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Alvarado TR, Lee AC, Tomlin B, Schwab P. Evaluation of internal standards for inductively coupled plasma-mass spectrometric analysis of arsenic in soils. J Environ Qual 2022; 51:765-773. [PMID: 35580254 DOI: 10.1002/jeq2.20368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
Arsenic (As) is a common contaminant in soils, and analysis of soils by inductively coupled plasma-mass spectrometry (ICP-MS) is often used to detect As in soil extracts. Internal standards (ISs) are part of ICP-MS analyses to enhance precision and accuracy by compensating for instrument variability; however, an improper choice of IS can result in negative analytical bias. The goal of this study was to develop a protocol for evaluating ISs commonly used in ICP-MS. Three soils of varying clay content and total As were extracted with a dilute electrolyte [0.005 mol L-1 Mg(NO3 )2 ] and an acid digest. Arsenic concentrations were quantified by ICP-MS using typical ISs: 6 Li, 45 Sc, 69 Ga, 89 Y, 103 Rh, 115 In, 159 Tb, and 209 Bi. Standard addition was used as a benchmark for As quantification. The most consistent IS was 115 In. Elevated, naturally occurring concentrations were detected for several of the ISs, particularly in the total digests, emphasizing the necessity for screening soils prior to analysis.
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Affiliation(s)
- Taylor R Alvarado
- North Carolina State Univ., 101 Derieux Place, Raleigh, NC, 27695, USA
| | - Andrew C Lee
- USEPA, 77 West Jackson Boulevard (AR-18J), Chicago, IL, 60604-3507, USA
| | - Bryan Tomlin
- Center for Chemical Characterization, Texas A&M Univ., 3144 TAMU, College Station, TX, 77843-3144, USA
| | - Paul Schwab
- Soil and Crop Sciences, Texas A&M Univ., College Station, TX, 77843-2260, USA
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Pandey A, Dou F, Morgan CLS, Guo J, Deng J, Schwab P. Modeling organically fertilized flooded rice systems and its long-term effects on grain yield and methane emissions. Sci Total Environ 2021; 755:142578. [PMID: 33038809 DOI: 10.1016/j.scitotenv.2020.142578] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 09/18/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The increasing trend of adopting organic fertilization in rice production can impact grain yields and soil methane (CH4) emissions. To simulate these impacts in the absence of long-term field data, a process-based biogeochemical model, Denitrification and Decomposition (DNDC version 9.5) was used. The model was calibrated against a single year greenhouse study and validated using a previously published one-year field trial from 1990, both comparing varying fertilization systems in rice production in southeast Texas, USA. In both the greenhouse and the field studies, lower grain yield and greater soil CH4 emissions were observed in organically fertilized systems. Calibrated model simulations of the greenhouse study correlated with the observed daily CH4 emissions (conventional r2 = 0.87; organic r2 = 0.91) and SOC (r2 = 0.83); but, the model overestimated yield of conventional systems (slope = 1.2) and underestimated yield of organic systems (slope = 0.68). For the field study, agreement between simulated and observed yields and CH4 emissions resulted in slopes close to 1. A simple organic system with urea and straw amendment from the field study was an input available in DNDC whereas the slow release, pelletized organic fertilizer used in the greenhouse study, Nature Safe, was not modeled well by DNDC. The validated model was used to simulate 22 years of rice production and predicted that the differences in yield and CH4 emissions between treatments would diminish with time. In the model simulations, the overall soil health was enhanced when managed with organic fertilization compared to conventional inorganic fertilizers. Model simulations could be improved further by including site-specific calibration of soil organic C, and soil carbon dioxide (CO2) emissions.
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Affiliation(s)
- Aditi Pandey
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA.
| | - Fugen Dou
- Texas A&M AgriLife Research Center at Beaumont, Beaumont, TX 77713, USA
| | | | - Jingqi Guo
- Texas A&M AgriLife Research Center at Beaumont, Beaumont, TX 77713, USA
| | - Jia Deng
- Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH 03824, USA
| | - Paul Schwab
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
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Tahtouh J, Mohtar R, Assi A, Schwab P, Jantrania A, Deng Y, Munster C. Impact of brackish groundwater and treated wastewater on soil chemical and mineralogical properties. Sci Total Environ 2019; 647:99-109. [PMID: 30077859 DOI: 10.1016/j.scitotenv.2018.07.200] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/15/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
The long-term effect of using treated wastewater is not clearly defined: some researchers argue that it is better than freshwater for the soil health; others disapprove, claiming that irrigation with unconventional water resources causes soil degradation. This study assesses the impact of irrigation with non-traditional water on the chemical and mineralogical properties of a calcareous clayey soil from West Texas. The exponential rise in population and the realities of climate change contribute to the global increase in freshwater scarcity: non-conventional water sources, such as treated wastewater (TWW) and brackish groundwater (BGW), offer potentially attractive alternative water resources for irrigated agriculture. For this research, the differences between TWW and BGW were addressed by collecting and analyzing water samples for salt and nutrient content. Soil samples from three horizons (Ap, A, and B) were obtained from three different fields: Rainfed (RF), BGW irrigated, and TWW irrigated. Soil was analyzed for texture, salinity, sodicity, and carbon content. Clay mineralogy of the three different fields was analyzed using the B-horizons. The outcomes from the analysis showed that the BGW from the Lipan aquifer has higher salinity and is harder compared to TWW. Although the exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), and electroconductivity (EC) increased marginally compared to the control soil (RF), the soils were in good health, all the values of interest (SAR < 13, ESP < 15, pH < 8.5, and EC < 4) were low, indicating no sodicity or salinity problems. Smectite, illite, and kaolinite were identified in the three B-horizon samples using bulk X-ray diffraction (XRD). Overall, no major changes were observed in the soil. Thus, TWW and BGW are viable replacements for freshwater irrigation in arid and semi-arid regions.
