Second-harmonic generation and the orbital angular momentum of light.
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
L Allen
Publications and source records attributed to L Allen.
Localization and developmental expression of surfactant proteins D and A in the respiratory tract of the mouse.
Surfactant protein D (SP-D) is synthesized and secreted by pulmonary epithelial cells. Like surfactant protein A (SP-A), SP-D is a collagen-like glycoprotein belonging to the "collectin" class of C-type lectins that may play an important role in pulmonary host defense. To begin studies on SP-D gene regulation and function using the mouse as an animal model, we identified the cellular sites of SP-D gene expression in adult mouse lung and trachea and characterized the developmental expression of SP-D mRNA in murine fetal and newborn lungs. We compared these findings with similar studies for murine SP-A, which has an established role in surfactant function and metabolism and a probable role in pulmonary host defense. SP-D mRNA and protein were readily detected by in situ hybridization and immunocytochemistry in alveolar type II and nonciliated bronchiolar epithelial cells of the lung, as well as in cells of the tracheal epithelium and tracheal submucosal glands of the adult mouse. Although SP-A mRNA and protein were also localized to alveolar and nonciliated bronchiolar epithelial cells of the murine lung, there was no detectable labeling for either SP-A mRNA or protein in the murine trachea. Expression of murine SP-D mRNA was first detected by Northern blot analysis on d 16 of gestation in timed-pregnant mice, with an average gestational period of 17 d, and this increased dramatically before birth and during the immediate postnatal period. The developmental expression of murine SP-A mRNA paralleled that of SP-D except that there was a small decrease in mRNA content on postnatal d 5. These studies provide the first description of the cellular distribution and developmental expression of SP-D in mouse lung, which will be important for interpreting future studies of SP-D gene expression in transgenic animal models. In addition, these studies provide the first documentation that, unlike SP-A, SP-D is synthesized not only in the lung but also in submucosal glands of the trachea.
Animals↗
Hodgkin's disease of the orbit with intracranial extension.
A rare presentation of intraorbital Hodgkin's lymphoma in a patient without prior history of systemic disease who complained of episodic monocular visual loss with minimal proptosis is reviewed. The case is further distinguished by intracranial extension of the tumor. A literature review highlights such an unusual event against the background of prior experience. Despite the fact Hodgkin's disease accounts for about 30% of systemic lymphomas, it rarely occurs in the orbit, where non-Hodgkin's lymphomas account for practically all lymphomas studied. Hodgkin's disease has occurred in patients with known systemic disease in its terminal stages and usually with proptosis as the presenting symptom. We present the case of a young man with intraorbital Hodgkin's disease whose presenting symptom was recurrent transient episodes of complete monocular visual loss. His condition was further distinguished by seeding of the skull base and dura by tumor.
Adult↗
The anterior hitch method of tympanic membrane repair.
Anterior perforations of the tympanic membrane have been previously shown to have a higher failure rate than others following tympanoplasty procedures. A technique has been previously described utilizing an anterior hitch graft stabilization with avoidance of anterior blunting of the tympanic membrane. Follow-up cases in which this technique has been utilized show greatly improved results in terms of perforation closure.
Child, Preschool↗
Responses of systemic and pulmonary veins to the presence of an intravascular stent in a swine model.
The outcome of stent implantation for children with pulmonary venous obstruction has been characterized by late reocclusion associated with a marked vessel neointimal proliferation. The purpose of this study was to compare the responses of the systemic vein and pulmonary vein to the presence of an intravascular stent, using a Yorkshire swine (N = 10) model. Under cardiopulmonary bypass, a single Palmaz stent was placed in the inferior vena cava (IVC) and right lower pulmonary vein (PV) with sacrifice at 4.9-6.1 months. Angiography and hemodynamic data were determined at 1 and 3 months post-stent implant and prior to euthanasia. All stents were found to be patent, with no difference in degree of thrombosis or neointimal formation. No statistical difference was found in the initial and final stent diameter for both inferior vena cava and pulmonary vein stents (PV initial 6.8 +/- 0.9; final 7.1 +/- 0.6) (IVC initial 10.4 +/- 1.2; final 10.4 +/- 1.2). Electron microscopy demonstrated smooth endothelialization of both pulmonary and systemic venous stent devices. No thrombosis was found on gross morphology. The data indicate that there is no intrinsic difference in the response of the pulmonary vein to the presence of a stent device. The clinical experience of restenosis following stent implantation for pulmonary vein stenosis appears to be more related to variables of final stent diameter combined with the marked intrinsic abnormal vessel architecture, as seen with this condition.
Angiography↗
Development and validation of adolescent-perceived microsystem scales: social support, daily hassles, and involvement.
