A research note: Effect of Hofmeister salts on meat iridescence in cooked pork.

The effect of Hofmeister salts (NaCl, NaSCN, Na2SO4, KCl, LiCl, CaCl2) on surface iridescence in cooked pork was investigated. Strongest iridescence occurred in samples treated with NaSCN, NaCl and KCl. Control samples and LiCl, CaCl2 and Na2SO4 treatments showed weaker iridescence. However, differences between KCl and LiCl, CaCl2 and Na2SO4 were not statistically significant (p > 0.05). Nevertheless, a tendency of chaotropic salts (NaSCN, NaCl, KCl) to cause stronger iridescence was noted that might be explained with a more effective solubilization of myofibrillar proteins (MPs), reducing incoherent scattering from the myofibrils and thus enhancing multilayer interference.

Electronic skin based on cellulose/KCl/sorbitol organohydrogel.

With the increasing interests in the fields of wearable devices, it is essential yet also challenging to develop electronic skin with customized functionalities, especially for harsh conditions. Herein, by using KCl as both anti-solvent for cellulose regeneration and ionic charge carrier in the cellulose gel network, cellulose/KCl/sorbitol organohydrogel (CKS) combining transparency (over 95% at 550 nm), stretchability (235%), high conductivity (3.88 S/m), and low temperature tolerance (-51.8 °C) was prepared. The CKS based electronic skin achieved simultaneous monitoring of object contact-separation/pressure, stretching/bending and thermal variation, with excellent reliability and stability even in harsh conditions, resembling the human skin with multiply functions. The CKS based electronic skin as efficient human-machine interface was also demonstrated. Furthermore, the CKS based triboelectric nanogenerator delivered a power density of 991 mW/m2, potential as mechanical energy harvesters for wearable devices. We believe the present work will inspire the development of cellulose based skin-like materials and contribute to the comprehensive utilization of naturel polymer in the field of smart devices.

The Influences of Sulphation, Salt Type, and Salt Concentration on the Structural Heterogeneity of Glycosaminoglycans.

The increasing recognition of the biochemical importance of glycosaminoglycans (GAGs) has in recent times made them the center of attention of recent research investigations. It became evident that subtle conformational factors play an important role in determining the relationship between the chemical composition of GAGs and their activity. Therefore, a thorough understanding of their structural flexibility is needed, which is addressed in this work by means of all-atom molecular dynamics (MD) simulations. Four major GAGs with different substitution patterns, namely hyaluronic acid as unsulphated GAG, heparan-6-sulphate, chondroitin-4-sulphate, and chondroitin-6-sulphate, were investigated to elucidate the influence of sulphation on the dynamical features of GAGs. Moreover, the effects of increasing NaCl and KCl concentrations were studied as well. Different structural parameters were determined from the MD simulations, in combination with a presentation of the free energy landscape of the GAG conformations, which allowed us to unravel the conformational fingerprints unique to each GAG. The largest effects on the GAG structures were found for sulphation at position 6, as well as binding of the metal ions in the absence of chloride ions to the carboxylate and sulphate groups, which both increase the GAG conformational flexibility.

Cation enrichment in the ion atmosphere is promoted by local hydration of DNA.

Electrostatic interactions are central to the structure and function of nucleic acids, including their folding, condensation, and interaction with proteins and other charged molecules. These interactions are profoundly affected by ions surrounding nucleic acids, the constituents of the so-called ion atmosphere. Here, we report precise Fourier Transform-Terahertz/Far-Infrared (FT-THz/FIR) measurements in the frequency range 30-500 cm-1 for a 24-bp DNA solvated in a series of alkali halide (NaCl, NaF, KCl, CsCl, and CsF) electrolyte solutions which are sensitive to changes in the ion atmosphere. Cation excess in the ion atmosphere is detected experimentally by observation of cation modes of Na+, K+, and Cs+ in the frequency range between 70-90 cm-1. Based on MD simulations, we propose that the magnitude of cation excess (which is salt specific) depends on the ability of the electrolyte to perturb the water network at the DNA interface: In the NaF atmosphere, the ions reduce the strength of interactions between water and the DNA more than in case of a NaCl electrolyte. Here, we explicitly take into account the solvent contribution to the chemical potential in the ion atmosphere: A decrease in the number of bound water molecules in the hydration layer of DNA is correlated with enhanced density fluctuations, which decrease the free energy cost of ion-hydration, thus promoting further ion accumulation within the DNA atmosphere. We propose that taking into account the local solvation is crucial for understanding the ion atmosphere.

