Total Versus Inorganic and Organic Species of As, Cr, and Sb in Flavored and Functional Drinking Waters: Analysis and Risk Assessment.

Packing material can release certain elements such as As, Cr, or Sb into its content and, thus, contaminate the drinking water. The effect of As, Cr, and Sb on human health depends highly on the chemical species in which these elements are introduced into the body. For the above reasons quantification and speciation of As, Cr, and Sb in flavored and functional drinking water samples is an important issue.

Study on Speciation of As, Cr, and Sb in Bottled Flavored Drinking Water Samples Using Advanced Analytical Techniques IEC/SEC-HPLC/ICP-DRC-MS and ESI-MS/MS.

The main aim of the research was to develop a complementary analytical approach consisting of bespoke speciation analysis and non-targeted speciation analysis of As, Sb, and Cr in flavored bottled drinking water samples using HPLC/ICP-DRC-MS and ESI-MS/MS. The scope of two previously developed analytical procedures, (1) multielemental speciation procedure for As, As, Cr, Sb, and Sb analysis and (2) arsenic speciation procedure for AsB, As, DMA, MMA, and As quantification, was extended to the analysis of a new sample type in terms of bespoke speciation analysis. As for the non-targeted speciation, analysis size exclusion chromatography was used with ICP-MS and a complementary technique, ESI-MS/MS, was used for the organic species of As, Sb, and Cr screening.

Which organ should be considered a reference in diffusion weighted imaging of the abdomen?: The reproducibility of ADC measurements of the spleen and the renal cortex on a 1.5T MR.

Background: Diffusion weighted imaging (DWI) is a useful tool for the evaluation of focal lesions in the liver or kidneys, as well as for the diagnosis and assessment of the liver fibrosis process. Some reports show that the spleen and kidneys may serve as reference organs in the staging of liver fibrosis or the evaluation of focal liver lesions.

Objectives: The aim of the study was to determine whether the spleen and renal cortex can be used as reference organs in the DWI technique.

Multielemental analysis of 18 essential and toxic elements in amniotic fluid samples by ICP-MS: Full procedure validation and estimation of measurement uncertainty.

Amniotic fluid is the substantial factor in the development of an embryo and fetus due to the fact that water and solutes contained in it penetrate the fetal membranes in an hydrostatic and osmotic way as well as being swallowed by the fetus. Elemental composition of amniotic fluid influences the growth and health of the fetus, therefore, an analysis of amniotic fluid is important because the results would indicate abnormal levels of minerals or toxic elements. Inductively coupled plasma mass spectroscopy (ICP-MS) is often used for determination of trace and ultra-trace level elements in a wide range of matrices including biological samples because of its unique analytical capabilities.

Polymorphism of 12 STR loci included in the Investigator HD-plex kit in Polish population of Lodz region.

In this study Polish population data as well as efficiency parameters of 12 STR included in the Investigator HDplex set were presented. This set contains 9 systems not available in any other commercial multiplexes, ie.: D2S1360, D3S1744, D4S2366, D5S2500, D6S474, D7S1517, D8S1132, D10S2325 and D21S2055.

Population database on: D1S1656, D2S441, D2S1338, D3S1358, D8S1179, D10S1248, D22S1045, D12S391, D16S539, D18S51, D19S433, D21S11, FGA, TH01, vWA loci included in NGM system based on one thousand unrelated individuals from Lodz region of Central Poland.

A population data obtained on the basis of sample of 1000 unrelated individuals of Polish ancestry living in Lodz region of Central Poland with use of fluorescent multiplex-PCR and capillary electrophoresis were presented. Evaluation included 15 polymorphic loci DNA - STR from NGM multiplex-PCR set, ie. D1S1656, D2S441, D2S1338, D3S1358, D8S1179, D10S1248, D12S391, D16S539, D18S51, D19S433, D21S11, D22S1045, FGA, TH01, vWA.

Infrared and fluorescence assessment of the hydration status of the tryptophan gate in the influenza A M2 proton channel.

The M2 proton channel of the influenza A virus has been the subject of extensive studies because of its critical role in viral replication. As such, we now know a great deal about its mechanism of action, especially how it selects and conducts protons in an asymmetric fashion. The conductance of this channel is tuned to conduct protons at a relatively low biologically useful rate, which allows acidification of the viral interior of a virus entrapped within an endosome, but not so great as to cause toxicity to the infected host cell prior to packaging of the virus.

Shear wave elastography of the spleen: evaluation of spleen stiffness in healthy volunteers.

