Bottom Phase Research Articles

Using Rheology and Image Processing to Study the Effects of Cellulose Nanocrystal Sedimentation.

The effect of sedimentation on lyotropic liquid crystalline dispersions is both an interesting subject in colloidal science and is of practical importance for understanding changes that can occur during dispersion storage. This research explored how the seemingly subtle changes in average length resulting from a single sedimentation step affected the rheological properties and self-assembly of aqueous dispersions of sulfated cellulose nanocrystals. Sedimentation of a primarily isotropic aqueous cellulose nanocrystal dispersion for 1 month at ambient conditions resulted in an isotropic top phase and a biphasic bottom phase, which were separated for further study. Both atomic force microscopy measurements and intrinsic viscosities determined via Fedor's equation showed preferential fractionation of longer cellulose nanocrystals (CNCs) to the bottom phase. The effects of this fractionation on dispersion rheology and phase behavior were studied by preparing a range of concentrations from each phase. As expected, the concentration for the isotropic-biphasic phase transition was significantly lower for the bottom phase than for the top phase or parent dispersion. Rheological changes were generally subtle, but significant differences were seen in the storage modulus at concentrations approaching rheological gelation. Most notably, quantitative image processing showed that even this simple, single-step fractionation process had a significant impact on the relative proportion of tactoids and chiral helices with planar and homeotropic anchoring in self-assembled cellulose nanocrystal films. These results highlight the impact that changes in polydispersity due to sedimentation can have on the self-assembly of nanomaterial mesogens.

Sticky Science: Using Complex Coacervate Adhesives for Biomedical Applications.

Tissue adhesives are used for various medical applications, including wound closure, bleeding control, and bone healing. Currently available options often show weak adhesion or cause adverse effects. Recently, there has been an increasing interest in complex coacervates as medical adhesives. Complex coacervates are formed by mixing oppositely charged macromolecules that associate and undergo liquid-liquid phase separation, in which the dense bottom phase is the complex coacervate. Complex coacervates are strong and often biocompatible, and show strong underwater adhesion. The properties of the resulting materials are tunable by intrinsic factors such as polymer chemistry, molecular weight, charge density, and topology of the macromolecules, as well as extrinsic factors such as temperature, pH, and salt concentration. Therefore, complex coacervates are interesting new candidates for medical adhesives. In this review, it is described how complex coacervates form and how different factors influence their behavior. Next, an overview of recent studies on complex coacervates in the context of medical adhesives is presented. The application of complex coacervates as hemostatic or embolic agents, skin or bone repair adhesives, and soft tissue sealants is discussed. Lastly, additional possibilities for utilizing these materials in the future are discussed.

A novel deep eutectic solvent-based green extraction and purification of DPP-IV inhibitory peptides from tilapia (Oreochromis niloticus) viscera hydrolysate

The use of green and low-cost techniques to produce bioactive peptides with anti-diabetic properties from protein-rich fish waste is a sustainable way to manage agro-fishery and food industrial waste. This study investigated a novel ultrasound (UL) assisted deep eutectic solvent (DES) based extraction approach to recover bioactive protein-rich extracts from tilapia fish viscera waste under optimized conditions (52.52% ultrasound amplitude, 1:4 DES molar ratio, 25 min extraction time). The aqueous two-phase system (ATPS) method successfully concentrated the crude proteins in the top phase and back-extracted proteins to the bottom phase with a high recovery yield. Hydrolysis by Alcalase produced tilapia viscera protein hydrolysate (TVPH) with low molecular weight (MW) peptides and low dipeptidyl peptidase (DPP)-IV half-maximal inhibitory concentration (IC50) value of 1.57 ±0.16 mg/mL. Notably, TVPH-3 fraction and TVPH-3-2 sub-fraction exhibited appreciable DPP-IV IC50 values of 1.36 ±0.08 mg/mL and 0.42 ±0.01 mg/mL, respectively. Ultrafiltration combined with RP-HPLC enriched the DPP-IV inhibitory concentration of the individual protein fractions. TVPH-3-2 sub-fraction contained hydrophobic amino acids and peptide sequences with typical DPP-IV inhibitory peptide sequence motifs. The results presented in this study indicate that tilapia viscera biomass is a potential source for protein recovery aided with a green extraction approach, and tilapia viscera protein-derived hydrolysates have potential applications as a potent functional food ingredient for the management of metabolic diseases like type-2 diabetes.