Influence of KCl Fertilizer and Trichoderma on the Growth and Yield of Upland Rice.

<b>Background and Objective:</b> The rate of population growth is not balanced with the rate of increase in national rice production. The attention of the government and researchers in Southeast Sulawesi on upland rice is still very low, even though the potential for increased upland rice production is quite promising. The research aimed to study the influence of KCl fertilizer and <i>Trichoderma </i>spp. on the growth and yield of upland rice. <b>Materials and Methods:</b> The study was conducted in a Randomized Block Design (RBD) consisting of 6 treatments i.e.: without KCl fertilizer and <i>T. asperellum</i> (K₀), KCl 0.15 g/polybag+<i>T. asperellum </i>50 g/polybag (K₁), KCl 0.30 g/polybag+<i> T. asperellum </i>40 g/polybag (K₂), KCl 0.45 g/polybag+<i>T. asperellum </i>30 g/polybag (K₃), KCl 0.60 g/polybag+<i>T. asperellum </i>20 g/polybag (K₄) and KCl 0.75 g/polybag+<i>T. asperellum </i>10 g/polybag (K₅) with 4 replication for each treatment. The data obtained were analyzed by analysis of variance (ANOVA) and conducted further tests with the Duncan Multiple Range Test (DMRT) at a 95% confidence level. <b>Results:</b> The results of the research revealed KCl fertilizer combination with <i>T. asperellum</i> in general, can increase the growth and yield of upland local aromatic red rice. Application of KCl fertilizers as 0.45 g/polybag equivalent to 90 kg ha¹ (K₃) can provide optimal potassium nutrients for vegetative growth of upland rice. <b>Conclusion:</b> The treatment of KCl fertilizer as 0.45 g/polybag with <i>T. asperellum </i>30 g/polybag (K₃) provides growth and yield of upland rice with an average production of4.95 t ha¹.

3D Bioprinting Mesenchymal Stem Cell-Derived Neural Tissues Using a Fibrin-Based Bioink.

Current treatments for neurodegenerative diseases aim to alleviate the symptoms experienced by patients; however, these treatments do not cure the disease nor prevent further degeneration. Improvements in current disease-modeling and drug-development practices could accelerate effective treatments for neurological diseases. To that end, 3D bioprinting has gained significant attention for engineering tissues in a rapid and reproducible fashion. Additionally, using patient-derived stem cells, which can be reprogrammed to neural-like cells, could generate personalized neural tissues. Here, adipose tissue-derived mesenchymal stem cells (MSCs) were bioprinted using a fibrin-based bioink and the microfluidic RX1 bioprinter. These tissues were cultured for 12 days in the presence of SB431542 (SB), LDN-193189 (LDN), purmorphamine (puro), fibroblast growth factor 8 (FGF8), fibroblast growth factor-basic (bFGF), and brain-derived neurotrophic factor (BDNF) to induce differentiation to dopaminergic neurons (DN). The constructs were analyzed for expression of neural markers, dopamine release, and electrophysiological activity. The cells expressed DN-specific and early neuronal markers (tyrosine hydroxylase (TH) and class III beta-tubulin (TUJ1), respectively) after 12 days of differentiation. Additionally, the tissues exhibited immature electrical signaling after treatment with potassium chloride (KCl). Overall, this work shows the potential of bioprinting engineered neural tissues from patient-derived MSCs, which could serve as an important tool for personalized disease models and drug-screening.

A simple and rapid HPLC method for determination of parabens and their degradation products in pharmaceutical dosage forms.

