| 1. |
- Abd Ali, Ziad T., et al.
(författare)
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Predominant mechanisms for the removal of nickel metal ion from aqueous solution using cement kiln dust
- 2020
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Ingår i: Journal of Water Process Engineering. - : Elsevier BV. - 2214-7144. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- The experimental methodology achieved in the present study signified that the adsorption and precipitation were main mechanisms occurred together in the removal of nickel from aqueous solution by sorption using cement kiln dust (CKD) byproduct as sorbent. Finding the contribution of each mechanism in the removal process and derivation an analytical model for finding the portion of precipitation were the focal points of this work. Results proved that pure precipitation was increased with the increase of CKD dosage and metal concentration where total removal (adsorption-precipitation) ranged from 45 to 100%. The SEM micrographs of the CKD sorbent before and after sorption process certified that there was crystal precipitates on the surface of the CKD. Also, these graphs in combination with FT-IR tests proved that [Ni(OH2)n]+2 (n=4-6) species were bonded with CKD and insoluble hydroxide species may be precipitated onto the CaO surfaces by co-precipitation, while K–O, Si-O and Ca-O groups enhanced the adsorption mechanism.
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| 2. |
- Buggert, Marcus, et al.
(författare)
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Limited immune surveillance in lymphoid tissue by cytolytic CD4+ T cells during health and HIV disease
- 2018
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7374. ; 14:4
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Tidskriftsartikel (refereegranskat)abstract
- CD4+ T cells subsets have a wide range of important helper and regulatory functions in the immune system. Several studies have specifically suggested that circulating effector CD4+ T cells may play a direct role in control of HIV replication through cytolytic activity or autocrine β-chemokine production. However, it remains unclear whether effector CD4+ T cells expressing cytolytic molecules and β-chemokines are present within lymph nodes (LNs), a major site of HIV replication. Here, we report that expression of β-chemokines and cytolytic molecules are enriched within a CD4+ T cell population with high levels of the T-box transcription factors T-bet and eomesodermin (Eomes). This effector population is predominately found in peripheral blood and is limited in LNs regardless of HIV infection or treatment status. As a result, CD4+ T cells generally lack effector functions in LNs, including cytolytic capacity and IFNγ and β-chemokine expression, even in HIV elite controllers and during acute/early HIV infection. While we do find the presence of degranulating CD4+ T cells in LNs, these cells do not bear functional or transcriptional effector T cell properties and are inherently poor to form stable immunological synapses compared to their peripheral blood counterparts. We demonstrate that CD4+ T cell cytolytic function, phenotype, and programming in the peripheral blood is dissociated from those characteristics found in lymphoid tissues. Together, these data challenge our current models based on blood and suggest spatially and temporally dissociated mechanisms of viral control in lymphoid tissues.
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| 3. |
- Eriksson, Olof, et al.
(författare)
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On the use of [F-18]DOPA as an imaging biomarker for transplanted islet mass
- 2014
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Ingår i: Annals of Nuclear Medicine. - : Springer Science and Business Media LLC. - 0914-7187 .- 1864-6433. ; 28:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- AimIslet transplantation is being developed as a potential cure for patients with type 1 diabetes. There is a need for non-invasive imaging techniques for the quantification of transplanted islets, as current transplantation sites are associated with a substantial loss of islet viability. The dopaminergic metabolic pathway is present in the islets; therefore, we propose Fluorine-18 labeled l-3,4-dihydroxyphenylalanine ([F-18]DOPA) as a biomarker for transplanted islet mass.MethodsThe expression of enzymes involved in the dopaminergic metabolic pathway was investigated in both native and transplanted human islets. The specific uptake of [F-18]DOPA in islets and immortalized beta cells was studied in vitro by selective blocking of dopa decarboxylase (DDC). Initial in vivo PET imaging of viable subcutaneous human islets was performed using [F-18]DOPA.ResultsDDC and vesicular monoamine transporter 2 are co-localized with insulin in the native human pancreas, and the expression is retained after transplantation. Islet uptake of the [F-18]DOPA could be modulated by inhibiting DDC, indicating that the uptake followed the normal dopaminergic metabolic pathway. In vivo imaging revealed [F-18]DOPA uptake at the site of the functional islet graft. Based on the in vitro and in vivo results presented in this study, we propose to further validate [F-18]DOPA-PET as a sensitive imaging modality for imaging extrahepatically transplanted islets.
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| 4. |
- Faisal, Ayad A.H., et al.
