scholarly journals Surface water retardation around single-chain polymeric nanoparticles: critical for catalytic function?

2016 ◽  
Vol 7 (3) ◽  
pp. 2011-2015 ◽  
Author(s):  
Patrick J. M. Stals ◽  
Chi-Yuan Cheng ◽  
Lotte van Beek ◽  
Annelies C. Wauters ◽  
Anja R. A. Palmans ◽  
...  
Keyword(s):  
Surface Water ◽  
Functional Groups ◽  
Polymeric Nanoparticles ◽  
Water Soluble ◽  
Single Chain ◽  
Catalytic Function ◽  
Radical Polymerisation

A library of water-soluble dynamic single-chain polymeric nanoparticles (SCPN) was prepared using a controlled radical polymerisation technique followed by the introduction of functional groups, including probes at targeted positions.

Water-Soluble Single-Chain Polymeric Nanoparticles for Highly Selective Cancer Chemotherapy

2020 ◽  
Author(s):  
Chih-Chia Cheng ◽  
Shan-You Huang ◽  
Wen-Lu Fan ◽  
Ai-Wei Lee ◽  
Chih-Wei Chiu ◽  
...  
Keyword(s):  
Cancer Chemotherapy ◽  
Polymeric Nanoparticles ◽  
Water Soluble ◽  
Single Chain

Solubilization of Itraconazole by Surfactants and Phospholipid-Surfactant Mixtures: Interplay of Amphiphile Structure, pH and Electrostatic Interactions

2020 ◽  
Author(s):  
Zahari Vinarov ◽  
Gabriela Gancheva ◽  
Nikola Burdzhiev ◽  
Slavka S. Tcholakova
Keyword(s):  
Nmr Spectroscopy ◽  
Electrostatic Interactions ◽  
Triazole Ring ◽  
Water Soluble ◽  
Single Chain ◽  
Surfactant Mixtures ◽  
Solubilization Capacity ◽  
Water Soluble Drugs ◽  
Hydrophobic Chain ◽  
Brick Dust

Although surfactants are frequently used in enabling formulations of poorly water-soluble drugs, the link between their structure and drug solubilization capacity is still unclear. We studied the solubilization of the “brick-dust” molecule itraconazole by 16 surfactants and 3 phospholipid:surfactant mixtures. NMR spectroscopy was used to study in more details the drug-surfactant interactions. Very high solubility of itraconazole (up to 3.6 g/L) was measured in anionic surfactant micelles at pH = 3, due to electrostatic attraction between the oppositely charged (at this pH) drug and surfactant molecules. <sup>1</sup>H NMR spectroscopy showed that itraconazole is ionized at two sites (2+ charge) at these conditions: in the phenoxy-linked piperazine nitrogen and in the dioxolane-linked triazole ring. The increase of amphiphile hydrophobic chain length had a markedly different effect, depending on the amphiphile type: the solubilization capacity of single-chain surfactants increased, whereas a decrease was observed for double-chained surfactants (phosphatidylglycerols). The excellent correlation between the chain melting temperatures of phosphatidylglycerols and itraconazole solubilization illustrated the importance of hydrophobic chain mobility. This study provides rules for selection of itraconazole solubilizers among classical single-chain surfactants and phospholipids. The basic physics underpinning the described effects suggests that these rules should be transferrable to other “brick-dust” molecules.

scholarly journals How Effective Are Existing Phosphorus Management Strategies in Mitigating Surface Water Quality Problems in the U.S.?

2021 ◽  
Vol 13 (12) ◽  
pp. 6565
Author(s):  
Shama E. Haque
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Management Strategies ◽  
Surface Water Quality ◽  
Land Application ◽  
Water Soluble ◽  
Phosphorus Recovery ◽  
Water Bodies ◽  
The Past ◽  
The U.S