A stability-indicating HPLC method was developed for the simultaneous determination of paraben mixture and its degradation products in effervescent potassium chloride tablets. The chromatographic separation was achieved on a Waters Cortecs C18 column (2.7 µm, 4.6 × 150 mm) using gradient elution. The optimized mobile phase consisted of 0.1% orthophosphoric acid in purified water as solvent A and purified water, acetonitrile, and orthophosphoric acid (100:900:1, v/v) as solvent B. The flow rate was 0.8 mL/min, and column temperature was maintained at 35°C. The injection volume was 10 µL, and UV detection was carried out at 254 nm. The selectively developed method has optimal separation among p-hydroxybenzoic acid, methylparaben, ethylparaben, propylparaben, and butylparaben peaks in the presence of specified and unspecified degradation products in the determination of drug product. The mass balance obtained from forced degradation studies was ≥95% and thus proves the stability-indicating property of the developed method. The developed reversed-phase HPLC method has been validated according to the International Conference on Harmonization guidelines. The correlation coefficients for all the peaks were >0.9999. The results of the other validation parameters were found within the limits. Finally, the optimized method was used in the quality control lab for stability analysis.

Strategies to reduce sodium levels in European seabass sausages.

Considering the increasing demand towards "ready-to-cook" processed seafood products, recognised as being potential contributors to high sodium (Na) intake by consumers, this study aimed to assess the effect of sodium chloride (NaCl) reduction on physicochemical, microbiological and sensory properties of European seabass (Dicentrarchus labrax) sausages stored in chilling conditions during 5 weeks. Three formulations were tested in comparison with a control (100% NaCl, CTR): (i) 50% NaCl+50% ME (oleoresins microcapsules) (F1); (ii) 50% NaCl+50% KCl (F2); and (iii) only 50% NaCl (F3). The NaCl reduction mainly affected the texture and the salty taste, resulting in softer and perceived as less salty sausages after processing. However, hardness differences disappeared after 5 weeks. It seems that an antioxidant protection was obtained in sausages formulated with oleoresins microcapsules. No or low growth of psychrotrophic and mesophilic bacteria was observed (≤2.40 log CFU/g). Decreasing NaCl content and/or partially replacing it (50%) by KCl or oleoresins microcapsules seem to be suitable solutions to reduce Na (30.9-36.3%) levels, while maintaining the chilled sausages quality for 5 weeks. The partial replacement of NaCl by KCl also allows obtaining a product richer in K (997.2 mg/100 g), which ingestion may contribute for a cardiovascular protective effect.

Miniaturized probe on polymer SU-8 with array of individually addressable microelectrodes for electrochemical analysis in neural and other biological tissues.

An SU-8 probe with an array of nine, individually addressable gold microband electrodes (100 µm long, 4 µm wide, separated by 4-µm gaps) was photolithographically fabricated and characterized for detection of low concentrations of chemicals in confined spaces and in vivo studies of biological tissues. The probe's shank (6 mm long, 100 µm wide, 100 µm thick) is flexible, but exhibits sufficient sharpness and rigidity to be inserted into soft tissue. Laser micromachining was used to define probe geometry by spatially revealing the underlying sacrificial aluminum layer, which was then etched to free the probes from a silicon wafer. Perfusion with fluorescent nanobeads showed that, like a carbon fiber electrode, the probe produced no noticeable damage when inserted into rat brain, in contrast to damage from an inserted microdialysis probe. The individual addressability of the electrodes allows single and multiple electrode activation. Redox cycling is possible, where adjacent electrodes serve as generators (that oxidize or reduce molecules) and collectors (that do the opposite) to amplify signals of small concentrations without background subtraction. Information about electrochemical mechanisms and kinetics may also be obtained. Detection limits for potassium ferricyanide in potassium chloride electrolyte of 2.19, 1.25, and 2.08 µM and for dopamine in artificial cerebral spinal fluid of 1.94, 1.08, and 5.66 µM for generators alone and for generators and collectors during redox cycling, respectively, were obtained.

Effect of processing smoked salmon on contaminant contents.

