Dimethyl Sulfoxide Solution Research Articles

Optical Clearing of Ex Vivo Adipose Tissue.

The paper focuses on the development of technology of adipose tissue optical clearing using different complex hyperosmotic optical clearing agents and tissue permeability enhancers. To quantify optical clearing efficiency, reduced scattering coefficient was estimated from the ex vivo spatially resolved backreflectance measurements using a multi-distant fiber optical device. Tissue morphology modification was monitored with the help of histological studies. Kinetics and efficiency of the optical clearing were evaluated for ex vivo abdominal fat tissue at action of dimethyl sulfoxide, diatrizoic acid, metrizoic acid, sucrose, and fructose solutions accompanied by tissue permeability enhancers, such as various modes of fractional laser microablation and sonophoresis and their combinations. Histological studies allowed us to find agents that cause minimal morphological changes of the adipose tissue. Maximal optical clearing efficiency of 83.5% was observed for the samples subjected to action of the fructose-ethanol solution during 90 min in combination with gentle modes of fractional laser microablation and sonophoresis.

Synthesis of Amorphous Cellulose Derivatives via Michael Addition to Hydroxyalkyl Acrylates for Thermoplastic Film Applications.

The aim of this study is to prepare new cellulose derivatives that show good feasibility and processability. Accordingly, in this study, we demonstrate Michael addition to hydroxyalkyl acrylates, that is, 2-hydroxyethyl and 4-hydroxybutyl acrylates (HEA and HBA, respectively), to synthesize amorphous cellulose derivatives under alkaline conditions. The reactions were carried out in the presence of LiOH in ionic liquid (1-butyl-2,3-dimethylimidazolium chloride)/N,N-dimethylformamide (DMF) solvents at room temperature or 50 °C for 1 h. The Fourier transform infrared and 1H nuclear magnetic resonance (NMR) measurements of the products supported the progress of Michael addition; however, the degrees of substitution (DS) were not high (0.3-0.6 for HEA and 0.6 for HBA). The powder X-ray diffraction analysis of the products indicated their amorphous nature. The cellulosic Michael adduct from HEA with DS = 0.6 was swollen with high polar organic liquids, such as DMF. In addition to swelling with these liquids, the cellulosic Michael adduct from HBA was soluble in dimethyl sulfoxide (DMSO), leading to its 1H NMR analysis in DMSO-d6. This adduct was found to form a cast film with flexible properties from its DMSO solutions. Furthermore, films containing an ionic liquid, 1-butyl-3-methylimidazolium chloride, showed thermoplasticity. The Michael addition approach to hydroxyalkyl acrylates is quite effective to totally reduce crystallinity, leading to good feasibility and processability in cellulosic materials, even with low DS. In addition, the present thermoplastic films will be applied in practical, bio-based, and eco-friendly fields.

Elimination of mutagenic contaminants from water using cellulose bearing ferrous-phthalocyanine

BackgroundWe previously investigated methods for separating mutagenic contaminants from aqueous solutions using cellulose-bearing covalently bound trisulfo-Cu-phthalocyanine (blue cotton and blue rayon). Mutagenic contaminants with three or more fused aromatic rings in their structures were adsorbed onto blue cotton and rayon. Since Cu-phthalocyanine is considered an unsuitable absorption ligand for byproducts of water chlorination, such as 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (Mutagen X or MX), we investigated the development of a new material for the elimination of MX from aqueous solvents.ResultsWe selected green cellulose powder bearing ferrous phthalocyanine (FePh), hereafter referred to as green cellulose or GP, as the candidate material. GP is composed of cationized cellulose (white cellulose, WP) and FePh tetracarboxylic acid. The mutagenicity of MX dissolved in buffer or dimethyl sulfoxide (DMSO) solution significantly decreased after treatment with GP. The effects of GP on the elimination of MX from the solvent were very close to being expired after 70 cycles of repeated adsorption of the same GP, and the capacity of GP for MX removal was estimated to be exhausted after 120 cycles of repeated adsorption based on the extrapolation of the obtained result; thus, the interacting ligands on GP may be saturated after complete MX adsorption. The mutagenicity of MX dissolved in aqueous buffer significantly decreased after treatment at pH7.4 but not at pH 4.0. Since MX is dissociated to be the anionic form at pH 6 or higher, the negative charge of MX in the buffer at pH 7.4 may interact with the positive charge of ferrous ions in GP to create a linkage between MX and GP. After GP adsorbed MX, mutagenicity was extracted with water or acetonitrile and recovered in the eluent. Thus, the reversible interaction between MX and FePh may have caused adsorption of MX onto GP.ConclusionGP could be used as a new eliminator and recovery agent for MX in chlorinated drinking water. Developing new materials for the removal and recovery of agents for the detection of mutagenic contaminant-related chlorination in water is beneficial for environmental health.