A greener approach for physical separation of polycotton textile waste

Most textile waste ends up in the landfill. Clearly, enhancing textile recycling is urgently needed. For circularity, efficient means for separating the constituents of the textile blends is crucial. Targeting the popular polycotton textile blend, a method was developed to physically separate cotton and PET (polyethylene terephthalate) from waste textiles. First, the waste polycotton textile was milled into smaller fibers to mitigate entanglement. Then, leveraging the relatively higher hydrophilicity of cotton, three liquids (namely, water, mineral oil, and ethanol) were mixed to form a two-phase liquid-liquid system, which induced the preferential segregation of cotton to the water-rich bottom liquid phase. Factors studied included liquid composition and milling method. The best-performing liquid mixture allowed for 84.7 % of the cotton and 85.5 % of the PET from the waste polycotton (WPC) sample to be recovered respectively from the bottom liquid phase (BLP) and top liquid phase (TLP). The separation effectiveness can be further enhanced if fiber entanglement issue can be mitigated. The recovery of about 99.9 % PET and 86.7 % cotton from a prepared mixture of pure cotton and pure PET textile wastes is a case in point, demonstrating the efficacy of the method that is fast, at ambient condition, and does not require extensive chemicals. While the interwoven design of cotton and PET in textiles confers benefits like comfort and strength, the resulting entanglement is detrimental for circularity. SynopsisAn eco-friendly yet rapid two-phase liquid-liquid system was developed for separating polycotton textile fibers, aimed at enhancing sustainability and circularity

Achieving superior mechanical and corrosion properties in medium-thickness Ti-6Al-4 V alloy joints by back heating assisted friction stir welding below β-phase transformation temperature

The equiaxed microstructure formed below the β-phase transition point of Ti alloys generally exhibits an excellent balance of mechanical properties and corrosion resistance. However, this desirable microstructure is impossible to be obtained in fusion welded joints but is prospective to be achieved by the solid-state friction stir welding (FSW) technique. Unfortunately, it generally generates bottom defects and severe tool wear in medium-thickness Ti alloy joints when conventional FSW was conducted below the β-phase transition point. In this study, 6 mm thick Ti-6Al-4 V plates were joined by both the conventional FSW and back heating assisted FSW (BHAFSW). Defects caused by significant tool wear and bottom phase transition differences occurred in the conventional FSW. It was found that the hardness difference between the base material (BM) and the tool increased to 35.6 % from 500 °C to 900 °C. The back heating (150 °C) was used to control welding temperatures remaining the 900 °C, thus largely reducing the tool wear by increasing the hardness difference. In addition, the back temperature compensation increased the bottom temperature and controlled the phase transition position from the bottom to the middle of the joint. The shoulder pressure contributed to the compression of the defects, and the defects were eliminated by increasing the pressure at the phase transition position. A significantly refined equiaxed microstructure with an average grain size of ∼0.9 μm was achieved below the β-phase transition temperature in the stir zone via back heating assisted FSW, while a bimodal structure with an average grain size of 3.5 μm was formed near the β-phase transition temperature. Inconspicuous reduction of the strength was detected for the joints (98 % of the BM) which possess equiaxed microstructures, and the corrosion resistance of the joints was enhanced compared to the BM. This superior synergy of mechanical and corrosion properties exceeded the majority of Ti alloy joints previously reported. This study provided an effective method for obtaining medium-thickness Ti alloy joints with ultrafine equiaxial structures with superior mechanical properties and corrosion resistance.

Deep Eutectic Solvent-Based Aqueous Two-Phase Systems and Their Application in Partitioning of Phenol Compounds.