The influence of the type of smoking process (natural/liquid; hot/cold) and salt (NaCl or KCl) on the levels of polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) in smoked salmon was evaluated. One parent compound - BDE 47 - and two methoxylated forms - 2'-MeO-BDE-68 and 6-MeO-BDE-47 - were detected in all the samples. Among the 14 PAHs analysed, naphthalene was the most abundant followed by phenanthrene and fluorene. Only smoked salmon treated with NaCl presented quantifiable levels of chrysene and benzo[b]fluoranthene. Among the four smoking processes evaluated, natural smoke led to higher levels of PAHs. Risk characterization tools, such as hazard index (HI) and incremental lifetime cancer risk (ILCR), showed that the risk of both PBDEs and PAHs to human health through the consumption of smoked salmon was very low.

Study of the Pathogen Inactivation Mechanism in Salt-Coated Filters.

As COVID-19 exemplifies, respiratory diseases transmitted through aerosols or droplets are global threats to public health, and respiratory protection measures are essential first lines of infection prevention and control. However, common face masks are single use and can cause cross-infection due to the accumulated infectious pathogens. We developed salt-based formulations to coat membrane fibers to fabricate antimicrobial filters. Here, we report a mechanistic study on salt-induced pathogen inactivation. The salt recrystallization following aerosol exposure was characterized over time on sodium chloride (NaCl), potassium sulfate (K2SO4), and potassium chloride (KCl) powders and coatings, which revealed that NaCl and KCl start to recrystallize within 5 min and K2SO4 within 15 min. The inactivation kinetics observed for the H1N1 influenza virus and Klebsiella pneumoniae matched the salt recrystallization well, which was identified as the main destabilizing mechanism. Additionally, the salt-coated filters were prepared with different methods (with and without a vacuum process), which led to salt coatings with different morphologies for diverse applications. Finally, the salt-coated filters caused a loss of pathogen viability independent of transmission mode (aerosols or droplets), against both DI water and artificial saliva suspensions. Overall, these findings increase our understanding of the salt-recrystallization-based technology to develop highly versatile antimicrobial filters.

Thermodiffusion of aqueous solutions of various potassium salts.

Thermophoresis or thermodiffusion has become an important tool to monitor protein-ligand binding as it is very sensitive to the nature of solute-water interactions. However, the microscopic mechanisms underlying thermodiffusion in protein systems are poorly understood at this time. One reason is the difficulty to separate the effects of the protein system of interest from the effects of buffers that are added to stabilize the proteins. Due to the buffers, typical protein solutions form multicomponent mixtures with several kinds of salt. To achieve a more fundamental understanding of thermodiffusion of proteins, it is therefore necessary to investigate solutions of buffer salts. For this work, the thermodiffusion of aqueous potassium salt solutions has been studied systematically. We use thermal diffusion forced Rayleigh scattering experiments in a temperature range from 15 °C to 45 °C to investigate the thermodiffusive properties of aqueous solutions of five potassium salts: potassium chloride, potassium bromide, potassium thiocyanate, potassium acetate, and potassium carbonate in a molality range between 1 mol/kg and 5 mol/kg. We compare the thermophoretic results with those obtained for non-ionic solutes and discuss the thermophoresis of the salts in the context of ion-specific solvation according to the Hofmeister series.

Evaluation of small molecular metabolites and sensory properties of Xuanwei ham salted with partial replacement of NaCl by KCl.

The study was to understand the effect of the partial substitution of NaCl by KCl on small molecular metabolites and sensory quality of Xuanwei ham. Thirty green hams were randomly divided into five treatments, and salted with 100% NaCl (I), 70% NaCl+30% KCl (II), 60% NaCl+40% KCl (III), 50% NaCl+50% KCl (IV) and 40% NaCl+60% KCl (V), respectively. With the increase of KCl substitution, the moisture content of Xuanwei ham increased. Non-targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-Q-Exactive-MS) was used to study the effect of partial substitution of NaCl by KCl, and twenty-eight metabolites were identified as markers of small molecular metabolites in the different treatments. KCl substitution promoted the release of tryptophan, histidine, citrulline, lysine, creatine and oleic acid, which contributed to improve the flavor and taste of ham. Therefore, the treatment II and III could reduce the NaCl content of Xuanwei ham by 30% and 40%, and maintained a better sensory acceptability.

