Free Groups Research Articles

Acidic Environment-Responsive Metal Organic Framework-Mediated Dihydroartemisinin Delivery for Triggering Production of Reactive Oxygen Species in Drug-Resistant Lung Cancer.

Dihydroartemisinin (DHA) has emerged as a promising candidate for anticancer therapy. However, the application of DHA in clinics has been hampered by several limitations including poor bioavailability, short circulation life, and low solubility, significantly restricting its therapeutic efficacy and leading to notable side effects during the treatment. We present DHA-loaded zeolitic imidazolate framework-8 (D-ZIF) with controllable and targeted DHA release properties, leading to enhanced antitumor effects while reducing potential side effects. D-ZIF was prepared by one-pot synthesis method using methylimidazole (MIM), Zn(NO3)2•6H2O and DHA. We characterized the physical and chemical properties of D-ZIF by TEM, DLS, XRD, FT-IR, and TG. We measured the drug loading efficiency and the cumulative release of DHA in different pH conditions. We evaluated the cytotoxicity of D-ZIF on renal cell carcinoma (RCC786-O), glioma cells (U251), TAX-resistant human lung adenocarcinoma (A549-TAX) cells by CCK8 in vitro. We explored the possible antitumor mechanism of D-ZIF by Western blot. We evaluated the biocompatibility and hemolysis of D-ZIF and explored the in vivo antitumor efficiency in mice model by TUNEL testing and blood biomarker evaluations. D-ZIF showed rhombic dodecahedral morphology with size of 129±7.2 nm and possessed a noticeable DHA encapsulation efficiency (72.9%). After 48 hours, D-ZIF released a cumulative 70.0% of the loaded DHA at pH 6.5, and only 42.1% at pH 7.4. The pH-triggered programmed release behavior of D-ZIF could enhance anticancer effect of DHA while minimizing side effects under normal physiological conditions. Compared with the free DHA group with 31.75% of A549-TAX cell apoptosis, the percentage of apoptotic cells was approximately 76.67% in the D-ZIF group. D-ZIF inhibited tumor growth by inducing tumor cell apoptosis through the mechanism of ROS production and regulation of Nrf2/HO-1 and P38 MAPK signaling pathways. D-ZIF showed potent effects in treating tumors with high safety in vivo. This pH-responsive release mechanism enhanced the targeting efficiency of DHA towards tumor cells, thereby increasing drug concentration in tumor sites with negligible side effects. Herein, D-ZIF holds great promise for curing cancers with minimal adverse effects.

Effect of pH‐shifting treatment on the structural characteristics and nutritional quality of the ultrasonically extracted protein isolate from soybean meal

AbstractSoybean meal is an underutilized byproduct of the soybean oil processing industry, which is rich in high quality protein but mostly used as an animal feed. Valorization of soybean meal on a large scale is possible by extracting protein isolate and modifying its structural characteristics through pH‐shifting or ultrasonic treatment, which has a direct association with the better functional properties of protein isolate. The present study aimed to evaluate the impact of pH‐shifting treatment on the structural characteristics and nutritional quality of ultrasonically extracted soybean meal protein isolate (SMPI). The results showed that the pH shifted SMPI had higher hydrophobicity (60.5–104.3) and free sulfhydryl group (22.67–24.45 μmol/g) than without pH shifted SMPI (53.5 and 19.67 μmol/g, respectively). The fluorescence intensity of the SMPI treated at extreme acidic and alkaline pH was higher than that of other pH‐treated samples. The ꞵ‐sheet (39.68%) components of SMPI treated at pH 10 showed the highest value when compared to other pH‐treated (38.18–39.26%). The alkaline pH‐treated sample had higher concentration of essential amino acids (36.16 g/100 g) than other acidic or near neutral pH‐treated sample (30.06–32.30 g/100 g). The quality parameters such as biological value (67.62), and amino acid index (72.77) were higher for the SMPI treated at pH 10 as compared to the SMPI treated at other pH conditions. Hence, the pH‐treatment method can be utilized as an effective technique to improve the characteristics of SMPI, which will increases its applications in various food sectors.Practical ApplicationsThe current investigation demonstrated that pH‐shifting treatment had a substantial impact on the structural and nutritional quality of the soybean meal protein isolate extracted by ultrasonication. Improvements in soybean meal protein's surface hydrophobicity, free sulfhydryl groups, and secondary structural components will expand its uses in the dairy, bread, meat, and infant food development industries, among other food sectors as these structural changes improve the functionality of protein. Furthermore, the treatment of soybean meal protein isolate with pH shifting led to a considerable increase in nutritional quality, as measured by the essential amino acid composition, essential amino acid index, and protein efficiency ratio, which is expected to increase its utilization in novel food product development.