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Affiliation(s)
- Jeffry Tahtouh
- WEF Nexus Initiative, Texas A&M University, College Station, TX, USA; Water Management and Hydrological Science, Texas A&M University, College Station, TX, USA
| | - Rabi Mohtar
- WEF Nexus Initiative, Texas A&M University, College Station, TX, USA; Zachry Department of Civil Engineering, Texas A&M University, College Station, USA; Department of Biological and Agricultural Engineering, Texas A&M University, College Station, USA; Faculty of Agricultural and Food Sciences, American University of Beirut, Beirut, Lebanon.
| | - Amjad Assi
- Department of Biological and Agricultural Engineering, Texas A&M University, College Station, USA
| | - Paul Schwab
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA
| | - Anish Jantrania
- Texas A&M Agrilife and Extension Center, Texas A&M University, Temple, TX, USA
| | - Youjun Deng
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX, USA
| | - Clyde Munster
- Department of Biological and Agricultural Engineering, Texas A&M University, College Station, USA
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Zhang W, Musante C, White JC, Schwab P, Wang Q, Ebbs SD, Ma X. Bioavailability of cerium oxide nanoparticles to Raphanus sativus L. in two soils. Plant Physiol Biochem 2017; 110:185-193. [PMID: 26754029 DOI: 10.1016/j.plaphy.2015.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 12/22/2015] [Accepted: 12/22/2015] [Indexed: 06/05/2023]
Abstract
Cerium oxide nanoparticles (CeO2 NP) are a common component of many commercial products. Due to the general concerns over the potential toxicity of engineered nanoparticles (ENPs), the phytotoxicity and in planta accumulation of CeO2 NPs have been broadly investigated. However, most previous studies were conducted in hydroponic systems and with grain crops. For a few studies performed with soil grown plants, the impact of soil properties on the fate and transport of CeO2 NPs was generally ignored even though numerous previous studies indicate that soil properties play a critical role in the fate and transport of environmental pollutants. The objectives of this study were to evaluate the soil fractionation and bioavailability of CeO2 NPs to Raphanus sativus L (radish) in two soil types. Our results showed that the silty loam contained slightly higher exchangeable fraction (F1) of cerium element than did loamy sand soil, but significantly lower reducible (F2) and oxidizable (F3) fractions as CeO2 NPs concentration increased. CeO2 NPs associated with silicate minerals or the residue fraction (F4) dominated in both soils. The cerium concentration in radish storage root showed linear correlation with the sum of the first three fractions (r2 = 0.98 and 0.78 for loamy sand and silty loam respectively). However, the cerium content in radish shoots only exhibited strong correlations with F1 (r2 = 0.97 and 0.89 for loamy sand and silty loam respectively). Overall, the results demonstrated that soil properties are important factors governing the distribution of CeO2 NPs in soil and subsequent bioavailability to plants.
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Affiliation(s)
- Weilan Zhang
- Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Craig Musante
- Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06504, USA
| | - Jason C White
- Department of Analytical Chemistry, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06504, USA
| | - Paul Schwab
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Qiang Wang
- Department of Civil and Environmental Engineering, Southern Illinois University, Carbondale, IL 62901, USA
| | - Stephen D Ebbs
- Department of Plant Biology and Center for Ecology, Southern Illinois University, Carbondale, IL 62901, USA
| | - Xingmao Ma
- Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843, USA.
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Affiliation(s)
- Paul Schwab
- Agronomy Department; Kansas State University; Manhattan Kansas
| | - Katherine Banks
- Civil Engineering Department; Kansas State University; Manhattan Kansas
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Martin WA, Lee LS, Schwab P. Antimony migration trends from a small arms firing range compared to lead, copper, and zinc. Sci Total Environ 2013; 463-464:222-228. [PMID: 23810861 DOI: 10.1016/j.scitotenv.2013.05.086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 05/25/2013] [Accepted: 05/28/2013] [Indexed: 06/02/2023]
Abstract
Small arms firing ranges (SAFRs) contain a mixed amount of bullets and bullet fragments accumulated throughout their designed lifetime. Lead-antimony (Pb-Sb) alloy copper (Cu) jacketed bullets are a common modern ammunition used at SAFRs. The impact of bullets with berm material (i.e., soil) generates a heterogeneous distribution of bullets and bullet fragments in the surrounding soil. As bullets and bullet fragments corrode in the berm soil, the migration potential for antimony compared to other metals is quite high. The goal of this study was to evaluate the spatial Sb migration potential from an SAFR as compared to lead, copper, and zinc (Zn) migration from the same SAFR. Berm soil samples were collected along with surface and ground water samples for a preliminary investigation of the Sb migration from an active SAFR. In addition, different aqueous sample preservation techniques were used and evaluated. Soil sample analysis results show the presence of the metals (i.e., Pb, Sb, Cu, and Zn) in the range floor soil samples, indicating the migration of these metals from the berm to the range floor. The groundwater samples indicate that Sb was migrating from the SAFR more readily than the other metals based on the concentration of Sb in the monitoring well farthest from the SAFR berm.
