Inorganic soil solution constituents can alter the charge, size, and conformation of dissolved organic molecules, thus affecting their environmental behavior. Here, we investigated how pH, cation ...valence and activities induce conformational changes and aggregation-sedimentation reactions of organic polyelectrolytes. For that we determined the hydrodynamic diameter of the model compound tannic acid by laser light scattering at concentrations of 1–30 g L−1 in the pH range from 3 to 10 and with electrolyte additions of CaCl2 and hydroxyl-Al cations. Charge properties were quantified by polyelectrolyte titration and zeta potential measurements. After dispersion by sonication, aggregation was determined in time sequences up to 60 min and suspension stability was traced in sedimentation experiments. Tannic acid was present in ultrapure water in a self-aggregated state. At pH <3 as well as >7.5, its hydrodynamic diameter increased. Whereas at high pH this behavior could be assigned to unfolding of molecular conformations, at low pH it is likely that charge neutralization decreased repulsive forces and facilitated aggregation. At pH 5 and ionic strengths of up to 5 mM, CaCl2 did not affect aggregation state of tannic acid and results resembled those obtained in ultrapure water. Addition of hydroxyl-Al cations broke-up the self-aggregated tannic acid structures under formation of Al-organic coprecipitates. Strong aggregation only occurred at mixing ratios where opposite surface charges were completely balanced. Under natural conditions, self-aggregation of tannic acid can be expected only at higher solution concentrations. However, at acidic pH, hydroxyl-Al cations and tannic acid may form discrete colloidal particles already at low tannic acid concentrations, resulting in the destabilization of suspensions. Our data emphasize that the soil solution composition strongly modifies the physical state of tannic acid, and likely also of other biopolymers, and thus their interactions within environmental matrices.
Display omitted
•Soil solution composition strongly modifies the physical state of tannic acid.•At low as well as high pH hydrodynamic diameter of tannic acid increased.•Hydroxyl-Al cations broke-up the self-aggregated tannic acid structures.•Strong aggregation occurred at mixing ratios where opposite charges were balanced.•Conformational changes of biopolymers can affect interactions within environmental matrices.
Objectives: N-nitroso compounds, endogenously formed from nitrate-derived nitrite, are suspected to be important bladder carcinogens. However, the association between nitrate exposure from food or ...drinking water and bladder cancer has not been substantially investigated in epidemiologic studies. Methods: We evaluated the associations between nitrate exposure and bladder cancer in the Netherlands Cohort Study, conducted among 120,852 men and women, 55-69 years of age at entry. Information on nitrate from diet was collected via a food frequency questionnaire in 1986 and a database on nitrate content of foods. Individual nitrate exposures from beverages prepared with tap water were calculated by linking the postal code of individual residence at baseline to water company data. After 9.3 years of follow-up and after excluding subjects with incomplete or inconsistent dietary data, 889 cases and 4,441 subcohort members were available for multivariate analyses. We calculated incidence rate ratios (RR) and corresponding 95% confidence intervals (CIs) using Cox regression analyses. We also evaluated possible effect modification of dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever). Results: The multivariate RRs for nitrate exposure from food, drinking water, and estimated total nitrate exposure were 1.06 (95% CI, 0.81-1.31), 1.06 (95% CI, 0.82-1.37), and 1.09 (95% CI, 0.84-1.42), respectively, comparing the highest to the lowest quintiles of intake. Dietary intake of vitamins C and E (low/high) and cigarette smoking (never/ever) had no significant impact on these results. Conclusion: Although the association between nitrate exposure and bladder cancer risk is biologically plausible, our results in this study do not support an association between nitrate exposure and bladder cancer risk.
Turkish vernacular housing architecture is in danger of extinction. Original village patterns deteriorate due to new developments, which are discordant with existing settlements and social lifestyle. ...This paper claims to ensure the cultural continuity of Turkish vernacular housing architecture by adapting new residential designs to the existent environment with a parametric shape grammar method. Originally, vernacular house plans included the allocation of space around a hall: a Sofa. This study firstly exposes spatial organization and grammar rule sets according to the relation between the sofa and remaining spaces, secondly considers current physical problems and villagers’ contemporary living demands and finally creates design solutions coherent with the actual vernacular character by adapting a new design grammar to the existing design.