Purpose: The aim of this study was to assess the mean value of spleen stiffness measured by Shear wave elastography in healthy patients and its dependence on age, sex, and spleen dimensions, and to evaluate the repeatability of this method.

Methods: The final study group included 59 healthy volunteers without any clinical evidence of liver disease, portal hypertension, hematological disorders, and without any pathological ultrasonographic spleen findings. Each patient underwent abdominal ultrasound examination and elastography of the liver and the spleen.

Different antibacterial activity of novel theophylline-based ionic liquids - Growth kinetic and cytotoxicity studies.

The aim of this study was to investigate novel theophylline-based ionic liquids and their cytotoxic effects towards model Gram-positive and Gram-negative bacteria (Bacillus cereus and Escherichia coli, respectively). Growth kinetics, respiratory rates and dehydrogenase activities were studied in the presence of ionic liquids at concentrations ranging from 10 to 1000mg/L. Additionally, the influence of ionic liquids on bacterial cells associated with specific interactions based on the structure of cell wall was evaluated.

Accurate quantification of total chromium and its speciation form Cr(VI) in water by ICP-DRC-IDMS and HPLC/ICP-DRC-IDMS.

Two analytical procedures have been developed for the determination of total chromium (TCr) and its highly toxic species, i.e. Cr(VI) in water samples using the following methods: inductively coupled plasma dynamic reaction cell isotope dilution mass spectrometry (ICP-DRC-IDMS) and high performance liquid chromatography inductively coupled plasma dynamic reaction cell isotope dilution mass spectrometry (HPLC/ICP-DRC-IDMS).

Utility of 5-Cyanotryptophan Fluorescence as a Sensitive Probe of Protein Hydration.

Tryptophan (Trp) fluorescence has been widely used to interrogate the structure, dynamics, and function of proteins. In particular, it provides a convenient and site-specific means to probe a protein's hydration status and dynamics. Herein, we show that a tryptophan analogue, 5-cyanotryptophan (TrpCN), can also be used for this purpose, but with the benefit of enhanced sensitivity to hydration.

C≡N stretching vibration of 5-cyanotryptophan as an infrared probe of protein local environment: what determines its frequency?

Recently it has been suggested that the C≡N stretching vibration of a tryptophan analog, 5-cyanotryptophan, could be used as an infrared probe of the local environment, especially the hydration status, of tryptophan residues in proteins. However, the factors that influence the frequency of this vibrational mode are not understood. To determine these factors, herein we carried out linear and nonlinear infrared measurements on the C≡N stretching vibration of the sidechain of 5-cyanotryptophan, 3-methyl-5-cyanoindole, in a series of protic and aprotic solvents.

A Rare Case of Aggressive Fibromatosis Infiltrating Dorsal Muscles in a 6-Year-Old Patient - CT, MRI and Elastography Evaluation.

Background: The term fibromatosis or desmoid tumor refers to a group of benign fibrous growths without metastatic potential but with a significant risk of local recurrence. These lesions typically present infiltrative growth pattern with local invasion of adjacent tissues. This tendency is the reason for a relatively high rate of local recurrence, even after surgical removal.

Kinetics of peptide folding in lipid membranes.

Despite our extensive understanding of water-soluble protein folding kinetics, much less is known about the folding dynamics and mechanisms of membrane proteins. However, recent studies have shown that for relatively simple systems, such as peptides that form a transmembrane α-helix, helical dimer, or helix-turn-helix, it is possible to assess the kinetics of several important steps, including peptide binding to the membrane from aqueous solution, peptide folding on the membrane surface, helix insertion into the membrane, and helix-helix association inside the membrane. Herein, we provide a brief review of these studies and also suggest new initiation and probing methods that could lead to improved temporal and structural resolution in future experiments.

Tightening up the structure, lighting up the pathway: Application of molecular constraints and light to manipulate protein folding, self-assembly and function.

Chemical cross-linking provides an effective avenue to reduce the conformational entropy of polypeptide chains and hence has become a popular method to induce or force structural formation in peptides and proteins. Recently, other types of molecular constraints, especially photoresponsive linkers and functional groups, have also found increased use in a wide variety of applications. Herein, we provide a concise review of using various forms of molecular strategies to constrain proteins, thereby stabilizing their native states, gaining insight into their folding mechanisms, and/or providing a handle to trigger a conformational process of interest with light.

Chromium and its speciation in water samples by HPLC/ICP-MS--technique establishing metrological traceability: a review since 2000.