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Affiliation(s)
- W Andy Martin
- U.S. Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, MS, 39180, USA; Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA.
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Gorini C, Raimondi R, Schwab P. Onsager relations in a two-dimensional electron gas with spin-orbit coupling. Phys Rev Lett 2012; 109:246604. [PMID: 23368358 DOI: 10.1103/physrevlett.109.246604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Indexed: 06/01/2023]
Abstract
Theory predicts for the two-dimensional electron gas with only a Rashba spin-orbit interaction a vanishing spin Hall conductivity and at the same time a finite inverse spin Hall effect. We show how these seemingly contradictory results are compatible with the Onsager relations: The latter do hold for spin and particle (charge) currents in the two-dimensional electron gas, although (i) their form depends on the experimental setup and (ii) a vanishing bulk spin Hall conductivity does not necessarily imply a vanishing spin Hall effect. We also discuss the situation in which extrinsic spin orbit from impurities is present and the bulk spin Hall conductivity can be different from zero.
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Affiliation(s)
- C Gorini
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, CNRS and Université de Strasbourg, 23 rue du Loess, BP 43, F-67034 Strasbourg Cedex 2, France
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Lippuner K, Grifone S, Schwenkglenks M, Schwab P, Popp AW, Senn C, Perrelet R. Comparative trends in hospitalizations for osteoporotic fractures and other frequent diseases between 2000 and 2008. Osteoporos Int 2012; 23:829-39. [PMID: 21625882 DOI: 10.1007/s00198-011-1660-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/02/2011] [Indexed: 10/18/2022]
Abstract
UNLABELLED In Switzerland, the number, incidence, and cost of acute hospitalizations for major osteoporotic fractures (MOF) and major cardiovascular events (MCE) increased in both women and men between 2000 and 2008, although the mean length of stay (LOS) was significantly reduced. Similar trend patterns were observed for hip fractures and strokes (decrease) and nonhip fractures and acute myocardial infarctions (increase). INTRODUCTION The purpose of this study was to compare the trends and epidemiological characteristics of hospitalizations for MOF and other frequent diseases between years 2000 and 2008 in Switzerland. METHODS Trends in the number, age-standardized incidence, mean LOS, and cost of hospitalized MOF and MCE (acute myocardial infarction, stroke, and heart failure) were compared in women and men aged ≥ 45 years, based on data from the Swiss Federal Statistical Office. RESULTS Between 2000 and 2008, the incidence of acute hospitalizations for MOF increased by 3.4% in women and 0.3% in men. In both sexes, a significant decrease in hip fractures (-15.0% and -11.0%) was compensated by a concomitant, significant increase in nonhip fractures (+24.8% and +13.8%). Similarly, the incidence of acute hospitalizations for MCE increased by 4.4% in women and 8.2% in men, as an aggregated result from significantly increasing acute myocardial infarctions and significantly decreasing strokes. While the mean LOS in the acute inpatient setting decreased almost linearly between years 2000 and 2008 in all indications, the inpatient costs increased significantly (p < 0.001) for MOF (+30.1% and +42.7%) and MCE (+22.6% and +47.1%) in women and men, respectively. CONCLUSIONS Between years 2000 and 2008, the burden of hospitalized osteoporotic fractures to the Swiss healthcare system has continued to increase in both sexes. In women, this burden was significantly higher than that of MCE and the gap widened over time.
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Affiliation(s)
- K Lippuner
- Osteoporosis Policlinic, Inselspital, Bern University Hospital and University of Bern, CH-3010 Bern, Switzerland.