(författare)
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Using different materials as a permeable reactive barrier for remediation of groundwater contaminated with landfill’s leachate
- 2020
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Ingår i: Desalination and Water Treatment. - : Desalination Publications. - 1944-3994 .- 1944-3986. ; 175, s. 152-163
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the utilization of the waterworks sludge by-product that generated from water supply treatment plant for the remediation of simulated groundwater contaminated with leachate spilled from the sanitary landfill by permeable reactive barrier (PRB) technology. Batch sorption experiments were conducted for describing the interaction between the acetogenic phase (pH=5.5±0.1) of leachate contaminated with cadmium (Cd(II)), ammonia nitrogen (NH3–N) or dissolved organic matter (COD) and waterworks sludge. Also, conventional sorbents such as the activated carbon and amberlite ion-exchange resin were tested to evaluate their ability in compar-ison with waterworks sludge in the remediation process. Results proved that the Langmuir model describes well the sorption data with maximum sorption capacities of 5.634, 14.908 and 3.938mg/g for Cd(II) onto sludge, NH3–N onto resin and COD onto activated carbon, respectively. The batch and column tests signified that the sludge, resin, and carbon can be used for removing Cd(II), NH3–N, and COD, respectively. The multi-layered bed of sorbents under consideration has a remarkable ability in the remediation of a leachate contaminated with Cd(II), NH3–N, and COD. Finally, the Yan model is more representative than Thomas and Belter models for characterization of the contaminants propagation in the column packed with single sorbent.
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| 5. |
- Hering, Bernhard J., et al.
(författare)
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Phase 3 Trial of Transplantation of Human Islets in Type 1 Diabetes Complicated by Severe Hypoglycemia
- 2016
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 39:7, s. 1230-1240
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Impaired awareness of hypoglycemia (IAH) and severe hypoglycemic events (SHEs) cause substantial morbidity and mortality in patients with type 1 diabetes (T1D). Current therapies are effective in preventing SHEs in 50-80% of patients with IAH and SHEs, leaving a substantial number of patients at risk. We evaluated the effectiveness and safety of a standardized human pancreatic islet product in subjects in whom IAH and SHEs persisted despite medical treatment. RESEARCH DESIGN AND METHODS This multicenter, single-arm, phase 3 study of the investigational product purified human pancreatic islets (PHPI) was conducted at eight centers in North America. Forty-eight adults with T1D for >5 years, absent stimulated C-peptide, and documented IAH and SHEs despite expert care were enrolled. Each received immunosuppression and one or more transplants of PHPI, manufactured on-site under good manufacturing practice conditions using a common batch record and standardized lot release criteria and test methods. The primary end point was the achievement of HbA(1c) <7.0% (53 mmol/mol) at day 365 and freedom from SHEs from day 28 to day 365 after the first transplant. RESULTS The primary end point was successfully met by 87.5% of subjects at 1 year and by 71% at 2 years. The median HbA(1c) level was 5.6% (38 mmol/mol) at both 1 and 2 years. Hypoglycemia awareness was restored, with highly significant improvements in Clarke and HYPO scores (P > 0.0001). No study-related deaths or disabilities occurred. Five of the enrollees (10.4%) experienced bleeds requiring transfusions (corresponding to 5 of 75 procedures), and two enrollees (4.1%) had infections attributed to immunosuppression. Glomerular filtration rate decreased significantly on immunosuppression, and donor-specific antibodies developed in two patients. CONCLUSIONS Transplanted PHPI provided glycemic control, restoration of hypoglycemia awareness, and protection from SHEs in subjects with intractable IAH and SHEs. Safety events occurred related to the infusion procedure and immunosuppression, including bleeding and decreased renal function. Islet transplantation should be considered for patients with T1D and IAH in whom other, less invasive current treatments have been ineffective in preventing SHEs.
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| 6. |
- Jing, Wang, et al.
(författare)
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System Dynamics Modeling Strategy for Civil Construction Projects : The Concept of Successive Legislation Periods
- 2019
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Ingår i: Symmetry. - : MDPI. - 2073-8994. ; 11:5, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Cost and time performance are considered to be the most important aspects in the construction industry. The exceptional conditions that took place in Iraq since the beginning of the third millennia had a huge vicious impact on the cost and time performance of local constructionprojects. This may represent the principal motivation for the local authorities to enact some four successive legislations in order to control the performance of the construction industry. In this research, an evaluation is made to the cost and time performance of local construction projects and their variation due to the multiple changes in the internal factors that affect project performance,and changes in the surrounding events include legislative, economic, and security environment during the period that lasted from 2003 to 2014. Data is collected from 30 governmental projects to conduct the evaluation. A comprehensive questionnaire is performed to estimate a quantitative value for the impact of several factors that concern both the owner and the contractor, with special consideration to their variation through the successive legislation periods. These estimates are, in turn, utilized in a system dynamics model, in which the project development process is simulated.The final cost and duration changes in the project are accumulated in the form of stocks to give an indication of the cost and time performance of the project. The developed model returned a progressive reduction of 10.9% for the change in project cost and 135.37% for the change in project schedule throughout the eleven years period.
