cssi/SciSciGPT-SciSciNet huggingface dataset:
Real-Time Monitoring of High-Intensity Focused Ultrasound Treatment Using Axial Strain and Axial-Shear Strain Elastograms

Axial strain elastograms (ASEs) have been found to help visualize sonographically invisible thermal lesions. However, in most studies involving high-intensity focused ultrasound (HIFU)-induced thermal lesions, elastography imaging was performed separately later, after the lesion was formed. In this article, the feasibility of monitoring, in real time, tissue elasticity variation during HIFU treatment and immediately thereafter is explored using quasi-static elastography. Further, in addition to ASEs, we also explore the use of simultaneously acquired axial-shear strain elastograms (ASSEs) for HIFU lesion visualization. Experiments were performed on commercial porcine liver samples in vitro. The HIFU experiments were conducted at two applied acoustic power settings, 35 and 20 W. The experimental setup allowed us to interrupt the HIFU pulse momentarily several different times during treatment to perform elastographic compression and data acquisition. At the end of the experiments, the samples were cut along the imaging plane and photographed to compare size and location of the formed lesion with those visualized on ASEs and ASSEs. Single-lesion and multiple-lesion experiments were performed to assess the contribution of ASEs and ASSEs to lesion visualization and treatment monitoring tasks. At both power settings, ASEs and ASSEs provided accurate location information during HIFU treatment. At the low-power setting case, ASEs and ASSEs provide accurate lesion size in real-time monitoring. Lesion appearance in ASEs and ASSEs was affected by the cavitation bubbles produced at the high-power setting. The results further indicate that the cavitation bubbles influence lesion appearance more in ASEs than in ASSEs. Both ASEs and ASSEs provided accurate size information after a waiting period that allowed the cavitation bubbles to disappear. The results indicate that ASSEs not only improve lesion visualization and size measurement of a single lesion, but, under certain conditions, also help to identify untreated gaps between adjacent lesions with high contrast.
On Kant's argument in the second analogy

L'A. defend la these selon laquelle l'argument de Hume concernant la nature et son independance par rapport a l'esprit s'applique a conception kantienne de la causalite qui presuppose le principe de l'uniformite. Examinant la position de Kant developpee dans la seconde analogie de la «Critique de la raison pure», l'A. montre que l'argument de la permanence des successions de causes et effets dans la nature tombe sous la critique sceptique de Hume.
The estimation of protein secondary structure by laser Raman. Spectroscopy from the amide III' intensity distribution.

The determination of protein secondary structure in aqueous solution has undergone an important advance [ 11. It is now possible to estimate fractions of bi-H-bonded andmonoH-bonded helix, antiparallel P-sheet, parallel P-sheet, and P-turn to within 25% of X-ray diffraction estimates with -70% confidence, whereas before, using circular dichroism (CD) [ 21 or Raman spectroscopy [3], only fractions of total helix and P-sheet were estimated, to within -8%. This improvement has come about mostly through the generation of computer-subtracted difference laser Raman spectra, and specifically through the subtraction of the water spectrum from the amide I spectrum of proteins. Here we present evidence that this general approach can be applied to the amide III’ region of the laser Raman spectrum of proteins in D20 as well, and that estimates of the structure of solvent exchanged regions of the protein can thereby be obtained. When a protein is dissolved in D,O, exposed amide N-H groups exchange with the solvent, and the .amide III vibrations shift to a lower frequency from between 1200 and 1320 cm-’ to what are termed the amide III’ vibrations between 900 and 1000 cm-‘. While several investigations have pursued analyzing the amide III region of the vibrational spectrum for protein secondary structure determination [3-71 little has been done with the amide III’ region. We believe that there are some practical advantages to using the amide III’ over the amide III region for structural studies: (i) Bands due to helix in the amide III region are not very intense relative to the corresponding nonhelical bands (R. W. W., A. K. D., W. L. P., in preparation). (ii) CH deformation modes are strong in the amide III helix region. The amide III’ region seems to be less affected by these kinds of problems. Both helical and S-sheet polypeptides show strong amide III’ bands in DzO. The C-C stretching bands in this region are also conformationally sensitive, and may constructively reinforce the structurally corresponding amide III’ bands. Here, the spectrum of each protein in DzO was subtracted from the corresponding spectrum of the protein in Hz0 so that bands unaffected by deuteration of the amide nitrogen are removed. The resulting difference spectrum represents the true contours of the amide III’ spectrum. Four of these amide III’ difference spectra [6] were then used to calculate the spectra of helix and P-sheet by a procedure similar that in [2] for CD spectra. We have performed these same calculations on the watersubtracted amide I spectra of these proteins in HzO, a method developed more fully in [ 1 ] so that a direct comparison can be made between the results of these two methods.
Effect of mass addition on the heat transfer to a cavity in supersonic flow