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Lippuner K, Popp AW, Schwab P, Gitlin M, Schaufler T, Senn C, Perrelet R. Fracture hospitalizations between years 2000 and 2007 in Switzerland: a trend analysis. Osteoporos Int 2011; 22:2487-97. [PMID: 21153020 DOI: 10.1007/s00198-010-1487-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
UNLABELLED In Switzerland, the total number and incidence of hospitalizations for major osteoporotic fractures increased between years 2000 and 2007, while hospitalizations due to hip fracture decreased. The cost impact of shorter hospital stays was offset by the increasing cost per day of hospitalization. INTRODUCTION The aim of the study was to establish the trends and epidemiological characteristics of hospitalizations for major osteoporotic fractures (MOF) between years 2000 and 2007 in Switzerland. METHODS Sex- and age-specific trends in the number and crude and age-standardized incidences of hospitalized MOF (hip, clinical spine, distal radius, and proximal humerus) in women and men aged ≥45 years were analyzed, together with the number of hospital days and cost of hospitalization, based on data from the Swiss Federal Statistical Office hospital database and population statistics. RESULTS Between 2000 and 2007, the absolute number of hospitalizations for MOF increased by 15.9% in women and 20.0% in men, mainly due to an increased number of non-hip fractures (+37.7% in women and +39.7% in men). Hospitalizations for hip fractures were comparatively stable (-1.8% in women and +3.3% in men). In a rapidly aging population, in which the number of individuals aged ≥45 years grew by 11.1% (women) and 14.6% (men) over the study period, the crude and age-standardized incidences of hospitalizations decreased for hip fractures and increased for non-hip MOF, both in women and men. The length of hospital stay decreased for all MOF in women and men, the cost impact of which was offset by an increase in the daily costs of hospitalization. CONCLUSIONS Between years 2000 and 2007, hospitalizations for MOF continued to increase in Switzerland, driven by an increasing number and incidence of hospitalizations for non-hip fractures, although the incidence of hip fractures has declined.
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Affiliation(s)
- K Lippuner
- Osteoporosis Policlinic, Inselspital, Bern University Hospital, University of Bern, 3010, Bern, Switzerland.
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Bartels T, Cameretti L, Haensel R, Krüger KM, Schwab P, Seidensticker P. Ionische Flüssigkeiten als neue Hochleistungsschmiermittel für Windkraftgetriebe. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201050189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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11
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Chotorlishvili L, Schwab P, Berakdar J. Dynamic switching of the magnetization in a driven molecular nanomagnet. J Phys Condens Matter 2010; 22:036002. [PMID: 21386300 DOI: 10.1088/0953-8984/22/3/036002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We study the magnetization dynamics of a single molecular nanomagnet driven by static and variable magnetic fields within a classical treatment. The underlying analysis is valid for a regime where the energy is definitely lower than the anisotropy barrier, but still a substantial number of states are excited. We find the phase space to contain a separatrix line. Solutions far from it are oscillatory whereas the separatrix solution is of a soliton type. States near the separatrix are extremely sensitive to small perturbations, a fact that we utilize in obtaining dynamically induced magnetization switching. A new type of magnetization switching is proposed.
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Affiliation(s)
- L Chotorlishvili
- Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany
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Seiler M, Vogt M, Bröcker S, Schwab P, Kühn A, Ziegler F. Absorptionkältemaschinen: Verfahrenssimulation mit neuen Arbeitspaaren basierend auf ionischen Flüssigkeiten. CHEM-ING-TECH 2009. [DOI: 10.1002/cite.200950438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hoff A, Krüger KM, Kobus A, Seiler M, Schwab P, Predel T, Schlücker E. Advanced Fluids für ingenieurtechnische Anwendungen. CHEM-ING-TECH 2008. [DOI: 10.1002/cite.200750468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schwab P, Zhu D, Banks MK. Heavy metal leaching from mine tailings as affected by organic amendments. Bioresour Technol 2007; 98:2935-41. [PMID: 17157002 DOI: 10.1016/j.biortech.2006.10.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 10/02/2006] [Accepted: 10/03/2006] [Indexed: 05/12/2023]
Abstract
A column experiment was conducted to investigate Zn, Cd, and Pb leaching from mine tailings as affected by the addition of organic amendments. Composted yard waste, composted cattle manure, and cattle manure aged for one month increased heavy metal leaching from mine tailings when compared to an unamended control. Aged cattle manure and composted cattle manure significantly increased Zn concentration in the leachate. The maximum Zn concentration in leachate from the manure-amended treatments was as high as 3.7 mg/L, whereas Zn concentrations from the control were less than 0.7 mg/L. All organic amendments increased Cd leachate concentrations. The presence of aged cattle manure greatly increased Pb concentrations in the leachate from less than 10 microg/L for the control treatment to higher than 60 microg/L. Lead concentration in leachate was positively correlated with inorganic carbon, total organic carbon, total carbon and bicarbonate. Although organic amendments increased Zn, Cd, and Pb leaching when compared with the control treatment, Zn concentrations were lower than the 5 mg/L secondary drinking water standard, and Pb concentrations were only minimally higher than the 15 microg/L drinking water standard. Cadmium concentrations from manure treatments exceeded the 5 microg/L drinking water standard but only during the first 15 days. Organic amendments may encourage establishment of vegetation in mining areas that may minimize heavy metal contamination through runoff and erosion. However, increased risk due to heavy metal leaching in the presence of organic amendments should be carefully considered.