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| 7. |
- Kadhum, Safaa A., et al.
(författare)
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Microplastic Contamination of Surface Sediment of Euphrates River, Iraq : A Preliminary Study
- 2020
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Ingår i: Journal of Physics: Conference Series. - : Institute of Physics (IOP). - 1742-6588.
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Konferensbidrag (refereegranskat)abstract
- Microplastics pollutants in sediment have been notified in freshwater and estuaries from different countries. However, microplastics abundance, distribution, and polymer types in surface sediment from Euphrates River were reported for the first time. Microplastics were found in all sediment sites along the river, and abundance ranging from 29.6 to 120.0 particles/kg dry, with an average 86.7 particles/kg dry. Fiber particles were the most predominant form (57.1%), followed by films (29.6.2%) and fragments (13.1%). The polymers identified using Fourier Transform Infrared Spectroscopy (FTIR) which was dominantly polyethylene (44.1%), polyethylene terephthalate (35.0%) and nylon (20.2%). It is clear that the microplastics levels in sediment from Euphrates river were polluted and these data will be useful for manage and rehabilitation the Iraqi rivers to reduce possible microplastics pollution.
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| 8. |
- Kanduc, Matej, et al.
(författare)
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Attraction between neutral dielectrics mediated by multivalent ions in an asymmetric ionic fluid
- 2012
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 137:17
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Tidskriftsartikel (refereegranskat)abstract
- We study the interaction between two neutral plane-parallel dielectric bodies in the presence of a highly asymmetric ionic fluid, containing multivalent as well as monovalent (salt) ions. Image charge interactions, due to dielectric discontinuities at the boundaries, as well as effects from ion confinement in the slit region between the surfaces are taken fully into account, leading to image-generated depletion attraction, ion correlation attraction, and steric-like repulsive interactions. We investigate these effects by employing a combination of Monte Carlo simulation methods, including explicit-ion simulations (where all electrostatic interactions are simulated explicitly) and implicit-ion simulations (where monovalent ions are replaced by an effective screened electrostatic potential between multivalent ions), as well as an approximate analytical theory. The latter incorporates strong ion-image charge correlations, which develop in the presence of high valency ions in the mixture. We show that the implicit-ion simulations and the proposed analytical theory can describe the explicit simulation results on a qualitative level, while excellent quantitative agreement can be obtained for sufficiently large monovalent salt concentrations. The resultant attractive interaction between the neutral surfaces is shown to be significant, as compared with the usual van der Waals interactions between semi-infinite dielectrics, and can thus play an important role at the nano scale. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4763472]
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| 9. |
- Kanduc, Matej, et al.
(författare)
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Dressed counterions: Polyvalent and monovalent ions at charged dielectric interfaces
- 2011
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Ingår i: Physical Review E (Statistical, Nonlinear, and Soft Matter Physics). - 1539-3755. ; 84:1
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the ion distribution and overcharging at charged interfaces with dielectric inhomogeneities in the presence of asymmetric electrolytes containing polyvalent and monovalent ions. We formulate an effective "dressed counterion" approach by integrating out the monovalent salt degrees of freedom and show that it agrees with results of explicit Monte Carlo simulations. We then apply the dressed counterion approach within the framework of the generalized strong-coupling theory, valid for polyvalent ions at low concentrations, which enables an analytical description for salt effects as well as dielectric inhomogeneities in the limit of strong Coulomb interactions. Limitations and applicability of this theory are examined by comparing the results with simulations.
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| 10. |
- Kanduc, Matej, et al.
(författare)
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Dressed counterions: Strong electrostatic coupling in the presence of salt
- 2010
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 132:12
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Tidskriftsartikel (refereegranskat)abstract
- We reformulate the theory of strong electrostatic coupling in order to describe an asymmetric electrolyte solution of monovalent salt ions and polyvalent counterions using field-theoretical techniques and Monte Carlo simulations. The theory is based on an asymmetric treatment of the different components of the electrolyte solution. The weak coupling Debye-Huumlckel approach is used in order to describe the monovalent salt ions while a strong coupling approach is used to tackle the polyvalent counterions. This combined weak-strong coupling approach effectively leads to dressed interactions between polyvalent counterions and thus directly affects the correlation attraction mediated by polyvalent counterions between like-charged objects. The general theory is specifically applied to a system composed of two uniformly charged plane-parallel surfaces in the presence of salt and polyvalent counterions. In the strong coupling limit for polyvalent counterions, the comparison with Monte Carlo simulations shows good agreement for large enough values of the electrostatic coupling parameter. We delineate two limiting laws that in fact encompass all the Monte Carlo data.
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