This work studies the partition of phenolic compounds, namely caffeic acid, syringic acid, vanillic acid, ferulic acid, and vanillin, in aqueous two-phase systems (ATPSs) formed by acetonitrile and deep eutectic solvents (DESs) based on choline chloride ([Ch]Cl) and carbohydrates (sucrose, d-glucose, d-mannose, arabinose, and d-xylose). The binodal curves built at 25 °C and 0.1 MPa using DES were compared with ATPS composed of [Ch]Cl and the same carbohydrates. The ability to form ATPS depends on the number and kind of hydroxyl groups in DES's hydrogen-bond donor compound (carbohydrates). ATPS based on DES showed biphasic regions larger than the systems based on [Ch]Cl and carbohydrates alone due to the larger hydrophilicity of DES. The ATPS were used to study the partition of the phenolic compounds. For all the systems, the biomolecules preferentially partitioned to the acetonitrile-rich phase (K > 1), and the best recovery in the top phase ranged between 53.36% (caffeic acid) and 90.09% (vanillin). According to the remarkable results, DES-based ATPS can selectively separate ferulic acid and vanillin for the top phase and syringic, caffeic, and vanillic acids for the bottom phase, achieving a selectivity higher than two.

Partitioning behavior of short DNA fragments in polymer/salt aqueous two-phase systems.

The development of liquid biopsy as a minimally invasive technique for tumor profiling has created a need for efficient biomarker extraction systems from body fluids. The analysis of circulating cell-free DNA (cfDNA) is especially promising, but the low amounts and high fragmentation of cfDNA found in plasma pose challenges to its isolation. While the potential of aqueous two-phase systems (ATPS) for the extraction and purification of various biomolecules has already been successfully established, there is limited literature on the applicability of these findings to short cfDNA-like fragments. This study presents the partitioning behavior of a 160 bp DNA fragment in polyethylene glycol (PEG)/salt ATPS at pH 7.4. The effect of PEG molecular weight, tie-line length, neutral salt additives, and phase volume ratio is evaluated to maximize DNA recovery. Selected ATPS containing a synthetic plasma solution spiked with human serum albumin and immunoglobulin G are tested to determine the separation of DNA fragments from the main plasma protein fraction. By adding 1.5% (w/w) NaCl to a 17.7% (w/w) PEG 400/17.3% (w/w) phosphate ATPS, 88% DNA recovery was achieved in the salt-rich bottom phase while over 99% of the protein was removed.

Investigating bottom phase extraction from aqueous two-phase systems for detecting bacteria using the lateral-flow immunoassay

Lateral-flow immunoassays (LFAs) can be used to diagnose urinary tract infections caused by Escherichia coli (E. coli) at the point of care. Unfortunately, urine samples containing dilute concentrations of E. coli can yield false negative results on LFAs. Our laboratory was first to implement aqueous two-phase systems (ATPSs) to preconcentrate samples into smaller volumes prior to their application on LFAs. This is achieved by manipulating the ratio of the volume of the top phase to that of the bottom phase (volume ratio; VR) and concentrating biomarkers in the bottom phase which, when applied to LFAs in fixed volumes, leads to corresponding improvements in sensitivity. This work is the first demonstration that the same LOD can be achieved irrespective of the VR when the entire bottom phase is added to LFAs. A custom 3D-printed device was also developed to decrease liquid handling steps. Across different VRs expected from patient urine variability, this diagnostic workflow successfully detected E. coli concentrations down to 2 × 105 colony-forming units (cfu) mL−1 in synthetic urine, demonstrating consistent 10-fold improvements in sensitivity compared to trials conducted without ATPS preconcentration. This method successfully addresses the variability of patient samples while remaining easy to use at the point of care.

Effects of CO₂ on the occurrence of decompression sickness: review of the literature.