The effects of advanced glycation end-products on skin and potential anti-glycation strategies.

The advanced glycation end-products (AGEs) are produced through non-enzymatic glycation between reducing sugars and free amino groups, such as proteins, lipids or nucleic acids. AGEs can enter the body through daily dietary intake and can also be generated internally via normal metabolism and external stimuli. AGEs bind to cell surface receptors for AGEs, triggering oxidative stress and inflammation responses that lead to skin ageing and various diseases. Evidence shows that AGEs contribute to skin dysfunction and ageing. This review introduces the basic information, the sources, the metabolism and absorption of AGEs. We also summarise the detrimental mechanisms of AGEs to skin ageing and other chronic diseases. For the potential strategies for counteracting AGEs to skin and other organs, we summarised the pathways that could be utilised to resist glycation. Chemical and natural-derived anti-glycation approaches are overviewed. This work offers an understanding of AGEs to skin ageing and other chronic diseases and may provide perspectives for the development of anti-glycation strategies.

1139 Retrospective Review of Stereotactic Electroencephalogram Recordings in Temporal Lobectomy Patients Demonstrates the Predictive Value of Interictal Cross-frequency Correlations

INTRODUCTION: Positive correlations between low and high frequency spectra in invasive electroencephalogram (EEG) have been implicated in pathological brain activity interictally and have been used for ictal detection in both focal and network models. METHODS: We retrospectively analyzed interictal signals from 22 patients who underwent SEEG at our institution between 12/2/14 to 12/8/20. We then analyzed significant HG/Beta cross-frequency correlations using similar processing to our previous publication. These signals were then separated based on temporal and extra-temporal locations. We further evaluated any statistical differences between the seizure free (SF) and non-seizure free (NSF) groups, and mesial (M) versus mesial temporal-plus (M+) onset location. RESULTS: 1) Clinical recordings from SEEG electrodes can detect cross-frequency correlations between HG/Beta using our previous methodology. 2) Positive correlations are significantly increased in temporal versus other sampled areas. 3) Positive correlations are more predictive of seizure onset during asleep recordings. 4) NSF patients show a significantly higher proportion of positive electrodes in the resected temporal lobe than SF patients. 5) SF patients have a greater proportion of significant contacts in the mesial versus the lateral temporal lobe than NSF patients. 6) Significant HG/Beta correlations in the mesial versus lateral temporal lobe predict seizure freedom better than ictal SEEG localization of seizure onset to M or M+ locations. CONCLUSIONS: We present preliminary data that local HG/Beta correlations may be predictive for epilepsy focus and surgical outcome and may have utility as adjunct methods to conventional SEEG analysis. Further studies are needed to determine strategies for prospective studies and clinical use.

Polyester networks based on Tulipalin A and ε‐caprolactone and activation of the Thioether groups by incorporation of trialkylsulfonium salts

AbstractLinear and star‐shaped poly(ε‐caprolactone‐co‐α‐methylene‐γ‐butyrolactone) P(CL‐co‐MBL) copolyesters with a pendant functional double bond of α‐methylene‐γ‐butyrolactone (MBL) comonomer were used as polymeric precursor for organo‐gels formation. Crosslinking was carried out by light‐initiated thia‐Michael reaction using 1,5‐pentanedithiol (PDT) and pentaerythritol tetrakis(3‐mercaptopropionate) (PETK). Double bond conversion and the content of free thiol groups in the obtained networks was followed and rationally estimated using confocal Raman spectroscopy. The gel content and the crosslinking density varied based on MBL comonomer and crosslinker content and were highest for slight thiol to double bond excess (SH/vinyl; 2/1 molar ratio) while decreasing with further thiol excess. These parameters were more pronounced by the replacement of linear PDT with the star‐shaped PETK crosslinker. The thermal and rheological properties investigation of the obtained materials was performed employing DSC, TGA and using frequency and temperature sweeps rheological measurements. Shear moduli in the range 0.14 up to 0.93 MPa were obtained due to different content of MBL in pre‐polymer and crosslinker in network formation. The strength was caused by the crystalline phase of the PCL segments up to a temperature of 50°C. Formed thioether bond within the network were not reversible up to 150°C as it was found based on temperature sweep rheology. Following, the activation and conversion of thioether bonds within the obtained materials into trialkylsulfonium salts was attained through the alkylation using butyl brosylate. The dynamic nature of the transalkylation at elevated temperature 150°C allowed network rearrangement, which was proved by stress relaxation experiment and investigation of the self‐healing capabilities.