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Affiliation(s)
- Paul Schwab
- Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA
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15
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Seiler M, Schwab P, Kobus A. Das Potenzial ionischer Flüssigkeiten für Absorptionskältemaschinen. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200750146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Zierau O, Kretschmar G, Schwab P, Metz P, Vollmer G. Time dependency of uterine effects of 8-prenylnaringenin and 6-dimethylallylnaringenin in vivo. Exp Clin Endocrinol Diabetes 2006. [DOI: 10.1055/s-2006-932973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernat JL, D'Alessandro AM, Port FK, Bleck TP, Heard SO, Medina J, Rosenbaum SH, Devita MA, Gaston RS, Merion RM, Barr ML, Marks WH, Nathan H, O'connor K, Rudow DL, Leichtman AB, Schwab P, Ascher NL, Metzger RA, Mc Bride V, Graham W, Wagner D, Warren J, Delmonico FL. Report of a National Conference on Donation after cardiac death. Am J Transplant 2006; 6:281-91. [PMID: 16426312 DOI: 10.1111/j.1600-6143.2005.01194.x] [Citation(s) in RCA: 356] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States.
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Spriggs T, Banks MK, Schwab P. Phytoremediation of polycyclic aromatic hydrocarbons in manufactured gas plant-impacted soil. J Environ Qual 2005; 34:1755-62. [PMID: 16151227 DOI: 10.2134/jeq2004.0399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Contamination of soil by hazardous substances poses a significant threat to human, environmental, and ecological health. Cleanup of the contaminants using destructive, invasive technologies has proven to be expensive and more importantly, often damaging to the natural resource properties of the soil, sediment, or aquifer. Phytoremediation is defined as the cleanup of contaminated sites using plants. There has been evidence of enhanced polycyclic aromatic hydrocarbons (PAHs) degradation in rhizosphere soils for a limited number of plants. However, research focusing on the degradation of PAHs in the rhizosphere of trees is lacking. The objective of this study was to assess the potential use of trees to enhance degradation of PAHs located in manufactured gas plant-impacted soils. In greenhouse studies with intact soil cores, acenaphthene, anthracene, fluoranthene, naphthalene, and phenanthrene decreased significantly (p < 0.05) in green ash (Fraxinus pennsylvanica Marshall) and hybrid poplar (Populus deltoides x P. nigra DN 34) phytoremediation treatments when compared to the unplanted soil control. Increases in PAH microbial degraders in rhizosphere soil were observed when compared to unvegetated soil controls. In addition, the rate of degradation or biotransformation of PAHs was greatest for soils with black willow (Salix nigra Marshall), followed by poplar, ash, and the unvegetated controls. These results support the hypothesis that a variety of plants can enhance the degradation of target PAHs in soil.
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Affiliation(s)
- Thomas Spriggs
- School of Civil Engineering, Purdue University, West Lafayette, IN 47907, USA
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Eckern U, Schwab P, Ambegaokar V. Comment on "Magnetic response of disordered metallic rings: large contributions of far levels". Phys Rev Lett 2004; 93:209701-209702. [PMID: 15600983 DOI: 10.1103/physrevlett.93.209701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2004] [Indexed: 05/24/2023]
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20
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Zierau O, Morrissey C, Watson RW, Schwab P, Kolba S, Metz P, Vollmer G. Substitution of positions 6 and 8 lead to an increased anti-androgenic activity of the phytoestrogen naringenin. Exp Clin Endocrinol Diabetes 2004. [DOI: 10.1055/s-2004-819074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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21
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Banks MK, Schwab P, Liu B, Kulakow PA, Smith JS, Kim R. The effect of plants on the degradation and toxicity of petroleum contaminants in soil: a field assessment. Adv Biochem Eng Biotechnol 2003; 78:75-96. [PMID: 12674399 DOI: 10.1007/3-540-45991-x_3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A field project located at the US Naval Base at Port Hueneme, California was designed to evaluate changes in contaminant concentrations and toxicity during phytoremediation. Vegetated plots were established in petroleum (diesel and heavy oil) contaminated soil and were evaluated over a two-year period. Plant species were chosen based on initial germination studies and included native California grasses. The toxicity of the impacted soil in vegetated and unvegetated plots was evaluated using Microtox, earthworm, and seed germination assays. The reduction of toxicity was affected more by contaminant aging than the establishment of plants. However, total petroleum hydrocarbon concentrations were lower by the end of the study in the vegetated plots when compared to the unvegetated soil. Although phytoremediation is an effective approach for cleaning-up of petroleum contaminated soil, a long-term management plan is required for significant reductions in contaminant concentrations.
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Affiliation(s)
- M K Banks
- School of Civil Engineering, Purdue University, West Lafayette, IN 47906, USA.