Abstract An experimental investigation of the heat transfer to the floor of a rectangular cavity of square planform with secondary injection into the cavity is described. The flow over the cavity was supersonic (Mach number 2·8) and the upstream boundary layer was turbulent. Several configurations of multiple, discrete secondary injection orifices blowing subsonically and supersonically upstream from the recompression step and/or downstream from the separation step are studied; a range of blowing rates, secondary air stagnation temperatures, and cavity floor temperatures were tested and a semi-empirical generalization of the data is developed. As long as the secondary air is colder than the stagnation temperature of the free stream, the heat transfer to the cavity is reduced, often substantially; when it is colder than the wall temperature, the direction of the heat flux can be reversed with moderate amounts of blowing. The most efficient injector configuration calls for blowing upstream from near the floor on the recompression step. Measurements of the cavity bulk temperature with and without blowing and studies of the steady and transient penetration into the cavity of fine graphite particles carried by the oncoming boundary are also presented.
Particle Distribution in Suspension Shear Flow

An earlier proposed constitutive relation for normal stresses originated by random particle fluctuations is used to describe a joint effect of thermal and shear-induced fluctuations on concentrational distributions in suspension flow. Averaged products of components of the fluctuation velocity are evaluated on a basis of the rational mechanics approach combined with a simple kinematic consideration. The equation of momentum conservation of the dispersed phase of a suspension closed with this constitutive relation is applied to unidirectional shear flow in the gravity field and to rotational Couette flow. Coupling of the thermal and shear-induced fluctuations results in that the ability of shear flow to suspend particles has a minimum at a certain particle size, all other things being equal. The developed model provides also for a reasonable explanation of particle distributions observed in Couette flow. The approach based on the consideration of momentum balance for the dispersed phase is proved to lead to an effective equation of convective diffusion of the suspended particles. Coefficients of mutual diffusion due to both thermal and shear-induced fluctuations are drastically different from corresponding self-diffusivities as regards both their scaling and their concentrational dependence.
Strained to the Limit: When a Cyclobutyl Moiety Becomes a Thermodynamic Sink in a Protolytic Ring Opening of Photogenerated Oxetanes

Strained polycyclic oxetanes generated photochemically from the Diels-Alder adducts of cyclic dienes and enones undergo deep skeletal rearrangements under protolytic ring-opening conditions offering expeditious access to chlorohydrins and other products of unique skeletal topology.
Odor as a Contextual Cue in Memory Reactivation in Young Infants

Abstract Three-month-old infants were trained to move a mobile in the presence of a coconut or cherry odor (context). Six days later, a reactivation session took place. Infants were randomly assigned to 4 groups (same odor during training and reactivation, different odor during training and reactivation, no odor present during reactivation, no reactivation). A retention test was conducted 24 h later in the presence of the training odor and mobile. Retention was seen only in the group of infants trained and reactivated with the same odor. This indicates that olfactory contextual cues function in a similar manner to visual and auditory contextual cues in that a novel context, or the absence of the context in which the memory was formed, are ineffective as reminders once the original memory has been forgotten.
Associations of teacher credibility and teacher affinity with learning outcomes in health classrooms

In the present study (N = 633), we examine the role of teacher credibility and teacher affinity in classrooms. We explore the relations among these two characteristics and student gains in knowledge and valuing of learning about HIV and pregnancy prevention across high school classrooms. Results marshaled support for the notion that teacher characteristics are associated with classroom-level gains in learning outcomes. Above and beyond student-level predictors, teacher credibility (aggregated to the classroom level) was positively related to increases in knowledge across classrooms, whereas aggregated teacher affinity was positively related to an increased valuing of learning about HIV and pregnancy prevention across classrooms. Future directions and implications for practice are discussed.
Replacement of the transmembrane anchor in angiotensin I-converting enzyme (ACE) with a glycosylphosphatidylinositol tail affects activation of the B2 bradykinin receptor by ACE inhibitors

To investigate further the relationship of angiotensin I-converting enzyme (ACE) inhibitors to activation of the B2 bradykinin (BK) receptor, we transfected Chinese hamster ovary cells to stably express the human receptor and either wild-type ACE (WT-ACE), an ACE construct with most of the cytosolic portion deleted (Cyt-del-ACE), or ACE with a glycosylphosphatidylinositol (GPI) anchor replacing the transmembrane and cytosolic domains (GPI-ACE). BK or its ACE-resistant analogue were the agonists. All activities (arachidonic acid release and calcium mobilization) were blocked by the B2 antagonist HOE 140. B2 was desensitized by repeated administration of BK but resensitized to agonist by ACE inhibitors in the cells expressing both B2 and either WT-ACE or Cyt-del-ACE. In GPI-ACE expressing cells, the B2 receptor was still activated by the agonists, but ACE inhibitors did not resensitize. Pretreatment with filipin returned the sensitivity to inhibitors. In immunocytochemistry, GPI-ACE showed patchy, uneven distribution on the plasma membrane that was restored by filipin. Thus, ACE inhibitors were inactive as long as GPI-ACE was sequestered in cholesterol-rich membrane domains. WT-ACE and B2 receptor in Chinese hamster ovary cells co-immunoprecipitated with antibody to receptor, suggesting an interaction on the cell membrane. ACE inhibitors augment BK effects on receptors indirectly only when enzyme and receptor molecules are sterically close, possibly forming a heterodimer.
Nafion-H catalysed sulfonylation of aromatics with arene/alkenesulfonic acids for the preparation of sulfones

Synthesis of both symmetric and unsymmetric diaryl/aryl alkyl sulfones is easily achieved by Friedel–Crafts type sulfonylation of aromatics with suitable arene- or alkanesulfonic acids in the presence of Nafion-H, a perfluorinated resinsulfonic acid catalyst.
Risk factors for and complications of distraction osteogenesis.