Over 10% Efficiency Pure Sulfide Kesterite Solar Cells on Transparent Electrode with Cd-Ag Co-Alloying.

The environmentally friendly elements composed of high bandgap pure sulfide Cu2ZnSnS4 (CZTS) semiconductor has broad prospects for building integrated photovoltaic, double-sided, and semi-transparent solar cells when fabricated on transparent substrates. The key issues limiting the performance of CZTS solar cells are poor absorber quality and unfavorable band energy alignment causing serious charge carrier recombination. Here, thefabrication of CZTS solar cells are reported on fluorine-doped tin oxide (FTO) substrates from dimethyl sulfoxide solution and the effects of the Cd and Ag alloying on device performance. Characterizations show that Cd alloying greatly decreases defect concentration and converts Cliff-type band alignment to favorable Spike-type, leading to greatly improved current density. Further, Ag alloying eliminates near-horizontal grain boundaries and passivates defects in both bulk and heterojunction interface, resulting in a champion device with a power conversion efficiency of 10.3%, the highest efficiency pure sulfide CZTS solar cell on FTO substrate. The results demonstrate the great application potential of pure sulfide kesterite solar cells.

Investigation of the Application of Reduced Graphene Oxide-SPION Quantum Dots for Magnetic Hyperthermia.

Integrating hyperthermia with conventional cancer therapies shows promise in improving treatment efficacy while mitigating their side effects. Nanotechnology-based hyperthermia, particularly using superparamagnetic iron oxide nanoparticles (SPIONs), offers a simplified solution for cancer treatment. In this study, we developed composites of SPION quantum dots (Fe3O4) with reduced graphene oxide (Fe3O4/RGO) using the coprecipitation method and investigated their potential application in magnetic hyperthermia. The size of Fe3O4 nanoparticles was controlled within the quantum dot range (≤10 nm) by varying the synthesis parameters, including reaction time as well as the concentration of ammonia and graphene oxide, where their biocompatibility was further improved with the inclusion of polyethylene glycol (PEG). These nanocomposites exhibited low cytotoxic effects on healthy cells (CHO-K1) over an incubation period of 24 h, though the inclusion of PEG enhanced their biocompatibility for longer incubation periods over 48 h. The Fe3O4/RGO composites dispersed in acidic pH buffer (pH 4.66) exhibited considerable heating effects, with the solution temperature increasing by ~10 °C within 5 min of exposure to pulsed magnetic fields, as compared to their dispersions in phosphate buffer and aqueous dimethylsulfoxide solutions. These results demonstrated the feasibility of using quantum dot Fe3O4/RGO composites for magnetic hyperthermia-based therapy to treat cancer, with further studies required to systematically optimize their magnetic properties and evaluate their efficacy for in vitro and in vivo applications.

In vitro anthelmintic activity of hydroethanolic extract of Artemisia herba aba and Juniperus phoenicea on abomasal Teladorsagia circumcincta of sheep.