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22
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Affiliation(s)
- G D Raffel
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Siciliano SD, Fortin N, Mihoc A, Wisse G, Labelle S, Beaumier D, Ouellette D, Roy R, Whyte LG, Banks MK, Schwab P, Lee K, Greer CW. Selection of specific endophytic bacterial genotypes by plants in response to soil contamination. Appl Environ Microbiol 2001; 67:2469-75. [PMID: 11375152 PMCID: PMC92896 DOI: 10.1128/aem.67.6.2469-2475.2001] [Citation(s) in RCA: 291] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plant-bacterial combinations can increase contaminant degradation in the rhizosphere, but the role played by indigenous root-associated bacteria during plant growth in contaminated soils is unclear. The purpose of this study was to determine if plants had the ability to selectively enhance the prevalence of endophytes containing pollutant catabolic genes in unrelated environments contaminated with different pollutants. At petroleum hydrocarbon contaminated sites, two genes encoding hydrocarbon degradation, alkane monooxygenase (alkB) and naphthalene dioxygenase (ndoB), were two and four times more prevalent in bacteria extracted from the root interior (endophytic) than from the bulk soil and sediment, respectively. In field sites contaminated with nitroaromatics, two genes encoding nitrotoluene degradation, 2-nitrotoluene reductase (ntdAa) and nitrotoluene monooxygenase (ntnM), were 7 to 14 times more prevalent in endophytic bacteria. The addition of petroleum to sediment doubled the prevalence of ndoB-positive endophytes in Scirpus pungens, indicating that the numbers of endophytes containing catabolic genotypes were dependent on the presence and concentration of contaminants. Similarly, the numbers of alkB- or ndoB-positive endophytes in Festuca arundinacea were correlated with the concentration of creosote in the soil but not with the numbers of alkB- or ndoB-positive bacteria in the bulk soil. Our results indicate that the enrichment of catabolic genotypes in the root interior is both plant and contaminant dependent.
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Affiliation(s)
- S D Siciliano
- Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, and Fisheries and Oceans Canada, Dartmouth, Nova Scotia
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24
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Siciliano SD, Fortin N, Mihoc A, Wisse G, Labelle S, Beaumier D, Ouellette D, Roy R, Whyte LG, Banks MK, Schwab P, Lee K, Greer CW. Selection of specific endophytic bacterial genotypes by plants in response to soil contamination. Appl Environ Microbiol 2001; 67:2469-2475. [PMID: 11375152 DOI: 10.1128/aem.67.6.2469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
Plant-bacterial combinations can increase contaminant degradation in the rhizosphere, but the role played by indigenous root-associated bacteria during plant growth in contaminated soils is unclear. The purpose of this study was to determine if plants had the ability to selectively enhance the prevalence of endophytes containing pollutant catabolic genes in unrelated environments contaminated with different pollutants. At petroleum hydrocarbon contaminated sites, two genes encoding hydrocarbon degradation, alkane monooxygenase (alkB) and naphthalene dioxygenase (ndoB), were two and four times more prevalent in bacteria extracted from the root interior (endophytic) than from the bulk soil and sediment, respectively. In field sites contaminated with nitroaromatics, two genes encoding nitrotoluene degradation, 2-nitrotoluene reductase (ntdAa) and nitrotoluene monooxygenase (ntnM), were 7 to 14 times more prevalent in endophytic bacteria. The addition of petroleum to sediment doubled the prevalence of ndoB-positive endophytes in Scirpus pungens, indicating that the numbers of endophytes containing catabolic genotypes were dependent on the presence and concentration of contaminants. Similarly, the numbers of alkB- or ndoB-positive endophytes in Festuca arundinacea were correlated with the concentration of creosote in the soil but not with the numbers of alkB- or ndoB-positive bacteria in the bulk soil. Our results indicate that the enrichment of catabolic genotypes in the root interior is both plant and contaminant dependent.
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Affiliation(s)
- S D Siciliano
- Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, and Fisheries and Oceans Canada, Dartmouth, Nova Scotia
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25
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Affiliation(s)
- P Schwab
- Division of Internal Medicine, University of Texas Health Science Center at Houston, USA
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26
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Abstract
A series of carbenerhodium(I) complexes of the general composition [(eta5-C5H5)Rh(=CRR')(L)] (2a-2i) with R = R'= aryl and L = SbiPr3 or PR3 has been prepared from the square-planar precursors trans-[RhCl(=CRR')(L)2] and NaC5H5 in excellent yields. Reaction of the triisopropylsibane derivative 2a. which contains a rather labile Rh-Sb bond, with CO, PMe3, and CNR (R = Me, CH2Ph, tBu) leads to the displacement of the SbiPr3 ligand and affords the substitution products [(eta5-C5H5)Rh(=CPh2)(L)] (3-7). In contrast, treatment of the triisopropylphosphane compound 2c with CO and CNtBu leads to the cleavage of the Rh=CPh2 bond and gives besides [(eta5-C5H5)Rh(PiPr3)(L)] (10, 12) by metal-assisted C-C coupling diphenylketene Ph2C=C=O (11) or the corresponding imine Ph2C=C=NtBu (13). While the reaction of 2a, c with C2H4 yields [(eta5-C5H5)Rh(C2H4)(L)] (14, 15) and the trisubstituted olefin Ph2C=CHCH3 (16), treatment of 2a, c with RN3 leads to the cleavage of both the Rh-EiPr3 and Rh=CPh2 bonds and gives the chelate complexes [(eta5-C5H5)Rh(kappa2-RNNNNR)] (19, 20). The substitution products 3 (L=CO) and 4 (L= PMe3) react with an equimolar amount of sulfur or selenium by addition of the chalcogen to the Rh=CPh2 bond to generate the complexes [(eta5-C5H5)Rh(kappa2-ECPh2)(L)] (21-24) with thio- or selenobenzophenone as ligand. Similarly, treatment of 3 with CuCl affords the unusual 1:2 adduct [(eta5-C5H5)(CO)Rh(mu-CPh2)(CuCl)2] (25), which reacts with NaC5H5 to form [(eta5-C5H5)(CO)Rh(muCPh2)Cu(eta5-C5H5)] (26). The molecular structures of 3 and 22 have been determined by X-ray crystallography.