Distraction osteogenesis is commonly used for limb deformities and reconstruction of bone defects with satisfactory outcome for the patients. However, it is associated with a risk of complications. The present study aims to assess the incidence of complications and to identify the risk factors that may predict distraction osteogenesis-related complications. We retrospectively studied 63 patients (mean age 13.5 years; range 3–57 years) who had 74 distraction osteogenesis procedures from 2004 to 2009. A circular external fixator was used in 58 procedures, and a monolateral in 16 procedures. Fixator’s time, days of treatment, lengthening percentage, bone healing index, distraction regenerate length and index, risk factors and complications were evaluated. The mean follow-up was 5 years (range 2–7 years). Complications occurred in 57 of the 74 procedures (77 %); 70 % were major complications and 30 % were minor. Complications were more common in adults. Bone healing index, days of treatment and fixator’s time were univariate predictors of complications. Bone healing index and adult age were the only multivariate predictors of complications. Adult age and bone healing index are the most important multivariate predictors of distraction osteogenesis-related complications. Routine follow-up after implant removal, selection of younger patients with minor risk factors and shorter fixator’s time are necessary to reduce the rate of distraction osteogenesis-related complications.
Gap Junction Intercellular Communication: A Review of a Potential Platform to Modulate Craniofacial Tissue Engineering

Defects in craniofacial tissues, resulting from trauma, congenital abnormalities, oncologic resection or progressive deforming diseases, may result in aesthetic deformity, pain and reduced function. Restoring the structure, function and aesthetics of craniofacial tissues represents a substantial clinical problem in need of new solutions. More biologically-interactive biomaterials could potentially improve the treatment of craniofacial defects, and an understanding of developmental processes may help identify strategies and materials that can be used in tissue engineering. One such strategy that can potentially advance tissue engineering is cell–cell communication. Gap junction intercellular communication is the most direct way of achieving such signaling. Gap junction communication through connexin-mediated junctions, in particular connexin 43 (Cx43), plays a major role bone development. Given the important role of Cx43 in controlling development and differentiation, especially in bone cells, controlling the expression of Cx43 may provide control over cell-to-cell communication and may help overcome some of the challenges in craniofacial tissue engineering. Following a review of gap junctions in bone cells, the ability to enhance cell–cell communication and osteogenic differentiation via control of gap junctions is discussed, as is the potential utility of this approach in craniofacial tissue engineering.
Seasonal Restructuring of the Ground Squirrel Gut Microbiota Over the Annual Hibernation Cycle

Many hibernating mammals suspend food intake during winter, relying solely on stored lipids to fuel metabolism. Winter fasting in these species eliminates a major source of degradable substrates to support growth of gut microbes, which may affect microbial community structure and host-microbial interactions. We explored the effect of the annual hibernation cycle on gut microbiotas using deep sequencing of 16S rRNA genes from ground squirrel cecal contents. Squirrel microbiotas were dominated by members of the phyla Bacteroidetes, Firmicutes, and Verrucomicrobia. UniFrac analysis showed that microbiotas clustered strongly by season, and maternal influences, diet history, host age, and host body temperature had minimal effects. Phylogenetic diversity and numbers of operational taxonomic units were lowest in late winter and highest in the spring after a 2-wk period of refeeding. Hibernation increased relative abundance of Bacteroidetes and Verrucomicrobia, phyla that contain species capable of surviving on host-derived substrates such as mucins, and reduced relative abundance of Firmicutes, many of which prefer dietary polysaccharides. Hibernation reduced cecal short-chain fatty acid and ammonia concentrations, and increased and decreased concentrations of acetate and butyrate, respectively. These results indicate that the ground squirrel microbiota is restructured each year in a manner that reflects differences in microbial preferences for dietary vs. host-derived substrates, and thus the competitive abilities of different taxa to survive in the altered environment in the hibernator gut.
Self-dual Yang-Mills equations in split signature

Abstract We study the self-dual Yang–Mills equations in split signature. We give a special solution, called the basic split instanton, and describe the ADHM construction in the split signature. Moreover a split version of t'Hooft ansatz is described.
Prevalence, mechanisms, and clinical significance of macroreentrant atrial tachycardia during and following left atrial ablation for atrial fibrillation.