Developed and validated instruments for urban and culturally diverse adolescents to assess their self-reported transactions with family, peer, school, and neighborhood microsystems for the constructs of social support, daily hassles, and involvement. The sample of 998 youth were from schools in three Eastern cities with high percentages of economically disadvantaged youth. Data were collected before and after the transition to junior high school or to senior high school. Blacks constituted 26%, whites 26%, and Latinos 37% of the sample. Factor analyses confirmed and enhanced the hypothesized four-factor microsystem factor structure for support, hassles, and involvement; internal consistency and stability coefficients were consistent with these structures. In general, the microsystem factors were common across gender, ethnicity, and age. However, when group differences did occur on these demographic variables, they tended to validate the salience of microsystem specificity. In contrast to the total scores, the microsystem-specific factors yielded more meaningful and differential information with regard to demographic differences and the mediating processes across a school transition.
Adolescent↗
Dichoptic and physical information combination: a comparison.
Two experiments, in which information from two different kinds of degraded (low-pass filtered and regionally averaged or blocked) visual stimuli (aircraft silhouettes) was combined, are reported. In the first experiment, the degraded images were perceptually combined by being separately presented to each eye in a dichoptic viewing situation. Both stimuli in both presentations were masked by identical random visual interference. When the two stimuli were visually fused, performance in a discrimination task was enhanced over that in control situations in which only one of the two stimuli was presented. In the second experiment the two degraded stimuli were physically superimposed prior to binocular presentation, with a similar result. The results of this hybrid (masking/binocular summation) experiment suggest that true advantageous information pooling occurs when these two types of degraded stimuli are combined either physically or dichoptically.
Attention↗
Comprehensive appraisal of 239 + 240Pu in soils around Rocky Flats, Colorado.
Plutonium contamination of soils around Rocky Flats Environmental & Technology Site, near Golden, Colorado, resulted from past outdoor storage practices and subsequent remobilization due to inadequate cleanup practices. Until now human-health risk assessment has not been performed because of a lack of sufficient information regarding the spatial extent of 239 + 240Pu in soils. The purpose of this work was to elucidate the extent of plutonium contamination in surface soils, and to assess the uncertainty associated with the spatial distribution of 239 + 240Pu around Rocky Flats Environmental & Technology Site. Four data sets were collected or compiled for this investigation: (1) samples collected from 240 plots of 1.01- or 4.05-hectare by compositing 25 evenly-spaced samples from the upper 0.64 cm in each plot; (2) samples collected from the upper 5 cm of soil in 167 of the same 240 plots by compositing 10 samples from the center of each plot; (3) historical data compiled from samples collected between 1969 and 1973, considered to be the most indicative of the original release; and (4) the exhaustive data set that contains the samples from 1, 2, and 3 and other published data sets collected between 1974 and 1994. These latter samples varied in depth and method of sampling. Plutonium activity reported in the exhaustive data set ranged from 0.03 Bq kg-1 to 407,000 Bq kg-1 with a mean of 1,443 Bq kg-1, median of 6.6 Bq kg-1, standard deviation of 18,463 Bq kg-1, and a coefficient of variation of 12.6. The technique of nonparametric indicator kriging was used to model four conditional cumulative distribution functions of 239 + 240Pu in soils around Rocky Flats Environmental & Technology Site. Each of the conditional cumulative distribution functions was used to generate an E-type (mean of the conditional cumulative distribution functions) surface. The resulted surfaces were consistent with the hypothesis that the westerly winds were the dominant mechanism of plutonium dispersal. Other processes, such as downstream transport of sediment along local southeast-trending drainages, may have additionally moved small amounts of plutonium. The conditional cumulative distribution functions were also used to construct probability of exceedance maps of 239 + 240Pu in soils. For the purpose of this report two threshold values for the probability maps were selected: (1) the mean and the highest measured global fallout of plutonium (1.48 and 2.96 Bq kg-1, respectively); and (2) the programmatic preliminary remediation goal for residential occupancy scenario (126 Bq kg-1).(ABSTRACT TRUNCATED AT 250 WORDS)
Colorado↗
Atomic motion in light beams possessing orbital angular momentum.
Explore the source record for details and available documents.
Journal Article↗
A type I cell-specific protein is a biochemical marker of epithelial injury in a rat model of pneumonia.
In this study we determined whether the alveolar fluid content of a specific epithelial type I cell protein, rTI40, can be used as a biochemical marker for lung injury. A model of alveolar epithelial injury was developed by instilling Pseudomonas aeruginosa bacteria (PA103) into the airspaces of anesthetized, ventilated rats. After 6 h, the alveolar fluid content of rTI40 from PA103-treated rats was increased over 80-fold in comparison to alveolar fluid from control rats (P < 0.05). This increase in rTI40 correlated with both morphological evidence of injury to alveolar epithelial type I cells and increased permeability of the alveolar epithelium to protein tracers. In contrast, the lactate dehydrogenase activity of alveolar fluid from PA103-treated rats was elevated only threefold over control values at 6 h (P < 0.05). In a second study using a less injurious strain of P. aeruginosa (PA103 exsA::omega), the alveolar fluid content of rTI40 was the same as control values. These findings indicate that the alveolar fluid content of a type I cell-specific protein can be used as a sensitive and specific biochemical marker of type I cell injury.