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Affiliation(s)
- H Werner
- Institut für Anorganische Chemie der Universität Würzburg, Germany.
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Schwab P, Wolf J, Mahr N, Steinert P, Herber U, Werner H. The bridging function of an apparently nonbridging ligand: dinuclear rhodium complexes with Rh(mu-SbR3)Rh as a molecular unit. Chemistry 2000; 6:4471-8. [PMID: 11192079 DOI: 10.1002/1521-3765(20001215)6:24<4471::aid-chem4471>3.0.co;2-d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Novel dinuclear rhodium complexes of the general composition [Rh2Cl2(mu-CRR')2(mu-SbiPr3)] (4-6) were prepared by thermolysis of the mononuclear precursors trans-[RhCl(=CRR')(SbiPr3)2] in excellent yield. The X-ray crystal structure analysis of 4 (R = R' = Ph) confirms the symmetrical bridging position of the stibane ligand. Related compounds [Rh2Cl2(mu-CPh2)(mu-CRR')(mu-SbiPr3)] (7, 8) with two different carbene units were obtained either from trans-[RhCl(=CPh2)(SbiPr3)2] (1) and RR'CN2 or by a conproportionation of 4 and 5 (R = R' = p-Tol) or 4 and 6 (R= Ph, R' = p-Tol), respectively. While CO reacts with 4 to give the polymeric product [[RhCl(CPh2)(CO)]n] (9), tert-butyl isocyanide replaces the bridging stibane and yields [Rh2Cl2(mu-CPh2)2(mu-CNtBu)] (10). The reaction of 4 with tertiary phosphanes PR3 leads to complete bridge cleavage and affords the mononuclear compounds trans-[RhCl(=CPh2)(PR3)2] (11-15). In contrast, treatment of 4 with SbMe3 and SbEt3 yields the related triply bridged complexes [Rh2Cl2(mu-CPh2)2(mu-SbR3)] (16, 17) by substitution of SbiPr3 for the smaller stibanes. The displacement of the chloro ligands in 4-6 and 10 by n5-cyclopentadienyl gives the dinuclear complexes [(n5-C5H5)2Rh2(mu-CRR')2] (18-20) and [(n5-C5H5)2Rh2(mu-CPh2)2(mu-CNtBu)] (21), of which 18 (R = R' = Ph) was characterized crystallographically.
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Affiliation(s)
- P Schwab
- Institut für Anorganische Chemie der Universität Würzburg, Germany
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28
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Abstract
A growing body of evidence suggests that T lymphocytes play an important role in initiating and maintaining the inflammatory process characteristic of the human leukocyte antigen (HLA)-B27-associated spondyloarthropathies. T cells seem to be involved in the primary defense reaction against arthritis-triggering gram-negative bacteria at the site of extra-articular infection, in determining the systemic cytokine pattern, in the recirculation process between gut mucosa and the joint, and in mediating secondary autoimmune joint inflammation. The factors involved in disease chronicity (namely in ankylosing spondylitis and psoriatic arthritis) are still unknown. Autoreactive T cells may contribute to this process by recognition of cross-reactive self-epitopes (ie, molecular mimicry between bacterial and self-antigens). Autoreactive T cells may as well be inappropriately upregulated by bacterial superantigens, or by local inflammatory reactions leading to the uncovering of former cryptic self-epitopes. In this paper, we review recent studies on peripheral blood and synovial T cells in patients with reactive arthritis, enteropathic spondyloarthropathy, psoriatic arthritis, and ankylosing spondylitis.
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Affiliation(s)
- E Märker-Hermann
- Department of Internal Medicine, Johannes Gutenberg-University of Mainz, Langenbeckstr. 1, D - 55101 Mainz, Germany.