An Analogue of the Strengthened Hanna Neumann Conjecture for Virtually Free Groups and Virtually Free Products

An Analogue of the Strengthened Hanna Neumann Conjecture for Virtually Free Groups and Virtually Free Products

Corrigendum: Model theory of fields with virtually free group actions

AbstractThere is an irreparable error in the proof of Theorem 3.26 in the above‐mentioned paper and we withdraw the claim of having proved that theorem. In fact, that theorem is false in a very strong sense.

Serum Fructosamine as a Marker for Glycemic Control in Patients with Diabetic Nephropathy

Diabetes mellitus (DM) is a metabolic disease of chronic insulin deficiency or resistance. The progression of DM is associated with long-term damage to macro- and micro-vascular body systems and causes serious health complications. Up to 40% of DM patients develop chronic kidney disease (CKD), mainly as a consequence of diabetic nephropathy (DN). Hence, strict glycemic control is recommended to slow down CKD progression. Hyperglycemia causes complications in diabetic patients through the glycation of various proteins. The interaction of glucose with the free NH2 groups of proteins results in the formation of the early glycation product fructosamine (FA). FA has a short half-life (1 to 2 weeks) and hence it has the potential of an early marker for glycemic control. Although long used in the clinical practice, the FA diagnostic and prognostic significance remains questionable. In this study, we tested the FA potential to serve as a glycemic marker in DM patients with DN. We found that DM patients have significantly higher serum FA levels than non-diabetics. Further, the serum FA level in diabetics correlates positively with the blood glucose concentration. Finally, the mean serum FA level was higher in DM patients with DN, compared to those without DN. These results establish FA as a promising marker for glycemic control in DN patients.

Soybean isolate protein complexes with different concentrations of inulin by ultrasound treatment: Structural and functional properties

The effects of ultrasound and different inulin (INU) concentrations (0, 10, 20, 30, and 40 mg/mL) on the structural and functional properties of soybean isolate protein (SPI)-INU complexes were hereby investigated. Fourier transform infrared spectroscopy showed that SPI was bound to INU via hydrogen bonding. All samples showed a decreasing and then increasing trend of α-helix content with increasing INU concentration. SPI-INU complexes by ultrasound with an INU concentration of 20 mg/mL (U-2) had the lowest content of α-helix, the highest content of random coils and the greatest flexibility, indicating the proteins were most tightly bound to INU in U-2. Both UV spectroscopy and intrinsic fluorescence spectroscopy indicated that it was hydrophobic interactions between INU and SPI. The addition of INU prevented the exposure of tryptophan and tyrosine residues to form a more compact tertiary structure compared to SPI alone, and ultrasound caused further unfolding of the structure of SPI. This indicated that the combined effect of ultrasound and INU concentration significantly altered the tertiary structure of SPI. SDS-PAGE and Native-PAGE displayed the formation of complexes through non-covalent interactions between SPI and INU. The ζ-potential and particle size of U-2 were minimized to as low as −34.94 mV and 110 nm, respectively. Additionally, the flexibility, free sulfhydryl groups, solubility, emulsifying and foaming properties of the samples were improved, with the best results for U-2, respectively 0.25, 3.51 μmoL/g, 55.51 %, 269.91 %, 25.90 %, 137.66 % and 136.33 %. Overall, this work provides a theoretical basis for improving the functional properties of plant proteins.