The Level 1 decision and data flow control subsystems of the CLEO-III trigger produce and distribute a trigger decision every 42 ns based on input from calorimetry and tracking subsystems. This paper ...describes the free-running pipelined trigger decision logic that correlates axial and stereo tracking information, and combines time-aligned calorimetry information onto a common backplane. Programmable trigger decision boards monitor this backplane and can be configured as desired to respond to a wide variety of trigger conditions. The resulting trigger decision is regulated by a throttling mechanism that allows the data-acquisition system to modulate the trigger rate to maximize throughput without buffer overrun. A central signal distribution mechanism delivers the trigger decision and system clock to the front-end electronics.
Abstract Introduction and Aim This study examined the extracorporeal methods for the elimination of toxic substances in poisoned patients that are used by clinicians taking care of such patients. ...Here we present our experience in the use of therapeutic plasma exchange (TPE). To the best of our knowledge, this is the largest number of poisoning cases ever reported in a study. Patients and Methods This is a retrospective study conducted at the Çukurova University Faculty of Medicine, Department of Emergency Medicine, with the permission of the ethical committee of the medical faculty. The study includes patients who had undergone TPE because of poisoning between January 2007 and May 2015. We summarize the clinical data and outcomes of the patients with available files. Results A total of 36 cases among the 42 patients who underwent TPE in this 8-year period were included in the study. More than 20 identified toxic substances, most of which were pesticides, were found to be the causes of poisoning. Twenty-three healthy discharges and 12 deaths are discussed in the study. Conclusion We believe that our study reports the largest ever number of poisoning cases treated with TPE in the literature. When applicable, TPE may be a promising extracorporeal elimination and treatment technique in poisoned patients when performed in selected cases.
Several bilateral internal thoracic artery (ITA) grafting patterns have been proposed to enhance 3-vessel coronary artery revascularization. We present the outcomes of sequential in situ left ITA ...grafting to the circumflex and right coronary artery (RCA) areas.
Between January 2001 and September 2007, 102 patients with 3-vessel coronary artery disease underwent arterial myocardial revascularization with bilateral in situ ITA grafts. The circumflex and distal RCA branches were revascularized sequentially with the left ITA. The left anterior descending artery area was grafted with the right ITA.
Ninety-nine patients (97.0%) were monitored for 37.2 ± 2.9 months, and 77 (75.4%) underwent postoperative coronary imaging after 27.8 ± 5.8 months. The bilateral ITA grafts were 97.1% patent (FitzGibbon grade A+B) overall. The sequential anastomoses of the left ITA to the circumflex and RCA territories were 96.7% patent overall, with competitive flow (FitzGibbon grade B) in 3 patients. The patency rates of sequential anastomoses to the circumflex and RCA branches were 98.0% and 95.0%, respectively. The right posterolateral and right descending posterior artery anastomoses were 91.8% and 100% patent, respectively. The in situ right ITA grafts to the left anterior descending artery area were 98.0% (FitzGibbon grade A+B) patent overall. Angina recurred in 1 patient (0.9%) 6 months after the operation. Percutaneous coronary interventions were performed in 3 patients (3.8%). No cardiac deaths occurred during the follow-up period.
Sequential in situ left ITA grafting to the circumflex and RCA areas yields acceptable midterm results in selected patients with 3-vessel disease.
The tracking subsystem of the CLEO-III Trigger consists of separate axial and stereo tracking pattern-matching modules, whose products are time-aligned and spatially correlated to provide pipelined ...trigger information every 42 ns with a latency of approximately 2 /spl mu/s. This paper describes the pipelined signal processing and pattern recognition schemes used by the axial and stereo electronics to provide the information necessary to make trigger decisions. Extensive use of in-system field programmable gate arrays support path finding and timing information extraction.
PDF