Inhalation of high concentrations of carbon dioxide (CO₂) at atmospheric pressure can be toxic with dose-dependent effects on the cardiorespiratory system or the central nervous system. Exposure to both hyperbaric and hypobaric environments can result in decompression sickness (DCS). The effects of CO₂ on DCS are not well documented with conflicting results. The objective was to review the literature to clarify the effects of CO₂ inhalation on DCS in the context of hypobaric or hyperbaric exposure. The systematic review included experimental animal and human studies in hyper- and hypobaric conditions evaluating the effects of CO₂ on bubble formation, denitrogenation or the occurrence of DCS. The search was based on MEDLINE and PubMed articles with no language or date restrictions and also included articles from the underwater and aviation medicine literature. Out of 43 articles, only 11 articles were retained and classified according to the criteria of hypo- or hyperbaric exposure, taking into account the duration of CO₂ inhalation in relation to exposure and distinguishing experimental work from studies conducted in humans. Before or during a stay in hypobaric conditions, exposure to high concentrations of CO₂ favors bubble formation and the occurrence of DCS. In hyperbaric conditions, high CO₂ concentrations increase the occurrence of DCS when exposure occurs during the bottom phase at maximum pressure, whereas beneficial effects are observed when exposure occurs during decompression. These opposite effects depending on the timing of exposure could be related to 1) the physical properties of CO₂, a highly diffusible gas that can influence bubble formation, 2) vasomotor effects (vasodilation), and 3) anti-inflammatory effects (kinase-nuclear factor and heme oxygenase-1 pathways). The use of O₂-CO₂ breathing mixtures on the surface after diving may be an avenue worth exploring to prevent DCS.

Online monitoring of continuous aqueous two-phase flotation (ATPF) for the development of an autonomous control strategy

Aqueous two-phase flotation (ATPF) is a separation technique for isolating biological products such as enzymes from crude complex biosuspensions. The continuous operation mode of ATPF allows high throughput while maintaining a high separation efficiency. In this work, a laboratory plant for continuous ATPF with integrated online measurement technology is presented and ATPF experiments with the model enzyme phospholipase A2 are performed. Three electrical conductivity probes allow real time and spatially resolved characterization of phase mixing in the flotation tank caused by rising bubbles. UV/Vis spectroscopy is used to measure the enzyme concentration online at the top phase outlet. The equilibrium concentrations in the top and bottom phase are linearly dependent on the feed concentration, revealing a constant partition coefficient. The experimental results of this work provide the basis for the development of an autonomous feedback controller for the continuous ATPF process.

Synergized enzyme-ultrasound-assisted aqueous two-phase extraction and antioxidant activity validation of polysaccharides from tobacco waste

A powerful and innovative technique was developed to efficiently extract and refine polysaccharides from tobacco waste. This was achieved through a combination of enzyme and ultrasound-assisted extraction assisted aqueous two-phase extraction (EUAATPE). The formation of an aqueous two-phase system (ATPS) using various salts and ethanol was investigated. ATPS of 18.0 % (NH4)2SO4 (w/w) and 25.0 % ethanol (w/w) was chosen due to its favorable selection extraction ability and high recovery of 93.68 ± 0.40 %. By utilizing both single-factor experiments and response surface method (RSM), the key factors involved in the EUAATPE process were optimized. The optimal conditions were as follows: ultrasonic power 180 W, ultrasonic time 9 min, cellulase concentration 2.0 %, pectinase concentration 1.0 %, extraction temperature 50 °C, extraction time 1.5 h, and liquid-to-solid ratio 30:1 (g/g). Under the optimal conditions, the extraction yield of polysaccharides was 6.72 ± 0.11 (mg/g), and the purity of the polysaccharides from the bottom phase was 78.73 ± 3.17 %. EUAATPE resulted in a significant enhancement in the extraction yield and purity of polysaccharides from tobacco waste compared to traditional methods such as hot water extraction (HWE), ultrasound-assisted extraction (UAE) and enzyme-assisted extraction (EAE). Polysaccharides of tobacco waste obtained from various methods had analogous monosaccharide compositions, different molar ratio compositions and surface structure characteristics. Moreover, all polysaccharides exhibited a certain extent antioxidant activities and polysaccharides from the bottom phase (PBP) extracted by EUAATPE showed superior antioxidant activity. Hence, EUAATPE, being an innovative and eco-friendly extraction technique, presents a productive substitute for extracting and refining polysaccharides from discarded tobacco resources.