Mechanism of ultrasound-induced soybean/egg white composite gelation: Gel properties, morphological structure and co-aggregation kinetics

This study aims to develop ultrasound-assisted acid-induced egg white protein (EWP)-soy protein isolate (SPI) composite gels and to investigate the mechanistic relationship between the co-aggregation behavior of composite proteins and gel properties through aggregation kinetics monitored continuously by turbidity. The results showed that the inclusion of EWP caused the attenuation of gel properties and maximum aggregation (Amax) because EWP could aggregate with SPI at a higher rate (Kapp), which impeded the interaction between SPI and the formation of a continuous gelling network. In the EWP-dominated system, SPI with higher molecular weights also increased the fractal dimension of gels. Ultrasound improved properties of composite gels, especially the SPI-dominated system. After ultrasound treatment, the small, uniform size of co-aggregates and the decrease in potential led to an increase in the aggregation rate and formation of dense particles, consistent with an increase in gelation rate and texture properties. Excessively fast aggregation generated coarse chains and more pores. Still, the exposure of free sulfhydryl groups assisted the gel structure units to form a compact network through disulfide bonding. On the whole, the study could provide theoretical support for a deeper understanding on the interaction mechanism and gelation of composite proteins.

Efficient recovery of Cr(VI), Au(III), and Pd(II) using physically crosslinked aminoclay/polyvinyl alcohol composite microgels generated by microfluidics

Chemically crosslinked hydrogel adsorbents are typically produced using highly toxic agents for crosslinking, posing risks to both human health and the environment. In this study, we successfully demonstrated the fabrication of a physically crosslinked Fe–aminoclay (AC)/polyvinyl alcohol (PVA) composite microgel. This was achieved using a microfluidic approach to generate water-in-oil-in-water (W/O/W) double-emulsion droplets, eliminating the need for chemical crosslinkers. Compared to its chemically crosslinked counterpart, this physically crosslinked Fe–AC/PVA microgel showed superior performance in recovering the metals Cr(VI), Au(III), and Pd(II) from an aqueous solution. This enhanced capability was attributed to the abundance of free amine functional groups and a microgel structure that was conducive to metal ion adsorption. The physically crosslinked microgel demonstrated a maximum adsorption capacity of 203.7 mg/g for Cr(VI), 241.3 mg/g for Au(III), and 275.8 mg/g for Pd(II), compared to 144.3, 181.1, and 222.5 mg/g, respectively, for the chemically crosslinked microgel. The adsorption isotherms and kinetics for these metals conformed to the Sips isotherm and pseudo-second-order models, respectively, suggesting that chemical adsorption was the dominant mechanism. Furthermore, embedding magnetic nanoparticles in the Fe–AC/PVA microgel enabled straightforward separation and regeneration from an aqueous solution. The Fe–AC/PVA composite microgel also demonstrated excellent reusability, maintaining an adsorption efficiency of over 78 % across five consecutive cycles.

Developing three-dimensional spatial embodiment in architectural design education: underwater experiences

ABSTRACT Three-dimensional thinking, observation, and practice have long been an important part of architectural education. Reduced awareness of corporeality and the senses can impair a student’s capacity to create and develop an architectural environment holistically. Simulation programmes are an important tool to fill this gap, as they can broaden a student’s perceptual framework. This article aims to understand the potential of underwater contact experiences to serve this purpose, especially underwater (UW) rugby which is one of the few sports that is three-dimensional. The article also aims to understand how simulation programmes, virtual reality, or augmented environments of UW rugby can contribute to design and architecture education by increasing student awareness. The article is grounded in the impact of this sport on the author and the author’s perceptions based on personal experience as a former UW rugby player. It is argued that the simulation of UW rugby can contribute to design-related topics such as free form-finding, role-sharing and group collaboration, the development of awareness to sensorial design processes, risk- taking and action-oriented processes, designing with environmental uncertainty, and even design management, as these immersive environments provide a new agenda for future designers. Due to practical limitations, the article presents a theoretical argument as a first step toward developing a theoretical framework. Future studies with cognitive research methods and quantitative approaches in sports simulation design research will address these constraints.