The present study aimed to evaluate the in vitro anthelmintic activity of Juniperus phoenicea and Artemisia herba-alba against abomasal nematodes collected from naturally infected sheep. The anthelmintic activities of the extracts were assessed using egg hatch inhibition (EHIA) and adult motility assays (AMA) against Teladorsagia circumcincta. The parasites were stored in phosphate-buffered saline (PBS) until the in vitro assessment began. The leaf powders of J. phoenicea and A. herba-alba were extracted using the maceration procedure. Briefly, the leaf powders were mixed with a sufficient quantity of 99% ethanol and distilled water (80%/20%). The extracts were dissolved in a 3% dimethyl sulfoxide (DMSO) solution to improve water solubility. The hydroethanolic extracts were tested at concentrations of 1.562, 3.125, 6.25, 12.5, and 25 mg/ml. Adult motile worms were individually subjected to each treatment at laboratory temperature. The PBS and albendazole (25 mg/ml) were prepared and used as negative and positive controls, respectively. The test was repeated five times for each concentration. The results showed that both plant extracts exhibited anthelmintic effects. A. herba-alba extract at 25 mg/ml inhibited the motility of all T. circumcincta adult worms within 1 hour of administration, while J. phoenicea extract caused 100% mortality of adult worms after 4 hours at the same concentration. Neither of the extracts, at 1.562 mg/ml, had any inhibitory effect on motility. At 25 mg/ml, the A. herba-alba (98.67%) and J. phoenicea (96.24%) showed high activity with an inhibitory effect on hatchability compared to the other tested concentrations. The findings of the present study showed that hydroethanolic extracts of A. herba-alba and J. phoenicea leaves had in vitro anthelmintic activity on eggs and adult T. circumcincta of sheep.

Preparation of chitosan-based macromolecular antioxidant with high-efficiency free radical scavenging ability to improve the antioxidative properties of styrene-butadiene rubber/silica composites

To address the disadvantages of traditional rubber antioxidants with low molecular weight such as easy migration, poor extraction resistance, low thermal stability and antioxidant efficiency, in this work, we first prepared an antioxidant containing primary and secondary antioxidant groups (MC-MPA) through thiol-ene click reaction between N-(4-aminophenyl)maleimide (MC) and 3-mercaptopropionic acid (MPA). Then, we synthesized a chitosan-based macromolecular antioxidant with long-chain alkene, aromatic secondary amine, and thioether groups (COS-UC-MC-MPA) by sequentially grafting functional compounds 10-undecanonyl chloride (UC) and antioxidant MC-MPA onto natural macromolecular polymer chitosan (COS). The free radical scavenging ability of COS-UC-MC-MPA was assessed by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and the results demonstrated that COS-OC-MC-MPA has high scavenging rate of 76.5 % for DPPH free radicals after 1 min of contact with DPPH dimethyl sulfoxide solution, showing excellent free radical scavenging ability. In addition, the results of accelerated thermo-oxidative aging test, thermogravimetric (TG) test, kinetic analysis of thermal-oxidative degradation, extraction resistance test, and volatilization resistance test indicated that COS-UC-MC-MPA with superior migration resistance and volatilization resistance could effectively enhance the antioxidative properties, thermal stability and thermal-oxidative stability of rubber composites. Moreover, the results of rubber processibility analysis (RPA) test and scanning electron microscopy (SEM) implied that the addition of COS-UC-MC-MPA is also conductive to improving the dispersibility of silica in rubber matrix. This study supplies a new perspective for the preparation of environmentally friendly and highly efficient macromolecular antioxidants for rubber composites.

8.36% Efficient CZTS Solar Cells on Transparent Electrode via Solution Processing

High‐bandgap Cu2ZnSnS4 (CZTS) thin film solar cells on transparent electrodes show favorable characteristics for new photovoltaic application scenarios including building‐integrated photovoltaics, vehicle‐integrated photovoltaics, and top cell for tandem structure. However, the efficiency of pure sulfide kesterite CZTS thin film solar cells on transparent substrates lags behind that on traditional Mo substrates. Herein, fabrication of high‐quality CZTS absorber films and efficient solar cells on fluorine‐doped tin oxide substrates from dimethyl sulfoxide solution is reported. The formation of harmful secondary phases in CZTS film is suppressed by simply adjusting the chemical stoichiometry in the precursor solution, leading to the development of 5.88% CZTS solar cells. Sodium (Na) doping further promotes grain growth and suppresses secondary phase, contributing to the reduced interface recombination and improved device performance. A champion device with an efficiency of 8.36% has been achieved with 1% Na doping, underscoring the significance of the solution process in achieving highly efficient kesterite solar cells on transparent electrodes.