Viscoelasticity of biomolecular condensates conforms to the Jeffreys model.

Biomolecular condensates, largely by virtue of their material properties, are revolutionizing biology, and yet, the physical understanding of these properties is lagging. Here, I show that the viscoelasticity of condensates can be captured by a simple model, comprising a component where shear relaxation is an exponential function (with time constant τ1) and a component with nearly instantaneous shear relaxation (time constant τ0 → 0). Modulation of intermolecular interactions, e.g., by adding salt, can disparately affect the two components such that the τ1 component may dominate at low salt, whereas the τ0 component may dominate at high salt. Condensates have a tendency to fuse, with the dynamics accelerated by interfacial tension and impeded by viscosity. For fast-fusion condensates, shear relaxation on the τ1 timescale may become rate-limiting such that the fusion speed is no longer in direction proportion to the interfacial tension. These insights help narrow the gap in understanding between the biology and physics of biomolecular condensates.

Characterisation of the flavour profile of dry fermented sausages with different NaCl substitutes using HS-SPME-GC-MS combined with electronic nose and electronic tongue.

The effects of different sodium substitutes on the physical and bacterial properties, flavour profile and sensory evaluation of dry fermented sausage were investigated. There were three different salt formulations, including control (C: 100%NaCl), S1 (70%NaCl and 30%KCl) and S2 (70%NaCl, 20%KCl and 10% flavour enhancers). Higher moisture content and lactic acid bacteria count, and lower pH and Staphylococcus count were observed in NaCl substitution treatments compared to the control (P < 0.05). Sixty-two volatiles were detected in sausages, and 26 compounds were regarded as key volatile compounds based on the odour activity values. The electronic tongue result and sensory evaluation showed that the taste profile of S2 treatment was similar to control treatment; and the electronic nose, volatile compound results and hierarchical cluster analysis showed that the sodium substitutes had a more significant effect on the odour profile. Overall, S2 may be an ideal low-sodium substitute to achieve a 30% reduction in NaCl and provide a better flavour profile of fermented sausages.

[Injectable concentrated potassium concentrate, emblematic of the lack of safety of the drug use process in French hospitals]. / Le potassium injectable concentré, emblématique de l'insécurité médicamenteuse des hôpitaux français.

Despite its proven dangers, the ward stock drug distribution system predominates in French hospitals. This system allows 12 million injectable ampoules of concentrated potassium chloride to circulate uncontrolled each year. Such a situation is absurd for the following reasons : 1) injected by mistake, concentrated potassium kills within seconds ; 2) the true incidence of potassium-related fatalities and incidents is unknown ; 3) fatal intravenous injection of potassium produces no specific anatomical changes and subtle, if any, findings at autopsy ; 4) it is used for capital punishment by lethal injection in various countries ; and 5) healthcare worker serial killers benefit from the fact that potassium is not identifiable in post-mortem examinations and that investigations to find the murderer are complex and of uncertain outcome. Other medications classed as high-risk have similar characteristics to those of concentrated potassium solutions. Injectable potassium can therefore be regarded as emblematic of the lack of safety of the drug use process in French hospitals. The priority measure to protect patients from this deadly risk is to remove these drugs from uncontrolled ward stocks and to provide premixed potassium solutions. Evidence of the increased safety of the unit dose drug dispensing system should compel health policy makers to systematically implement it, thus bringing the drug use process into compliance with existing French and European regulations.

HTK-N: Modified Histidine-Tryptophan-Ketoglutarate Solution-A Promising New Tool in Solid Organ Preservation.