Objectives The purpose of this study was to determine the prevalence and clinical significance of macroreentrant atrial tachycardia (AT) after left atrial (LA) circumferential ablation for atrial fibrillation (AF). Background Linear ablation for AF may result in macroreentrant AT. Methods Three hundred forty-nine patients (age 54 ± 11 years) underwent LA circumferential ablation for AF (paroxysmal in 227). Ablation lines were created around the left-sided and right-sided pulmonary veins, with additional ablation lines in the posterior LA and mitral isthmus. If macroreentrant AT was observed acutely in the electrophysiology laboratory, it was not ablated. If an organized AT occurred during follow-up, the initial strategy was rate control. If AT persisted for > 3 to 4 months, catheter ablation was performed. Results Seventy-one patients (20%) had spontaneous or induced macroreentrant AT (cycle length 244 ± 31 ms) in the electrophysiology laboratory following LA circumferential ablation. During follow-up, 85 patients (24%) experienced spontaneous AT (cycle length 238 ± 35 ms) at a mean of 44 ± 62 days following LA circumferential ablation. Among the 71 patients with macroreentrant AT acutely following LA circumferential ablation, 39 (55%) developed AT during follow-up. Among the 85 patients with AT during follow-up, the tachycardia remitted without a repeat ablation procedure in 28 patients (33%), most commonly within 5 months. Twenty-eight of the 349 patients (8%) underwent a repeat ablation procedure for AT. The critical isthmus was localized to the mitral isthmus in 17 of 28 patients (61%). Conclusions Macroreentrant AT is a common form of proarrhythmia after LA circumferential ablation for AF. Because it may resolve spontaneously, ablation of AT should be deferred for several months.
POLYMER THERMOELECTRET DOSIMETRY.

Radiation dosimetry based on thermoelectrets of nylon, mylar, polystyrene, and teflon is described. The effect of storage environment, forming temperature, and forming field strength have been examined for these four materials. The electret polarization was monitored by measuring the surface potential of the electrets by means of a contactless voltmeter probe. The electrets (except those of nylon) were found to be very stable under normal conditions. In the presence of X-ray or thermal neutron radiation they undergo a rapid and cumulative discharge. The total dosage received can be inferred from a comparison of the initial and residual polarizations. For 50 kV X-rays, a dosage of 1 mR is easily detectable by such measurements, and higher sensitivities are believed to be attainable in principle. Es werden Untersuchungen zur Strahlungsdosimetrie mit Hilfe von Thermoelektreten auf der Grundlage von Nylon, Mylar, Polystyrol und Teflon durchgefuhrt. Insbesondere wird der Einflus der Lagerungsbedingungen, der Formierungstemperatur und der Formierungsfeldstarke studiert. Die Polarisation der Elektrete wurde durch Messung des Oberflachenpotentials unter Benutzung einer kontaktlosen Sonde verfolgt. Unter normalen Bedingungen erwiesen sich alle Substanzen auser Nylon als sehr stabil. Unter Einwirkung von Rontgenbestrahlung oder Bestrahlung mit thermischen Neutronen findet eine schnelle und sich steigernde Entladung statt. Die insgesamt aufgenommene Dosis kann durch Vergleich der anfanglichen und der Restpolarisation ermittelt werden. Fur 50 kV-Rontgenstrahlung ist eine Dosis von 1 m durch derartige Messungen leicht nachweisbar, und es wird erwartet, das noch hohere Empfindlichkeiten erreichbar sind.
Intimate Partner Violence During Pregnancy: Incidence and Associated Health Behaviors in a Rural Population

Objectives: The goal of this investigation was to examine the prevalence of different types of intimate partner violence (IPV) during pregnancy, as well as the association between both physical and psychological IPV and negative health behaviors, including smoking, other substance use, inadequate prenatal care utilization, and nutrition, in a rural sample. Methods: 104 southern Appalachian women, primarily Caucasian and lower SES, completed a pregnancy interview focused on IPV (CTS2) and health behaviors. Medical records were also reviewed. Results: 81% of participants reported some type of IPV during the current pregnancy, with 28% reporting physical IPV, and 20% reporting sexual violence. More than half were current smokers. Physical IPV during pregnancy was associated with significantly increased rates of pregnancy smoking (including decreased rates of quitting and reducing), increased rates of alcohol, marijuana, and harder illicit drug use around the time of conception, and later entry into prenatal care. The experience of psychological IPV during pregnancy was associated with a significantly decreased likelihood of quitting or reducing smoking during pregnancy, an increased rate of alcohol use around the time of conception, and an increased rate of pre-pregnancy obesity. Conclusions: In this sample, pregnancy IPV and smoking occurred at rates well above national averages. Additionally, while physical IPV during pregnancy was associated with several negative pregnancy health behaviors, the experience of psychological IPV, even in the absence of physical IPV, also placed women at increased risk for negative health behaviors, all of which have been linked to poor pregnancy and newborn outcomes.
Decision-making spark chambers

Abstract A wire spark chamber system has been developed in which information can be analyzed within 30 to 50 nsec of the spark time and used to trigger other spark chambers for a more detailed analysis of the same event. The wire chamber system has good spatial resolution, very low mass, a recovery time of less than 1 msec and a fast, low impedance output capable of driving versatile core arrays. By tunning the wires in simple patterns through core arrays, it is possible to get signals whose pulse height is proportional to such things as the number of sparks, the number with more than some minimum separation, the position of a spark and the separation of two sparks. Many other kinds of spatial decisions can be made with these devices such as the recognition of scattering of a particle and coplanarity of two particles. We have used such decision-making spark chambers to trigger an optical spark chamber on two track events. Wires were grouped together at the outputs to give 1 cm spatial resolution. The observed single track efficiency for one gap was greater than 99% and the double track efficiency was greater than 97%.
Glycosaminoglycan accumulation with partial deficiency of beta-glucuronidase in the C3H strain of mice.