In-Depth XANES and EXAFS Characterization of the Ag+ Ion Coordination in Dimethyl Sulfoxide Solution.

X-ray absorption near-edge structure (XANES) spectroscopy has been used, in conjunction with extended X-ray absorption fine structure (EXAFS), to determine the coordination structure of the Ag+ ion in a dimethyl sulfoxide (DMSO) solution. From the EXAFS data analysis, the Ag-O first shell distance in DMSO was found to be 2.31(3) Å, with 4.1(5) oxygen atoms surrounding the Ag+ ion, in fair agreement with previous results. This technique did not allow us to determine the geometry of the 4-fold coordination complex and a quantitative analysis of the XANES region was carried out to shed light on this issue. The XANES data analysis confirmed the presence of a four-coordinated complex, unambiguously showing that a regular tetrahedral [Ag(DMSO)4]+ complex is formed when silver triflate is dissolved in DMSO solution.

A3B Zn(II)-Porphyrin-Coated Carbon Electrodes Obtained Using Different Procedures and Tested for Water Electrolysis

In the context of water electrolysis being highlighted as a promising technology for the large-scale sustainable production of hydrogen, the water-splitting electrocatalytic properties of an asymmetrically functionalized A3B zinc metalated porphyrin, namely, Zn(II) 5-(4-pyridyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin, were evaluated in a wide pH range. Two different electrode manufacturing procedures were employed to outline the porphyrin’s applicative potential for the O2 and H2 evolution reactions (OER and HER). The electrode, manufactured by coating the catalyst on a graphite support from a dimethylsulfoxide solution, displayed electrocatalytic activity for the OER in an acidic electrolyte. An overpotential value of 0.44 V (at i = 10 mA/cm2) and a Tafel slope of 0.135 V/dec were obtained. The modified electrode that resulted from applying a Zn(II)-porphyrin-containing catalyst ink onto the same substrate type was identified as a bifunctional water-splitting catalyst in a neutral medium. OER and HER overpotentials of 0.78 and 1.02 V and Tafel slopes of 0.39 and 0.249 V/dec were determined. This is the first Zn(II)-porphyrin to be reported as a heterogenous bifunctional water-splitting electrocatalyst in neutral aqueous electrolyte solution and is one of very few porphyrins behaving as such. The TEM analysis of the porphyrin’s self-assembly behavior revealed a wide variety of architectures.

CEST effect of dimethyl sulfoxide at negative offset frequency.

Dimethyl sulfoxide (DMSO) has wide biomedical applications such as cryoprotectant and hydrophobic drug carrier. Here, we report for the first time that DMSO can generate a distinctive chemical exchange saturation transfer (CEST) signal at around -2ppm. Structural analogs of DMSO, including aprotic and protic solvents, also demonstrated CEST signals from -1.4 to -3.8ppm. When CEST detectable barbituric acid (BA) was dissolved in DMSO solution and was co-loaded to liposome, two obvious peaks at 5 and -2ppm were observed, indicating that DMSO and related solvent system can be monitored in a label-free manner via CEST, which can be further applied to imaging drug nanocarriers. With reference to previous studies, there could be molecular interactions or magnetization transfer pathways, such as the relayed nuclear Overhauser enhancement (rNOE), that lead to this detectable CEST contrast at negative offset frequencies of the Z-spectrum. Our findings suggest that small molecules of organic solvents could be involved in magnetization transfer processes with water and readily detected by CEST magnetic resonance imaging (MRI), providing a new avenue for detecting solvent-water and solvent-drug interactions.

