643 research outputs found
Sensitivity Studies of Forty-Four Strains Mastitis Producing Organisms to Chloramphenicol
The purpose of this investigation was to obtain an indication of the possible value of chloramphenicol in the treatment of bovine mastitis. In vitro tests were run to determine what concentrations of the antibiotic are effective in inhibiting the growth of organisms isolated from field cases of bovine mastitis
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Influence of carrier particle size and surface roughness on the aerosol performance of DPI formulations
textThe influence of the size and morphology of carrier particles on drug dispersion performance from passive dry powder inhalers has been extensively studied topic, and a consensus has been reached regarding the adverse effect that larger carrier particle diameters impart to aerosol performance. However, previous studies have generally employed only a few carrier particle size fractions, generally possessing similar surface characteristics. Accordingly, theories developed to explain the influence of the physical characteristics of carrier particles on performance relied heavily on both extrapolation and interpolation. To fill in the gaps from the literature and simultaneously evaluate the influence of carrier particle size and morphology, a comprehensive study was undertaken using 4 lactose grades, each sieved into 13 contiguous sizes, to prepare 52 formulations incorporating a unique lactose grade-size population. The aerosol performance results indicated that large carrier particles possessing extensive surface roughness can improve drug dispersion, in contrast to what has been previously reported. It is proposed that this may be attributed to mechanical detachment forces arising from collisions between the carrier particle and inhaler during actuation. Based on these observations, a novel dry powder inhaler platform was developed, employing carrier particles much larger (> 1 mm) than previously explored in both the scientific and patent literature. Optimization of this technology required the judicious selection of a carrier material, and following an extensive screening process, low-density polystyrene was selected as a model candidate. Given its low mass, diameters in excess of 5-mm could be employed as carriers while still generating high detachment forces. To minimize drug particle aggregation, a novel drug-coating method employing piezo-assisted particle dispersion was developed to compensate for the reduced surface area of the novel carrier particles. In addition, the selection of a suitable inhalation device prototype was instrumental to the overall performance of the technology. In vitro testing of the novel large carrier particles yielded emitted fractions in excess of 85%, and overall drug delivery of up to 69% of the nominal dose.Pharmaceutical Science
Hydrostratigraphy and allostratigraphy of the Cenozoic alluvium in the northwestern part of Las Vegas Valley, Clark County, Nevada
This investigation was conducted to determine the location, nature, and boundaries of the most permeable unit within the alluvial aquifer material in Las Vegas Valley. It was prompted by declines in specific capacity of about 90% at the Las Vegas Valley Water District\u27s West Central Well Field. It was hypothesized that the decline in specific capacity resulted from dewatering of the most permeable interval of the alluvium. Lithologic descriptions from wells and aquifer test information were analyzed for geologic and hydrogeologic variability. New information, in the form of detailed unpublished lithologic and hydrologic information, was available from twenty water wells drilled between 1989 and 1994; The geology was defined using allostratigraphic units; Aquifer test and lithologic information was used to define the boundaries of units of differing permeability within the subsurface. These units of differing permeability are the six (6) hydrostratigraphic units introduced in this investigation. The most permeable hydrostratigraphic unit is a distinct 20 to 90 m thick horizon, lying generally above 230 m below land surface. When the production wells were first installed at the West Central Well Field in the 1960\u27s, most of the permeable unit was saturated. In 1993 the potentiometric surface was at or below the bottom of this hydrostratigraphic unit. (Abstract shortened by UMI.)
SpC MS 1688 sc, Bill of Lading for Ninety-three Slaves
Bill of lading dated Oct. 24, 1850 for shipment of ninety-three slaves from Baltimore to New Orleans on the ship John C. Calhoun, master Captain John C. Lowell. The slaves were to be delivered to J.M. Wilson in New Orleans. Document lists names of slaves, their ages and their price.
PDF provides scans of the original document (a printed form completed in handwriting) and a transcript prepared by Special Collections in 2021.