Bioactive flavonoids partitioning in a deep eutectic solvent/surfactant aqueous biphasic system: Efficiency and thermodynamics

The present study reports the partitioning behavior of three antioxidant flavonoids, including quercetin, chrysin, and daidzein, in an aqueous biphasic system (ABS) formed using a deep eutectic solvent (DES), a non-ionic surfactant (Triton X-100), and water. The efficiency of this ABS in partitioning the flavonoids was investigated by calculating the partition coefficients and recovery efficiencies at different temperatures. The experimental results showed that in all ABSs the flavonoids under study tend to transfer effectively into the surfactant-rich bottom phase in the order of chrysin > quercetin > daidzein. From analyzing the effect of temperature on the partitioning of antioxidants, thermodynamic transfer properties consists of molar Gibbs energy ∆Gm,Flav°, molar enthalpy ∆Hm,Flav° and molar entropy ∆Sm,Flav°were calculated. It is inferred from the results that partitioning of the flavonoids is spontaneous and endothermic. So, increasing the partition coefficient and recovery percentage of the flavonoids by increasing temperature can be explained by the endothermic nature of partitioning process. Finally, molecular interactions between the flavonoid molecules and ABS components were estimated by applying group contribution method. Also, it can be concluded that the extent of interactions between chrysin and components of the ABS (especially the surfactant TX-100) is more than flavonoids quercetin and daidzein.

Primary recovery strategies of low‐molecular‐weight toxins from Crotalus molossus nigrescens and Crotalus atrox using aqueous two‐phase and three‐phase partition systems

AbstractBACKGROUNDRattlesnake venoms are a complex source of different toxin families with biotechnological and biomedical applications. However, the complexity of the sample and the low abundance of some toxins can restrict their study and applications. Toxin isolation usually requires multiple chromatographic steps, implying elevated operative costs and processing times. This raises the need for recovery and enrichment of those proteins and peptides. For that reason, we tested two liquid–liquid separation methods – aqueous two‐phase systems (ATPS) and three‐phase partition (TPP) – since these two alternatives have shown great potential for the primary recovery of different toxin families from rattlesnake venoms.RESULTSPolyethylene glycol (PEG)–citrate and ionic liquid (IL)–potassium phosphate ATPS and TPP based on t‐butanol and ammonium sulfate were used to partition different toxin families from Crotalus molossus nigrescens and C. atrox venoms. PEG–citrate allowed a selective partition of proteins between both phases. The best enrichment case was observed with a myotoxin band (6.6 kDa) in the PEG‐rich phase from 2% to 41.3% of abundance. In IL–potassium phosphate systems, proteins showed a preference towards the IL‐rich phase with no selective partition. In TPP, proteins were partitioned mainly to the bottom phase and interphase, but serine proteases (29.1 kDa) were enriched from 3.7% to 56.6% in the top phase.CONCLUSIONThe present study demonstrated that PEG–citrate ATPS and TPP separation methods can generate a selective partition of some toxin families from rattlesnake venoms. These enrichment methods will facilitate the isolation of toxins, from animal venoms, that are relevant for biotechnological and biomedical applications. © 2024 Society of Chemical Industry (SCI).

New aqueous two-phase system formed by piperazinium-based surface-active ionic liquid for extraction of dyes

Aqueous two-phase systems (ATPSs) as alternatives to traditional liquid–liquid extraction systems have been used intensively in recent years. In this work, a new ATPS composed of a piperazinium-based surface-active ionic liquid (SAIL), 1-(2-hydroxyethyl)piperazinium laurate ([HEP][C11CO2]), and a commercial cationic surfactant, dodecyldimethylbenzylammonium chloride (DDBAC) was prepared. The phase diagram for the ternary system DDBAC + [HEP][C11CO2] + H2O was determined, and the effects of composition and temperature on phase behaviors and properties were investigated. Phase separation was found spontaneous and thermodynamically favored when the mass fraction of water (w3) exceeded 0.60, primarily due to the salting-out of the hydrophilic ions [HEP]+ and Cl− in the bottom phase. Micelles were observed in the top phase where high concentrations of the hydrophobic ions [DDBA]+ and [C11CO2]− were present. Increasing the water content at a fixed surfactant-to-SAIL molar ratio resulted in a decreased top phase volume, while the extraction efficiency (EE) and the distribution coefficient (D) were both increased for extractions of Basic Blue 7 and Allura Red AC. When w3 reached 0.96 and the initial concentration of dye was below 1 × 10−4 mol·L−1, the EE values exceeded 98 % with all the D values surpassing 100, indicating the promising potential for SAIL-ATPS applications.