Establishing a method for the cryopreservation of viable peripheral blood mononuclear cells in the International Space Station

The analysis of cells frozen within the International Space Station (ISS) will provide crucial insights into the impact of the space environment on cellular functions and properties. The objective of this study was to develop a method for cryopreserving blood cells under the specific constraints of the ISS. In a ground experiment, mouse blood was directly mixed with a cryoprotectant and gradually frozen at −80 °C. Thawing the frozen blood sample resulted in the successful recovery of viable mononuclear cells when using a mixed solution of dimethylsulfoxide and hydroxyethyl starch as a cryoprotectant. In addition, we developed new freezing cases to minimize storage space utilization within the ISS freezer. Finally, we confirmed the recovery of major mononuclear immune cell subsets from the cryopreserved blood cells through a high dimensional analysis of flow cytometric data using 13 cell surface markers. Consequently, this ground study lays the foundation for the cryopreservation of viable blood cells on the ISS, enabling their analysis upon return to Earth. The application of this method in ISS studies will contribute to understanding the impact of space environments on human cells. Moreover, this method may find application in the cryopreservation of blood cells in situations where research facilities are inadequate.

Lithium-Ion Transport Properties in DMSO and TEGDME: Exploring the Influence of Solvation through Molecular Dynamics and Experiments.

This study explores the properties of aprotic electrolytes via the application of experimental methods, including nuclear magnetic resonance spectroscopy and electrochemical techniques, along with molecular dynamic modeling. The aim is to provide a quantitative description of the physico-chemical properties of two well-established electrolytes (case studies), each exhibiting significantly distinct dielectric properties: a LiTFSI (Lithium bis(trifluoromethanesulfonyl)imide) solution in dimethyl sulfoxide (DMSO, dielectric constant =46.68) and a LiTFSI solution in tetraethylene glycol dimethyl ether (TEGDME, =7.71). We obtained a comprehensive insight into the properties of the electrolytes at both the macroscopic-collective and molecular levels with particular emphasis on the interactions between the Li ions and solvent molecules. We discovered remarkable disparities in the structural arrangements, solvation behaviors, and bulk-related properties of these electrolyte systems, particularly in response to temperature changes.

Effect of Salt Variability on the Low-Temperature Metal-Catalyzed Graphitization of PAN/DMSO Solutions for the Synthesis of Nanostructured Graphitic Carbon

Graphitic carbon plays a pivotal role in numerous technological applications, including energy storage, energy conversion, and different fields of material science. The transformation of amorphous carbon into graphitic carbon, a process known as graphitization, is important for optimizing the properties of carbon materials. In this study, we explore the catalytic graphitization of polyacrylonitrile (PANs) using various metal salts (LiNO3, Ca(NO3)2·4H2O, and Ni(NO3)2·6H2O). We prepared dimethyl sulfoxide (DMSO) solutions of PAN with different salt concentrations of 5, 10, and 15 wt.%. The different prepared metal salt-mixed PAN/DMSO solutions were dried at 45 °C and this was followed by carbonization processes at 950 °C, with a heating rate of 1 °C min−1 for 1 h under an N2 atmosphere. The resulting graphitic carbon was characterized to determine the influence of salt type and concentration on the degree of graphitization. Our findings provide valuable insights into PAN-derived graphitic carbon’s structural and compositional properties. This work underscores the influence of salt concentration in optimizing the graphitization process, offering a pathway to design facile and cost-effective graphitic carbon materials.

Controlled Interlayer Binding and Healing Improve the Transverse Properties of Upcycled Disposable Waste Wood.

Recovery and reuse of bulk waste wood are particularly challenging because of usage defects and contaminations. Here, we present a robust and efficient strategy for regenerating used wood veneers into high-performance structural materials through micro/nano interface manipulation. Our approach involves using cellulose-based interlayers to bind together two waste wood plates without an external adhesive by partially dissolving and regenerating the interlayer using a solution of ionic liquids and dimethyl sulfoxide. The mechanical properties of the regenerated wood exceed that of natural wood, displaying over a 16 and 20 times increase in transverse tensile strength and modulus, respectively, and 4-6 times improvement in longitudinal tensile strength and modulus. Nanoscale mechanical analyses show that the improvement is possible as a result of several factors, including the robust network structure of the interlayer, the good adhesion at the wood-interlayer interface, the compacted wood structure, and the low stiffness and deformation gradients between the interlayer and the wood structure. The interlayers can be created from waste papers and wood particles by taking advantage of the nanofibrillar structure of cellulose.

