension parallel to the wound, one additional throw must be added to the knot to ensure knot security.