Soy protein isolate-catechin complexes conjugated by pre-heating treatment for enhancing emulsifying properties: Molecular structures and binding mechanisms

This study aimed to investigate the impact of different pre-heating temperatures (ranging from 40 °C to 80 °C) on the interactions between soy protein isolate (SPI) and catechin to effectively control catechin encapsulation efficiency and optimize the emulsifying properties of soy protein isolate. Results showed that optimal heat treatment at 70 °C improved catechin encapsulation efficiency up to 93.71 ± 0.14 %, along with the highest solubility, enhanced emulsification activity index and improved thermal stability of the protein. Multiple spectroscopic techniques revealed that increasing pretreatment temperature (from 40 °C to 70 °C) altered the secondary structures of SPI, resulting in a more stable unfolded structure for the composite system with a significant increase in α-helical structures and a decrease in random coil and β-sheet structures. Moreover, optimal heat treatment also leads to an augmentation of free sulfhydryl groups within complex as well as exposure of more internal chromophore amino acids on molecular surface. Size-exclusion high-performance liquid chromatography and SDS-PAGE analysis indicated that the band intensity of newly formed high-molecular-weight soluble macromolecules (>180 kDa) increased as the pre-heating temperature rose. Furthermore, fluorescence spectroscopy and molecular docking analysis suggest that hydrophobic and covalent interactions were involved in complex formation, which intensified with increasing temperature.

Tracially amenable actions and purely infinite crossed products

AbstractWe introduce the notion of tracial amenability for actions of discrete groups on unital, tracial C$$^*$$ ∗ -algebras, as a weakening of amenability where all the relevant approximations are done in the uniform trace norm. We characterize tracial amenability with various equivalent conditions, including topological amenability of the induced action on the trace space. Our main result concerns the structure of crossed products: for groups containing the free group $$F_2$$ F 2 , we show that outer, tracially amenable actions on simple, unital, $$\mathcal {Z}$$ Z -stable C$$^*$$ ∗ -algebras always have purely infinite crossed products. Finally, we give concrete examples of tracially amenable actions of free groups on simple, unital AF-algebras.

Formation of casein micelles from bovine caseins simulating human casein phosphorylation patterns: Micellar structure and in vitro infant gastrointestinal digestion

This study investigated the micellar structure and in vitro infant gastrointestinal digestion of formed casein micelles simulating human casein composition and phosphorylation patterns. Caseins were fractionated from bovine caseins and formulated according to human casein composition, i.e., β-, κ- and αs1-caseins with a ratio of 68:20:12. The formulated caseins were dephosphorylated for different times and were mixed to obtain mixed phosphorylation patterns (FC-MP) for β-casein, showing 0–5 phosphate groups comparable to human β-casein. The formulated caseins without dephosphorylation and with high dephosphorylation, showing 5 phosphate groups and 0–2 phosphate groups for β-casein, respectively, were categorized as high (FC-HP) and low phosphorylated (FC-LP). With the average mineral concentrations found in human milk, CaCl2, MgCl2, citrate and inorganic phosphate were added into the different formulated casein dispersions to obtain casein micelles (FM-HP, FM-MP and FM-LP). Compared to FM-HP, FM-MP was closer to human micelles in relation to particle size, micellar hydration, molar ratio of Ca:casein, morphology and internal structure, whereas FM-LP showed did not show a characteristic micellar structure and had a larger size and lower molar ratio of Ca:casein. For gastrointestinal digestion, FM-MP was closer to human micelles in terms of the gastric flocs, casein degradation rate, free amino groups, and molecular weight distribution of peptides compared to FM-HP, whereas FM-LP showed larger flocs and lower casein degradation rate. These results show the significance of post-translational phosphorylation in facilitating the assembly of caseins into micellar structures, indicating the potential to form human-like micelles for application in infant formulae.

The compressed conjugacy problem in relatively hyperbolic groups

We prove that the compressed conjugacy problem in a group that is hyperbolic relative to a collection of free abelian subgroups is solvable in polynomial time.

Free groups generated by two unipotent maps

Abstract Let A and B be two unipotent elements of SU ⁢ ( 2 , 1 ) {\mathrm{SU}(2,1)} with distinct fixed points. In [S. B. Kalane and J. R. Parker, Free groups generated by two parabolic maps, Math. Z. 303 2023, 1, Paper No. 9], the authors gave several conditions that guarantee the subgroup 〈 A , B 〉 {\langle A,B\rangle} is discrete and free by using Klein’s combination theorem. We will improve their conditions by using a variant of Klein’s combination theorem. With the same arguments and the additional assumption that AB is unipotent, we also extend Parker and Will’s condition that guarantees the subgroup 〈 A , B 〉 {\langle A,B\rangle} is discrete and free in [J. R. Parker and P. Will, A complex hyperbolic Riley slice, Geom. Topol. 21 2017, 6, 3391–3451].