Animals↗
Health and social characteristics and children's cognitive functioning: results from a national cohort.
OBJECTIVES: The purpose of this study was to examine the associations between cognitive functioning in children and sociodemographic, family, and health characteristics. METHODS: Data from phase 1 of the third National Health and Nutrition Examination Survey were used to evaluate performance on standardized cognitive tests in a representative sample of 2531 children 6 to 16 years of age. Multivariate analyses were used to assess independent associations between covariates and test performance. RESULTS: Lower income, minority status, and lower education of an adult reference person (one of the persons in the household who owned or rented the home) were independently associated with poorer performance on all cognitive subtests. To a lesser degree, general health status, history of birth complications, and sex also were independent predictors of performance for some of the subtests. CONCLUSIONS: These findings illustrate disparities in cognitive functioning across sociodemographic and health characteristics of children in the US population. They suggest the need for public health policies to take a multifaceted approach to optimizing childhood environments in order to overcome the effects of socioeconomic and minority status.
Adolescent↗
The effect of combinations of image degradations in a discrimination task.
This paper explores the ways in which combinations of image degradations affect discrimination. Nine experiments are described that examine the discriminability of visual images that are degraded with three types of information reducing transformations: random punctate visual interference, low-pass spatial frequency filtering, and local area (i.e., block) averaging. The results of these experiments characterize a powerful visual ability to discriminate highly degraded stimuli unless that ability is severely challenged by relatively high levels of random visual interference. Discriminative commutativity of the orders in which the other two degradations are imposed is demonstrated. That is, the order in which the degradations are applied does not affect the final discriminative outcome. This result is in contrast to predictions from relevant mathematics and direct examination of the images produced by both orders of degradation. The commutativity is attributed to the particularly strong effect of the low-pass spatial frequency filtering degradation on the discrimination process. This study also demonstrates that combinations of degradations in a discrimination task always result in a reduction in performance, and never in the improvement that has been reported for recognition. This difference is attributed to the fact that form discrimination is mediated mainly by local features and high-frequency spatial components, whereas recognition is mediated mainly by global features and low-frequency spatial components.
Adult↗
Combining image degradations in a recognition task.
Six experiments are reported that investigate the effect on form recognition performance of combining three kinds of stimulus degradations: local area averaging of intensities, low-pass spatial frequency filtering, and random dot visual interference. The effects are shown to be more complicated than previously reported in simple demonstrations. The complexity of the results suggests that models based on single stimulus attributes such as energy or spatial frequency spectrum probably cannot account for the data. Eclectic theories that invoke combinations of redundant processes may be necessary for describing visual recognition phenomena, even within the limited domain examined in this study.
Adult↗
Light-induced torque on moving atoms.
Explore the source record for details and available documents.
Journal Article↗
Wound complications in patients receiving adjuvant chemotherapy after mastectomy and immediate breast reconstruction for breast cancer.
A retrospective study was done to evaluate the frequency and severity of wound complications in 112 patients with breast cancer who received adjuvant chemotherapy following mastectomy with immediate breast reconstruction. Data on wound complications were available for 120 mastectomies. The rate of complications in 36 mastectomies treated with chemotherapy after mastectomy and immediate reconstruction was compared to that in 84 mastectomies not receiving adjuvant therapy. There were 25 wound complications (20.8%) in the entire group. The rate of wound complications was 27.8% (10 of 36 mastectomies) in the group treated with adjuvant chemotherapy and 17.9% (15 of 84 mastectomies) in the group that did not receive adjuvant therapy (P = 0.13). No patient had a delay in the initiation of adjuvant therapy because of wound complications secondary to immediate reconstruction. Logistic regression analysis found no correlation between age, type of operation, tumor pathology, stage, number of lymph nodes harvested, type of prosthesis or chemotherapy, and wound complications in patients undergoing immediate breast reconstruction after mastectomy. The frequency of wound complications was not increased in patients receiving adjuvant chemotherapy after mastectomy and immediate breast reconstruction. The administration of adjuvant chemotherapy does not need to be delayed in patients who have had immediate breast reconstruction following mastectomy for breast cancer.
Antineoplastic Combined Chemotherapy Protocols↗
Quantum theory of radiation pressure on a dielectric slab.
Explore the source record for details and available documents.
Journal Article↗
Treatment of clozapine-induced obsessive-compulsive symptoms with sertraline.
Explore the source record for details and available documents.
1-Naphthylamine↗
Psychophysical foundations of a model of amplified night vision in target detection tasks.
In this article we examine some of the basic psychophysics relevant to amplified night vision devices. These devices produce images that are substantially different from ordinary visual scenes. Distortions in contrast and luminance and the introduction of visual interference and geometrical artifacts contribute to unusual viewing conditions. We carried out experiments to determine the effect of these parameters of the image on a highly controlled visual target detection task simulated on a computer graphics system that closely models a night vision device. Our results indicate that display luminance and geometrical artifacts degrade detection performance only slightly, whereas contrast and visual interference have a substantial degrading effect.
Adult↗