Chromium holds a special position among living organisms because depending on its species it can be either essential or toxic. Cr(VI) even at very low concentrations is harmful and carcinogenic, while Cr(III) is a necessary microelement for cellular metabolism. Therefore, a simple analysis of Cr concentration in collected samples will not be able to distinguish these differences effectively: for a proper chemical analysis we need to perform a reliable detection and quantification of Cr species.

How quickly can a β-hairpin fold from its transition state?

Understanding the structural nature of the free energy bottleneck(s) encountered in protein folding is essential to elucidating the underlying dynamics and mechanism. For this reason, several techniques, including Φ-value analysis, have previously been developed to infer the structural characteristics of such high free-energy or transition states. Herein we propose that one (or few) appropriately placed backbone and/or side chain cross-linkers, such as disulfides, could be used to populate a thermodynamically accessible conformational state that mimics the folding transition state.

Aggregation gatekeeper and controlled assembly of Trpzip β-hairpins.

Protein and peptide aggregation is an important issue both in vivo and in vitro. Herein, we examine the aggregation behaviors of two well-studied β-hairpins, Trpzip1 and Trpzip2. Previous studies suggested that Trpzip2 remains monomeric up to a concentration of ~15 mM whereas Trpzip1 readily aggregates at micromolar concentrations at acidic or neutral pH.

Mutagenesis of mitochondrial DNA in Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is an age-related, slowly progressive disease, which may lead to loss of vision resulting from apoptosis of corneal endothelial (CE) cells, dysfunction of Descemet membrane (DM) and corneal edema. A growing body of evidence suggests that oxidative stress may play a major role in the pathogenesis of FECD and that mitochondria of CE cells are its main target. Mitochondrial DNA (mtDNA) is particularly prone to oxidative stress and changes in mtDNA were reported in FECD patients.

Assessment of local friction in protein folding dynamics using a helix cross-linker.

Internal friction arising from local steric hindrance and/or the excluded volume effect plays an important role in controlling not only the dynamics of protein folding but also conformational transitions occurring within the native state potential well. However, experimental assessment of such local friction is difficult because it does not manifest itself as an independent experimental observable. Herein, we demonstrate, using the miniprotein trp-cage as a testbed, that it is possible to selectively increase the local mass density in a protein and hence the magnitude of local friction, thus making its effect directly measurable via folding kinetic studies.

[Evaluation of the impact of symptomatic gastroesophageal reflux disease on the result of surgical treatment with the use of endoscopic techniques and postoperative pharmacological treatment in patients with chronic sinusitis].

It is estimated that in Europe 10% of adults suffer from chronic sinusitis. Chronic sinusitis can be caused by many different diseases that share chronic inflammation of the sinuses as a common symptom. Rhinitis can be caused by stomach acid coming up from the stomach into the esophagus, which successively can result in chronic sinusitis.

Amide I Band and Photoinduced Disassembly of a Peptide Hydrogel.

Peptide hydrogels are promising candidates for a wide range of medical and biotechnological applications. To further expand the potential utility of peptide hydrogels, herein we demonstrate a simple yet effective strategy to render peptide hydrogels photodegradable, making controlled disassembly of the gel structure of interest feasible. In addition, we find that the high-frequency amide I' component (i.

The influence of bacterial biofilm on the clinical outcome of chronic rhinosinusitis: a prospective, double-blind, scanning electron microscopy study.

The aim of this study was to assess the influence of bacterial biofilms in chronic rhinosinusitis (CRS) patients on the clinical outcomes following endoscopic sinus surgery (ESS). This was a prospective, double-blind study. Patients undergoing ESS, because of CRS, were recruited.

DNA damage and repair in Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is a slowly progressive eye disease leading to blindness, mostly affecting people above 40 years old. The only known method of curing FECD is corneal transplantation. The disease is characterized by the presence of extracellular deposits called "cornea guttata", apoptosis of corneal endothelial cells, dysfunction of Descement's membrane and corneal edema.

What is the best DFT functional for vibronic calculations? A comparison of the calculated vibronic structure of the S1-S0 transition of phenylacetylene with cavity ringdown band intensities.

The sensitivity of vibronic calculations to electronic structure methods and basis sets is explored and compared to accurate relative intensities of the vibrational bands of phenylacetylene in the S(1)(A(1)B(2)) ← S(0)(X(1)A(1)) transition. To provide a better measure of vibrational band intensities, the spectrum was recorded by cavity ringdown absorption spectroscopy up to energies of 2000 cm(-1) above the band origin in a slit jet sample. The sample rotational temperature was estimated to be about 30 K, but the vibrational temperature was higher, permitting the assignment of many vibrational hot bands.