Effect of steel matrix with different C content on the growth mechanism, microstructure and properties of the chromized layer

The C content of the steel matrix has significant influence on the growth mechanism, microstructure and properties of the chromized layer. However, the relevant research literature is scarce. In this paper, seven kinds of low carbon alloy steels with C content ranging from 0.08 wt% to 0.45 wt% were selected as matrix for chromizing experiments under the same parameters. The effects of matrix C content on the growth mechanism, growth rate, structure and properties of the chromized layer were discussed. The results show that the chromized layer is composed of outer porous (Cr, Fe)23C6 and (Cr, Fe)7C3 carbides layer and inner dense FeCr phase layer for matrix with C content lower than or equal to 0.2 wt%. While when the matrix C content is >0.2 wt%, the chromized layer becomes three-layer structure: the surface (Cr, Fe)23C6 phase layer, the middle (Cr, Fe)7C3 phase layer and the bottom FeCr solid solution phase layer. The structure and thickness of Cr23C6 phase layer formed in the early stage of chromizing play a decisive role in the inward diffusion of surface adsorbed Cr atoms and the growth rate of the permeated layer. With the C content of the matrix increases from low(0.08wt%C) to high(0.45wt.%C), the dense layer phases in chromized samples gradually changes from FeCr alloy phase with BCC structure to (Cr, Fe)23C6 and (Cr, Fe)7C3 carbides. And the wear resistance of the chromized layer increase. However, when the matrix C content is above 0.4 wt%, the structure and phases of the chromized layer are almost not affected by the matrix C content, so are the thickness and wear resistance. The results are helpful to the selection of steel matrix composition for chromizing and the optimization of chromizing process.

The waveguide invariant close to the deep-water bottom

Waveguide invariant, denoted by β, describes the dispersive nature of the underwater acoustic waveguide. In most range-independent shallow-water waveguides β≈1, whereas β is no longer constant in deep water and is more appropriately described by a distribution. This paper investigates the characteristic of β close to the deep-water bottom. The adiabatic normal mode theory is used to analyze β resulting from the bottom-bounce dominated acoustic field qualitatively. Then, the Wentzel–Kramers–Brillouin approximation with bottom reflection phase shift and the dominance of the acoustic field by groups of modes are employed to amend the original waveguide invariant theory. The interference between the phase-compensated dominant modal groups is calculated to obtain the value of β and analyze the distribution in the two-dimensional spectrum of the interference pattern. For a typical deep-water waveguide, both qualitative and quantitative analyses indicate that β≈1 when close to the bottom instead of a distribution. Simulation and experiment data demonstrate that the interference between phase-compensated dominant modal groups produces particular structure in the two-dimensional spectrum resulting from β being approximately equal to 1. The characteristic of β proposed in this paper has potential application in remote ranging the underwater acoustic source in deep water, which is verified using experimental data.

Assessment of the significance of immunoenzyme test-system for determining antiendotoxic immunity against the endotoxin of gram negative bacteria

The purpose of the study was to determine the specificity and sensitivity of the immunoenzymatic test system that detects antibodies against the antigens of these bacteria in order to evaluate antiendotoxic immunity against GShPB endotoxins. It was found that flat bottom polystyrene solid phase carrier was selected for the proposed experimental test system for the detection of endotoxins of these bacteria by IFA method. The sensitivity of the recommended test system was 75% in colon dysbiosis, 76% in acute tonsillitis, 89% in acute bronchitis, and 95% in urinary tract infections, and the specificity was 5-25%, thus the diagnostic value of this test system it was proved for the first time.

Penicillium citrinum CFAM 521 Isolated From the Amazon Region: A Novel Source of a Fibrinolytic Enzyme.