Young (60–80 days) mice of the low β-glucuronidase strain, C3H/HeJ, showed no differences in hepatic levels of glycosaminoglycans (GAGs) when compared to the randombred, “normal” Swiss-Webster mice of the same age. However, by 12 months of age hepatic GAG is nearly twice as high in C3H/HeJ mice as in Swiss-Webster mice. Studies of β-glucuronidase, β-galactosidase, and N-acetyl-β-glucosaminidase in four tissues of the two types of mice at the two ages revealed that glucuronidase was the only enzyme with lower activity in the C3H/HeJ strain.
Premature Birth and Asthma Among Young Puerto Rican Children

Puerto Rican children are more likely to have asthma than children in any other racial/ethnic group in the United States, yet little research has examined the factors contributing to childhood asthma among Puerto Ricans. Using data from a representative sample of mainland Puerto Rican children, the present study investigates the relationship between preterm birth and early-childhood asthma (i.e., in the first years of life). The roles of other risk factors (i.e., socioeconomic and demographic characteristics, environmental conditions, and maternal health behavior) in the development of asthma in early childhood also are considered. The analysis reveals a relatively high rate of asthma for preterm children as well as differences between term and preterm children in the risk factors for early-childhood asthma. Measures of socioeconomic status and the cleanliness of the home environment are related to asthma for term, but not preterm, children; in contrast, demographic characteristics and maternal health behavior are important risk factors for asthma among preterm children.
Factors associated with antibiotic prescribing in a managed care setting: An exploratory investigation

This multi-site, cross-sectional, observational study sought to identify attitudinal and social normative factors associated with the prescribing of oral antibiotics to ambulatory patients in a managed care setting. Participants were 25 physicians specializing in internal medicine, family practice or pediatrics from five ambulatory care clinics within a large, fully integrated health care system in a major midwestern U.S. city. The main outcome measure was number of prescriptions per physician written in the fourth quarter of 1994 for each of seven selected antibiotics. Correlational and multiple regression analyses revealed that behavioral intentions were significantly associated (P < 0.05) with both attitudes and subjective norms. However, physicians' attitudes, subjective norms and intentions were not predictive of actual antibiotic prescribing behavior. Prescribing behavior may have been a function of patient-specific rather than general beliefs about antibiotics. Methodological limitations related to the sample size and the sparseness of the utilization data may also have prevented a significant effect of intentions on behavior from being detected. Alternatively, in managed care settings, it is hypothesized that prescribing behavior may have been influenced more by non-psychological factors, such as management systems, formularies and therapeutic substitution programs, than they were by internal, psychological factors such as attitudes, subjective norms and intentions. Managed care is altering the role of the physician as an autonomous decision-maker. In response, models of prescribing must either incorporate variables such as perceived behavioral control to aid in the prediction of non-volitional behavior, model the decision-making of non-physician managers, or forego psychological models in favor of structural or system-level models of drug utilization.
Dioxaheteroatom Cyclics as Initiators for Radical Polymerization

An attractive way to incorporate flame-retarding moieties into oligomers or polymers is to use strained heterocyclic compounds which contain a thermally-labile carbon-carbon bond which will undergo thermolysis at modest temperature to generate a diradical capable of initiating vinyl polymerization. Suitably substituted, they may contain either bromine or phosphorus-containing moieties, or both. The diol precursors to these heterocycles are generally available from reductive coupling of the corresponding ketones. Conversion of the diols to the heterocycles can be accomplished using standard reagents. Phospholanes generated in this way tend to be quite thermally unstable and often degrade within hours to generate a variety of products. On the other hand, siloles derived from appropriate diols display much greater thermal stability. They can be isolated as crystalline solids and may be used to initiate polymerization at 100-200 °C. Incorporation of heterocycle-derived units into the mainchain can impart polymer flame retardancy directly. Alternately, oligomers may be generated for use as flame retardant additives for polymeric materials.
7030 Gastrointestinal endoscopy in a large urban medical center i: esophagogastroduodenoscopy (egd).

Few data exist to describe the practice of gastrointestinal endoscopy in a large urban county hospital. These data represent our experience with EGD at Kings County Hospital (KCHC) during the period 1/97 - 5/99. 767 EGDs were perfromed on 397 men (mean age = 52.4 years) and 362 women (mean age = 57.2). 87.7% were done electively in the GI endoscopy suite, and 12.3% were emergency cases done in the ER (7.3%), the MICU (2.3%), SICU (2.3%), or NICU (0.3%). A therapeautic technique was included in 10% of the procedures. Active or recent UGI bleeding was the most common indication (40%) for EGD. Other indications included epigastric pain (22.3%), dysphagia (5.6%), occult GI bleeding with or without iron deficiency anemia (5.1%), and others (27%). 30% of all examinations were performed with no conscious sedation. The rates for successful completion of emergency and routine procedures were 81% and 90% respectively. Endoscopic diagnoses included esophagitis (19.2%), hiatus hernia (19.2%), candida esophagitis (4.6%), esophageal ulcer (4.0%), esophageal varices (3.9%), Mallory Weiss tear (3.3%), Barrett's esophagus (1.3%), esophageal cancer (2.1%), gastritis (31.9%), gastric ulcer (16.8%), gastric cancer (3.3%), gastric polyp (0.9%), duodenitis (15.4%), duodenal ulcer (12.9%), duodenal polyp (0.9%), abnormal papilla (0.7%), active bleed with no source (0.7%) and normal study (8%). There were only two complications (0.3%), both micro-perforations of the cervical esophagus requiring no invasive treatment. Conclusions: A major fraction of EGD in a large urban inner-city county hospital are done for upper GI bleeding. Many procedures are performed without sedation. The incomplete procedure rate is high, but the complication rate is low. The frequency of normal study is low while 10% of all EGD include a therapeautic technique.
Independent Physiological Predictors of Foot Lesions in Patients With NIDDM