Part of the Francis O\u27Brien Collection purchased in 1968.https://digitalcommons.library.umaine.edu/manuscripts_19th_century/1002/thumbnail.jp
Support for Legislative Term Limitations in California – Group Representation, Partisanship, and Campaign Information
This study uses opinion data to assess the basis of public support for California\u27s term limit initiative (Proposition 140). We test if support was higher among members of demographic groups under-represented in the state\u27s legislature, if support displays a partisan bias, and if campaign contacts are associated with opinions. Ethnic and racial characteristics display little association with support; however women and younger voters were more supportive. Partisanship and campaign effects appear to have played an important role in shaping support for the initiative
Augustana Seniors Fall 1885: Joel L. Haff
Joel L. Haff was a senior at Augustana College, Rock Island, Illinois, in the fall of 1885. His name appears in the college catalog of 1885-1886, along with his birthplace, the year of his birth, and a few other facts. From this start, we researched the genealogy and family history of Joel L. Haff. This paper contains a short biography of Joel, a report on his ancestors, a report on his descendants, and some open questions for further research
Pneumatosis Intestinalis: A Case Report and Approach to Management
Pneumatosis intestinalis (PI), defined as gas within the bowel wall, is an uncommon radiographic sign which can represent a wide spectrum of diseases and a variety of underlying diagnoses. Because its etiology can vary greatly, management of PI ranges from surgical intervention to outpatient observation (see, Greenstein et al. (2007), Morris et al. (2008), and Peter et al. (2003)). Since PI is infrequently encountered, clinicians may be unfamiliar with its diagnosis and management; this unfamiliarity, combined with the potential necessity for urgent intervention, may place the clinician confronted with PI in a precarious medical scenario. We present a case of pneumatosis intestinalis in a patient who posed a particularly challenging diagnostic dilemma for the primary team. Furthermore, we explore the differential diagnosis prior to revealing the intervention offered to our patient; our concise yet inclusive differential and thought process for rapid evaluation may be of benefit to clinicians presented with similar clinical scenarios
Retinal horizontal cells lacking Rb1 sustain persistent DNA damage and survive as polyploid giant cells
The retinoblastoma tumor susceptibility gene, Rb1, is a key regulator of the cell cycle, and mutations in this gene have been found in many human cancers. Prior studies showed that retina-specific knockout of Rb1 in the mouse results in the formation of abnormally large horizontal cells, but the development, fate, and genomic status of these cells remain unknown. In this study, we conditionally inactivate Rb1 in early retinal progenitors and show that the loss of Rb1 leads to the rapid degeneration of most retinal cells except horizontal cells, which persist as giant cells with aberrant centrosome content, DNA damage, and polyploidy/aneuploidy. We observed inappropriate cell cycle entry of Rb1-deficient horizontal cells during the first postnatal weeks, which dropped off abruptly by P30. Despite extensive DNA damage in Rb1-deficient horizontal cells, these cells can still enter mitosis. Adult Rb1-deficient horizontal cells display elevated DNA content (5N–34N) that varied continuously, suggesting the presence of aneuploidy. We also found evidence of supernumerary and disoriented centrosomes in a rare population of mitotic cells in the mutant retinas. Overall our data demonstrate that horizontal cells are a remarkably robust cell type and can survive for months despite extensive DNA damage and elevated genome content
Daily Sleep Quality is Associated with Daily Cognition in Late-Life
Background: Older adults often face sleep disturbance or cognitive decline that goes beyond the scope of normal aging. The present study examined the relationship between self-reported sleep quality and self-reported daytime attention in a community-dwelling sample of older men at the between-persons and within-persons levels of association.
Methods: Thirty-eight participants (M age =75.36 years, SD age =7.51 years, range=66-90 years) completed a twice-daily sleep diary for one week. Sleep quality and attention were assessed using a single-item 0-10 rating scales from the morning diary (“How was the quality of your sleep last night?”) and from the evening diary (“How was your attention today?”). A two-level multilevel model was parameterized with days nested within individuals to examine whether nightly sleep quality predicts an individual’s daily attention rating.
Results: A multilevel model predicting self-reported attention revealed (1) older individuals who reported better sleep quality reported having better daily attention [Beta=0.64, t(248.15)=10.12, p\u3c0.001] and (2) following a day of above-average sleep quality, older individuals experienced above-average attention [Beta=0.16, t(259.79)=2.75, p=.006].
Conclusion: Not only was overall sleep quality associated with self-reported attention, but a good night\u27s sleep was associated with better self-reported next-day attention. Results point to the potential importance of fluctuations in sleep quality for daytime functioning. Interventions aimed at improving nightly sleep consistency may be worth exploring as methods to improve daytime cognitive functioning in older adults.
Support: This work was supported by the Sleep Research Society Foundation/Jazz Pharmaceuticals (001JP13, PI: Dzierzewski) and by the National Institute on Aging of the National Institutes of Health under Award Number K23AG049955 (PI: Dzierzewski), and National Heart Lung and Blood Institute at the National Institutes of Health under award number K24HL143055 (PI: Martin). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or the Department of Veterans Affairs.https://scholarscompass.vcu.edu/gradposters/1089/thumbnail.jp
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