Health effects of airborne pollutants, particularly in swine confinement stalls, from the viewpoint of occupational medicine]

From the point of view of occupational respiratory medicine, an overview on potential health effects of airborne pollutants particularly in swine confinement houses is presented. Airway diseases are the most frequent occupational disorders among farmers in many countries around the world including Germany. Due to various methodological reasons, epidemiological studies in farming populations are more difficult to perform than among non-farmers. Major constituents of swine confinement dust include bacteria, endotoxin, mites, fungal spores, and animal dander. Gaseous pollutants include ammonia, methane, and hydrogen sulfide. In a variety of cross-sectional studies, high prevalences of respiratory symptoms and non-obstructive (and obstructive) bronchitis and Organic Dust Toxic Syndrome have been reported in pig farmers. Nasal and bronchial provocation challenges with swine confinement dust include influx of neutrophils and other inflammatory cells as well as mediators. In cross-sectional and longitudinal studies, endotoxin turns out as the probably most relevant parameter associated with lung function impairment. Further studies are clearly needed focusing on the prognosis of non-obstructive bronchitis in swine farmers and on health effects of reducing airborne contaminants in swine confinement houses.     

Leiomyoma-related bleeding: a classic hypothesis updated for the molecular era

Leiomyomas are an important cause of menorrhagia and other forms of abnormal uterine bleeding. The pathogenesis of this process is largely unknown, however. A classic theory, first suggested by Sampson's work in 1912 (Surg. Gynecol. Obstet., 14, 215-230), states that local dysregulation of the vascular structures in the uterus is responsible for this abnormal bleeding. Recent work demonstrates dysregulation of a number of growth factors in the myomatous uterus. As many of these factors regulate the process of angiogenesis or have other effects on vascular structures, we hypothesize that this dysregulation of growth factors or their receptors provides the molecular mechanism underlying these vascular abnormalities. In turn, these abnormal vessels lead women with leiomyomas to experience menorrhagia. Factors that may prove to be important in this process include basic fibroblast growth factor, vascular endothelial growth factor, heparin-binding epidermal growth factor, platelet-derived growth factor, transforming growth factor-beta, parathyroid hormone-related protein and prolactin. Current treatment regimens for women with leiomyoma-related bleeding depend on manipulation of the steroid hormone environment. By better understanding the pathogenesis of this disease process, therapies directed against growth factor abnormalities may result in better treatment with less harmful side-effects.     

Electronic band structure calculation and nuclear spin-lattice relaxation in chromium hydrides

The angular-momentum components of the density of states (DOS) were calculated by the FP-LAPW method for stoichiometric CrH having either hexagonal (anti-NiAs) or cubic (NaCl or ZnS) types of structure. The shape of the DOS of the metal 3d states is remarkably similar for the two models of cubic structure, and differs only slightly from that for the hexagonal structure. The DOSs have been used to calculate the ⁵³Cr nuclear spin-lattice relaxation rates. It is found that that the s and p electron contributions to the relaxation rates are negligibly small due to their very low partial densities of states at the Fermi level. The d-orbital contributions are dominant and the core-polarisation and d-dipolar contributions play a minor role. The experimental relaxation rates measured in hexagonal CrH_0.97 and CrH_0.93 and cubic CrH_0.97 indicated the presence of magnetic impurities in the samples, the contribution of which was subtracted from measured relaxation rates. It was found that the intrinsic relaxation rates are reasonably well reproduced by theoretical calculations.     

Extension and source/drain design for high-performance FinFET devices

Double gate devices based upon the FinFET architecture are fabricated, with gate lengths as small as 30 nm. Particular attention is given to minimizing the parasitic series resistance. Angled extension implants and selective silicon epitaxy are investigated as methods for minimizing parasitic resistance in FinFETs. Using these two techniques high performance devices are fabricated with on-currents comparable to fully optimized bulk silicon technologies. The influence of fin thickness on device resistance and short channel effects is discussed in detail. Devices are fabricated with fins oriented in the <100> and <100> directions showing different transport properties.     