OBJECTIVE To identify and quantify independent physiological risk factors for foot lesions in diabetic patients. RESEARCH DESIGN AND METHODS There were 352 patients enrolled in a 1-year randomized controlled trial aimed at reducing risks for lower-extremity pathology through patient education and system interventions. Inclusion criteria were as follows: being age 40 years or over, being at or above ideal body weight, and having been diagnosed with NIDDM. Participants were predominantly African-American (76%), elderly (mean 60 years of age), indigent (77% with annual income < $10,000), or women (81%) who had diabetes for 10 years. Prospective multivariate modeling used baseline clinical signs (e.g., blood pressure, dermatological characteristics, and neuropathic measures) and laboratory values (e.g., lipid profiles and measures of glycemic control) to predict foot lesions rated using the Seattle Wound Classification. RESULTS When controlling for intervention effects, only measures of neuropathy (monofilament testing [odds ratio {OR} 2.75, 95% CI 1.55–4.88] and thermal sensitivity testing [2.18, 1.13–4.21]) predicted wounds classified 1.2 (minor injury), but investigation of wounds rated at least 1.3 (nonulcerated lesions) indicated baseline wounds (13.41), 3.19–56.26), monofilament abnormalities (5.23, 2.26–12.13), and low HDL (1.63, 1.11–2.39) as predictors. Although fungal dermatitis, dry cracked skin, edema, ingrown nails, microalbuminuria, fasting blood glucose, and hemoglobin A1c were candidates for one or both of the multivariable models ( P < 0.3), they were not significant multivariate predictors. CONCLUSIONS Lesions may be preventable with aggressive screening for peripheral neuropathy and abnormal lipids. Also, these results provide empirical support for the commonly held belief that foot lesions prospectively predict future wounds.
Tethered insect flight: A system for automated data processing of behavioral events

Flight mills to which flying insects are tethered, and which allow measurement of locomotion in a circular path, are used to measure flight capability in terms of frequency, duration, velocity, and distance. Also, they are adaptable to measurement of physiological processes such as respiration and energy consumption. We describe a flight-mill system with floating magnets and Teflon® bearings in its rotor that minimize frictional drag. Rotation (of the mill rotor) is transduced by interruption of a light beam to a phototransistor, which produces a signal monitored by a specially constructed event recorder. The event recorder temporarily stores the data from each mill and then transmits them in proper format for permanent storage on seven-track magnetic tape. The system allows simultaneous data collection from 18 individual insects and provides a computerized interpretation of their performance. The result is an analysis of all the significant parameters of flight that can be derived by measuring duration, velocity, distance, and frequency.
Temporal relationship of choroidal blood flow and thickness changes during recovery from form deprivation myopia in chicks.

When form deprived, young chicks rapidly develop axial myopia, from which they recover if the treatment is ceased at a sufficiently early age. The increased axial growth of the eye is accompanied by choroidal thinning and decreased choroidal blood flow (ChBF). In contrast, during the early part of the recovery process, the choroid thickens, shifting the retina towards the new plane of focus. Little information is available about ChBF during recovery from myopia. Because of the possibility that choroidal thickening during recovery from myopia might be driven by an increase in ChBF, the temporal relationship of ChBF and choroidal thickness changes was examined during such recovery. White Leghorn chicks were form deprived from 3 days of age for 2-3 weeks using detachable plastic diffusers. Axial ocular dimensions, including choroidal thickness, were then measured by high frequency A-scan ultrasonography at various times after the diffusers were removed up to 240 hr. ChBF was measured transclerally immediately following the A-scan ultrasonography, using laser Doppler flowmetry. In the chicks measured immediately after diffuser removal, the vitreous chamber was 29.9% longer, the choroid was 6.4% thinner and ChBF was 13.7% less in the treated than in the non-treated control eyes. These changes are characteristic of myopic chick eyes and are reversible in young eyes. Thus, in chicks examined 7 hr after diffuser removal, the ChBF in recovering eyes was now greater than that in control eyes. This ChBF increase peaked about 19 hr after the diffusers were removed. The mean increase in ChBF in treated eyes for the 7-30 hr monitoring period was 187%, relative to control eyes. ChBF in the treated eyes gradually returned to the control level after this time. By contrast to the early, transient increase in ChBF, significant choroidal thickening was not observed in treated eyes until 30 hr after diffuser removal, and continued to increase relative to control eyes over the remainder of the monitoring period, reaching a final mean value of 182%. This study demonstrates, in chick eyes recovering from form deprivation myopia, large increases in ChBF that preceded increases in choroidal thickness and were also more transient than the latter. These results raise the possibility that the increase in ChBF may trigger or even drive the subsequent onset of choroidal expansion, perhaps by facilitating the filling of the choroidal lymphatic lacunae that are well developed in the avian eye.
Evolution of an Information Literacy Curriculum for Third-Year Medical Students