Bactericidal Effect of Different Photochemical-Based Therapy Options on Implant Surfaces-An In Vitro Study.

Objectives: Photochemical systems are frequently recommended as an adjuvant treatment option in peri-implantitis therapy. The aim of the present study was to evaluate the efficacy of these treatment options, as well as a novel curcumin-based option, in a biofilm model on implants. Methods: Eighty dental implants were inoculated with an artificial biofilm of periodontal pathogens and placed in peri-implant pocket models. The following groups were analyzed: I, photodynamic therapy (PDT); II, PDT dye; III, curcumin/DMSO + laser; IV, curcumin/DMSO only; V, dimethyl sulfoxide (DMSO) only; VI, photothermal therapy (PTT); VII, PTT dye; VIII, control. After treatment, remaining bacterial loads were assessed microbiologically using quantitative real-time polymerase chain reaction analysis. Results: The PDT, PTT, and DMSO treatment methods were associated with statistically significant (p < 0.05) improvements in germ reduction in comparison with the other methods and the untreated control group. The mean percentage reductions were as follows: I (PDT) 93.9%, II (PDT dye) 62.9%, III (curcumin/DMSO + laser) 74.8%, IV (curcumin/DMSO only) 67.9%, V (DMSO) 89.4%, VI (PTT) 86.8%, and VII (PTT dye) 66.3%. Conclusions: The commercially available PDT and PTT adjuvant treatment systems were associated with the largest statistically significant reduction in periopathogenic bacteria on implant surfaces. However, activation with laser light at a suitable wavelength is necessary to achieve the bactericidal effects. The use of curcumin as a photosensitizer for 445 nm laser irradiation did not lead to any improvement in antibacterial efficacy in comparison with rinsing with DMSO solution alone.

Analysis of cryopreservation media thermophysical characteristics after ultra-rapid cooling through differential scanning calorimetry

Cryoprotective agents play a critical role in minimizing cell damage caused by ice formation during cryopreservation. However, high concentrations of CPAs are toxic to cells and tissues. Required concentrations of CPAs can be reduced by utilizing higher cooling and warming rates, but insight into the thermophysical properties of biological solutions in the vitrification method is necessary for the development of cryopreservation protocols. Most studies on thermophysical properties under ultra-rapid cooling conditions have been qualitatively based on visualization. Differential scanning calorimetry methods are ideal for studying the behavior of biomaterials in various freezing conditions quantitatively and accurately, though previous studies have been predominantly restricted to slower cooling rates. Here, we developed an ultra-rapid cooling method for DSC that can achieve minimal cooling rates exceeding 2000 °C/min. We investigated the thermophysical vitrification behavior of ternary solutions of phosphate buffer saline (1X), dimethyl sulfoxide or glycerol and ice blocking polymers (X-1000 or Z-1000). We quantified the impact of solute concentration on ice crystal formation during rapid cooling. Our findings support the expectation that increasing the solute concentration reduces the amount of ice formation, including devitrification. Devitrification increases from 0 % to 40 % (v/v) Me2SO and then reduces significantly. The relative amounts of devitrification to the total ice formation are 0 %, 60 %, 0 % in 20 %, 40 %, 60 % (v/v) Me2SO, and 2 %, 48 %, 49 % in 20 %, 40 %, 60 % (v/v) glycerol, respectively. The results suggest that at low concentrations, such as below 20 % (v/v) for Me2SO or glycerol, increasing the warming rate after ultra-rapid freezing is not essential to eliminate devitrification. Furthermore, ice blocking polymers do not reduce ice formation substantially and cannot eliminate devitrification under ultra-rapid cooling conditions. In conclusion, our results provide insights into the impact of solute concentration on ice formation and devitrification during rapid cooling, which can be practical for optimizing cryopreservation protocols.