Phosphorus is an essential component of modern agriculture. Long-term land application of phosphorous-enriched fertilizers and animal manure leads to phosphorus accumulation in soil that may become susceptible to mobilization via erosion, surface runoff and subsurface leaching. Globally, highly water-soluble phosphorus fertilizers used in agriculture have contributed to eutrophication and hypoxia in surface waters. This paper provides an overview of the literature relevant to the advances in phosphorous management strategies and surface water quality problems in the U.S. Over the past several decades, significant advances have been made to control phosphorus discharge into surface water bodies of the U.S. However, the current use of phosphorus remains inefficient at various stages of its life cycle, and phosphorus continues to remain a widespread problem in many water bodies, including the Gulf of Mexico and Lake Erie. In particular, the Midwestern Corn Belt region of the U.S. is a hotspot of phosphorous fertilization that has resulted in a net positive soil phosphorous balance. The runoff of phosphorous has resulted in dense blooms of toxic, odor-causing phytoplankton that deteriorate water quality. In the past, considerable attention was focused on improving the water quality of freshwater bodies and estuaries by reducing inputs of phosphorus alone. However, new research suggests that strategies controlling the two main nutrients, phosphorus and nitrogen, are more effective in the management of eutrophication. There is no specific solution to solving phosphorus pollution of water resources; however, sustainable management of phosphorus requires an integrated approach combining at least a reduction in consumption levels, source management, more specific regime-based nutrient criteria, routine soil fertility evaluation and recommendations, transport management, as well as the development of extensive phosphorus recovery and recycling programs.

Human Skin Binding and Absorption of Contaminants from Ground and Surface Water During Swimming and Bathing

1989 ◽  
Vol 8 (5) ◽  
pp. 853-859 ◽  
Author(s):  
Ronald C. Wester ◽  
Howard I. Maibach
Keyword(s):  
Surface Water ◽  
Stratum Corneum ◽  
Human Skin ◽  
The Body ◽  
Water Soluble ◽  
Exposure Effect ◽  
Human Stratum Corneum ◽  
Water Dilution

Contaminants exist in ground and surface water. Human skin has the capacity to bind and then absorb these contaminants into the body during swimming and bathing. Powdered human stratum corneum will bind both lipid-soluble (alachlor, polychlorinated biphenyls [PCBs], benzene) and water-soluble (nitroaniline) chemicals. In vitro (human skin) and in vivo (Rhesus monkey) studies show that these chemicals readily distribute into skin, and then some of the chemical is absorbed into the body. Linearity in binding and absorption exists for nitroaniline over a 10-fold concentration range. Multiple exposure to benzene is at least cumulative. Binding and absorption can be significant for exposures as short as 30 min, and will increase with time. Absorption with water dilution increased for alachlor, but not for dinoseb. Soap reversed the partitioning of alachlor between human stratum corneum and water. The PCBs could be removed from skin by soap and water (70% efficiency) for up to 3 h and then decontamination potential decreased, due to continuing skin absorption. The model in vitro and in vivo systems used should permit easy estimation of this area of extensive human exposure effect on risk assessment.

Staphylococcus aureus: Production of Extracellular Compounds and Behavior in Foods - A Review

1989 ◽  
Vol 52 (4) ◽  
pp. 267-282 ◽  
Author(s):  
MARGARET I. HALPIN-DOHNALEK ◽  
ELMER H. MARTH
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Food Poisoning ◽  
Water Soluble ◽  
Bakery Products ◽  
Single Chain ◽  
Poultry Products ◽  
Heat Stable ◽  
And Behavior ◽  
Red Meats

Growth of Staphylococcus aureus is accompanied by production of such extracellular compounds as hemolysins, nuclease, coagulase, lipase, and enterotoxins. Enterotoxins that can cause food poisoning are produced by about one-third of the coagulase-positive strains of S. aureus. The enterotoxins are a heterogeneous group of heat-stable, water-soluble, single-chain globular proteins having a molecular weight between 28,000 and 35,000 daltons. Production of enterotoxin by appropriate strains of S. aureus is affected by the nutritional quality and pH of the substrate, temperature, atmosphere, sodium chloride (and hence water activity), other chemicals, and competing microorganisms. Outbreaks of staphylococcal food poisoning most often are associated with processed red meats, poultry products (especially chicken salad), sauces, dairy products (especially cheeses), and custard- or cream-filled bakery products. Ham and associated products often are involved in as many as 30% of outbreaks of staphylococcal food poisoning. Most outbreaks result from the combined effects of contamination of the food, often through unsanitary handling, with S. aureus and holding the food at the wrong temperature thus allowing growth and synthesis of enterotoxin by the pathogen.