Information literacy curriculum for third-year medical students at Northwestern University has evolved over several years under the guidance of librarians at the Galter Health Sciences Library. Starting as a series of rotation-specific information resource overviews, initial evaluation and feedback led to the curriculum being developed to include more focused and interactive clinical information sessions with a quiz-based assessment. Future enhancements will include web-based self-directed learning using online tutorials, additional search exercises that mimic the on-the-go clinical environment, and better assessment of the curriculum's impact on students' information literacy and clinical search skills.
Human renin inhibition by a diazoacyl reagent: relationship of the enzyme to other proteinases.

Abstract Human renin is inactivated by a diazoacyl compound (diazoacetylglycine ethyl ester; N 2 CHCO-Gly-OEt) in the presence of Cu(II). The mechanism of the inactivation is presumably identical to that which has been determined for pepsin and several other proteinases: esterification of the β-carboxyl of an aspartic acid residue at the active site of the enzyme. Renin's inhibition by the diazoacyl reagent, its specificity toward a hydrophobic sequence, and its inhibition by pepstatin, all suggest a close relationship to the acid proteinases, especially pepsin and cathepsin D. However, renin, a neutral proteinase, would be better classified together with other diazoacyl-inhibited enzymes by active site rather than pH optimum. The term “aspartic proteinase” is suggested for this group of enzymes.
Mercury dihydride forms a covalent molecular solid

Atomic mercury in solid hydrogen reacts when subjected to mercury arc irradiation to form the linear HgH2 molecule with strong IR absorptions at 1902.3 and 772.8 cm−1. Annealing leads to HgH2 dimer and trimer and warming above 7 K allows hydrogen to sublime and solid HgH2 to form. This covalent molecular solid is characterized by strong IR absorptions at 1802, 739 and 673 cm−1 and by decomposition at 150–170 K. Solid para-hydrogen gives sharper HgH2 absorptions at 1905.8 and 774.3 cm−1 and forms a more amorphous HgH2 solid with bands at 1813, 741 and 683 cm−1.
Coronary risk factors: Insights from framingham

Data collected during almost 40 years' follow-up of over 10,000 participants in the Framingham Study and the Framingham Offspring Study are reviewed to highlight the influence of the following factors on the risk for coronary heart disease: systolic blood pressure; lipids (total cholesterol, high-density-lipoprotein low-density-lipoprotein cholesterol, and triglycerides); cigarette smoking; diabetes mellitus; obesity; and left ventricular hypertrophy.
Nifedipine in the management of hypertensive emergencies: Report of two cases and review of the literature

Calcium channel blockers are assuming increasingly important roles in the practice of emergency medicine. Two cases and a review of the literature relating to treatment of hypertensive emergencies with nifedipine are presented. Nifedipine has a rapid onset of action (buccal, 10-15 minutes; oral, 30-45 minutes) and peak effect (buccal, 30 minutes, oral, 60 minutes). The duration of effects is four to six hours regardless of the route of administration, with a mean arterial pressure reduction of 21.6% (248/134 mm Hg to 165/87 mm Hg). In patients with severe hypertension and left ventricular failure, a consistent reduction in systemic vascular resistance (2,088 dynes/sec/cm-5 to 1242 dynes/sec/cm-5) and cardiac index (2.76 l/min/m2 to 3.77 l/min/m2) has been reported. The patients in this study had severe hypertension (systolic blood pressure greater than 180 mm Hg, diastolic blood pressure greater than 120 mm Hg) and end organ involvement (including heart failure, left ventricular strain, headache, confusion, dizziness, and shortness of breath). Nifedipine (10 mg) was administered buccally with prompt reduction of blood pressure and resolution of the patients' symptoms. Nifedipine appears to be a safe, effective agent for the management of hypertensive emergencies. Its pharmacokinetic profile and routes of administration make it particularly valuable in the practice of emergency medicine.
An early example of evidence-based medicine: hypoxemia due to nitrous oxide.

Diffusion anoxia. By Bernard Raymond Fink. Anesthesiology 1955; 16:511–14. In 1955, Dr. Bernard Raymond Fink published his findings that described the mechanism by which hypoxemia occurred when nitrous oxide–oxygen anesthesia was discontinued and room air breathing commenced. Using an ear oximeter and brachial artery blood gases, he measured oxygen saturation in eight healthy patients who had received 75% nitrous oxide–25% oxygen for gynecologic surgery. He showed that oxygen saturation decreased from 5% to 10% and often reached a value below 90% when the patient began room air breathing after the nitrous oxide–oxygen was discontinued. The effect was seen over a 10-min period. He concluded that “anoxia arises because the outward diffusion of nitrous oxide lowers the alveolar partial pressure of oxygen.” This phenomenon can become a causative factor of cardiac arrest in patients with impaired pulmonary or cardiac reserves.
Short-term prediction of solar irradiance using time-series analysis