Synthesis and self-assembly of poly(4-vinylphenol)-b-poly(vinyl alcohol) diblock copolymer for invertible core-shell nanoparticles

We report the synthesis of the amphiphilic diblock copolymer, poly (vinyl phenol)-block-poly (vinyl alcohol), and its reversible formation of invertible core-shell nanoparticles. The diblock copolymer composed of poly (4-vinylphenol) (P4VPh) and poly (vinyl alcohol) (PVA) was prepared by the switchable reversible addition-fragmentation chain transfer polymerization (switchable-RAFT) of 4-acetoxystyrene and vinyl acetate and subsequent acetyl deprotection. The diblock copolymer was soluble in dimethyl sulfoxide (DMSO) but self-assembled into core-shell nanoparticles with the addition of H2O or tetrahydrofuran (THF). The formation and transition of the invertible core-shell system in response to solvent composition was characterized by 1H NMR, dynamic light scattering, and transmission electron microscopy. Interestingly, the fluorescent behavior of the P4VPh block was changed according to the morphological change of core-shell nanoparticle induced by solvent composition. With increasing the H2O content, the P4VPh chains in the DMSO solution collapsed and the diblock copolymers self-assembled to core-shell type micelles. Aggregation of P4VPh chains increased the local concentration of the phenolic group, resulting in fluorescence quenching. However, with the addition of THF to the DMSO solution, the inverted core-shell nanoparticles were formed where segregated P4VPh chains showed fluorescence.

Inorganic Polysulfides in Solution: Structural Properties and Conformational Isomerism.

We present a comprehensive theoretical examination of the structural properties of dianionic polysulfides [Sn]2- (n = 2-6), their conjugated monoacids [HSn]- (n = 2-6), and a selection of 1e--oxidized radical anions [Sn]•- (n = 2-4), in aqueous and dimethyl sulfoxide (DMSO) solutions. We investigated the structures and stabilities of various conformational isomers within these families of compounds by employing Quantum Mechanics-Molecular Mechanics (QM-MM) Molecular Dynamics (MD) simulations. The explicit inclusion of solvent molecules in the calculations revealed stable conformational structures that were previously unreported and might have appreciable concentrations in real systems. The interconversions between the isomeric structures proceed on the order of hundreds of picoseconds and are energetically similar to the isomerization processes in substituted cyclohexanes. We also conducted a detailed analysis of the stability of different isomers of the radical anion [S4]•- in solution. Our findings highlight the significant influence of the solvent on the isomerizations, a result that could be particularly relevant for enhancing the performance of metal-sulfur batteries.

Cryopreservation of date palm tissue cultures by vitrification and assessment of genetic stability using ISSR analysis

In this work, a successful cryopreservation method of date palm tissue cultures by vitrification was established. Callus and somatic embryos of three date palm cultivars were exposed to dimethylsulfoxide (DMSO) and Plant Vitrification Solution 2 (PVS2) for different durations before plunging into liquid nitrogen for cryoprotection. After freezing phase, the cryopreserved cultures were thawed and cultured on recovery media. Among different times of exposure to DMSO (10%), 60 min gave best results of survival and regrowth of the date palm tissue cultures. Regarding recovery, ‘Zaghlool’ cultivar gave the highest values of callus fresh mass (0.5 g) and growth value (1.00). Also, the highest differentiation percentages (75%) and number of proliferated shootlets (8.50) were recorded with ‘Zaghlool’ cultivar. Concerning PVS2, survival and regrowth gradually increased as exposure time increasing till 30 min and then decreased. Unlike of callus cultures, the survival and regrowth rates of somatic embryos were relatively higher at all PVS2 exposure time. With regard to recovery, the genotype effect took same trend in cryopreservation of callus cultures, since ‘Zaghlool’ was superior in growth parameters in comparison to the other two cultivars. On the other hand, genetic stability of the cryopreserved date palm tissue cultures was assessed using ISSR markers. Among four screened primers, three gave monomorphic bands; all of these banding profiles were similar to those of non-cryopreserved cultures. Generally, the results of ISSR showed high genetic similarity suggesting that cryopreservation using vitrification does not affect genetic stability of date palm tissue cultures. The results of this study demonstrated PVS2 was more effective in cryoprotection of date palm tissue cultures compared with DMSO and cryopreservation by vitrification is a suitable tool for conservation of genetic stable date palm germplasm.