To ameliorate ischemia-induced graft injury, optimal organ preservation remains a critical hallmark event in solid organ transplantation. Although numerous preservation solutions are in use, they still have functional limitations. Here, we present a concise review of a modified Histidine-Tryptophan-Ketoglutarate (HTK) solution, named HTK-N. Its composition differs from standard HTK solution, carrying larger antioxidative capacity and providing inherent toxicity as well as improved tolerance to cold aiming to attenuate cold storage injury in organ transplantation. The amino acids glycine, alanine and arginine were supplemented, N-acetyl-histidine partially replaced histidine, and aspartate and lactobionate substituted chloride. Several in vitro studies confirmed the superiority of HTK-N in comparison to HTK, being tested in vivo in animal models for liver, kidney, pancreas, small bowel, heart and lung transplantation to adjust ingredients for required conditions, as well as to determine its innocuousness, applicability and potential advantages. HTK-N solution has proven to be advantageous especially in the preservation of liver and heart grafts in vivo and in vitro. Thus, ongoing clinical trials and further studies in large animal models and consequently in humans are inevitable to show its ability minimizing ischemia-induced graft injury in the sequel of organ transplantation.

Single-molecule level dynamic observation of disassembly of the apo-ferritin cage in solution.

The ferritin cage iron-storage protein assembly has been widely used as a template for preparing nanomaterials. This assembly has a unique pH-induced disassembly/reassembly mechanism that provides a means for encapsulating molecules such as nanoparticles and small enzymes for catalytic and biomaterial applications. Although several researchers have investigated the disassembly process of ferritin, the dynamics involved in the initiation of the process and its intermediate states have not been elucidated due to a lack of suitable methodology to track the process in real-time. We describe the use of high-speed atomic force microscopy (HS-AFM) to image the dynamic event in real-time with single-molecule level resolution. The HS-AFM movies produced in the present work enable direct visualization of the movements of single ferritin cages in solution and formation of a hole prior to disassembly into subunit fragments. Additional support for these observations was confirmed at the atomic level by the results of all-atom molecular dynamics (MD) simulations, which revealed that the initiation process includes the opening of 3-fold symmetric channels. Our findings provide an essential contribution to a fundamental understanding of the dynamics of protein assembly and disassembly, as well as efforts to redesign the apo-ferritin cage for extended applications.

Effect of the sodium reduction and smoking system on quality and safety of smoked salmon (Salmo salar).

Excessive sodium (Na) intake has been associated with high blood pressure and cardiovascular diseases. Therefore, sodium reduction is a public health challenge worldwide. The aim of this study was to develop smoked salmon with a reduced Na content. Sodium chloride (NaCl) was replaced by potassium chloride (KCl) at 25% and 50% (molar replacement) and studied in combination with two smoking procedures (natural wood and liquid smoke) as well as two smoking temperatures (18-19 °C or 56 °C). Smoked salmon samples were characterized by physicochemical, sensory and microbiological analyses. No major differences were observed regarding physicochemical properties in the studied treatments. Smoked samples with 50% of NaCl replaced by KCl were slightly more bitter than those with 25% whereas samples with 25% of replacement did not show differences to those with non-reduced Na content (5 g of added NaCl per 100 g of salmon). Molar Na:K ratio decreased from 4,3 in controls to 1,4 and 0,6 in samples with a NaCl reduction level of 25% and 50% respectively. Microbiological assessment indicates that 2-week shelf-life would be appropriate and safe in terms of accomplishment of the EU regulation, taking into account foreseeable storage temperatures (up to 8 °C). Thus, it is possible to achieve a reduction of 25-50% of NaCl in smoked salmon by replacing NaCl by KCl and considerer this product as a "source" of K.

Study on the mechanism of KCl replacement of NaCl on the water retention of salted pork.

The reasons for the change in the water retention capability of salted pork caused by potassium chloride (KCl) instead of sodium chloride (NaCl) were investigated. Accompanied by the gradually increased substitution rate of KCl, the oxidative degradation of protein, water content, water activity (aw), gap, as well as water loss in salted pork were increased, and the results showed significant differences (p < 0.05). LF-NMR results indicated that NaCl was replaced by KCl, which can observably increased the mobility of water in the salted pork (p < 0.05). All indexes showed excellent correlation. NaCl was replaced by KCl, which affected the water retention capability of salted pork, because K+ promoted changes in the meat's physicochemical properties. The KCl replacement group presented higher water content, while displayed lower water retention capability.