Abstract A new statistical model for solar irradiance prediction is described. The method makes use of the atmospheric parameterizations as well as a time-series model to forecast a sequence of global irradiance in the 3-10 min time frame. A general literature survey of some of the prominent research of the recent past reveals a definite lack of irradiance models that approach subhourly intervals, especially in the range mentioned. In this article, accurate parameterizations of atmospheric phenomena are used in a prewhitening process so that a time-series model may be used effectively to forecast irradiance components up to an hour in advance in the 3-10 min time intervals. Input requirements are not very restrictive; the model requires only previous global horizontal irradiance measurement at a site. Results show that when compared with actual data at two locations in the southeastern United States, the forecasts are quite accurate, and the model is site-independent. Under some instances, forecasts may b...
Homotopy equivalence and hemeomorphism of 3-manifolds

IN THIS paper we extend the class of 3-manifolds which are determined up to homeomorphism by their fundamental groups to the class of closed orientable irreducible 3-manifolds containing a singular surface satisfying two properties, the l-line-intersection property and the 4-plane property. A basic problem in the classification of 3-dimensional manifolds is to decide to what extent the homotopy type of a closed manifold determines the manifold up to homeomorphism. In the case of 3-manifolds with finite fundamental groups, it is known that there are homotopy equivalent manifolds which are not homeomorphic, but there are no known examples of closed orientable irreducible 3-manifolds with isomorphic infinite fundamental groups which are not homcomorphic. Waldhausen [30] and Heil Cl23 proved that if M and M’ are Haken 3-manifolds which have isomorphic fundamental groups then they are homcomorphic. If M and M’ arc hyperbolic then the Mostow rigidity theorem implies the same result [19]. but if only M is assumed to be hyperbolic then it is unknown. Boehme [3] extended Waldhausen’s theorem to certain non-Haken Seifert fiber spaces. Scott [27] showed that a closed orientable irreducible 3-manifold which is homotopy equivalent to a Seifcrt fiber space with infinite fundamental group is homeomorphic to that Seifert fiber space. Many of these Scifert fiber spaces are non-Haken. To date however, Seifert fiber spaces have provided the only examples of non-Haken 3-manifolds which are known to be determined up to homeomorphism by their fundamental groups. For manifolds with boundary there are simple examples of non-homemorphic homotopy equivalent Haken manifolds, such as the product with the circle of a thricepunctured sphere and the product with the circle of a once-punctured torus. Such examples are well understood in terms of the characteristic decomposition of the 3-manifold [17] [16]. Another possible source of troublesome examples comes by taking the connected sum of a 3-manifold with a fake homotopy 3-sphere, resulting in a homotopy equivalent non-homeomorphic 3-manifold. This possibility would be ruled out by a successful solution to the Poincari conjecture. To get around this potential problem we work with irreducible 3-manifolds, in which any 2-sphere bounds a bail. Since non-orientable P2-irreducible 3-manifolds are always Haken, we restrict our attention to the orientable case. For simplicity of notation, we sometimes follow the convention of not distinguishing between a map of a surface into a manifold M and the image of the map. When it is
Redundancy optimization problem with warm-standby redundancy

This paper describes and demonstrates a solution methodology that determines optimal design configurations that maximize the reliability of a wide range of non-repairable systems. The problem formulation considers the generic case of warm-standby redundancy and extends state-of-the-art reliability optimization techniques in several dimensions: (1) non-constant component hazard functions, (2) warm standby components including cold and hot standby situations, (3) imperfect switches, (4) k-out-of-n redundancy structures, (5) multiple component choices, and (6) redundancy strategy choices. The problem involves selection of components, redundancy strategies, and redundancy levels to maximize system reliability subject to constraints. Optimal solutions are determined based on an equivalent binary integer programming formulation. Compared to other available methods, the proposed methodology more accurately models many engineering design problems with both active and standby redundancies. Previously, it has been difficult to determine optimal solutions for this class of problems or to calculate system reliability efficiently. The methodology is successfully demonstrated on a large problem with 14 subsystems with arbitrary failure distributions.
The current status of the Penman language generation system

Penman is one of the largest English language generation programs in the world. Developed mainly at ISI/USC, it is the result of over 15 person-years' work, and forms the core of an investigation of the computational aspects of the theories of Systemic Functional Linguistics.
Postoperative fibrous cardiac constriction.

Abstract Two patients with postoperative fibrous cardiac constriction are described. Unlike postoperative pericardial or epicardial constriction, the fibrous constricting layer in these patients envelops the vein bypass grafts and is separate from the pericardium, which is not involved. Surgical management of these patients is difficult and hazardous; a strategy is outlined.
Raman spectrum and molecular structure of ozone

AN attempt has been made to find the Raman spectrum of ozone, using a 30 per cent solution of ozone in liquid oxygen and a mercury arc as the exciting light. The solution is a dark purple in colour and absorbs the mercury line at 4358 A. quite considerably. The mercury line at 4046 A., however, is scattered fairly strongly, but it has no strong Raman companions. There is an extremely weak doublet corresponding to a mean frequency shift of 1280 cm.−1, but no other Raman lines could be observed even with exposures lasting 80 hours. The spectrograph used was not particularly fast, but photographs of the weak oxygen line at 1550 cm.−1 from 4046 A. could be obtained in 10 hours.