Fibrinolytic agents are essential in treating thrombosis, playing a critical role in improving survival rates in cardiovascular diseases. Microbial fibrinolytic proteases have emerged as promising alternatives due to their affordability, specificity, lower toxicity, and reduced side effects. Consequently, the search for microorganisms capable of producing these enzymes has gained significant economic importance in the pharmaceutical industry. This study reports and characterizes a novel fibrinolytic enzyme produced by Penicillium citrinum CFAM 521, a strain isolated from the Amazon region. The enzyme was purified using a polyethylene glycol (PEG)-phosphate salt aqueous two-phase system (ATPS). The effects of PEG molecular weight, PEG concentration, and phosphate concentration on the protease partition coefficient (K) were evaluated through a 22 full factorial design. The enzyme exhibited both fibrinolytic and fibrinogenolytic activities. After partitioning in a two-phase system with 10% (w/w) PEG and 15% (w/w) sodium phosphate, the fibrinolytic proteases were predominantly retained in the salt-rich bottom phase (K = 0.33). The enzyme has a molecular weight of 34 kDa, with optimal pH and temperature at 9°C and 37°C, respectively. Inhibitory analysis confirmed that it is a serine protease, and its activity was enhanced by the addition of Mn2+. Notably, the enzyme exhibited no hemolytic activity. Therefore, P. citrinum CFAM 521 represents a novel source of fibrinolytic enzymes, highlighting its potential as an alternative for the development of thrombolytic agents.

A structural study on a specific Li-ion ordered complex in dimethyl carbonate-based dual-cation electrolytes.

Dimethyl carbonate (DMC) is a linear carbonate solvent commonly used as an electrolyte for electric double-layer capacitors (EDLCs) and Li-ion batteries. However, there are serious problems with the use of DMC as an electrolyte solvent: (1) low ionic conductivity when using Li salts (e.g. LiBF4) and (2) liquid-liquid phase separation when using spiro-type quaternary ammonium salts (e.g. SBPBF4). Dual-cation electrolytes, i.e., bi-salt (SBPBF4 and LiBF4) in DMC, are promising candidates to avoid the phase separation issue and to enhance the total and Li+ conductivities. Herein, we reported a specific Li-ion structure in DMC-based dual-cation electrolytes by combining high-energy X-ray total scattering (HEXTS) and all-atom molecular dynamics (MD) simulations. Quantitative radial distribution function analysis based on experimental and simulation results revealed that the phase-separated SBPBF4/DMC (i.e., the bottom phase of 1 M SBPBF4/DMC) forms long-range ion ordering based on the structured SBP+-BF4- ion pairs. When adding LiBF4 salt into SBPBF4/DMC (i.e., dual-cation electrolyte), the ordered SBP+-BF4- structure disappeared owing to the formation of Li-ion solvation complexes. We found that in the dual-cation electrolyte Li ions form multiple Li+-Li+ ordered complexes in spite of relatively low Li-salt concentration (1 M), being a promising Li+-conducting medium with reduced Li salt usage and low viscosity.

Low-Viscous, Dilute Phase Adhesive from Dense Polyphenolic Coacervates of Poly(vinyl alcohol) and Tannic acid.

This study explores a polyphenolic coacervate, named VATA, formed by poly(vinyl alcohol) (PVA) and tannic acid (TA). Distinct from conventional studies that have focused on the bottom, dense phase of coacervates, this research emphasizes the top, dilute phase, low-viscous coacervate liquid termed liquid-VATA (l-VATA). Due to TA's capability of intermolecular association as well as adhesiveness, phenomena not typically observed in the upper dilute phase of standard polyelectrolyte-based coacervates are revealed. At first glance, the dilute phase l-VATA coacervate resembles a water-like, low-viscous mixture solution of PVA, TA, and PVA/TA complexes. However, analysis shows that nearly all of the TA molecules associate with PVA chains, forming PVA/TA complexes. Furthermore, supraparticular association was observed between PVA/TA complex nanoparticles upon applying external shear force. A broad survey of shear rate and strain showed that the solution exhibited sequential shear-thickening, followed by shear-thinning behavior. The water-like, low viscosity of l-VATA unexpectedly reveals robust adhesiveness and thus able to lift an entire mouse using just a single human hair strand. Even in cases of failure, no interfacial failure was detected between mouse and human hair. In addition to enabling hair-to-hair bonding, our study also showcases the efficacy of l-VATA in facilitating hair-to-skin adhesion. The results illustrate how the lower viscosity of l-VATA can be exploited for a wide range of industrial and cosmetic applications, allowing the formulation of thin, uniform adhesive layers, something unachievable with the dense, viscous VATA glue. Thus, this study highlights the importance of investigating the top dilute phase of coacervates, shedding light on an area often underestimated compared to the bottom dense phase reported in prevalent coacervate studies.