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29
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Schwab P, Castellani C. Comment on "Metal-insulator transition of disordered interacting electrons". Phys Rev Lett 2000; 84:4779. [PMID: 10990796 DOI: 10.1103/physrevlett.84.4779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/1999] [Indexed: 05/23/2023]
Affiliation(s)
- P Schwab
- Institut fur Physik, Universitat Augsburg D-86135 Augsburg, Germany
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Hurlimann S, Dür S, Schwab P, Varga L, Mazzucchelli L, Brand R, Halter F. Effects of Helicobacter pylori on gastritis, pentagastrin-stimulated gastric acid secretion, and meal-stimulated plasma gastrin release in the absence of peptic ulcer disease. Am J Gastroenterol 1998; 93:1277-85. [PMID: 9707051 DOI: 10.1111/j.1572-0241.1998.409_x.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE There is strong evidence accumulating that chronic infection with Helicobacter pylori (H. pylori) interferes with inhibitory pathways of the regulation of acid secretion. The increase in maximum acid output (MAO), and the increase in the sensitivity of the parietal cell to gastrin commonly observed in patients suffering from duodenal ulcer disease (DU), however, remains largely unexplained. Insufficient evidence is available concerning how these parameters are influenced by H. pylori infection in patients not suffering from peptic ulcer disease (PUD) and how they are related to H. pylori-induced gastritis. The aim of this study was to compare basal gastric acid secretion (BAO), MAO, and the sensitivity of the parietal cell to gastrin in H. pylori-positive and H. pylori-negative patients not suffering from PUD, and to study the relationship with their individual postprandial gastrin release and the degree of gastric antral and corpus gastritis. METHODS H. pylori status was assessed by CLO test and histology (two biopsies each from the antrum and the corpus) in 14 H. pylori-positive and 16 H. pylori-negative nonulcer patients of comparable age, weight and gender. Gastritis score was assessed by a pathologist, who was unaware of the acid secretory data. Following determination of BAO, the relation of pentagastrin and gastric acid secretion was established with a cumulative pentagastrin dose response curve for the dose range 0.03-6.0 microg/kg(-1) h(-1) and MAO (Vmax) and pentagastrin sensitivity (ED50) were determined. Basal and postprandial gastrin release was measured by radioimmunoassay. RESULTS There was a significant higher gastritis score in the H. pylori-positive compared with the H. pylori-negative subjects. The dose response curves of the pentagastrin stimulated gastric acid secretion were not different between H. pylori-positive and H. pylori-negative groups. No correlation was seen between the gastritis score, basal acid output (BAO) peak acid output (PAO), maximum acid output (MAO), ED50 values and the plasma gastrin values. There was, however, a considerable larger variation of the PAO and MAO data of the H. pylori-infected subjects and >50% of the respective data was above or below the relatively low range of the respective values of the noninfected subjects. CONCLUSIONS H. pylori-induced gastritis does not regularly enhance maximum acid output in nonulcer patients, nor does it modify the sensitivity of the parietal cell to gastrin. H. pylori infection is thus unlikely to be directly responsible for an increase of these parameters in DU disease. Our data support, however, the concept that chronic H. pylori infection can either enhance or attenuate maximum acid secretory capacity in certain subgroups of patients.
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Affiliation(s)
- S Hurlimann
- Gastrointestinal Unit, Inselspital, Berne, Switzerland
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31
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Fred HL, Schwab P. Case in point. Prostatic stones. Hosp Pract (1995) 1998; 33:184. [PMID: 9484303 DOI: 10.1080/21548331.1998.11443644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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32
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Affiliation(s)
- L M Valdez
- Center for the Study of Emerging and Reemerging Pathogens, Department of Internal Medicine, The University of Texas Medical School at Houston 77030, USA
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Schwab P. FDA regulation of liquid chemical germicides and medical device cleaners. Exec Housekeep Today 1995; 16:21-2; quiz 23. [PMID: 10143008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- P Schwab
- Calgon Vestal Laboratories, St Louis, MO 63166, USA
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Abstract
The new health care environment--centered on patients, focused on health, and managed by generalists--requires new competencies for the generalist physician. Among these are knowledge and skills for the continuous improvement of health care. In many areas, generalist physicians already use quality improvement methods and principles to improve the health and health care of their communities. Efforts to teach medical students and residents to improve quality continuously in health care are beginning. Early lessons are: (1) quality improvement is most effectively learned in the context of real work; (2) initial emphasis must be on the basics; (3) the focus is on the needs of those we serve; (4) interdisciplinary skills are essential and best learned during clinical training; and (5) the best learning environment for future generalist physicians, one which results in optimism about the future and the ability to make things better, is an environment that is continuously improving.
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Affiliation(s)
- L A Headrick
- Case Western Reserve University, Cleveland, OH 44109
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Lang W, Heine G, Schwab P, Wang XZ, Bäuerle D. Paraconductivity and excess Hall effect in epitaxial YBa2Cu3O7 films induced by superconducting fluctuations. Phys Rev B Condens Matter 1994; 49:4209-4217. [PMID: 10011319 DOI: 10.1103/physrevb.49.4209] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Schalk RM, Hosseinali GS, Weber HW, Proyer S, Schwab P, Bäuerle D, Gründorfer S. Temperature dependence of the pinning potential in YBa2Cu3O7-x superconductors. Phys Rev B Condens Matter 1994; 49:3511-3519. [PMID: 10011216 DOI: 10.1103/physrevb.49.3511] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Abstract
A learning environment where students may negotiate with the course directors on the objectives and contents of a course, and where the teachers from pre-stated teaching and pedagogical obligations, may also negotiate with the students on what realistic demands they can meet when adjusting to individual students' needs, could be regarded as a set-up where learning by mutual commitment takes place. In order to support and to elaborate on reported experiences from using contracts as a learning device (Solomon, 1992), experiences gained from the Medical School of Witten/Herdecke, Germany, will be presented.
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40
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Affiliation(s)
- F. Lawrence Clare
- Director of the Health Resources and Services Administration's (HRSA) Office of Graduate Medical Education and Data Analysis, Division of Medicine
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41
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Schwab P. [Simplified graphic representation of the evolution of articular function]. Ann Pediatr (Paris) 1983; 30:611-2. [PMID: 6638812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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