Fitted Elmore delay: a simple and accurate interconnect delay model

In this brief, we present a new interconnect delay model called fitted Elmore delay (FED). FED is generated by approximating HSPICE delay data using a curve fitting technique. The functional form used in curve fitting is derived based on the Elmore delay (ED) model. Thus, our model has all the advantages of the ED model. It has a closed-form expression as simple as the ED model and is extremely efficient to compute. Interconnect optimization with respect to design parameters can also be done as easily as in the ED model. In fact, most previous algorithms and programs based on ED model can use our model without much change. Most importantly, FED is significantly more accurate than the ED model. The maximum error in delay estimation is at most 2% for our model, compared to 8.5% for the scaled ED model. The average error is less than 0.8%. We also show that FED can be more than 10 times more accurate than the ED model when applied to wire sizing.     

RU486 suppresses prolactin production in explant cultures of leiomyoma and myometrium

OBJECTIVE: To assess the action of RU486 (mifepristone), in the presence and absence of P, on PRL production by explant cultures of leiomyoma and myometrium. DESIGN: Explant cultures using tissue from nine premenopausal women undergoing hysterectomy in the proliferative phase of the menstrual cycle; immunohistochemical staining of tissue sections from five patients for P receptor (PR) subtype. MAIN OUTCOME MEASURES: Prolactin secretion (measured by RIA), lactate dehydrogenase secretion (measured by quantitative colorimetric assay), and immunohistochemistry for PR subtype. RESULTS: Prolactin secretion was decreased in leiomyomas by RU486 at concentrations of 10(-7) M and 10(-5)M when normal serum-containing medium was used. In experiments with all detectable P removed from serum, PRL secretion was suppressed in both leiomyomas and myometrium at an RU486 concentration of 10(-7)M. Immunohistochemistry results suggest that the A form of the PR is the dominant form in both leiomyomas and myometrium. CONCLUSIONS: Prolactin production is suppressed in both leiomyomas and myometrium after treatment with RU486 in vitro, and this suppression may serve as a marker for the clinical effectiveness of agents used in the treatment of leiomyomas.     

MOSFET technology for low-voltage/low-power applications

Certain limits influence MOSFET technology in low-voltage applications. When we reduce the power supply voltage in modern short-channel devices, both active power dissipation and hot carrier reliability improve more than Linearly. However, strong off-state power consumption requirements and increasing numbers of FETs in each integrated circuit, combined with the physical limit to the subthreshold slope, force designers to choose between high performance and high density     

Likelihood based hierarchical clustering

This paper develops a new method for hierarchical clustering. Unlike other existing clustering schemes, our method is based on a generative, tree-structured model that represents relationships between the objects to be clustered, rather than directly modeling properties of objects themselves. In certain problems, this generative model naturally captures the physical mechanisms responsible for relationships among objects, for example, in certain evolutionary tree problems in genetics and communication network topology identification. The paper examines the networking problem in some detail to illustrate the new clustering method. More broadly, the generative model may not reflect actual physical mechanisms, but it nonetheless provides a means for dealing with errors in the similarity matrix, simultaneously promoting two desirable features in clustering: intraclass similarity and interclass dissimilarity.     

Quantification and rejection of ocular artifacts in auditory evoked fields in schizophrenics

PURPOSES: To determine what factors affect medical expenditure for the aged insured by the National Health Insurance among secondary medical care areas. METHOD: The original data of municipalities were combined and converted into the data of secondary medical areas. The original data included medical expenditure of the aged in 1994, medical supply factors per 100,000 population (numbers of doctors, numbers of general beds in hospitals, numbers of clinics, etc.) and socio-economic factors (income, proportion of employees for three sectors of industries, population density, average size of family, etc.). Medical expenditures for inpatients and outpatients were used separately as independent variables. The medical supply and socio-economic factors have been used as dependent variables. Multiple regression models were applied to clarify the differences in the contributing factors between inpatient and outpatient. RESULTS: 1. The maximum inpatient and outpatient medical expenditures for the aged are respectively 4 times and 2.6 times more expensive than minimum expenditures among secondary medical care areas. 2. The numbers of beds, income per capita, numbers of doctor, average size of family, proportion of employees for third level industry and income accounted for 57.4% of variance in inpatient medical expenditure of the aged. 3. The proportion of employees for first level industry, the numbers of beds and average members of family accounted for 21.4% of variance in outpatient medical expenditure of the aged. 4. Medical expenditure for inpatients related with medical supply and socioeconomic factors differently from that of outpatients.