Structure–activity relationship and biofilm formation-related gene targets of oleanolic acid-type saponins from Pulsatilla chinensis against Candida albicans

In the course of our investigations of antifungal natural products, the structure–activity relationship and antifungal activities of oleanolic acid-type saponins (1–28) from Pulsatilla chinensis against human and plant pathogenic fungi were elucidated. The analysis of structure–activity relationship of oleanolic acid-type saponins showed that the free carboxyl at C-28 was essential for their antifungal activities; the free hydroxyl group at the C-23 site of oleanolic acid-type saponins played a crucial role in their antifungal activities; the oligosaccharide chain at C-3 oleanolic acid-type saponins showed significant effects on antifungal efficacy and a disaccharide or trisaccharide moiety at position C-3 displayed optimal antifungal activity. The typical saponin pulchinenoside B3 (16, PB3) displayed satisfactory antifungal activity against human and plant pathogenic fungi, especially, C. albicans with an MIC value of 12.5 μg/mL. Furthermore, PB3 could inhibit the biofilm formation of C. albicans through downregulating the expression of the integrated network of biofilm formation-associated transcription factors (Bcr1 Efg1, Ndt80, Brg1, Rob1 and Tec1) and adhesion-related target genes (HWP1, ALS1, and ALS3). Meanwhile, we found that PB3 could effectively destroy the mature biofilm of C. albicans by the oxidative damage and inducing mitochondria-mediated apoptosis in cells.

Enhanced viability and membrane lipid stability of cholesterol-lowering probiotics through spray drying encapsulation with whey protein isolate-coconut oil complex

This study assessed the effect of whey protein isolate (WPI) and its coconut oil complexes (CO-WPI) on the viability of Limosilactobacillus reuteri KUB-AC5 during spray drying and storage. Varied CO concentrations (0%, 4%, and 8%, w/w) and spray drying temperatures (110 °C and 130 °C) influenced secondary structures, free sulfhydryl groups, disulfide bonds, and DPPH• and ABTS•+ scavenging activities of WPI. Throughout the spray drying and storage processes, CO-WPI effectively reduced lipid peroxidation in the probiotic membranes, as detected by advanced 1H-nuclear magnetic resonance, compared to WPI alone. Microencapsulation in 4CO-WPI at 110 °C provided the highest cell viability during drying (1.34 × 1011 CFU g−1), coupled with the highest cholesterol assimilation (58.43%). After 12 months at 4 °C, viability remained high (5.57 × 1010 CFU g−1). This study demonstrated CO-WPI's potential in reducing oxidative damage and improving probiotic survival, highlighting its efficacy as a microencapsulant in spray drying.

Synthesis of hybrid nanostructures based on e-carboxy-dihydroxycobinamide and N-(monohydrofullerenyl)-l-fluorophenylalanines

Mono-derivatives of fullerene C60 with l-phenylalanine, o-fluoro-l-phenylalanine and p-fluoro-l-phenylalanine, as well as their hybrid nanostructures with derivatives of vitamin B12, have been synthesised. The structure of the compounds was determined by IR, UV and CD-spectroscopy. The IR spectra of the obtained compounds contain all bands characteristic of the original compounds, with the exception of the band at 1227 cm−1, which is related to the free carboxyl group in the fullerene fragment. In the UV spectra of hybrid nanostructures contain smoothed peaks in the region of 360 nm, confirming the presence of corrin ligand in the original and obtained compounds. Using the CD method, it was found that all spectra have a characteristic maximum in the region of 430 nm, confirming the presence in all hybrids nanostructures of a fragment of vitamin B12: e-COOH-Cbi(OH)2. The radiuses of nanoparticles of hybrid nanostructures, calculated by the dynamic light scattering method, range from 90 to 120 nm. The degree of association in the complexes ranges from 400 to 600 thousand molecules. It was shown that the resulting hybrid nanostructure retains catalytic activity in the autoxidation reaction of ascorbic acid, inherent in derivatives of vitamin B12.