Water Balance in Giraffes

2021 ◽  
pp. 241-260
Author(s):  
Graham Mitchell
Keyword(s):  
Surface Water ◽  
Urine Volume ◽  
Water Soluble ◽  
Sweat Glands ◽  
Arid Environments ◽  
Water Metabolism ◽  
Access To Water ◽  
Fecal Water ◽  
Kidney Anatomy ◽  
And Function

Wild giraffes live in arid environments. Having access to water and minimizing water requirements are critical. The main sources of water are the water in browse and water generated by metabolism. Giraffes rely less on surface water: intermittent use of surface water is a legendary characteristic of giraffes. The volume of water needed depends on body mass. For a giraffe weighing 750 kg, ~25 L of water is needed daily. The water content of browse is ~60%, and as a giraffe of that mass will eat ~35 kg of fresh browse daily, it simultaneously will acquire ~20 L of water. Metabolism of the fat, carbohydrates, and proteins in 35 kg of fresh browse will produce ~10 L of water. These two sources of water exceed daily requirements and reduce the need to drink surface water. Water is lost through feces, evaporation from the skin and respiratory tract, and in urine. Fecal water loss and water lost in exhaled air amount to ~4 L daily (~2 L each). It is not known if giraffes sweat, but their skin contains active sweat glands. The volume of water lost as sweat will vary according to what thermoregulatory mechanisms are activated to minimize sweating, but may be 5 L daily. Obligatory excretion of water-soluble wastes in urine can account for most water lost daily, and that amount is related to kidney anatomy and function. In a 750-kg giraffe, obligatory urine volume is ~10 L daily.

scholarly journals Properties, processes and regimes of soil solutions and surface waters

2020 ◽  
Vol 175 ◽  
pp. 12022
Author(s):  
Guriyat Podvolotskaya ◽  
Sergey Belopukhov ◽  
Vitaly Savich ◽  
Andrey Sorokin ◽  
Nikolay Tyutrin
Keyword(s):  
Biological Activity ◽  
Surface Water ◽  
Surface Waters ◽  
Pair Correlation ◽  
Rate Of Change ◽  
Water Soluble ◽  
Soil Solutions ◽  
Different Depths ◽  
Different Soils

Soil solutions and the surface waters are characterized by properties, processes and regimes. Soil solutions of different soils and their surface water have different biological activity and change the activity of dissolved stimulants and inhibitors. The object of the study are soil solutions of the main types of soils obtained in the model experiments with the ratio of soils: water equal to 1:1 and 1: 2, soil solutions and surface water in the flooding of soils with water for 1 week – 3 months. The research method consisted in the assessment of pH, Eh, activity of K, NO3, NH4, Ca, Mg by conventional methods, assessment of concentrations of water-soluble compounds extracted from soils by ionite membranes, in the assessment of biological activity of solutions using biotests. The following is suggested for additional evaluation: the using of cation and anion membranes, determination of interrelation between the properties of waters, equation of pair correlation and multiply regression. The informative value of the gradient of surface water concentrations at different distances from the floor of the reservoir, at different depths of the overwatered soils is shown. The mobility of Ca, Mg, Fe, Mn in soils and the content of their water-soluble forms depends on both pH and Eh, whose influence on the content of water-soluble forms of the considered cations shows the effects of synergy and antagonism. The rate of change in the composition of soil solutions during soil flooding depends on a combination of soil properties, temperature, and duration of flooding. Soil solutions of different soils and their surface waters have differentrates.

Water-Soluble, pH Responsive Polymeric Nanoparticles: A Modular Approach

2020 ◽  
Vol 2 (7) ◽  
pp. 2499-2503
Author(s):  
Marcel Klein-Hitpaß ◽  
Jan-Erik Ostwaldt ◽  
Carsten Schmuck ◽  
Michael Giese
Keyword(s):  
Polymeric Nanoparticles ◽  
Water Soluble ◽  
Modular Approach ◽  
Ph Responsive
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